{"license":"https://creativecommons.org/licenses/by-sa/4.0/","updated":"2026-11-03","items":[{"slug":"3d-printer-filament","name":"3D printer filament","kind":"product","category":"plastics","title":"How 3D printer filament is made","url":"https://assemblyline.org/make/3d-printer-filament","stations":6,"upstream":35,"downstream":0,"depth":7,"dek":"Printer filament is plastic pellets melted and pulled into a thread, and a laser checks its width many times a second.","answer":"3D printer filament is made by feeding plastic pellets, called nurdles, into an extruder that heats and melts them. The melt is pulled out through a small die as a continuous thread, cooled in a water bath, measured by a laser gauge that adjusts the pulling speed, and wound neatly onto a spool.","aka":["FDM filament","PLA filament","printer spool"],"inputs":["abs-plastic","pet-plastic"],"uses":[],"grounds":["air","crude-oil","water","natural-gas","iron-ore","sulfur","coal","titanium-ore","corn","limestone","rock-salt","sugarcane","sugar-beet"],"upstreamSlugs":["abs-plastic","pet-plastic","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","p-xylene","ethylene-glycol","crude-oil","water","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","carbon-black","sulfur","oxygen","carbon-dioxide","coal","titanium-ore","chlorine","coke","sulfuric-acid","corn","yeast","limestone","rock-salt","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Dry the pellets","process":"dry","text":"Plastic pellets are dried in a hopper dryer, because moisture would bubble and pop in the melt. Colors and additives are blended in at this stage.","inputs":["abs-plastic","pet-plastic"]},{"name":"Melt and mix in the extruder","process":"melt","text":"A screw carries the pellets along a heated barrel and melts them. The pressure builds up before the die.","inputs":[]},{"name":"Pull the thread through a die","process":"draw","text":"Unlike a printer nozzle that pushes plastic out, a puller draws the filament through the nozzle. The thread is stretched to its final thin diameter.","inputs":[]},{"name":"Cool it in a water bath","process":"chill","text":"The thread passes through a trough of water that sets the plastic. Air knives blow off the water afterwards.","inputs":[]},{"name":"Gauge the diameter","process":"inspect","text":"A laser gauge measures the thread many times a second and tunes the puller speed. Printers expect a steady width, usually 1.75 mm or 2.85 mm.","inputs":[]},{"name":"Wind it onto spools","process":"package","text":"A winder lays the filament in neat layers on a spool, which is vacuum sealed with a desiccant. Tangles would jam a printer mid-job.","inputs":[]}],"facts":["Unlike a printer nozzle that pushes plastic out, a puller draws the filament through the die, and the pulling speed sets its width.","The fused filament fabrication name was coined by the RepRap project to give an acronym that was legally unconstrained in use."],"where":[],"whereNote":null,"sources":[{"title":"3D printing filament","url":"https://en.wikipedia.org/wiki/3D_printing_filament"},{"title":"Fused filament fabrication","url":"https://en.wikipedia.org/wiki/Fused_filament_fabrication"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"aa-battery","name":"AA battery","kind":"product","category":"electronics","title":"How AA batteries are made","url":"https://assemblyline.org/make/aa-battery","stations":8,"upstream":75,"downstream":0,"depth":10,"dek":"An alkaline cell is zinc powder, manganese dioxide and potassium hydroxide in a steel can.","answer":"The can itself is part of the positive electrode. Manganese dioxide, carbon and potassium hydroxide are mixed, granulated and pressed into hollow rings that slide into a nickel-plated steel can. A paper separator lines them, a zinc gel fills the middle, and a brass nail through a plastic seal collects current from the zinc. The result gives 1.5 volts.","aka":["alkaline battery","AA cell","double-A battery"],"inputs":["manganese","carbon-black","potassium-hydroxide","water","steel","nickel","paper","zinc","brass","plastic","plastic-wrap"],"uses":[],"grounds":["water","manganese-ore","iron-ore","natural-gas","crude-oil","air","potash","nickel-ore","kaolin","limestone","zinc-ore","coal","sulfur","dolomite","timber","copper-ore","lead-ore","tin-ore","quartz","rock-salt","bauxite","titanium-ore"],"upstreamSlugs":["manganese","carbon-black","potassium-hydroxide","water","steel","nickel","paper","zinc","brass","plastic","plastic-wrap","manganese-ore","iron-ore","coke","sulfuric-acid","natural-gas","crude-oil","air","potash","pig-iron","magnesium","steel-scrap","oxygen","lime","argon","nickel-ore","wood-pulp","kaolin","limestone","zinc-ore","copper","lead","tin","aluminum","naphtha","ethylene","propylene","pvc","polyethylene","cardboard","coal","sulfur","dolomite","silicon","propane","timber","caustic-soda","hydrogen-peroxide","copper-ore","lead-ore","tin-ore","petroleum-coke","alumina","hydrogen","chlorine","pigment","plasticizer","adhesive","quartz","charcoal","rock-salt","bauxite","titanium-dioxide","acrylic","epoxy","polyurethane","paraffin-wax","titanium-ore","ammonia","methanol","phenol","acetone","nitric-acid","benzene","toluene"],"downstreamSlugs":[],"steps":[{"name":"Mix the cathode","process":"mix","inputs":["manganese","carbon-black","potassium-hydroxide","water"],"text":"Trainloads of manganese dioxide, carbon and potassium hydroxide solution are mixed in very large batches at the plant, then granulated."},{"name":"Press hollow rings","process":"press","inputs":[],"text":"The granules are compacted into hollow cylinders called preforms, and several may stack in one cell. Some makers extrude a single ring of the same material instead."},{"name":"Form the steel can","process":"stamp","inputs":["steel","nickel"],"text":"Large operations cut and form their own nickel-plated steel cans. The preforms are pushed in, and the can and rings together become the positive electrode. A groove near the top gets a sealant to stop leaks."},{"name":"Line with separator","process":"assemble","inputs":["paper"],"text":"Several pieces of paper, laid crossgrain like plywood and soaked in electrolyte, go in like a paper cup. This keeps the two electrodes apart. Some designs use a porous synthetic fiber."},{"name":"Fill with zinc gel","process":"fill","inputs":["zinc","potassium-hydroxide"],"text":"A very thick paste of zinc powder and electrolyte goes in the center. It stops short of the top, leaving room for the chemical reactions in use."},{"name":"Crimp in the seal","process":"assemble","inputs":["brass","plastic"],"text":"A brass nail welded to a metal end cap passes through a plastic seal and reaches about two-thirds of the way down into the gel. The seal has thin spots that rupture first if gas builds up, and it is crimped into the groove."},{"name":"Close the positive end","process":"weld","inputs":["steel"],"text":"A steel plate is welded or glued with an epoxy-type cement over the opposite end of the can, which becomes the battery's positive terminal."},{"name":"Label and test","process":"package","inputs":["plastic-wrap"],"text":"A glued paper label or a loose plastic sleeve goes on, and a blast of heat shrinks the sleeve tight. Ingredients and cells are checked at almost every stage, and finished batches are tested hard."}],"facts":["Lewis Urry invented the modern alkaline dry cell in the 1950s.","An AA alkaline cell might give 3,000 mAh at a light load but as little as 700 mAh when delivering 1 ampere.","In the mid-1980s, alkaline batteries commonly held five to seven percent mercury, added to fight corrosion until purer ingredients replaced it."],"where":[],"whereNote":null,"sources":[{"title":"Battery (How Products Are Made)","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/battery"},{"title":"Alkaline battery","url":"https://en.wikipedia.org/wiki/Alkaline_battery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"abs-plastic","name":"ABS plastic","kind":"material","category":"plastics","title":"How ABS plastic is made","url":"https://assemblyline.org/make/abs-plastic","stations":6,"upstream":24,"downstream":28,"depth":6,"dek":"ABS is a hard plastic with rubber particles grafted into it, which is why a LEGO brick survives being stepped on.","answer":"ABS is made from three ingredients: styrene, acrylonitrile and butadiene. Butadiene is first turned into rubbery particles, and then styrene and acrylonitrile are polymerized around them so the chains tie together. The powder is melted with pigments and cut into pellets for molders.","aka":["acrylonitrile butadiene styrene"],"inputs":["naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment"],"uses":["lipstick","hearing-aid","thermometer","lego-brick","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","ballpoint-pen","snowboard","action-figure","harmonica","globe","suitcase","high-heels","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush"],"grounds":["air","crude-oil","water","natural-gas","iron-ore","sulfur","coal","titanium-ore","rock-salt"],"upstreamSlugs":["naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","crude-oil","water","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","carbon-black","sulfur","coal","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","rock-salt"],"downstreamSlugs":["lipstick","hearing-aid","thermometer","lego-brick","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","ballpoint-pen","snowboard","action-figure","harmonica","globe","suitcase","high-heels","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush"],"steps":[{"name":"Polymerize the rubber balls","process":"react","text":"Butadiene, a byproduct of steam cracking, is polymerized in water into tiny rubbery balls of polybutadiene. These soak up impact like shock absorbers.","inputs":["naphtha"]},{"name":"Build the acrylonitrile","process":"react","text":"Propylene, ammonia and air react over a catalyst to give acrylonitrile, which contributes chemical resistance and stiffness to the plastic.","inputs":["propylene","ammonia","air"]},{"name":"Bring in the styrene","process":"react","text":"Styrene is built from benzene and ethylene, usually at a neighboring plant, and arrives as a liquid. It is the main ingredient by weight, usually between 40% and 60%.","inputs":["benzene","ethylene","styrene"]},{"name":"Graft the chains onto rubber","process":"react","text":"Styrene and acrylonitrile polymerize in the presence of the polybutadiene, growing short chains that cross-link with the rubber. The result is a long rubber backbone crisscrossed with hard side chains.","inputs":[]},{"name":"Coagulate and dry the powder","process":"dry","text":"The latex mixture is coagulated into a crumb, washed, and dried to a fine powder. Recipes shift the balance between toughness, stiffness and heat resistance.","inputs":[]},{"name":"Compound with color","process":"mix","text":"An extruder melts the powder with pigments, stabilizers and lubricants. Strands are chopped into pellets sorted for extrusion or injection molding.","inputs":["pigment"]}],"facts":["Lego bricks have been made mainly from ABS since 1963.","ABS also makes computer keycaps, drain-waste-vent pipe, and plastic recorders, oboes and clarinets.","ABS recipes vary from 15% to 35% acrylonitrile, 5% to 30% butadiene and 40% to 60% styrene."],"where":[],"whereNote":null,"sources":[{"title":"Acrylonitrile butadiene styrene","url":"https://en.wikipedia.org/wiki/Acrylonitrile_butadiene_styrene"},{"title":"Styrene","url":"https://en.wikipedia.org/wiki/Styrene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"acetaminophen","name":"Acetaminophen","kind":"product","category":"body-health","title":"How acetaminophen is made","url":"https://assemblyline.org/make/acetaminophen","stations":6,"upstream":16,"downstream":0,"depth":6,"dek":"Acetaminophen plants reach one intermediate, 4-aminophenol, then bolt on an acetyl group in the last reaction.","answer":"Acetaminophen, also called paracetamol, comes from chemical plants that start with a nitrated aromatic such as p-nitrophenol. Hydrogen reduces that to 4-aminophenol, and acetic anhydride adds an acetyl group to make the crude drug. Charcoal strips the color, repeated crystallization and centrifuging purify it, and the crystals are dried, ground and packed for tablet and syrup makers.","aka":["paracetamol","Tylenol","APAP"],"inputs":["phenol","nitric-acid","hydrogen","acetic-anhydride","water"],"uses":[],"grounds":["water","air","natural-gas","crude-oil","coal"],"upstreamSlugs":["phenol","nitric-acid","hydrogen","acetic-anhydride","water","benzene","propylene","air","ammonia","natural-gas","methanol","carbon-monoxide","naphtha","toluene","crude-oil","coal"],"downstreamSlugs":[],"steps":[{"name":"Prepare the nitro compound","process":"react","text":"A classical route treats phenol with nitric acid. One plant design in an Intratec report starts instead from 4-nitrochlorobenzene and caustic soda in an autoclave. The product, p-nitrophenol, is purified by crystallizing and centrifuging.","inputs":["phenol","nitric-acid"]},{"name":"Reduce it with hydrogen","process":"react","text":"Hydrogen gas and the nitro compound meet in a reactor over a metal catalyst, giving 4-aminophenol. The mixture is cooled and filtered to recover the catalyst.","inputs":["hydrogen"]},{"name":"Add the acetyl group","process":"react","text":"The 4-aminophenol solution enters a second reactor with acetic anhydride and is heated. This acetylation completes the molecule and yields the crude drug.","inputs":["acetic-anhydride"]},{"name":"Decolorize with charcoal","process":"wash","text":"Crude product is taken up in water with some sulfuric acid and treated with decolorizing charcoal, which removes the off color.","inputs":["water"]},{"name":"Crystallize and spin","process":"separate","text":"Purification runs through repeated crystallization, with centrifuges pulling the crystals from their liquid each time.","inputs":[]},{"name":"Dry, grind and pack","process":"crush","text":"Crystals are dried, then ground under dry air and packed for storage. Formulators later press the powder into tablets or dissolve it into syrups.","inputs":[]}],"facts":["Harmon Northrop Morse first made paracetamol in 1877, but it was not tried on humans until 1887.","Paracetamol was shelved in favor of phenacetin for decades because of an early claim, which two research teams challenged in 1947."],"where":[],"whereNote":null,"sources":[{"title":"Paracetamol production cost reports, Intratec","url":"https://intratec.us/analysis/paracetamol-production-cost-paracetamol-production-from-p-nitrochlorobenzene"},{"title":"Paracetamol","url":"https://en.wikipedia.org/wiki/Paracetamol"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"acetic-anhydride","name":"Acetic anhydride","kind":"material","category":"chemicals","title":"How acetic anhydride is made","url":"https://assemblyline.org/make/acetic-anhydride","stations":5,"upstream":4,"downstream":8,"depth":2,"dek":"Water slowly turns acetic anhydride back into acetic acid, so plants keep the whole process bone dry.","answer":"Acetic anhydride is a colorless liquid with a sharp vinegar smell. The largest commercial plants make it from methyl acetate and carbon monoxide, using a rhodium catalyst and an iodide promoter in a loop kept free of water. A flash step returns the catalyst, and distillation gives the product. Its main customer is the cellulose acetate industry.","aka":["ethanoic anhydride","Ac2O"],"inputs":["methanol","carbon-monoxide"],"uses":["aspirin","acetaminophen","ibuprofen","cellulose-acetate"],"grounds":["natural-gas","water"],"upstreamSlugs":["methanol","carbon-monoxide","natural-gas","water"],"downstreamSlugs":["aspirin","acetaminophen","ibuprofen","cellulose-acetate","sunglasses","dice","shoelace","eyeglass-frame"],"steps":[{"name":"Make methyl acetate","process":"react","text":"Plants begin with methyl acetate, an ester made by reacting methanol with acetic acid. An integrated site gets much of that acid from its own later steps.","inputs":["methanol"]},{"name":"Run the carbonylation loop","process":"react","text":"Carbon monoxide with a little hydrogen, which keeps the catalyst active, meets the ester in pressure reactors in liquid phase. The chemistry goes through methyl iodide and acetyl iodide. Water stays out, because it would break the product back down, and keeping the catalyst stable without it is the central problem.","inputs":["carbon-monoxide"]},{"name":"Flash off the light liquids","process":"separate","text":"Leaving the reactor, the liquid enters a flash tank or evaporator. Lighter components boil off toward purification, while the rhodium and other heavy material go back to the reactor.","inputs":[]},{"name":"Distill the crude liquid","process":"refine","text":"Distillation splits the finished liquid from acetic acid and other light components, which return to the process.","inputs":[]},{"name":"Recycle the co-product","process":"react","text":"At a cellulose acetate site, the product reacts with cellulose and frees acetic acid in the process. That acid goes back to meet methanol and form more methyl acetate, closing the circle.","inputs":[]}],"facts":["An integrated plant can turn out cellulose acetate from only methanol, carbon monoxide and cellulose, with no outside acetic acid.","The older ketene route to acetic anhydride dates to 1922, when Wacker Chemie was chasing demand for cellulose acetate."],"where":[],"whereNote":null,"sources":[{"title":"Acetic anhydride","url":"https://en.wikipedia.org/wiki/Acetic_anhydride"},{"title":"US8450524B2, Process for producing carboxylic acid anhydrides","url":"https://patents.google.com/patent/US8450524B2/en"},{"title":"US4234719A, Preparation of cellulose acetate","url":"https://patents.google.com/patent/US4234719"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"acetone","name":"Acetone","kind":"material","category":"chemicals","title":"How acetone is made","url":"https://assemblyline.org/make/acetone","stations":5,"upstream":10,"downstream":192,"depth":5,"dek":"Nail polish remover is a by-product. Plants that make phenol get acetone from the very same split.","answer":"About 83% of the world's supply comes out of the cumene process. Benzene and propylene combine into cumene, air turns that into a hydroperoxide, and acid splits it into phenol and acetone at the same time. Columns separate the two, and most of this volatile solvent heads for paint, plastics and, in small part, nail polish remover.","aka":["propanone","2-propanone","dimethyl ketone","nail polish remover"],"inputs":["benzene","propylene","air"],"uses":["polycarbonate","epoxy","shoelace","eyeglass-frame","cellulose-acetate"],"grounds":["air","crude-oil","water","natural-gas","coal"],"upstreamSlugs":["benzene","propylene","air","naphtha","hydrogen","toluene","crude-oil","water","natural-gas","coal"],"downstreamSlugs":["polycarbonate","epoxy","shoelace","eyeglass-frame","cellulose-acetate","led-bulb","drone","eyeglass-lens","sunglasses","bike-helmet","blender","suitcase","smartwatch","wireless-earbuds","phone-charger","digital-camera","camera-lens","compact-disc","game-console","thermometer","adhesive","printed-circuit-board","wind-turbine","electric-motor","rebar","aluminum-can","airplane","surfboard","ski","snowboard","tennis-racket","fishing-rod","prosthetic-leg","loudspeaker","umbrella","dice","adhesive-bandage","credit-card","duct-tape","ev-battery","pencil","nail","insulation","popcorn","windshield","skateboard","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","pencil-eraser","clear-tape","staple","sofa","ice-skates","golf-club","volleyball","cricket-bat","dartboard","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","globe","snow-globe","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","brake-pad","sailboat","dress-shirt","suit","raincoat","handbag","wallet","flip-flops","hiking-boots","high-heels","microphone","e-reader","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","sneaker","leather-shoe","baseball-cap","carpet","mattress","diaper","hearing-aid","pacemaker","smartphone","laptop","television","hard-drive","solid-state-drive","computer-keyboard","computer-mouse","microwave-oven","washing-machine","satellite","car","electric-car","airbag","rocket","locomotive","motorcycle","elevator","ceiling-fan","treadmill","smoke-detector","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","refrigerator","vacuum-cleaner","dishwasher","air-conditioner","subway-train","concrete","skyscraper","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","aluminum-window-frame","shipping-container","toothbrush","fireworks","plastic-wrap","trading-cards","cake-mix","hair-dye","tampon","soap","toothpaste","detergent","plastic-bag","nitrile-glove","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","cough-syrup","wheelbarrow","light-switch","facial-tissue","aa-battery","candy-cane","syringe"],"steps":[{"name":"Combine the two feedstocks","process":"react","text":"Benzene and propylene are compressed together over an acid catalyst and form cumene. Both are cheap refinery chemicals, and the point of the process is that two products worth more come out the far end.","inputs":["benzene","propylene"]},{"name":"Oxidize with air","process":"react","text":"Air and a small amount of a radical initiator turn cumene into cumene hydroperoxide through a chain reaction. This intermediate is kept under strict control in closed vessels.","inputs":["air"]},{"name":"Break the hydroperoxide","process":"react","text":"An acidic medium rearranges the molecule and splits it in two. One half is phenol, and the other half is a small three-carbon ketone. Output of each is tied to the other, so demand for both has to hold up.","inputs":[]},{"name":"Separate in columns","process":"refine","text":"Distillation pulls apart the mixture. This product boils first, at 56.2 °C, far below phenol, so it comes off the top as a clear and flammable liquid.","inputs":[]},{"name":"Ship the solvent","process":"fill","text":"Tankers take about a third of it to solvent users and a quarter to make methyl methacrylate. Bisphenol A plants, for polycarbonate and epoxy, take another large share.","inputs":[]}],"facts":["People exhale 1.2 to 2.5 mg of acetone per day, since the human body makes small quantities of it.","During the First World War, Chaim Weizmann developed a bacterial fermentation to make acetone for the British war effort.","World production capacity was estimated at 6.7 million tonnes per year in 2010."],"where":[],"whereNote":null,"sources":[{"title":"Acetone","url":"https://en.wikipedia.org/wiki/Acetone"},{"title":"Cumene process","url":"https://en.wikipedia.org/wiki/Cumene_process"},{"title":"Acetone (Britannica)","url":"https://www.britannica.com/science/acetone"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"guitar","name":"Acoustic guitar","kind":"product","category":"play","title":"How acoustic guitars are made","url":"https://assemblyline.org/make/guitar","stations":8,"upstream":54,"downstream":0,"depth":8,"dek":"A guitar's thin spruce top is a speaker. Braces glued inside it hold up string tension and decide how it sounds.","answer":"An acoustic guitar is a wooden box. Thin spruce is glued into a top, braced inside, and joined to bent side walls and a back. A neck with metal frets is fitted, the body is finished, and a bridge, tuners and strings are added. The strings' vibration drives the top, and the box makes it loud.","aka":["steel-string guitar","classical guitar","flat-top guitar"],"inputs":["timber","adhesive","lacquer","steel-wire","nylon"],"uses":[],"grounds":["timber","water","crude-oil","corn","sugarcane","air","natural-gas","sulfur","rock-salt","iron-ore","limestone","dolomite","manganese-ore","coal","sugar-beet","quartz"],"upstreamSlugs":["timber","adhesive","lacquer","steel-wire","nylon","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","ethanol","steel","benzene","nitric-acid","ammonia","ethylene","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","crude-oil","hydrogen","corn","sugarcane","yeast","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","naphtha","toluene","air","natural-gas","sulfur","rock-salt","molasses","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","coal","sugar-beet","quartz","charcoal"],"downstreamSlugs":[],"steps":[{"name":"Season the tonewood","process":"dry","text":"Spruce for the top, and other woods for the back, sides and neck, are dried until stable. A luthier chooses wood by how it carries sound.","inputs":["timber"]},{"name":"Join the top and back","process":"laminate","text":"Two thin boards are matched edge to edge and glued to make each wide plate. Then the top gets its sound hole.","inputs":["adhesive"]},{"name":"Glue braces inside the top","process":"assemble","text":"A pattern of wood braces is glued under the top to resist the pull of the strings. Fan bracing, used by the Spanish maker Antonio Torres Jurado, first appeared on guitars in the late 18th century.","inputs":["adhesive"]},{"name":"Bend the sides","process":"mold","text":"Thin side strips are heated and bent around a form to the guitar's waisted outline.","inputs":[]},{"name":"Close the box","process":"assemble","text":"Sides, top and back are glued together around internal blocks and edge strips, forming the sound box.","inputs":["adhesive"]},{"name":"Shape the neck and set frets","process":"machine","text":"The neck is carved, a fingerboard is added, and metal fret wire is pressed into slots at precise spacing. A truss rod keeps the neck straight.","inputs":[]},{"name":"Spray the finish","process":"coat","text":"Thin layers of lacquer or varnish are sprayed on and polished. The body must stay free to vibrate, so makers keep the finish thin.","inputs":["lacquer"]},{"name":"Fit bridge, tuners and strings","process":"assemble","text":"The bridge is glued to the top, tuning machines go on the headstock, and strings are tensioned. Strings are steel or nylon.","inputs":["steel-wire","nylon"]}],"facts":["The C.F. Martin company introduced steel strings and a bigger top, and its large dreadnought body is linked to greater volume.","No sound is amplified by an acoustic guitar. The top just moves air more easily than a string can.","The Adamas model replaced the single sound hole with 22 small ones."],"where":[],"whereNote":null,"sources":[{"title":"Acoustic guitar","url":"https://en.wikipedia.org/wiki/Acoustic_guitar"},{"title":"Luthier","url":"https://en.wikipedia.org/wiki/Luthier"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"acrylic","name":"Acrylic","kind":"material","category":"plastics","title":"How acrylic sheet is made","url":"https://assemblyline.org/make/acrylic","stations":5,"upstream":11,"downstream":186,"depth":4,"dek":"Acrylic is the clear plastic sold as Plexiglas, and it was first marketed in 1933.","answer":"Acrylic is polymethyl methacrylate. Its monomer, methyl methacrylate, is made from petrochemicals and then polymerized. For clear sheet, a partly-reacted syrup is poured between two flat plates and cured in an oven. Pellets for extrusion and molding are made by running the same reaction in a continuous reactor.","aka":["PMMA","Plexiglas","Perspex","acrylic glass"],"inputs":["propylene","ammonia","sulfuric-acid","methanol"],"uses":["paint","adhesive","lcd-screen","sunglasses","lacquer","globe"],"grounds":["crude-oil","natural-gas","water","air","sulfur"],"upstreamSlugs":["propylene","ammonia","sulfuric-acid","methanol","naphtha","crude-oil","natural-gas","water","air","sulfur","hydrogen"],"downstreamSlugs":["paint","adhesive","lcd-screen","sunglasses","lacquer","globe","refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","scissors","mirror","car","electric-car","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","golf-ball","wallpaper","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","adhesive-bandage","credit-card","duct-tape","led-bulb","ev-battery","nail","insulation","popcorn","windshield","skateboard","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","door","pencil-eraser","clear-tape","staple","sofa","ski","snowboard","ice-skates","volleyball","cricket-bat","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","sailboat","dress-shirt","suit","raincoat","handbag","suitcase","wallet","flip-flops","hiking-boots","high-heels","smartwatch","wireless-earbuds","loudspeaker","microphone","camera-lens","e-reader","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","sneaker","leather-shoe","baseball-cap","carpet","mattress","diaper","laptop","television","digital-camera","tin-can","electric-guitar","trumpet","chopsticks","saxophone","felt-hat","vinyl-record","compact-disc","baseball-bat","padlock","dishwasher","treadmill","toothbrush","fireworks","plastic-wrap","trading-cards","cake-mix","soda","energy-drink","hair-dye","tampon","soap","toothpaste","deodorant","detergent","plastic-bag","nitrile-glove","vacuum-cleaner","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","blender","pillow","mouthwash","cough-syrup","light-switch","smoke-detector","game-console","wifi-router","remote-control","facial-tissue","condensed-milk","baby-formula","coconut-milk","canned-soup","aa-battery","candy-cane","syringe","toffee"],"steps":[{"name":"Build the monomer","process":"react","text":"Propylene and ammonia-derived chemicals are combined in a multistep route that ends with methyl methacrylate, a clear liquid. Sulfuric acid is used as a reagent along the way.","inputs":["propylene","ammonia","sulfuric-acid","methanol"]},{"name":"Make a thick syrup","process":"react","text":"The liquid is warmed with a small amount of initiator until it partly polymerizes into a syrupy mix. That makes the next step manageable.","inputs":[]},{"name":"Cast it between glass plates","process":"cast","text":"Syrup is poured into a cell made of two flat, polished plates sealed with a gasket. Those plates give the finished sheet its glossy, flawless face.","inputs":[]},{"name":"Cure it slowly in an oven","process":"dry","text":"Gentle heat over hours hardens the syrup into a solid sheet. Heating slowly keeps the plastic free of bubbles.","inputs":[]},{"name":"Pop the plates and trim","process":"cut","text":"The plates are separated from the clear sheet, which is then trimmed and covered in protective masking. Thin or continuous sheet is made by extrusion instead.","inputs":[]}],"facts":["During World War II, both Allied and Axis forces used acrylic glass for submarine periscopes and for aircraft windscreens, canopies and gun turrets.","Acrylic is also sold as Plexiglas, Perspex, Lucite and Acrylite.","British chemists Rowland Hill and John Crawford at ICI discovered poly(methyl methacrylate) in the early 1930s."],"where":[],"whereNote":null,"sources":[{"title":"Poly(methyl methacrylate)","url":"https://en.wikipedia.org/wiki/Poly%28methyl_methacrylate%29"},{"title":"Polymerization","url":"https://en.wikipedia.org/wiki/Polymerization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"acrylic-acid","name":"Acrylic acid","kind":"material","category":"chemicals","title":"How acrylic acid is made","url":"https://assemblyline.org/make/acrylic-acid","stations":6,"upstream":7,"downstream":3,"depth":4,"dek":"The stuff that lets a diaper swallow a flood begins as a sharp-smelling liquid made from propylene and air.","answer":"A two-stage oxidation of propylene gives this acrid, colorless liquid. Propylene, air and steam first form acrolein over a catalyst, and a second reactor takes that on to the acid. The hot gas is cooled and the product captured in water or a solvent. Extraction and distillation then finish it for diaper polymers, paints and adhesives.","aka":["propenoic acid","prop-2-enoic acid"],"inputs":["propylene","air"],"uses":["superabsorbent-polymer"],"grounds":["air","crude-oil","water","natural-gas"],"upstreamSlugs":["propylene","air","naphtha","crude-oil","water","hydrogen","natural-gas"],"downstreamSlugs":["superabsorbent-polymer","sanitary-pad","diaper"],"steps":[{"name":"Mix propylene, air and steam","process":"mix","text":"Steam does two jobs in this feed. The second-stage catalysis needs it, and it dilutes the gas away from an explosive mixture. Some designs recycle waste gas to replace part of it, because steam costs money and too much makes the product harder to recover.","inputs":["propylene","air"]},{"name":"Oxidize propylene to acrolein","process":"react","text":"The gas passes over a catalyst in the first reactor. Most of the propylene stops at acrolein, an acrid-smelling intermediate, with a little of the final product as a by-product. Hot spots in the catalyst bed are the danger here, so heat has to be kept under control.","inputs":[]},{"name":"Send acrolein onward","process":"react","text":"Outlet gas from the first stage goes straight into a second reactor with nothing separated out. A different catalyst carries the acrolein the rest of the way. Some designs add fresh oxygen or steam at this point.","inputs":[]},{"name":"Cool and capture the vapor","process":"separate","text":"The product leaves as a gas. Cooling condenses it into a water solution, or a suitable solvent absorbs it instead.","inputs":[]},{"name":"Recycle the leftover gas","process":"separate","text":"What remains is mostly nitrogen, carbon dioxide and carbon monoxide, with some unreacted propylene and acrolein. Part of it can go back to the reactors as a diluent.","inputs":[]},{"name":"Extract and distill","process":"refine","text":"Purification uses extraction, distillation or similar steps to isolate the product from its water solution. Then polymer makers take over. Diaper plants blend it with sodium hydroxide and polymerize it into sodium polyacrylate.","inputs":[]}],"facts":["Chemists coined the word acrylic in 1843, naming a derivative of acrolein.","Acrylic acid is the simplest unsaturated carboxylic acid.","More than a million tons of acrylic acid are produced each year."],"where":[],"whereNote":null,"sources":[{"title":"Acrylic acid","url":"https://en.wikipedia.org/wiki/Acrylic_acid"},{"title":"Superabsorbent polymer","url":"https://en.wikipedia.org/wiki/Superabsorbent_polymer"},{"title":"US4873368A, Process for producing acrylic acid","url":"https://patents.google.com/patent/US4873368"},{"title":"US4365087A, Production of acrylic acid","url":"https://patents.google.com/patent/US4365087A/en"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"action-figure","name":"Action figure","kind":"product","category":"play","title":"How action figures are made","url":"https://assemblyline.org/make/action-figure","stations":7,"upstream":71,"downstream":0,"depth":10,"dek":"Every joint on a Mattel action figure has to survive a 20-pound pull during testing.","answer":"An artist sculpts the figure, and a factory scans the approved sculpt and builds a steel mold from it. Molten plastic is injected into the mold, usually in two main colors. The parts are checked, details such as eyes and buttons are painted through masks or by pad, and the pieces are snapped or welded together and boxed.","aka":["collectible figure","toy figure","poseable figure"],"inputs":["abs-plastic","pvc","nylon","paint","screw"],"uses":[],"grounds":["air","water","crude-oil","natural-gas","iron-ore","sulfur","rock-salt","titanium-ore","zinc-ore","coal","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","limestone","dolomite","manganese-ore","quartz","timber","sugar-beet"],"upstreamSlugs":["abs-plastic","pvc","nylon","paint","screw","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","chlorine","water","plasticizer","nitric-acid","titanium-dioxide","acrylic","tin-can","steel-wire","zinc","crude-oil","hydrogen","natural-gas","toluene","iron-ore","carbon-black","sulfur","rock-salt","sulfuric-acid","titanium-ore","coke","oxygen","methanol","tinplate","lacquer","ink","steel","zinc-ore","coal","tin","ethanol","vegetable-oil","phenolic-resin","pig-iron","magnesium","steel-scrap","lime","manganese","argon","tin-ore","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","limestone","dolomite","silicon","propane","manganese-ore","molasses","quartz","charcoal","timber","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Sculpt the master","process":"machine","text":"A sculptor starts from a sketch and works through several rounds of art-directed sculpts. Hair and faces may be sculpted by hand or on a computer.","inputs":[]},{"name":"Scan and test-paint it","process":"inspect","text":"The factory takes a 3D scan of the sculpt and runs revisions until the product team is happy. A final prototype is then painted to show what the finished toy should look like.","inputs":[]},{"name":"Build the injection mold","process":"machine","text":"The factory builds a massive steel mold, compared by one maker to a giant ice cube tray. A mold for just one or two heads can measure about 16 inches on a side, and each lasts a year or two.","inputs":[]},{"name":"Inject the plastic","process":"mold","text":"A machine flash-injects molten plastic into the mold. Typically two main colors go in, one for skin and one for the outfit. Harder plastics such as ABS make bodies and softer PVC makes rubbery parts. A production mold cycles in about a minute.","inputs":["abs-plastic","pvc","nylon"]},{"name":"Check the molded parts","process":"inspect","text":"After the plastic cools, pins pop the parts out of the mold, and they are inspected for quality.","inputs":[]},{"name":"Paint the fine details","process":"coat","text":"Copper spray masks, which work like stencils and must be cleaned every 10 uses, lay down color. Tampo machines add printed detail, and each layer has to be aligned by hand. Paint wiped over a sculpt fills the recesses in hair.","inputs":["paint"]},{"name":"Assemble and box","process":"assemble","text":"Workers put the figure together by hand with snaps and screws, and sonic welding uses vibration to melt some parts together. Joints get a pull test, and the figure goes into a snug custom box.","inputs":["screw"]}],"facts":["Hasbro coined the term action figure in 1964 to sell G.I. Joe to boys who refused to play with dolls.","The little indented circles sometimes seen on a figure are marks left by the pins that pop it out of the mold.","Tin soldiers were made in Germany as early as the 1730s by casting metal between two slabs of slate."],"where":[],"whereNote":null,"sources":[{"title":"Action figure","url":"https://en.wikipedia.org/wiki/Action_figure"},{"title":"How We Make Our Action Figures","url":"https://shop.fctry.com/blogs/blog/how-action-figures-get-made-part-1-design-1"},{"title":"C2E2 Mattel Panel","url":"https://www.oafe.net/blog/2011/03/c2e2-mattel-panel/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"adhesive","name":"Adhesive","kind":"material","category":"chemicals","title":"How adhesives are made","url":"https://assemblyline.org/make/adhesive","stations":8,"upstream":26,"downstream":135,"depth":7,"dek":"Neanderthals made glue from birch bark about 200,000 years ago, and every glue since works by sticking or by reacting.","answer":"Hot-melt adhesive is made in big jacketed kettles or sigma-blade mixers. Tackifiers and waxes melt first, then thick polymers go in over several additions, along with additives. A sample goes to the lab, and approved batches are pumped out to be filled. Water-based glues disperse the polymer in water instead, while reactive epoxies and polyurethanes are sold as separate parts.","aka":["glue","hot melt","epoxy glue"],"inputs":["polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water"],"uses":["adhesive-bandage","credit-card","duct-tape","led-bulb","ev-battery","pencil","nail","insulation","popcorn","windshield","skateboard","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","pencil-eraser","clear-tape","staple","sofa","ski","snowboard","ice-skates","golf-club","fishing-rod","volleyball","cricket-bat","dartboard","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","globe","snow-globe","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","brake-pad","sailboat","dress-shirt","suit","raincoat","handbag","suitcase","wallet","flip-flops","hiking-boots","high-heels","smartwatch","wireless-earbuds","loudspeaker","microphone","camera-lens","e-reader","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","sneaker","leather-shoe","baseball-cap","carpet","mattress","diaper"],"grounds":["water","crude-oil","natural-gas","air","sulfur","rock-salt","coal"],"upstreamSlugs":["polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","naphtha","natural-gas","air","sulfur","benzene","rock-salt","toluene","coal"],"downstreamSlugs":["adhesive-bandage","credit-card","duct-tape","led-bulb","ev-battery","pencil","nail","insulation","popcorn","windshield","skateboard","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","pencil-eraser","clear-tape","staple","sofa","ski","snowboard","ice-skates","golf-club","fishing-rod","volleyball","cricket-bat","dartboard","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","globe","snow-globe","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","brake-pad","sailboat","dress-shirt","suit","raincoat","handbag","suitcase","wallet","flip-flops","hiking-boots","high-heels","smartwatch","wireless-earbuds","loudspeaker","microphone","camera-lens","e-reader","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","sneaker","leather-shoe","baseball-cap","carpet","mattress","diaper","electric-car","dishwasher","car","aluminum-window-frame","digital-camera","shipping-container","ceiling-fan","treadmill","toothbrush","fireworks","plastic-wrap","trading-cards","cake-mix","soda","energy-drink","hair-dye","tampon","soap","toothpaste","deodorant","detergent","plastic-bag","nitrile-glove","washing-machine","vacuum-cleaner","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","blender","pillow","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","game-console","wifi-router","remote-control","facial-tissue","aa-battery","candy-cane","syringe"],"steps":[{"name":"Choose the base polymer","process":"react","text":"Makers start from polymers such as polyethylene, polyacrylates, polyurethanes and epoxies, picked to suit the job. Reactive types stay as separate parts that harden only when combined.","inputs":["polyethylene","acrylic","epoxy","polyurethane"]},{"name":"Melt in a heated kettle","process":"melt","text":"The heavy steel kettle warms to mixing temperature, and the thin ingredients, tackifiers and waxes or oils, melt first. One patent preheats its kettle to about 350 degrees Fahrenheit.","inputs":["paraffin-wax"]},{"name":"Feed in thick polymers","process":"mix","text":"Polymers and elastomers go in over several additions. A vertical kettle has a mixer emulsifier, a high-speed blade and an anchor agitator that scrapes the wall to keep the adhesive from degrading in the heat.","inputs":[]},{"name":"Shear in sigma blades","process":"mix","text":"Some plants use a horizontal mixer instead, with two large sigma-shaped blades running toward each other at different speeds in a curved trough. The tight gap at the wall shears the mix.","inputs":[]},{"name":"Extrude it continuously","process":"extrude","text":"Pressure-sensitive hot-melts are often made continuously in an extruder rather than in batches.","inputs":[]},{"name":"Thin with water","process":"mix","text":"For water-based and solvent-based glues, the mix is emulsified in water or dissolved in a solvent. When the liquid evaporates, a sticky polymer film stays behind.","inputs":["water"]},{"name":"Sample for quality control","process":"inspect","text":"A sample is drawn from the kettle for testing. Only a batch that meets the specification gets pumped onward.","inputs":[]},{"name":"Mold, chill and pack","process":"fill","text":"One patent pumps molten hot-melt into molds, chills them, empties out the solid blocks, dusts them and sends them to packaging.","inputs":[]}],"facts":["About 6,000 years ago, people in one burial site repaired broken clay pots with tree resin.","Adhesives are classed as reactive or non-reactive, depending on whether they harden by a chemical reaction."],"where":[],"whereNote":null,"sources":[{"title":"US5852083A, Process for making hot melt adhesives","url":"https://patents.google.com/patent/US5852083/en"},{"title":"US6006497A, Methods and apparatus for preparing a hot melt adhesive","url":"https://patents.google.com/patent/US6006497/en"},{"title":"Adhesive","url":"https://en.wikipedia.org/wiki/Adhesive"},{"title":"Epoxy","url":"https://en.wikipedia.org/wiki/Epoxy"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"adhesive-bandage","name":"Adhesive bandage","kind":"product","category":"body-health","title":"How adhesive bandages are made","url":"https://assemblyline.org/make/adhesive-bandage","stations":7,"upstream":40,"downstream":0,"depth":8,"dek":"The first Band-Aids were handmade strips 18 inches long, and they earned just $3,000 in 1921.","answer":"Bandages are converted from rolls. Patents describe a web of fabric or polyurethane film laminated to adhesive and siliconized release paper. The layers are peeled apart so the paper can be scored and a center wound layer laid down, then rejoined and sent between a die roll and an anvil roll that cuts out each shape. Sterile versions are packaged and irradiated with gamma rays.","aka":["Band-Aid","sticking plaster","plaster"],"inputs":["adhesive","paper","cotton-fabric","polyurethane"],"uses":[],"grounds":["water","kaolin","limestone","crude-oil","timber","raw-cotton","corn","air","rock-salt","natural-gas","sulfur","coal"],"upstreamSlugs":["adhesive","paper","cotton-fabric","polyurethane","polyethylene","acrylic","epoxy","paraffin-wax","water","wood-pulp","kaolin","limestone","cotton-yarn","corn-starch","propylene","nitric-acid","chlorine","ethylene","ammonia","sulfuric-acid","methanol","phenol","acetone","caustic-soda","crude-oil","hydrogen","timber","lime","oxygen","hydrogen-peroxide","raw-cotton","corn","naphtha","air","rock-salt","natural-gas","sulfur","benzene","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Roll-coat the adhesive","process":"coat","text":"A roller spreads solvent-based acrylic adhesive across release paper that has been siliconized on one side. The solvent evaporates and leaves a tacky layer.","inputs":["adhesive","paper"]},{"name":"Laminate to the carrier","process":"laminate","text":"The coated paper is pressed against the carrier strip, a fabric or a polyurethane film about 35 μm thick in one example, and the stack is slit to width and wound into a feedstock roll.","inputs":["cotton-fabric","polyurethane"]},{"name":"Separate and score","process":"cut","text":"Driven rolls pull the stack apart. The release strip runs between an embossing roll and an anvil roll, which scores it down the middle so a user can peel it off later.","inputs":[]},{"name":"Lay down the center","process":"coat","text":"A wound layer goes on the middle of the strip, leaving the adhesive edges clear. One patent feeds a non-stick gel from a hollow needle, while other designs use an absorbent pad of folded nonwoven.","inputs":[]},{"name":"Relaminate the stack","process":"laminate","text":"The scored release strip returns to its old position on the bandage strip and covers the center layer, which keeps the wound side untouched from here on.","inputs":[]},{"name":"Die-cut each shape","process":"cut","text":"The stack passes between a die roll and an anvil. The cut goes through the bandage strip and not the paper, and corners are rounded here. Delaminating rolls then lift away the waste skeleton.","inputs":[]},{"name":"Package and irradiate","process":"package","text":"Strips are cut apart and sealed into wrappers. For a sterile product the sealed packs are treated with gamma rays, and the wrapper keeps them clean until opened.","inputs":["paper"]}],"facts":["Earle Dickson invented the Band-Aid in 1920 for his wife Josephine, who often cut and burned herself cooking.","Machine-made Band-Aids arrived in 1924, and sterilized ones went on sale in 1939."],"where":[],"whereNote":null,"sources":[{"title":"US4867821A: Process for fabricating self-adhesive bandages","url":"https://patents.google.com/patent/US4867821"},{"title":"US4619253A: Foil- or film-like bandage and process for using the same","url":"https://patents.google.com/patent/US4619253"},{"title":"Adhesive bandage","url":"https://en.wikipedia.org/wiki/Adhesive_bandage"},{"title":"Band-Aid","url":"https://en.wikipedia.org/wiki/Band-Aid"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"air","name":"Air","kind":"raw","category":"ground","title":"How air is collected and separated","url":"https://assemblyline.org/make/air","stations":4,"upstream":0,"downstream":516,"depth":0,"dek":"Air is 78% nitrogen, and factories split it apart by cooling it until it turns to liquid.","answer":"Industry takes air from the atmosphere by the millions of cubic meters. It is filtered, compressed, scrubbed of water and carbon dioxide, and chilled until it liquefies. In a tall distillation column, nitrogen, oxygen and argon boil off at different temperatures and are drawn off as separate gases.","aka":["atmosphere","compressed air"],"inputs":[],"uses":["penicillin","insulin","vaccine","vitamin-c","sulfuric-acid","nitric-acid","ammonia","nitrogen","oxygen","abs-plastic","carbon-black","carbon-fiber","pig-iron","copper","zinc","chromium","basketball","soccer-ball","zinc-oxide","argon","phenol","hydrogen-peroxide","formaldehyde","neon","acrylic-acid","plasticizer","acetone","mercury"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["penicillin","insulin","vaccine","vitamin-c","sulfuric-acid","nitric-acid","ammonia","nitrogen","oxygen","abs-plastic","carbon-black","carbon-fiber","pig-iron","copper","zinc","chromium","basketball","soccer-ball","zinc-oxide","argon","phenol","hydrogen-peroxide","formaldehyde","neon","acrylic-acid","plasticizer","acetone","mercury","flour","shampoo","nail-polish","aspirin","detergent","fertilizer","chlorine","acrylic","ptfe","kevlar","titanium-dioxide","lithium-carbonate","nickel","silver","cobalt","manganese","phosphoric-acid","refrigerant","indium","germanium","car-battery","vanadium","rayon","acetaminophen","nylon","polyurethane","platinum","iridium","soda-ash","led","baking-soda","caramel-color","hair-dye","melamine-resin","polyvinylpyrrolidone","polysilicon","memory-chip","window-glass","light-bulb","potato-chips","beef-jerky","office-chair","fire-extinguisher","microchip","steel","stainless-steel","optical-fiber","rocket","steel-scrap","polyvinyl-alcohol","ethylene-glycol","wood-pulp","lipstick","hearing-aid","thermometer","lego-brick","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","ballpoint-pen","snowboard","action-figure","harmonica","globe","suitcase","high-heels","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","mascara","rubber","ink","aa-battery","tire","hockey-puck","tungsten-carbide","printer-toner","hiking-boots","rubber-boots","vinyl-record","pigment","wind-turbine","drone","satellite","airplane","bicycle","tennis-racket","golf-club","fishing-rod","kite","prosthetic-leg","cast-iron-pan","car-engine","piano","dumbbell","sailboat","printed-circuit-board","lithium-ion-cell","ev-battery","camera-sensor","solar-panel","refrigerator","microwave-oven","copper-wire","brass","bronze","solder","faucet","padlock","coin","gold-ring","air-conditioner","flute","toy-car","medal","bell","stained-glass","light-switch","power-outlet","brake-pad","spark-plug","jeans","sunscreen","sheet-steel","rebar","lead","gold","neodymium-magnet","nail","screw","steel-pipe","staple","bolt","barbed-wire","chain-link-fence","suspension-bridge-cable","hip-implant","hard-drive","safety-pin","razor-blade","turbine-blade","toaster","ice-skates","stent","wrench","nichrome","leather","foundation-makeup","ferrite","silicon-wafer","titanium","double-glazed-window","neon-sign","polycarbonate","epoxy","billiard-ball","phenolic-resin","silk","towel","super-glue","spandex","superabsorbent-polymer","pvc","pvb","yoga-mat","hairspray","vinyl-floor","cellulose-acetate","shoelace","eyeglass-frame","bread","instant-noodles","tortilla","croissant","donut","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","fish-sticks","modeling-clay","licorice","cake-mix","bleach","nitrile-glove","hydrochloric-acid","paint","adhesive","lcd-screen","sunglasses","lacquer","nonstick-pan","raincoat","canoe","toothpaste","crayon","pencil-eraser","candy-coated-chocolate","pvc-pipe","needle","jet-engine","trumpet","key","compact-disc","solar-cell","mirror","thermos","saxophone","smoke-detector","cola","soda","asthma-inhaler","indium-tin-oxide","tampon","toothbrush","airbag","guitar","violin","bike-helmet","velcro","dishwasher","roller-skates","volleyball","fashion-doll","ukulele","drumstick","eyeshadow","dental-floss","aluminum-window-frame","underwear","leggings","swimsuit","down-jacket","handbag","backpack","flag","socks","carpet","zipper","rope","adhesive-bandage","pacemaker","car","skateboard","surfboard","golf-ball","hardwood-floor","water-heater","sofa","bowling-ball","wheelchair","sneaker","mattress","fiberglass","glass","glass-bottle","smartphone-glass","marble-toy","led-bulb","pinball-machine","sparkling-water","rum","laminate-floor","smartphone","solid-state-drive","smartwatch","digital-camera","skyscraper","windshield","credit-card","electric-car","electric-motor","transformer","vacuum-cleaner","wristwatch","tinplate","steel-wire","steel-beam","rail","scissors","ball-bearing","container-ship","shipping-container","locomotive","motorcycle","elevator","drum-kit","wine-barrel","ski","yo-yo","hammer","drill-bit","gas-cylinder","seat-belt","subway-train","leather-belt","loudspeaker","syringe","washing-machine","electric-kettle","kitchen-knife","fork","fountain-pen","water-bottle","pressure-cooker","blender","banknote","pet-plastic","kitchen-sponge","sanitary-pad","paper","cardboard","toilet-paper","facial-tissue","diaper","pencil","tennis-ball","baseball","football","cricket-bat","treadmill","ladder","wheelbarrow","leather-shoe","umbrella","plastic-bag","tin-can","aluminum-can","paper-cup","pizza-box","wallpaper","marker-pen","highlighter","frisbee","board-game","jigsaw-puzzle","trading-cards","floor-tile","flip-flops","cardboard-box","newspaper","book","sticky-notes","playing-cards","t-shirt","saw-blade","porcelain","chalk","candy-cane","sprinkles","plastic-straw","ceiling-fan","electric-guitar","power-cable","microphone","garden-hose","guitar-string","hinge","bronze-statue","shovel","concrete","chess-set","gold-bar","winter-gloves","wallet","eyeglass-lens","camera-lens","photoresist","silk-tie","plastic-wrap","inflatable-pool-toy","dice","deodorant","silicone","trichlorosilane","wooden-chair","dartboard","snow-globe","coil-spring","duct-tape","insulation","popcorn","paper-straw","paper-bag","door","clear-tape","cello","cotton-swab","roof-shingle","dress-shirt","suit","plywood","mdf","envelope","match","baseball-cap","chopsticks","felt-hat","baseball-bat","oled-screen","glass-jar","perfume","ketchup","beer","wine","champagne","whiskey","vodka","gin","tequila","sake","hard-cider","hot-sauce","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","port-wine","prosecco","non-alcoholic-beer","canned-tuna","air-freshener","wire-rope","paperclip","clothespin","slinky","chain","polyester","plastic-bottle","bottled-water","soap","drywall","fireworks","egg-carton","energy-drink","cotton-candy","pillow","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","light-beer","insect-repellent","corn-flakes","candle","salsa","zip-bag","mouthwash","cough-syrup","condom","contact-lens","cork-stopper","mustard","pickles","sauerkraut","jam","hazelnut-spread","dish-soap","wet-wipes","hoodie","curtain","button","thread","teddy-bear","toffee","mayonnaise","blanket","sweater"],"steps":[{"name":"Filter and compress","process":"separate","text":"Air is filtered for dust and then compressed. Typical pressures run between 5 and 10 bar gauge, and the compression supplies the energy that later drives refrigeration.","inputs":[],"spec":"5 to 10 bar gauge"},{"name":"Scrub out water and CO2","process":"separate","text":"The compressed air passes through a bed of molecular sieve. It traps water vapor and carbon dioxide, which would freeze solid and plug the cold equipment.","inputs":[]},{"name":"Chill it to liquid","process":"chill","text":"Inside an insulated enclosure called a cold box, the air is cooled against the cold product streams until part of it liquefies. It is a delicate balance of heat exchangers and columns.","inputs":[]},{"name":"Distill the gases apart","process":"refine","text":"Nitrogen boils at 77.4 K, argon at 87.3 K and oxygen at 90.2 K, so the columns peel them off in order. Argon builds up in the middle of the low-pressure column, where a side draw collects it.","inputs":[]}],"facts":["Dry air is 78.08% nitrogen, 20.95% oxygen, 0.93% argon and 0.04% carbon dioxide by mole fraction.","Carl von Linde developed the cryogenic process in 1895, and it stayed purely academic for seven years before its first industrial use in 1902.","Neon, krypton and xenon can only be got by distilling air in at least two columns."],"where":[],"whereNote":null,"sources":[{"title":"Atmosphere of Earth","url":"https://en.wikipedia.org/wiki/Atmosphere_of_Earth"},{"title":"Air separation","url":"https://en.wikipedia.org/wiki/Air_separation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"air-conditioner","name":"Air conditioner","kind":"product","category":"machines","title":"How air conditioners are made","url":"https://assemblyline.org/make/air-conditioner","stations":6,"upstream":65,"downstream":0,"depth":8,"dek":"An air conditioner moves heat around a copper loop that is leak-tested and dried before any refrigerant goes in.","answer":"Copper tubes are bent into hairpins and threaded through stacks of thin aluminum fins to make the coils. The joints are brazed, leak-tested with pressurized gas, and dried. The coils join a compressor, fan and sheet-metal case, the loop is emptied of air, and a measured charge of refrigerant is added.","aka":["AC","air conditioning unit","split system"],"inputs":["copper","aluminum","solder","sheet-steel","electric-motor","refrigerant"],"uses":[],"grounds":["copper-ore","water","air","crude-oil","coal","fluorspar","sulfur","bauxite","tin-ore","lead-ore","silver-ore","zinc-ore","rock-salt","natural-gas","corn","limestone","iron-ore","dolomite","manganese-ore","quartz","timber","sugarcane","sugar-beet"],"upstreamSlugs":["copper","aluminum","solder","sheet-steel","electric-motor","refrigerant","copper-ore","water","oxygen","air","sulfuric-acid","crude-oil","coal","petroleum-coke","alumina","tin","lead","silver","steel","zinc","copper-wire","epoxy","ball-bearing","fluorspar","chlorine","ammonia","carbon-dioxide","propane","sulfur","bauxite","caustic-soda","lime","tin-ore","coke","lead-ore","silver-ore","zinc-ore","pig-iron","magnesium","steel-scrap","manganese","argon","phenol","propylene","acetone","steel-wire","rock-salt","natural-gas","corn","yeast","limestone","iron-ore","dolomite","silicon","manganese-ore","benzene","naphtha","molasses","quartz","charcoal","timber","hydrogen","toluene","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Bend the copper hairpins","process":"forge","text":"Straight lengths of copper tube are bent into U-shaped hairpins. They will carry refrigerant through the coil.","inputs":["copper"]},{"name":"Stamp the aluminum fins","process":"stamp","text":"Thin aluminum sheet is stamped into fins with holes for the tubes. Hundreds of fins stack up so air can touch a huge surface.","inputs":["aluminum"]},{"name":"Lace tubes through fins","process":"assemble","text":"Hairpins are pushed through the stack of fins. The tubes are then expanded so they grip the fins tightly.","inputs":[]},{"name":"Braze and leak-test","process":"weld","text":"Torches and filler metal join tube ends and headers. Gas under pressure then checks the coil for leaks before it is dried.","inputs":["solder"]},{"name":"Assemble the unit","process":"assemble","text":"The coils go into a painted sheet-metal case with a compressor, fan motors and controls.","inputs":["sheet-steel","electric-motor"]},{"name":"Evacuate and charge","process":"fill","text":"A vacuum pump pulls moisture and air out of the sealed loop, and a charging machine adds the right amount of refrigerant.","inputs":["refrigerant"]}],"facts":["In 1820 Michael Faraday found that compressing and liquefying ammonia, then letting it evaporate, chilled the air around it.","Willis Carrier designed what is widely regarded as the first modern electrical air-conditioning system in 1902, for a Brooklyn printing plant that needed its paper to hold still."],"where":[],"whereNote":null,"sources":[{"title":"Air conditioning","url":"https://en.wikipedia.org/wiki/Air_conditioning"},{"title":"Method for manufacturing a heat transfer coil","url":"https://patents.google.com/patent/US5644841"},{"title":"Air Conditioning Systems: Design, Manufacturing, and Future Trends","url":"https://www.mfgrobots.com/Article/mfg/mpm/2376.html"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"air-freshener","name":"Air freshener","kind":"product","category":"body-health","title":"How air fresheners are made","url":"https://assemblyline.org/make/air-freshener","stations":5,"upstream":48,"downstream":0,"depth":7,"dek":"The spray can in an air freshener was first a military design for dispensing insecticide.","answer":"An aerosol air freshener is a metal can holding a fragrance concentrate and a liquefied propellant gas under pressure. The can is filled, a valve is crimped onto its rim, and a pressing button opens the valve so the mix leaves as a fine mist. Other types use wicks, gels or heated plug-ins.","aka":["room spray","odor eliminator","plug-in freshener"],"inputs":["perfume","ethanol","tinplate","propane"],"uses":[],"grounds":["oranges","vanilla-pods","water","corn","sugarcane","natural-gas","crude-oil","silica-sand","limestone","tin-ore","rock-salt","trona","sugar-beet","iron-ore","air","dolomite","manganese-ore","coal","quartz","timber","sulfur"],"upstreamSlugs":["perfume","ethanol","tinplate","propane","oranges","vanilla-pods","water","glass-bottle","corn","sugarcane","yeast","ethylene","steel","tin","natural-gas","crude-oil","silica-sand","soda-ash","limestone","polyethylene","molasses","naphtha","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","tin-ore","coke","rock-salt","ammonia","carbon-dioxide","trona","sugar-beet","hydrogen","iron-ore","air","dolomite","silicon","manganese-ore","sulfuric-acid","coal","quartz","charcoal","timber","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Blend the fragrance","process":"mix","text":"Perfume oils are mixed with solvents and often with ingredients that bond or absorb odors. Some products add surfactants, preservatives or disinfectants.","inputs":["perfume","ethanol"]},{"name":"Fill the can","process":"fill","text":"The concentrate goes into a can made of lacquered tinplate, steel with a layer of tin, or of aluminum for premium products.","inputs":["tinplate"]},{"name":"Crimp on the valve","process":"assemble","text":"A valve is crimped to the inside rim of the can. Its design determines the spray rate, and a spring closes it again when the button is released.","inputs":[]},{"name":"Charge with propellant","process":"fill","text":"A propellant that is a gas at room temperature, but turns liquid under modest pressure, is forced in. Modern cans use mixtures of propane, butane and isobutane. Propellant filling machines must be installed outside the main production building, in a gas house.","inputs":["propane"]},{"name":"Fit the button","process":"assemble","text":"The actuator is fitted over the valve. Its nozzle controls the size of the droplets and how wide the spray spreads.","inputs":[]}],"facts":["Air Wick launched in the United States in 1939 as a liquid that evaporated up a wick.","Commercial aerosol sprays arrived in 1948, from a military technology for dispensing insecticide.","CFC propellants were abandoned because they damaged the ozone layer, and the Montreal Protocol came into force in 1989."],"where":[],"whereNote":null,"sources":[{"title":"Air freshener","url":"https://en.wikipedia.org/wiki/Air_freshener"},{"title":"Aerosol spray","url":"https://en.wikipedia.org/wiki/Aerosol_spray"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"airbag","name":"Airbag","kind":"product","category":"machines","title":"How airbags are made","url":"https://assemblyline.org/make/airbag","stations":8,"upstream":85,"downstream":2,"depth":9,"dek":"An airbag has to unfold completely in about 20 to 30 milliseconds, which is faster than a blink.","answer":"An airbag is a nylon fabric cushion that is sewn, folded and sealed into a module together with a gas inflator. Panels of woven nylon are cut and sewn into a bag. Specialist plants make the inflator. A crash sensor wired to the module signals it to fire, and the bag inflates in a few hundredths of a second.","aka":["air bag","supplemental restraint system","inflatable restraint"],"inputs":["nylon","silicone","thread","sheet-steel","printed-circuit-board","microchip"],"uses":["car","electric-car"],"grounds":["water","silica-sand","air","natural-gas","quartz","coal","timber","zinc-ore","copper-ore","limestone","tin-ore","crude-oil","gold-ore","rock-salt","iron-ore","dolomite","manganese-ore","sulfur","trona","lead-ore","silver-ore","bauxite","corn","sugarcane","sugar-beet"],"upstreamSlugs":["nylon","silicone","thread","sheet-steel","printed-circuit-board","microchip","benzene","nitric-acid","ammonia","silicon","methanol","hydrochloric-acid","water","silica-sand","polyester","steel","zinc","copper","fiberglass","epoxy","photoresist","solder","silicon-wafer","oxygen","tin","aluminum","gold","naphtha","hydrogen","toluene","air","natural-gas","quartz","coke","coal","charcoal","timber","chlorine","pet-plastic","pig-iron","magnesium","steel-scrap","lime","manganese","argon","zinc-ore","sulfuric-acid","copper-ore","limestone","soda-ash","phenol","propylene","acetone","caustic-soda","phenolic-resin","lead","silver","polysilicon","tin-ore","crude-oil","petroleum-coke","alumina","gold-ore","rock-salt","p-xylene","ethylene","ethylene-glycol","iron-ore","dolomite","propane","manganese-ore","sulfur","carbon-dioxide","trona","formaldehyde","lead-ore","silver-ore","trichlorosilane","nitrogen","bauxite","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["car","electric-car"],"steps":[{"name":"Weave the nylon cloth","process":"weave","text":"Tough nylon yarn is woven into a tight, strong fabric. A loose weave would leak the gas, and a weak one would tear.","inputs":["nylon"]},{"name":"Seal the fabric with a coating","process":"coat","text":"Some bag designs get a thin coating of silicone to hold in hot gas and protect the fabric.","inputs":["silicone"]},{"name":"Cut the cushion panels","process":"cut","text":"Cutting machines slice stacks of fabric into circles and shaped panels, one pattern for each type of bag.","inputs":[]},{"name":"Stitch the bag","process":"sew","text":"Panels are sewn along their seams with strong thread, often in more than one pass. Some designs have several chambers.","inputs":["thread"]},{"name":"Fold into a tight pack","process":"assemble","text":"The finished cushion is folded in a precise pattern so it unfolds in the right direction, and it is compressed into a small cover.","inputs":[]},{"name":"Seal it onto the inflator","process":"assemble","text":"Inflators are made in specialist plants under strict controls. Here the folded bag and the sealed inflator are fixed into a metal housing, which will sit behind a trim cover in the wheel or dash.","inputs":["sheet-steel"]},{"name":"Link the sensors and controller","process":"assemble","text":"The module is wired to a control unit, which reads accelerometers and other sensors. It decides in an instant whether a crash is severe enough to fire the bag.","inputs":["printed-circuit-board","microchip"]},{"name":"Test modules at random","process":"inspect","text":"Samples from each batch are deployed in a test cell, and the bag is checked for speed, shape and leaks.","inputs":[]}],"facts":["Airbags inflate in approximately 20 to 30 milliseconds, so the bag is full before the forward-moving occupant reaches it.","Research in the 1960s showed that compressed air could not fill a bag fast enough, which led to chemical inflators."],"where":[],"whereNote":null,"sources":[{"title":"Airbag","url":"https://en.wikipedia.org/wiki/Airbag"},{"title":"Car","url":"https://en.wikipedia.org/wiki/Car"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"airplane","name":"Airliner","kind":"product","category":"machines","title":"How airliners are made","url":"https://assemblyline.org/make/airplane","stations":9,"upstream":100,"downstream":0,"depth":10,"dek":"The Boeing 787 was the first airliner with an airframe made mostly of composite, and its wings flexed 25 feet in testing.","answer":"An airliner is built in sections, often in different countries. Wings, fuselage barrels, tail and doors are shaped from aluminum, titanium and carbon-fiber composite, then shipped to a final assembly hall. There the sections are joined, engines hung, wiring and cabin fitted, and the whole aircraft is painted, tested and flown before delivery.","aka":["jetliner","passenger jet","commercial aircraft","Boeing 787"],"inputs":["aluminum","titanium","carbon-fiber","epoxy","steel","jet-engine","copper-wire","printed-circuit-board","paint","jet-fuel"],"uses":[],"grounds":["crude-oil","coal","titanium-ore","air","water","bauxite","rock-salt","dolomite","natural-gas","iron-ore","limestone","manganese-ore","nickel-ore","copper-ore","silica-sand","sulfur","quartz","timber","clay","kaolin","feldspar","cobalt-ore","chromite","trona","tin-ore","lead-ore","silver-ore","zinc-ore","corn","sugarcane","soybeans","rapeseed","sugar-beet"],"upstreamSlugs":["aluminum","titanium","carbon-fiber","epoxy","steel","jet-engine","copper-wire","printed-circuit-board","paint","jet-fuel","crude-oil","coal","petroleum-coke","alumina","titanium-ore","chlorine","magnesium","argon","propylene","ammonia","air","phenol","acetone","caustic-soda","pig-iron","steel-scrap","oxygen","lime","manganese","nickel","turbine-blade","copper","fiberglass","photoresist","solder","water","titanium-dioxide","pigment","acrylic","tin-can","hydrogen","bauxite","rock-salt","sulfuric-acid","dolomite","silicon","naphtha","natural-gas","benzene","iron-ore","coke","limestone","propane","manganese-ore","nickel-ore","paraffin-wax","ceramic","cobalt","chromium","copper-ore","silica-sand","soda-ash","phenolic-resin","tin","lead","silver","carbon-black","sulfur","methanol","tinplate","lacquer","ink","quartz","charcoal","timber","toluene","clay","kaolin","feldspar","cobalt-ore","chromite","carbon-dioxide","trona","formaldehyde","tin-ore","lead-ore","zinc","silver-ore","zinc-ore","ethanol","vegetable-oil","corn","yeast","sugarcane","ethylene","soybeans","rapeseed","hexane","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Shape the metal skin and frames","process":"machine","text":"Aluminum sheet and plate are cut, milled and formed into skin panels, ribs and frames. Landing gear and wing fittings are machined from titanium and steel.","inputs":["aluminum","titanium"]},{"name":"Lay up the composite sections","process":"laminate","text":"On a 787, much of the airframe is carbon-fiber composite, built up in layers around a form. The airliner was the first with an airframe made mostly of composite materials.","inputs":["carbon-fiber","epoxy"]},{"name":"Cure the layers hard","process":"bake","text":"Heat and pressure harden the resin so the layers bond into a single solid shell, light and stiff.","inputs":[]},{"name":"Forge the landing gear","process":"forge","text":"Heavy steel and titanium forgings take the shock of landing, then are machined to final shape and finished.","inputs":["steel","titanium"]},{"name":"Join the big sections","process":"assemble","text":"Fuselage sections, wings and tail arrive from plants around the world and are fastened together in a final assembly hall. The 787's fuselage sections came from Italy, Japan, South Korea and the US.","inputs":[]},{"name":"Hang the engines","process":"assemble","text":"Each engine is lifted on a pylon under the wing, and fuel lines, electrics and controls are hooked up.","inputs":["jet-engine"]},{"name":"Wire and fit the cabin","process":"assemble","text":"Kilometers of wiring are laid through the body before panels, galleys, lavatories and seats go in.","inputs":["copper-wire","printed-circuit-board"]},{"name":"Paint the livery","process":"coat","text":"The airplane is sanded, primed, painted in the airline's colors and sealed with clear coat.","inputs":["paint"]},{"name":"Test, then fly","process":"inspect","text":"A test airframe is pressurized past service limits, and wings are bent upward before the real flight tests begin. The 787's test fuselage held a pressure difference of 14.9 psi, 150 percent of what it should meet in service.","inputs":["jet-fuel"]}],"facts":["Composites can conduct as little as 1/1,000th as much electricity as aluminum, so conductive material is added to cope with lightning strikes.","Japanese companies co-designed and built 35 percent of the 787."],"where":[],"whereNote":null,"sources":[{"title":"Airliner","url":"https://en.wikipedia.org/wiki/Airliner"},{"title":"Boeing 787 Dreamliner","url":"https://en.wikipedia.org/wiki/Boeing_787_Dreamliner"},{"title":"Aircraft fuselage","url":"https://en.wikipedia.org/wiki/Aircraft_fuselage"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"almond-milk","name":"Almond milk","kind":"product","category":"food","title":"How almond milk is made","url":"https://assemblyline.org/make/almond-milk","stations":6,"upstream":2,"downstream":0,"depth":1,"dek":"Almond milk is mostly water. One US lawsuit noted that some cartons held only 2 percent almonds.","answer":"Almonds are soaked and ground in a large amount of water. The milky liquid is filtered from the pulp, then flavored and fortified with vitamins. For stability and shelf life a commercial plant homogenizes it at high pressure and pasteurizes it before filling cartons.","aka":["almond drink","almond beverage"],"inputs":["almonds","water"],"uses":[],"grounds":["almonds","water"],"upstreamSlugs":["almonds","water"],"downstreamSlugs":[],"steps":[{"name":"Soak the nuts","process":"mix","text":"Almonds are soaked in water to soften them before grinding.","inputs":["almonds"]},{"name":"Grind with extra water","process":"crush","text":"The soaked almonds are ground in a large excess of water, which releases oil and protein from the nut into a milky white suspension.","inputs":["water"]},{"name":"Filter out the pulp","process":"separate","text":"The mixture passes through a filter that holds back the almond pulp and lets the white liquid through.","inputs":[]},{"name":"Add flavor and vitamins","process":"mix","text":"Commercial almond milk is usually fortified with micronutrients, since the nut itself delivers few of the vitamins found in dairy milk. Sweetener and vanilla or chocolate flavor may be added.","inputs":[]},{"name":"Homogenize under pressure","process":"mix","text":"High pressure breaks up the oil droplets so the drink does not separate in the carton.","inputs":[]},{"name":"Pasteurize and fill","process":"pasteurize","text":"Heat treatment gives the drink its shelf life before it is filled and sealed.","inputs":[]}],"facts":["The oldest known almond milk recipes date to 1226 in a cookbook from the Middle East.","In 2013 almond milk passed soy milk as the most popular plant milk in the United States.","One glass of almond milk takes about 74 liters of water to produce, mostly for growing the nuts."],"where":[],"whereNote":null,"sources":[{"title":"Almond milk","url":"https://en.wikipedia.org/wiki/Almond_milk"},{"title":"Oat milk","url":"https://en.wikipedia.org/wiki/Oat_milk"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"almonds","name":"Almonds","kind":"raw","category":"farm","title":"How almonds are grown","url":"https://assemblyline.org/make/almonds","stations":4,"upstream":0,"downstream":2,"depth":0,"dek":"An almond is the seed of a stone fruit, and most trees need pollen from a different variety.","answer":"Almonds are the seeds inside a leathery-hulled fruit related to the peach. Orchards grow two or more varieties together, because common almond trees cannot pollinate themselves, and insects carry the pollen between them. California supplies about 80 percent of the world's almonds.","aka":["almond","sweet almond","almond nuts"],"inputs":[],"uses":["almond-milk","toffee"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["almond-milk","toffee"],"steps":[{"name":"Plant mixed varieties","process":"grow","text":"The most widely planted almonds are self-incompatible, so orchards alternate rows of two or more varieties. The trees need a Mediterranean-style climate with dry summers.","inputs":[]},{"name":"Bring in the bees","process":"grow","text":"White-pink blossoms open before the leaves in early spring. Growers must make sure enough insects visit, because the pollen has to move from tree to tree.","inputs":[]},{"name":"Collect the ripe nuts","process":"harvest","text":"At harvest the fruit has become a dry drupe with a leathery grey-green hull around a hard shell. Nuts are separated from hulls and shells.","inputs":[]},{"name":"Hull, shell and sort","process":"separate","text":"Machines crack the shell to free the seed, and some are blanched in hot water to loosen the brown skin. Cleaned almonds keep for a long time in storage.","inputs":[]}],"facts":["The almond is not a true nut but the seed of a drupe, like a peach pit.","Almond buds need 200 to 700 hours below 7.2 °C before they will break dormancy.","Bitter almonds release cyanide when crushed with water, so they are not eaten raw."],"where":[{"place":"California","share":"about 80% of world supply"}],"whereNote":"Share of the world almond supply, per Wikipedia.","sources":[{"title":"Almond","url":"https://en.wikipedia.org/wiki/Almond"},{"title":"Almond milk","url":"https://en.wikipedia.org/wiki/Almond_milk"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"alumina","name":"Alumina","kind":"material","category":"metals","title":"How alumina is made","url":"https://assemblyline.org/make/alumina","stations":6,"upstream":6,"downstream":160,"depth":2,"dek":"Alumina is white aluminum oxide pulled out of red bauxite with hot caustic soda, and the red leftovers stay behind.","answer":"Alumina is refined from bauxite by the Bayer process. Crushed ore is cooked under pressure with a hot sodium hydroxide solution, which dissolves the aluminum and leaves iron-rich red residue behind. The clear liquid is cooled and seeded so aluminum hydroxide crystals grow, and a kiln at about 1,200 °C then bakes the crystals into dry alumina powder.","aka":["aluminum oxide","Bayer process","refined bauxite"],"inputs":["bauxite","caustic-soda","lime","water"],"uses":["aluminum","smartphone-glass","laminate-floor","spark-plug"],"grounds":["bauxite","water","rock-salt","limestone"],"upstreamSlugs":["bauxite","caustic-soda","lime","water","rock-salt","limestone"],"downstreamSlugs":["aluminum","smartphone-glass","laminate-floor","spark-plug","deodorant","lipstick","microchip","led-bulb","oled-screen","lithium-ion-cell","ev-battery","smartphone","laptop","hard-drive","solid-state-drive","solar-cell","solar-panel","refrigerator","washing-machine","satellite","pencil","aluminum-foil","brass","cobalt","chromium","nonstick-pan","aluminum-can","mirror","skyscraper","car","electric-car","car-engine","airplane","rocket","bicycle","motorcycle","skateboard","drum-kit","pencil-eraser","pressure-cooker","toaster","air-conditioner","ceiling-fan","office-chair","ski","yo-yo","toy-car","eyeshadow","asthma-inhaler","prosthetic-leg","wheelchair","ladder","double-glazed-window","aluminum-window-frame","subway-train","sailboat","suitcase","smartwatch","microphone","camera-lens","vinyl-record","compact-disc","game-console","graphics-card","vanadium","newspaper","zipper","n95-mask","hearing-aid","pacemaker","thermometer","credit-card","television","computer-keyboard","computer-mouse","drone","airbag","wireless-earbuds","phone-charger","usb-cable","digital-camera","wifi-router","e-reader","inkjet-printer","remote-control","electric-toothbrush","toothpaste","aspirin","condom","aa-battery","wristwatch","faucet","padlock","tire","electric-guitar","trumpet","ballpoint-pen","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","light-switch","power-outlet","leather-belt","handbag","flag","hip-implant","turbine-blade","tungsten-carbide","stent","stainless-steel","safety-pin","razor-blade","ice-skates","dumbbell","wrench","nichrome","leather","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","locomotive","down-jacket","raincoat","backpack","jeans","jet-engine","saw-blade","syringe","electric-kettle","kitchen-knife","fork","elevator","thermos","water-bottle","blender","dishwasher","golf-club","baseball","basketball","tennis-racket","football","winter-gloves","wallet","hiking-boots","high-heels","leather-shoe"],"steps":[{"name":"Grind the bauxite","process":"crush","text":"Bauxite contains only 30 to 60 percent aluminum oxide, with the rest a mix of silica, iron oxides and titanium dioxide. It is ground so the hot liquor can reach the aluminum minerals.","inputs":["bauxite"]},{"name":"Digest it in hot caustic","process":"react","text":"The ground bauxite is heated in a pressure vessel with a strong sodium hydroxide solution. The aluminum dissolves as sodium aluminate. Silica dissolves too, and lime is sometimes added to help knock the silica back out.","inputs":["caustic-soda","lime"],"spec":"150 to 200 °C"},{"name":"Filter out the red mud","process":"separate","text":"What does not dissolve, mostly iron oxide, silica and titania, is filtered from the liquid with the help of a flocculant such as starch. This residue is called bauxite tailings, or red mud.","inputs":[]},{"name":"Seed the liquor to crystallize","process":"react","text":"The clear solution is cooled and fine crystals of aluminum hydroxide are added as seeds. New crystals grow on them. Without seeds, precipitation can take several days.","inputs":[]},{"name":"Wash and filter the crystals","process":"wash","text":"The aluminum hydroxide is separated from the liquor, which is recycled to digest more bauxite. Recycling lets gallium and vanadium build up in the liquor until they are worth extracting.","inputs":["water"]},{"name":"Bake it in a kiln","process":"fire","text":"About 90 percent of the aluminum hydroxide goes into a rotary kiln or flash calciner heated to around 1,200 °C. The water leaves and fine white alumina powder remains.","inputs":[],"spec":"about 1,200 °C"}],"facts":["The Bayer process is also the main source of the metal gallium, as a byproduct.","Some of the aluminum hydroxide never goes to the kiln, and is used for water-treatment chemicals and as a fire-retardant filler in rubber and plastics.","Red mud dries into a fine powder of iron, aluminum, calcium and sodium, and refiners keep looking for uses for it. Ceramics is one."],"where":[],"whereNote":null,"sources":[{"title":"Bayer process","url":"https://en.wikipedia.org/wiki/Bayer_process"},{"title":"Aluminium","url":"https://en.wikipedia.org/wiki/Aluminium"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"aluminum","name":"Aluminum","kind":"material","category":"metals","title":"How aluminum is made","url":"https://assemblyline.org/make/aluminum","stations":5,"upstream":10,"downstream":156,"depth":3,"dek":"Aluminum is made by running a huge electric current through molten salt, and the metal sinks to the bottom.","answer":"Aluminum is made by electrolysis. Alumina powder is dissolved in a bath of molten cryolite at 940 to 980 °C, and a direct current of 100 to 300 kiloamperes runs between carbon anodes and the cell floor. Liquid metal collects at the bottom, is siphoned out every day or two, and is cast into ingots.","aka":["aluminium","primary aluminum","Hall-Heroult process"],"inputs":["crude-oil","coal","petroleum-coke","alumina"],"uses":["deodorant","lipstick","microchip","led-bulb","oled-screen","lithium-ion-cell","ev-battery","smartphone","laptop","hard-drive","solid-state-drive","solar-cell","solar-panel","refrigerator","washing-machine","satellite","pencil","aluminum-foil","brass","cobalt","chromium","nonstick-pan","aluminum-can","mirror","skyscraper","car","electric-car","car-engine","airplane","rocket","bicycle","motorcycle","skateboard","drum-kit","pencil-eraser","pressure-cooker","toaster","air-conditioner","ceiling-fan","office-chair","ski","yo-yo","toy-car","eyeshadow","asthma-inhaler","prosthetic-leg","wheelchair","ladder","double-glazed-window","aluminum-window-frame","subway-train","sailboat","suitcase","smartwatch","microphone","camera-lens","vinyl-record","compact-disc","game-console","graphics-card","vanadium","newspaper","zipper","n95-mask"],"grounds":["crude-oil","coal","bauxite","water","rock-salt","limestone"],"upstreamSlugs":["crude-oil","coal","petroleum-coke","alumina","bauxite","caustic-soda","lime","water","rock-salt","limestone"],"downstreamSlugs":["deodorant","lipstick","microchip","led-bulb","oled-screen","lithium-ion-cell","ev-battery","smartphone","laptop","hard-drive","solid-state-drive","solar-cell","solar-panel","refrigerator","washing-machine","satellite","pencil","aluminum-foil","brass","cobalt","chromium","nonstick-pan","aluminum-can","mirror","skyscraper","car","electric-car","car-engine","airplane","rocket","bicycle","motorcycle","skateboard","drum-kit","pencil-eraser","pressure-cooker","toaster","air-conditioner","ceiling-fan","office-chair","ski","yo-yo","toy-car","eyeshadow","asthma-inhaler","prosthetic-leg","wheelchair","ladder","double-glazed-window","aluminum-window-frame","subway-train","sailboat","suitcase","smartwatch","microphone","camera-lens","vinyl-record","compact-disc","game-console","graphics-card","vanadium","newspaper","zipper","n95-mask","hearing-aid","pacemaker","thermometer","credit-card","television","computer-keyboard","computer-mouse","drone","airbag","wireless-earbuds","phone-charger","usb-cable","digital-camera","wifi-router","e-reader","inkjet-printer","remote-control","electric-toothbrush","toothpaste","aspirin","condom","aa-battery","wristwatch","faucet","padlock","tire","electric-guitar","trumpet","ballpoint-pen","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","light-switch","power-outlet","leather-belt","handbag","flag","hip-implant","turbine-blade","tungsten-carbide","stent","stainless-steel","safety-pin","razor-blade","ice-skates","dumbbell","wrench","nichrome","leather","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","locomotive","down-jacket","raincoat","backpack","jeans","jet-engine","saw-blade","syringe","electric-kettle","kitchen-knife","fork","elevator","thermos","water-bottle","blender","dishwasher","golf-club","baseball","basketball","tennis-racket","football","winter-gloves","wallet","hiking-boots","high-heels","leather-shoe"],"steps":[{"name":"Bake the carbon anodes","process":"bake","text":"Petroleum coke, the solid left over from refining crude oil, is bound with pitch from coal tar and baked in big gas-fired ovens into carbon blocks. These are the anodes, and they are used up in the reaction, so smelters must make them continuously.","inputs":["crude-oil","coal","petroleum-coke"]},{"name":"Dissolve alumina in cryolite","process":"melt","text":"Alumina melts at 2072 °C, far too hot to be practical. So it is dissolved in molten cryolite, a sodium aluminum fluoride that melts near 1000 °C, with some aluminum fluoride added to lower the temperature further.","inputs":["alumina"],"spec":"940 to 980 °C"},{"name":"Run the current through the pot","process":"electrolyze","text":"A low direct-current voltage, under 5 volts, but at 100 to 300 kiloamperes, runs through the bath. Oxygen from the alumina burns the carbon anode away to carbon dioxide, and aluminum is deposited on the cell floor. Pots run around the clock so the bath never freezes.","inputs":[],"spec":"about 15.37 kWh per kilogram"},{"name":"Siphon off the metal","process":"separate","text":"Liquid aluminum is denser than the molten bath, so it sinks and pools at the bottom. It is siphoned out every 1 to 3 days, which avoids hot-metal valves and pumps. Fresh alumina is fed in to replace what was used.","inputs":["alumina"]},{"name":"Alloy and cast","process":"cast","text":"The metal goes to a holding furnace, where other metals such as magnesium, manganese, copper, zinc or silicon are added for strength, and then is cast into ingots, billets or slabs.","inputs":[]}],"facts":["Recycling aluminum takes only 5 percent of the energy of making it from ore.","Cells in a smelter run 24 hours a day, because if the molten bath were left to cool it would solidify.","Iceland has no notable bauxite, yet it ranks among the larger aluminum producers because its hydropower is cheap and plentiful."],"where":[{"place":"China","share":"over 55% of world output"},{"place":"India","share":"among the five largest producers"},{"place":"Russia","share":"among the five largest producers"},{"place":"Canada","share":"among the five largest producers"},{"place":"United Arab Emirates","share":"among the five largest producers"}],"whereNote":"2024, primary aluminum production.","sources":[{"title":"Hall–Héroult process","url":"https://en.wikipedia.org/wiki/Hall%E2%80%93H%C3%A9roult_process"},{"title":"Aluminium","url":"https://en.wikipedia.org/wiki/Aluminium"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"aluminum-can","name":"Aluminum can","kind":"product","category":"hardware","title":"How aluminum cans are made","url":"https://assemblyline.org/make/aluminum-can","stations":6,"upstream":47,"downstream":12,"depth":8,"dek":"A soda can is squeezed out of a flat disc, and its walls end up about as thin as a sheet of paper.","answer":"An aluminum drink can begins as a punched disc of stiff sheet aluminum. A press forms the disc into a short cup, and then rams push the cup through a series of rings that stretch and thin the sides. The body is trimmed, washed, printed, lined and necked in before a lid is seamed on.","aka":["beverage can","soda can","drink can"],"inputs":["aluminum","ink","epoxy"],"uses":["deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent"],"grounds":["crude-oil","coal","water","bauxite","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","limestone","natural-gas","sugar-beet"],"upstreamSlugs":["aluminum","ink","epoxy","crude-oil","coal","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","phenol","propylene","acetone","chlorine","caustic-soda","bauxite","lime","soybeans","rapeseed","hexane","clay","formaldehyde","air","titanium-ore","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","ethylene","benzene","naphtha","rock-salt","limestone","hydrogen","methanol","molasses","natural-gas","toluene","sugar-beet"],"downstreamSlugs":["deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent"],"steps":[{"name":"Punch out discs","process":"stamp","text":"A press blanks flat circles from a coil of stiff aluminum alloy that contains about 1 percent each of manganese and magnesium for strength.","inputs":["aluminum"]},{"name":"Cup the disc","process":"stamp","text":"The first draw turns the flat blank into a shallow cup about three inches across.","inputs":[]},{"name":"Iron the walls","process":"press","text":"A ram pushes the cup through a series of tight rings. Each ring stretches the wall taller and thinner, and the bottom is domed in the same stroke. The side ends up thinner than the top and bottom, where stiffness is needed.","inputs":[]},{"name":"Trim and wash","process":"wash","text":"The ragged top edge is cut off straight, and the can is washed clean of lubricant.","inputs":[]},{"name":"Print the label","process":"print","text":"A rotating printer rolls the design around the can in a single pass.","inputs":["ink"]},{"name":"Line and neck in","process":"coat","text":"A plastic liner is sprayed inside to keep the drink from touching the metal. The top is then narrowed to make room for a smaller lid.","inputs":["epoxy"]}],"facts":["Beer first went on sale in cans in 1935, in Richmond, Virginia.","Coors introduced the recyclable aluminum can in 1959.","Aluminum makes up 75% of the world's drink can production."],"where":[],"whereNote":null,"sources":[{"title":"Beverage can","url":"https://en.wikipedia.org/wiki/Beverage_can"},{"title":"Deep drawing","url":"https://en.wikipedia.org/wiki/Deep_drawing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"aluminum-foil","name":"Aluminum foil","kind":"product","category":"metals","title":"How aluminum foil is made","url":"https://assemblyline.org/make/aluminum-foil","stations":5,"upstream":11,"downstream":4,"depth":4,"dek":"That shiny side and dull side are an accident of rolling two sheets together at once.","answer":"Aluminum foil starts as a thick aluminum sheet that is rolled again and again, cold, until it is a fraction of a millimeter thick. In the final pass two sheets are rolled at once, then peeled apart. The sides that touched are matte, and the sides that met the polished rollers come out shiny.","aka":["tin foil","aluminium foil","kitchen foil"],"inputs":["aluminum"],"uses":["toothpaste","aspirin","condom","usb-cable"],"grounds":["crude-oil","coal","bauxite","water","rock-salt","limestone"],"upstreamSlugs":["aluminum","crude-oil","coal","petroleum-coke","alumina","bauxite","caustic-soda","lime","water","rock-salt","limestone"],"downstreamSlugs":["toothpaste","aspirin","condom","usb-cable"],"steps":[{"name":"Cast a thick sheet","process":"cast","text":"Molten aluminum is poured through a continuous caster to make a sheet, in a way that uses less energy than the older route of casting ingots. This is the strip that will be thinned.","inputs":["aluminum"]},{"name":"Roll it down in steps","process":"roll","text":"The sheet is cold-rolled through mills that shrink its thickness with every pass. Foil is an alloy of 92 to 99 percent aluminum.","inputs":[]},{"name":"Double up for the last pass","process":"roll","text":"The rollers cannot get close enough together to produce the thinnest foil, and a single sheet that thin tears. So for gauges below 0.025 millimeters, two sheets are rolled together, doubling the thickness entering the rolls.","inputs":[]},{"name":"Peel the pair apart","process":"separate","text":"After the rolls, the two layers are separated. The sides that pressed against each other are matte, and the outer sides that touched the polished rolls are shiny. The difference does not matter in cooking.","inputs":[]},{"name":"Slit and wind","process":"cut","text":"Circular or razor-like knives trim and slit the foil to width, and it is wound into rolls. Standard household foil is about 0.016 millimeters thick.","inputs":[]}],"facts":["The first aluminum foil rolling plant opened in 1910 in Emmishofen, Switzerland.","Tobler began wrapping its chocolate in aluminum foil in 1911, including the triangular Toblerone bar.","Foil sparks in a microwave oven, because the fields drive currents through it and voltage builds at sharp points until it arcs through the air."],"where":[],"whereNote":null,"sources":[{"title":"Aluminium foil","url":"https://en.wikipedia.org/wiki/Aluminium_foil"},{"title":"Cold rolling","url":"https://en.wikipedia.org/wiki/Cold_rolling"},{"title":"Aluminium","url":"https://en.wikipedia.org/wiki/Aluminium"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ladder","name":"Aluminum ladder","kind":"product","category":"hardware","title":"How aluminum ladders are made","url":"https://assemblyline.org/make/ladder","stations":7,"upstream":24,"downstream":0,"depth":8,"dek":"A ladder's rails are squeezed out of an aluminum billet like toothpaste.","answer":"A cast aluminum billet is preheated and forced through a shaped die to give a long I-beam rail, which is quenched and aged for strength. Holes are punched along the web, and the metal around each is stamped into an embossment with a rung-shaped opening. Extruded tube rungs get a swaged shoulder, pass through the openings, and are swaged again on the far side to lock them in place.","aka":["step ladder","extension ladder"],"inputs":["aluminum","rubber"],"uses":[],"grounds":["crude-oil","coal","natural-latex","sulfur","bauxite","water","air","rock-salt","limestone","natural-gas"],"upstreamSlugs":["aluminum","rubber","crude-oil","coal","petroleum-coke","alumina","natural-latex","synthetic-rubber","carbon-black","sulfur","bauxite","caustic-soda","lime","water","naphtha","benzene","ethylene","styrene","air","rock-salt","limestone","hydrogen","toluene","natural-gas"],"downstreamSlugs":[],"steps":[{"name":"Extrude the rails","process":"extrude","text":"A billet cut to working length is preheated to about 500 °C and pushed through a die, and emerges with the rail's cross section along its full length.","inputs":["aluminum"]},{"name":"Harden and age","process":"heat-treat","text":"Profiles are cooled quickly to harden, then aged at 160 to 170 °C for 10 to 12 hours to set their mechanical strength.","inputs":[]},{"name":"Punch and emboss the web","process":"stamp","text":"The web of each rail is drilled or punched with evenly spaced pilot holes, and the metal around each hole is pressed out to one side to form an embossment.","inputs":[]},{"name":"Stamp the rung openings","process":"stamp","text":"Each embossment's flat center is stamped into an opening matching the rung's shape, so the rung fits snugly.","inputs":[]},{"name":"Swage the rung shoulders","process":"press","text":"Rungs of extruded aluminum tube are swaged at each end to raise a double-walled shoulder, set back from the end edge.","inputs":["aluminum"]},{"name":"Lock the rungs in","process":"assemble","text":"Rung ends pass through the openings until the shoulders stop against the inner face. A last swage flares the tips over the outer face, gripping the rail from both sides.","inputs":[]},{"name":"Fit feet and spreaders","process":"assemble","text":"Rubber feet and any folding spreaders go on the finished frame.","inputs":["rubber"]}],"facts":["The vertical sides of a ladder are called rails in the United States and stiles in the United Kingdom.","In a chicken ladder, a single central stile carries rungs that stick out on each side."],"where":[],"whereNote":null,"sources":[{"title":"US patent 4205426: Method of fabricating metal ladder","url":"https://patents.google.com/patent/US4205426"},{"title":"Virastar: How aluminum profile for ladders is made","url":"https://virastar.ua/en/blog/yak-vigotovlyayut-alyuminiyeviy-profil-dlya-drabin"},{"title":"Ladder","url":"https://en.wikipedia.org/wiki/Ladder"},{"title":"Extrusion","url":"https://en.wikipedia.org/wiki/Extrusion"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"aluminum-window-frame","name":"Aluminum window frame","kind":"product","category":"metals","title":"How aluminum window frames are made","url":"https://assemblyline.org/make/aluminum-window-frame","stations":9,"upstream":83,"downstream":0,"depth":10,"dek":"Aluminum carries heat so well that window frames are split in two and rejoined by a plastic strip.","answer":"Heated aluminum billets are forced through steel dies into long profiles, which are aged and then powder coated or anodized. To stop heat crossing, wheels knurl and crimp inner and outer profiles onto a polyamide strip. Saws then miter the pieces at 45 degrees, corner cleats lock them into a rigid rectangle, and a glass unit goes in.","aka":["aluminium window","window profile"],"inputs":["aluminum","paint","nylon","double-glazed-window"],"uses":[],"grounds":["crude-oil","coal","water","bauxite","titanium-ore","iron-ore","sulfur","air","natural-gas","silica-sand","limestone","dolomite","rock-salt","trona","tin-ore","quartz","timber","corn","sugarcane","soybeans","rapeseed","clay","manganese-ore","sugar-beet"],"upstreamSlugs":["aluminum","paint","nylon","double-glazed-window","crude-oil","coal","petroleum-coke","alumina","water","titanium-dioxide","pigment","acrylic","tin-can","benzene","nitric-acid","ammonia","window-glass","adhesive","argon","silicone","bauxite","caustic-soda","lime","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","carbon-black","sulfur","propylene","methanol","tinplate","lacquer","ink","naphtha","hydrogen","toluene","air","natural-gas","silica-sand","soda-ash","limestone","dolomite","tin","nitrogen","polyethylene","epoxy","polyurethane","paraffin-wax","silicon","hydrochloric-acid","rock-salt","steel","ethanol","vegetable-oil","phenolic-resin","carbon-dioxide","trona","tin-ore","ethylene","phenol","acetone","quartz","charcoal","timber","pig-iron","magnesium","steel-scrap","manganese","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","formaldehyde","propane","manganese-ore","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Extrude the profile","process":"extrude","text":"Aluminum logs are cut and preheated until malleable, then forced through a precision steel die under hydraulic pressure. Long hollow sections come out the other side, usually in 6063 or 6060 alloy.","inputs":["aluminum"],"spec":"750 to 970°F, 800 to 2500 tons"},{"name":"Age for strength","process":"heat-treat","text":"The profiles get a T5 heat treatment to strengthen them before any finish goes on.","inputs":[]},{"name":"Coat the surface","process":"coat","text":"Dry powder is sprayed on electrostatically and cured under heat, typically to 60 to 120 micrometers. Anodizing is the costlier alternative, thickening the metal's own oxide in an acid bath.","inputs":["paint"],"spec":"60 to 120 micrometers"},{"name":"Knurl the pockets","process":"press","text":"A knurling wheel cuts tiny teeth, 0.15 to 0.30 mm long, into a pocket on the inner and outer profiles. Later they will bite into the strip.","inputs":[]},{"name":"Insert the polyamide strip","process":"assemble","text":"Special equipment feeds a rigid polyamide strip into the pockets. It joins the two pieces of metal and keeps heat from passing straight between them.","inputs":["nylon"]},{"name":"Crimp the assembly","process":"press","text":"Three sets of wheels roll the metal onto the strip, applying over 1300 pounds of pressure in stages. The result carries load as one composite, and samples are shear tested now and then.","inputs":[]},{"name":"Miter the lengths","process":"cut","text":"Saws cut the composite profile to length, with each end at 45 degrees.","inputs":[]},{"name":"Cleat the corners","process":"assemble","text":"A corner cleat of aluminum or steel slides into the hollow chambers of two neighboring pieces and is fixed with screws, crimping or adhesive.","inputs":["aluminum"]},{"name":"Set the glass","process":"assemble","text":"A sealed glass unit is set into the finished rectangle against compressed gaskets.","inputs":["double-glazed-window"]}],"facts":["An anodized layer can crack but will not peel, unlike a coat of paint.","A rival thermal break is made by pouring liquid polymer into a channel in the extrusion, letting it harden, then cutting away the metal under it."],"where":[],"whereNote":null,"sources":[{"title":"Extrusion","url":"https://en.wikipedia.org/wiki/Extrusion"},{"title":"Anodizing","url":"https://en.wikipedia.org/wiki/Anodizing"},{"title":"Aluminum Extrusion Assemblies Provide a Thermal Barrier, Aluminum Extruders Council","url":"https://aec.org/thermal-barrier"},{"title":"A Guide to Powder Coated Aluminium Windows Frame, HTS","url":"https://hts-alu.com/powder-coated-aluminium-windows-frame/"},{"title":"Extruded Aluminum Window Framing, Lucent Doors","url":"https://www.lucentdoors.com/post/extruded-aluminum-window-framing-engineering-guide"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"football","name":"American football","kind":"product","category":"play","title":"How American footballs are made","url":"https://assemblyline.org/make/football","stations":7,"upstream":53,"downstream":0,"depth":8,"dek":"An NFL football is sewn inside out and turned right side out by hand, after a steam bath to soften the leather.","answer":"A football starts as four matched panels cut from a cowhide. The panels are stamped, then sewn into two halves and joined inside out so the stitches hide inside. Workers steam the ball and turn it right side out by hand, fit an air bladder, lace it, and inflate it in a mold.","aka":["pigskin","gridiron football","NFL football"],"inputs":["leather","thread","rubber","pvc"],"uses":[],"grounds":["cattle-hide","rock-salt","water","natural-latex","sulfur","limestone","chromite","air","crude-oil","natural-gas","iron-ore","coal","trona","titanium-ore","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["leather","thread","rubber","pvc","cattle-hide","rock-salt","water","lime","chromium","polyester","natural-latex","synthetic-rubber","carbon-black","sulfur","ethylene","chlorine","pigment","plasticizer","limestone","chromite","coke","soda-ash","air","aluminum","pet-plastic","naphtha","benzene","styrene","crude-oil","natural-gas","sulfuric-acid","iron-ore","titanium-dioxide","propylene","coal","ammonia","carbon-dioxide","trona","petroleum-coke","alumina","p-xylene","ethylene-glycol","hydrogen","toluene","titanium-ore","oxygen","corn","yeast","bauxite","caustic-soda","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut four matched panels","process":"cut","text":"Each cowhide yields 40 to 50 panels, which is enough for 10 to 12 footballs at four panels each. The cutter's hardest job is matching the color of the four panels. Once matched, they stay together to the end.","inputs":["leather"]},{"name":"Stamp the logos","process":"stamp","text":"Heated heads press the panels. The first, at about 500 degrees Fahrenheit, flattens the pebbly grain to make a smooth surface, and the rest stamp metallic foil lettering. Decals are printed and laminated in house.","inputs":[]},{"name":"Sew it inside out","process":"sew","text":"Workers sew the top two panels together and the bottom two together. The halves are then sewn to each other inside out, so the stitches end up hidden once the ball is turned.","inputs":["thread"]},{"name":"Steam and turn it","process":"assemble","text":"The ball goes into a steam box for 30 seconds to soften the leather, and a worker turns it right side out by hand. This is hard and physical, and the best turners finish a ball in less than a minute. A press then rounds the ends.","inputs":[]},{"name":"Fit the air bladder","process":"assemble","text":"An air bladder goes inside the ball and the valve stem is trimmed.","inputs":["rubber"]},{"name":"Lace it by hand","process":"sew","text":"Workers pull the laces through the holes with an awl. NFL balls use latigo laces, made of PVC extruded leather, and college balls use laces with a pebbled grip.","inputs":["pvc"]},{"name":"Inflate it in a mold","process":"mold","text":"The football sits in a mold while it is blown up to 120 PSI to set its shape. The air is then let out down to 13 PSI before the ball is inspected for flaws in the leather, stitching and stamping.","inputs":[],"spec":"120 PSI in the mold"}],"facts":["Footballs are called pigskin, but the cover is cow leather.","Horween Leather Company has been the exclusive supplier of leather for NFL footballs since 1941.","Wilson has made leather game footballs in Ada, Ohio since 1955."],"where":[],"whereNote":null,"sources":[{"title":"How NFL Footballs are Made","url":"https://www.wilson.com/blogs/blog/how-nfl-footballs-are-made"},{"title":"Football (American football ball)","url":"https://en.wikipedia.org/wiki/American_football_(ball)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ammonia","name":"Ammonia","kind":"material","category":"chemicals","title":"How ammonia is made","url":"https://assemblyline.org/make/ammonia","stations":6,"upstream":3,"downstream":346,"depth":1,"dek":"Ammonia plants make fertilizer out of air and natural gas, and that feeds about half the people alive.","answer":"Ammonia is made by combining nitrogen from the air with hydrogen from natural gas over an iron catalyst at high pressure and heat. Only a fraction of the gas reacts on each pass. The ammonia is chilled into a liquid and drained off, and the unreacted gas is sent around the loop again.","aka":["NH3","Haber-Bosch process","anhydrous ammonia"],"inputs":["natural-gas","water","air"],"uses":["soda-ash","nitric-acid","fertilizer","abs-plastic","nylon","acrylic","carbon-fiber","kevlar","led","platinum","baking-soda","caramel-color","refrigerant","hair-dye","melamine-resin","iridium","polyvinylpyrrolidone"],"grounds":["natural-gas","water","air"],"upstreamSlugs":["natural-gas","water","air"],"downstreamSlugs":["soda-ash","nitric-acid","fertilizer","abs-plastic","nylon","acrylic","carbon-fiber","kevlar","led","platinum","baking-soda","caramel-color","refrigerant","hair-dye","melamine-resin","iridium","polyvinylpyrrolidone","detergent","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","instant-noodles","stained-glass","vanadium","nail-polish","acetaminophen","polyurethane","lipstick","hearing-aid","thermometer","lego-brick","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","ballpoint-pen","snowboard","action-figure","harmonica","globe","suitcase","high-heels","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","toothbrush","mascara","drone","tire","airbag","guitar","violin","basketball","bike-helmet","velcro","dishwasher","office-chair","roller-skates","tennis-racket","volleyball","kite","fashion-doll","ukulele","drumstick","eyeshadow","dental-floss","aluminum-window-frame","underwear","leggings","swimsuit","down-jacket","raincoat","handbag","backpack","hiking-boots","flag","socks","carpet","zipper","rope","paint","adhesive","lcd-screen","sunglasses","lacquer","wind-turbine","satellite","airplane","bicycle","golf-club","fishing-rod","prosthetic-leg","brake-pad","canoe","led-bulb","pinball-machine","hard-drive","pretzel","sparkling-water","frozen-pizza","bagel","crackers","cake-mix","fire-extinguisher","cola","rum","soda","refrigerator","air-conditioner","asthma-inhaler","laminate-floor","hairspray","printed-circuit-board","surfboard","ski","roof-shingle","vinyl-floor","sailboat","umbrella","lithium-ion-cell","hip-implant","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather","oled-screen","camera-sensor","solar-panel","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","floor-tile","neon-sign","smartwatch","mirror","skyscraper","windshield","double-glazed-window","perfume","penicillin","insulin","vaccine","ketchup","beer","wine","champagne","whiskey","vodka","gin","tequila","sake","hard-cider","hot-sauce","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","port-wine","prosecco","non-alcoholic-beer","smartphone","adhesive-bandage","pacemaker","car","skateboard","golf-ball","soccer-ball","hardwood-floor","sofa","wheelchair","sneaker","mattress","electric-car","motorcycle","jeans","washing-machine","electric-kettle","pencil","scissors","container-ship","shipping-container","locomotive","wallpaper","wooden-chair","water-bottle","ceiling-fan","billiard-ball","dartboard","dice","toy-car","coil-spring","hammer","wheelbarrow","gas-cylinder","suspension-bridge-cable","subway-train","leather-belt","eyeglass-frame","credit-card","duct-tape","ev-battery","nail","insulation","popcorn","piano","drum-kit","tennis-ball","baseball","paper-straw","paper-bag","pizza-box","door","pencil-eraser","clear-tape","staple","cricket-bat","chess-set","board-game","jigsaw-puzzle","cello","kitchen-sponge","sanitary-pad","cotton-swab","dress-shirt","suit","wallet","flip-flops","loudspeaker","microphone","camera-lens","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","leather-shoe","baseball-cap","diaper","digital-camera","tin-can","electric-guitar","trumpet","chopsticks","saxophone","felt-hat","vinyl-record","compact-disc","baseball-bat","solid-state-drive","rocket","elevator","blender","treadmill","smoke-detector","syringe","kitchen-knife","fork","fountain-pen","thermos","pressure-cooker","jet-engine","football","winter-gloves","mustard","salsa","pickles","sauerkraut","jam","hazelnut-spread","shampoo","deodorant","air-freshener","dish-soap","foundation-makeup","padlock","fireworks","plastic-wrap","trading-cards","energy-drink","tampon","soap","toothpaste","plastic-bag","nitrile-glove","vacuum-cleaner","paperclip","donut","corn-flakes","cotton-candy","crayon","candle","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","cough-syrup","light-switch","facial-tissue","condensed-milk","baby-formula","coconut-milk","canned-soup","mayonnaise","aa-battery","candy-cane","toffee"],"steps":[{"name":"Make hydrogen from gas","process":"react","text":"Natural gas is cleaned and reacted with steam over a nickel catalyst, which strips out hydrogen and leaves carbon dioxide as a byproduct. Plants in some regions use coal for this step instead.","inputs":["natural-gas","water"]},{"name":"Take nitrogen from air","process":"react","text":"Air is added in a second reactor where its oxygen is burned away, which leaves nitrogen mixed into the hydrogen stream. Air is about 78% nitrogen, but that nitrogen is so stable that it takes a catalyst and high pressure to make it react.","inputs":["air"]},{"name":"Scrub out the carbon dioxide","process":"wash","text":"Carbon dioxide and traces of other gases are washed out of the mixture, because they would poison the catalyst. The carbon dioxide is often sold to urea and beverage plants.","inputs":[]},{"name":"Compress the gas mix","process":"press","text":"Multistage compressors squeeze the clean hydrogen and nitrogen to a very high pressure. The compressors are among the biggest machines in the plant.","inputs":[]},{"name":"Pass it over the iron catalyst","process":"react","text":"The hot, pressurized gas flows through beds of iron catalyst. Only about 15% of it turns into ammonia on each pass.","inputs":[]},{"name":"Chill out the liquid","process":"chill","text":"Refrigeration condenses the ammonia into a liquid that is drained off and stored. The gas that did not react goes back to the compressor, and after many laps nearly all of it ends up as ammonia.","inputs":[]}],"facts":["Making ammonia uses roughly 1 to 2% of the world's energy and causes about 3% of global carbon dioxide emissions.","The first industrial ammonia plant opened in 1913 at Oppau in Germany, after Fritz Haber's lab success and Carl Bosch's scale-up at BASF.","The iron catalyst still used today was found by BASF researcher Alwin Mittasch, who tested it as a cheaper alternative to rarer metals."],"where":[],"whereNote":null,"sources":[{"title":"Haber process","url":"https://en.wikipedia.org/wiki/Haber_process"},{"title":"Ammonia","url":"https://en.wikipedia.org/wiki/Ammonia"},{"title":"Steam reforming","url":"https://en.wikipedia.org/wiki/Steam_reforming"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"apples","name":"Apples","kind":"raw","category":"farm","title":"How apples are grown","url":"https://assemblyline.org/make/apples","stations":4,"upstream":0,"downstream":1,"depth":0,"dek":"Plant an apple seed and you get a tree unlike its parent, so every orchard apple is a graft.","answer":"Apples do not breed true from seed, so growers clone the varieties they want by grafting cuttings onto rootstocks. The rootstock sets how big the tree grows and how soon it fruits. Crews pick by hand from ladders, and sealed cold rooms with little oxygen hold the crop fresh for months.","aka":["apple","apple orchard","eating apples"],"inputs":[],"uses":["hard-cider"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["hard-cider"],"steps":[{"name":"Graft a cutting onto roots","process":"grow","text":"A seedling apple is a gamble, so nurseries join a cutting of the wanted variety to a separate rootstock. Dwarfing rootstocks keep the tree under about 3 meters and make it bear fruit years earlier.","inputs":[],"spec":"dwarf trees under 3.0 m"},{"name":"Mix varieties for pollination","process":"grow","text":"Most apple varieties cannot fertilize themselves. Orchards plant compatible varieties that bloom at the same time, and bees carry the pollen between them.","inputs":[]},{"name":"Pick from three-point ladders","process":"harvest","text":"Pickers climb ladders built to fit between the branches and lift fruit by hand as each variety ripens. A full-size tree can give 40 to 200 kilograms in a year, while a dwarf tree gives far less.","inputs":[],"spec":"40 to 200 kg per full-size tree"},{"name":"Hold them in cold, low-oxygen rooms","process":"chill","text":"Sealed storage rooms keep humidity high, oxygen low and carbon dioxide controlled, which slows ripening. This lets a fall harvest be sold all year.","inputs":[]}],"facts":["More than 7,500 apple cultivars exist, and each one is kept alive by grafting because its seeds will not repeat it.","Controlled-atmosphere storage for apples was first researched at Cambridge University in the 1920s.","The wild ancestor of the apple still grows in the mountains of Central Asia."],"where":[],"whereNote":null,"sources":[{"title":"Apple","url":"https://en.wikipedia.org/wiki/Apple"},{"title":"Apple juice","url":"https://en.wikipedia.org/wiki/Apple_juice"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"argon","name":"Argon","kind":"material","category":"chemicals","title":"How argon is separated from air","url":"https://assemblyline.org/make/argon","stations":5,"upstream":1,"downstream":188,"depth":1,"dek":"Argon is the third most abundant gas in the air we breathe, more than twice as plentiful as water vapor.","answer":"Argon makes up 0.934 percent of the atmosphere, and plants get it by liquefying air and distilling it. Air is filtered, compressed, cooled until liquid and then fed to tall cold columns where each gas boils off at its own temperature. Argon is drawn off along with oxygen and nitrogen.","aka":["Ar","argon gas"],"inputs":["air"],"uses":["silicon-wafer","steel","stainless-steel","titanium","light-bulb","double-glazed-window","neon-sign"],"grounds":["air"],"upstreamSlugs":["air"],"downstreamSlugs":["silicon-wafer","steel","stainless-steel","titanium","light-bulb","double-glazed-window","neon-sign","microchip","memory-chip","camera-sensor","solar-cell","inkjet-printer","toothbrush","lithium-ion-cell","ev-battery","aa-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","electric-toothbrush","syringe","washing-machine","electric-kettle","kitchen-knife","fork","razor-blade","fountain-pen","thermos","water-bottle","pressure-cooker","blender","asthma-inhaler","smartwatch","pacemaker","hip-implant","jet-engine","prosthetic-leg","aluminum-window-frame","hearing-aid","thermometer","credit-card","smartphone","laptop","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","rocket","wireless-earbuds","phone-charger","digital-camera","game-console","wifi-router","e-reader","graphics-card","remote-control","solar-panel","refrigerator","microwave-oven","air-conditioner","treadmill","safety-pin","car","ceiling-fan","water-heater","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","concrete","skyscraper","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sailboat","action-figure","power-outlet","champagne","pencil","mirror","golf-ball","wallpaper","wooden-chair","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","snow-globe","toffee"],"steps":[{"name":"Filter and compress the air","process":"separate","text":"Air is pre-filtered for dust and compressed. Water condenses out between the compression stages.","inputs":["air"]},{"name":"Chill it to a liquid","process":"chill","text":"Heat exchangers inside an insulated cold box cool the compressed air until it liquefies. Letting part of the compressed stream expand supplies the cold.","inputs":[]},{"name":"Boil it apart in columns","process":"refine","text":"Liquid air is distilled so each component boils off at its own temperature. Nitrogen and oxygen leave at opposite ends of the column.","inputs":[]},{"name":"Draw off a side stream","process":"separate","inputs":[],"text":"Argon boils between nitrogen and oxygen, so it is drawn from the middle of the column. It is a side product of a plant that mainly makes the other two gases."},{"name":"Polish and bottle the liquid","process":"refine","inputs":[],"text":"The crude side stream is purified again for demanding users such as semiconductor plants, then stored as liquid and filled into cylinders or tankers."}],"facts":["Argon's name comes from the Greek for lazy or inactive.","Lord Rayleigh and Sir William Ramsay first isolated it from air in 1894.","Argon shields welds and graphite furnaces from oxygen."],"where":[],"whereNote":null,"sources":[{"title":"Argon","url":"https://en.wikipedia.org/wiki/Argon"},{"title":"Air separation","url":"https://en.wikipedia.org/wiki/Air_separation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"asphalt","name":"Asphalt","kind":"material","category":"chemicals","title":"How asphalt is made","url":"https://assemblyline.org/make/asphalt","stations":5,"upstream":2,"downstream":2,"depth":1,"dek":"Asphalt is the thick black leftover from the bottom of the distillation tower, mixed hot with gravel.","answer":"Asphalt starts as bitumen, the heaviest residue left at the bottom of the refinery's distillation towers. Heavier crude oils are boiled further under vacuum so lighter oils leave and a thick binder remains. At an asphalt plant, the binder is heated and coated onto hot gravel and sand, then laid while still hot.","aka":["bitumen","blacktop"],"inputs":["crude-oil","gravel"],"uses":["road","roof-shingle"],"grounds":["crude-oil","gravel"],"upstreamSlugs":["crude-oil","gravel"],"downstreamSlugs":["road","roof-shingle"],"steps":[{"name":"Distill off the light oils","process":"refine","text":"Crude oil from heavier grades is boiled in a distillation tower, and everything lighter than the bottom residue rises away. What drains from the base is thick and black.","inputs":["crude-oil"]},{"name":"Boil it again under vacuum","process":"refine","text":"The residue is boiled again at low pressure, so more oil leaves without the heat cracking the molecules. The remaining refined bitumen is similar in thickness to cold molasses.","inputs":[]},{"name":"Adjust the binder","process":"mix","text":"Refiners blend or treat the bitumen to hit a target hardness. Some grades are modified with polymers or with air to make them stiffer or more elastic.","inputs":[]},{"name":"Dry and heat the aggregate","process":"dry","text":"At the asphalt plant, gravel and sand are dried in a rotating drum. They must be hot and dry for the binder to stick.","inputs":["gravel"]},{"name":"Coat the stone in binder","process":"mix","text":"Hot bitumen is mixed with the stone in a pugmill until every piece is coated. The mix is kept hot in a silo and loaded into trucks.","inputs":[]}],"facts":["About 70% of annual bitumen production goes to road construction.","The largest natural deposit of bitumen in the world is the Pitch Lake in southwest Trinidad.","In American English the manufactured binder is usually called asphalt, while much of the rest of the world calls it bitumen."],"where":[],"whereNote":null,"sources":[{"title":"Bitumen","url":"https://en.wikipedia.org/wiki/Bitumen"},{"title":"Oil refinery","url":"https://en.wikipedia.org/wiki/Oil_refinery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"road","name":"Asphalt road","kind":"product","category":"minerals","title":"How asphalt roads are made","url":"https://assemblyline.org/make/road","stations":6,"upstream":3,"downstream":0,"depth":2,"dek":"Doubling the weight on a truck axle does 16 times as much damage to the road beneath it.","answer":"An asphalt road is crushed stone coated in hot bitumen, spread over a compacted base and rolled flat. The stone is dried and heated to around 150 °C, mixed with hot bitumen at a plant, trucked out and laid in layers. Compaction has to happen while the mix is still hot, before the binder stiffens.","aka":["asphalt pavement","blacktop","tarmac","hot-mix asphalt"],"inputs":["gravel","asphalt"],"uses":[],"grounds":["gravel","crude-oil"],"upstreamSlugs":["gravel","asphalt","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Compact a base course","process":"press","text":"On site, crews prepare a compacted base of stone under the new surface. Good drainage keeps water out of the base and the soil beneath.","inputs":["gravel"]},{"name":"Quarry and crush stone","process":"crush","text":"Gravel and crushed rock make up the bulk of the mix. They are the mineral aggregate that gives the pavement its strength.","inputs":["gravel"]},{"name":"Heat and dry the stone","process":"dry","text":"In the hot-mix process, the aggregate is dried to remove moisture and heated to about 150 °C. Polymer-modified mixes are mixed at about 170 °C.","inputs":[],"spec":"about 150 °C"},{"name":"Coat it in bitumen","process":"mix","text":"Hot bitumen, at about 93 °C, is blended with the stone until every piece is coated. Bitumen is the sticky, viscous petroleum residue that binds the aggregate together.","inputs":["asphalt"]},{"name":"Lay the hot mix","process":"cast","text":"Trucks carry the mix to the site and it is spread in layers. Laying has to be done while the asphalt is hot enough to work.","inputs":[]},{"name":"Roll it flat","process":"roll","text":"Rollers compact the layers while they are still hot. Poor compaction, especially at the longitudinal joint, can cut a pavement's life by 30 to 40%.","inputs":[]}],"facts":["Edgar Purnell Hooley patented tarmac in 1901 after noticing that spilled tar kept the dust down.","The damage a vehicle causes is roughly proportional to the axle load raised to the fourth power."],"where":[],"whereNote":null,"sources":[{"title":"Asphalt concrete","url":"https://en.wikipedia.org/wiki/Asphalt_concrete"},{"title":"Road surface","url":"https://en.wikipedia.org/wiki/Road_surface"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"roof-shingle","name":"Asphalt shingle","kind":"product","category":"minerals","title":"How asphalt shingles are made","url":"https://assemblyline.org/make/roof-shingle","stations":5,"upstream":41,"downstream":0,"depth":8,"dek":"The crushed stone on a shingle is there to block sunlight, since UV light would eat the asphalt below.","answer":"An asphalt shingle is built on a base mat, today usually of glass fiber. The mat is coated with asphalt that contains mineral filler to make it waterproof, and crushed stone granules are pressed into the top surface. A sealant strip on the underside bonds each shingle to the one below it.","aka":["asphalt shingle","roofing shingle"],"inputs":["fiberglass","asphalt","limestone","gravel","adhesive"],"uses":[],"grounds":["limestone","gravel","silica-sand","crude-oil","water","rock-salt","trona","natural-gas","air","corn","sulfur","sugarcane","sugar-beet","coal"],"upstreamSlugs":["fiberglass","asphalt","limestone","gravel","adhesive","silica-sand","soda-ash","crude-oil","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","rock-salt","ammonia","carbon-dioxide","lime","trona","ethylene","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","hydrogen","natural-gas","air","corn","yeast","naphtha","sulfur","benzene","molasses","toluene","sugarcane","sugar-beet","coal"],"downstreamSlugs":[],"steps":[{"name":"Form the glass mat","process":"laminate","text":"Wet, random-laid glass fibers are bonded with resin into a thin mat. This base gives the shingle its strength and holds the asphalt.","inputs":["fiberglass"]},{"name":"Coat it with filled asphalt","process":"coat","text":"The mat is run through hot asphalt that has mineral filler stirred into it. The coating makes the shingle waterproof.","inputs":["asphalt","limestone"]},{"name":"Press in the granules","process":"press","text":"Crushed stone or ceramic granules are pressed into the hot surface. They block ultraviolet light that would degrade the asphalt, protect it from damage and provide the color.","inputs":["gravel"]},{"name":"Stripe on the sealant","process":"coat","text":"A strip of adhesive is put on the back of the shingle. In the sun, it softens and sticks the shingle down to the layer beneath.","inputs":["adhesive"]},{"name":"Cool and cut","process":"cut","text":"The continuous sheet is cooled, cut into shingle shapes and stacked into bundles.","inputs":[]}],"facts":["Asphalt shingles are an American invention by Henry Reynolds of Grand Rapids, Michigan, first used in 1903.","Fiberglass shingles overtook organic felt shingles in use by 1982."],"where":[],"whereNote":null,"sources":[{"title":"Asphalt shingle","url":"https://en.wikipedia.org/wiki/Asphalt_shingle"},{"title":"Roof shingle","url":"https://en.wikipedia.org/wiki/Roof_shingle"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"aspirin","name":"Aspirin","kind":"product","category":"body-health","title":"How aspirin is made","url":"https://assemblyline.org/make/aspirin","stations":7,"upstream":38,"downstream":0,"depth":7,"dek":"Willow bark started aspirin, but the factory version starts from phenol and carbon dioxide.","answer":"Aspirin starts as salicylic acid, a molecule once extracted from willow bark and now made from petroleum-derived chemicals. In a closed reactor it is combined with an acetyl-donating chemical, then crystallized, washed and dried. The pure white powder is blended with a starch binder, pressed into tablets and coated or packed in blister strips.","aka":["acetylsalicylic acid","ASA"],"inputs":["phenol","caustic-soda","carbon-dioxide","sulfuric-acid","acetic-anhydride","water","corn-starch","aluminum-foil","plastic-bottle"],"uses":[],"grounds":["water","air","rock-salt","natural-gas","corn","limestone","sulfur","crude-oil","coal","sugarcane","sugar-beet","bauxite"],"upstreamSlugs":["phenol","caustic-soda","carbon-dioxide","sulfuric-acid","acetic-anhydride","water","corn-starch","aluminum-foil","plastic-bottle","benzene","propylene","air","rock-salt","natural-gas","corn","yeast","limestone","sulfur","methanol","carbon-monoxide","aluminum","pet-plastic","naphtha","hydrogen","toluene","crude-oil","molasses","coal","petroleum-coke","alumina","p-xylene","ethylene","ethylene-glycol","sugarcane","sugar-beet","bauxite","lime","oxygen"],"downstreamSlugs":[],"steps":[{"name":"Build the salicylic acid","process":"react","text":"In the Kolbe-Schmitt route, phenol from petrochemicals reacts with a strong base and carbon dioxide gas. Acid then releases salicylic acid from the salt.","inputs":["phenol","caustic-soda","carbon-dioxide","sulfuric-acid"]},{"name":"Acetylate in glass-lined vessels","process":"react","text":"Salicylic acid meets acetic anhydride in glass-lined vessels, which attaches an acetyl group. Acetic acid comes off as a byproduct.","inputs":["acetic-anhydride"]},{"name":"Crystallize the powder","process":"separate","text":"The liquid is pumped to a crystallizer and cooled. Filtering removes the acetic acid and solvent, which are recycled.","inputs":[]},{"name":"Wash and dry","process":"wash","text":"The crystals are washed, filtered and dried into the pure active powder.","inputs":["water"]},{"name":"Blend with excipients","process":"mix","text":"A tablet plant weighs each ingredient, sizes it, and tumbles it with binder in a blender until the mix is uniform. Direct compression or a granulating step gets it flowing freely.","inputs":["corn-starch"]},{"name":"Press the tablets","process":"press","text":"A rotary press overfills its dies with powder, squeezes it between punches, and scrapes each ejected tablet away. Testers check hardness, thickness and how fast it falls apart.","inputs":[]},{"name":"Coat and pack","process":"package","text":"Some tablets go through a coating pan, sometimes with an enteric coat. Blister or strip machines then seal them in foil, or they are counted into bottles.","inputs":["aluminum-foil","plastic-bottle"]}],"facts":["Salicin from willow bark has been used for its health effects for at least 2,400 years.","Felix Hoffmann, or perhaps Arthur Eichengrün, of Bayer was the first to make acetylsalicylic acid in a pure, stable form in 1897.","An estimated 40,000 tonnes of aspirin are consumed worldwide each year."],"where":[],"whereNote":null,"sources":[{"title":"Procurement Resource: Aspirin production from salicylic acid via acetylation","url":"https://www.procurementresource.com/cost-analysis/aspirin-production-from-salicylic-acid-via-acetylation-with-acetic-anhydride"},{"title":"Pharmapproach: Tablet manufacturing steps","url":"https://www.pharmapproach.com/?p=2558"},{"title":"Tableting","url":"https://en.wikipedia.org/wiki/Tableting"},{"title":"The Science Snail: Organic synthesis of aspirin from benzene","url":"https://sciencesnail.com/science/organic-synthesis-of-aspirin-from-benzene"},{"title":"Aspirin","url":"https://en.wikipedia.org/wiki/Aspirin"},{"title":"Salicylic acid","url":"https://en.wikipedia.org/wiki/Salicylic_acid"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"asthma-inhaler","name":"Asthma inhaler","kind":"product","category":"body-health","title":"How asthma inhalers are made","url":"https://assemblyline.org/make/asthma-inhaler","stations":6,"upstream":42,"downstream":0,"depth":7,"dek":"The valve that meters each puff of an inhaler was first designed for dispensing perfume.","answer":"A metered-dose inhaler has three parts: a canister of aluminum or stainless steel formed by deep drawing, a metering valve, and a plastic actuator. The canister is filled with the drug dissolved or suspended in a liquefied gas propellant, sealed with the valve, and fitted with the mouthpiece. Each press releases one dose.","aka":["puffer","metered-dose inhaler","MDI"],"inputs":["aluminum","stainless-steel","refrigerant","plastic"],"uses":[],"grounds":["crude-oil","coal","fluorspar","natural-gas","bauxite","water","chromite","limestone","air","nickel-ore","sulfur","rock-salt","corn","trona","sugarcane","sugar-beet"],"upstreamSlugs":["aluminum","stainless-steel","refrigerant","plastic","crude-oil","coal","petroleum-coke","alumina","steel-scrap","chromium","nickel","oxygen","argon","fluorspar","sulfuric-acid","chlorine","ammonia","carbon-dioxide","propane","naphtha","natural-gas","ethylene","propylene","bauxite","caustic-soda","lime","water","chromite","coke","soda-ash","limestone","air","nickel-ore","sulfur","rock-salt","corn","yeast","hydrogen","trona","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Draw the canister","process":"stamp","text":"The canister is produced in aluminum or stainless steel by deep drawing, in which a flat blank is pressed into a cup shape without a weld.","inputs":["aluminum","stainless-steel"]},{"name":"Coat the surfaces","process":"coat","text":"A coating on the canister and valve stops the drug from sticking to the walls. One method is gas plasma processing in a vacuum, which extends shelf life.","inputs":[]},{"name":"Prepare the formulation","process":"mix","text":"The drug is dissolved or suspended in a liquefied gas propellant, now usually a hydrofluoroalkane. The propellant makes up over 99 percent of the delivered dose, so its properties matter more than any other single factor.","inputs":["refrigerant"]},{"name":"Fill and crimp the valve","process":"fill","text":"The formulation goes into the canister and a metering valve is sealed on. The valve lets out a set quantity each time it is pressed.","inputs":[]},{"name":"Fit the actuator","process":"assemble","text":"A mouthpiece actuator is fitted, along with a dose counter in many designs. The actuator directs the aerosol toward the lungs.","inputs":["plastic"]},{"name":"Test the doses","process":"inspect","text":"Inhalers are tested to confirm each puff delivers the right amount of medicine and a mist of tiny particles.","inputs":[]}],"facts":["Metered-dose inhalers were first developed in 1955 by Riker Laboratories.","The Meshburg metering valve at the heart of the first inhaler was originally designed for dispensing perfume.","Replacing CFC propellants with hydrofluoroalkanes in the 1990s forced a redesign, and for one steroid inhaler the smaller particles raised potency by a factor of 2.6."],"where":[],"whereNote":null,"sources":[{"title":"Metered-dose inhaler","url":"https://en.wikipedia.org/wiki/Metered-dose_inhaler"},{"title":"Aerosol spray","url":"https://en.wikipedia.org/wiki/Aerosol_spray"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"baby-formula","name":"Baby formula","kind":"product","category":"food","title":"How baby formula is made","url":"https://assemblyline.org/make/baby-formula","stations":6,"upstream":61,"downstream":0,"depth":9,"dek":"Formula starts as cow's milk, then the protein balance, fats and vitamins are rebuilt to look more like human milk.","answer":"Skim milk, whey, vegetable oils, lactose, vitamins and minerals are blended in big stainless steel tanks, pasteurized, homogenized and tested against a nutrient specification. Liquid formula is heat-sterilized in cans. Powder formula goes through a spray dryer first. Every step is tightly regulated, since the product is a baby's only food.","aka":["infant formula","formula milk","baby milk"],"inputs":["raw-milk","vegetable-oil","tin-can"],"uses":[],"grounds":["raw-milk","soybeans","rapeseed","water","clay","crude-oil","natural-gas","tin-ore","corn","sugarcane","air","titanium-ore","iron-ore","sulfur","limestone","dolomite","manganese-ore","coal","rock-salt","quartz","timber","sugar-beet"],"upstreamSlugs":["raw-milk","vegetable-oil","tin-can","soybeans","rapeseed","hexane","water","clay","tinplate","lacquer","ink","crude-oil","hydrogen","steel","tin","ethanol","acrylic","phenolic-resin","carbon-black","titanium-dioxide","pigment","natural-gas","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","tin-ore","coke","corn","sugarcane","yeast","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","formaldehyde","air","titanium-ore","chlorine","iron-ore","sulfur","limestone","dolomite","silicon","propane","manganese-ore","coal","molasses","naphtha","benzene","rock-salt","quartz","charcoal","timber","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Blend the base","process":"mix","text":"Skim milk is brought to a set temperature in stainless steel tanks. Fats, oils and emulsifiers go in next, and then minerals, vitamins and gums are added at different points, depending on how sensitive each is to heat.","inputs":["raw-milk","vegetable-oil"],"spec":"skim milk at 60 °C"},{"name":"Hold it hot briefly","process":"pasteurize","text":"The blend is piped to a pasteurizer that heats it quickly and cools it again, to cut down bacteria, yeasts and molds before filling.","inputs":[],"spec":"85 to 94 °C for about 30 seconds"},{"name":"Shear the fat droplets","process":"mix","text":"Homogenizing equipment applies shear and breaks the oils into very small droplets. This keeps the emulsion uniform and stable through the can's shelf life.","inputs":[]},{"name":"Check against the spec","process":"inspect","text":"Lab tests confirm pH, fat concentration and vitamin and mineral content. If any value is off, the batch is reworked until it is right.","inputs":[]},{"name":"Sterilize or dry","process":"dry","text":"Liquid formula is sterilized by UHT before filling, or in a retort after the can is sealed. Powdered formula goes through a spray dryer instead, as in other milk powders.","inputs":[],"spec":"UHT: 142 °C for 2 to 3 seconds"},{"name":"Fill and seal","process":"fill","text":"Liquid formula goes into metal cans with lids crimped on. Powder is packed into its own sealed containers.","inputs":["tin-can"]}],"facts":["The world's first commercial infant formula went on sale in 1867.","Plain cow's milk is wrong for infants partly because it has too much casein and too little whey, so formula makers adjust the ratio.","In the 1930s evaporated milk formulas were so common that by 1950 over half of American babies were raised on them."],"where":[],"whereNote":null,"sources":[{"title":"Infant formula","url":"https://en.wikipedia.org/wiki/Infant_formula"},{"title":"Powdered milk","url":"https://en.wikipedia.org/wiki/Powdered_milk"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"backpack","name":"Backpack","kind":"product","category":"textiles","title":"How backpacks are made","url":"https://assemblyline.org/make/backpack","stations":6,"upstream":51,"downstream":0,"depth":9,"dek":"A backpack can have hundreds of cut pieces, and one German maker assembles its packs across up to 22 sewing stations.","answer":"Backpacks are cut from tough woven nylon or polyester, usually with dies, and the panels are sewn together with heavy thread. Padded shoulder straps and a foam back panel are made separately. Zippers, buckles and webbing are added, stress points get bar tacks, and each bag is checked for loose stitching before packing.","aka":["rucksack","knapsack","schoolbag","daypack"],"inputs":["nylon","polyester","polyurethane","polyethylene","thread","zipper","plastic"],"uses":[],"grounds":["water","natural-gas","air","crude-oil","rock-salt","coal","sulfur","copper-ore","zinc-ore","lead-ore","tin-ore","bauxite","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["nylon","polyester","polyurethane","polyethylene","thread","zipper","plastic","benzene","nitric-acid","ammonia","pet-plastic","propylene","chlorine","water","ethylene","brass","aluminum","naphtha","natural-gas","hydrogen","toluene","air","p-xylene","ethylene-glycol","crude-oil","rock-salt","sulfuric-acid","copper","zinc","lead","tin","coal","petroleum-coke","alumina","oxygen","carbon-dioxide","sulfur","copper-ore","zinc-ore","lead-ore","coke","tin-ore","bauxite","caustic-soda","lime","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Weave heavy nylon cloth","process":"weave","text":"Thick nylon or polyester yarn is woven into a coarse, abrasion-resistant cloth. A urethane coat on the back of the fabric makes it shed water.","inputs":["nylon","polyester","polyurethane"]},{"name":"Cut stacks of panels","process":"cut","text":"Spread layers of fabric are cut with CNC knives, lasers or, most commonly, steel dies. The number of cut components in a backpack can run to hundreds.","inputs":[]},{"name":"Make the straps and back pad","process":"mold","text":"Foam is cut or molded to shape and covered in mesh and fabric. Shoulder straps and the back panel are sewn separately, since they carry the load and need the strongest stitching.","inputs":["polyethylene"]},{"name":"Sew the pockets and zips","process":"sew","text":"Zippers and pocket linings are stitched into the flat panels before the bag is closed up. Working on flat pieces is faster and neater than sewing into a finished sack.","inputs":["thread","zipper"]},{"name":"Close the body","process":"sew","text":"The side panels are sewn to the front and back with the seams inside, and the straps are stitched on. Bar tack machines reinforce every point that carries load, and the bag is turned right side out.","inputs":[]},{"name":"Add buckles and inspect","process":"inspect","text":"Plastic buckles, sliders and webbing are threaded through. Each bag is checked for loose threads and stitching, then folded flat and packed.","inputs":["plastic"]}],"facts":["The word backpack is first recorded in 1896, and until the middle of the 20th century the usual name was knapsack.","Hikers use backpacks with external or internal frames to shift a heavy load from the shoulders onto the hips."],"where":[],"whereNote":null,"sources":[{"title":"Backpack","url":"https://en.wikipedia.org/wiki/Backpack"},{"title":"Backpack manufacturing process (Online Clothing Study)","url":"https://onlineclothingstudy.com/2022/12/backpack-manufacturing-process.html"},{"title":"Production steps (Tatonka)","url":"https://openfactory.tatonka.com/produktion/production-steps/?lang=en"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bacon","name":"Bacon","kind":"product","category":"food","title":"How bacon is made","url":"https://assemblyline.org/make/bacon","stations":7,"upstream":10,"downstream":0,"depth":3,"dek":"Bacon is pork belly cured in salty brine with nitrite, then smoked for up to eighteen hours.","answer":"Bacon is salt-cured pork, usually from the belly. Factories inject the belly with a brine that carries salt, sugar and nitrite, or soak it in brine. The cured slabs are then smoked over burning wood, cooked partway, chilled until firm so they can be sliced, and the slices are laid out on paper and packed.","aka":["streaky bacon","side bacon","smoked bacon","rashers"],"inputs":["pigs","table-salt","sugar","water"],"uses":[],"grounds":["pigs","water","rock-salt","seawater","sugarcane","sugar-beet","limestone"],"upstreamSlugs":["pigs","table-salt","sugar","water","rock-salt","seawater","sugarcane","sugar-beet","lime","limestone"],"downstreamSlugs":[],"steps":[{"name":"Trim the pork bellies","process":"cut","text":"Bellies are cut from the pig, trimmed to a uniform shape and sorted by thickness. Side bacon, or streaky bacon, comes from this cut and has long alternating layers of fat and muscle.","inputs":["pigs"]},{"name":"Mix the curing brine","process":"mix","text":"Water, salt, sugar and curing agents are dissolved. Brine contains nitrites or nitrates that speed curing and fix the color, and manufacturers may add sodium polyphosphates to make the finished product easier to slice and reduce spattering in the pan.","inputs":["table-salt","sugar","water"]},{"name":"Inject the belly","process":"react","text":"A row of needles pumps the brine deep into each belly, which is much faster than soaking or dry-rubbing. The meat then rests in a cooler so the cure spreads evenly.","inputs":[]},{"name":"Smoke over wood","process":"cook","text":"Cured bellies hang in a smokehouse. Different woods give different flavors, and the process can take up to eighteen hours depending on how intense the smoke flavor should be.","inputs":[]},{"name":"Chill until firm","process":"chill","text":"Bellies are cooled or lightly frozen, which makes the fat and lean firm enough to slice into even rashers without tearing.","inputs":[]},{"name":"Slice into rashers","process":"cut","text":"High-speed slicers cut the bellies into thin strips, and the slices drop in overlapping rows onto paper.","inputs":[]},{"name":"Weigh and pack cold","process":"package","text":"Slices are weighed into packs, sealed and kept refrigerated. Raw bacon is cooked before eating, and some smoked and boiled types are ready to eat.","inputs":[]}],"facts":["Bacon can be cured wet, by injecting or soaking in brine, or dry, by rubbing with salt.","Neither table salt nor the nitrites used for curing is naturally pink, so curing salt is dyed pink to tell it apart.","Canadian peameal bacon is wet-cured, unsmoked back bacon coated in fine-ground cornmeal."],"where":[],"whereNote":null,"sources":[{"title":"Bacon","url":"https://en.wikipedia.org/wiki/Bacon"},{"title":"Curing (food preservation)","url":"https://en.wikipedia.org/wiki/Curing_%28food_preservation%29"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bagel","name":"Bagel","kind":"product","category":"food","title":"How bagels are made","url":"https://assemblyline.org/make/bagel","stations":6,"upstream":34,"downstream":0,"depth":9,"dek":"A bagel is boiled before it is baked, and that dunk in hot water is what gives it a chewy, shiny crust.","answer":"Bagel dough is among the stiffest of any bread, kneaded from high-gluten flour with barely half its weight in water. Rings of dough rest in the cold for hours, get boiled for a minute or two, and then go into a hot oven. The boil sets the outside before the bake, which makes a chewy crust and dense crumb.","aka":["boiled bagel","New York bagel"],"inputs":["flour","water","yeast","table-salt","sugar","malted-barley","baking-soda"],"uses":[],"grounds":["water","wheat","rock-salt","seawater","sugarcane","sugar-beet","barley","trona","limestone","air","natural-gas","corn","crude-oil"],"upstreamSlugs":["flour","water","yeast","table-salt","sugar","malted-barley","baking-soda","wheat","vitamin-c","molasses","rock-salt","seawater","sugarcane","sugar-beet","lime","barley","trona","limestone","ammonia","soda-ash","carbon-dioxide","corn-starch","hydrogen","air","plastic-bottle","natural-gas","corn","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Knead a stiff dough","process":"knead","text":"Bread flour, water, salt and yeast are kneaded together with a little malt or other sweetener. The dough carries only about half its weight in water, so it is a tough job for a mixer.","inputs":["flour","water","yeast","table-salt","sugar","malted-barley"],"spec":"50 to 57% hydration"},{"name":"Form it into rings","process":"mold","text":"A machine cuts the dough into pieces and rolls each one into a ring with a hole in the middle. Work on the first commercially viable bagel machine began in 1958 and eventually replaced hand rolling.","inputs":[]},{"name":"Rest the rings in the cold","process":"chill","text":"Shaped rings sit for at least twelve hours at fridge temperature. A slow cold rise builds flavor and a better crust.","inputs":[],"spec":"at least 12 hours at 4 to 10 °C"},{"name":"Boil each ring","process":"cook","text":"The rings are dropped into hot water, sometimes with baking soda, malt syrup or honey added. The dunk gelatinizes the surface starch, which is the secret of the shiny, chewy skin.","inputs":["baking-soda"],"spec":"60 to 90 seconds"},{"name":"Bake it hot","process":"bake","text":"Boiled rings go into the oven, often with seeds or salt on top. Heat sets the crust and browns it.","inputs":[],"spec":"175 to 315 °C"},{"name":"Cool, slice or freeze","process":"package","text":"Bagels can be sliced and bagged fresh or frozen. Frozen ones keep for up to six months.","inputs":[]}],"facts":["A steam bagel skips the boil and is baked in an oven that injects steam, which gives a softer, fluffier result closer to a finger roll.","Harry Lender and his son Murray pioneered automated production of frozen bagels in the 1960s, and Murray invented pre-slicing the bagel.","Bagel dough is among the stiffest bread doughs, with hydration of only about 50 to 57 percent."],"where":[],"whereNote":null,"sources":[{"title":"Bagel","url":"https://en.wikipedia.org/wiki/Bagel"},{"title":"Bread","url":"https://en.wikipedia.org/wiki/Bread"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"baguette","name":"Baguette","kind":"product","category":"food","title":"How baguettes are made","url":"https://assemblyline.org/make/baguette","stations":7,"upstream":28,"downstream":0,"depth":9,"dek":"A traditional French baguette is limited by law to flour, water, yeast, salt and traces of extras, with no pre-made dough.","answer":"Flour, water, yeast and salt are mixed into a lean dough and allowed to ferment, often with a pre-ferment for flavor. The dough is divided, shaped into long thin loaves and proofed. A deck oven over 200 °C injects steam, which lets the crust expand before it sets. The result is a crisp crust and an airy crumb.","aka":["French stick","baguette de tradition"],"inputs":["flour","water","yeast","table-salt"],"uses":[],"grounds":["water","wheat","rock-salt","seawater","air","sugarcane","sugar-beet","corn","natural-gas","limestone","crude-oil"],"upstreamSlugs":["flour","water","yeast","table-salt","wheat","vitamin-c","molasses","rock-salt","seawater","corn-starch","hydrogen","air","sugar","plastic-bottle","sugarcane","sugar-beet","corn","natural-gas","lime","pet-plastic","limestone","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Mix a lean dough","process":"mix","text":"Wheat flour, water, baker's yeast and salt go into the mixer. The traditional baguette is defined by French law, which allows only small amounts of a few additions such as broad bean flour and malt flour.","inputs":["flour","water","yeast","table-salt"]},{"name":"Let the dough ferment","process":"ferment","text":"Yeast makes carbon dioxide, which inflates the dough. Artisan bakers often start with a pre-ferment called a poolish to deepen the flavor. Faster factory doughs ferment less and tend to taste of less.","inputs":[]},{"name":"Divide and shape the sticks","process":"mold","text":"The dough is cut into pieces and rolled into long thin loaves. Under the 1993 bread decree, traditional French bread cannot be made from pre-made dough.","inputs":[]},{"name":"Proof the loaves","process":"ferment","text":"Shaped loaves rest in a warm, humid room so they swell again before they meet the oven.","inputs":[],"spec":"60 to 90 minutes at 27 °C"},{"name":"Score the tops","process":"cut","inputs":[],"text":"A blade makes a few shallow cuts along the length of each loaf. The cuts let it open in the oven and are part of what marks a traditional baguette."},{"name":"Bake in a steam deck oven","process":"bake","text":"Loaves go onto a thick stone or firebrick deck in an oven heated over 200 °C. Steam injected at the start lets the crust stretch before it hardens and melts surface sugar into a slight glaze.","inputs":[],"spec":"205 to 220 °C, steam for the first 2 to 5 minutes"},{"name":"Cool on racks","process":"chill","text":"Loaves cool and crackle as the crust shrinks. A baguette is best eaten within hours, because the thin crust gives up its crunch quickly.","inputs":[]}],"facts":["Since 1994 the city of Paris has awarded a yearly prize for its best traditional baguette.","In 2022 the artisanal know-how and culture of baguette bread was inscribed on the UNESCO Intangible Cultural Heritage lists.","The first steam oven reached Paris in 1839, brought by August Zang, who is sometimes credited with originating the baguette."],"where":[],"whereNote":null,"sources":[{"title":"Baguette","url":"https://en.wikipedia.org/wiki/Baguette"},{"title":"Bread","url":"https://en.wikipedia.org/wiki/Bread"},{"title":"Baguette","url":"https://bakerpedia.com/processes/baguette/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"yeast","name":"Baker's yeast","kind":"material","category":"food","title":"How baker's yeast is made","url":"https://assemblyline.org/make/yeast","stations":6,"upstream":4,"downstream":348,"depth":2,"dek":"A factory grows yeast from a flask culture into tens of thousands of kilograms in a few days.","answer":"Baker's yeast, Saccharomyces cerevisiae, is grown in stages. A lab culture feeds a small fermenter, which seeds ever larger tanks. In the last tank, air and sugar are fed in carefully so the cells multiply instead of making alcohol. Centrifuges and filters then concentrate the cells into cream, cakes or dry granules.","aka":["bakers yeast","instant yeast","active dry yeast","compressed yeast"],"inputs":["water","molasses"],"uses":["insulin","ethanol","vinegar","bread","croissant","donut","pretzel","beer","wine","champagne","whiskey","vodka","gin","rum","tequila","sake","hard-cider","frozen-pizza","bagel","baguette","crackers","carbon-dioxide","bourbon","scotch","mead","port-wine","prosecco","light-beer","non-alcoholic-beer"],"grounds":["water","sugarcane","sugar-beet"],"upstreamSlugs":["water","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["insulin","ethanol","vinegar","bread","croissant","donut","pretzel","beer","wine","champagne","whiskey","vodka","gin","rum","tequila","sake","hard-cider","frozen-pizza","bagel","baguette","crackers","carbon-dioxide","bourbon","scotch","mead","port-wine","prosecco","light-beer","non-alcoholic-beer","deodorant","perfume","vaccine","gasoline","ink","vanilla-extract","lacquer","super-glue","insect-repellent","air-freshener","hairspray","mouthwash","mayonnaise","ketchup","mustard","hot-sauce","salsa","pickles","fish-sticks","aspirin","soda-ash","fertilizer","baking-soda","decaf-coffee","cola","sparkling-water","refrigerant","popping-candy","soda","root-beer","energy-drink","tonic-water","caffeine","melamine-resin","ethylene-glycol","shampoo","dish-soap","foundation-makeup","car","car-engine","motorcycle","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","ice-cream","white-chocolate","caramel","guitar","electric-guitar","trumpet","chopsticks","door","chess-set","saxophone","ukulele","felt-hat","baseball-bat","detergent","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","instant-noodles","stained-glass","vanadium","cake-mix","fire-extinguisher","refrigerator","air-conditioner","asthma-inhaler","pet-plastic","spandex","locomotive","vacuum-cleaner","electric-kettle","cotton-candy","pillow","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","electric-car","soap","toothpaste","nitrile-glove","washing-machine","paperclip","corn-flakes","popcorn","crayon","fireworks","candle","zip-bag","blender","dishwasher","cotton-swab","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","printed-circuit-board","wind-turbine","surfboard","fishing-rod","kite","roof-shingle","canoe","sailboat","lithium-ion-cell","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather","thermometer","lcd-screen","oled-screen","camera-sensor","solar-panel","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","neon-sign","smartwatch","e-reader","mirror","skyscraper","double-glazed-window","nail-polish","penicillin","kombucha","cognac","mezcal","smartphone","polyester","plastic-bottle","3d-printer-filament","drum-kit","bottled-water","leggings","swimsuit","pencil","scissors","airplane","container-ship","shipping-container","bicycle","wooden-chair","water-bottle","ceiling-fan","tennis-racket","golf-club","billiard-ball","dartboard","dice","action-figure","fashion-doll","toy-car","coil-spring","hammer","gas-cylinder","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","hearing-aid","pacemaker","led-bulb","ev-battery","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","airbag","rocket","elevator","treadmill","pinball-machine","phone-charger","digital-camera","graphics-card","electric-toothbrush","kitchen-knife","fork","fountain-pen","thermos","pressure-cooker","jet-engine","football","winter-gloves","handbag","wallet","hiking-boots","high-heels","leather-shoe","sauerkraut","jam","hazelnut-spread","tire","sofa","office-chair","garden-hose","volleyball","kitchen-sponge","wet-wipes","seat-belt","hoodie","raincoat","backpack","suitcase","shoelace","curtain","microphone","sneaker","mattress","zipper","button","thread","teddy-bear","sunscreen","bleach","vitamin-c","hair-dye","padlock","down-jacket","jeans","dress-shirt","suit","baseball-cap","bike-helmet","yo-yo","tampon","silk-tie","blanket","socks","sweater","towel","flour","tortilla","sandwich-cookie","chicken-nuggets","sourdough","modeling-clay","licorice"],"steps":[{"name":"Culture a pure strain","process":"grow","text":"A single selected strain grows in laboratory flasks for 2 to 4 days. Starting from one strain gives the same rise and flavor in every batch.","inputs":[],"spec":"2 to 4 days"},{"name":"Step up through small tanks","process":"ferment","text":"The culture moves into batch fermenters that run for 13 to 24 hours and then into larger intermediate tanks. Growth is fed gradually and aerated constantly. This stage makes more ethanol and other alcohols than the later ones.","inputs":["water"]},{"name":"Feed it molasses and air","process":"grow","text":"The sugar for growth usually comes from cane or beet molasses, the sticky by-product of sugar making. In the last big tanks, called the trade fermenters, air is pumped in hard for up to 15 hours. Oxygen and sugar are metered so alcohol production is suppressed by up to 95 percent and the cells put their energy into multiplying.","inputs":["molasses"],"spec":"up to 15 hours"},{"name":"Spin out the cream","process":"separate","text":"Centrifuges separate the yeast cells from the liquid they grew in. The resulting suspension is cream yeast, the form that industrial bakeries pump straight into dough mixers.","inputs":[]},{"name":"Filter and shape the blocks","process":"press","text":"A filter removes most of the remaining liquid, leaving a soft beige solid. It is extruded and cut into cakes or blocks of compressed yeast, which are highly perishable.","inputs":[]},{"name":"Dry and pack","process":"dry","text":"Some of the yeast is dried to active dry or instant granules and vacuum packed. Dry yeast travels long distances, while fresh yeast is mostly supplied from local factories.","inputs":[]}],"facts":["In 1996, after six years of work, S. cerevisiae became the first eukaryote to have its entire genome sequenced.","Yeast was grown in specialized vats in Great Britain from 1879, and centrifuges for concentrating it came around the turn of the century in the United States."],"where":[],"whereNote":null,"sources":[{"title":"Baker's yeast","url":"https://en.wikipedia.org/wiki/Baker%27s_yeast"},{"title":"Sugar","url":"https://en.wikipedia.org/wiki/Sugar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"baking-soda","name":"Baking soda","kind":"product","category":"food","title":"How baking soda is made","url":"https://assemblyline.org/make/baking-soda","stations":6,"upstream":15,"downstream":7,"depth":5,"dek":"Industrial baking soda is mined trona or soda ash bubbled with carbon dioxide until crystals fall out.","answer":"Baking soda, sodium bicarbonate, is made from sodium carbonate. Soda ash, either mined as trona or made by the Solvay process from salt brine and limestone, is dissolved in water and treated with carbon dioxide. Sodium bicarbonate is less soluble, so it precipitates as crystals that are filtered, dried and packed.","aka":["sodium bicarbonate","bicarbonate of soda","bread soda","saleratus"],"inputs":["trona","limestone","ammonia","rock-salt","soda-ash","water","carbon-dioxide"],"uses":["pretzel","sparkling-water","frozen-pizza","bagel","crackers","cake-mix","fire-extinguisher"],"grounds":["trona","limestone","rock-salt","water","natural-gas","air","corn","sugarcane","sugar-beet"],"upstreamSlugs":["trona","limestone","ammonia","rock-salt","soda-ash","water","carbon-dioxide","natural-gas","air","lime","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["pretzel","sparkling-water","frozen-pizza","bagel","crackers","cake-mix","fire-extinguisher"],"steps":[{"name":"Mine the trona","process":"mine","text":"In Wyoming's Green River basin, the biggest trona deposits are mined underground. Trona is a natural mineral that holds both sodium carbonate and sodium bicarbonate.","inputs":["trona"]},{"name":"Calcine to soda ash","process":"refine","text":"Crushed trona is heated so it gives up water and carbon dioxide and becomes soda ash, which is sodium carbonate. Where there is no trona, plants make soda ash with the Solvay process, using salt brine, limestone and ammonia that is recycled around the plant.","inputs":["limestone","ammonia","rock-salt"]},{"name":"Dissolve the soda ash","process":"mix","text":"Soda ash goes into water in large tanks until it forms a strong solution. Insoluble grit from the ore is filtered out first.","inputs":["soda-ash","water"]},{"name":"Carbonate the solution","process":"react","text":"Carbon dioxide gas is bubbled up through towers filled with the solution. Sodium carbonate takes up carbon dioxide and water and becomes sodium bicarbonate, which does not dissolve as well.","inputs":["carbon-dioxide"]},{"name":"Crystallize and filter","process":"grow","text":"Sodium bicarbonate comes out of solution as a solid. Filters or centrifuges pull the crystals from the liquid, which is sent back to dissolve more soda ash.","inputs":[]},{"name":"Dry, sieve and pack","process":"dry","text":"The wet crystals are dried gently, because heating above 80 °C would make them start breaking down. Screens sort them into grades from fine powder to coarse granules before bagging.","inputs":[]}],"facts":["In 1846 two American bakers, John Dwight and Austin Church, opened the first U.S. factory making baking soda from sodium carbonate and carbon dioxide.","An ad campaign that began in 1972 put a box of baking soda in more than half of American refrigerators within a year, though there is little evidence it removes odors."],"where":[],"whereNote":null,"sources":[{"title":"Sodium bicarbonate","url":"https://en.wikipedia.org/wiki/Sodium_bicarbonate"},{"title":"Solvay process","url":"https://en.wikipedia.org/wiki/Solvay_process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ball-bearing","name":"Ball bearing","kind":"product","category":"hardware","title":"How ball bearings are made","url":"https://assemblyline.org/make/ball-bearing","stations":9,"upstream":29,"downstream":23,"depth":6,"dek":"A bearing ball starts as a chopped piece of wire, squeezed in a machine named for making nail heads.","answer":"A ball bearing is two grooved steel rings with a ring of hard steel balls between them. Balls are cold-headed from wire, rolled free of flash, hardened, ground and lapped. Rings are cut from tube, hardened and ground. The inner ring goes inside the outer, balls drop in, and a cage spaces them.","aka":["bearing","deep-groove bearing"],"inputs":["steel-wire","steel","sheet-steel"],"uses":["electric-motor","washing-machine","locomotive","bicycle","motorcycle","elevator","skateboard","roller-skates","yo-yo"],"grounds":["iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","zinc-ore","coal","quartz","timber","crude-oil","sulfur"],"upstreamSlugs":["steel-wire","steel","sheet-steel","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","zinc-ore","coal","quartz","charcoal","timber","crude-oil","sulfur"],"downstreamSlugs":["electric-motor","washing-machine","locomotive","bicycle","motorcycle","elevator","skateboard","roller-skates","yo-yo","refrigerator","microwave-oven","vacuum-cleaner","drone","electric-car","blender","dishwasher","air-conditioner","treadmill","subway-train","game-console","inkjet-printer","graphics-card","skyscraper"],"steps":[{"name":"Head balls from wire","process":"forge","text":"A heading machine slams two hemispherical dies onto a slug of wire with no added heat. The result is a rough ball with a ring of excess metal, called flash, around its middle.","inputs":["steel-wire"]},{"name":"Roll off the flash","process":"grind","text":"Balls run through the grooves between two cast iron plates, one spinning and one still. The rough grooves tear off the flash and leave a slightly oversized ball.","inputs":[]},{"name":"Cut the rings","process":"machine","text":"Automatic machines cut steel tube to the basic shape of the inner and outer rings, leaving extra metal to allow for warping in the furnace. Outer rings are stamped with the bearing number.","inputs":["steel"]},{"name":"Harden everything","process":"heat-treat","text":"Rings and balls are heated, cooled in oil and tempered in a second oven, so they carry loads without denting.","inputs":[],"spec":"around 1550 degrees F"},{"name":"Grind the races","process":"grind","text":"The hardened rings are now too hard to cut, so wheels grind their width, radius and groove to size.","inputs":[]},{"name":"Grind and lap the balls","process":"grind","text":"Balls are ground to size, then roll between soft cast iron plates under low pressure with a polishing paste, until the surface is smooth.","inputs":[],"spec":"8-10 hours lapping"},{"name":"Stamp the cage","process":"stamp","text":"A press cuts the cage outline from thin sheet metal, and a die bends it to shape. Some cages are injection molded from plastic instead.","inputs":["sheet-steel"]},{"name":"Load and close","process":"assemble","text":"The inner ring goes inside the outer ring, balls drop into the gap and are spaced evenly, and the cage is snapped or riveted in to hold them apart.","inputs":[]},{"name":"Grease and seal","process":"package","text":"The bearing is coated with a rust preservative or packed with grease, then fitted with shields or seals and boxed.","inputs":[]}],"facts":["Philip Vaughan of Carmarthen, Wales, was awarded the first recorded patent on ball bearings in 1794.","In 1869, the winning bicycle in the first road race, Paris to Rouen, carried the first radial ball bearing, designed by Jules Suriray.","Finished bearing balls can be held to tolerances as small as a millionth of an inch."],"where":[],"whereNote":null,"sources":[{"title":"Ball bearing","url":"https://en.wikipedia.org/wiki/Ball_bearing"},{"title":"Rolling-element bearing","url":"https://en.wikipedia.org/wiki/Rolling-element_bearing"},{"title":"How Are Ball Bearings Made?","url":"https://www.mrosupply.com/blog/how-are-ball-bearings-made"},{"title":"How are the balls in ball bearings made?","url":"https://www.acorn-ind.co.uk/insight/how-are-the-balls-in-ball-bearings-made/"},{"title":"How are ball bearings made?","url":"https://www.howitworksdaily.com/how-are-ball-bearings-made/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"balloon","name":"Balloon","kind":"product","category":"plastics","title":"How balloons are made","url":"https://assemblyline.org/make/balloon","stations":8,"upstream":3,"downstream":0,"depth":1,"dek":"The white dust inside a latex balloon is leftover calcium nitrate, the coating that helped it peel off its form.","answer":"Latex balloons are dipped, not blown. A balloon-shaped form is washed with hot water, heated, dipped in calcium nitrate and dried, then dipped in latex. The neck is rolled up, the skin soaks in hot water, and an oven vulcanizes it at 140 to 160 °C. Finally it is coated with anti-tack slurry, stripped off and tumbled clean.","aka":["latex balloon","party balloon"],"inputs":["water","natural-latex","sulfur"],"uses":[],"grounds":["water","natural-latex","sulfur"],"upstreamSlugs":["water","natural-latex","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Wash and heat the form","process":"wash","text":"Every balloon starts on a reusable form blasted with high-pressure hot water. The form then rides through a preheated oven so the next coatings go on warm.","inputs":["water"]},{"name":"Dip in calcium nitrate","process":"coat","text":"The form dips into calcium nitrate, which coats it and helps with stripping later. An oven dries the coat before the rubber arrives. This is the white powder found inside finished balloons.","inputs":[]},{"name":"Dip into compounded latex","process":"coat","text":"The dry, coated form goes into a tank of latex, which already carries the sulfur, accelerator and activator it will need to cure, and comes out wearing a thin skin of rubber.","inputs":["natural-latex","sulfur"]},{"name":"Roll up the neck","process":"mold","text":"At the rolling station, the open edge of the skin curls up the form into the bead you stretch to tie a knot.","inputs":[]},{"name":"Leach in hot water","process":"wash","text":"Each form passes through a tank of hot water that pulls out leftover calcium nitrate and starts a light cure in the rubber.","inputs":["water"]},{"name":"Vulcanize in an oven","process":"heat-treat","text":"An oven finishes the cure at 140 to 160 °C. Sulfur links the rubber together here, and this is the step that gives the balloon its stretch and strength.","inputs":[],"spec":"140-160 °C"},{"name":"Coat with anti-tack slurry","process":"coat","text":"The form dips once more, this time into a slurry that coats the outside of the skin. It stops finished pieces from gluing themselves together and eases them off the form.","inputs":[]},{"name":"Strip and tumble","process":"separate","text":"The skin comes off the form and drops into a tumbler, where it is sprayed with a cleaning solution. After that it is ready to bag and sell.","inputs":[]}],"facts":["Michael Faraday invented the rubber balloon in 1824, during experiments with various gases.","Helium atoms escape through small pores in latex that are larger than the atoms, so a latex balloon floats for only a day or so."],"where":[],"whereNote":null,"sources":[{"title":"Bargain Balloons: how latex balloons are made","url":"https://support.bargainballoons.ca/support/solutions/articles/27000071964-how-latex-balloons-are-made"},{"title":"Balloon","url":"https://en.wikipedia.org/wiki/Balloon"},{"title":"Natural rubber","url":"https://en.wikipedia.org/wiki/Natural_rubber"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ballpoint-pen","name":"Ballpoint pen","kind":"product","category":"play","title":"How ballpoint pens are made","url":"https://assemblyline.org/make/ballpoint-pen","stations":7,"upstream":77,"downstream":0,"depth":8,"dek":"China made 38 billion ballpoint pens in 2017, yet for years imported the tiny tips from Germany, Switzerland and Japan.","answer":"A ballpoint pen is a tube of thick ink with a tiny ball seated in a socket at its tip. The ball, made of steel, brass or tungsten carbide, is set in a brass or steel holder. A plastic barrel is molded, the ink tube is filled, and the parts are snapped together and tested for writing.","aka":["biro","ball pen","ballpoint"],"inputs":["brass","tungsten-carbide","ink","polystyrene","abs-plastic","steel-wire"],"uses":[],"grounds":["water","air","copper-ore","zinc-ore","lead-ore","tin-ore","crude-oil","coal","tungsten-ore","cobalt-ore","soybeans","rapeseed","clay","titanium-ore","iron-ore","sulfur","corn","sugarcane","natural-gas","bauxite","rock-salt","limestone","dolomite","manganese-ore","sugar-beet","quartz","timber"],"upstreamSlugs":["brass","tungsten-carbide","ink","polystyrene","abs-plastic","steel-wire","copper","zinc","lead","tin","aluminum","tungsten","carbon-black","cobalt","vegetable-oil","phenolic-resin","titanium-dioxide","pigment","water","ethanol","naphtha","ethylene","benzene","styrene","propylene","ammonia","air","steel","copper-ore","oxygen","sulfuric-acid","zinc-ore","lead-ore","coke","tin-ore","crude-oil","coal","petroleum-coke","alumina","tungsten-ore","hydrogen","cobalt-ore","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","titanium-ore","chlorine","iron-ore","sulfur","corn","sugarcane","yeast","natural-gas","toluene","pig-iron","magnesium","steel-scrap","lime","manganese","argon","bauxite","caustic-soda","methanol","rock-salt","molasses","limestone","dolomite","silicon","propane","manganese-ore","sugar-beet","quartz","charcoal","timber"],"downstreamSlugs":[],"steps":[{"name":"Machine the tip socket","process":"machine","text":"A tiny holder is cut from brass or steel with a socket inside. The socket must hold the ball loosely enough to roll and tightly enough that it stays put.","inputs":["brass"]},{"name":"Drop the ball into the socket","process":"assemble","text":"A very small ball, often tungsten carbide, is placed in the socket, and the metal is crimped to hold it. Too tight a socket stops the roll, and too loose lets ink flood out.","inputs":["tungsten-carbide"]},{"name":"Mix the thick ink","process":"mix","text":"Ink for a ballpoint is a thick paste, not a thin liquid, so it dries fast on paper but does not run through the tip.","inputs":["ink"]},{"name":"Mold the barrel","process":"mold","text":"Barrels, caps and clicking parts are injection-molded in plastic.","inputs":["polystyrene","abs-plastic"]},{"name":"Fill the ink tube","process":"fill","text":"A narrow plastic tube is filled with ink and fitted to the tip.","inputs":[]},{"name":"Snap the pen together","process":"assemble","text":"Refill, barrel, spring and cap come together in a machine that makes many pens a minute.","inputs":["steel-wire"]},{"name":"Test the scribble","process":"inspect","text":"Machines draw lines to confirm each pen starts, writes smoothly and does not leak.","inputs":[]}],"facts":["For years China had to import the precision tips from Germany, Switzerland and Japan, at a cost of 120 million yuan a year.","The 1945 Reynolds Rocket was the first commercially successful ballpoint pen, and cost 12.50 dollars."],"where":[],"whereNote":null,"sources":[{"title":"Ballpoint pen","url":"https://en.wikipedia.org/wiki/Ballpoint_pen"},{"title":"Polystyrene","url":"https://en.wikipedia.org/wiki/Polystyrene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bamboo","name":"Bamboo","kind":"raw","category":"farm","title":"How bamboo is grown and harvested","url":"https://assemblyline.org/make/bamboo","stations":4,"upstream":0,"downstream":3,"depth":0,"dek":"A bamboo shoot pushes up at its full width and reaches full height in a single season.","answer":"Bamboo is a giant grass that spreads from underground rhizomes. Each new stalk, called a culm, emerges at its final diameter and grows to full height in three to four months, sometimes 91 centimeters in one day. Builders cut culms when they are strongest and their sap sugar is lowest.","aka":["bamboo culms","bamboo poles","giant grass"],"inputs":[],"uses":["chopsticks","kite","incense"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["chopsticks","kite","incense"],"steps":[{"name":"Spread by underground runners","process":"grow","text":"New plants spread from rhizomes below ground. Clumping types expand slowly, while running types send out long rhizomes and need controlling.","inputs":[]},{"name":"Shoot up in one season","process":"grow","text":"Unlike a tree, a culm never widens afterward. It rises with no branches until nearly full height, then the branches and leaves open out.","inputs":[],"spec":"3 to 4 months to full height"},{"name":"Cut at peak strength","process":"harvest","text":"Culms for building are cut when they have reached their greatest strength and the sugar in the sap is lowest. High sugar draws pests, so timing protects the wood.","inputs":[]},{"name":"Soak against beetles","process":"wash","text":"Bamboo has few natural toxins, and untreated poles may last only 2 to 6 years. Builders treat the culms with boron, commonly a mixture of borax and boric acid.","inputs":[]}],"facts":["Some bamboo species have been seen growing 91 centimeters in 24 hours, about 1 millimeter every 90 seconds.","Many bamboo species flower only at intervals as long as 65 or 120 years, and the plant often dies afterward.","The largest giant bamboo culm on record reached 46 meters in length."],"where":[],"whereNote":null,"sources":[{"title":"Bamboo","url":"https://en.wikipedia.org/wiki/Bamboo"},{"title":"Bamboo construction","url":"https://en.wikipedia.org/wiki/Bamboo_construction"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"banknote","name":"Banknote","kind":"product","category":"wood-paper","title":"How banknotes are made","url":"https://assemblyline.org/make/banknote","stations":6,"upstream":47,"downstream":0,"depth":8,"dek":"Paper banknotes are cotton, strengthened with gelatin, with the watermark built in as the sheet forms.","answer":"Most paper banknotes are printed on cotton paper, often blended with linen, made on a mold machine that builds the watermark and a thread into the sheet. Gelatin or polyvinyl alcohol strengthens the paper. Presses then print the layers of the design onto large sheets, which are cut into notes. Some countries print on plastic instead.","aka":["paper money","bill","currency note"],"inputs":["raw-cotton","flax","water","gelatin","polyvinyl-alcohol","ink"],"uses":[],"grounds":["raw-cotton","flax","water","pigs","cattle-hide","limestone","natural-gas","air","rock-salt","soybeans","rapeseed","clay","crude-oil","titanium-ore","iron-ore","sulfur","corn","sugarcane","coal","sugar-beet"],"upstreamSlugs":["raw-cotton","flax","water","gelatin","polyvinyl-alcohol","ink","pigs","cattle-hide","lime","ethylene","oxygen","methanol","caustic-soda","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","limestone","naphtha","natural-gas","air","rock-salt","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","hydrogen","benzene","propylene","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Beat cotton and linen fibers","process":"mix","text":"Cotton fiber, sometimes mixed with linen, abaca or other textile fibers, is blended with water into a slurry. Banknote paper is meant to resist wear far better than ordinary paper made from wood.","inputs":["raw-cotton","flax","water"]},{"name":"Form with a built-in thread","process":"cast","text":"On a mold-made paper machine, the watermark and a security thread are built into the sheet while it forms. The thread can look simple, but it is often built from several different layers.","inputs":[]},{"name":"Strengthen the sheet","process":"coat","text":"Banknote paper is infused with gelatin or polyvinyl alcohol rather than plain water, which gives it extra strength. It also lacks the brighteners that make ordinary paper glow under ultraviolet light.","inputs":["gelatin","polyvinyl-alcohol"]},{"name":"Print the layers","process":"print","text":"Large sheets pass through several presses, each laying down a layer of the design. Engraved-plate printing, called intaglio, is the traditional method.","inputs":["ink"]},{"name":"Inspect every sheet","process":"inspect","text":"Each sheet is checked automatically and by eye for printing faults before it is cut. Errors such as cutting and alignment mistakes can still occur and are caught here.","inputs":[]},{"name":"Cut and bundle the notes","process":"cut","text":"Guillotines cut the printed sheets into individual notes, which are counted into bundles for the central bank.","inputs":[]}],"facts":["The average life of a paper banknote is two years.","In 1988 Australia produced the first polymer banknote, made from biaxially oriented polypropylene, and by 1996 it had replaced all its paper notes.","United States banknotes are made of cotton fibers together with 25 percent linen."],"where":[],"whereNote":null,"sources":[{"title":"Banknote","url":"https://en.wikipedia.org/wiki/Banknote"},{"title":"Pulp (paper)","url":"https://en.wikipedia.org/wiki/Pulp_(paper)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"barbed-wire","name":"Barbed wire","kind":"product","category":"hardware","title":"How barbed wire is made","url":"https://assemblyline.org/make/barbed-wire","stations":7,"upstream":28,"downstream":0,"depth":6,"dek":"Before barbed wire, the first farmers around Fresno, California, spent nearly $4,000 on wooden fencing.","answer":"Steel billets are rolled into rods, then lubricated and pulled through dies into wire. The stiff wire is annealed so it bends, and galvanized against rust. In a barbing machine, two line wires feed in together and twist into a cable. A third wire enters from the side, wraps around the cable at set intervals and is cut at an angle, which leaves the sharp barbs.","aka":["barb wire","razor wire"],"inputs":["steel","zinc","steel-wire"],"uses":[],"grounds":["zinc-ore","air","iron-ore","limestone","dolomite","water","manganese-ore","natural-gas","sulfur","coal","quartz","timber","crude-oil"],"upstreamSlugs":["steel","zinc","steel-wire","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","iron-ore","coke","limestone","dolomite","silicon","propane","water","manganese-ore","natural-gas","sulfur","coal","quartz","charcoal","timber","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Roll the rod","process":"roll","text":"Ingots are heated and pushed through grooved rolls into billets, which are reheated and rolled down to wire rod.","inputs":["steel"]},{"name":"Draw the wire","process":"draw","text":"Lubricated rod is pulled through dies, each narrower than the last. The wire comes out far thinner and very stiff.","inputs":[]},{"name":"Anneal it soft","process":"heat-treat","text":"Heating in molten salt, molten lead or a nitrogen furnace makes the stiff wire pliable enough to twist.","inputs":[]},{"name":"Galvanize the wire","process":"coat","text":"The wire takes on a zinc coating to protect it from weather before going to the barbing machine.","inputs":["zinc"]},{"name":"Twist the line strands","process":"spin","text":"Two wires feed into the machine together and twist into a single cable. Tension is set with care, as too little loosens the barbs and too much weakens the wire.","inputs":[]},{"name":"Wrap and cut barbs","process":"assemble","text":"A separate wire comes in from the side. The machine twists it around the cable and cuts it at an angle, forming sharp points at each interval.","inputs":["steel-wire"]},{"name":"Reel it up","process":"package","text":"The finished strand winds onto a reel, ready to ship.","inputs":[]}],"facts":["Lucien B. Smith of Kent, Ohio, got the first U.S. barbed wire patent in 1867.","Joseph F. Glidden of DeKalb, Illinois, patented the modern design in 1874 after making his own.","Early farmers in Fresno, California, spent nearly $4,000 to haul in wood for fencing before barbed wire."],"where":[],"whereNote":null,"sources":[{"title":"Bergandi: How barbed wire is made","url":"https://bergandi.com/how-barbed-wire-is-made/"},{"title":"Five Star Metals: Barbed wire making process","url":"https://www.fivestar-metals.com/news/professional-guide-to-high-quality-barbed-wire-making-process.html"},{"title":"Barbed wire","url":"https://en.wikipedia.org/wiki/Barbed_wire"},{"title":"Hot-dip galvanizing","url":"https://en.wikipedia.org/wiki/Hot-dip_galvanizing"},{"title":"Wire drawing","url":"https://en.wikipedia.org/wiki/Wire_drawing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"barley","name":"Barley","kind":"raw","category":"farm","title":"How barley is grown and harvested","url":"https://assemblyline.org/make/barley","stations":3,"upstream":0,"downstream":20,"depth":0,"dek":"Barley is the grain that dominated early Neolithic farms, before wheat took over as the favorite.","answer":"Barley is a cool-season grass sown into tilled land, usually drilled in rows today and once scattered by hand. It grows best at 15 to 20 degrees Celsius with a short season. When the stems and ears turn yellow and the ears droop, a combine harvester cuts it.","aka":["barley farming","malting barley","barley crop"],"inputs":[],"uses":["beer","whiskey","bourbon","scotch","light-beer","non-alcoholic-beer","malted-barley"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["beer","whiskey","bourbon","scotch","light-beer","non-alcoholic-beer","malted-barley","vinegar","corn-flakes","bagel","caramel-color","mayonnaise","ketchup","mustard","hot-sauce","salsa","pickles","cola","rum","soda"],"steps":[{"name":"Drill into tilled land","process":"grow","text":"Seed was traditionally scattered over plowed soil, but in developed countries it is now drilled. Barley likes well-drained ground in full sun, and in dry regions it needs irrigation.","inputs":[]},{"name":"Feed and watch the crop","process":"grow","text":"The crop needs nitrogen, phosphorus and potassium, often supplied as fertilizer, and it is checked for pests and disease before they get serious. It prefers 15 to 20 °C and copes with salty soil better than other cereals.","inputs":[],"spec":"15 to 20 °C"},{"name":"Harvest when the ears droop","process":"harvest","text":"Ripe barley turns yellow and the ears begin to droop. Hand harvesting with sickles or scythes was traditional, and in developed countries combine harvesters now do it.","inputs":[]}],"facts":["Barley was the dominant crop for the first thousand years of the Neolithic, before wheat became common.","Sown in autumn as a cover crop and tilled under in spring, barley can slow weed germination in the soil."],"where":[{"place":"Russia","share":"12% of world output"}],"whereNote":"2024, share of the 142 million tonnes of barley produced worldwide. Australia, Germany and France are secondary producers.","sources":[{"title":"Barley","url":"https://en.wikipedia.org/wiki/Barley"},{"title":"Wheat","url":"https://en.wikipedia.org/wiki/Wheat"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"baseball","name":"Baseball","kind":"product","category":"play","title":"How baseballs are made","url":"https://assemblyline.org/make/baseball","stations":7,"upstream":72,"downstream":0,"depth":8,"dek":"A regulation baseball has 108 double stitches, and its cover is stitched by hand.","answer":"A baseball is a small core of cork and rubber wound tightly in layers of wool yarn, then covered with two figure-eight pieces of white cowhide. Yarn is wound on in several layers. The two leather pieces are sewn together with red thread, using 108 stitches, and the finished ball is weighed and rubbed.","aka":["ball","big league baseball"],"inputs":["rubber","wool-yarn","leather","adhesive","thread","ink"],"uses":[],"grounds":["natural-latex","sulfur","fleece","water","cattle-hide","rock-salt","crude-oil","air","limestone","chromite","soybeans","rapeseed","clay","titanium-ore","iron-ore","corn","sugarcane","natural-gas","coal","trona","bauxite","sugar-beet"],"upstreamSlugs":["rubber","wool-yarn","leather","adhesive","thread","ink","natural-latex","synthetic-rubber","carbon-black","sulfur","fleece","water","cattle-hide","rock-salt","lime","chromium","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","polyester","vegetable-oil","phenolic-resin","titanium-dioxide","pigment","ethanol","naphtha","benzene","ethylene","styrene","crude-oil","air","limestone","chromite","coke","soda-ash","aluminum","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","hydrogen","pet-plastic","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","oxygen","iron-ore","corn","sugarcane","yeast","toluene","natural-gas","coal","carbon-dioxide","trona","petroleum-coke","alumina","p-xylene","ethylene-glycol","molasses","bauxite","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Form the center","process":"mold","text":"A small round core is molded from cork and rubber. The center decides much of how lively the ball is.","inputs":["rubber"]},{"name":"Wind on the yarn","process":"spin","text":"Machines wrap the core with layers of wool yarn, pulling tight. Early balls were hand-wound, and tighter windings with more rubber went further and faster.","inputs":["wool-yarn"]},{"name":"Cut the cover panels","process":"cut","text":"Cowhide is tanned, dyed white and cut into two pieces shaped like figure-eights. Each is formed from two saddle-shaped halves.","inputs":["leather"]},{"name":"Glue the cover on","process":"laminate","text":"The wound ball is coated with cement so the cover will bond to the yarn.","inputs":["adhesive"]},{"name":"Hand-stitch the seams","process":"sew","text":"A worker sews the two panels together with red waxed thread. The raised stitches measure 108 in all, and they affect how the ball flies.","inputs":["thread"]},{"name":"Press and stamp","process":"press","text":"The ball is rolled and pressed to a round shape and stamped with its markings.","inputs":["ink"]},{"name":"Weigh and measure","process":"inspect","text":"A major league ball must weigh between 5 and 5.25 ounces and be 9 to 9.25 inches around.","inputs":[]}],"facts":["During World War II, rubber was banned for non-war goods in the US, so in 1943 baseballs got rubber-like balata shells instead.","Benjamin Shibe, who invented the cork-centered baseball, patented it.","In 2019 Major League Baseball officials said a lower seam profile had probably led to more home runs."],"where":[],"whereNote":null,"sources":[{"title":"Baseball (ball)","url":"https://en.wikipedia.org/wiki/Baseball_(ball)"},{"title":"Cowhide","url":"https://en.wikipedia.org/wiki/Cowhide"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"baseball-bat","name":"Baseball bat","kind":"product","category":"wood-paper","title":"How wooden baseball bats are made","url":"https://assemblyline.org/make/baseball-bat","stations":5,"upstream":21,"downstream":0,"depth":6,"dek":"Major league rules say a bat must be one piece of solid wood, so the stick is turned down from a single chunk.","answer":"A wooden baseball bat is turned from one solid piece of ash, maple, hickory or bamboo. A lathe copies a fixed metal template, so each bat has the same profile. The maker brands the label on the side opposite the best grain, shapes the end of the barrel and finishes the bat with a stain.","aka":["wooden bat","Louisville Slugger","ash bat"],"inputs":["timber","lacquer"],"uses":[],"grounds":["timber","corn","sugarcane","water","natural-gas","crude-oil","air","sulfur","sugar-beet"],"upstreamSlugs":["timber","lacquer","ethanol","acrylic","corn","sugarcane","water","yeast","ethylene","propylene","ammonia","sulfuric-acid","methanol","molasses","naphtha","natural-gas","crude-oil","air","sulfur","sugar-beet","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Select the billet","process":"cut","text":"A straight-grained log is cut into square blanks called billets. Most wooden bats are made of ash, and maple is now the most popular new material. The rules require one piece of solid wood.","inputs":["timber"]},{"name":"Turn on a lathe","process":"machine","text":"The billet spins while a cutter follows a fixed metal template and shaves it into a handle, a barrel and a knob. Bats used to be hand-turned from a template with calibration points, and the profile of Babe Ruth's bat is still used as a template today.","inputs":[]},{"name":"Shape the end","process":"machine","text":"Most bats are given a rounded head. About 30 percent of players prefer a cup-balanced head, with a cup-shaped recess cut into the end of the barrel to move the balance toward the handle.","inputs":[]},{"name":"Brand the label","process":"stamp","text":"The maker's name, a serial number and often a player's signature are branded into the wood. The label goes on the mechanically weaker side, opposite the best face of the grain, so that the ball meets the stronger wood.","inputs":[]},{"name":"Stain and finish","process":"coat","text":"The finished bat is stained in a standard color such as natural, red, black or two-tone blue and white, then given a clear protective finish.","inputs":["lacquer"]}],"facts":["Babe Ruth used a 40-inch, 54-ounce ash bat in 1920 and later had an ounce trimmed off each new set.","The emerald ash borer has killed more than 50 million white ash trees in the eastern United States."],"where":[],"whereNote":null,"sources":[{"title":"Baseball bat","url":"https://en.wikipedia.org/wiki/Baseball_bat"},{"title":"Lumber","url":"https://en.wikipedia.org/wiki/Lumber"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"baseball-cap","name":"Baseball cap","kind":"product","category":"textiles","title":"How baseball caps are made","url":"https://assemblyline.org/make/baseball-cap","stations":6,"upstream":46,"downstream":0,"depth":8,"dek":"A fitted baseball cap is sewn from six triangles of cloth meeting at a button on top.","answer":"A baseball cap is cut from fabric into six panels plus a bill. The front panels are stiffened and often embroidered while still flat. Sewers join the panels into a rounded crown, add eyelets, a sweatband and the bill, and top the crown with a fabric-covered button. A final steam press shapes the finished cap.","aka":["ball cap","snapback","fitted cap"],"inputs":["cotton-fabric","thread","adhesive","polypropylene","button"],"uses":[],"grounds":["water","raw-cotton","corn","crude-oil","natural-gas","air","sulfur","rock-salt","limestone","coal","sugarcane","sugar-beet"],"upstreamSlugs":["cotton-fabric","thread","adhesive","polypropylene","button","cotton-yarn","corn-starch","water","polyester","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","propylene","raw-cotton","corn","pet-plastic","ethylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","naphtha","p-xylene","ethylene-glycol","natural-gas","air","sulfur","benzene","rock-salt","oxygen","carbon-dioxide","toluene","yeast","limestone","coal","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the panels","process":"cut","text":"Fabric is cut into six pie-shaped crown panels. The material is cotton, wool or, in major league caps since 2007, polyester.","inputs":["cotton-fabric"]},{"name":"Embroider the logo","process":"sew","text":"While the front panels are still flat, an embroidery machine stitches the logo into them.","inputs":["thread"]},{"name":"Stiffen the front","process":"laminate","text":"The front panels are lined with a stiff fabric called buckram so the logo stands upright and the crown holds its shape.","inputs":["adhesive"]},{"name":"Sew the crown together","process":"sew","text":"The six sections are stitched into a rounded crown. Metal grommets or fabric eyelets are set in near the top to let air in.","inputs":["thread"]},{"name":"Attach the bill","process":"assemble","text":"A curved bill covered in matching fabric is sewn to the front. It was designed to shade a player's eyes from the sun.","inputs":["polypropylene"]},{"name":"Top with a button and steam","process":"assemble","text":"A button, called a squatchee, covers the point where the panels meet. An adjustable strap goes in the back, then the cap is steam pressed into shape.","inputs":["button"]}],"facts":["The Brooklyn Excelsiors wore the ancestor of the modern baseball cap in 1860, with a long peak and a button on top.","Latex rubber became the stiffening material inside the hat in the 1940s, and the modern baseball cap was born.","Major League Baseball changed its players' standard cap from wool to polyester in 2007."],"where":[],"whereNote":null,"sources":[{"title":"Baseball cap","url":"https://en.wikipedia.org/wiki/Baseball_cap"},{"title":"Button","url":"https://en.wikipedia.org/wiki/Button"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"basketball","name":"Basketball","kind":"product","category":"play","title":"How basketballs are made","url":"https://assemblyline.org/make/basketball","stations":8,"upstream":64,"downstream":0,"depth":8,"dek":"A basketball is an air-tight butyl rubber bladder wrapped in nylon thread and covered in pebbled leather.","answer":"A basketball has three layers. A hollow butyl rubber bladder holds the air. Nylon thread is wound round it for strength and shape, and a cover of leather or composite skin goes on top, pressed with channels and pebbles. The ball is inflated, checked and sold flat or ready to play.","aka":["hoops ball"],"inputs":["synthetic-rubber","nylon","leather","adhesive","air","ink"],"uses":[],"grounds":["air","water","cattle-hide","rock-salt","crude-oil","natural-gas","limestone","chromite","soybeans","rapeseed","clay","titanium-ore","iron-ore","sulfur","corn","sugarcane","coal","trona","bauxite","sugar-beet"],"upstreamSlugs":["synthetic-rubber","nylon","leather","adhesive","air","ink","naphtha","benzene","ethylene","styrene","water","nitric-acid","ammonia","cattle-hide","rock-salt","lime","chromium","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","crude-oil","hydrogen","toluene","natural-gas","limestone","chromite","coke","soda-ash","aluminum","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","oxygen","iron-ore","sulfur","corn","sugarcane","yeast","coal","carbon-dioxide","trona","petroleum-coke","alumina","molasses","bauxite","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mix the butyl rubber","process":"mix","text":"Butyl rubber is a synthetic polymer made of 98 percent isobutylene and 2 percent isoprene. It leaks little air and is tough enough to withstand repeated bounces.","inputs":["synthetic-rubber"]},{"name":"Blow the bladder","process":"mold","text":"Rubber is pressed into a hollow sphere with a valve opening, which will hold the air.","inputs":[]},{"name":"Wind the nylon thread","process":"assemble","text":"Machines wrap the bladder with nylon thread in a crisscross pattern. The windings keep the ball round when it is pumped up.","inputs":["nylon"]},{"name":"Cut the cover panels","process":"cut","text":"Cow leather, or a composite sheet for a cheaper ball, is cut into curved panels, each with a channel pattern.","inputs":["leather"]},{"name":"Press the pebble texture","process":"stamp","text":"Heated plates emboss a fine bumpy surface on the cover panels, giving the ball its grip.","inputs":[]},{"name":"Glue the cover on","process":"laminate","text":"Panels are bonded to the wound bladder, leaving seam channels between them.","inputs":["adhesive"]},{"name":"Inflate and stamp","process":"fill","text":"The ball is pumped up to playing pressure and given its logo and size markings.","inputs":["air","ink"]},{"name":"Bounce-test","process":"inspect","text":"Sample balls are dropped and checked for bounce height, roundness and air loss.","inputs":[]}],"facts":["The NBA tried a composite ball in 2006-07, but after complaints from players it went back to leather midway through the season.","The NBA ball is 29.5 inches in circumference.","Basketballs range from a few inches across, for promotional items, to nearly 2 feet for training balls."],"where":[],"whereNote":null,"sources":[{"title":"Basketball (ball)","url":"https://en.wikipedia.org/wiki/Basketball_(ball)"},{"title":"Rubber ball","url":"https://en.wikipedia.org/wiki/Rubber_ball"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"towel","name":"Bath towel","kind":"product","category":"textiles","title":"How bath towels are made","url":"https://assemblyline.org/make/towel","stations":7,"upstream":34,"downstream":0,"depth":8,"dek":"The loops that make a towel absorbent are extra threads on the loom, bunched up on purpose.","answer":"Terry towels use two warp sheets at once: one held tight for the base, one left loose for the pile. Three picks of weft beat up together and push the slack yarn into loops. Rolls leave the loom for inspection and a continuous J-Box bleacher, then get dyed, washed and air dried before being cut, hemmed and checked one at a time.","aka":["terry towel","bath sheet","terrycloth"],"inputs":["cotton-yarn","water","hydrogen-peroxide","pigment","thread"],"uses":[],"grounds":["water","raw-cotton","air","iron-ore","sulfur","natural-gas","titanium-ore","crude-oil","rock-salt","coal","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["cotton-yarn","water","hydrogen-peroxide","pigment","thread","raw-cotton","hydrogen","air","iron-ore","titanium-dioxide","carbon-black","sulfur","polyester","natural-gas","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","crude-oil","pet-plastic","rock-salt","coal","p-xylene","ethylene","ethylene-glycol","naphtha","carbon-dioxide","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Prepare two warps","process":"spin","text":"Pile and ground yarns both go through warping, sizing and drawing-in. Better fibers and low-twist yarns go in the pile for absorbency, while coarser two-ply yarns make a strong ground.","inputs":["cotton-yarn"]},{"name":"Weave the loop pile","process":"weave","text":"One warp runs at normal tension and one loose. Two picks go in with a light beat and a small gap left, then a heavy third beat drives all three home and the loose warp buckles up into loops.","inputs":[]},{"name":"Inspect the gray rolls","process":"inspect","text":"Staff check the first towels on and off the loom against the weaving plan. Rolls are cut to the specification sheet and looked over in an inspection room before going on.","inputs":[]},{"name":"Bleach in a J-Box","process":"wash","text":"A continuous J-Box machine treats the rolls with hydrogen peroxide and caustic recipes at a set speed and reaction time. Washing machines then remove every trace of chemicals.","inputs":["water","hydrogen-peroxide"]},{"name":"Dye the rolls","process":"dye","text":"Dried, uncut rolls go to the dye house for color, then get washed again to remove loose dye and dried on an air-drying machine.","inputs":["water","pigment"]},{"name":"Cut and hem","process":"sew","text":"Finishing opens the rolls, cuts them to the instruction sheet and stitches the edges of each towel.","inputs":["thread"]},{"name":"Inspect and pack","process":"package","text":"An inspector at each table checks both sides and a senior inspector passes it for labeling. Rejected pieces are kept apart, and holes and broken ends are among the common faults.","inputs":[]}],"facts":["The modern terrycloth towel is associated with the city of Bursa, Turkey, in the 17th century.","Towels did not become affordable until the 19th century, when the cotton trade and mechanization made terry towelling available by the yard.","The Greek geographer Strabo described asbestos towels that were cleaned by placing them in a fire."],"where":[],"whereNote":null,"sources":[{"title":"Textile School: Terry towels, fabrics that can absorb large amounts of water","url":"https://www.textileschool.com/3211/terry-towels-fabrics-that-can-absorb-large-amounts-of-water/4/"},{"title":"Online Clothing Study: Towel manufacturing overview","url":"https://www.onlineclothingstudy.com/2012/08/towel-manufacturing-overview.html"},{"title":"Towel","url":"https://en.wikipedia.org/wiki/Towel"},{"title":"Cotton","url":"https://en.wikipedia.org/wiki/Cotton"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bauxite","name":"Bauxite","kind":"raw","category":"ground","title":"How bauxite is mined","url":"https://assemblyline.org/make/bauxite","stations":5,"upstream":0,"downstream":165,"depth":0,"dek":"Bauxite lies so close to the surface that miners often only have to scrape the soil off.","answer":"Bauxite usually lies near the surface, so a mine opens by clearing the ground. Crews take out the trees, peel off topsoil and overburden, then break the ore by drilling, blasting or bulldozing and truck it to a crusher. Pieces of about 7.5 cm go to an alumina refinery by belt, rail or ship, and the soil later goes back on the pit.","aka":["aluminum ore"],"inputs":[],"uses":["alumina","gallium"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["alumina","gallium","aluminum","smartphone-glass","laminate-floor","spark-plug","led","deodorant","lipstick","microchip","led-bulb","oled-screen","lithium-ion-cell","ev-battery","smartphone","laptop","hard-drive","solid-state-drive","solar-cell","solar-panel","refrigerator","washing-machine","satellite","pencil","aluminum-foil","brass","cobalt","chromium","nonstick-pan","aluminum-can","mirror","skyscraper","car","electric-car","car-engine","airplane","rocket","bicycle","motorcycle","skateboard","drum-kit","pencil-eraser","pressure-cooker","toaster","air-conditioner","ceiling-fan","office-chair","ski","yo-yo","toy-car","eyeshadow","asthma-inhaler","prosthetic-leg","wheelchair","ladder","double-glazed-window","aluminum-window-frame","subway-train","sailboat","suitcase","smartwatch","microphone","camera-lens","vinyl-record","compact-disc","game-console","graphics-card","vanadium","newspaper","zipper","n95-mask","lcd-screen","television","computer-mouse","pinball-machine","e-reader","remote-control","hearing-aid","pacemaker","thermometer","credit-card","computer-keyboard","drone","airbag","wireless-earbuds","phone-charger","usb-cable","digital-camera","wifi-router","inkjet-printer","electric-toothbrush","toothpaste","aspirin","condom","aa-battery","wristwatch","faucet","padlock","tire","electric-guitar","trumpet","ballpoint-pen","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","light-switch","power-outlet","leather-belt","handbag","flag","hip-implant","turbine-blade","tungsten-carbide","stent","stainless-steel","safety-pin","razor-blade","ice-skates","dumbbell","wrench","nichrome","leather","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","locomotive","down-jacket","raincoat","backpack","jeans","jet-engine","saw-blade","syringe","electric-kettle","kitchen-knife","fork","elevator","thermos","water-bottle","blender","dishwasher","golf-club","baseball","basketball","tennis-racket","football","winter-gloves","wallet","hiking-boots","high-heels","leather-shoe"],"steps":[{"name":"Clear the land","process":"mine","text":"Surveys map plants, animals and heritage sites first. Trees and vegetation then come off, and crews collect seeds and saplings for regrowing the site afterward.","inputs":[]},{"name":"Strip soil and overburden","process":"mine","text":"Topsoil is scraped away and stored, followed by the secondary layer known as overburden. Scrapers and small excavators expose the hard caprock on top of the ore.","inputs":[]},{"name":"Break and load the ore","process":"mine","text":"Caprock may need blasting, or scrapers may be enough. Excavators or loaders fill haul trucks with ore. Several pits run at once so the blend stays at a consistent grade.","inputs":[]},{"name":"Crush for transport","process":"crush","text":"A vibrating screen drops out fines while a jaw crusher breaks the big rocks, and sizers reduce everything further. Some mines also run wash plants, a simple step that removes clay. Conveyors, rail or ships then carry the ore to a refinery.","inputs":[],"spec":"about 7.5 cm"},{"name":"Refill and replant","process":"mine","text":"Pit edges get smoothed, and overburden and topsoil go back on. Logs and rocks set aside during clearing return too, giving animals shelter and nesting sites.","inputs":[]}],"facts":["Between 70% and 80% of the dry bauxite mined worldwide becomes alumina first and then aluminum.","The waste from refining bauxite is a red sludge called red mud, with a pH around 13, about as alkaline as household bleach.","Bauxite is almost always found near the surface with little or no overburden, so strip mining is the usual method."],"where":[{"place":"Guinea","share":"largest producer"},{"place":"Australia","share":"second"},{"place":"China","share":"third"}],"whereNote":"Ranking by bauxite mined, as given in the Wikipedia bauxite article.","sources":[{"title":"Mining: Process (The Aluminium Story)","url":"https://alustory.international-aluminium.org/?p=353"},{"title":"Bauxite Mining (Australian Aluminium Council)","url":"https://aluminium.org.au/?p=218"},{"title":"Bauxite","url":"https://en.wikipedia.org/wiki/Bauxite"},{"title":"Aluminium","url":"https://en.wikipedia.org/wiki/Aluminium"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"beef-jerky","name":"Beef jerky","kind":"product","category":"food","title":"How beef jerky is made","url":"https://assemblyline.org/make/beef-jerky","stations":6,"upstream":12,"downstream":0,"depth":3,"dek":"Jerky dries in a few hours because it is sliced so thin that warm moving air can pull the water out.","answer":"Lean beef is trimmed of fat, sliced into thin strips and soaked in a salty, seasoned marinade. The strips go on screens into large low-temperature ovens with fans, where warm, moving air dries them in a few hours without cooking them. Dried jerky is packed with an oxygen absorber to protect the fat.","aka":["dried beef","biltong-style snack"],"inputs":["cattle","table-salt","sugar","nitrogen"],"uses":[],"grounds":["cattle","rock-salt","seawater","sugarcane","sugar-beet","water","air","limestone"],"upstreamSlugs":["cattle","table-salt","sugar","nitrogen","rock-salt","seawater","sugarcane","sugar-beet","water","lime","air","limestone"],"downstreamSlugs":[],"steps":[{"name":"Trim and slice thin","process":"cut","text":"Fat is cut away, because fat spoils faster than lean. The meat is sliced or pressed thin so it can dry fast without high heat, which would cook it.","inputs":["cattle"]},{"name":"Marinate or rub","process":"mix","text":"Salt goes on first, for flavor, preservation and to pull out moisture. Pepper, garlic, sugar and sauces change the taste. Some makers add sodium nitrite.","inputs":["table-salt","sugar"]},{"name":"Rack the strips","process":"assemble","text":"Raw marinated strips are laid on nylon-coated screens sprayed with a light film of vegetable oil so they lift off easily. The trays go on rolling carts.","inputs":[]},{"name":"Dry in warm moving air","process":"dry","text":"Carts roll into big ovens with many heaters and fans, and exhaust ports carry off the damp air. The combination of fast air and low heat takes the meat down to the target moisture within a few hours.","inputs":[],"spec":"smoking, if used, stays under 70 °C"},{"name":"Test the moisture","process":"inspect","text":"Jerky needs the right ratio of moisture to protein to keep. In the United States, the standard is a moisture-to-protein ratio of 0.75 to 1.","inputs":[]},{"name":"Seal with an oxygen absorber","process":"package","text":"Cooled jerky is packed in bags flushed with nitrogen or under vacuum. A small pouch of iron particles inside takes up leftover oxygen so the fat does not oxidize.","inputs":["nitrogen"]}],"facts":["The word jerky comes from the Quechua word ch'arki, which means dried, salted meat.","Many products sold as jerky are actually chopped and formed meat rather than a single sliced muscle."],"where":[],"whereNote":null,"sources":[{"title":"Beef jerky","url":"https://en.wikipedia.org/wiki/Beef_jerky"},{"title":"Curing (food preservation)","url":"https://en.wikipedia.org/wiki/Curing_(food_preservation)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"beer","name":"Beer","kind":"product","category":"drink","title":"How beer is made","url":"https://assemblyline.org/make/beer","stations":8,"upstream":59,"downstream":0,"depth":9,"dek":"Brewers first turn barley into a sweet porridge, then let yeast eat the sugar and leave alcohol and bubbles behind.","answer":"Beer begins with malted barley, grain that has been soaked, sprouted and kiln-dried. Malt is milled and steeped in hot water, where enzymes turn its starch into sugar. The sweet liquid, called wort, is boiled with hops, cooled, and fed to yeast. The yeast produces alcohol and carbon dioxide, and the beer is matured, filtered and packaged.","aka":["ale","lager","brew"],"inputs":["barley","water","corn","rice","malted-barley","hops","yeast","glass-bottle","aluminum-can","carbon-dioxide"],"uses":[],"grounds":["barley","water","corn","rice","hops","silica-sand","limestone","natural-gas","sugarcane","sugar-beet","rock-salt","trona","crude-oil","coal","air","bauxite","soybeans","rapeseed","clay","titanium-ore","iron-ore","sulfur"],"upstreamSlugs":["barley","water","corn","rice","malted-barley","hops","yeast","glass-bottle","aluminum-can","carbon-dioxide","molasses","silica-sand","soda-ash","limestone","polyethylene","aluminum","ink","epoxy","natural-gas","sugarcane","sugar-beet","rock-salt","ammonia","lime","trona","ethylene","crude-oil","coal","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","phenol","propylene","acetone","chlorine","caustic-soda","air","naphtha","bauxite","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","coke","oxygen","sulfuric-acid","iron-ore","sulfur","benzene","hydrogen","methanol","toluene"],"downstreamSlugs":[],"steps":[{"name":"Sprout and kiln barley","process":"dry","text":"Barley is soaked in water, spread out to germinate, then dried in a kiln with gradually rising heat. The sprouting creates enzymes that will later turn starch into sugar. The finished grain is called malt.","inputs":["barley"],"spec":"about 40 hours of soaking, then 5 days of germination"},{"name":"Mill and steep","process":"mix","text":"Malt is crushed to expose the starchy core and mixed with hot water in a mash tun. Enzymes in the malt break the starch down into fermentable sugars. Brewers often add rice or corn as cheaper adjuncts.","inputs":["water","corn","rice","malted-barley"],"spec":"60–70 °C for 1 to 2 hours"},{"name":"Drain the sweet wort","process":"separate","text":"Wort is strained through the bed of spent grain in a lauter tun. Hot water is sprayed over the grain to rinse out the remaining sugar. Animal feed is the usual fate of the grains left behind.","inputs":[]},{"name":"Boil with hops","process":"cook","text":"The wort is boiled in a large kettle with hops. The boil sterilizes the liquid, stops the enzymes and extracts bitterness and aroma. A whirlpool afterward gathers the solid particles into a cone in the middle.","inputs":["hops"]},{"name":"Crash-cool the wort","process":"chill","text":"A plate heat exchanger cools the hot wort fast. Yeast dies above 60 °C, so the liquid has to drop to a safe temperature before it goes into the fermenter.","inputs":[]},{"name":"Feed it to yeast","process":"ferment","text":"Yeast is added, or pitched, and begins to eat the sugars, producing alcohol and carbon dioxide. Ale yeast works warm, at 15 to 20 °C, while lager yeast works cooler, at around 10 °C.","inputs":["yeast"],"spec":"ale: 15–20 °C; lager: about 10 °C"},{"name":"Mature the beer","process":"chill","text":"After fermentation the beer rests in a conditioning tank, from a week to several months. Rough flavors fade and the taste smooths out. Lagers are held near freezing for weeks.","inputs":[]},{"name":"Filter and package","process":"fill","text":"The beer is filtered, carbonated to the right level and filled into bottles, cans or kegs. Brown glass bottles protect it from light.","inputs":["glass-bottle","aluminum-can","carbon-dioxide"]}],"facts":["Archaeological evidence of cereal-based brewing has been found in Raqefet Cave in present-day Israel.","Copper has long been the favored metal for brew kettles because bubbles do not cling to it, so it heats the wort evenly.","The Joseph Schlitz Brewing Company began using brown bottles in 1912 to protect beer from light.","A clear Sumerian prayer, the Hymn to Ninkasi, doubled as a way to remember the beer recipe."],"where":[],"whereNote":null,"sources":[{"title":"Beer","url":"https://en.wikipedia.org/wiki/Beer"},{"title":"Brewing","url":"https://en.wikipedia.org/wiki/Brewing"},{"title":"Malting","url":"https://en.wikipedia.org/wiki/Malting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"beeswax","name":"Beeswax","kind":"material","category":"chemicals","title":"How beeswax is made and collected","url":"https://assemblyline.org/make/beeswax","stations":5,"upstream":1,"downstream":5,"depth":1,"dek":"A kilogram of wax costs the bees 6.66 to 8.80 kilograms of honey, by one 1946 estimate.","answer":"Worker bees secrete wax as tiny scales from glands on their abdomens, and build honeycomb from it. Beekeepers collect the cappings sliced off cells at extraction time, plus old and surplus comb. That material is melted and filtered to separate wax from debris, then cast into blocks.","aka":["cera alba","bees wax","candle wax"],"inputs":["honeycomb"],"uses":["gold-ring","jelly-beans","candy-coated-chocolate","licorice","bronze-statue"],"grounds":["honeycomb"],"upstreamSlugs":["honeycomb"],"downstreamSlugs":["gold-ring","jelly-beans","candy-coated-chocolate","licorice","bronze-statue"],"steps":[{"name":"Let the bees build comb","process":"grow","text":"Workers chew their secreted wax scales into the comb cells where honey and young bees are kept.","inputs":[]},{"name":"Collect cappings and old comb","process":"harvest","text":"Beeswax comes from cappings cut off the cells during honey extraction, from scrapped old comb, and from burr and brace comb trimmed from a hive.","inputs":["honeycomb"]},{"name":"Melt the comb out","process":"melt","text":"Wax melts at a low 62 to 64 °C. Heating above 85 °C discolors it, so makers keep it gentle.","inputs":[],"spec":"melts at 62 to 64 °C"},{"name":"Strain out the debris","process":"separate","text":"Molten wax is filtered to leave behind honey residue, pollen and propolis. The wax color ranges from nearly white to brown, depending on purity and flowers.","inputs":[]},{"name":"Pour into blocks","process":"cast","text":"The clean liquid wax is poured into molds and cooled into cakes. These are sold to makers of candles, polishes and cosmetics.","inputs":[]}],"facts":["Beeswax melts so low, at 62 to 64 °C, that heating it past 85 °C is already enough to discolor it.","One kilogram of wax is enough comb to store about 22 kilograms of honey."],"where":[{"place":"India","share":"38% of world production"}],"whereNote":"2020 world beeswax production of 62,116 tonnes (Wikipedia).","sources":[{"title":"Beeswax","url":"https://en.wikipedia.org/wiki/Beeswax"},{"title":"Carnauba wax","url":"https://en.wikipedia.org/wiki/Carnauba_wax"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"benzene","name":"Benzene","kind":"material","category":"chemicals","title":"How benzene is made","url":"https://assemblyline.org/make/benzene","stations":5,"upstream":7,"downstream":283,"depth":4,"dek":"Benzene was once a by-product of making coke for steel. Plastics outgrew that supply by the 1950s.","answer":"Benzene is a flammable liquid hydrocarbon that chemical plants turn into plastics, resins and dyes. Until World War II most came from coke ovens. Today refineries make it by catalytic reforming of naphtha, and some from steam crackers. Benzene is a carcinogen, so plants handle it in closed systems.","aka":["benzol","C6H6"],"inputs":["naphtha","hydrogen","toluene"],"uses":["polystyrene","abs-plastic","nylon","synthetic-rubber","phenol","spandex","styrene","acetone"],"grounds":["crude-oil","water","natural-gas","coal"],"upstreamSlugs":["naphtha","hydrogen","toluene","crude-oil","water","natural-gas","coal"],"downstreamSlugs":["polystyrene","abs-plastic","nylon","synthetic-rubber","phenol","spandex","styrene","acetone","surfboard","bike-helmet","ballpoint-pen","polystyrene-foam","foam-cup","smoke-detector","compact-disc","inkjet-printer","lipstick","hearing-aid","thermometer","lego-brick","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","snowboard","action-figure","harmonica","globe","suitcase","high-heels","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","e-reader","graphics-card","remote-control","electric-toothbrush","toothbrush","mascara","drone","tire","airbag","guitar","violin","basketball","velcro","dishwasher","office-chair","roller-skates","tennis-racket","volleyball","kite","fashion-doll","ukulele","drumstick","eyeshadow","dental-floss","aluminum-window-frame","underwear","leggings","swimsuit","down-jacket","raincoat","handbag","backpack","hiking-boots","flag","socks","carpet","zipper","rope","syringe","rubber","nitrile-glove","chewing-gum","golf-ball","pencil-eraser","flip-flops","rubber-boots","aspirin","acetaminophen","polycarbonate","epoxy","billiard-ball","brake-pad","phenolic-resin","shoelace","eyeglass-frame","cellulose-acetate","car","electric-car","bicycle","motorcycle","jeans","vacuum-cleaner","electric-kettle","pencil","shipping-container","tennis-ball","baseball","soccer-ball","ski","golf-club","football","cricket-bat","dumbbell","treadmill","wheelchair","ladder","wheelbarrow","fire-extinguisher","loudspeaker","sneaker","leather-shoe","umbrella","led-bulb","eyeglass-lens","sunglasses","blender","smartwatch","digital-camera","camera-lens","adhesive","printed-circuit-board","wind-turbine","electric-motor","rebar","aluminum-can","airplane","fishing-rod","prosthetic-leg","ink","photoresist","dice","adhesive-bandage","credit-card","duct-tape","ev-battery","nail","insulation","popcorn","windshield","skateboard","piano","drum-kit","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","clear-tape","staple","sofa","ice-skates","dartboard","chess-set","board-game","jigsaw-puzzle","cello","snow-globe","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","sailboat","dress-shirt","suit","wallet","microphone","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","baseball-cap","mattress","diaper","pacemaker","smartphone","hard-drive","solid-state-drive","microwave-oven","washing-machine","satellite","rocket","locomotive","elevator","ceiling-fan","refrigerator","air-conditioner","subway-train","concrete","skyscraper","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","plastic-bag","tin-can","paper-cup","wallpaper","marker-pen","highlighter","frisbee","trading-cards","candy-coated-chocolate","floor-tile","vinyl-floor","vinyl-record","newspaper","banknote","t-shirt","microchip","memory-chip","lcd-screen","indium-tin-oxide","fireworks","plastic-wrap","cake-mix","hair-dye","tampon","soap","toothpaste","detergent","paperclip","donut","corn-flakes","cotton-candy","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","cough-syrup","light-switch","facial-tissue","paint","condensed-milk","baby-formula","coconut-milk","canned-soup","oled-screen","aa-battery","candy-cane","scissors","mirror","container-ship","water-bottle","water-heater","bowling-ball","toy-car","coil-spring","hammer","gas-cylinder","neon-sign","suspension-bridge-cable","leather-belt","toffee","padlock"],"steps":[{"name":"Reform naphtha over a catalyst","process":"react","text":"A refinery blends a naphtha cut with recycled hydrogen and passes it over a catalyst. Straight-chain molecules curl into rings and shed hydrogen, so the unit makes more hydrogen than it takes in.","inputs":["naphtha"]},{"name":"Crack naphtha for more","process":"react","text":"Steam crackers that make ethylene and propylene also yield a benzene-rich liquid, which joins the stream from the reformer.","inputs":["naphtha"]},{"name":"Draw off the aromatics","process":"separate","text":"The aromatic products are taken out of the reformate stream. They arrive as a mixture of benzene, toluene and xylenes.","inputs":[]},{"name":"Convert toluene to benzene","process":"react","text":"Toluene from the mixture can be turned into more benzene by stripping a methyl group with hydrogen. This hydrogen-heavy step also leaves methane.","inputs":["hydrogen","toluene"]},{"name":"Distill to pure product","process":"refine","text":"Final distillation separates benzene from its neighbors in the mixture. The pure liquid is stored and shipped in closed tanks.","inputs":[]}],"facts":["Charles Mansfield isolated benzene from coal tar in 1845 and began industrial-scale production four years later.","In 1929 Kathleen Lonsdale used X-ray diffraction to confirm that the benzene ring is a flat hexagon.","Benzene is partly responsible for the smell of gasoline."],"where":[],"whereNote":null,"sources":[{"title":"Benzene","url":"https://en.wikipedia.org/wiki/Benzene"},{"title":"Para-xylene","url":"https://en.wikipedia.org/wiki/Para-xylene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bicycle","name":"Bicycle","kind":"product","category":"machines","title":"How bicycles are made","url":"https://assemblyline.org/make/bicycle","stations":8,"upstream":88,"downstream":0,"depth":10,"dek":"There are more than a billion bicycles, and the basic diamond-frame design has barely changed since 1885.","answer":"A bicycle is a welded frame of steel, aluminum or carbon fiber tubes, two wheels, and a chain drive. Tubes are cut and joined, the frame painted, and wheels are laced with steel spokes. Workers then add the chain, gears, brakes and handlebars, and tune the machine before it is boxed.","aka":["bike","pedal cycle","safety bicycle"],"inputs":["steel","aluminum","carbon-fiber","paint","steel-wire","ball-bearing","tire"],"uses":[],"grounds":["crude-oil","coal","air","water","natural-latex","sulfur","iron-ore","limestone","dolomite","manganese-ore","natural-gas","bauxite","titanium-ore","quartz","timber","rock-salt","zinc-ore","copper-ore","lead-ore","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["steel","aluminum","carbon-fiber","paint","steel-wire","ball-bearing","tire","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","crude-oil","coal","petroleum-coke","alumina","propylene","ammonia","air","water","titanium-dioxide","pigment","acrylic","tin-can","sheet-steel","synthetic-rubber","natural-latex","carbon-black","sulfur","brass","nylon","polyester","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","bauxite","caustic-soda","naphtha","titanium-ore","chlorine","methanol","tinplate","lacquer","ink","zinc","benzene","ethylene","styrene","copper","lead","tin","nitric-acid","pet-plastic","quartz","charcoal","timber","rock-salt","hydrogen","ethanol","vegetable-oil","phenolic-resin","zinc-ore","toluene","copper-ore","lead-ore","tin-ore","p-xylene","ethylene-glycol","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","carbon-dioxide","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the frame tubes","process":"cut","text":"Tubes are cut to length and mitered to fit one another. Many are butted, meaning the walls are thicker at the ends where the stress is highest.","inputs":["steel","aluminum"]},{"name":"Join the triangles","process":"weld","text":"Tubes are welded or brazed into a front triangle of head tube, top tube, down tube and seat tube, with a rear triangle behind it. Carbon frames are instead laid up in resin.","inputs":["carbon-fiber"]},{"name":"Paint the frame","process":"coat","text":"Frames are cleaned, primed and painted, usually in a baking oven, then covered with a clear coat and decals.","inputs":["paint"]},{"name":"Lace the wheels","process":"assemble","text":"Steel spokes are threaded from the hub to the rim and tightened until the wheel is true and round.","inputs":["steel-wire","aluminum","ball-bearing"]},{"name":"Mount the tires","process":"assemble","text":"A tire and an inner tube, or a tubeless sealing system, are put on each rim and inflated.","inputs":["tire"]},{"name":"Fit the drivetrain","process":"assemble","text":"Pedals turn the cranks and chainring. A chain carries power to the rear sprockets, and a derailleur shifts it between them to change gear.","inputs":["steel"]},{"name":"Add brakes and cables","process":"assemble","text":"Brake calipers, levers and cables or hoses are fitted, along with handlebars, saddle and seat post.","inputs":["steel-wire"]},{"name":"Tune and test","process":"inspect","text":"A mechanic adjusts the gears and brakes and checks the wheels, then rides the bicycle or spins it on a stand before it is boxed.","inputs":[]}],"facts":["By the early 21st century there were more than 1 billion bicycles in the world.","Alloy steels came into use for better frames in the late 1930s, and aluminum welding techniques improved enough by the 1980s for aluminum frames to become common.","Most bicycles use a derailleur system, with 5 to 12 sprockets on the back wheel and two or three chainrings at the pedals."],"where":[],"whereNote":null,"sources":[{"title":"Bicycle","url":"https://en.wikipedia.org/wiki/Bicycle"},{"title":"Bicycle frame","url":"https://en.wikipedia.org/wiki/Bicycle_frame"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bike-helmet","name":"Bike helmet","kind":"product","category":"play","title":"How bike helmets are made","url":"https://assemblyline.org/make/bike-helmet","stations":7,"upstream":38,"downstream":0,"depth":8,"dek":"A bike helmet saves a head by crushing itself. Its foam liner is made to collapse in a crash.","answer":"A bike helmet is a liner of expanded polystyrene foam, often with a thin plastic shell. Polystyrene beads are expanded with steam in a mold shaped like the helmet. A shell of polycarbonate is fused on, and vents, straps, buckles and comfort pads are added. Samples are crash-tested against safety standards.","aka":["cycling helmet","bicycle helmet"],"inputs":["polystyrene","polycarbonate","nylon","thread","polyurethane"],"uses":[],"grounds":["water","crude-oil","natural-gas","air","rock-salt","coal","sulfur","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["polystyrene","polycarbonate","nylon","thread","polyurethane","naphtha","ethylene","benzene","styrene","phenol","propylene","acetone","caustic-soda","chlorine","nitric-acid","ammonia","polyester","water","crude-oil","hydrogen","natural-gas","toluene","air","rock-salt","sulfuric-acid","pet-plastic","coal","sulfur","p-xylene","ethylene-glycol","oxygen","carbon-dioxide","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Expand the foam beads","process":"mold","text":"Small polystyrene beads that contain a blowing agent are heated with steam. They puff up to many times their size and fuse into a rigid foam.","inputs":["polystyrene"]},{"name":"Mold the liner","process":"mold","text":"Beads fill a steel mold in the shape of the helmet, with channels for ventilation. When heated, they weld themselves into a single piece of foam.","inputs":[]},{"name":"Form the outer shell","process":"mold","text":"A thin sheet of polycarbonate is vacuum-formed into a shell, or placed in the mold so the foam bonds to it. The shell helps the helmet slide instead of snagging on the road.","inputs":["polycarbonate"]},{"name":"Cut the vents and trim","process":"cut","text":"Edges are trimmed, and any extra vents are cut through the shell. More vents cool the head but remove foam.","inputs":[]},{"name":"Sew the straps","process":"sew","text":"Nylon webbing is sewn into chin straps and fitted with a quick-release buckle.","inputs":["nylon","thread"]},{"name":"Fit pads and the dial","process":"assemble","text":"Foam comfort pads, a retention system and the dial that adjusts the fit go in.","inputs":["polyurethane"]},{"name":"Crash-test samples","process":"inspect","text":"Sample helmets are dropped on anvils while instrumented heads measure the force. Under US and European standards, a pass depends on keeping acceleration to the head below a limit.","inputs":[]}],"facts":["The Bell Biker, released in 1975, was the first commercially successful purpose-designed bicycle helmet, with a polystyrene liner and a hard shell.","Both the CPSC and EN 1078 standards measure only straight-line acceleration and ignore rotation.","In the US, the Snell Memorial Foundation was set up to create standards for motorcycle and auto racing helmets."],"where":[],"whereNote":null,"sources":[{"title":"Bicycle helmet","url":"https://en.wikipedia.org/wiki/Bicycle_helmet"},{"title":"Expanded polystyrene","url":"https://en.wikipedia.org/wiki/Expanded_polystyrene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"billiard-ball","name":"Billiard ball","kind":"product","category":"play","title":"How billiard balls are made","url":"https://assemblyline.org/make/billiard-ball","stations":9,"upstream":61,"downstream":0,"depth":10,"dek":"Pool balls were once elephant ivory, and an 1869 substitute mixed nitrocellulose, camphor and ground cattle bone.","answer":"Modern pool balls are cast from phenolic resin, a hard thermoset plastic. Liquid resin is poured into molds, cured with heat, stripped of its casting gate and then machined and polished until each ball hits the right weight, diameter and roundness. At Aramith's Belgian plant the whole run takes thirteen steps and up to 23 days, and every ball gets a final check by hand.","aka":["pool ball","snooker ball","cue ball"],"inputs":["phenol","formaldehyde","pigment","paint"],"uses":[],"grounds":["air","water","iron-ore","sulfur","crude-oil","natural-gas","titanium-ore","coal","rock-salt","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","limestone","dolomite","manganese-ore","quartz","timber","sugar-beet"],"upstreamSlugs":["phenol","formaldehyde","pigment","paint","benzene","propylene","air","methanol","water","iron-ore","titanium-dioxide","carbon-black","sulfur","acrylic","tin-can","naphtha","hydrogen","toluene","crude-oil","natural-gas","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","ammonia","tinplate","lacquer","ink","coal","rock-salt","steel","tin","ethanol","vegetable-oil","phenolic-resin","pig-iron","magnesium","steel-scrap","lime","manganese","argon","tin-ore","corn","sugarcane","yeast","ethylene","soybeans","rapeseed","hexane","clay","limestone","dolomite","silicon","propane","manganese-ore","molasses","quartz","charcoal","timber","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Make the resin","process":"react","text":"Phenolic resin sets hard and does not melt again. Saluc, maker of Aramith balls, formulates its own in a chemical plant on site, since the resin decides how the ball rebounds and wears. Color goes into the mix as dyes or pigments.","inputs":["phenol","formaldehyde","pigment"]},{"name":"Pour into molds","process":"cast","text":"The liquid resin is poured at normal pressure with a sprue facing up, so that bubbles inside can rise and escape. A 1938 patent warms its molds and draws a vacuum for a few minutes to clear surface voids.","inputs":[]},{"name":"Cure with heat","process":"heat-treat","text":"Curing sets the resin to a first hardness. The 1938 patent bakes its cast stock for four days at about 80 °C before any machining.","inputs":[],"spec":"up to 23 days for the whole process at one maker"},{"name":"Grind off the gate","process":"grind","text":"The poured sprue leaves a knob standing on the sphere. The traditional fix is to hold the ball against an emery wheel, which is slow and can leave it out of round, and one Chinese design uses a collet cutter instead.","inputs":[]},{"name":"Machine slightly oversize","process":"machine","text":"In the 1938 patent, the hardened stock is first machined to balls about 0.080 inch bigger than final size, which leaves stock to remove after the next step.","inputs":[]},{"name":"Harden the surface","process":"heat-treat","text":"More heating hardens the outer layer. That patent packs its balls in sawdust for three days. Aramith says its better grades go through several hardening steps that leave a translucent vitrified surface.","inputs":[]},{"name":"Turn to true size","process":"machine","text":"Balls are cut down to final diameter and roundness with computer-controlled tools. Pool rules allow a diameter of 2 and a quarter inches, plus or minus 0.005 inch.","inputs":[]},{"name":"Polish the surface","process":"grind","text":"Polishing brings up the glassy finish. Aramith says a finer resin grain holds that polish for longer.","inputs":[]},{"name":"Mark and check","process":"inspect","text":"Numbers and colors go on, and balls are judged on density, balance, diameter, roundness, color, polish and brilliance. Automated checks run throughout, and a person still checks every ball. Top sets are sorted so all balls fall within 1.5 grams.","inputs":["paint"]}],"facts":["Elephant ivory stayed the preferred material for billiard balls from 1627 or earlier into the early twentieth century.","One maker says nearly 80 percent of the world's billiard balls come from a single small village in Belgium.","Mass harvesting of camphor for early plastic balls devastated forests in Taiwan."],"where":[],"whereNote":null,"sources":[{"title":"US2223394A, Billiard ball and method of manufacture","url":"https://patents.google.com/patent/US2223394A/en"},{"title":"CN203228335U, Sprue removal equipment for phenolic resin billiard ball","url":"https://patents.google.com/patent/CN203228335U/en"},{"title":"The story behind Aramith","url":"https://aramith.com/?p=122"},{"title":"The Undisputed Ball, Aramith","url":"https://aramith.com/?p=77"},{"title":"Setting the Record Straight on Aramith Phenolic Balls, AZBilliards","url":"https://azbilliards.com/?p=58188"},{"title":"Billiard ball","url":"https://en.wikipedia.org/wiki/Billiard_ball"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"biodiesel","name":"Biodiesel","kind":"product","category":"chemicals","title":"How biodiesel is made","url":"https://assemblyline.org/make/biodiesel","stations":5,"upstream":10,"downstream":2,"depth":4,"dek":"Biodiesel chemistry is older than the diesel engine. Vegetable oil was first split this way in 1853.","answer":"Biodiesel is made from vegetable oil, animal fat or used cooking grease by transesterification. The fat reacts with methanol and a catalyst, which swaps the glycerol backbone for methyl groups and leaves fatty acid methyl esters. About 100 kilograms of glycerol come off for every tonne of fuel.","aka":["FAME","B20","fatty acid methyl ester"],"inputs":["vegetable-oil","methanol"],"uses":["diesel"],"grounds":["soybeans","rapeseed","water","clay","natural-gas","crude-oil"],"upstreamSlugs":["vegetable-oil","methanol","soybeans","rapeseed","hexane","water","clay","natural-gas","crude-oil","hydrogen"],"downstreamSlugs":["diesel","locomotive"],"steps":[{"name":"Filter the fat or oil","process":"separate","text":"Vegetable oil, animal fat or frying oil is strained and cleaned. Free water and solids would upset the reaction.","inputs":["vegetable-oil"]},{"name":"Prepare the methoxide","process":"mix","text":"Methanol is the cheapest alcohol, so most plants use it. It is converted to sodium methoxide, which drives the reaction.","inputs":["methanol"]},{"name":"React oil with alcohol","process":"react","text":"The oil and the methoxide are stirred together in a reactor. Each fat molecule splits into long-chain methyl esters and free glycerol.","inputs":[]},{"name":"Let the glycerol settle","process":"separate","text":"Two layers form as the mixture rests. Glycerol sinks, and the lighter esters, which are the biodiesel, float on top.","inputs":[]},{"name":"Wash and dry the fuel","process":"wash","text":"The biodiesel layer is washed to remove leftover catalyst and soap, then dried. It is tested against standards before it is blended with regular diesel.","inputs":[]}],"facts":["For every tonne of biodiesel, about 100 kilograms of glycerol are produced.","Rudolf Diesel never designed his engine for peanut oil, though one ran on it at the 1900 Paris Exposition.","Blends under 20 percent biodiesel work in diesel equipment with little or no modification."],"where":[],"whereNote":null,"sources":[{"title":"Biodiesel","url":"https://en.wikipedia.org/wiki/Biodiesel"},{"title":"Methanol","url":"https://en.wikipedia.org/wiki/Methanol"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tea","name":"Black tea","kind":"product","category":"drink","title":"How black tea is made","url":"https://assemblyline.org/make/tea","stations":7,"upstream":1,"downstream":1,"depth":1,"dek":"Black tea is just fresh leaf left to rust in a controlled way, which is why its flavor keeps for years.","answer":"Black tea is made from the young leaves of one shrub. After picking, the leaves are withered to lose water, then bruised or rolled so their enzymes meet oxygen and the leaf browns. That oxidation is stopped by hot-air drying. Finally the leaf is sieved into grades from whole leaf to dust.","aka":["red tea","hong cha","CTC tea"],"inputs":["tea-leaves"],"uses":["kombucha"],"grounds":["tea-leaves"],"upstreamSlugs":["tea-leaves"],"downstreamSlugs":["kombucha"],"steps":[{"name":"Pluck the new shoots","process":"harvest","text":"Workers pick the bud and top leaves of the tea bush. Young leaves and buds carry the most caffeine, and the quality of the plucking sets the ceiling on the finished tea.","inputs":["tea-leaves"]},{"name":"Wither on troughs","process":"dry","text":"Leaves are spread on long troughs and air is blown through them, usually overnight. They go limp, lose about 35% of their moisture and start to change slightly.","inputs":[],"spec":"8 to 14 hours"},{"name":"Roll or shred the leaf","process":"crush","text":"Orthodox processing rolls the leaf on a ridged table, which bruises and twists it. The CTC method pushes it through spiked rollers that crush, tear and curl it into tiny pellets, which suits tea bags.","inputs":[]},{"name":"Oxidize in humid air","process":"react","text":"Bruising frees enzymes and sap, and the leaf starts to oxidize in cool, humid air. Polyphenols in the leaf turn into the compounds that give black tea its color and strength. This is often called fermentation, but no microbes are involved.","inputs":[],"spec":"45 minutes to 3 hours at 20–30 °C"},{"name":"Fire it dry","process":"bake","text":"Firing in hot air halts the chemistry for good. The leaf turns black and brittle, and loses nearly all its remaining water.","inputs":[]},{"name":"Sieve into grades","process":"separate","text":"Screens sort the leaf into whole leaf, broken, fannings and dust. Fannings and dust have more surface area, so they brew fast, and they are what goes into most tea bags.","inputs":[]},{"name":"Blend and pack","process":"package","text":"Many black teas are blends of different estates. They are weighed into bags, tins or sacks for shipping.","inputs":[]}],"facts":["Compressed bricks of black tea served as a form of de facto money in Mongolia, Tibet and Siberia into the 19th century.","The CTC method was developed by William McKercher in 1930.","Black tea keeps its flavor for several years, while green tea usually loses its flavor within a year."],"where":[],"whereNote":null,"sources":[{"title":"Black tea","url":"https://en.wikipedia.org/wiki/Black_tea"},{"title":"Tea processing","url":"https://en.wikipedia.org/wiki/Tea_processing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chalk","name":"Blackboard chalk","kind":"product","category":"minerals","title":"How blackboard chalk is made","url":"https://assemblyline.org/make/chalk","stations":6,"upstream":16,"downstream":0,"depth":5,"dek":"Much classroom chalk is not chalk at all. Gypsum is the cheaper ingredient, and chalk rock is made of ancient plankton shells.","answer":"Most blackboard sticks are cast from gypsum powder, like plaster. Workers oil the holes of a mold plate, and a stirrer whips water, gypsum and any pigment into a slurry for a few seconds. The slurry floods the holes and is scraped level. Once the sticks set slightly firm, the plate pushes them up out of the mold, and they dry at low heat before boxing.","aka":["blackboard chalk","classroom chalk","sidewalk chalk"],"inputs":["gypsum","water","pigment"],"uses":[],"grounds":["gypsum","water","iron-ore","sulfur","titanium-ore","crude-oil","air","rock-salt","coal"],"upstreamSlugs":["gypsum","water","pigment","iron-ore","titanium-dioxide","carbon-black","sulfur","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","crude-oil","air","rock-salt","coal"],"downstreamSlugs":[],"steps":[{"name":"Quarry and grind gypsum","process":"crush","text":"Gypsum or limestone is dug and ground to a fine powder, which reaches the chalk plant ready to measure.","inputs":["gypsum"]},{"name":"Oil the mold plate","process":"coat","text":"A wide brush spreads release oil inside the mold holes, more generously on new molds. The plate cycles up and down so its ejector screws seat properly.","inputs":[]},{"name":"Whip the slurry","process":"mix","text":"Water goes into the bucket first, then the measured gypsum and any color powder. A high-speed stirrer runs 10 to 20 seconds until the slurry is smooth.","inputs":["water","pigment"]},{"name":"Pour and scrape level","process":"cast","text":"A discharge switch lets the slurry flow into every hole, up to 800 on a large plate. A plastic scraper levels the tops so each base comes out flat.","inputs":[]},{"name":"Eject the sticks","process":"mold","text":"Once the sticks feel slightly firm, the plate lifts them 2 to 5 mm, waits a minute or two, then pushes them out completely.","inputs":[]},{"name":"Dry and box","process":"dry","text":"Sticks cure in the sun or an oven held at no more than 55 °C, then go into boxes.","inputs":[]}],"facts":["Chalk rock is made of calcite plates only 0.5 to 4 microns across, which are fragments of plankton shells.","The Cretaceous Period gets its name from creta, the Latin word for chalk.","Carbonate chalk makes larger particles than gypsum chalk, so it is marketed as dustless."],"where":[],"whereNote":null,"sources":[{"title":"Gondor Machinery: Fully automatic chalk making machines","url":"https://gondormachinery.com/everything-you-need-to-know-about-fully-automatic-chalk-making-machines"},{"title":"CN patent 1041214C: Formula and process of wet dust-free chalk","url":"https://patents.google.com/patent/CN1041214C/en"},{"title":"Chalk","url":"https://en.wikipedia.org/wiki/Chalk"},{"title":"Blackboard","url":"https://en.wikipedia.org/wiki/Blackboard"},{"title":"Sidewalk chalk","url":"https://en.wikipedia.org/wiki/Sidewalk_chalk"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bleach","name":"Bleach","kind":"product","category":"body-health","title":"How bleach is made","url":"https://assemblyline.org/make/bleach","stations":7,"upstream":24,"downstream":1,"depth":7,"dek":"Household bleach is just salt water zapped with electricity, then mixed with its own byproduct.","answer":"Household bleach is sodium hypochlorite in water. A plant runs electric current through salty brine, which splits it into chlorine gas, hydrogen and caustic soda. Chlorine is then bubbled into cooled caustic soda solution, which captures it as hypochlorite. The solution is diluted to a 3 to 6 percent strength, checked and bottled.","aka":["household bleach","sodium hypochlorite","chlorine bleach"],"inputs":["rock-salt","water","chlorine","caustic-soda","plastic-bottle"],"uses":["kitchen-sponge"],"grounds":["rock-salt","water","sulfur","air","natural-gas","crude-oil","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["rock-salt","water","chlorine","caustic-soda","plastic-bottle","sulfuric-acid","pet-plastic","sulfur","air","p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","oxygen","carbon-dioxide","crude-oil","hydrogen","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["kitchen-sponge"],"steps":[{"name":"Dissolve the salt","process":"mix","text":"Salt from rock deposits or seawater is dissolved in water to make a saturated brine. The brine is purified to remove calcium and magnesium that would foul the cells.","inputs":["rock-salt","water"]},{"name":"Electrolyze the brine","process":"electrolyze","text":"Brine flows through a cell divided by a membrane. Current pulls chlorine out at one electrode and makes hydrogen and caustic soda at the other. The chlorine-alkali process uses a lot of electricity per tonne of sodium hydroxide.","inputs":[]},{"name":"Collect the products","process":"separate","text":"Chlorine gas, hydrogen and caustic soda leave the cell by separate pipes. Each is a commodity chemical on its own.","inputs":[]},{"name":"React chlorine with lye","process":"react","text":"Chlorine gas is fed into a chilled caustic soda solution, and the two combine into sodium hypochlorite, salt and water.","inputs":["chlorine","caustic-soda"]},{"name":"Dilute to strength","process":"mix","text":"The strong solution is diluted with water until its hypochlorite content falls in the household range. A stabilizer helps it keep for months.","inputs":["water"]},{"name":"Test the batch","process":"inspect","text":"Chemists titrate samples to confirm the strength, since bleach slowly loses potency in light and heat.","inputs":[]},{"name":"Bottle in opaque plastic","process":"fill","text":"Opaque plastic bottles with vented caps are filled and labeled with warnings against mixing bleach with other cleaners.","inputs":["plastic-bottle"]}],"facts":["The chloralkali process uses around 2,500 kWh of electricity per tonne of sodium hydroxide produced.","Household bleach is a dilute 3 to 6 percent solution of sodium hypochlorite, historically called Labarraque's water.","In the 1820s French chemist Antoine-Germain Labarraque showed that chlorine bleach solutions slowed putrefaction, long before germ theory."],"where":[],"whereNote":null,"sources":[{"title":"Bleach","url":"https://en.wikipedia.org/wiki/Bleach"},{"title":"Chloralkali process","url":"https://en.wikipedia.org/wiki/Chloralkali_process"},{"title":"Sodium hypochlorite","url":"https://en.wikipedia.org/wiki/Sodium_hypochlorite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"blender","name":"Blender","kind":"product","category":"machines","title":"How blenders are made","url":"https://assemblyline.org/make/blender","stations":7,"upstream":102,"downstream":0,"depth":10,"dek":"The blender began as a 1922 soda fountain gadget for mixing malted milkshakes.","answer":"Vitamix still assembles most of its blenders by hand. Workers slide units along roller lines and drive screws with electric screwdrivers hanging from above, and a machine leaves the line every 34 seconds. Blendtec populates its control boards on a two-lane line in Orem, Utah. Molded jars, steel blades, motors and gaskets all meet in assembly.","aka":["liquidiser","countertop blender","smoothie maker"],"inputs":["polycarbonate","stainless-steel","printed-circuit-board","electric-motor","copper-wire","silicone","cardboard-box"],"uses":[],"grounds":["water","silica-sand","air","crude-oil","rock-salt","chromite","limestone","nickel-ore","copper-ore","quartz","coal","timber","natural-gas","sulfur","trona","tin-ore","lead-ore","silver-ore","zinc-ore","iron-ore","dolomite","manganese-ore","soybeans","rapeseed","clay","titanium-ore","corn","sugarcane","bauxite","sugar-beet"],"upstreamSlugs":["polycarbonate","stainless-steel","printed-circuit-board","electric-motor","copper-wire","silicone","cardboard-box","phenol","propylene","acetone","caustic-soda","chlorine","steel-scrap","chromium","nickel","oxygen","argon","copper","fiberglass","epoxy","photoresist","solder","sheet-steel","ball-bearing","steel","silicon","methanol","hydrochloric-acid","water","silica-sand","cardboard","ink","adhesive","benzene","air","naphtha","crude-oil","rock-salt","sulfuric-acid","propane","chromite","coke","soda-ash","limestone","aluminum","nickel-ore","copper-ore","phenolic-resin","tin","lead","silver","zinc","steel-wire","pig-iron","magnesium","lime","manganese","quartz","coal","charcoal","timber","natural-gas","hydrogen","wood-pulp","vegetable-oil","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","polyurethane","paraffin-wax","toluene","sulfur","ammonia","carbon-dioxide","trona","petroleum-coke","alumina","formaldehyde","tin-ore","lead-ore","silver-ore","zinc-ore","iron-ore","dolomite","manganese-ore","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","titanium-ore","corn","sugarcane","yeast","ethylene","nitric-acid","bauxite","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the jar and base","process":"mold","text":"Molten plastic is injected into steel molds to make the jar and the housing for the motor. Jars can also be glass or stainless steel.","inputs":["polycarbonate"]},{"name":"Form the blades","process":"forge","text":"Blade sets are shaped from steel, with arms angled to churn food into a whirlpool. Blendtec says it cold-forges its blades.","inputs":["stainless-steel"]},{"name":"Populate the control boards","process":"assemble","text":"Machines load the circuit boards that run speed settings and preset cycles. Blendtec calls this its most critical and time-intensive step. An elevator and overhead conveyor flip each half-finished board and lower it to a second lane for its other side, with no hands involved.","inputs":["printed-circuit-board"]},{"name":"Fit motor and controls","process":"assemble","text":"An electric motor goes in the base, along with the controls and power cord. At Vitamix this is mostly hand work. Electric screwdrivers hang overhead to apply the right torque, and units slide on rollers from one station to the next.","inputs":["electric-motor","copper-wire"]},{"name":"Seal the blade assembly","process":"assemble","text":"A gasket or O-ring sits between the container body and the blade base, so the contents cannot leak.","inputs":["silicone"]},{"name":"Stop at quality gates","process":"inspect","text":"At set points on the Vitamix line, a physical barrier rises and stays up until a group of checks is complete. Each worker also inspects what the previous station did.","inputs":[]},{"name":"Box and ship","process":"package","text":"Blendtec describes small teams that build and box each blender from start to finish. At Vitamix's Strongsville, Ohio plant, about 300 people assemble, pack and ship the machines.","inputs":["cardboard-box"],"spec":"one machine every 34 seconds at Vitamix"}],"facts":["Stephen Poplawski patented his drink mixer in 1922 to make Horlicks malted milkshakes at soda fountains.","Blades create a whirlpool that pulls solids from top to bottom, so low-powered blenders need some liquid to work.","Plastic jars scratch and absorb the smell of food, while glass jars are heavier and more stable."],"where":[],"whereNote":null,"sources":[{"title":"Blender (appliance)","url":"https://en.wikipedia.org/wiki/Blender_(appliance)"},{"title":"Injection moulding","url":"https://en.wikipedia.org/wiki/Injection_moulding"},{"title":"Vitamix Factory Photos: How Vitamix blenders are made","url":"https://joyofblending.com/vitamix-factory-tour/"},{"title":"Buckeye Built: Vitamix spinning strong for nearly 100 years","url":"https://news5cleveland.com/news/buckeye-built/buckeye-built-blender-giant-vitamix-has-been-spinning-strong-for-nearly-100-years"},{"title":"Blendtec Doubles Blender Output with PROMATION-Designed Production Line","url":"https://prnewswire.com/news-releases/blendtec-doubles-blender-output-with-promation-designed-production-line-259934641.html"},{"title":"Where are Blendtec Blenders Made","url":"https://blendtec.com/where-are-blendtec-blenders-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"agave","name":"Blue agave","kind":"raw","category":"farm","title":"How blue agave is grown and harvested","url":"https://assemblyline.org/make/agave","stations":5,"upstream":0,"downstream":3,"depth":0,"dek":"A flower stalk can shoot up a meter a week, so field hands go through and chop them every two weeks or less.","answer":"Blue agave is a spiky succulent raised from shoots taken off a parent plant, so a whole field is about the same age. For years, field hands trim leaves and cut flower stalks so sugar collects in the heart. When the plant tests ripe, a jimador hacks off its leaves with a long-handled coa and the piña goes onto a truck.","aka":["blue agave","Agave tequilana","tequila agave","agave piñas","agave azul"],"inputs":[],"uses":["tequila","dartboard","mezcal"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["tequila","dartboard","mezcal"],"steps":[{"name":"Plant the hijuelos","process":"grow","text":"Fields are set with shoots, called hijuelos, removed from parent plants. The plant favors altitudes above 1,500 metres and sandy soil. Replanting clones this way has cost the crop much of its genetic diversity.","inputs":[]},{"name":"Cut down the quiotes","process":"grow","text":"Flower stalks appear around years five and six and grow fast. Crews walk the rows every two weeks or less to chop them, because a stalk would spend the plant's sugars on seed. The same field hands trim leaves and pull new shoots for transplanting.","inputs":[]},{"name":"Test for ripe sugar","process":"inspect","text":"A ripe heart starts to shrink and takes on a maroon tinge, with red spots on the leaves. Producers now test sugar as well. A Mexican decree of March 2006 requires at least 24% on average across a harvested field. Harvest runs all year, usually six to 12 months after the stalk was cut.","inputs":[],"spec":"at least 24% sugar, field average"},{"name":"Strip it with a coa","process":"harvest","text":"A jimador tips the plant and cuts away its 200 or more spiky leaves with a sharp, long-handled blade. A big plant takes about three to six minutes. The work stays manual, and a good jimador can clear more than a ton in a day.","inputs":[]},{"name":"Truck the piñas out","process":"harvest","text":"Hearts normally weigh 40 to 90 kg and go by truck to the distillery, where they are usually halved or quartered before baking. The cut leaves have no use in the industry beyond an occasional load of compost.","inputs":[],"spec":"40 to 90 kg a heart"}],"facts":["More than 300 million plants are harvested each year in the Tequila region.","Blue agave can reach over 2 metres tall, and its stalk can add another 5 metres.","Nobody can judge the size of a piña until its leaves are off, so two similar plants can give very different hearts."],"where":[],"whereNote":null,"sources":[{"title":"Agave tequilana","url":"https://en.wikipedia.org/wiki/Agave_tequilana"},{"title":"Tequila","url":"https://en.wikipedia.org/wiki/Tequila"},{"title":"Harvesting Agave for Tequila, In Search of the Blue Agave","url":"https://www.ianchadwick.com/tequila/harvesting.htm"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"board-game","name":"Board game","kind":"product","category":"play","title":"How board games are made","url":"https://assemblyline.org/make/board-game","stations":6,"upstream":58,"downstream":0,"depth":10,"dek":"A board game is several products built on separate lines: a mounted board, cut cards, punched tokens and a box.","answer":"A board game is a bundle of parts made on separate lines. The board is printed, laminated and mounted on thick greyboard, then scored so it folds. Cards are printed and cut into decks. Tokens are die-cut from chipboard. Everything is packed into a box with an insert tray and shrink-wrapped.","aka":["tabletop game","board games"],"inputs":["ink","paper","cardboard","adhesive","cardboard-box","plastic"],"uses":[],"grounds":["water","kaolin","limestone","natural-gas","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","timber","rock-salt","coal","sugar-beet"],"upstreamSlugs":["ink","paper","cardboard","adhesive","cardboard-box","plastic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","wood-pulp","kaolin","limestone","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","naphtha","natural-gas","ethylene","propylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","timber","caustic-soda","lime","hydrogen-peroxide","ammonia","methanol","acetone","nitric-acid","hydrogen","benzene","rock-salt","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Print the board","process":"print","text":"Artwork goes on coated paper, which is laminated with a gloss or matte film. Large boards are printed in sheets, then trimmed.","inputs":["ink","paper"]},{"name":"Mount it on greyboard","process":"laminate","text":"The printed sheet is glued to a stiff board 2 or 3 millimeters thick, with a linen-textured backing paper. This is what keeps a big board flat on the table.","inputs":["cardboard","adhesive"]},{"name":"Score and fold it","process":"cut","text":"Folds are built in, as a board can be bigger than the box. Bi-fold boards have one center hinge, tri-fold have two parallel folds, and quad-fold have two perpendicular folds.","inputs":[]},{"name":"Die-cut the tokens","process":"stamp","text":"Tokens and tiles are printed on thick chipboard, laminated, and punched out with a custom die made for that sheet.","inputs":["cardboard","ink"]},{"name":"Cut cards into decks","process":"cut","text":"Printed card sheets are cut into cards and collated into decks, and dice and rulebooks come from their own lines.","inputs":["paper","ink"]},{"name":"Pack into the box","process":"assemble","text":"Parts go into a two-piece rigid box with an insert tray, so nothing shifts in shipping. Many games are then shrink-wrapped.","inputs":["cardboard-box","plastic"]}],"facts":["Possible fragments of Senet boards, argued to be the oldest known board game, date to around 3100 BC.","A quad-fold board folds down to one quarter of its play surface so it can fit a square box.","Tokens come in thicknesses of 1, 1.5 or 2 millimeters of chipboard."],"where":[],"whereNote":null,"sources":[{"title":"Board game printing and manufacturing","url":"https://printninja.com/printing-products/board-game-printing/"},{"title":"Board game","url":"https://en.wikipedia.org/wiki/Board_game"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bolt","name":"Bolt","kind":"product","category":"hardware","title":"How bolts are made","url":"https://assemblyline.org/make/bolt","stations":6,"upstream":28,"downstream":2,"depth":6,"dek":"Before Joseph Whitworth's 1841 proposal for a standard, each nut was made by hand to match one bolt.","answer":"Most bolts are cold-formed from steel wire or bar. A machine cuts a slug, squeezes one end into a hexagonal head, and rolls a thread onto the shank between hardened dies. Strong grades are then heat treated, and many bolts get a zinc coating so they survive rain and rust.","aka":["hex bolt","machine bolt"],"inputs":["steel-wire","zinc"],"uses":["roller-skates","wheelbarrow"],"grounds":["zinc-ore","air","sulfur","water","iron-ore","limestone","dolomite","manganese-ore","natural-gas","coal","quartz","timber","crude-oil"],"upstreamSlugs":["steel-wire","zinc","steel","zinc-ore","air","sulfuric-acid","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","sulfur","water","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","coal","quartz","charcoal","timber","crude-oil"],"downstreamSlugs":["roller-skates","wheelbarrow"],"steps":[{"name":"Cut a slug of wire","process":"cut","text":"Steel wire or bar is sheared into pieces, each long enough to make one bolt. Because the metal is only moved around later, the slug carries exactly the volume of steel the finished bolt needs.","inputs":["steel-wire"]},{"name":"Upset the head","process":"forge","text":"A punch hammers one end of the slug into a head inside a die, without heating the steel first. The grain of the steel flows into the head, which is stronger than a head carved out of a bigger bar.","inputs":[]},{"name":"Roll the thread","process":"roll","text":"The shank is pressed between two threaded dies and the steel flows into the grooves. Rolled threads are stronger than cut ones.","inputs":[]},{"name":"Harden the strong grades","process":"heat-treat","text":"High-strength bolts are heated and quenched, then tempered. The strength class stamped on the head records the result.","inputs":[]},{"name":"Coat in zinc","process":"coat","text":"For outdoor use, bolts are galvanized or electroplated with a layer of zinc that corrodes before the steel does.","inputs":["zinc"]},{"name":"Sort and gauge","process":"inspect","text":"Samples are checked against thread gauges and pulled in test machines, then the batch is counted into boxes.","inputs":[]}],"facts":["Joseph Whitworth proposed a thread standard in 1841 because nuts and bolts had been made in matched pairs that did not fit any others.","The Crystal Palace of 1851 had to go up in 190 days, and interchangeable nuts and bolts worked so well there that Whitworth's standard spread."],"where":[],"whereNote":null,"sources":[{"title":"Bolt (fastener)","url":"https://en.wikipedia.org/wiki/Bolt_(fastener)"},{"title":"Cold heading","url":"https://en.wikipedia.org/wiki/Cold_heading"},{"title":"Threading (manufacturing)","url":"https://en.wikipedia.org/wiki/Thread_rolling"},{"title":"Screw","url":"https://en.wikipedia.org/wiki/Screw"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"book","name":"Book","kind":"product","category":"wood-paper","title":"How books are made","url":"https://assemblyline.org/make/book","stations":6,"upstream":66,"downstream":0,"depth":9,"dek":"Most hardcover books are printed in folded bundles of pages sewn along the fold, which is why they lie flat.","answer":"A printed book starts as big sheets covered in pages, printed on both sides. The sheets are folded into bundles called signatures, gathered in order and sewn or glued into a text block. A rigid case of board covered with cloth or paper is then fastened around it. Perfect-bound paperbacks skip the sewing and rely on glue.","aka":["hardcover","paperback","bound book"],"inputs":["paper","ink","thread","adhesive","cardboard","cotton-fabric"],"uses":[],"grounds":["water","kaolin","limestone","timber","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","raw-cotton","rock-salt","coal","natural-gas","sugar-beet"],"upstreamSlugs":["paper","ink","thread","adhesive","cardboard","cotton-fabric","wood-pulp","water","kaolin","limestone","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyester","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","cotton-yarn","corn-starch","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","ethylene","pet-plastic","propylene","ammonia","methanol","acetone","nitric-acid","hydrogen","raw-cotton","rock-salt","benzene","coal","molasses","naphtha","natural-gas","p-xylene","ethylene-glycol","toluene","sugar-beet","carbon-dioxide"],"downstreamSlugs":[],"steps":[{"name":"Print large sheets","process":"print","text":"Presses print many pages at once on both sides of large sheets of paper. The pages are arranged so they will land in the right order after folding.","inputs":["paper","ink"]},{"name":"Fold into signatures","process":"assemble","text":"Folding machines fold each printed sheet down into a compact bundle, called a signature. When a hardcover is opened in the middle of a signature, the stitching is visible.","inputs":[]},{"name":"Gather and sew the stack","process":"sew","text":"The signatures are collated in order. For the best binding they are stitched through the fold, a method called the gold standard. Machines then glue the sewn signatures at the spine to hold the text block together.","inputs":["thread","adhesive"]},{"name":"Trim the edges","process":"cut","text":"A guillotine shaves the other three sides of the text block so the pages are even and free to turn.","inputs":[]},{"name":"Cover the boards","process":"laminate","text":"Two stiff boards and a spine strip are wrapped in cloth, vinyl, leather or printed paper to make the case. Cotton-based book cloth became common in the nineteenth century.","inputs":["cardboard","cotton-fabric"]},{"name":"Case the text block","process":"assemble","text":"Glued endpapers join the text block to the finished case, and the book is pressed while the glue sets. A paper dust jacket may go around it afterward.","inputs":["adhesive"]}],"facts":["Johannes Gutenberg invented movable type in Europe around 1450, making books quicker and less expensive to produce.","The earliest surviving European bookbinding is the St Cuthbert Gospel of about 700, in red goatskin."],"where":[],"whereNote":null,"sources":[{"title":"Bookbinding","url":"https://en.wikipedia.org/wiki/Bookbinding"},{"title":"Book","url":"https://en.wikipedia.org/wiki/Book"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"borax","name":"Borax","kind":"raw","category":"ground","title":"How borax is mined","url":"https://assemblyline.org/make/borax","stations":5,"upstream":0,"downstream":0,"depth":0,"dek":"California's great borate pit is 230 meters deep, and its ore gets dissolved completely so clean crystals can regrow.","answer":"Borax comes out of a dead lake. In California's Mojave Desert, crews drill and blast a huge pit in the Kramer deposit and truck the ore to crushers. The plant then dissolves the borates in hot liquor, lets clay settle, and cools the liquid until clean crystals grow. Those are filtered, dried and shipped as borax pentahydrate, borax decahydrate or boric acid.","aka":["tincal","sodium borate"],"inputs":[],"uses":[],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":[],"steps":[{"name":"Blast the old lakebed","process":"mine","text":"Drills bore holes for explosives that loosen both the overburden and the ore. Large shovels scoop the broken rock into 220-ton haul trucks. The Boron pit measures 3.2 km long and up to 230 m deep.","inputs":[]},{"name":"Crush to one inch","process":"crush","text":"Surface crushers break the trucked rock to about one inch, and a conveyor carries it to the processing plant.","inputs":[]},{"name":"Dissolve in hot liquor","process":"wash","text":"Crushed ore meets hot liquor and the borates go into solution. Screens catch the insoluble rock and sand that refuse to dissolve.","inputs":[]},{"name":"Settle out the clay","process":"separate","text":"Saturated solution flows into thickener tanks, where heavy clay sinks to the bottom and clear liquor passes on.","inputs":[]},{"name":"Grow and dry crystals","process":"dry","text":"Crystallizers cool the liquor until borate crystals form. The slurry is poured over fabric filters to shed water, and rotating dryers finish the damp crystals before they ride a belt to storage and shipping.","inputs":[]}],"facts":["Borax was first found in dry lake beds in Tibet, and native tincal was traded along the Silk Road to Arabia by the 8th century AD.","Melted borax dissolves many metal oxides, and the result is a glass.","The lake behind California's Boron deposit existed about 16 million years ago, fed by hot springs carrying sodium and boron."],"where":[],"whereNote":null,"sources":[{"title":"Borax Open-Pit Mine, Boron, California","url":"https://www.nsenergybusiness.com/projects/borax-open-pit-mine-boron-california"},{"title":"Rio Tinto Borax Mine (NASA)","url":"https://eol.jsc.nasa.gov/Collections/EarthObservatory/articles/RioTintoBoraxMine.htm"},{"title":"Borax","url":"https://en.wikipedia.org/wiki/Borax"},{"title":"Evaporite","url":"https://en.wikipedia.org/wiki/Evaporite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bottled-water","name":"Bottled water","kind":"product","category":"drink","title":"How bottled water is made","url":"https://assemblyline.org/make/bottled-water","stations":6,"upstream":18,"downstream":0,"depth":6,"dek":"Bottlers disinfect water with ozone gas in place of chlorine, because chlorine would leave a taste and smell.","answer":"Bottled water starts as spring, well or municipal water. Depending on the label it is filtered, purified by reverse osmosis or distillation, and disinfected with ozone gas. Bottles are blown from PET plastic, filled and capped. On average a bottler uses 1.32 liters of water for each liter sold, counting treatment, bottling and plant upkeep.","aka":["mineral water","spring water","purified water"],"inputs":["water","pet-plastic"],"uses":[],"grounds":["water","natural-gas","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["water","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","oxygen","carbon-dioxide","crude-oil","hydrogen","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Draw the source water","process":"drill","text":"Spring water flows naturally from an underground formation to the surface. Mineral water is groundwater that has flowed over rock and emerged from the ground, and other bottled water starts as well or municipal supply.","inputs":["water"]},{"name":"Filter out the particles","process":"separate","text":"Water flows through filters that hold back particles, and absolute 1 micron filtration is fine enough to remove the parasite Cryptosporidium. Mineral water is allowed only a limited cleanup in the EU, such as removing unstable iron and sulfur compounds.","inputs":[]},{"name":"Purify through a membrane","process":"separate","text":"Water sold as purified is made by distillation, deionization or reverse osmosis. Reverse osmosis pushes water under pressure through a membrane that holds back dissolved minerals.","inputs":[]},{"name":"Disinfect with ozone","process":"react","text":"Bottlers of all types of water typically dissolve ozone gas into it to kill microbes. It has played this role in the industry since the 1970s, and it leaves none of the taste and odor that chlorine does.","inputs":[]},{"name":"Form the bottles","process":"blow","text":"PET plastic has replaced glass for most single-serving bottles, because it is light and resists breaking. Preforms are blown into bottle shape, often right at the plant.","inputs":["pet-plastic"]},{"name":"Fill and cap","process":"fill","text":"Bottles are filled with the treated water and capped. Under US rules the product cannot contain sweeteners or chemical additives to be sold as bottled water.","inputs":[]}],"facts":["PET bottles were patented in 1973 by the DuPont engineer Nathaniel Wyeth.","Federal quality standards for bottled water in the United States were first adopted in 1973, the same year as the PET bottle patent."],"where":[],"whereNote":null,"sources":[{"title":"Bottled water","url":"https://en.wikipedia.org/wiki/Bottled_water"},{"title":"Reverse osmosis","url":"https://en.wikipedia.org/wiki/Reverse_osmosis"},{"title":"Bottled Water Everywhere: Keeping it Safe (FDA)","url":"https://www.fda.gov/consumers/consumer-updates/bottled-water-everywhere-keeping-it-safe"},{"title":"A Brief History of the Role of Ozone in Water Bottling","url":"https://wcponline.com/2001/10/15/brief-history-role-ozone-water-bottling/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bourbon","name":"Bourbon","kind":"product","category":"drink","title":"How bourbon is made","url":"https://assemblyline.org/make/bourbon","stations":6,"upstream":43,"downstream":0,"depth":6,"dek":"Bourbon barrels can be used only once for bourbon, so the industry exports its leftover barrels around the world.","answer":"Bourbon is a whiskey made from a grain mix of at least 51 percent corn, fermented with yeast, distilled and aged in new charred oak containers. The clear spirit, called white dog, takes its color and vanilla flavor from the charred wood. It is diluted and bottled at no less than 40 percent alcohol.","aka":["bourbon whiskey","Kentucky bourbon"],"inputs":["corn","barley","water","yeast","wine-barrel","glass-bottle"],"uses":[],"grounds":["corn","barley","water","timber","silica-sand","limestone","sugarcane","sugar-beet","rock-salt","trona","iron-ore","air","dolomite","manganese-ore","natural-gas","coal","quartz","crude-oil","sulfur"],"upstreamSlugs":["corn","barley","water","yeast","wine-barrel","glass-bottle","molasses","timber","steel","silica-sand","soda-ash","limestone","polyethylene","sugarcane","sugar-beet","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","rock-salt","ammonia","carbon-dioxide","trona","ethylene","iron-ore","coke","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","naphtha","coal","quartz","charcoal","crude-oil","sulfur","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Grind and mix the mash","process":"mix","text":"The grain, at least 51 percent corn with the rest any cereal grain, is ground and mixed with water. Mash from a previous distillation is often added to make a sour mash and keep batches consistent.","inputs":["corn","barley","water"]},{"name":"Ferment with yeast","process":"ferment","text":"Yeast is added and the mash ferments. The sour mash also controls the growth of bacteria that could taint the whiskey.","inputs":["yeast"]},{"name":"Distill twice","process":"refine","text":"Most modern bourbon is first run through a column still, then redistilled in a doubler, which is basically a pot still. The spirit comes off at typically between 65 and 80 percent alcohol.","inputs":[]},{"name":"Fill charred barrels","process":"fill","text":"The clear white dog is put into new charred oak containers, almost always American white oak barrels, at no more than 62.5 percent alcohol.","inputs":["wine-barrel"]},{"name":"Age in the wood","process":"dry","text":"Caramelized sugars and vanillins in the charred wood give the spirit color and much of its flavor. Straight bourbon must age at least two years, and the longer it stays the more color it gains.","inputs":[],"spec":"at least 2 years for straight bourbon"},{"name":"Filter, dilute, bottle","process":"fill","text":"After maturing, the whiskey is typically filtered, diluted with water and bottled at no less than 80 US proof, which is 40 percent alcohol.","inputs":["glass-bottle","water"]}],"facts":["Congress recognized bourbon in 1964 as a distinctive product of the United States.","Barrels cannot be reused for bourbon, so most are sold to distillers in Canada, Scotland, Ireland, Mexico and the Caribbean.","Emptied barrels remain saturated with 2 to 3 U.S. gallons of bourbon."],"where":[],"whereNote":null,"sources":[{"title":"Bourbon whiskey","url":"https://en.wikipedia.org/wiki/Bourbon_whiskey"},{"title":"Whisky","url":"https://en.wikipedia.org/wiki/Whisky"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bowling-ball","name":"Bowling ball","kind":"product","category":"play","title":"How bowling balls are made","url":"https://assemblyline.org/make/bowling-ball","stations":8,"upstream":69,"downstream":0,"depth":10,"dek":"Bowling balls are poured three times: once for the core, once to round it out, and once for the colored shell.","answer":"A bowling ball is a cast sandwich. A heavy core is poured from resin in a mold, surrounded with filler to make it round, then dropped into a second mold where liquid urethane is poured around it. The shell sets in about two minutes. The ball is then cut down, polished, engraved, and later drilled for a bowler's hand.","aka":["tenpin ball","ten-pin bowling ball"],"inputs":["plastic","glass","polyurethane","paint"],"uses":[],"grounds":["natural-gas","silica-sand","limestone","water","crude-oil","rock-salt","trona","air","titanium-ore","iron-ore","sulfur","corn","coal","tin-ore","sugarcane","soybeans","rapeseed","clay","sugar-beet","dolomite","manganese-ore","quartz","timber"],"upstreamSlugs":["plastic","glass","polyurethane","paint","naphtha","natural-gas","ethylene","propylene","silica-sand","soda-ash","limestone","nitric-acid","chlorine","water","titanium-dioxide","pigment","acrylic","tin-can","crude-oil","hydrogen","rock-salt","ammonia","carbon-dioxide","lime","trona","air","sulfuric-acid","titanium-ore","coke","oxygen","iron-ore","carbon-black","sulfur","methanol","tinplate","lacquer","ink","corn","yeast","coal","steel","tin","ethanol","vegetable-oil","phenolic-resin","molasses","pig-iron","magnesium","steel-scrap","manganese","argon","tin-ore","sugarcane","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","sugar-beet","dolomite","silicon","propane","manganese-ore","benzene","quartz","charcoal","timber","toluene"],"downstreamSlugs":[],"steps":[{"name":"Batch the resin for cores","process":"mix","text":"Raw materials are mixed in a sealed area to keep fumes away from workers. The result is a liquid resin that Storm's production chief compared to making a cake, with lighter or heavier ingredients chosen to set the weight.","inputs":["plastic"]},{"name":"Pour the core","process":"cast","text":"The resin, at roughly 260 degrees, is poured into molds in many shapes. Each shape makes the ball roll differently, much as the head of a golf iron does. After about six minutes of cooling the core pops out.","inputs":[],"spec":"about 260 degrees"},{"name":"Fill out to a sphere","process":"cast","text":"The core is centered in a mold and surrounded with a mix of glass microbubbles and a denser filler. Different proportions change the ball's weight while it keeps the same 27-inch circumference.","inputs":["glass"]},{"name":"Pour the urethane shell","process":"cast","text":"The round core goes into another mold, and liquid urethane is poured around it. A ball can carry up to three colors, and the swirl is unique because of how the mix fills the mold. Mixing generates heat, and the shell hardens in about two minutes.","inputs":["polyurethane"]},{"name":"Crack the mold and cool","process":"dry","text":"The mold is cracked off like an egg and the balls cool on a rack overnight. A hole left by the pin that held the core is plugged, often with a color that tells workers which core is inside.","inputs":[]},{"name":"Cut, sand and polish","process":"grind","text":"A machine cuts the shell down to size. The ball is then sanded for a matte finish or polished for a shine, and each finish rolls differently on oily lanes.","inputs":[]},{"name":"Engrave the logo","process":"print","text":"A machine rotates the ball while it engraves up to five points. Workers fill the engraved lines with paint so the logo stands out.","inputs":["paint"]},{"name":"Drill the finger holes","process":"machine","text":"Holes for two fingers and the thumb are drilled to fit the bowler's hand. This is usually done in a pro shop, not the factory, and the rules limit how much material can be taken out.","inputs":[]}],"facts":["One Utah factory can pour as many as 3,000 premium bowling balls in a day, and a ball takes about three days from start to finish.","A patented scented ball can be made in over 11,000 different fragrances, from bacon to baked goods.","Bowling balls were made of hardwood until rubber ones appeared in 1905, and plastic ones in 1959."],"where":[],"whereNote":null,"sources":[{"title":"How are bowling balls made? Utah factory gives inside look","url":"https://www.ksl.com/article/39463986"},{"title":"How A Bowling Ball is Made","url":"https://bowl.com/welcome/how-a-bowling-ball-is-made"},{"title":"Bowling ball","url":"https://en.wikipedia.org/wiki/Bowling_ball"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"brake-pad","name":"Brake pad","kind":"product","category":"machines","title":"How brake pads are made","url":"https://assemblyline.org/make/brake-pad","stations":7,"upstream":76,"downstream":0,"depth":10,"dek":"A brake pad's steel plate gets a texture pressed into its back so the friction block has something to grip.","answer":"Steel coil is punched into backing plates, textured and sprayed with adhesive. Weighed friction ingredients are mixed and pressed into a mold, then heat bonds the block to the plate. The pads cure in an oven, are ground to final height and grooved down the middle, and a coating goes on last.","aka":["disc brake pad","brake lining"],"inputs":["sheet-steel","adhesive","phenol","copper","phenolic-resin","kevlar","paint"],"uses":[],"grounds":["water","air","copper-ore","zinc-ore","crude-oil","sulfur","natural-gas","rock-salt","titanium-ore","iron-ore","limestone","dolomite","manganese-ore","coal","quartz","timber","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["sheet-steel","adhesive","phenol","copper","phenolic-resin","kevlar","paint","steel","zinc","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","benzene","propylene","air","copper-ore","oxygen","sulfuric-acid","formaldehyde","p-xylene","ammonia","chlorine","titanium-dioxide","pigment","tin-can","pig-iron","magnesium","steel-scrap","lime","manganese","argon","zinc-ore","ethylene","methanol","acetone","caustic-soda","nitric-acid","crude-oil","hydrogen","naphtha","toluene","sulfur","natural-gas","rock-salt","titanium-ore","coke","iron-ore","carbon-black","tinplate","lacquer","ink","limestone","dolomite","silicon","propane","manganese-ore","coal","tin","ethanol","vegetable-oil","quartz","charcoal","timber","tin-ore","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Stamp the backing plate","process":"stamp","text":"A punch press cuts plates from a large coil of steel. Each one will carry the friction material and fit into the brake caliper.","inputs":["sheet-steel"]},{"name":"Texture and glue the plate","process":"press","text":"A die presses a texture into the back of the plate, and a quick coat of adhesive is sprayed over it. Both help the friction material hold on.","inputs":["adhesive"]},{"name":"Mix the friction blend","process":"mix","text":"Fibers, metal particles, fillers and a binding resin are weighed out and blended. The ratios decide how the pad resists heat and how long it lasts.","inputs":["phenol","copper","phenolic-resin","kevlar"]},{"name":"Hot-press onto the plate","process":"press","text":"The mix is pressed into a mold matching the vehicle's pad shape. A machine then joins it to the plate with heat, melting the resin into a bond.","inputs":[]},{"name":"Bake it hard","process":"dry","text":"The pads leave the mold and travel through an oven until the binder has cured throughout.","inputs":[]},{"name":"Grind and groove","process":"grind","text":"Wheels grind the friction face to final height, and a groove is cut down the middle.","inputs":[]},{"name":"Coat and label","process":"coat","text":"A colored coating goes on, the pads are baked and cooled again, and a final braking layer helps them bed in against the rotor.","inputs":["paint"]}],"facts":["Disc brakes use two pads per rotor, held and pressed by a caliper.","Ingredient ratios are what give each pad recipe its heat resistance and durability."],"where":[],"whereNote":null,"sources":[{"title":"Brake pad","url":"https://en.wikipedia.org/wiki/Brake_pad"},{"title":"Stamping (metalworking)","url":"https://en.wikipedia.org/wiki/Stamping_(metalworking)"},{"title":"How Quality Brakes Are Made","url":"https://powernationtv.com/post/how-quality-brakes-are-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"brass","name":"Brass","kind":"material","category":"metals","title":"How brass is made","url":"https://assemblyline.org/make/brass","stations":6,"upstream":24,"downstream":35,"depth":4,"dek":"Brass is copper with zinc stirred in, and it is soft enough to cast, extrude or machine into almost anything.","answer":"Brass is an alloy of copper and zinc, generally about two parts copper to one part zinc. Foundries melt copper, add zinc and sometimes small amounts of lead, tin or aluminum, then cast billets. The billets are extruded or rolled into rod, tube and sheet, and often machined into fittings. Nearly 90 percent of brass is recycled.","aka":["copper-zinc alloy","yellow metal"],"inputs":["copper","zinc","lead","tin","aluminum"],"uses":["aa-battery","wristwatch","faucet","padlock","tire","electric-guitar","trumpet","ballpoint-pen","pencil-eraser","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","light-switch","power-outlet","leather-belt","handbag","flag","phone-charger","usb-cable","zipper"],"grounds":["copper-ore","water","air","zinc-ore","lead-ore","tin-ore","crude-oil","coal","sulfur","bauxite","rock-salt","limestone"],"upstreamSlugs":["copper","zinc","lead","tin","aluminum","copper-ore","water","oxygen","air","sulfuric-acid","zinc-ore","lead-ore","coke","tin-ore","crude-oil","coal","petroleum-coke","alumina","sulfur","bauxite","caustic-soda","lime","rock-salt","limestone"],"downstreamSlugs":["aa-battery","wristwatch","faucet","padlock","tire","electric-guitar","trumpet","ballpoint-pen","pencil-eraser","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","light-switch","power-outlet","leather-belt","handbag","flag","phone-charger","usb-cable","zipper","car","electric-car","bicycle","motorcycle","down-jacket","raincoat","backpack","suitcase","jeans"],"steps":[{"name":"Melt the copper","process":"melt","text":"Refined copper is melted in a furnace. Brass melts at a low temperature for a metal alloy, between 900 and 940 °C depending on composition, so it flows easily into molds.","inputs":["copper"],"spec":"900 to 940 °C"},{"name":"Stir in the zinc","process":"mix","text":"Zinc goes into the bath in a proportion set by the grade. More zinc makes brass harder and paler, and more copper makes it redder and softer. Brass with 15 percent or less zinc stands up well to zinc loss.","inputs":["zinc"]},{"name":"Tune with minor metals","process":"mix","text":"Small additions change what the brass does. About 2 percent lead makes it cut cleanly on a lathe. Tin helps it survive seawater, and aluminum makes it stronger and more corrosion resistant.","inputs":["lead","tin","aluminum"]},{"name":"Cast billets","process":"cast","text":"The melt is cast into logs called billets, ready to be heated and pushed or rolled into shape. Brass is easy to cast because of its low melting point and flow characteristics.","inputs":[]},{"name":"Extrude into rod and tube","process":"extrude","text":"A press pushes hot billet through a shaped die and out comes a continuous length of rod, tube or profile. Brass is more malleable than bronze or zinc, so it forms readily.","inputs":[]},{"name":"Machine the fittings","process":"machine","text":"Brass bar is turned and milled on machines into locks, valves, hinges, plumbing fittings and zippers. Its softness and low friction are the reasons it is used.","inputs":[]}],"facts":["Salt water slowly leaches the zinc from ordinary brass and leaves porous copper behind, so ships use marine brass with about 1 percent tin.","Brass is often used in tools and fittings that must be non-sparking, near flammable or explosive materials.","Brass is the usual metal for instruments built from long, narrow tubing, because it is malleable and easy to work."],"where":[],"whereNote":null,"sources":[{"title":"Brass","url":"https://en.wikipedia.org/wiki/Brass"},{"title":"Zinc","url":"https://en.wikipedia.org/wiki/Zinc"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bread","name":"Bread","kind":"product","category":"food","title":"How bread is made","url":"https://assemblyline.org/make/bread","stations":7,"upstream":28,"downstream":1,"depth":9,"dek":"The Chorleywood process of 1961 swapped long rising for intense mechanical mixing.","answer":"Flour, water, yeast and salt are mixed until gluten forms a stretchy network. The dough is divided, shaped, proofed so yeast gas inflates it, and baked in a tunnel oven. In the Chorleywood process, intense mechanical mixing cuts the fermentation time. The crust browns through the Maillard reaction.","aka":["loaf","sliced bread","white bread","sandwich bread"],"inputs":["flour","water","yeast","table-salt"],"uses":["fish-sticks"],"grounds":["water","wheat","rock-salt","seawater","air","sugarcane","sugar-beet","corn","natural-gas","limestone","crude-oil"],"upstreamSlugs":["flour","water","yeast","table-salt","wheat","vitamin-c","molasses","rock-salt","seawater","corn-starch","hydrogen","air","sugar","plastic-bottle","sugarcane","sugar-beet","corn","natural-gas","lime","pet-plastic","limestone","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","crude-oil"],"downstreamSlugs":["fish-sticks"],"steps":[{"name":"Weigh the ingredients","process":"mix","text":"Silos feed flour into a scale and water is metered in. Salt, yeast, fat and additives go in by weight, since weighing is more accurate than measuring by volume.","inputs":["flour","water","yeast","table-salt"]},{"name":"Mix and develop the gluten","process":"knead","text":"Large mixers beat the dough until the gluten proteins link into a stretchy network that can trap gas. The Chorleywood process, developed in 1961, uses intense mechanical working to dramatically cut the fermentation period and the time to make a loaf.","inputs":[]},{"name":"Divide and round","process":"cut","text":"A divider chops the dough into pieces of equal weight, one for each loaf. Rounders roll each piece into a ball and let it rest.","inputs":[]},{"name":"Mold the loaf","process":"mold","text":"Each rested piece is sheeted flat, rolled up and dropped into a baking tin. The tin holds the loaf's shape as it rises.","inputs":[]},{"name":"Proof in a warm cabinet","process":"ferment","text":"Tins ride through a warm, humid cabinet while yeast feeds on sugars and gives off carbon dioxide. Gas bubbles swell the dough until it is about as tall as the finished loaf.","inputs":[]},{"name":"Bake in a tunnel oven","process":"bake","text":"The tins travel slowly through a long oven. The heat sets the crumb, drives off water and browns the crust, which gets its flavor from the Maillard reaction between sugars and amino acids at the hot surface.","inputs":[]},{"name":"Cool, slice and bag","process":"package","text":"Loaves are removed from the tins and cooled until the center is firm enough to slice. Blades cut the loaf, and a machine bags and seals it.","inputs":[]}],"facts":["Starch residue on pounding stones from about 30,000 years ago hints that people were making bread-like foods that long ago.","An early leavened bread was baked as early as 6000 BC in southern Mesopotamia.","Bakers write recipes as percentages of the flour weight, with flour fixed at 100%."],"where":[],"whereNote":null,"sources":[{"title":"Bread","url":"https://en.wikipedia.org/wiki/Bread"},{"title":"Baker's yeast","url":"https://en.wikipedia.org/wiki/Baker%27s_yeast"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"brick","name":"Brick","kind":"product","category":"minerals","title":"How bricks are made","url":"https://assemblyline.org/make/brick","stations":7,"upstream":2,"downstream":0,"depth":1,"dek":"A brick's color records its recipe: iron turns it pink or red, and lime turns it pale yellow or white.","answer":"Clay bricks are made from clay and shale ground to a paste with water, squeezed through a die as a long slab, and cut into bricks by a wall of wires. The raw bricks ride through a tunnel kiln on conveyors or kiln cars, where firing makes them hard and durable.","aka":["clay brick","fired brick","house brick"],"inputs":["clay","water"],"uses":[],"grounds":["clay","water"],"upstreamSlugs":["clay","water"],"downstreamSlugs":[],"steps":[{"name":"Dig the clay and shale","process":"mine","text":"Clay and shale are the raw ingredients. They are the product of thousands of years of erosion of rocks such as granite, and they are chemically stable. Silica makes up 50% to 60% of the mix by weight and alumina 20% to 30%.","inputs":["clay"]},{"name":"Grind it with water","process":"crush","text":"The clay is ground and blended with water in a pugmill. For extruded bricks the mix is 10–15% water if stiff, or 20–25% if soft.","inputs":["water"],"spec":"10–15% water for stiff extrusion"},{"name":"Squeeze out a column","process":"extrude","text":"The mix is forced through a steel die to make a long cable of clay with the width and depth of a brick. Most structural bricks are made this way because it produces hard, dense bricks.","inputs":[]},{"name":"Slice with wires","process":"cut","text":"A wall of tensioned wires cuts the column into brick lengths. The wires can leave faint drag marks, which is how you can recognize a wire-cut brick.","inputs":[]},{"name":"Dry the green bricks","process":"dry","inputs":[],"text":"Cut bricks still carry the water they were mixed with. They are dried before firing so that water does not flash to steam and crack them inside the kiln."},{"name":"Fire in a tunnel kiln","process":"fire","text":"Bricks ride slowly through the kiln on conveyors, rails or kiln cars, so every one sees the same heat. Soft-mud bricks are fired at 900–1,000 °C. The finished color depends on the clay chemistry, the temperature and the kiln atmosphere.","inputs":[],"spec":"900–1,000 °C for molded bricks"},{"name":"Test the strength","process":"inspect","text":"Samples are crushed to check compressive strength. In the United States, brick strength ranges from about 7 to 103 MPa depending on use, while a common English house brick shows 20–40 MPa.","inputs":[]}],"facts":["The oldest known bricks, made of shaped mud, date to before 7500 BC and were found at Tell Aswad.","The floors of the three pits of the Terracotta Army were paved with an estimated 230,000 bricks.","At the end of the 19th century, 130 brickyards along the Hudson River produced about 1 billion bricks a year at their peak."],"where":[],"whereNote":null,"sources":[{"title":"Brick","url":"https://en.wikipedia.org/wiki/Brick"},{"title":"Ceramic","url":"https://en.wikipedia.org/wiki/Ceramic"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bronze","name":"Bronze","kind":"material","category":"metals","title":"How bronze is made","url":"https://assemblyline.org/make/bronze","stations":5,"upstream":11,"downstream":3,"depth":3,"dek":"Bronze is copper hardened with about one-eighth tin, and the tin had to be traded between regions.","answer":"Bronze is copper alloyed with tin, typically about 88 percent copper and 12 percent tin. The copper is melted, the tin stirred in, and the molten alloy poured into a mold to make statues, bells, bearings or coins. Softer, lower-tin ingots can also be hammered into sheet.","aka":["tin bronze","bell metal","gunmetal"],"inputs":["copper","tin"],"uses":["drum-kit","guitar-string","bronze-statue"],"grounds":["copper-ore","water","air","tin-ore","sulfur","coal"],"upstreamSlugs":["copper","tin","copper-ore","water","oxygen","air","sulfuric-acid","tin-ore","coke","sulfur","coal"],"downstreamSlugs":["drum-kit","guitar-string","bronze-statue"],"steps":[{"name":"Melt the copper","process":"melt","text":"The copper goes into the crucible first. Copper-based alloys melt at lower temperatures than steel or iron, at about 950 °C for bronze, so a foundry can make them without a blast furnace.","inputs":["copper"]},{"name":"Stir in the tin","process":"mix","text":"Tin is added to the melt, usually around 10 to 12 percent. It is much rarer than copper, and the two are seldom found together, so serious bronze work has always meant trade between regions.","inputs":["tin"]},{"name":"Pour into a mold","process":"cast","text":"The molten bronze is poured into a mold. Tin bronze beat the earlier arsenic copper because its mix could be controlled more easily, and the result was stronger and easier to cast.","inputs":[]},{"name":"Hammer or roll sheet","process":"forge","text":"For sheet, a softer bronze with only about 6 percent tin is cast into ingots and hammered flat. Bronze Age helmets and armor were made this way, while blades were cast from the harder bronze with about 10 percent tin.","inputs":[]},{"name":"Machine to size","process":"machine","text":"Bronze parts are finished by turning and grinding. They are tough and have low friction against other metals, which is why they are used for bearings, bushings, springs and electrical connectors.","inputs":[]}],"facts":["The earliest known tin-copper artifact dates to about 4650 BCE, from a site at Pločnik in Serbia.","The Bronze Age gave way to the Iron Age after population migrations around 1200 to 1100 BCE disrupted the tin trade.","Bronze corrodes only on the surface, because a layer of copper oxide forms and then protects the metal underneath."],"where":[],"whereNote":null,"sources":[{"title":"Bronze","url":"https://en.wikipedia.org/wiki/Bronze"},{"title":"Tin","url":"https://en.wikipedia.org/wiki/Tin"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bell","name":"Bronze bell","kind":"product","category":"hardware","title":"How bronze bells are made","url":"https://assemblyline.org/make/bell","stations":6,"upstream":13,"downstream":0,"depth":3,"dek":"A bell's sound comes from its shape, so it is cast mouth-down in a pit and then shaved to tune.","answer":"A bell is cast from bronze with a high tin content, often about 80 percent copper and 20 percent tin. The founder builds a clay core and an outer mold with a gap between them, lowers the case over the core, buries it in a pit and pours metal into the gap. The cooled bell is tuned.","aka":["church bell","cast bell"],"inputs":["clay","silica-sand","copper","tin"],"uses":[],"grounds":["clay","silica-sand","copper-ore","water","air","tin-ore","sulfur","coal"],"upstreamSlugs":["clay","silica-sand","copper","tin","copper-ore","water","oxygen","air","sulfuric-acid","tin-ore","coke","sulfur","coal"],"downstreamSlugs":[],"steps":[{"name":"Build the core","process":"mold","text":"A core is built up from brick or coke on a base plate, then covered with loam, a clay mix with straw. It is shaped to the inside profile of the finished bell and dried with gentle heat.","inputs":["clay"]},{"name":"Make the outer mold","process":"mold","text":"Loam, a mix of clay, sand and straw, is packed inside a perforated iron case and shaped to the outside profile, then dried and smoothed. Graphite and whiting give the surface a final smooth coat.","inputs":["clay","silica-sand"]},{"name":"Close and bury the mold","process":"assemble","text":"The case is inverted and lowered over the core, leaving a hollow in the shape of the bell, and clamped down. It is often buried in a pit to hold the weight of the metal and let it cool evenly.","inputs":[]},{"name":"Melt the bell metal","process":"melt","text":"Copper and tin are melted together in a furnace to make bell metal, a hard bronze that rings clearly.","inputs":["copper","tin"]},{"name":"Pour it mouth-down","process":"cast","text":"The molten bronze is poured into the gap between core and case. After it cools slowly, the mold is dug up and broken away.","inputs":[]},{"name":"Tune on the lathe","process":"machine","text":"Tiny amounts of metal are shaved from the inside of the bell until its harmonics ring in tune with each other.","inputs":[]}],"facts":["The traditional metal for bells is a bronze of about 23% tin, known as bell metal.","The St. Petersglocke at Cologne Cathedral weighs 24 tons and was cast in 1922.","Bellfounding in Europe dates to the 4th or 5th century."],"where":[],"whereNote":null,"sources":[{"title":"Bell","url":"https://en.wikipedia.org/wiki/Bell"},{"title":"Bronze","url":"https://en.wikipedia.org/wiki/Bronze"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bronze-statue","name":"Bronze statue","kind":"product","category":"hardware","title":"How bronze statues are made","url":"https://assemblyline.org/make/bronze-statue","stations":7,"upstream":16,"downstream":0,"depth":4,"dek":"Bronze swells slightly just before it sets, so it fills the finest details of the mold.","answer":"Most bronze statues are made by lost-wax casting. An artist makes a model, then a mold of it produces a wax twin. The wax is coated in ceramic shell and melted out, leaving a hollow. Bronze is poured in, the shell is chipped away, and the surface is welded, polished and patinated.","aka":["cast bronze sculpture","lost-wax statue"],"inputs":["clay","beeswax","silica-sand","bronze"],"uses":[],"grounds":["clay","silica-sand","honeycomb","copper-ore","water","air","tin-ore","sulfur","coal"],"upstreamSlugs":["clay","beeswax","silica-sand","bronze","honeycomb","copper","tin","copper-ore","water","oxygen","air","sulfuric-acid","tin-ore","coke","sulfur","coal"],"downstreamSlugs":[],"steps":[{"name":"Sculpt the model","process":"mold","text":"The artist builds the figure in clay or plaster on a supporting armature, working through smaller study models for large works.","inputs":["clay"]},{"name":"Make the wax copy","process":"cast","text":"A mold is taken from the model and a wax copy is cast in it. For large sculptures the wax is hollow, with a core inside, and wax sprues are added to carry the metal in.","inputs":["beeswax"]},{"name":"Coat it in ceramic","process":"coat","text":"Workers dip the wax tree repeatedly in a ceramic slurry and sand until a hard shell covers it.","inputs":["silica-sand"]},{"name":"Burn out the wax","process":"fire","text":"The shell is heated so the wax melts and drains away. The hollow left behind is an exact negative of the figure.","inputs":[]},{"name":"Pour the bronze","process":"cast","text":"Molten bronze is poured through the sprues and fills the hollow from the bottom up so that it does not splash. Bronze alloys expand slightly just before setting and shrink after.","inputs":["bronze"]},{"name":"Chip, weld and chase","process":"machine","text":"Once cool, the shell is chipped away and the sprues are cut off with a saw. Gas holes are welded, and tool marks are polished out.","inputs":[]},{"name":"Patinate the surface","process":"coat","text":"Corrosive chemicals are applied, which give the artist control over the color and finish.","inputs":[]}],"facts":["Investment casting has been used in various forms for the last 5,000 years.","During the Shang dynasty, ritual bronzes were buried in sets of up to 200 pieces in royal tombs.","From the ninth through the thirteenth century, the Chola dynasty in South India represented the pinnacle of bronze casting."],"where":[],"whereNote":null,"sources":[{"title":"Bronze sculpture","url":"https://en.wikipedia.org/wiki/Bronze_sculpture"},{"title":"Investment casting","url":"https://en.wikipedia.org/wiki/Investment_casting"},{"title":"Lost-wax casting","url":"https://en.wikipedia.org/wiki/Lost-wax_casting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"brown-sugar","name":"Brown sugar","kind":"product","category":"food","title":"How brown sugar is made","url":"https://assemblyline.org/make/brown-sugar","stations":6,"upstream":7,"downstream":0,"depth":3,"dek":"Refineries reach brown sugar two ways: boil it from dark syrups, or coat white crystals with brown syrup.","answer":"A sugar refinery has two roads to brown sugar. It can boil the darker syrups left over from white sugar in a vacuum pan until brown crystals form, or it can coat finished white crystals with a brown syrup. Light grades carry less molasses than dark ones. Either way, a film of syrup keeps the sugar damp and soft.","aka":["light brown sugar","dark brown sugar","soft brown sugar"],"inputs":["sugar","molasses"],"uses":[],"grounds":["sugarcane","sugar-beet","water","limestone"],"upstreamSlugs":["sugar","molasses","sugarcane","sugar-beet","water","lime","limestone"],"downstreamSlugs":[],"steps":[{"name":"Wash the raw crystals","process":"wash","text":"Raw cane sugar is mingled with a warm, heavy syrup that loosens its molasses coat. A spinning basket flings the syrup off, and the crystals go on to become white sugar. The syrup is saved.","inputs":["sugar"]},{"name":"Boil the leftover syrup","process":"cook","text":"One patent traces that syrup through char filters into a vacuum pan, where it boils and partly crystallizes. A centrifuge takes out those crystals, and the darker syrup moves to a pan of its own.","inputs":[]},{"name":"Crystallize from dark syrups","process":"cook","text":"In the brown pan the syrup boils and crystallizes again into a thick mass of crystals in liquid, called massecuite. Britannica describes a blend of brown and yellow syrups, plus caramel for the darkest shades.","inputs":[]},{"name":"Spin off extra syrup","process":"separate","text":"The massecuite drops into a centrifugal basket. It spins for a set time to strip syrup from the crystals, then the basket slows, reverses, and a plow scrapes the damp sugar off the wall.","inputs":[]},{"name":"Or coat white crystals","process":"mix","text":"The other road starts from refined white crystals and adds a brown-sugar syrup. Light brown sugar gets about 3.5 percent molasses and dark brown about 6.5 percent.","inputs":["molasses"]},{"name":"Dry and bag","process":"package","text":"Refinery products are dried and sent to food-grade packing plants. Packages run from single servings to one-ton bags.","inputs":[]}],"facts":["Late in the 19th century, white sugar refiners ran a smear campaign against brown sugar, showing magnified photos of microbes living in it.","Brown sugars are graded by darkness, and regular commercial brown sugar holds up to 10% molasses by weight."],"where":[],"whereNote":null,"sources":[{"title":"Sugar: crystallization and refining, Britannica","url":"https://www.britannica.com/topic/sugar-chemical-compound/Crystallization"},{"title":"US3074821A, Method for making soft or brown sugar","url":"https://patents.google.com/patent/US3074821/en"},{"title":"Brown sugar","url":"https://en.wikipedia.org/wiki/Brown_sugar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"bubble-wrap","name":"Bubble wrap","kind":"product","category":"plastics","title":"How bubble wrap is made","url":"https://assemblyline.org/make/bubble-wrap","stations":5,"upstream":7,"downstream":0,"depth":5,"dek":"Bubble wrap began as a failed plastic wallpaper.","answer":"Polyethylene beads are melted and squeezed into two thin films, with a barrier layer built in to hold air. One film is sucked into a drum full of tiny holes so it puffs into bubbles, and the second film is bonded flat across the back. The seal traps a pocket of air in every bubble.","aka":["bubble pack","air cushion wrap"],"inputs":["polyethylene"],"uses":[],"grounds":["natural-gas","water","crude-oil"],"upstreamSlugs":["polyethylene","ethylene","naphtha","natural-gas","water","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Melt the resin beads","process":"melt","text":"Polyethylene beads about the size of pea gravel drop into an extruder, a long heated barrel with a screw inside. Heater bands and the friction of the screw turn the beads into a liquid.","inputs":["polyethylene"],"spec":"barrel at about 180 degrees"},{"name":"Squeeze out two films","process":"extrude","text":"The melt is pushed out of the machine as two stacked sheets of clear film. Plain polyethylene lets air creep out, so a barrier that holds air is sealed inside the plastic as it is extruded. Early makers coated the finished film with Saran instead.","inputs":[]},{"name":"Suck one film into a drum","process":"mold","text":"One film wraps around a drum punched with holes. Suction through the holes pulls the soft plastic down into each one, and every dimple becomes a bubble.","inputs":[]},{"name":"Seal the flat film on","process":"laminate","text":"The second film is pressed over the first. Where the two stick together, air is trapped in each dimple.","inputs":[]},{"name":"Wind it on rolls","process":"package","text":"The finished sheet is wound into rolls. Small bubbles suit light items, and larger bubbles absorb more shock for heavier ones.","inputs":[]}],"facts":["Alfred Fielding and Marc Chavannes made it in 1957 while trying to create a three-dimensional plastic wallpaper.","One of the first big uses came in 1960, when IBM 1401 computers were shipped in it.","The most common bubble size is about 1 centimeter across."],"where":[],"whereNote":null,"sources":[{"title":"Bubble wrap","url":"https://en.wikipedia.org/wiki/Bubble_wrap"},{"title":"Bubble Wrap Manufacturing Process: How is Bubble Wrap Made?","url":"https://www.stanleypackaging.com.au/blog/bubble-wrap-manufacturing-process-how-is-bubble-wrap-made/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"butter","name":"Butter","kind":"product","category":"food","title":"How butter is made","url":"https://assemblyline.org/make/butter","stations":7,"upstream":5,"downstream":3,"depth":2,"dek":"Butter is cream that has been abused until the fat globules break their skins and clump together.","answer":"A separator spins fresh milk into cream, which is pasteurized and cooled. Churning beats the cream until the membranes around the fat globules rupture and the fat clumps into grains. The buttermilk is drained, the grains are worked into a smooth mass, salted if wanted, and packed. Commercial butter is about 80% butterfat.","aka":["sweet cream butter","cultured butter","salted butter"],"inputs":["raw-milk","cream","table-salt"],"uses":["croissant","caramel","toffee"],"grounds":["raw-milk","rock-salt","seawater"],"upstreamSlugs":["raw-milk","cream","table-salt","rock-salt","seawater"],"downstreamSlugs":["croissant","caramel","toffee"],"steps":[{"name":"Spin cream off the milk","process":"separate","text":"A centrifugal separator whirls the milk so the lighter fat rises to the middle and runs off as cream. De Laval's separator, introduced in the late 1870s, made this a factory step.","inputs":["raw-milk"]},{"name":"Pasteurize the cream","process":"pasteurize","text":"Cream is heated to kill pathogenic bacteria, then cooled. Butter made from raw cream is very rare, and it can be dangerous.","inputs":["cream"]},{"name":"Ripen or cool it","process":"chill","text":"For cultured butter, bacteria are added and left to sour the cream. Sweet cream butter skips the culturing, and can be made in about 6 hours, compared with up to 72 hours for cultured butter.","inputs":[]},{"name":"Churn until the fat breaks out","process":"knead","text":"A large drum or continuous churn agitates the cream. Churning tears the phospholipid membranes around the fat globules, and the freed fat clumps into small grains that float in a watery liquid.","inputs":[]},{"name":"Drain the buttermilk","process":"separate","text":"The watery liquid is drained away and the grains may be rinsed with water. The liquid is the original buttermilk.","inputs":[]},{"name":"Work and salt the grains","process":"knead","text":"Rollers or paddles press the grains into one smooth mass and squeeze out extra water. Salt, added since ancient times to help butter keep, is mixed in at this point.","inputs":["table-salt"]},{"name":"Print and wrap","process":"package","text":"Butter is pressed into blocks, cut into sticks or tubs, and wrapped in foil or parchment.","inputs":[]}],"facts":["Commercial butter is about 80% butterfat and 15% water, and traditionally made butter can be as low as 65% fat.","Butter is almost pure milk fat, so it holds only traces of lactose."],"where":[],"whereNote":null,"sources":[{"title":"Butter","url":"https://en.wikipedia.org/wiki/Butter"},{"title":"Milk","url":"https://en.wikipedia.org/wiki/Milk"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"button","name":"Button","kind":"product","category":"textiles","title":"How buttons are made","url":"https://assemblyline.org/make/button","stations":8,"upstream":19,"downstream":4,"depth":7,"dek":"More than 60 percent of the world's buttons come from one town, Qiaotou in Yongjia County, China.","answer":"Liquid polyester with wax, dye and a catalyst is poured into a spinning drum, where it forms a soft sheet in about 20 minutes. The sheet is pulled out and punched into blanks. Blanks cure in water that starts at 110 °C and slowly cools, then machines cut the face and drill the holes. Drums tumble them shiny for about 24 hours.","aka":["shirt button","sew-through button","shank button"],"inputs":["polyester","water"],"uses":["dress-shirt","suit","jeans","baseball-cap"],"grounds":["water","natural-gas","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["polyester","water","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","oxygen","carbon-dioxide","crude-oil","hydrogen","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["dress-shirt","suit","jeans","baseball-cap"],"steps":[{"name":"Pour into a spinning drum","process":"cast","text":"Polyester resin, wax, dye and a catalyst go into a cylinder 4 feet across turning at about 250 rotations per minute. Centrifugal force spreads the mix into an even sheet, and more resin gives thicker buttons.","inputs":["polyester"]},{"name":"Pull out the sheet","process":"cut","text":"After about 20 minutes the resin has the texture of stale cheese, held between layers of wax that have risen and sunk to its faces. The drum stops and the sheet is cut free.","inputs":[]},{"name":"Punch the blanks","process":"stamp","text":"On a conveyor, circular steel dies descend on the still-soft sheet and punch out button-sized circles. It takes about 2 to 4 minutes per sheet.","inputs":[]},{"name":"Cure in hot water","process":"heat-treat","text":"The blanks would turn brittle if cooled in air. They sit in a tank of water heated to 110 °C, hardening as it slowly cools over 10 to 24 hours.","inputs":["water"],"spec":"10 to 24 hours"},{"name":"Cut the face","process":"machine","text":"A hopper feeds blanks into holders that clamp them against a spinning cutting tool, which forms the rim or the concave face.","inputs":[]},{"name":"Drill the holes","process":"machine","text":"The clamped pieces move beneath a set of drills that make two or four holes, and a vacuum pulls them out into a box. Hundreds can pass through in a minute.","inputs":[]},{"name":"Tumble to a shine","process":"grind","text":"Drums of water, abrasive and foaming agent spin for about 24 hours while the contents bounce themselves smooth. They are then washed and dried.","inputs":["water"],"spec":"about 24 hours"},{"name":"Check and pack","process":"inspect","text":"Finished pieces are inspected for quality and packed for garment makers.","inputs":[]}],"facts":["Buttons made from seashell were used by the Indus Valley Civilization for ornamentation by 2000 BC.","In 1918 a US government survey of the international button market listed buttons made of vegetable ivory, galalith, silk, lead, rubber and many other materials."],"where":[{"place":"Qiaotou, Yongjia County, China","share":"over 60 percent of the world's button supply"}],"whereNote":"Today, as stated by Wikipedia; no year is given.","sources":[{"title":"Online Clothing Study: How plastic buttons are made","url":"https://www.onlineclothingstudy.com/2016/08/how-plastic-buttons-are-made.html"},{"title":"Button","url":"https://en.wikipedia.org/wiki/Button"},{"title":"Sewing thread","url":"https://en.wikipedia.org/wiki/Sewing_thread"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cabbage","name":"Cabbage","kind":"raw","category":"farm","title":"How cabbage is grown","url":"https://assemblyline.org/make/cabbage","stations":5,"upstream":0,"downstream":2,"depth":0,"dek":"A cabbage head forms when the leaves cup inward. The record holder weighed 62.71 kilograms.","answer":"Seedlings usually start under cover and go out to the field while the season is young, though some seed goes directly into the ground. Leaves first spread as a rosette, then cup inward to form a dense head. Crews or machines cut the stalk below the bottom leaves, and the heads go to market, cold storage or a sauerkraut plant.","aka":["head cabbage","green cabbage","Brassica oleracea"],"inputs":[],"uses":["sauerkraut","kimchi"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["sauerkraut","kimchi"],"steps":[{"name":"Start seedlings under cover","process":"grow","text":"Plants begin in protected locations early in the growing season. Some growers seed directly into the field instead, where the crop will later be harvested.","inputs":[]},{"name":"Transplant to the field","process":"grow","text":"Seedlings go out into well-drained soil in full sun. About 90% of the root mass stays in the top 20 to 30 centimeters of soil.","inputs":[]},{"name":"Let the head close","process":"grow","text":"A rosette of 7 to 15 leaves spreads out first. After that, new leaves with shorter stems cup inward and tighten into a head. Most heads weigh 0.5 to 4 kilograms.","inputs":[]},{"name":"Cut below the leaves","process":"harvest","text":"A blade cuts the stalk just below the bottom leaves. Market cabbages are usually cut by hand, then trimmed, sorted and packed in the field, while machines handle much of the rest.","inputs":[]},{"name":"Store it cold","process":"chill","text":"At −1 to 2 °C and 90 to 100 percent humidity, heads keep for up to six months. Varieties grown for sauerkraut are larger and hold less water than market types.","inputs":[]}],"facts":["Dutch, Scandinavian and German sailors carried sauerkraut on long voyages to prevent scurvy.","Broccoli, kale and Brussels sprouts all come from the same species as cabbage.","The word cabbage traces back to a word for head, in the Picard dialect of Old French."],"where":[{"place":"China","share":"48% of world output"}],"whereNote":"Share of world cabbage production as stated on Wikipedia; the article text gives no year.","sources":[{"title":"Cabbage","url":"https://en.wikipedia.org/wiki/Cabbage"},{"title":"Head cabbage (Britannica)","url":"https://www.britannica.com/plant/cabbage"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"caffeine","name":"Caffeine","kind":"material","category":"chemicals","title":"How caffeine is made","url":"https://assemblyline.org/make/caffeine","stations":7,"upstream":10,"downstream":1,"depth":4,"dek":"Decaf makers do not throw the caffeine away. They recover it and sell it to soft drink companies.","answer":"Bags of white caffeine powder come from two places. Decaf plants pull it out of green coffee beans with water, solvent or carbon dioxide, ending with a crude product about 85% caffeine that still needs purifying. Chemical plants, with China the leading producer, build it through a long chain of reactions, then refine, crystallize, dry and mill it.","aka":["anhydrous caffeine","1,3,7-trimethylxanthine"],"inputs":["coffee-cherries","carbon-dioxide"],"uses":["energy-drink"],"grounds":["coffee-cherries","natural-gas","water","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["coffee-cherries","carbon-dioxide","natural-gas","water","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["energy-drink"],"steps":[{"name":"Steam the green beans","process":"wash","text":"Unroasted coffee beans are steamed or soaked before anything else happens. The extraction has to come before roasting, while the flavor precursors are still intact in the bean.","inputs":["coffee-cherries"]},{"name":"Flush with carbon dioxide","process":"separate","text":"Carbon dioxide under supercritical conditions is forced through the beans and carries the alkaloid out. Other plants rinse with an organic solvent, or soak in water and treat the water.","inputs":["carbon-dioxide"]},{"name":"Strip it from the carrier","process":"refine","text":"The caffeine is separated from whatever carried it. With an organic solvent, simple evaporation leaves it behind. Decaf plants treat this crude material as a second product to sell.","inputs":[]},{"name":"Purify the crude","process":"refine","text":"Crude caffeine from decaffeination is only about 85% caffeine, too impure for food or medicine. One patented process dissolves it in water, treats and filters the solution to take out impurities, and lets clean crystals form.","inputs":[]},{"name":"Or build it from scratch","process":"react","text":"Chemical plants also make caffeine with no coffee or tea involved. The main industrial route runs simple feedstocks through a long chain of reactions and filtering steps to a related compound, theophylline, and then to crude caffeine. A patent complains that the route is long and produces plenty of wastewater.","inputs":[]},{"name":"Refine, dry and mill","process":"refine","text":"Synthetic crude is refined, crystallized, filtered and dried, then granulated and pulverized into white powder. In its pure anhydrous form it melts at 235 to 238 °C.","inputs":[]},{"name":"Sell it onward","process":"package","text":"The powder is sold in USP, EP and FCC grades for food and medicine, generally at 99% purity or above. One market report puts beverages at 55% to 65% of demand and pharmaceuticals at 15% to 25%.","inputs":[]}],"facts":["The first commercial decaffeination process came about in 1903, after a shipment of coffee soaked in sea water turned out to have lost most of its caffeine.","A 12-ounce glass of cola holds about 40 mg of caffeine, against about 100 mg in an average cup of coffee.","Plants evolved caffeine separately in different species, an example of convergent evolution."],"where":[],"whereNote":null,"sources":[{"title":"Caffeine","url":"https://en.wikipedia.org/wiki/Caffeine"},{"title":"Decaffeination","url":"https://en.wikipedia.org/wiki/Decaffeination"},{"title":"Caffeine (Britannica)","url":"https://www.britannica.com/science/caffeine"},{"title":"Purification of caffeine (US4531003)","url":"https://patents.google.com/patent/US4531003"},{"title":"A kind of synthetic method of caffeine (CN112125903A)","url":"https://patents.google.com/patent/CN112125903A/en"},{"title":"Caffeine Manufacturing Plant Project Report (Procurement Resource)","url":"https://www.procurementresource.com/reports/caffeine-manufacturing-plant-project-report"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cake-mix","name":"Cake mix","kind":"product","category":"food","title":"How cake mix is made","url":"https://assemblyline.org/make/cake-mix","stations":6,"upstream":62,"downstream":0,"depth":9,"dek":"Bisquick began after a General Mills sales executive met a dining car chef who kept a premixed biscuit batter on hand.","answer":"Cake mix is a dry blend of flour, sugar, leavening agents such as baking soda and baking powder, salt and flavorings. Fat can be built into the mix as a dry shortening. A finishing machine grinds out any lumps, and the blend is sealed into pre-measured boxes or bags. The baker adds liquid and usually eggs.","aka":["boxed cake mix","baking mix"],"inputs":["flour","sugar","baking-soda","table-salt","vegetable-oil","cocoa-powder","cardboard","water","eggs"],"uses":[],"grounds":["water","eggs","wheat","sugarcane","sugar-beet","trona","limestone","rock-salt","seawater","soybeans","rapeseed","clay","cocoa-beans","air","natural-gas","corn","crude-oil","timber","sulfur","coal"],"upstreamSlugs":["flour","sugar","baking-soda","table-salt","vegetable-oil","cocoa-powder","cardboard","water","eggs","wheat","vitamin-c","sugarcane","sugar-beet","lime","trona","limestone","ammonia","rock-salt","soda-ash","carbon-dioxide","seawater","soybeans","rapeseed","hexane","clay","cocoa-beans","wood-pulp","adhesive","corn-starch","hydrogen","air","plastic-bottle","natural-gas","corn","yeast","crude-oil","timber","caustic-soda","oxygen","hydrogen-peroxide","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","pet-plastic","molasses","ethylene","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","p-xylene","ethylene-glycol","naphtha","sulfur","benzene","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Weigh the dry ingredients","process":"mix","text":"Flour, sugar and salt are weighed in bulk, and so are the leavening agents. Baking soda and baking powder are what make the batter rise in the oven.","inputs":["flour","sugar","baking-soda","table-salt"]},{"name":"Work in the shortening","process":"mix","text":"Shortening is mixed with part of the dry ingredients at a raised temperature to make a dry, flowable pre-mix. No more than about 25 percent of the flour goes in at this stage, which gives the best flavor and texture in the baked cake.","inputs":["vegetable-oil"]},{"name":"Blend until even","process":"mix","text":"A large blender turns the powders until the batch is uniform. Flavorings such as cocoa or vanilla can be added here.","inputs":["cocoa-powder"]},{"name":"Grind out the lumps","process":"grind","text":"Shortening can roll the powder into small pills, so the mix passes through a machine called a finisher, which grinds the product and breaks them up.","inputs":[]},{"name":"Pack pre-measured boxes","process":"fill","text":"The blend is measured into boxes or bags sized for a standard cake.","inputs":["cardboard"]},{"name":"Add liquid and bake","process":"bake","text":"At home the mix is stirred with water or milk, and usually eggs and oil, then baked. The oven heat sets the structure while the leavening agents release gas.","inputs":["water","eggs"]}],"facts":["Aunt Jemima pancake mix, made by the Pearl Milling Company in 1896, claims to be the first baking mix in the United States.","A complete mix needs only water or milk at home, while a concentrate needs more flour or other bulk added."],"where":[],"whereNote":null,"sources":[{"title":"Baking mix","url":"https://en.wikipedia.org/wiki/Cake_mix"},{"title":"Cake","url":"https://en.wikipedia.org/wiki/Cake"},{"title":"US patent 5,360,623: dry mix with shortening","url":"https://patents.google.com/patent/US5360623"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"drone","name":"Camera drone","kind":"product","category":"machines","title":"How camera drones are made","url":"https://assemblyline.org/make/drone","stations":7,"upstream":97,"downstream":0,"depth":9,"dek":"DJI kept its drone factory closed to outsiders for 14 years, until it released a video of the line in 2020.","answer":"The airframe comes first, cut or molded from carbon fiber, aluminum alloy or engineering plastic. Pick-and-place machines and soldering ovens build the boards, which go in with motors, battery and camera. Firmware is loaded, sensors are calibrated, and end-of-line tests follow. DJI's Mavic 2 Zoom line finishes with a test flight full of set maneuvers.","aka":["quadcopter","UAV","multirotor","camera drone"],"inputs":["nylon","carbon-fiber","printed-circuit-board","microchip","solder","copper-wire","electric-motor","polycarbonate","lithium-ion-cell","camera-sensor"],"uses":[],"grounds":["air","water","natural-gas","crude-oil","copper-ore","silica-sand","limestone","quartz","tin-ore","coal","gold-ore","lead-ore","silver-ore","zinc-ore","rock-salt","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","iron-ore","sulfur","trona","bauxite","dolomite","corn","timber","sugarcane","sugar-beet"],"upstreamSlugs":["nylon","carbon-fiber","printed-circuit-board","microchip","solder","copper-wire","electric-motor","polycarbonate","lithium-ion-cell","camera-sensor","benzene","nitric-acid","ammonia","propylene","air","copper","fiberglass","epoxy","photoresist","silicon-wafer","oxygen","tin","aluminum","gold","lead","silver","sheet-steel","ball-bearing","steel","phenol","acetone","caustic-soda","chlorine","lithium-carbonate","cobalt","nickel","manganese","synthetic-graphite","polyethylene","glass","naphtha","hydrogen","toluene","water","natural-gas","crude-oil","copper-ore","sulfuric-acid","silica-sand","limestone","soda-ash","phenolic-resin","polysilicon","quartz","argon","tin-ore","coke","coal","petroleum-coke","alumina","gold-ore","lime","zinc","lead-ore","silver-ore","zinc-ore","steel-wire","pig-iron","magnesium","steel-scrap","rock-salt","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","iron-ore","ethylene","sulfur","carbon-dioxide","trona","formaldehyde","silicon","hydrochloric-acid","trichlorosilane","nitrogen","bauxite","dolomite","propane","corn","yeast","methanol","charcoal","timber","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut and mold the frame","process":"mold","text":"Structural parts come first, in carbon fiber composite, aluminum alloy or engineering plastic. One factory guide lists CNC machines for cutting carbon fiber, along with injection molding machines and 3D printers. Tolerances stay tight, because the frame has to balance weight against strength.","inputs":["nylon","carbon-fiber"]},{"name":"Build the circuit boards","process":"assemble","text":"Pick-and-place machines set small parts on each board, then a reflow oven or wave soldering machine fixes them down. Automated optical inspection hunts for faults. These boards carry the processor and motion sensors that keep the aircraft steady.","inputs":["printed-circuit-board","microchip","solder"]},{"name":"Route the electronics","process":"assemble","text":"Flight controller, electronic speed controllers, power distribution, GPS and radio hardware all go into the airframe. The packing is dense, so cables and connectors are routed with care and left reachable for service.","inputs":["copper-wire"]},{"name":"Fit motors and propellers","process":"assemble","text":"Electric motors are mounted on the arms, each turning a propeller. Power system test benches and motor KV testers are standard equipment for checking this part of the drone.","inputs":["electric-motor","polycarbonate"]},{"name":"Install battery and camera","process":"assemble","text":"The battery pack goes in, followed by a camera or other payload. Payloads need exact positioning and calibration, or the data they collect will be off.","inputs":["lithium-ion-cell","camera-sensor"]},{"name":"Load firmware and calibrate","process":"inspect","text":"Firmware goes on, the flight controller is configured and the sensors are calibrated. Small errors here show up later as unstable flight or poor navigation. At DJI, Yaskawa robot arms moved Mavic 2 Zoom drones through parts of this stage.","inputs":[]},{"name":"Test and fly","process":"inspect","text":"End-of-line checks cover electronics, sensors, radio links, battery management and motors. DJI's line ends with a test flight. Its factories once relied on human pilots who tested every single drone.","inputs":[]}],"facts":["Designs with six or more rotors are more common on larger UAVs, where redundancy matters.","Small drones mostly use lithium-polymer batteries.","For small UAVs the quadcopter layout has become popular, though it is rarely used for crewed aircraft."],"where":[],"whereNote":null,"sources":[{"title":"Unmanned aerial vehicle","url":"https://en.wikipedia.org/wiki/Unmanned_aerial_vehicle"},{"title":"Electric motor","url":"https://en.wikipedia.org/wiki/Electric_motor"},{"title":"How Are Drones Manufactured? (HAHN Automation)","url":"https://www.hahnautomation.group/news/newsroom/how-are-drones-manufactured-key-production-steps-for-modern-uav-systems/"},{"title":"How to Build an FPV Drone Factory (Rich Full Joy)","url":"https://www.richpcba.com/blogs/guide-build-fpv-drone-factory-requirements-roadmap/"},{"title":"DJI factory tour: production DJI Mavic 2 shown in leaked video","url":"https://dronexl.co/2020/08/25/dji-factory-tour-production-mavic-2-leaked-video"},{"title":"A rare peek inside a DJI factory","url":"https://dronedj.com/2020/08/25/a-rare-peek-inside-a-dji-factory/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"camera-lens","name":"Camera lens","kind":"product","category":"electronics","title":"How camera lenses are made","url":"https://assemblyline.org/make/camera-lens","stations":6,"upstream":35,"downstream":1,"depth":8,"dek":"A camera lens is a stack of many glass elements, because no single curved piece of glass focuses cleanly.","answer":"A camera lens is a compound lens made up of many glass elements, because one simple lens cannot cancel the distortions that arise. Glass blanks are heated, pressed to a rough shape, then ground and polished to a curve. Elements get thin coatings, are centered in a metal barrel with the aperture, and are tested.","aka":["photographic lens","objective lens","zoom lens"],"inputs":["silica-sand","adhesive","aluminum","polycarbonate"],"uses":["digital-camera"],"grounds":["silica-sand","water","crude-oil","coal","bauxite","air","rock-salt","natural-gas","sulfur","limestone"],"upstreamSlugs":["silica-sand","adhesive","aluminum","polycarbonate","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","crude-oil","coal","petroleum-coke","alumina","phenol","propylene","acetone","caustic-soda","chlorine","ethylene","ammonia","sulfuric-acid","methanol","nitric-acid","hydrogen","bauxite","lime","benzene","air","naphtha","rock-salt","natural-gas","sulfur","limestone","toluene"],"downstreamSlugs":["digital-camera"],"steps":[{"name":"Melt the optical glass","process":"melt","text":"Sand and chemical additives are melted into optical glass with a carefully chosen refractive index. Different glass types bend different colors by different amounts, and designers combine them to cancel color fringes.","inputs":["silica-sand"]},{"name":"Press the glass blanks","process":"mold","text":"Softened glass is pressed to a rough lens shape in a mold. Some aspheric surfaces are molded straight to their final curve.","inputs":[]},{"name":"Grind and polish the curve","process":"grind","text":"Each blank is ground and polished with pads carrying hard grains, swapped several times for ever finer grit. The work usually takes hours, and the finer the finish wanted, the longer it runs.","inputs":[]},{"name":"Coat the surfaces","process":"deposit","text":"In a vacuum chamber, thin layers of material are laid down on each surface to cut reflections. Without coatings, light bouncing between the many surfaces would wash out contrast.","inputs":[]},{"name":"Center and cement the elements","process":"assemble","text":"Elements are aligned in groups on their optical axes and sometimes cemented together in pairs. Misalignment can blur one side of the picture.","inputs":["adhesive"]},{"name":"Mount in the barrel","process":"assemble","text":"The groups go into a barrel of machined aluminum or molded plastic along with the aperture blades and focus motor. Each lens is measured on a test bench before it leaves.","inputs":["aluminum","polycarbonate"]}],"facts":["Polishing a lens can take hours, while molding presses a heated glass preform to shape in hot tooling.","Diamond turning, used for complex shapes, needs no polishing afterward."],"where":[],"whereNote":null,"sources":[{"title":"Camera lens","url":"https://en.wikipedia.org/wiki/Camera_lens"},{"title":"Optical lens complete guide (Sinoptix)","url":"https://sinoptix.eu/2021/07/13/optical-lens-complete-guide"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"camera-sensor","name":"Camera sensor","kind":"product","category":"electronics","title":"How camera sensors are made","url":"https://assemblyline.org/make/camera-sensor","stations":6,"upstream":36,"downstream":4,"depth":7,"dek":"Half the colored filters over a camera sensor are green, to match how human eyes work.","answer":"A camera sensor is a silicon chip made on a wafer, like a processor. Each pixel gets a photodiode and transistors, and a checkerboard of red, green and blue filters is laid on top. Wafers are sawed into dies, and each die is mounted in a package under protective glass.","aka":["image sensor","CMOS sensor","CCD","digital camera chip"],"inputs":["silicon-wafer","copper","glass"],"uses":["smartphone","drone","satellite","digital-camera"],"grounds":["quartz","copper-ore","water","air","silica-sand","limestone","sulfur","rock-salt","trona","coal","timber","natural-gas","corn","sugarcane","sugar-beet"],"upstreamSlugs":["silicon-wafer","copper","glass","polysilicon","quartz","argon","copper-ore","water","oxygen","air","sulfuric-acid","silica-sand","soda-ash","limestone","silicon","hydrochloric-acid","trichlorosilane","hydrogen","nitrogen","sulfur","rock-salt","ammonia","carbon-dioxide","lime","trona","coke","coal","charcoal","timber","chlorine","natural-gas","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["smartphone","drone","satellite","digital-camera"],"steps":[{"name":"Build the pixel array","process":"etch","text":"Millions of pixels are patterned on a silicon wafer. Each has a pinned photodiode that collects light as charge and a few transistors to amplify it.","inputs":["silicon-wafer"]},{"name":"Wire the readout","process":"deposit","text":"Metal layers connect every pixel to row and column circuits, so the whole array can be read out line by line.","inputs":["copper"]},{"name":"Lay the color mosaic","process":"print","text":"A Bayer filter is laid over the pixels. It is half green, one quarter red and one quarter blue, so each pixel records just one color.","inputs":[]},{"name":"Probe and saw the wafer","process":"cut","text":"Dies are electrically tested, then separated by sawing.","inputs":[]},{"name":"Package under glass","process":"assemble","text":"Each die is wire-bonded into a package and sealed with a clear glass window.","inputs":["glass"]},{"name":"Check image quality","process":"inspect","text":"Sensors take test pictures so defective pixels can be mapped and corrected in software.","inputs":[]}],"facts":["Bryce Bayer's 1976 patent used twice as many green elements as red or blue to mimic the human eye.","The pinned photodiode was invented at NEC in 1980 and is used in nearly all CCD and CMOS sensors.","Each pixel records only one color, and the other two are filled in by interpolation."],"where":[],"whereNote":null,"sources":[{"title":"Image sensor","url":"https://en.wikipedia.org/wiki/Image_sensor"},{"title":"Active-pixel sensor","url":"https://en.wikipedia.org/wiki/Active-pixel_sensor"},{"title":"Bayer filter","url":"https://en.wikipedia.org/wiki/Bayer_filter"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"candle","name":"Candle","kind":"product","category":"play","title":"How candles are made","url":"https://assemblyline.org/make/candle","stations":7,"upstream":63,"downstream":0,"depth":10,"dek":"A candle's flame does not burn the wax. It melts it, and the wick draws it up as vapor to burn.","answer":"A candle is solid wax around a braided cotton wick. Most are paraffin, melted in a tank, mixed with dye and scent, and poured into molds or containers around a wick. As the wax cools it hardens, the candle is released, the wick is trimmed, and the candles are packed.","aka":["wax candle","taper","pillar candle"],"inputs":["paraffin-wax","cotton-yarn","thread","cardboard-box"],"uses":[],"grounds":["crude-oil","raw-cotton","water","natural-gas","timber","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","limestone","coal","sugar-beet"],"upstreamSlugs":["paraffin-wax","cotton-yarn","thread","cardboard-box","crude-oil","hydrogen","raw-cotton","polyester","water","cardboard","ink","adhesive","natural-gas","pet-plastic","wood-pulp","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","epoxy","polyurethane","p-xylene","ethylene","ethylene-glycol","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","propylene","ammonia","methanol","acetone","nitric-acid","naphtha","carbon-dioxide","rock-salt","limestone","benzene","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Melt the wax","process":"melt","text":"Paraffin wax, which begins to melt above about 37 °C, is heated in a jacketed tank until it flows like water.","inputs":["paraffin-wax"]},{"name":"Add color and scent","process":"mix","text":"Dye and fragrance are stirred into the melted wax. Hotter wax mixes quickly, while cooler wax holds scent better.","inputs":[]},{"name":"Braid the wick","process":"weave","text":"Cotton yarn is plaited into a wick. A plaited wick curls into the edge of the flame and burns away, so it trims itself.","inputs":["cotton-yarn"]},{"name":"Seat the wick in the mold","process":"assemble","text":"Each mold or jar gets a wick, held straight and centered by a metal tab or a clip.","inputs":["thread"]},{"name":"Pour the wax","process":"cast","text":"Warm wax is poured into the molds. Machines of the 19th century could make about 1,500 candles an hour by ejecting them with a piston as they set.","inputs":[]},{"name":"Cool and release","process":"chill","text":"The wax cools slowly so it does not crack, then candles are pushed out of the molds.","inputs":[]},{"name":"Trim and pack","process":"package","text":"Wicks are cut short, tops smoothed, and candles wrapped or boxed.","inputs":["cardboard-box"]}],"facts":["Joseph Morgan patented a continuous molding machine in 1834 that made about 1,500 candles an hour.","A plaited wick soaked in mineral salts, introduced in 1825, curls toward the edge of the flame and burns itself off.","Most candles today are made from paraffin wax, a petroleum byproduct."],"where":[],"whereNote":null,"sources":[{"title":"Candle","url":"https://en.wikipedia.org/wiki/Candle"},{"title":"Paraffin wax","url":"https://en.wikipedia.org/wiki/Paraffin_wax"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"candy-cane","name":"Candy cane","kind":"product","category":"food","title":"How candy canes are made","url":"https://assemblyline.org/make/candy-cane","stations":7,"upstream":49,"downstream":0,"depth":10,"dek":"Hand-made candy canes were once bent by workers, and over a fifth of them broke before a priest invented a machine for it.","answer":"Water, sugar and corn syrup boil to a thick yellow syrup. Peppermint and starch are kneaded in, and machines stretch the mass around a post until trapped air bubbles turn it white. Workers lay red stripes on a heavy log, rollers spin it thin, and belts twist in the spiral. Big factories cut and wrap the sticks before they bend them.","aka":["peppermint stick","stick candy"],"inputs":["sugar","corn-syrup","water","corn-starch","pigment","plastic-wrap"],"uses":[],"grounds":["water","sugarcane","sugar-beet","corn","iron-ore","sulfur","limestone","titanium-ore","crude-oil","air","rock-salt","coal","natural-gas","timber"],"upstreamSlugs":["sugar","corn-syrup","water","corn-starch","pigment","plastic-wrap","sugarcane","sugar-beet","lime","corn","iron-ore","titanium-dioxide","carbon-black","sulfur","pvc","polyethylene","cardboard","limestone","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","crude-oil","air","ethylene","plasticizer","wood-pulp","adhesive","rock-salt","coal","naphtha","natural-gas","propylene","timber","caustic-soda","hydrogen-peroxide","acrylic","epoxy","polyurethane","paraffin-wax","hydrogen","ammonia","methanol","phenol","acetone","nitric-acid","benzene","toluene"],"downstreamSlugs":[],"steps":[{"name":"Boil the syrup","process":"cook","text":"A batch of water, sugar and corn syrup boils down to a thick yellow syrup.","inputs":["sugar","corn-syrup","water"]},{"name":"Knead in the mint","process":"knead","text":"Mint flavor is mixed into starch and kneaded into the hot candy until the mass is even. A smaller batch is set aside and dyed dark red.","inputs":["corn-starch","pigment"]},{"name":"Stretch it white","process":"knead","text":"The mass is stretched again and again around a central pole. This forces in tiny air bubbles, and they scatter light, so yellow turns bright white.","inputs":[]},{"name":"Lay on the stripes","process":"laminate","text":"The white candy is packed into a log that can be as thick as a person's waist. Red bands go along it lengthwise, partly by hand, and workers in heat-resistant gloves handle hot tubes of 100 pounds.","inputs":[]},{"name":"Spin down and twist","process":"roll","text":"Rollers spin the log thinner, keeping its proportions, so the wide stripe shrinks to a fine line. Metal wheels move the rope along while special belts twist it into a spiral.","inputs":[]},{"name":"Cut and shrink-wrap","process":"cut","text":"The rope is cut into straight sticks that are wrapped in plastic while still warm.","inputs":["plastic-wrap"]},{"name":"Bend the crook","process":"mold","text":"In large-scale production the shepherd's hook comes last, formed after the stick is already wrapped. Factory canes tend to be thinner than handmade ones.","inputs":[]}],"facts":["Before automation, breakage often ran over 20 percent because the canes had to be bent by hand as they came off the line.","Gregory Harding Keller patented his twisting-and-cutting machine in 1957. He was an ordained Catholic priest working in his family's candy factory.","The popular story that a choirmaster in Cologne invented the shape in 1670 is likely apocryphal, as no references to it appear before the mid-20th century.","The earliest known appearance of the words candy cane is in an 1866 short story."],"where":[],"whereNote":null,"sources":[{"title":"Gizmodo: How are candy canes made?","url":"https://gizmodo.com/how-are-candy-canes-made-5866845"},{"title":"12 Tomatoes: An inside look at how candy canes are made","url":"https://12tomatoes.com/candy-cane-factory/"},{"title":"Sporked: How are candy canes made?","url":"https://sporked.com/?p=14552"},{"title":"Candy cane","url":"https://en.wikipedia.org/wiki/Candy_cane"},{"title":"Hard candy","url":"https://en.wikipedia.org/wiki/Hard_candy"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"candy-coated-chocolate","name":"Candy-coated chocolate","kind":"product","category":"food","title":"How candy-coated chocolates are made","url":"https://assemblyline.org/make/candy-coated-chocolate","stations":10,"upstream":49,"downstream":0,"depth":8,"dek":"The first big customer for M&M's was the U.S. Army, which wanted chocolate that would survive the tropics.","answer":"Candy-coated chocolates start as small centers tumbling in a rotating drum. Cold sugar syrup goes on, spreads over the rolling mass and dries under moving air, again and again, until a crystal shell has built up one thin coat at a time. Colored syrups go on near the end, and a ribbed pan buffs the pieces with wax.","aka":["panned chocolate","chocolate dragee","chocolate buttons"],"inputs":["chocolate","sugar","water","titanium-dioxide","carnauba","beeswax","ink"],"uses":[],"grounds":["water","carnauba","cocoa-beans","soybeans","sugarcane","sugar-beet","titanium-ore","honeycomb","raw-milk","limestone","rock-salt","coal","air","sulfur","rapeseed","clay","crude-oil","iron-ore","corn","natural-gas"],"upstreamSlugs":["chocolate","sugar","water","titanium-dioxide","carnauba","beeswax","ink","cocoa-beans","cocoa-butter","powdered-milk","soybeans","sugarcane","sugar-beet","lime","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","honeycomb","vegetable-oil","phenolic-resin","carbon-black","pigment","ethanol","raw-milk","limestone","rock-salt","coal","air","sulfur","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","iron-ore","corn","yeast","ethylene","hydrogen","benzene","propylene","methanol","molasses","naphtha","natural-gas","toluene"],"downstreamSlugs":[],"steps":[{"name":"Form the small centers","process":"mold","text":"Chocolate is shaped into small buttons, or a nut or other filling becomes the core. These centers would melt in warm weather without a shell.","inputs":["chocolate"]},{"name":"Prepare the surface","process":"coat","text":"Some cores first get gum-rich syrup alternated with fine sugar, which fills ridges and gives later coats something smooth to grip. A film of gelatin or gum can also block fat and water from moving between core and shell.","inputs":["sugar"]},{"name":"Spray on cold syrup","process":"coat","text":"Centers roll in a drum while spray guns wet them with sugar dissolved in water. Chocolate cannot take heat, so one panning patent gives about 27 °C for this stage. The mass keeps tumbling until the syrup has spread evenly.","inputs":["water"],"spec":"layers of 10 to 14 µm"},{"name":"Blow each coat dry","process":"dry","text":"Conditioned air flows through the drum and carries off the water, leaving a skin of tiny crystals. Every coat must dry fully before the next, since rushing makes the shell fail, so the work runs slowly.","inputs":[]},{"name":"Lay down color","process":"coat","text":"Titanium dioxide has long gone into precoat layers, giving an opaque white base so the colors above read true. Syrups carrying colorant then go on over it. One patent replaces the white pigment with sucrose esters.","inputs":["titanium-dioxide"]},{"name":"Finish with thin syrup","process":"coat","text":"Last coats use a weaker syrup, which dries more slowly and forms smaller, finer crystals. That is what makes the surface smooth enough to shine.","inputs":[]},{"name":"Rest on trays","process":"dry","text":"Pieces usually spend a night on trays in a climate-controlled room before polishing, though the syrup used can change that.","inputs":[]},{"name":"Polish with wax","process":"coat","text":"A ribbed pan works dry or liquid blends of carnauba and beeswax over the pieces. A confectioner's glaze can follow for protection, and glazed candy then airs for 18 to 24 hours so the solvent can leave.","inputs":["carnauba","beeswax"]},{"name":"Print the trademark","process":"print","text":"Each piece gets a letter printed on one side in edible ink. The printed mark has been part of M&M's since the early 1950s, first black and then white.","inputs":["ink"]},{"name":"Send to packing","process":"package","text":"Finished pieces leave the coating room and go to the packaging line.","inputs":[]}],"facts":["M&M's were likely inspired by Smarties, a British candy with a chocolate center and a hard sugar shell, which Forrest Mars may have seen soldiers eating in the Spanish Civil War.","During World War II the candies were sold only to the military."],"where":[],"whereNote":null,"sources":[{"title":"US5495418A, Automatic panning system","url":"https://patents.google.com/patent/US5495418/en"},{"title":"CA2903469C, Hard panned coating and confection comprising the same","url":"https://patents.google.com/patent/CA2903469C/en"},{"title":"Panning (food)","url":"https://en.wikipedia.org/wiki/Panning_(food)"},{"title":"M&M's","url":"https://en.wikipedia.org/wiki/M%26M%27s"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"canned-meat","name":"Canned meat","kind":"product","category":"food","title":"How canned meat is made","url":"https://assemblyline.org/make/canned-meat","stations":9,"upstream":76,"downstream":0,"depth":10,"dek":"Canned meat is cooked inside its own can, and the heat has to climb past 116 °C to kill botulism spores.","answer":"Grinders and mixers turn pork, ham or other meat into a seasoned paste with salt, water, starch and curing salt. Fillers load it into cans to a set weight, and a machine folds on the lid in a double seam. Washed cans go into retort baskets and cook under pressure above boiling, which kills botulism spores, then cool with care.","aka":["luncheon meat","tinned meat","potted meat"],"inputs":["pigs","table-salt","sugar","water","tin-can","cardboard-box"],"uses":[],"grounds":["pigs","water","rock-salt","seawater","sugarcane","sugar-beet","limestone","tin-ore","corn","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","timber","dolomite","manganese-ore","natural-gas","coal","quartz"],"upstreamSlugs":["pigs","table-salt","sugar","water","tin-can","cardboard-box","rock-salt","seawater","sugarcane","sugar-beet","lime","tinplate","lacquer","ink","cardboard","adhesive","limestone","steel","tin","ethanol","acrylic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","wood-pulp","polyethylene","epoxy","polyurethane","paraffin-wax","pig-iron","magnesium","steel-scrap","oxygen","manganese","argon","tin-ore","coke","corn","yeast","ethylene","propylene","ammonia","sulfuric-acid","methanol","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","iron-ore","sulfur","timber","caustic-soda","hydrogen-peroxide","acetone","nitric-acid","hydrogen","dolomite","silicon","propane","manganese-ore","natural-gas","coal","molasses","naphtha","benzene","quartz","charcoal","toluene"],"downstreamSlugs":[],"steps":[{"name":"Grind the pork","process":"crush","text":"Grinders, slicers and dicers reduce pork shoulder, ham or sometimes chicken or turkey. One famous canned meat was created to move a cut of pork that did not sell well.","inputs":["pigs"]},{"name":"Blend in the seasoning","process":"mix","text":"Mixers work salt, water, sugar and a binder such as potato starch through the meat. Sodium nitrite goes in as a preservative. Particle size and fat level both affect how heat will later move through the can.","inputs":["table-salt","sugar","water"]},{"name":"Fill to weight","process":"fill","text":"Fillers portion the paste into metal cans. Overfilling changes the headspace and how heat penetrates, so checkweighers watch the line.","inputs":["tin-can"]},{"name":"Pull a vacuum","process":"assemble","text":"Larger cans need a vacuum so pressure stays manageable in the cook. Canning plants use one of two methods: clinch the lid and heat the can in an exhaust box, or close it in a vacuum seamer.","inputs":[]},{"name":"Fold the double seam","process":"assemble","text":"A chuck grips the lid while it is crimped and interlocked with the can lip in two operations. The joint holds five layers of metal plus a sealing compound. An FAO canning guide asks for visual checks at least every 30 minutes.","inputs":[]},{"name":"Wash and load baskets","process":"wash","text":"A conveyor carries sealed cans through a washer with detergent and water, then drops them into retort baskets.","inputs":[]},{"name":"Cook in a pressure retort","process":"cook","text":"Baskets roll into a pressure vessel and heat well above boiling. Low-acid food like meat has to be sterilized this hot, because botulism spores survive plain boiling. Each product and can size needs its own schedule set by specialists.","inputs":[],"spec":"116 to 130 °C"},{"name":"Cool without denting","process":"chill","text":"Cans cool as gelatin forms from the meat and sets the filling into a block. The contents shrink, and the lids pull concave. Hot, wet cans are vulnerable, so rough conveyors and dirty cooling water can both ruin a seam.","inputs":[]},{"name":"Label and ship","process":"package","text":"Cans get inspected for dents and tilted ends, then labeled and boxed. They need no refrigeration.","inputs":["cardboard-box"]}],"facts":["Over 150 million pounds of Spam went to the US military during World War II.","Spam hit one billion cans in 1959, and sales have since passed nine billion.","A 109-year-old can of food from the wreck of the steamboat Bertrand showed no trace of microbial growth when tested in 1974."],"where":[],"whereNote":null,"sources":[{"title":"Canning processing, FAO","url":"https://www.fao.org/3/r6918e/R6918E05.HTM"},{"title":"Canned Meat Food Safety, Techik","url":"https://www.techikgroup.com/news/canned-meat-food-safety-where-production-risks-begin-and-how-processors-can-control-them/"},{"title":"Canned meat","url":"https://en.wikipedia.org/wiki/Canned_meat"},{"title":"Canning","url":"https://en.wikipedia.org/wiki/Canning"},{"title":"Spam (food)","url":"https://en.wikipedia.org/wiki/Spam_(food)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"canned-soup","name":"Canned soup","kind":"product","category":"food","title":"How canned soup is made","url":"https://assemblyline.org/make/canned-soup","stations":9,"upstream":63,"downstream":0,"depth":9,"dek":"Condensed soup has half its water taken out, so one can holds two cans' worth for the shopper to dilute at home.","answer":"Vegetables are washed, peeled, diced and blanched while stock simmers from bones and meat in steam-heated tanks. Everything is blended to a fixed formula with heat-stable starch, filled hot into cans with a little headspace and sealed with a double seam. Sealed cans go through a retort or steam tower that kills botulism spores, then cool quickly under controlled pressure. Condensed recipes leave out about half the water.","aka":["condensed soup","tinned soup"],"inputs":["chickens","water","tomatoes","corn-starch","tin-can"],"uses":[],"grounds":["chickens","water","tomatoes","corn","tin-ore","sugarcane","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","limestone","dolomite","manganese-ore","natural-gas","coal","rock-salt","quartz","timber","sugar-beet"],"upstreamSlugs":["chickens","water","tomatoes","corn-starch","tin-can","corn","tinplate","lacquer","ink","steel","tin","ethanol","acrylic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","tin-ore","coke","sugarcane","yeast","ethylene","propylene","ammonia","sulfuric-acid","methanol","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","iron-ore","sulfur","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","coal","molasses","naphtha","hydrogen","benzene","rock-salt","quartz","charcoal","timber","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Simmer the stock","process":"cook","text":"Bones and meat simmer in water in stainless steel tanks heated by steam. The broth stays separate until the blend.","inputs":["chickens","water"]},{"name":"Clean and dice vegetables","process":"cut","text":"Vegetables are steam cleaned, peeled and diced to an even size, since oversized pieces heat unevenly in the can later.","inputs":["tomatoes"]},{"name":"Blanch the pieces","process":"cook","text":"A short spell in hot water or steam at about 95 °C stops the enzymes that would spoil color and flavor before the cans are heated.","inputs":[]},{"name":"Blend to formula","process":"mix","text":"Solids, stock, salt and seasoning combine in a steam kettle or ribbon blender. Modified starch thickens the batch because it survives sterilizing heat without breaking down.","inputs":["corn-starch"]},{"name":"Fill the open cans","process":"fill","text":"Soup at 60 to 85 °C goes into coated steel cans, leaving a gap of air at the top. A jet of steam can clear that gap just before the lid goes on.","inputs":["tin-can"]},{"name":"Double seam the lids","process":"press","text":"A seamer folds the lid edge and can edge together twice to make an airtight seal. Cans are pulled off the line often so the seam can be measured.","inputs":[]},{"name":"Sterilize under pressure","process":"pasteurize","text":"Sealed cans ride through a retort, rotary cooker or hydrostatic tower of steam. The time is worked out per product so heat reaches the center and destroys botulism spores.","inputs":[],"spec":"110 to 130 °C"},{"name":"Cool the cans","process":"chill","text":"Treated water brings the cans down fast so the soup stops cooking. Pressure drops gradually at first, or hot cans would deform.","inputs":[]},{"name":"Label and pack","process":"package","text":"Cooled cans are labeled and cased for shipping.","inputs":[]}],"facts":["Sealed canned food typically lasts one to five years, and in special conditions much longer.","Andy Warhol painted a series of 32 canvases of soup cans in 1962."],"where":[],"whereNote":null,"sources":[{"title":"University of British Columbia FNH200: Canned soups","url":"https://wiki.ubc.ca/Course:FNH200/Projects/2021/Canned_Soups"},{"title":"Science Insights: How canned soup is made, ingredients to shelf life","url":"https://scienceinsights.org/how-canned-soup-is-made-ingredients-to-shelf-life/"},{"title":"Condensed soup","url":"https://en.wikipedia.org/wiki/Condensed_soup"},{"title":"Campbell Soup Company","url":"https://en.wikipedia.org/wiki/Campbell_Soup_Company"},{"title":"Canning","url":"https://en.wikipedia.org/wiki/Canning"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"canned-tuna","name":"Canned tuna","kind":"product","category":"food","title":"How canned tuna is made","url":"https://assemblyline.org/make/canned-tuna","stations":7,"upstream":38,"downstream":0,"depth":6,"dek":"Tuna is cooked twice, once whole before cleaning and again in the sealed can, and the can does the sterilizing.","answer":"Tuna caught by purse seine arrive frozen at a cannery and are thawed, then precooked whole for 1 1/2 hours to 10 hours depending on size. Workers clean the loins of bone, skin and dark meat, pack the pieces into cans with oil, water or brine, and seam the lid on. The sealed cans are cooked under pressure in a retort.","aka":["tinned tuna","tuna fish","chunk light tuna"],"inputs":["tuna-fish","tinplate","vegetable-oil","table-salt","water"],"uses":[],"grounds":["tuna-fish","water","soybeans","rapeseed","clay","rock-salt","seawater","tin-ore","crude-oil","iron-ore","limestone","air","dolomite","manganese-ore","natural-gas","coal","quartz","timber","sulfur"],"upstreamSlugs":["tuna-fish","tinplate","vegetable-oil","table-salt","water","steel","tin","soybeans","rapeseed","hexane","clay","rock-salt","seawater","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","tin-ore","coke","crude-oil","hydrogen","iron-ore","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","coal","quartz","charcoal","timber","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Net the school","process":"harvest","text":"Most tuna is caught with purse seine nets, which encircle a school of fish and are drawn shut underneath like a bag. The catch is frozen on board and unloaded at the cannery.","inputs":["tuna-fish"]},{"name":"Thaw and sort","process":"inspect","text":"Frozen fish are thawed in tanks and sorted by species and size. Tuna is often caught far from where it is canned, so poor handling in between can cause spoilage.","inputs":[]},{"name":"Precook the whole fish","process":"cook","text":"The fish are gutted and steamed in large cookers, from about 1 1/2 hours for small tuna to 8 to 10 hours for big ones. The cook firms the meat so it can be cleaned, and the fish lose roughly 22 to 26 percent of their weight as moisture runs out.","inputs":[],"spec":"1 1/2 to 10 hours"},{"name":"Clean the loins","process":"cut","text":"Cooled fish are cut into loins and cleaned by hand. Workers take off the skin, bones and dark lateral blood meat, which is often separated and used in cheaper products.","inputs":[]},{"name":"Pack the cans","process":"fill","text":"Machines cut the loins to can height and press them into steel cans. Then oil, water or brine is added, and in some cases sauce.","inputs":["tinplate","vegetable-oil","table-salt","water"]},{"name":"Seam the lids on","process":"weld","text":"A lid is rolled onto each can in a double seam that locks the metal edges together, so nothing can get in after sterilization.","inputs":[]},{"name":"Sterilize in a retort","process":"pasteurize","text":"Retort baskets of sealed cans go into a pressure cooker. Low-acid foods like fish need temperatures of 116 to 130 °C, which cannot be reached without pressure. This kills bacteria that would otherwise grow in the can.","inputs":[],"spec":"116 to 130 °C under pressure"}],"facts":["Nicolas Appert, the father of canning, began experimenting with preserving fish in jars in 1795.","The international standard sets a maximum histamine level of 200 milligrams per kilogram in canned tuna.","Tuna loses roughly a quarter of its weight in the precooker, before it is ever canned."],"where":[],"whereNote":null,"sources":[{"title":"Canned fish","url":"https://en.wikipedia.org/wiki/Canned_fish"},{"title":"Skipjack tuna","url":"https://en.wikipedia.org/wiki/Skipjack_tuna"},{"title":"Fish canning: processing","url":"https://www.fao.org/4/R6918E/R6918E05.htm"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"canoe","name":"Canoe","kind":"product","category":"play","title":"How canoes are made","url":"https://assemblyline.org/make/canoe","stations":7,"upstream":32,"downstream":0,"depth":7,"dek":"Composite canoes are built from the outside in: the glossy skin goes into the mold first.","answer":"Composite canoes grow inside a mold, starting with the outer skin. A gel coat is sprayed in, then workers lay fiberglass or Kevlar cloth by hand and saturate it with resin. Extra layers go where stress is highest, foam ribs or a core stiffen the hull, and surplus resin comes out. Wood trim, gunwales and seats finish the boat.","aka":["fiberglass canoe","paddling canoe"],"inputs":["polyester","fiberglass","kevlar","lumber"],"uses":[],"grounds":["silica-sand","limestone","timber","rock-salt","water","trona","natural-gas","air","sulfur","corn","crude-oil","sugarcane","sugar-beet"],"upstreamSlugs":["polyester","fiberglass","kevlar","lumber","pet-plastic","silica-sand","limestone","soda-ash","p-xylene","ammonia","chlorine","sulfuric-acid","timber","ethylene","ethylene-glycol","rock-salt","water","carbon-dioxide","lime","trona","naphtha","natural-gas","air","sulfur","oxygen","corn","yeast","crude-oil","hydrogen","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Build the mold","process":"mold","text":"At Hemlock, plans become a cedar strip prototype that gets paddled and altered until it is right. A mold is then taken from the prototype, and every hull comes from it.","inputs":[]},{"name":"Spray the outer skin","process":"coat","text":"A colored gel coat or clear coat goes into the mold first, and becomes the outside of the hull. Ultralight models skip it, which Clipper says saves about 10% of the weight.","inputs":["polyester"]},{"name":"Lay in the cloth","process":"laminate","text":"Workers place long strips of fiberglass or Kevlar cloth by hand and wet them with resin. Standard fiberglass boats use polyester resin, while Kevlar and premium hulls use a stronger vinyl ester.","inputs":["fiberglass","kevlar","polyester"]},{"name":"Reinforce the stress points","process":"laminate","text":"Partial layers go only where strain or impact is worst. Clipper puts at least two layers of Kevlar in the bow and stern of its fiberglass canoes.","inputs":["kevlar"]},{"name":"Stiffen the bottom","process":"laminate","text":"Foam cross ribs are resined to the hull and glassed over, or a foam core goes on the bottom under another layer of Kevlar. Either one stops the hull flexing up and down as it is paddled.","inputs":["fiberglass"]},{"name":"Remove the spare resin","process":"press","text":"On standard hulls a hand tool clears excess resin. Lighter layups use vacuum bagging or infusion, which leaves a better ratio of resin to cloth.","inputs":[]},{"name":"Pull and trim out","process":"assemble","text":"The finished hull comes out of the mold and gets wood trim, slotted gunwales, webbed seats and ash handles at bow and stern.","inputs":["lumber"]}],"facts":["The word canoe likely reached English from canoa, the name for a Caribbean dugout in Columbus's accounts from 1493.","A Kevlar canoe generally weighs 20% less than one made of fiberglass, according to the builder Clipper.","Plastic canoes that resist bending use a sandwich, with a thick foam core between two layers of polyethylene."],"where":[],"whereNote":null,"sources":[{"title":"Canoe","url":"https://en.wikipedia.org/wiki/Canoe"},{"title":"Building a Hemlock Canoe","url":"https://hemlockcanoe.com/construction/"},{"title":"Canoe Construction, Clipper Canoes","url":"https://www.clippercanoes.com/pages/canoe-construction"},{"title":"Canoe Materials and Manufacturing Processes, Frontenac Outfitters","url":"https://www.frontenacoutfitters.com/blogs/tutorials/canoe-materials-manufacturing-processes"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"car","name":"Car","kind":"product","category":"machines","title":"How cars are made","url":"https://assemblyline.org/make/car","stations":8,"upstream":124,"downstream":0,"depth":10,"dek":"In 1913 Ford cut a car's assembly time from 12.5 hours to 1 hour 33 minutes by moving the car past the workers.","answer":"A car begins as flat steel and aluminum sheet pressed into body panels, which robots weld into a shell. The shell is dipped, painted and baked, then rolls down an assembly line where engine, glass, wiring, seats and wheels are fitted. Each finished car is filled with fluids and tested before it leaves the plant.","aka":["automobile","passenger car","motor car"],"inputs":["sheet-steel","aluminum","paint","copper-wire","printed-circuit-board","windshield","airbag","carpet","polyurethane","car-engine","tire","gasoline"],"uses":[],"grounds":["crude-oil","coal","water","silica-sand","natural-latex","sulfur","zinc-ore","air","bauxite","titanium-ore","iron-ore","copper-ore","limestone","dolomite","fleece","rock-salt","natural-gas","corn","sugarcane","manganese-ore","trona","tin-ore","lead-ore","silver-ore","soybeans","rapeseed","clay","quartz","timber","gold-ore","sugar-beet"],"upstreamSlugs":["sheet-steel","aluminum","paint","copper-wire","printed-circuit-board","windshield","airbag","carpet","polyurethane","car-engine","tire","gasoline","steel","zinc","crude-oil","coal","petroleum-coke","alumina","water","titanium-dioxide","pigment","acrylic","tin-can","copper","fiberglass","epoxy","photoresist","solder","window-glass","ink","pvb","adhesive","nylon","silicone","thread","microchip","polypropylene","wool-yarn","propylene","nitric-acid","chlorine","pig-iron","silica-sand","synthetic-rubber","natural-latex","carbon-black","sulfur","steel-wire","brass","polyester","naphtha","hydrogen","ethanol","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","bauxite","caustic-soda","titanium-ore","coke","iron-ore","ammonia","methanol","tinplate","lacquer","copper-ore","limestone","soda-ash","phenol","acetone","phenolic-resin","tin","lead","silver","dolomite","nitrogen","vegetable-oil","polyvinyl-alcohol","plasticizer","polyethylene","paraffin-wax","benzene","silicon","hydrochloric-acid","silicon-wafer","gold","fleece","rock-salt","ethylene","styrene","pet-plastic","natural-gas","corn","sugarcane","yeast","propane","manganese-ore","carbon-dioxide","trona","formaldehyde","tin-ore","lead-ore","silver-ore","soybeans","rapeseed","hexane","clay","toluene","quartz","charcoal","timber","polysilicon","gold-ore","p-xylene","ethylene-glycol","molasses","trichlorosilane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Press the body panels","process":"stamp","text":"Giant presses close on flat sheet and bend it into doors, hoods, roofs and fenders in a single stroke. Many carmakers use steel for most panels and aluminum for a few lighter ones.","inputs":["sheet-steel","aluminum"]},{"name":"Weld the body shell","process":"weld","text":"Robots join hundreds of pressed pieces into one rigid shell, called the body-in-white. Modern shells include a steel safety cage around the passengers.","inputs":[]},{"name":"Dip and spray the shell","process":"coat","text":"The bare shell is lowered through baths that protect it from rust, then sprayed with colored paint and clear coat. Paint was once the slowest step on Ford's line, because only one type of black would dry fast enough.","inputs":["paint"]},{"name":"Install the wiring and electronics","process":"assemble","text":"A wiring loom is threaded through the body, then screens, sensors and control units are plugged in. A modern car carries many computers.","inputs":["copper-wire","printed-circuit-board"]},{"name":"Fit glass, seats and trim","process":"assemble","text":"Workers glue in the windshield, bolt in seats, lay carpet and clip the dashboard in place. Airbags are installed in the wheel, dash and doors.","inputs":["windshield","airbag","carpet","polyurethane"]},{"name":"Marry body to powertrain","process":"assemble","text":"The painted body, already fitted out inside, is lowered onto the engine, transmission and suspension, which have been built up on a separate line. Bolts at a handful of points hold the two together.","inputs":["car-engine"]},{"name":"Mount the wheels","process":"assemble","text":"Tires are fitted to wheels, balanced, and bolted on by a machine that tightens all the nuts at once.","inputs":["tire"]},{"name":"Fill up and road-test","process":"inspect","text":"The car receives fuel and fluids, starts for the first time, and is checked on rollers and a test track for leaks, rattles and alignment.","inputs":["gasoline"]}],"facts":["The world made 56 million cars in 2020, down from 67 million the year before.","Typical cars weigh between 1 and 3 tonnes, though the small Wuling Hongguang Mini EV weighs about 700 kilograms."],"where":[{"place":"China","share":"about 20 million cars"},{"place":"Japan","share":"about seven million cars"}],"whereNote":"2020, cars manufactured.","sources":[{"title":"Car","url":"https://en.wikipedia.org/wiki/Car"},{"title":"Windshield","url":"https://en.wikipedia.org/wiki/Windshield"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"car-battery","name":"Car battery","kind":"product","category":"machines","title":"How car batteries are made","url":"https://assemblyline.org/make/car-battery","stations":6,"upstream":18,"downstream":0,"depth":5,"dek":"A car battery is lead plates in dilute sulfuric acid, a design that dates to 1859.","answer":"A lead-acid car battery is built from grids of lead alloy cast and pasted with lead paste, which is cured so it hardens. The pasted plates, separated by thin plastic sheets, are stacked into cells inside a plastic case and joined with lead straps. The case is filled with sulfuric acid and charged.","aka":["lead-acid battery","12-volt battery","starter battery"],"inputs":["lead","sulfuric-acid","polyethylene","polypropylene","water"],"uses":[],"grounds":["water","lead-ore","sulfur","air","coal","zinc-ore","natural-gas","crude-oil"],"upstreamSlugs":["lead","sulfuric-acid","polyethylene","polypropylene","water","lead-ore","coke","zinc","sulfur","air","ethylene","propylene","coal","zinc-ore","naphtha","natural-gas","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Cast the grids","process":"cast","text":"Molten lead alloy is poured into molds that make a lattice, the grid that carries the current and holds the paste. Rough edges and casting gates are trimmed off once it cools.","inputs":["lead"]},{"name":"Paste the grids","process":"coat","text":"Lead is ground into an oxidized powder and mixed into a paste with dilute sulfuric acid. The paste is forced into the openings of each grid.","inputs":["lead","sulfuric-acid"]},{"name":"Cure the plates","process":"dry","text":"The pasted plates rest in a warm, humid chamber so the paste hardens and bonds to the grid.","inputs":[]},{"name":"Stack the cells","process":"assemble","text":"Positive and negative plates are interleaved, with a thin separator between each pair to stop them touching. Groups of plates are welded together with a lead strap.","inputs":["polyethylene"]},{"name":"Seal into the case","process":"assemble","text":"The cell stacks go into a plastic case, are connected in series, and the lid is heat-sealed on.","inputs":["polypropylene"]},{"name":"Fill and charge","process":"fill","text":"Dilute sulfuric acid is added and the battery is charged for the first time. That charge converts the paste into lead dioxide on the positive plates and spongy lead on the negative ones.","inputs":["sulfuric-acid","water"]}],"facts":["Gaston Planté's lead-acid cell was demonstrated in 1859, after Nicolas Gautherot noticed in 1801 that used wires gave a small secondary current.","When discharged, both plates turn into lead sulfate, and the acid turns mostly to water.","Battery makers treat their paste recipe as a top secret, since it holds the active material of the cell."],"where":[],"whereNote":null,"sources":[{"title":"Lead-acid battery","url":"https://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery"},{"title":"Casting","url":"https://en.wikipedia.org/wiki/Sand_casting"},{"title":"Production cycle of a sealed lead-acid battery","url":"https://dataweek.co.za/58744n"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"car-engine","name":"Car engine","kind":"product","category":"machines","title":"How car engines are made","url":"https://assemblyline.org/make/car-engine","stations":8,"upstream":42,"downstream":3,"depth":6,"dek":"Most of an engine is one lump of cast metal with holes bored in it, plus a crankshaft that turns piston pushes into spin.","answer":"A car engine begins as molten iron or aluminum poured into a mold to make the block and head. Machines bore the cylinders to a fine finish. Pistons, a crankshaft, valves and spark plugs are then fitted. Fuel burning in the cylinders pushes the pistons, and the crankshaft turns that back-and-forth push into spin.","aka":["internal combustion engine","petrol engine","gasoline engine"],"inputs":["pig-iron","aluminum","silica-sand","steel","gasoline"],"uses":["car","locomotive","motorcycle"],"grounds":["silica-sand","iron-ore","limestone","air","crude-oil","coal","bauxite","water","dolomite","manganese-ore","natural-gas","corn","sugarcane","rock-salt","quartz","timber","sulfur","sugar-beet"],"upstreamSlugs":["pig-iron","aluminum","silica-sand","steel","gasoline","iron-ore","coke","limestone","air","crude-oil","coal","petroleum-coke","alumina","magnesium","steel-scrap","oxygen","lime","manganese","argon","naphtha","hydrogen","ethanol","bauxite","caustic-soda","water","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","corn","sugarcane","yeast","ethylene","rock-salt","quartz","charcoal","timber","sulfur","molasses","sugar-beet"],"downstreamSlugs":["car","locomotive","motorcycle"],"steps":[{"name":"Pour the engine block","process":"cast","text":"Molten metal fills a sand mold shaped like the block, with hollow cores that become the water passages. Iron is cheap and wear-resistant. Aluminum is lighter, and its cylinders may be lined with iron or steel.","inputs":["pig-iron","aluminum","silica-sand"]},{"name":"Cast the cylinder head","process":"cast","text":"The head caps the block and holds the valves, the spark plugs and the passages that let air in and exhaust out.","inputs":["aluminum"]},{"name":"Bore the cylinders","process":"machine","text":"Cutting tools drill and bore each cylinder to size, and honing leaves a fine cross-hatch finish. The piston must slide in the cylinder with almost no gap.","inputs":[]},{"name":"Cast the pistons","process":"cast","text":"Small engines usually use aluminum pistons, while larger ones may use iron. Machines then cut the grooves that hold the sealing rings.","inputs":["aluminum"]},{"name":"Turn the crankshaft","process":"machine","text":"A steel crankshaft has an offset throw for every piston. Its journals are ground smooth to ride on bearings.","inputs":["steel"]},{"name":"Assemble the short block","process":"assemble","text":"The crankshaft drops into the block and is held by main bearings. Connecting rods then link each piston to it.","inputs":[]},{"name":"Mount the head and valves","process":"assemble","text":"The head goes on with a gasket between, then camshafts, valves and spark plugs. A timing belt or chain makes the camshaft turn in step with the crankshaft.","inputs":[]},{"name":"Fire it up on a test stand","process":"inspect","text":"Engines are run briefly with fuel and checked for leaks, pressure and noise before being sent to the car line.","inputs":["gasoline"]}],"facts":["Most spark-ignition engines use one spark plug per cylinder, though some use two.","Charles Kettering's electric self-starter, fitted to Cadillacs around 1910 and 1911, replaced the hand crank."],"where":[],"whereNote":null,"sources":[{"title":"Internal combustion engine","url":"https://en.wikipedia.org/wiki/Internal_combustion_engine"},{"title":"Crankshaft","url":"https://en.wikipedia.org/wiki/Crankshaft"},{"title":"Car","url":"https://en.wikipedia.org/wiki/Car"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"caramel","name":"Caramel","kind":"product","category":"food","title":"How caramel candy is made","url":"https://assemblyline.org/make/caramel","stations":5,"upstream":26,"downstream":0,"depth":6,"dek":"Salt goes in last, because added early it would break the sugar down as it cooked.","answer":"Caramel candy is cooked from sugar, glucose syrup, cream and butter. The sugars are heated first, then the dairy is added, which cools the pot, and the mixture is stirred and reheated to a firm-ball temperature of 120 degrees Celsius. Vanilla and salt go in at the end, because heat would burn off the flavor.","aka":["caramels","milk caramel","chewy caramel"],"inputs":["sugar","corn-syrup","pasteurized-milk","butter","cream","vanilla-extract","table-salt"],"uses":[],"grounds":["sugarcane","sugar-beet","water","corn","raw-milk","vanilla-pods","rock-salt","seawater","limestone","natural-gas","crude-oil"],"upstreamSlugs":["sugar","corn-syrup","pasteurized-milk","butter","cream","vanilla-extract","table-salt","sugarcane","sugar-beet","water","lime","corn","corn-starch","raw-milk","vanilla-pods","ethanol","rock-salt","seawater","limestone","yeast","ethylene","molasses","naphtha","natural-gas","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Heat the sugars","process":"cook","text":"Sugar and glucose are combined and heated to 130 degrees Celsius. The glucose, from corn syrup or wheat, stops the sugar from crystallizing into grit later.","inputs":["sugar","corn-syrup"],"spec":"130 °C"},{"name":"Pour in the dairy","process":"mix","text":"Cream and butter go into the hot syrup. The cold dairy drops the temperature of the whole pot.","inputs":["pasteurized-milk","butter","cream"]},{"name":"Stir and reheat","process":"cook","text":"The batch is stirred and brought back up to 120 degrees Celsius, the firm ball stage. Staying below the heat of full caramelization lets the milk itself brown and gives milk caramel its flavor.","inputs":[],"spec":"120 °C"},{"name":"Add flavor last","process":"mix","text":"Vanilla and salt are stirred in at the end. Vanilla added earlier would burn off, and salt added earlier would invert the sugars as they cooked.","inputs":["vanilla-extract","table-salt"]},{"name":"Cool and cut","process":"cut","text":"The thick mass is left to cool until it is firm enough to slice into pieces.","inputs":[]}],"facts":["The brown color of caramel comes from three groups of polymers that form as sugar breaks down, and the buttery smell comes partly from diacetyl.","A 1977 salted butter caramel from Quiberon in Brittany was named best confectionery in France in 1980.","Caramel coloring is sugar taken to near-total caramelization, and it is what makes cola brown."],"where":[],"whereNote":null,"sources":[{"title":"Caramel","url":"https://en.wikipedia.org/wiki/Caramel"},{"title":"Caramelization","url":"https://en.wikipedia.org/wiki/Caramelization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"caramel-color","name":"Caramel color","kind":"material","category":"food","title":"How caramel color is made","url":"https://assemblyline.org/make/caramel-color","stations":5,"upstream":15,"downstream":3,"depth":3,"dek":"The brown in cola is sugar cooked well past the candy caramel stage.","answer":"Caramel color is sugar that has been cooked well past candy caramel. Makers heat a sweetener such as dextrose, sucrose or molasses, sometimes with acids, alkalis or salts, until it turns amber to dark brown and dissolves in water. It is one of the oldest and most used food colorings.","aka":["E150","caramel coloring","burnt sugar color"],"inputs":["sugar","corn-syrup","molasses","malted-barley","ammonia"],"uses":["cola","rum","soda"],"grounds":["sugarcane","sugar-beet","water","corn","barley","natural-gas","air","limestone"],"upstreamSlugs":["sugar","corn-syrup","molasses","malted-barley","ammonia","sugarcane","sugar-beet","water","lime","corn","corn-starch","barley","natural-gas","air","limestone"],"downstreamSlugs":["cola","rum","soda"],"steps":[{"name":"Pick a sugar base","process":"mix","text":"Makers start with a nutritive sweetener such as dextrose, sucrose, invert sugar, malt syrup, molasses or a starch hydrolysate.","inputs":["sugar","corn-syrup","molasses","malted-barley"]},{"name":"Match charge to the drink","process":"mix","text":"Acids, alkalis or salts, some of them ammonia compounds, decide which of four classes comes out and whether the molecules carry a positive or negative charge. A matching charge keeps a drink from clouding or settling.","inputs":["ammonia"]},{"name":"Cook the charged mixture","process":"cook","text":"Heat is applied to the sugar and its reactant until the batch turns amber to dark brown. Some classes of caramel color are cooked from sugar alone.","inputs":[]},{"name":"Tune the color strength","process":"inspect","text":"Color strength is measured by how much light a 1 mg per mL solution absorbs at 610 nanometers. Batches are adjusted so a drink looks the same every time.","inputs":[]},{"name":"Pack as a liquid","process":"fill","text":"The finished color is a dark, water-soluble liquid. It goes out in drums and tanks to brewers and soft drink makers.","inputs":[]}],"facts":["The first recorded large-scale use of caramel color was in 19th century brewing.","Caramel color has a burnt-sugar smell and a slightly bitter taste.","Caramel color is used to correct natural variations in color and to replace color lost to light during processing."],"where":[],"whereNote":null,"sources":[{"title":"Caramel color","url":"https://en.wikipedia.org/wiki/Caramel_color"},{"title":"Molasses","url":"https://en.wikipedia.org/wiki/Molasses"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"carbon-black","name":"Carbon black","kind":"material","category":"chemicals","title":"How carbon black is made","url":"https://assemblyline.org/make/carbon-black","stations":5,"upstream":3,"downstream":200,"depth":1,"dek":"Carbon black is soot made on purpose, and about 70% of it goes into tires.","answer":"Carbon black is made by spraying heavy oil into a very hot reactor with too little air for the oil to burn completely. The oil breaks down into tiny carbon particles. A water spray cools the smoke, bag filters catch the black powder, and a pelletizer rolls it into beads so it can be shipped without dust.","aka":["furnace black","lamp black","acetylene black"],"inputs":["crude-oil","air","water"],"uses":["mascara","rubber","ink","aa-battery","tire","hockey-puck","tungsten-carbide","printer-toner","hiking-boots","rubber-boots","vinyl-record","remote-control","pigment"],"grounds":["crude-oil","air","water"],"upstreamSlugs":["crude-oil","air","water"],"downstreamSlugs":["mascara","rubber","ink","aa-battery","tire","hockey-puck","tungsten-carbide","printer-toner","hiking-boots","rubber-boots","vinyl-record","remote-control","pigment","computer-keyboard","vacuum-cleaner","electric-kettle","pencil","shipping-container","tennis-ball","baseball","soccer-ball","ski","snowboard","roller-skates","golf-club","football","volleyball","cricket-bat","dumbbell","treadmill","wheelchair","ladder","wheelbarrow","fire-extinguisher","high-heels","loudspeaker","inkjet-printer","electric-toothbrush","sneaker","leather-shoe","umbrella","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","basketball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flip-flops","flag","compact-disc","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","car","electric-car","bicycle","motorcycle","saw-blade","toothbrush","lipstick","nail-polish","pvc","abs-plastic","paint","lego-brick","lcd-screen","porcelain","chalk","candy-cane","sprinkles","crayon","plastic-straw","pencil-eraser","billiard-ball","foundation-makeup","eyeshadow","eyeglass-frame","towel","laptop","cotton-candy","pillow","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","soap","toothpaste","detergent","nitrile-glove","washing-machine","paperclip","donut","corn-flakes","popcorn","fireworks","candle","salsa","fish-sticks","zip-bag","blender","dishwasher","cotton-swab","mouthwash","cough-syrup","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","facial-tissue","envelope","plastic-wrap","garden-hose","yoga-mat","action-figure","fashion-doll","inflatable-pool-toy","chain-link-fence","pvc-pipe","power-cable","usb-cable","hearing-aid","thermometer","3d-printer-filament","television","computer-mouse","headphones","harmonica","suitcase","phone-charger","e-reader","graphics-card","refrigerator","microwave-oven","scissors","mirror","airplane","container-ship","locomotive","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","fishing-rod","bowling-ball","dartboard","dice","snow-globe","toy-car","coil-spring","hammer","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","smartwatch","digital-camera","toffee","padlock"],"steps":[{"name":"Preheat the heavy oil","process":"melt","text":"Heavy oil left over from refining or ethylene cracking is warmed until it flows easily. The more aromatic the oil, the more carbon black it yields.","inputs":["crude-oil"]},{"name":"Spray it into a starved flame","process":"react","text":"The oil is atomized into a reactor whose walls are glowing hot, with a limited supply of air. With too little oxygen to burn, the droplets crack into particles of carbon.","inputs":["air"]},{"name":"Quench the smoke","process":"chill","text":"A spray of water stops the reaction at exactly the right moment. When the quench comes decides how big the particles are.","inputs":["water"]},{"name":"Filter the black from the gas","process":"separate","text":"The smoke passes through cyclones and bag filters that catch the fluffy black powder. The leftover gas is often burned to make power.","inputs":[]},{"name":"Bead and dry the powder","process":"mix","text":"Fluffy powder is tumbled with water in a pelletizer so it clumps into small beads, which are then dried. Beads flow cleanly and do not make clouds of dust.","inputs":[]}],"facts":["Carbon black also helps conduct heat away from the tread of a tire and extends its life.","Lamp black, the oldest form, was made by collecting soot from oil lamps."],"where":[],"whereNote":null,"sources":[{"title":"Carbon black","url":"https://en.wikipedia.org/wiki/Carbon_black"},{"title":"Natural rubber","url":"https://en.wikipedia.org/wiki/Natural_rubber"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"carbon-dioxide","name":"Carbon dioxide","kind":"material","category":"chemicals","title":"Where industrial carbon dioxide comes from","url":"https://assemblyline.org/make/carbon-dioxide","stations":5,"upstream":8,"downstream":265,"depth":3,"dek":"Less than 1 percent of the carbon dioxide people produce is put to use, mostly in fertilizer plants and oil wells.","answer":"Industrial carbon dioxide is mostly caught as a by-product of something else: hydrogen and ammonia plants, brewery fermentation vats, and lime kilns. The gas is cleaned and cooled into a liquid, which goes into fizzy drinks, welding, greenhouses and fire extinguishers. Frozen solid, it becomes dry ice.","aka":["CO2","dry ice","carbonic gas"],"inputs":["natural-gas","water","corn","yeast","limestone"],"uses":["aspirin","soda-ash","fertilizer","baking-soda","decaf-coffee","cola","sparkling-water","beer","refrigerant","popping-candy","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","caffeine","melamine-resin","ethylene-glycol"],"grounds":["natural-gas","water","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["natural-gas","water","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["aspirin","soda-ash","fertilizer","baking-soda","decaf-coffee","cola","sparkling-water","beer","refrigerant","popping-candy","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","caffeine","melamine-resin","ethylene-glycol","detergent","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","instant-noodles","stained-glass","vanadium","pretzel","frozen-pizza","bagel","crackers","cake-mix","fire-extinguisher","refrigerator","air-conditioner","asthma-inhaler","laminate-floor","pet-plastic","spandex","printed-circuit-board","wind-turbine","surfboard","ski","snowboard","fishing-rod","kite","roof-shingle","vinyl-floor","canoe","sailboat","umbrella","lithium-ion-cell","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather","thermometer","lcd-screen","oled-screen","camera-sensor","solar-panel","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","floor-tile","neon-sign","smartwatch","e-reader","mirror","skyscraper","windshield","double-glazed-window","nail-polish","perfume","penicillin","insulin","vaccine","ketchup","wine","champagne","whiskey","vodka","gin","rum","tequila","sake","hard-cider","hot-sauce","kombucha","bourbon","scotch","cognac","mezcal","mead","port-wine","prosecco","smartphone","polyester","plastic-bottle","credit-card","3d-printer-filament","drum-kit","bottled-water","underwear","leggings","swimsuit","hearing-aid","pacemaker","led-bulb","ev-battery","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","washing-machine","drone","satellite","car","electric-car","airbag","airplane","rocket","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","smoke-detector","wireless-earbuds","phone-charger","digital-camera","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","syringe","electric-kettle","kitchen-knife","fork","fountain-pen","thermos","water-bottle","pressure-cooker","dishwasher","golf-club","subway-train","jet-engine","baseball","basketball","tennis-racket","football","saxophone","winter-gloves","leather-belt","handbag","wallet","hiking-boots","high-heels","leather-shoe","eyeglass-frame","mustard","salsa","pickles","sauerkraut","jam","hazelnut-spread","aluminum-window-frame","shampoo","deodorant","air-freshener","dish-soap","hairspray","foundation-makeup","tire","soccer-ball","marker-pen","highlighter","sofa","office-chair","pillow","garden-hose","volleyball","kitchen-sponge","wet-wipes","seat-belt","hoodie","raincoat","backpack","suitcase","shoelace","curtain","flag","microphone","sneaker","mattress","zipper","button","thread","teddy-bear","sunscreen","bleach","vitamin-c","hair-dye","mouthwash","cough-syrup","mayonnaise","bicycle","down-jacket","jeans","dress-shirt","suit","baseball-cap","fireworks","bike-helmet","candle","yo-yo","fashion-doll","tampon","silk-tie","felt-hat","blanket","book","t-shirt","socks","sweater","towel","flour","bread","tortilla","croissant","donut","sandwich-cookie","chicken-nuggets","baguette","sourdough","fish-sticks","modeling-clay","licorice"],"steps":[{"name":"Capture it from a reformer","process":"react","text":"Making hydrogen from natural gas and steam gives carbon dioxide as a by-product. Ammonia plants add a second round through the water gas shift reaction.","inputs":["natural-gas","water"]},{"name":"Catch it at the brewery","process":"ferment","text":"Yeast turns sugar into ethanol and carbon dioxide. Breweries and bioethanol plants collect the gas from the vats instead of letting it escape.","inputs":["corn","yeast"]},{"name":"Bake limestone in a kiln","process":"fire","text":"Heating limestone drives off carbon dioxide and leaves quicklime. The kiln gas is a third source.","inputs":["limestone"],"spec":"about 850 °C"},{"name":"Clean and liquefy the gas","process":"chill","text":"The captured gas is cleaned and cooled under pressure to a liquid. Carbon dioxide cannot be liquid below about 5 atmospheres.","inputs":[]},{"name":"Press it into dry ice","process":"press","text":"Some liquid is allowed to expand, which freezes it into snow that is pressed into blocks. Dry ice turns straight to gas at normal pressure instead of melting.","inputs":[]}],"facts":["Solid carbon dioxide skips the liquid stage at normal pressure, which is why it is called dry ice.","Greenhouse crops photosynthesize about 50 percent faster at 1,000 ppm carbon dioxide than at 340 ppm."],"where":[],"whereNote":null,"sources":[{"title":"Carbon dioxide","url":"https://en.wikipedia.org/wiki/Carbon_dioxide"},{"title":"Industrial gas","url":"https://en.wikipedia.org/wiki/Industrial_gas"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"carbon-fiber","name":"Carbon fiber","kind":"material","category":"plastics","title":"How carbon fiber is made","url":"https://assemblyline.org/make/carbon-fiber","stations":6,"upstream":8,"downstream":10,"depth":4,"dek":"Carbon fiber is a plastic thread baked until everything but the carbon has been driven out of it.","answer":"Carbon fiber is made from a plastic precursor, usually polyacrylonitrile. The plastic is spun into filament yarns that are stretched to align the chains, then heated in stages so that all non-carbon atoms are driven off. What is left is a thread of nearly pure carbon, about 5 to 7 micrometers thick, which is coated and wound on spools.","aka":["graphite fiber","CFRP"],"inputs":["propylene","ammonia","air"],"uses":["wind-turbine","drone","satellite","airplane","bicycle","tennis-racket","golf-club","fishing-rod","kite","prosthetic-leg"],"grounds":["air","crude-oil","natural-gas","water"],"upstreamSlugs":["propylene","ammonia","air","naphtha","crude-oil","natural-gas","water","hydrogen"],"downstreamSlugs":["wind-turbine","drone","satellite","airplane","bicycle","tennis-racket","golf-club","fishing-rod","kite","prosthetic-leg"],"steps":[{"name":"Make the acrylic precursor","process":"react","text":"Propylene and ammonia are converted to acrylonitrile, which is polymerized into polyacrylonitrile, or PAN. This plastic is the raw material for most carbon fiber.","inputs":["propylene","ammonia"]},{"name":"Spin it into filament","process":"spin","text":"PAN solution is pushed through spinnerets into a coagulating bath, forming bundles of filaments. Stretching the yarn aligns the polymer chains, which gives the finished fiber its strength.","inputs":[]},{"name":"Stabilize it in air","process":"heat-treat","text":"Filaments pass slowly through ovens full of hot air. The chains rearrange into a heat-proof form, and the fiber turns from white to black.","inputs":["air"]},{"name":"Carbonize it without oxygen","process":"heat-treat","text":"In a furnace filled with inert gas, the fiber is heated until nitrogen, hydrogen and oxygen atoms leave. Only tightly bonded sheets of carbon atoms remain.","inputs":[]},{"name":"Treat and size the surface","process":"coat","text":"The fiber is lightly oxidized so resin can grip it, then coated in a thin protective sizing. This helps the fiber bond with epoxy later.","inputs":[]},{"name":"Wind it onto spools","process":"package","text":"Thousands of filaments are bundled into a tow and wound onto spools. Weavers and composite makers buy it as tow or as woven cloth.","inputs":[]}],"facts":["The Airbus A350 XWB is 53% carbon fiber reinforced polymer by weight, including wing spars and fuselage parts.","Carbon fiber can be made from polyacrylonitrile, rayon or petroleum pitch."],"where":[],"whereNote":null,"sources":[{"title":"Carbon fiber reinforced polymer","url":"https://en.wikipedia.org/wiki/Carbon_fiber_reinforced_polymer"},{"title":"Polyacrylonitrile","url":"https://en.wikipedia.org/wiki/Polyacrylonitrile"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"carbon-monoxide","name":"Carbon monoxide","kind":"material","category":"chemicals","title":"How carbon monoxide is made","url":"https://assemblyline.org/make/carbon-monoxide","stations":6,"upstream":2,"downstream":9,"depth":1,"dek":"Factories make this poison on purpose, because acetic acid, polyurethane and plenty of other chemicals start with it.","answer":"Natural gas and steam pass through catalyst-filled tubes inside a furnace and come out as synthesis gas, a mix of hydrogen and carbon monoxide. Plants wash out the carbon dioxide and send it back to the furnace, which raises the yield. A cold box or a set of adsorbent beds then splits the two main gases apart.","aka":["CO"],"inputs":["natural-gas","water"],"uses":["acetic-anhydride"],"grounds":["natural-gas","water"],"upstreamSlugs":["natural-gas","water"],"downstreamSlugs":["acetic-anhydride","aspirin","acetaminophen","ibuprofen","cellulose-acetate","sunglasses","dice","shoelace","eyeglass-frame"],"steps":[{"name":"Pre-reform the feed gas","process":"refine","text":"Natural gas carries heavier hydrocarbons such as propane and butane. A pre-reformer breaks those down to methane, which gives the main furnace a simpler and more efficient feed.","inputs":["natural-gas"]},{"name":"Crack methane with steam","process":"react","text":"Steam and methane flow through long, narrow tubes packed with nickel catalyst, shaped like spoked wheels or holed rings. Burners in the surrounding furnace keep supplying heat, since the reaction swallows it. Out comes hydrogen and the gas this plant wants.","inputs":["water"],"spec":"800 to 900 °C at 20 to 30 bar"},{"name":"Recycle the carbon dioxide","process":"react","text":"Carbon dioxide returned to the furnace reacts with methane too. That leaves more carbon and less steam in the tubes, so the outlet gas holds a higher concentration of the product.","inputs":[]},{"name":"Scrub with amine solution","process":"wash","text":"The gas rises through an absorber while an amine solution falls against it and grabs the carbon dioxide. A regenerator strips the solution for reuse, and the freed carbon dioxide gets recompressed for the trip back to the furnace.","inputs":[]},{"name":"Split off the hydrogen","process":"separate","text":"The impure stream now enters a cold box or a pressure swing adsorption system. In the adsorption route, beds of molecular sieve hold back the more strongly adsorbed gas under pressure while hydrogen slips through the far end.","inputs":[]},{"name":"Depressurize the adsorbent beds","process":"separate","text":"Dropping the pressure lets the trapped gas back out. One patented cycle first displaces leftover hydrogen from the bed, then releases product at 1-2 bar and purges a carbon dioxide-rich waste gas that returns to the furnace.","inputs":[],"spec":"99% purity in one patented cycle"}],"facts":["Sunlight breaking down plant matter is estimated to release 60 million tons of carbon monoxide a year.","In the US, some fresh beef, pork and fish is sealed in packaging containing carbon monoxide to keep it looking fresh.","Aristotle recorded that burning coals give off toxic fumes more than two thousand years before anyone isolated the gas."],"where":[],"whereNote":null,"sources":[{"title":"US4726816A, Reformer-pressure swing adsorption process for the production of carbon monoxide","url":"https://patents.google.com/patent/US4726816A/en"},{"title":"Steam reforming","url":"https://en.wikipedia.org/wiki/Steam_reforming"},{"title":"Syngas","url":"https://en.wikipedia.org/wiki/Syngas"},{"title":"Carbon monoxide","url":"https://en.wikipedia.org/wiki/Carbon_monoxide"},{"title":"Amine gas treating","url":"https://en.wikipedia.org/wiki/Amine_gas_treating"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cardboard","name":"Cardboard","kind":"material","category":"wood-paper","title":"How cardboard is made","url":"https://assemblyline.org/make/cardboard","stations":6,"upstream":33,"downstream":59,"depth":8,"dek":"Corrugated cardboard is two flat sheets of paper with a wavy one glued between them, held together with starch.","answer":"Cardboard is heavy paper. The corrugated kind used for shipping is a sandwich: a wavy sheet called the medium, made by steaming and pressing paper on geared wheels, is glued between two flat sheets called liners. The sandwich runs through a long machine called a corrugator, which dries it under hot plates before it is cut to size.","aka":["corrugated board","corrugated fiberboard","corrugate","paperboard"],"inputs":["wood-pulp","water","adhesive"],"uses":["toothbrush","duct-tape","fireworks","plastic-wrap","clear-tape","board-game","jigsaw-puzzle","trading-cards","cake-mix","soda","energy-drink","hair-dye","tampon","cardboard-box","toilet-paper","book","playing-cards","match","leather-shoe"],"grounds":["water","timber","rock-salt","limestone","air","crude-oil","natural-gas","sulfur","coal"],"upstreamSlugs":["wood-pulp","water","adhesive","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","rock-salt","limestone","air","hydrogen","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","natural-gas","naphtha","sulfur","benzene","toluene","coal"],"downstreamSlugs":["toothbrush","duct-tape","fireworks","plastic-wrap","clear-tape","board-game","jigsaw-puzzle","trading-cards","cake-mix","soda","energy-drink","hair-dye","tampon","cardboard-box","toilet-paper","book","playing-cards","match","leather-shoe","aa-battery","popcorn","candy-cane","soap","toothpaste","deodorant","detergent","plastic-bag","nitrile-glove","washing-machine","vacuum-cleaner","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","blender","dishwasher","pillow","cotton-swab","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","sticky-notes","syringe"],"steps":[{"name":"Press out the board stock","process":"cast","text":"Thick sheets of kraft paperboard or recycled fiber are made on a paper machine. These are the liners and the wavy middle layer, and they are all stronger than ordinary writing paper.","inputs":["wood-pulp","water"]},{"name":"Steam it into waves","process":"mold","text":"At the single-facer, the middle sheet is heated, moistened and pushed between two geared wheels. The teeth squeeze it into a row of folds, called flutes, that run across the roll.","inputs":[]},{"name":"Glue the first liner on","process":"laminate","text":"Starch-based glue is applied to the tips of the waves on one side, and a flat liner is pressed against them. This one-sided board is called single face.","inputs":["adhesive"]},{"name":"Glue the second liner on","process":"laminate","text":"At the double-backer, a second flat liner meets the other side of the waves. The result is single-wall corrugated board with an arrangement of air channels sealed inside.","inputs":["adhesive"]},{"name":"Dry under hot plates","process":"dry","text":"The new board is carried along a belt over heated plates while weights press down from above. This sets the glue and keeps the board from warping or developing ripples.","inputs":[]},{"name":"Slit to size","process":"cut","text":"Knives trim the edges and slit the wide board into sheets of the width the order calls for. Double-wall and triple-wall board repeat the sandwich for heavier loads.","inputs":[],"spec":"150 m/min or more"}],"facts":["Corrugated paper was first patented in England in 1856, to line tall hats, and it was not used for shipping until Albert Jones of New York patented it in 1871 for wrapping bottles and lantern chimneys.","Flute sizes are labeled A, B, C, E and F in the order they were invented, not by how big they are.","Industry and standards bodies avoid the word cardboard because it does not say which product is meant."],"where":[],"whereNote":null,"sources":[{"title":"Corrugated fiberboard","url":"https://en.wikipedia.org/wiki/Corrugated_fiberboard"},{"title":"Cardboard","url":"https://en.wikipedia.org/wiki/Cardboard"},{"title":"Paperboard","url":"https://en.wikipedia.org/wiki/Paperboard"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cardboard-box","name":"Cardboard box","kind":"product","category":"wood-paper","title":"How cardboard boxes are made","url":"https://assemblyline.org/make/cardboard-box","stations":5,"upstream":54,"downstream":42,"depth":9,"dek":"Boxes ship flat. The first pre-cut ones came from a printer's accident when a creasing ruler shifted and cut instead.","answer":"A cardboard box begins as a flat sheet of corrugated board. A printing and cutting line prints the artwork, scores the fold lines, cuts slots to make flaps and glues one edge into a joint. The box ships folded flat to the packer, who sets it up, fills it and closes it with tape.","aka":["corrugated box","shipping box","carton"],"inputs":["cardboard","ink","adhesive"],"uses":["soap","toothpaste","deodorant","detergent","plastic-bag","nitrile-glove","washing-machine","vacuum-cleaner","electric-kettle","paperclip","donut","corn-flakes","popcorn","cotton-candy","rubiks-cube","crayon","fireworks","candle","salsa","canned-meat","fish-sticks","zip-bag","blender","dishwasher","pillow","board-game","jigsaw-puzzle","trading-cards","cotton-swab","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","sticky-notes"],"grounds":["water","timber","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","limestone","coal","natural-gas","sugar-beet"],"upstreamSlugs":["cardboard","ink","adhesive","wood-pulp","water","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","ethylene","propylene","ammonia","methanol","acetone","nitric-acid","hydrogen","rock-salt","limestone","benzene","coal","molasses","naphtha","natural-gas","toluene","sugar-beet"],"downstreamSlugs":["soap","toothpaste","deodorant","detergent","plastic-bag","nitrile-glove","washing-machine","vacuum-cleaner","electric-kettle","paperclip","donut","corn-flakes","popcorn","cotton-candy","rubiks-cube","crayon","fireworks","candle","salsa","canned-meat","fish-sticks","zip-bag","blender","dishwasher","pillow","board-game","jigsaw-puzzle","trading-cards","cotton-swab","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","sticky-notes","syringe"],"steps":[{"name":"Print the artwork","process":"print","text":"Flat sheets of board pass through a press that prints the logo and handling marks directly onto the surface, usually with flexographic plates. Fine flutes give a smoother surface for sharp graphics.","inputs":["cardboard","ink"]},{"name":"Crease the fold lines","process":"stamp","text":"Wheels or a die crush grooves into the board along every line where it will bend. The creases let the box fold cleanly without cracking.","inputs":[]},{"name":"Slot and cut the flaps","process":"cut","text":"Blades cut slots between the creases, which free the flaps that will fold shut. Die cutting can score and slot in one pass.","inputs":[]},{"name":"Glue the joint","process":"assemble","text":"A folder-gluer machine folds the blank over on itself and glues one edge, called the manufacturer's joint. Staples or tape can do the same job.","inputs":["adhesive"]},{"name":"Bundle flat","process":"package","text":"The boxes are knocked down flat, counted into bundles and strapped. Shipping them flat saves enormous space until the packer opens each one.","inputs":[]}],"facts":["Robert Gair invented the pre-cut paperboard box in 1890 after a metal ruler that creased bags shifted during a print run and cut them instead.","The first paperboard carton was produced in England in 1817."],"where":[],"whereNote":null,"sources":[{"title":"Cardboard box","url":"https://en.wikipedia.org/wiki/Cardboard_box"},{"title":"Corrugated fiberboard","url":"https://en.wikipedia.org/wiki/Corrugated_fiberboard"},{"title":"Paperboard","url":"https://en.wikipedia.org/wiki/Paperboard"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"carnauba","name":"Carnauba palm wax","kind":"raw","category":"farm","title":"How carnauba wax is collected","url":"https://assemblyline.org/make/carnauba","stations":3,"upstream":0,"downstream":2,"depth":0,"dek":"The shine on a waxed car and a glossy candy comes from the leaves of a single Brazilian palm.","answer":"Carnauba is the wax that coats the leaves of a palm native to northeastern Brazil. Workers cut and dry the leaves, beat them to knock the wax loose, then refine and bleach it into hard yellow-brown flakes. It melts at a higher temperature than most natural waxes.","aka":["Brazil wax","palm wax","carnauba wax"],"inputs":[],"uses":["jelly-beans","candy-coated-chocolate"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["jelly-beans","candy-coated-chocolate"],"steps":[{"name":"Cut and dry the fronds","process":"harvest","text":"Workers collect leaves from the carnauba palm and lay them out to dry. The wax sits on the leaf surface as a protective coat.","inputs":[]},{"name":"Beat off the wax","process":"crush","text":"Dried leaves are beaten to loosen the powdery wax. What falls off is collected as a crude powder.","inputs":[]},{"name":"Filter and bleach the flakes","process":"wash","text":"The crude wax is melted, filtered, spun in a centrifuge and bleached. Cleaner grades are sold as T1, and lower grades as T3 and T4.","inputs":[],"spec":"melts at 82 to 86 °C"}],"facts":["Carnauba is known as the Queen of Waxes and is among the hardest natural waxes.","It melts at a higher temperature than beeswax, which melts at 62 to 64 °C.","The palm is native to, and grown only in, a handful of northeastern Brazilian states."],"where":[],"whereNote":null,"sources":[{"title":"Carnauba wax","url":"https://en.wikipedia.org/wiki/Carnauba_wax"},{"title":"Copernicia prunifera","url":"https://en.wikipedia.org/wiki/Copernicia_prunifera"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"carpet","name":"Carpet","kind":"product","category":"textiles","title":"How carpet is made","url":"https://assemblyline.org/make/carpet","stations":6,"upstream":31,"downstream":1,"depth":8,"dek":"A tufting machine punches rows of looped yarn into a backing, and that is how most carpet in homes is made.","answer":"Most domestic carpet is tufted. A tufting machine pushes loops of yarn through a fabric backing, and the loops are left as they are or sheared into a cut pile. A second backing is bonded underneath for stability. Nylon and polypropylene make up an estimated 90 percent of the commercial market.","aka":["rug","wall-to-wall carpet","tufted carpet"],"inputs":["nylon","polypropylene","wool-yarn","water","adhesive"],"uses":["car"],"grounds":["water","fleece","air","natural-gas","crude-oil","coal","sulfur","rock-salt"],"upstreamSlugs":["nylon","polypropylene","wool-yarn","water","adhesive","benzene","nitric-acid","ammonia","propylene","fleece","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","naphtha","hydrogen","toluene","air","natural-gas","crude-oil","ethylene","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","coal","sulfur","rock-salt"],"downstreamSlugs":["car"],"steps":[{"name":"Extrude the fiber","process":"extrude","text":"Molten nylon or polypropylene is forced through spinneret holes to make long continuous filaments. Wool, by comparison, has to be sheared, washed and spun.","inputs":["nylon","polypropylene"]},{"name":"Twist and dye the yarn","process":"dye","text":"Filaments are twisted into carpet yarn and dyed. Nylon can be dyed after spinning or colored in its molten state, while polypropylene is hard to dye. Wool is often blended with nylon to improve durability.","inputs":["wool-yarn","water"]},{"name":"Tuft into the backing","process":"weave","text":"A tufting machine drives yarn through a primary backing with rows of needles, leaving loops on the surface. Cutting the loops makes a plush cut pile, and leaving them makes a Berber loop pile.","inputs":[]},{"name":"Bond on a second backing","process":"laminate","text":"A second backing, a woven hessian or a man-made equivalent, is bonded to the first backing with adhesive. It locks the tufts in place and stabilizes the carpet.","inputs":["adhesive"]},{"name":"Shear the pile","process":"cut","text":"Blades trim the pile to an even height. Shearing the loops also gives different textures.","inputs":[]},{"name":"Roll for shipping","process":"package","text":"The carpet is inspected, trimmed at the edges and wound onto rolls.","inputs":[]}],"facts":["The oldest surviving knotted carpet is the Pazyryk carpet, excavated from a frozen tomb in Siberia and dated to the 5th to the 3rd century BC.","The most common wool blend in modern carpet is 80 percent wool to 20 percent synthetic fiber."],"where":[],"whereNote":null,"sources":[{"title":"Carpet","url":"https://en.wikipedia.org/wiki/Carpet"},{"title":"Wool","url":"https://en.wikipedia.org/wiki/Wool"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cast-iron-pan","name":"Cast iron pan","kind":"product","category":"hardware","title":"How cast iron pans are made","url":"https://assemblyline.org/make/cast-iron-pan","stations":6,"upstream":19,"downstream":0,"depth":4,"dek":"A cast iron pan is poured in one piece, handle and all, into a mold made of damp sand.","answer":"Molten iron is poured into a mold packed from sand, forming the pan and handle together in one piece. After it cools, the sand is shaken off, the rough edges are ground away, and the surface is coated with oil that is baked on. The oil layer is what makes a good pan nearly nonstick.","aka":["cast iron skillet","iron frying pan"],"inputs":["pig-iron","steel-scrap","silica-sand","vegetable-oil"],"uses":[],"grounds":["silica-sand","iron-ore","limestone","air","soybeans","rapeseed","water","clay","coal","natural-gas","crude-oil"],"upstreamSlugs":["pig-iron","steel-scrap","silica-sand","vegetable-oil","iron-ore","coke","limestone","air","oxygen","propane","soybeans","rapeseed","hexane","water","clay","coal","natural-gas","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Melt iron in the furnace","process":"melt","text":"Pig iron and scrap steel are charged into a furnace and heated until liquid. The mix sets how much carbon ends up in the casting.","inputs":["pig-iron","steel-scrap"]},{"name":"Pack the sand mold","process":"mold","text":"Damp sand is pressed around a pattern in the shape of the pan, once for the top half and once for the bottom half. The halves are then closed over each other to leave a cavity in the shape of the pan.","inputs":["silica-sand"]},{"name":"Pour the iron","process":"cast","text":"Molten iron runs through channels into the cavity and fills it. The whole pan, handle included, is made as a single piece.","inputs":[]},{"name":"Break out the casting","process":"separate","text":"Once the iron has cooled and set, the mold is broken apart and the sand falls away. The channels that fed the metal are snapped off.","inputs":[]},{"name":"Grind off rough spots","process":"grind","text":"Seams and stubs are ground down. The cooking surface may be machined smoother.","inputs":[]},{"name":"Bake on a coat of oil","process":"coat","text":"A film of fat or oil is applied and baked until it hardens into a dark, slick surface. Repeated seasoning at home builds that layer thicker and protects the iron from rust.","inputs":["vegetable-oil"]}],"facts":["The first mention of a cast-iron kettle in English appeared in 679 or 680.","Griswold began making cast-iron cookware in 1865.","Nonstick aluminum pans pushed cast iron out of favor in the 1960s and 1970s, and most American makers closed."],"where":[],"whereNote":null,"sources":[{"title":"Cast-iron cookware","url":"https://en.wikipedia.org/wiki/Cast-iron_cookware"},{"title":"Sand casting","url":"https://en.wikipedia.org/wiki/Sand_casting"},{"title":"Cast iron","url":"https://en.wikipedia.org/wiki/Cast_iron"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"castor-beans","name":"Castor beans","kind":"raw","category":"farm","title":"How castor beans are grown","url":"https://assemblyline.org/make/castor-beans","stations":3,"upstream":0,"downstream":1,"depth":0,"dek":"Castor seeds are not beans, and they carry one of the most potent plant poisons known.","answer":"Castor beans are the oil-rich seeds of a fast-growing tropical shrub, 40 to 60 percent oil. They grow in spiny capsules that split open when ripe. The seeds are pressed for oil used in lubricants, coatings and nylon, and heating during extraction destroys the poison ricin.","aka":["castor seeds","ricinus communis","castor oil plant"],"inputs":[],"uses":["lipstick"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["lipstick"],"steps":[{"name":"Grow the tropical shrub","process":"grow","text":"Castor is native to the Horn of Africa and now grows across the tropics. It is a quick-growing shrub that can reach the size of a small tree and cannot take frost.","inputs":[]},{"name":"Gather the spiny capsules","process":"harvest","text":"Each fruit is a spiny capsule holding large glossy seeds with brown mottling. Harvesting needs care, because the seeds are poisonous and can trigger allergies in sensitive workers.","inputs":[]},{"name":"Separate seed from capsule","process":"separate","text":"Capsules are dried and hulled and the clean seeds are bagged for the crushing mill. The seeds are 40 to 60 percent oil, so a mill gets a lot out of each bag.","inputs":[]}],"facts":["Castor oil is mostly ricinoleic acid, which makes it a sought-after industrial feedstock that costs more than ordinary seed oils.","Roughly 270,000 to 360,000 tonnes of castor oil are made each year.","In India, Pakistan and Nepal, grains are preserved by coating them in castor oil."],"where":[],"whereNote":null,"sources":[{"title":"Ricinus","url":"https://en.wikipedia.org/wiki/Ricinus"},{"title":"Castor oil","url":"https://en.wikipedia.org/wiki/Castor_oil"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cattle","name":"Cattle","kind":"raw","category":"farm","title":"How cattle are raised","url":"https://assemblyline.org/make/cattle","stations":3,"upstream":0,"downstream":2,"depth":0,"dek":"Beef cattle go to slaughter at about 18 months, while a dairy cow is typically kept for about five years.","answer":"Cattle are bred and raised on pasture and feed for beef, milk and hides. A cow carries her calf for about nine months, and farms often use artificial insemination to pick genetics.","aka":["beef cattle","cattle farming","cattle ranching","cows"],"inputs":[],"uses":["hot-dog","beef-jerky"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["hot-dog","beef-jerky"],"steps":[{"name":"Breed the cows","process":"grow","text":"Gestation takes about nine months. Many farms use artificial insemination, which lets a farmer choose from many bulls. Calves are born roughly 52:48 male to female.","inputs":[]},{"name":"Graze and feed","process":"grow","text":"Cattle graze on pasture, preferring a mix of about 70% clover and 30% grass. Cattle can live naturally for 25 to 30 years.","inputs":[]},{"name":"Send to slaughter","process":"harvest","text":"Beef cattle go for slaughter at about 18 months. Their meat is called beef, and calves' meat is veal. About 300 million cattle, including dairy animals, are slaughtered each year for food.","inputs":[]}],"facts":["There were over 940 million cattle in the world by 2022.","Cattle supply about a quarter of the world's meat, with world cattle meat production at 72.3 million tons in 2021.","Taurine cattle were domesticated about 10,500 years ago from wild aurochs."],"where":[],"whereNote":null,"sources":[{"title":"Cattle","url":"https://en.wikipedia.org/wiki/Cattle"},{"title":"Cattle feeding","url":"https://en.wikipedia.org/wiki/Cattle_feeding"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cattle-hide","name":"Cattle hide","kind":"raw","category":"farm","title":"How cattle hides are recovered","url":"https://assemblyline.org/make/cattle-hide","stations":5,"upstream":0,"downstream":30,"depth":0,"dek":"Brine can cure a cowhide in about 24 hours, a job that once took 30 days in salted piles.","answer":"Cattle hide comes off the carcass at slaughter as a by-product of beef, and it starts to decompose within hours. Packers wash it in chilled water, flesh off fat and manure, and soak it for about a day in a paddle-stirred raceway of saturated brine. Then it is wrung, graded, bundled and shipped to a tanner.","aka":["cowhide","raw hides","rawhide","bovine hide","animal hides"],"inputs":[],"uses":["gelatin","sausage-casing","leather"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["gelatin","sausage-casing","leather","yogurt","gummy-bears","marshmallow","wine","gelatin-dessert","gelatin-capsule","banknote","hot-dog","sausage","salami","wristwatch","baseball","basketball","ice-skates","tennis-racket","football","saxophone","winter-gloves","leather-belt","handbag","wallet","hiking-boots","high-heels","digital-camera","leather-shoe","champagne","frozen-pizza"],"steps":[{"name":"Pull the skin at slaughter","process":"harvest","text":"Cattle are rarely kept for their skins alone, so this crop arrives as a by-product of beef. Bacteria and enzymes start work within a few hours of the animal's death, and that sets the pace for everything after.","inputs":[]},{"name":"Wash in chilled water","process":"wash","text":"Skins tumble through a rotary screen under jets of chilled water. Much of the manure and blood rinses away, and the cold hardens the fat, which makes the next machine's job easier.","inputs":[]},{"name":"Flesh off fat and manure","process":"cut","text":"A heavy machine scrapes manure off the outer face and fat and flesh off the inner face in one pass. Brands and scores then show clearly for grading, and tanners stop paying freight on material of little use in leather. Some plants cure first and flesh afterward.","inputs":[]},{"name":"Cure in a brine raceway","process":"dry","text":"The usual tank is an oval vat with an island in the middle, about 8 feet wide and 5 feet deep. Two paddles keep skins circling in saturated brine, which pulls out water and stops bacteria. A popular 15,000-gallon tank holds about 550 at a time.","inputs":[],"spec":"about 24 hours in brine"},{"name":"Wring and bundle","process":"package","text":"A wringing machine squeezes out brine as each skin leaves the tank, or it drains over a rack for 24 to 48 hours. Bundles are stored by grade until there is a carload. With a wringer, a cured bundle can be ready to ship the day after slaughter.","inputs":[]}],"facts":["Cattle hides account for about 65% of world leather production.","Rawhide is more sensitive to water than leather and softens and stretches quickly if left wet.","Salt crystals alone cannot cure a skin: they first have to dissolve in water, which is why even dry-salted piles rely on the skin's own moisture to make brine."],"where":[{"place":"India","share":"largest producer of cattle hides"}],"whereNote":"2012, ranking by cattle hide production.","sources":[{"title":"Rawhide (material)","url":"https://en.wikipedia.org/wiki/Rawhide_(material)"},{"title":"Cattle","url":"https://en.wikipedia.org/wiki/Cattle"},{"title":"Process, Union Hide Company","url":"https://unionhide.com/process.php"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"caustic-soda","name":"Caustic soda","kind":"material","category":"chemicals","title":"How caustic soda is made","url":"https://assemblyline.org/make/caustic-soda","stations":5,"upstream":2,"downstream":291,"depth":1,"dek":"Caustic soda is a leftover that a chlorine plant must sell, because it cannot make one without the other.","answer":"Caustic soda is made at the same time as chlorine, by passing electric current through salt brine in a membrane cell. Sodium ions cross the membrane and combine with hydroxide to form a weak sodium hydroxide solution. Evaporators boil off water until the liquid is strong enough to sell, and a plant can also flake or pearl it as a solid.","aka":["sodium hydroxide","lye","NaOH"],"inputs":["rock-salt","water"],"uses":["soap","shampoo","aspirin","detergent","bleach","polycarbonate","epoxy","glycerin","alumina","pretzel","gallium","superabsorbent-polymer","kitchen-sponge","polyvinyl-alcohol","wood-pulp","rayon"],"grounds":["rock-salt","water"],"upstreamSlugs":["rock-salt","water"],"downstreamSlugs":["soap","shampoo","aspirin","detergent","bleach","polycarbonate","epoxy","glycerin","alumina","pretzel","gallium","superabsorbent-polymer","kitchen-sponge","polyvinyl-alcohol","wood-pulp","rayon","led-bulb","drone","eyeglass-lens","sunglasses","bike-helmet","blender","suitcase","smartwatch","wireless-earbuds","phone-charger","digital-camera","camera-lens","compact-disc","game-console","thermometer","adhesive","printed-circuit-board","wind-turbine","electric-motor","rebar","aluminum-can","airplane","surfboard","ski","snowboard","tennis-racket","fishing-rod","prosthetic-leg","loudspeaker","umbrella","toothpaste","sunscreen","chewing-gum","snow-globe","cough-syrup","gelatin-capsule","aluminum","smartphone-glass","laminate-floor","spark-plug","led","sanitary-pad","diaper","pvb","banknote","nail-polish","cellulose-acetate","paper","cardboard","toilet-paper","facial-tissue","tampon","eyeglass-frame","adhesive-bandage","credit-card","duct-tape","ev-battery","pencil","nail","insulation","popcorn","windshield","skateboard","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","wooden-chair","door","pencil-eraser","clear-tape","staple","sofa","ice-skates","golf-club","volleyball","cricket-bat","dartboard","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","globe","pinball-machine","cotton-swab","roof-shingle","double-glazed-window","brake-pad","sailboat","dress-shirt","suit","raincoat","handbag","wallet","flip-flops","hiking-boots","high-heels","microphone","e-reader","plywood","mdf","cardboard-box","book","envelope","sticky-notes","playing-cards","match","sneaker","leather-shoe","baseball-cap","carpet","mattress","hearing-aid","pacemaker","smartphone","laptop","television","hard-drive","solid-state-drive","computer-keyboard","computer-mouse","microwave-oven","washing-machine","satellite","car","electric-car","airbag","rocket","locomotive","motorcycle","elevator","ceiling-fan","treadmill","smoke-detector","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","refrigerator","vacuum-cleaner","dishwasher","air-conditioner","subway-train","concrete","skyscraper","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","lipstick","microchip","oled-screen","lithium-ion-cell","solar-cell","solar-panel","aluminum-foil","brass","cobalt","chromium","nonstick-pan","mirror","car-engine","bicycle","pressure-cooker","toaster","office-chair","yo-yo","toy-car","eyeshadow","asthma-inhaler","wheelchair","ladder","aluminum-window-frame","vinyl-record","vanadium","newspaper","zipper","n95-mask","lcd-screen","dice","shoelace","aa-battery","drywall","crayon","fireworks","plastic-straw","paper-cup","egg-carton","wallpaper","toothbrush","plastic-wrap","trading-cards","cake-mix","hair-dye","shipping-container","plastic-bag","nitrile-glove","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","candle","salsa","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","wheelbarrow","light-switch","usb-cable","condom","wristwatch","faucet","padlock","tire","electric-guitar","trumpet","ballpoint-pen","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","power-outlet","leather-belt","flag","hip-implant","turbine-blade","tungsten-carbide","stent","stainless-steel","safety-pin","razor-blade","dumbbell","wrench","nichrome","leather","down-jacket","backpack","jeans","candy-cane","syringe","jet-engine","saw-blade","kitchen-knife","fork","thermos","water-bottle","football","winter-gloves"],"steps":[{"name":"Make and purify brine","process":"mix","text":"Salt is dissolved in water and the brine is treated to remove calcium, magnesium and other contaminants. Impurities would clog and ruin the cell membrane.","inputs":["rock-salt","water"]},{"name":"Electrolyze it in membrane cells","process":"electrolyze","text":"Current splits the brine. Chlorine bubbles off at one electrode and hydrogen at the other, while sodium ions slip through the membrane into the cathode chamber and pair with hydroxide ions to form caustic soda.","inputs":[]},{"name":"Draw off the weak lye","process":"separate","text":"The caustic liquor leaving the cells is a weak solution. Some is recirculated through the cell and the rest moves on to be concentrated.","inputs":[]},{"name":"Evaporate it stronger","process":"refine","text":"Evaporators boil water off the liquor until it reaches the standard 50% strength. This step uses a lot of steam, which is why cell design aims for the strongest liquor possible to start with.","inputs":[]},{"name":"Ship as liquid, flake or pearls","process":"fill","text":"Most caustic soda leaves the plant as a 50% liquid in tanker trucks and rail cars. Some is dried to solid flakes or pearls and bagged.","inputs":[]}],"facts":["The chloralkali process makes two moles of sodium hydroxide for every mole of chlorine, so the two products have to find buyers in the same ratio.","Caustic soda is used to make wood pulp and paper, textiles, soap and detergents, and drain cleaner."],"where":[],"whereNote":null,"sources":[{"title":"Sodium hydroxide","url":"https://en.wikipedia.org/wiki/Sodium_hydroxide"},{"title":"Chloralkali process","url":"https://en.wikipedia.org/wiki/Chloralkali_process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ceiling-fan","name":"Ceiling fan","kind":"product","category":"machines","title":"How ceiling fans are made","url":"https://assemblyline.org/make/ceiling-fan","stations":8,"upstream":92,"downstream":0,"depth":10,"dek":"Ceiling fans began around 500 BC in India, as big palmyra-leaf blades pulled back and forth by hand.","answer":"A punch machine cuts thin silicon steel laminations, which are stacked and riveted into the stator of a conventional fan motor. Copper wire is wound around that core. The motor goes into a die-cast or stamped-steel housing, blades of wood, metal or plastic go on arms, and the finished fan passes a quality inspection.","aka":["overhead fan","ceiling fans"],"inputs":["sheet-steel","copper-wire","aluminum","printed-circuit-board","plywood","paint"],"uses":[],"grounds":["crude-oil","coal","timber","water","zinc-ore","air","copper-ore","bauxite","silica-sand","limestone","titanium-ore","iron-ore","sulfur","dolomite","manganese-ore","natural-gas","rock-salt","trona","tin-ore","lead-ore","silver-ore","quartz","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["sheet-steel","copper-wire","aluminum","printed-circuit-board","plywood","paint","steel","zinc","copper","crude-oil","coal","petroleum-coke","alumina","fiberglass","epoxy","photoresist","solder","timber","adhesive","water","titanium-dioxide","pigment","acrylic","tin-can","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","copper-ore","bauxite","caustic-soda","silica-sand","limestone","soda-ash","phenol","propylene","acetone","chlorine","phenolic-resin","tin","lead","silver","polyethylene","polyurethane","paraffin-wax","titanium-ore","coke","iron-ore","carbon-black","sulfur","ammonia","methanol","tinplate","lacquer","ink","dolomite","silicon","propane","manganese-ore","natural-gas","rock-salt","carbon-dioxide","trona","benzene","naphtha","formaldehyde","tin-ore","lead-ore","silver-ore","ethylene","nitric-acid","hydrogen","ethanol","vegetable-oil","quartz","charcoal","corn","yeast","toluene","sugarcane","soybeans","rapeseed","hexane","clay","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Punch the laminations","process":"stamp","text":"A punch machine cuts silicon steel into laminations for the stationary core of a conventional AC fan motor.","inputs":["sheet-steel"],"spec":"0.5 to 1.0 mm thick"},{"name":"Stack and rivet the core","process":"assemble","text":"The laminations are stacked, and rivets hold the pile together as the stator. One patent warns that these two steps can add small inaccuracies to the finished dimensions.","inputs":[]},{"name":"Wind the copper coils","process":"assemble","text":"Copper rod is drawn into thin wire and wound around the core to form motor coils. One Chinese machine builder sells a programmable stator winder that lays up to 40 coils at once.","inputs":["copper-wire"]},{"name":"Make the housing","process":"cast","text":"The motor housing is either die cast from aluminum or zinc, or stamped from sheet steel.","inputs":["aluminum"]},{"name":"Wire the circuit board","process":"assemble","text":"On some designs, magnets are mounted over the core and the motor coils are connected to a circuit board.","inputs":["printed-circuit-board"]},{"name":"Shape the blades","process":"cut","text":"Blades are made from wood, plastic or metal, picked for quality and cost and for what buyers will accept, then finished.","inputs":["plywood","paint"]},{"name":"Mount blades on arms","process":"assemble","text":"Each blade is fixed to a metal arm, which bolts to the rotating part of the motor. Lights and other decorative parts go on at this stage.","inputs":[]},{"name":"Inspect the finished fan","process":"inspect","text":"Quality inspections on the manufactured fan weed out defects before it ships.","inputs":[]}],"facts":["Philip Diehl invented the electrically powered ceiling fan in 1882, by adapting the motor he had engineered for the first electric Singer sewing machines.","A die-cast housing adds weight, which steadies a fan and deadens motor noise, while a stamped steel housing costs less and wobbles more."],"where":[],"whereNote":null,"sources":[{"title":"Ceiling fan","url":"https://en.wikipedia.org/wiki/Ceiling_fan"},{"title":"Ceiling Fan Quality: Parts Make a Difference","url":"https://www.lampsplus.com/ideas-and-advice/?p=1266"},{"title":"Ceiling Fan Manufacturing Plant Project Report (Expert Market Research)","url":"https://www.expertmarketresearch.com/reports/ceiling-fan-manufacturing-plant-project-report"},{"title":"Integrated stator and rotor for a DC brushless ceiling fan motor","url":"https://patents.google.com/patent/US7615898"},{"title":"Stator winding machine (GREWIN)","url":"https://www.coilwindingmachinechina.com/stator-winding-machine/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cello","name":"Cello","kind":"product","category":"play","title":"How cellos are made","url":"https://assemblyline.org/make/cello","stations":10,"upstream":47,"downstream":0,"depth":8,"dek":"A good cello takes 200 to 300 hours of hand work, plus weeks of waiting for glue and varnish to dry.","answer":"A cello is built over an internal mold. Ribs are heated and bent, then glued to corner blocks. A maple back and a spruce top are carved from thick slabs with gouges and planes. The top gets a bass bar, edges get purfling, a neck and scroll are carved from maple, and many coats of varnish finish it.","aka":["violoncello","'cello"],"inputs":["lumber","adhesive","steel-wire"],"uses":[],"grounds":["timber","water","crude-oil","natural-gas","air","sulfur","rock-salt","iron-ore","limestone","dolomite","manganese-ore","coal","quartz"],"upstreamSlugs":["lumber","adhesive","steel-wire","timber","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","steel","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","naphtha","natural-gas","air","sulfur","benzene","rock-salt","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","toluene","coal","quartz","charcoal"],"downstreamSlugs":[],"steps":[{"name":"Build the mold","process":"machine","text":"A mold made to the exact inside measurements of the cello shapes and holds the body while it is glued. Templates for the back and top plates are made at the same time.","inputs":[]},{"name":"Bend the ribs","process":"mold","text":"Six ribs are cut and bent with a heating iron and a bending strap, which softens the wood just enough to bend without cracking. They are glued to the corner and end blocks and clamped to the mold.","inputs":["lumber","adhesive"]},{"name":"Carve the plates","process":"machine","text":"Back and top plates start about 25 millimeters thick and are hand-carved with gouges and planes into arches. The arch matters for both strength and sound. Spruce is easier and quicker to shape than harder maple.","inputs":["lumber"]},{"name":"Close the back","process":"assemble","text":"The back plate is glued to the ribs and clamped. The f-holes are drawn on the top and cut out.","inputs":["adhesive"]},{"name":"Glue the bass bar and top","process":"assemble","text":"A bass bar is cut to fit under the top and glued in. Together with the sound post it supports string tension of roughly 80 pounds and carries vibration to the surface. The top is then glued on.","inputs":["adhesive"]},{"name":"Inlay the purfling","process":"machine","text":"A channel is cut around the edges of the top and back and filled with purfling, a decorative inlay that also helps stop cracks from spreading.","inputs":[]},{"name":"Carve the neck and scroll","process":"machine","text":"The neck, pegbox and scroll are roughly cut from one block of maple and hand-carved with planes, chisels and scrapers, then fitted to the body.","inputs":["lumber"]},{"name":"Sun-darken and varnish","process":"coat","text":"The bare cello sits in sunlight or a light box for a week or more, and is exposed to ammonia fumes to darken the wood further. Then comes several coats of the luthier's own varnish, with light sanding between them.","inputs":[]},{"name":"Fit the fingerboard and post","process":"assemble","text":"The fingerboard is attached with weak hide glue so that it can be removed for repairs. A spruce sound post is cut to match the arching and set between the top and back.","inputs":["adhesive"]},{"name":"String it","process":"assemble","text":"The nut, bridge and strings go on, and the nut's string grooves must be cut at precise spacing and angles for the cello to play in tune.","inputs":["steel-wire"]}],"facts":["The varnish on a cello neck is left off on purpose, so a player's thumb doesn't wear it unevenly.","Some cellos are made from aluminum or carbon fiber instead of wood.","The back plate is usually made from two blocks of wood, carefully matched so that the flame and grain align."],"where":[],"whereNote":null,"sources":[{"title":"How a Cello is Made","url":"https://www.simplyforstrings.com.au/blogs/news/how-a-cello-is-made"},{"title":"What Cellos Are Made Of","url":"https://www.johnsonstring.com/cellos-facts/CelloConstruction.htm"},{"title":"Cello","url":"https://en.wikipedia.org/wiki/Cello"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cellulose-acetate","name":"Cellulose acetate","kind":"material","category":"plastics","title":"How cellulose acetate is made","url":"https://assemblyline.org/make/cellulose-acetate","stations":6,"upstream":23,"downstream":4,"depth":6,"dek":"LEGO bricks were made of this wood-based plastic until 1963. Your eyeglass frames may still be.","answer":"Purified wood pulp or cotton is reacted with acetic acid and acetic anhydride, turning a fiber that will not melt into a plastic that will dissolve. A controlled partial reversal then gives the acetone-soluble form. From there it is spun into fiber for cigarette filters and playing cards, or mixed with plasticizer for sheets and molded parts.","aka":["acetate","cellulose diacetate","acetate fiber","safety film"],"inputs":["wood-pulp","acetic-anhydride","water","acetone","plasticizer"],"uses":["sunglasses","dice","shoelace","eyeglass-frame"],"grounds":["water","timber","air","rock-salt","limestone","natural-gas","crude-oil","coal"],"upstreamSlugs":["wood-pulp","acetic-anhydride","water","acetone","plasticizer","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","methanol","carbon-monoxide","benzene","propylene","air","naphtha","rock-salt","limestone","hydrogen","natural-gas","toluene","crude-oil","coal"],"downstreamSlugs":["sunglasses","dice","shoelace","eyeglass-frame"],"steps":[{"name":"Fluff the purified pulp","process":"crush","text":"Special dissolving pulp, or the short linters on cotton seeds, is broken down into a purified fluffy white cellulose. Ordinary pulp reacts unevenly and spoils the product.","inputs":["wood-pulp"]},{"name":"Acetylate the cellulose","process":"react","text":"Cellulose goes into acetic acid and then acetic anhydride, with sulfuric acid as a catalyst. Each repeating unit has three hydroxyl groups, and the reaction turns these into acetate groups.","inputs":["acetic-anhydride"]},{"name":"Partly undo the reaction","process":"react","text":"Controlled hydrolysis takes off the sulfate and some of the acetate. The common form ends up with an acetate on about two of every three hydroxyls. George Miles found around 1903 that this makes it soluble in cheap solvents.","inputs":["water"]},{"name":"Dry into flakes","process":"dry","text":"The material is recovered and dried as flake. In this form it can be stored and shipped, and later turned into fiber, film or molding powder.","inputs":[]},{"name":"Dissolve and spin fiber","process":"spin","text":"Flakes dissolve in acetone to make a thick solution that is pushed through spinnerets. Warm air evaporates the solvent and leaves fine filaments, the same dry-spinning idea used for spandex.","inputs":["acetone"]},{"name":"Or plasticize for sheet","process":"mix","text":"For eyeglass frames and molded parts, flake is mixed with plasticizers into a moldable powder or cast into film. It melts at 230 °C, lower than the fully acetylated form.","inputs":["plasticizer"]}],"facts":["Old acetate film breaks down and releases acetic acid, a decay that archivists call vinegar syndrome.","Camille and Henri Dreyfus did their early research on cellulose acetate from 1904 in a shed in their father's garden in Basel.","During the First World War, acetate dope was used to coat the fabric on airplane wings."],"where":[],"whereNote":null,"sources":[{"title":"Cellulose acetate","url":"https://en.wikipedia.org/wiki/Cellulose_acetate"},{"title":"Cellulose acetate (Britannica)","url":"https://www.britannica.com/technology/cellulose-acetate"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cement","name":"Cement","kind":"material","category":"minerals","title":"How cement is made","url":"https://assemblyline.org/make/cement","stations":7,"upstream":3,"downstream":3,"depth":1,"dek":"Making cement gives off nearly its own weight in carbon dioxide, partly because limestone itself releases CO2 when baked.","answer":"Portland cement is made by grinding limestone and clay, heating the mix to about 1,450 °C in a long rotating kiln until it fuses into marble-sized lumps called clinker, then grinding the clinker with a few percent gypsum. The gypsum controls how fast the powder sets once water is added.","aka":["Portland cement","hydraulic cement"],"inputs":["limestone","clay","gypsum"],"uses":["washing-machine","concrete"],"grounds":["limestone","clay","gypsum"],"upstreamSlugs":["limestone","clay","gypsum"],"downstreamSlugs":["washing-machine","concrete","skyscraper"],"steps":[{"name":"Dig limestone and clay","process":"mine","text":"Limestone is the main ingredient. It is usually impure, with clay mixed in as a source of aluminum and silicon. Shale, sand, iron ore and bauxite can fill in what the local rock lacks.","inputs":["limestone","clay"]},{"name":"Grind and blend the mix","process":"crush","text":"The rock is ground to a fine powder and blended to a precise chemical recipe. Hot exhaust from the kiln is typically used to dry the raw materials in the mill.","inputs":[]},{"name":"Preheat in the cyclone tower","process":"react","text":"The powder falls through a stack of cyclones, where rising kiln gas heats it. Limestone begins to break down into lime and carbon dioxide above 600 °C. Between 1 and 6 cyclone stages are used.","inputs":[]},{"name":"Burn it in the rotary kiln","process":"fire","text":"A steel tube lined with firebrick slopes 1–4° and turns between 30 and 250 times an hour. Feed creeps downhill into a flame fired by coal, oil or gas. At about 1,450 °C the material partly melts and gathers into nodules 1–10 mm across, called clinker.","inputs":[],"spec":"about 1,450 °C"},{"name":"Cool the clinker","process":"chill","text":"The hot clinker drops into a cooler, where air blows through it. That air comes out hot and returns to the kiln as combustion air.","inputs":[]},{"name":"Grind it with gypsum","process":"grind","text":"Between 2 and 8% gypsum, typically 5%, is ground in with the clinker in a cement mill. Without gypsum the powder would set almost instantly when wetted. Typically 15% of the finished powder is finer than 5 μm.","inputs":["gypsum"],"spec":"typically 5% gypsum"},{"name":"Store and ship","process":"package","text":"The finished powder is pumped to silos and shipped in bags or in bulk by truck, rail or ship.","inputs":[]}],"facts":["More than 95% of the world's cement comes from rotary kilns.","Joseph Aspdin named it Portland cement in his 1824 patent because the hardened material resembled Portland stone.","Making a tonne of Portland cement releases nearly a tonne of carbon dioxide."],"where":[{"place":"China","share":"1,700 million tonnes"},{"place":"India","share":"470 million tonnes"},{"place":"Vietnam","share":"100 million tonnes"}],"whereNote":"2025 production, in a world total of 3,800 million tonnes.","sources":[{"title":"Cement","url":"https://en.wikipedia.org/wiki/Cement"},{"title":"Portland cement","url":"https://en.wikipedia.org/wiki/Portland_cement"},{"title":"Cement kiln","url":"https://en.wikipedia.org/wiki/Cement_kiln"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ceramic","name":"Ceramic","kind":"material","category":"minerals","title":"How ceramics are made","url":"https://assemblyline.org/make/ceramic","stations":6,"upstream":4,"downstream":5,"depth":1,"dek":"Firing runs from 600 °C to 1,400 °C, and the heat decides whether clay stays porous or turns glassy.","answer":"A ceramic is a shaped mineral body, usually clay, that is hardened by firing. Makers blend clay, silica and feldspar into a body, form it by hand, press or mold, dry it, and fire it once. Glazed ware gets a coat of glass-forming powder and a second firing that melts it into a smooth skin.","aka":["pottery","earthenware","stoneware"],"inputs":["clay","kaolin","feldspar","quartz"],"uses":["hip-implant","faucet","turbine-blade"],"grounds":["clay","kaolin","feldspar","quartz"],"upstreamSlugs":["clay","kaolin","feldspar","quartz"],"downstreamSlugs":["hip-implant","faucet","turbine-blade","jet-engine","airplane"],"steps":[{"name":"Blend the clay body","process":"mix","text":"A body is a recipe of clays, kaolin, feldspar and quartz, and the recipe sets how hot the ware can be fired. Prepared bodies are by far the dominant type used in industry.","inputs":["clay","kaolin","feldspar","quartz"]},{"name":"Form the shape","process":"mold","text":"Potters throw clay on a wheel. Factories press damp granulated powder in a mold, shape the plastic clay against a spinning plaster mold, or pour liquid clay into a plaster mold.","inputs":[]},{"name":"Dry to bone-dry","process":"dry","text":"At the leather-hard stage the clay holds about 15% moisture and can still be trimmed. Bone-dry clay has almost no moisture left and is extremely brittle, so it is ready for the kiln.","inputs":[]},{"name":"Fire the first time","process":"fire","text":"The bisque firing changes the minerals in the clay permanently. As a rough guide, earthenware is fired at 1,000–1,200 °C, stoneware at 1,100–1,300 °C and porcelain at 1,200–1,400 °C.","inputs":[],"spec":"600–1,400 °C across all types"},{"name":"Glaze the ware","process":"coat","text":"A glaze is a coating that melts into glass. It is applied to the biscuit ware by dipping or spraying. Glaze lowers porosity and gives a smooth, colored surface.","inputs":[]},{"name":"Fire again to melt the glaze","process":"fire","text":"The glost firing melts the glaze so it bonds to the body. Depending on the temperature schedule, it may also mature the body further.","inputs":[]}],"facts":["People have been making ceramics for at least 26,000 years, and the earliest known pieces found so far were sculpted figures, not dishes.","In the 1960s, General Electric scientists found that aluminum oxide could be made translucent under the right manufacturing conditions.","The word ceramic comes from the Ancient Greek keramikos, meaning of or for pottery."],"where":[],"whereNote":null,"sources":[{"title":"Ceramic","url":"https://en.wikipedia.org/wiki/Ceramic"},{"title":"Pottery","url":"https://en.wikipedia.org/wiki/Pottery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"floor-tile","name":"Ceramic floor tile","kind":"product","category":"minerals","title":"How ceramic floor tiles are made","url":"https://assemblyline.org/make/floor-tile","stations":6,"upstream":47,"downstream":0,"depth":8,"dek":"A ceramic tile can ride through a 125-meter kiln and come out fired in as little as 50 minutes.","answer":"About half of a ceramic tile is clay, with feldspar and other minerals making up the rest. The mix is wetted, dried back to a powder, and pressed hard into shape. Pressed tiles are dried, coated with glaze made from ground glass and color, and fired on rollers through a long kiln.","aka":["ceramic tile","porcelain tile"],"inputs":["clay","feldspar","silica-sand","water","glass","ink"],"uses":[],"grounds":["clay","feldspar","silica-sand","water","limestone","rock-salt","trona","soybeans","rapeseed","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","natural-gas","coal","sugar-beet"],"upstreamSlugs":["clay","feldspar","silica-sand","water","glass","ink","soda-ash","limestone","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","rock-salt","ammonia","carbon-dioxide","lime","trona","soybeans","rapeseed","hexane","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","ethylene","natural-gas","hydrogen","benzene","propylene","methanol","coal","molasses","naphtha","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Blend the body mix","process":"mix","text":"Clay is milled with other minerals and water into a slurry, then pumped into a large dryer that turns it into a fine powder. The recipe decides how the tile will shrink, how hard it will be and what color it fires to.","inputs":["clay","feldspar","silica-sand","water"]},{"name":"Press the tile flat","process":"press","text":"Powder drops into molds and is compacted under enormous pressure into a green tile of even thickness.","inputs":[],"spec":"around 5,000 psi"},{"name":"Dry the pressed tile","process":"dry","text":"Warm air drives off the remaining moisture. Pressed tile needs only about half an hour.","inputs":[],"spec":"about 250 F"},{"name":"Glaze and decorate","process":"coat","text":"A curtain of primer falls across each tile, then a glaze of frit, which is made from glass, and color goes on by spray or waterfall. Inkjet printers can lay a pattern over it.","inputs":["glass","ink"]},{"name":"Fire in the kiln","process":"fire","text":"Tiles roll through a long kiln that climbs gradually to full heat. The body hardens and fuses, and the glaze melts and bonds to the surface.","inputs":[],"spec":"around 2,000 F"},{"name":"Sort for flatness","process":"inspect","text":"Finished tiles are checked for size, flatness and surface faults, sorted into grades and boxed.","inputs":[]}],"facts":["The earliest known glazed bricks were found in the Elamite temple at Chogha Zanbil and date to the 13th century BCE.","A machine can glaze about 2,000 square feet of tile a day, while a hand worker manages about 50 pieces.","Recycled material can make up as much as 70 percent of a ceramic tile."],"where":[],"whereNote":null,"sources":[{"title":"Tile","url":"https://en.wikipedia.org/wiki/Tile"},{"title":"Stoneware","url":"https://en.wikipedia.org/wiki/Stoneware"},{"title":"How It's Made: Ceramic Tile","url":"https://www.architectmagazine.com/?p=136595"},{"title":"Tile: How It's Made","url":"https://www.levis4floors.com/tile-how-its-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chain-link-fence","name":"Chain-link fence","kind":"product","category":"hardware","title":"How chain-link fence is made","url":"https://assemblyline.org/make/chain-link-fence","stations":8,"upstream":40,"downstream":0,"depth":6,"dek":"Chain-link fence was first woven on machines adapted from cloth looms.","answer":"Galvanized steel wire arrives in coils and passes over cams and straighteners into a weaving machine. A forming worm and a spinning blade curl each wire into a zigzag spiral, and it screws into the edge of the growing mesh to make a diamond pattern. Blades cut the finished picket at fence height and hooks shape its ends. The mesh is stretched flat over rollers, trimmed, and rolled for shipping.","aka":["cyclone fence","wire mesh fence"],"inputs":["steel-wire","zinc","pvc"],"uses":[],"grounds":["zinc-ore","air","water","sulfur","natural-gas","rock-salt","iron-ore","limestone","dolomite","manganese-ore","crude-oil","titanium-ore","coal","quartz","timber"],"upstreamSlugs":["steel-wire","zinc","pvc","steel","zinc-ore","air","sulfuric-acid","ethylene","chlorine","water","pigment","plasticizer","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","sulfur","naphtha","natural-gas","rock-salt","iron-ore","titanium-dioxide","carbon-black","propylene","coke","limestone","dolomite","silicon","propane","manganese-ore","crude-oil","hydrogen","titanium-ore","coal","quartz","charcoal","timber"],"downstreamSlugs":[],"steps":[{"name":"Draw and galvanize","process":"coat","text":"Steel wire is pulled through dies to size and passed through molten zinc against rust, then wound into large coils for the weaving line.","inputs":["steel-wire","zinc"]},{"name":"Straighten the wire","process":"press","text":"Two wires pay off roll holders, centering over cams and running through devices that kill their tension and correct their shape.","inputs":[]},{"name":"Curl into zigzag","process":"press","text":"Pulled along by the turning weaving blade, the wires pass through a forming worm and an extension worm, which give them their spiral form.","inputs":[]},{"name":"Weave into the mesh","process":"weave","text":"As the blade rotates, each new spiral threads through the last picket in the fabric, and every bend hooks into its neighbor to form the diamond.","inputs":[]},{"name":"Cut and hook the picket","process":"cut","text":"Feeding stops at fence height while blades cut the picket and forming hooks shape its ends. The cycle then starts on the next one.","inputs":[]},{"name":"Stretch and trim","process":"press","text":"Rollers hold the mesh taut and flat to remove slack, and spare wire is trimmed from the edges to prevent snagging.","inputs":[]},{"name":"Coat if colored","process":"coat","text":"Some rolls receive a polyester or vinyl coat over the zinc for color and extra protection.","inputs":["pvc"]},{"name":"Roll the fabric","process":"package","text":"Mesh is rolled into bundles for shipping to the fence site.","inputs":[]}],"facts":["Charles Barnard developed a way to make chain-link fence by machine in 1844, based on cloth weaving machines in Norwich, England.","Tennis courts often use a diamond size of 1.75 inches so power hitters cannot lodge the ball in the fence."],"where":[],"whereNote":null,"sources":[{"title":"CA patent 2070709: Process for the manufacture of chain link fence","url":"https://patents.google.com/patent/CA2070709A1/en"},{"title":"Qunkun Metal: How chain link fence is made","url":"https://www.qunkunmetal.com/news/how-chain-link-fence-is-made.html"},{"title":"Chain-link fencing","url":"https://en.wikipedia.org/wiki/Chain-link_fencing"},{"title":"Hot-dip galvanizing","url":"https://en.wikipedia.org/wiki/Hot-dip_galvanizing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"champagne","name":"Champagne","kind":"product","category":"drink","title":"How champagne is made","url":"https://assemblyline.org/make/champagne","stations":8,"upstream":55,"downstream":0,"depth":7,"dek":"The bubbles are made inside the sealed bottle, and the dead yeast is removed by freezing a plug of ice in the neck.","answer":"Champagne is a sparkling wine from France's Champagne region, made mainly from Pinot noir, Pinot meunier and Chardonnay. A still base wine is bottled with yeast and sugar, which start a second fermentation inside the sealed bottle. The bottles age on their yeast, are turned until it settles in the neck, then frozen and opened to eject it.","aka":["champagne method","méthode champenoise","traditional method","sparkling wine"],"inputs":["grapes","yeast","wine","sugar","glass-bottle","cork-stopper"],"uses":[],"grounds":["grapes","water","sugarcane","sugar-beet","silica-sand","limestone","cork-bark","timber","pigs","cattle-hide","rock-salt","trona","crude-oil","natural-gas","air","corn","quartz","coal","iron-ore","dolomite","manganese-ore","sulfur"],"upstreamSlugs":["grapes","yeast","wine","sugar","glass-bottle","cork-stopper","water","molasses","wine-barrel","gelatin","sugarcane","sugar-beet","lime","silica-sand","soda-ash","limestone","polyethylene","cork-bark","paraffin-wax","silicone","timber","steel","pigs","cattle-hide","rock-salt","ammonia","carbon-dioxide","trona","ethylene","crude-oil","hydrogen","silicon","methanol","hydrochloric-acid","pig-iron","magnesium","steel-scrap","oxygen","manganese","argon","natural-gas","air","corn","naphtha","quartz","coke","coal","charcoal","chlorine","iron-ore","dolomite","propane","manganese-ore","sulfuric-acid","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Press the grapes gently","process":"press","text":"Pinot noir, Pinot meunier and Chardonnay are pressed with very little skin contact. Even the dark grapes give a pale juice, because the pigment sits in the skins.","inputs":["grapes"]},{"name":"Ferment the base wine","process":"ferment","text":"The juice ferments into a still, tart base wine, usually in separate lots by grape and vineyard. These lots are later combined into one cuvée.","inputs":["yeast"]},{"name":"Blend the cuvée","process":"mix","text":"The cellar master tastes the lots and blends them, often including reserve wines from earlier years. This gives the house its consistent style.","inputs":["wine"]},{"name":"Seal in sugar and yeast","process":"fill","text":"The blend is bottled with a measured dose of yeast and sugar and closed with a crown cap, similar to the one on a beer bottle. Each house guards its own recipe.","inputs":["sugar","yeast","glass-bottle"]},{"name":"Ferment again in the bottle","process":"ferment","text":"Yeast eats the added sugar inside the sealed bottle. The carbon dioxide has nowhere to go, so it dissolves into the wine and builds pressure. The dead yeast, called lees, settles along the bottle wall.","inputs":[],"spec":"at least fifteen months of aging"},{"name":"Turn the bottles","process":"separate","text":"Bottles are tilted nose-down and slowly rotated and tapped by hand or by machine. This process, remuage, coaxes the lees into the neck.","inputs":[]},{"name":"Freeze the neck","process":"chill","text":"The bottle necks are dipped in a freezing bath, trapping the lees in a plug of ice. The cap is then removed, and the pressure in the bottle blows the plug out.","inputs":[],"spec":"about six bar (90 psi) of pressure"},{"name":"Top up and cork","process":"fill","text":"A little wine and sugar, called the dosage, replaces what was lost and sets the sweetness. The bottle is quickly corked, and a wire cage holds the cork in place against the pressure.","inputs":["wine","sugar","cork-stopper"]}],"facts":["Vintage champagne has to mature for at least three years before it is released.","In the 18th century, cellars lost 20 to 90% of their bottles to bursting, and workers wore heavy iron masks.","Adolphe Jaquesson invented the wire cage, called the muselet, in 1844 to stop corks blowing out.","Dom Pérignon was originally charged by his superiors with getting rid of the bubbles."],"where":[],"whereNote":null,"sources":[{"title":"Champagne","url":"https://en.wikipedia.org/wiki/Champagne"},{"title":"Winemaking","url":"https://en.wikipedia.org/wiki/Winemaking"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"charcoal","name":"Charcoal","kind":"product","category":"chemicals","title":"How charcoal is made","url":"https://assemblyline.org/make/charcoal","stations":5,"upstream":1,"downstream":195,"depth":1,"dek":"Charcoal burners bury a smoldering pile of logs on purpose, starving it of air so the wood cooks without burning.","answer":"Charcoal is wood heated strongly in minimal oxygen until water and volatile compounds are driven off, leaving mostly carbon. Traditional burners stacked billets in a covered pile, while modern plants use retorts that burn the released gas for heat. Wood yields about a quarter of its weight as charcoal.","aka":["wood charcoal","lump charcoal","char"],"inputs":["timber"],"uses":["silicon","vodka","fireworks","incense"],"grounds":["timber"],"upstreamSlugs":["timber"],"downstreamSlugs":["silicon","vodka","fireworks","incense","silicone","polysilicon","magnesium","trichlorosilane","shampoo","deodorant","syringe","condom","hearing-aid","solar-panel","contact-lens","airbag","cork-stopper","pressure-cooker","blender","foundation-makeup","eyeshadow","prosthetic-leg","double-glazed-window","remote-control","electric-toothbrush","silicon-wafer","steel","titanium","water-heater","toy-car","digital-camera","satellite","car","electric-car","champagne","aluminum-window-frame","microchip","memory-chip","camera-sensor","solar-cell","inkjet-printer","toothbrush","lithium-ion-cell","ev-battery","aa-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","pacemaker","hip-implant","jet-engine","thermometer","credit-card","smartphone","laptop","solid-state-drive","computer-keyboard","computer-mouse","drone","rocket","smartwatch","wireless-earbuds","phone-charger","game-console","wifi-router","e-reader","graphics-card","refrigerator","microwave-oven","washing-machine","air-conditioner","treadmill","safety-pin","ceiling-fan","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","concrete","skyscraper","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sailboat","action-figure","power-outlet","electric-kettle","pencil","mirror","golf-ball","wallpaper","wooden-chair","water-bottle","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","snow-globe","neon-sign","toffee"],"steps":[{"name":"Stack the billets","process":"assemble","text":"Wood billets are piled on end in a cone around a central flue, with air holes at the bottom. The whole pile is covered with turf or moistened earth.","inputs":["timber"]},{"name":"Light it and smother it","process":"bake","text":"The pile is lit gradually and kept starved of air. Only part of the wood burns, and its heat carbonizes the rest.","inputs":[]},{"name":"Tend the slow burn","process":"bake","text":"A collier, as charcoal burners are called, watches the smoke and adjusts the air. The skill is managing the heat so the wood chars without turning to ash.","inputs":[]},{"name":"Cool and rake out","process":"chill","text":"Once the sealed pile cools, the black lumps are raked out.","inputs":[],"spec":"about 25% by weight"},{"name":"Or carbonize in a retort","process":"bake","text":"Modern plants cook wood in closed retorts, and burn the gas it releases to supply the process heat. Yields can reach 35 to 40 percent.","inputs":[]}],"facts":["At its peak, charcoal burning employed hundreds of thousands of people and was a major cause of deforestation in Central Europe.","Retorting also recovers by-products such as wood spirit, pyroligneous acid and wood tar.","Activated charcoal is heated to about 900 °C in an inert gas to create tiny pores."],"where":[],"whereNote":null,"sources":[{"title":"Charcoal","url":"https://en.wikipedia.org/wiki/Charcoal"},{"title":"Biochar","url":"https://en.wikipedia.org/wiki/Biochar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cheddar","name":"Cheddar","kind":"product","category":"food","title":"How cheddar is made","url":"https://assemblyline.org/make/cheddar","stations":9,"upstream":5,"downstream":0,"depth":2,"dek":"Cheddar's dense, flaky body comes from cheddaring, where slabs of curd are stacked, turned and squeezed.","answer":"Cheddar begins with soured milk set by rennet. The curd is cut and heated to push out whey, then the slabs are piled up and turned over and over, which squeezes out more moisture. The curd is milled, salted, pressed into blocks and left to mature for months or years.","aka":["cheddar cheese"],"inputs":["pasteurized-milk","table-salt"],"uses":[],"grounds":["raw-milk","rock-salt","seawater"],"upstreamSlugs":["pasteurized-milk","table-salt","raw-milk","rock-salt","seawater"],"downstreamSlugs":[],"steps":[{"name":"Sour the milk","process":"ferment","text":"Starter bacteria are added to warm milk. They turn milk sugar into lactic acid, which gives the cheese its first tang and prepares the milk for rennet.","inputs":["pasteurized-milk"]},{"name":"Set it with rennet","process":"mix","text":"Rennet, the enzyme complex that separates curds from whey, is stirred in. Vegetarian cheddar uses chymosin made by a mold or yeast. Orange cheddar gets a plant extract such as annatto added at this point to give it color.","inputs":[]},{"name":"Cut the curd","process":"cut","text":"Once the milk has gelled, blades cut it into small cubes so whey can run out of each piece.","inputs":[]},{"name":"Heat the cubes","process":"cook","text":"Hard cheeses like cheddar are warmed after cutting. Heat forces out more whey and shapes the final flavor.","inputs":[]},{"name":"Stack and turn the slabs","process":"knead","text":"The curd is drained into slabs, which are piled up and flipped repeatedly. The weight of the stack squeezes out moisture. This is cheddaring, and it gives cheddar its dense, flaky texture.","inputs":[]},{"name":"Mill and salt","process":"mix","text":"The slabs are cut into small pieces and mixed with salt. Salt preserves the cheese, pulls out more water and firms the texture.","inputs":["table-salt"]},{"name":"Press into blocks","process":"press","text":"The salted curd goes into molds and is pressed. More pressure squeezes out more moisture and fuses the pieces into one solid body.","inputs":[]},{"name":"Vacuum-pack the blocks","process":"package","text":"Block-shaped cheeses are sealed in vacuum bags for storage and shipping, in place of the paper and twine used a century ago.","inputs":[]},{"name":"Mature in the cold","process":"ferment","text":"Sealed blocks sit at a steady temperature while enzymes break down protein and fat into sharp-tasting compounds. Vintage cheddar needs 15 months or more. Bitter peptides build up as it ages, and they are part of what people mean by sharp.","inputs":[],"spec":"15 months or more for vintage"}],"facts":["The village of Cheddar in Somerset has caves whose steady temperature and humidity were once used to mature the cheese, and a little still is.","In 1904 Canada exported 234,000,000 pounds of cheddar, and cheddar was the country's second-largest export after timber.","The sharp flavor of aged cheddar is tied to bitter peptides, and the crunchy specks in old cheddar are crystals of calcium lactate."],"where":[],"whereNote":null,"sources":[{"title":"Cheddar cheese","url":"https://en.wikipedia.org/wiki/Cheddar_cheese"},{"title":"Cheese","url":"https://en.wikipedia.org/wiki/Cheese"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cheese","name":"Cheese","kind":"product","category":"food","title":"How cheese is made","url":"https://assemblyline.org/make/cheese","stations":7,"upstream":5,"downstream":0,"depth":2,"dek":"Cheese is milk split into solid curds and liquid whey, then aged until it develops flavor.","answer":"Milk, usually pasteurized, is warmed in a vat and seeded with bacteria that turn lactose into lactic acid. Rennet is added and the milk sets into a gel. The gel is cut, heated and drained of whey, then the curd is salted, pressed into molds and ripened for weeks to years.","aka":["cheddar","cheesemaking","hard cheese"],"inputs":["pasteurized-milk","table-salt"],"uses":[],"grounds":["raw-milk","rock-salt","seawater"],"upstreamSlugs":["pasteurized-milk","table-salt","raw-milk","rock-salt","seawater"],"downstreamSlugs":[],"steps":[{"name":"Warm and seed the milk","process":"ferment","text":"Milk goes into a vat and is brought to a temperature at which starter bacteria thrive. The bacteria eat lactose and make lactic acid, and the starter is chosen for the flavor and texture of the cheese.","inputs":["pasteurized-milk"]},{"name":"Set it with rennet","process":"react","text":"Rennet contains the enzyme chymosin, which snips a protein in the casein micelles. The casein then clumps into a gel, and the milk sets like a soft custard. Many factories use rennet made by fermentation with a fungus.","inputs":[]},{"name":"Cut the curd","process":"cut","text":"Wire knives slice the gel into small cubes. Smaller cubes release more whey, so they make a drier, harder cheese.","inputs":[]},{"name":"Heat and stir out the whey","process":"cook","text":"For cheddar the curd is warmed to about 39 °C. The cubes shrink and squeeze out whey. The whey drains away, and the curd is stacked and turned in slabs, the process called cheddaring.","inputs":[]},{"name":"Salt and mill the curd","process":"mix","text":"Slabs are milled into finger-sized pieces and mixed with salt. Salt draws out more whey and slows spoilage microbes.","inputs":["table-salt"]},{"name":"Press into molds","process":"press","text":"Curd is packed into molds or hoops and pressed so it knits into one solid block or wheel.","inputs":[]},{"name":"Ripen in a cool room","process":"dry","text":"Cheeses rest at controlled temperature and humidity. Hard cheeses age for months or years, while mold-ripened cheeses like Camembert ripen in weeks because surface mold works quickly.","inputs":[]}],"facts":["The first factory for industrial cheese production opened in Switzerland in 1815.","In 2022, world cheese production from whole cow milk was 22.6 million tonnes, with the United States making 28%.","Before the 1860s mass-produced rennet, cheesemakers relied on bacteria from their surroundings or from the previous batch's whey."],"where":[],"whereNote":null,"sources":[{"title":"Cheese","url":"https://en.wikipedia.org/wiki/Cheese"},{"title":"Cheesemaking","url":"https://en.wikipedia.org/wiki/Cheesemaking"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chess-set","name":"Chess set","kind":"product","category":"play","title":"How chess sets are made","url":"https://assemblyline.org/make/chess-set","stations":9,"upstream":41,"downstream":0,"depth":8,"dek":"The horse head on a Staunton knight is carved by hand, and it can account for half the cost of a wooden set.","answer":"A classic wooden chess set is turned on a lathe. Light pieces are cut from boxwood, dark pieces from ebony or rosewood. Each piece spins against a blade that carves its profile, and bases are weighted and covered in felt. The knights' horse heads and the queens' crowns get carving by hand.","aka":["chess pieces","chessmen","staunton chess set"],"inputs":["lumber","adhesive","lacquer","lead"],"uses":[],"grounds":["timber","water","lead-ore","crude-oil","corn","sugarcane","coal","zinc-ore","air","natural-gas","sulfur","rock-salt","sugar-beet"],"upstreamSlugs":["lumber","adhesive","lacquer","lead","timber","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","ethanol","lead-ore","coke","zinc","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","corn","sugarcane","yeast","coal","zinc-ore","air","naphtha","natural-gas","sulfur","benzene","rock-salt","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the turning blanks","process":"cut","text":"Wood is chosen by color and cut to size for each piece. Boxwood is the usual pick for light pieces, and ebony or rosewood for dark ones.","inputs":["lumber"]},{"name":"Turn the shapes","process":"machine","text":"Each blank spins on a lathe while a blade shaves it to profile. The Staunton design suits this: pawns are entirely lathe-turned, and so are the bases of the other pieces.","inputs":[]},{"name":"Carve the knights by hand","process":"machine","text":"Knights are made in two parts, a turned base and a hand-carved horse head on top. The carving can account for half the cost of a wooden set.","inputs":[]},{"name":"Fit the king's cross","process":"assemble","text":"A king's finial is made apart from the body and fits into a hole on top. The queen's crown is the one other part that gets hand carving, with its spurs individually cut.","inputs":["adhesive"]},{"name":"Sand the raw pieces","process":"grind","text":"Pieces go through several rounds of sanding until the surface is smooth enough to take a finish.","inputs":[]},{"name":"Wax or lacquer","process":"coat","text":"Natural waxes give a matte finish, and lacquers a high gloss.","inputs":["lacquer"]},{"name":"Weight the bases","process":"assemble","text":"Metal inserts go into each base for stability and heft. A jolt to the board can slide weighted pieces out of place, but they rarely fall over.","inputs":["lead"]},{"name":"Felt the undersides","process":"assemble","text":"Soft felt, or sometimes leather, covers each base so the pieces do not scratch the board.","inputs":["adhesive"]},{"name":"Check and wrap","process":"package","text":"Pieces are checked for size, smooth finish and even color, then individually wrapped for shipping.","inputs":[]}],"facts":["Staunton pieces are sized by the height of the king, which should sit between 3.35 and 4.13 inches in the pieces used for tournament play.","An expert may spend as long as four days on a set of four knights.","The tapered base molding makes each piece seem to float a few millimeters above the board."],"where":[],"whereNote":null,"sources":[{"title":"The Anatomy of Staunton Chessmen","url":"https://stauntonchesssets.com/staunton_anatomy.html"},{"title":"The Art of Chess Craftsmanship, The English Chess Company","url":"https://www.englishchesscompany.co.uk/blogs/news/the-art-of-chess-craftsmanship-manufacturing-premium-chess-products"},{"title":"Chess set","url":"https://en.wikipedia.org/wiki/Chess_set"},{"title":"How to make a perfectly carved wooden chess set, chessbazaar","url":"https://www.chess.com/blog/chessbazaar/how-to-make-perfectly-carved-wooden-chess-set-at-home"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chewing-gum","name":"Chewing gum","kind":"product","category":"food","title":"How chewing gum is made","url":"https://assemblyline.org/make/chewing-gum","stations":8,"upstream":31,"downstream":0,"depth":7,"dek":"Most chewing gum is chewy plastic: a synthetic polymer base laced with sweetener and flavor.","answer":"Chewing gum starts with a gum base, a mix of elastic polymers, resins, waxes and fillers that is melted and strained. Sweeteners and flavors are kneaded in while the warm mass thickens like dough. It is then extruded, rolled or cut into its final form, and conditioned with powder or coated in layers before it is wrapped.","aka":["gum","bubble gum","chewing gum base"],"inputs":["synthetic-rubber","paraffin-wax","limestone","sugar","corn-syrup","glycerin"],"uses":[],"grounds":["limestone","water","crude-oil","sugarcane","sugar-beet","corn","natural-gas","oil-palm-fruit","soybeans","rapeseed","clay","rock-salt","coal"],"upstreamSlugs":["synthetic-rubber","paraffin-wax","limestone","sugar","corn-syrup","glycerin","naphtha","benzene","ethylene","styrene","water","crude-oil","hydrogen","sugarcane","sugar-beet","lime","corn","corn-starch","palm-oil","vegetable-oil","caustic-soda","methanol","toluene","natural-gas","oil-palm-fruit","soybeans","rapeseed","hexane","clay","rock-salt","coal"],"downstreamSlugs":[],"steps":[{"name":"Melt the gum base","process":"melt","text":"Elastic polymers, resins, waxes and fillers are melted together. Today most of the elastic part is synthetic rubber, since the natural latex once used has largely been replaced by petroleum-derived polymers. Many big gum makers produce their own base in-house, to a secret formula.","inputs":["synthetic-rubber","paraffin-wax","limestone"]},{"name":"Strain out the lumps","process":"separate","text":"The molten base is filtered so no grit or clumps remain. It is then held ready for the next batch.","inputs":[]},{"name":"Knead in sweet and flavor","process":"knead","text":"Sugar or sugar alcohols and flavor oils are worked into the base in a heated mixer. The mix warms and thickens like dough. A normal chewing gum is 20–25% gum base, while sugar-free gum has more.","inputs":["sugar","corn-syrup","glycerin"]},{"name":"Press through a die","process":"extrude","text":"An extruder smooths the dough and pushes it out in a continuous ribbon or rope. Cube and chunk gums are chopped straight off the extruder with a vertical cutter.","inputs":[]},{"name":"Roll into sheets","process":"roll","text":"Stick, slab and tab gums are rolled out in thin sheets between rollers. The sheet thickness sets the weight of each piece.","inputs":[]},{"name":"Score and cut","process":"cut","text":"Knives score the sheet and snap it into sticks or tabs. Pieces are sprinkled with fine powder so they do not stick to one another or to the wrapper.","inputs":[]},{"name":"Coat the pellets","process":"coat","text":"Pellet gum gets its hard shell from layers of syrup applied in temperature-controlled coating pans. Each layer can carry a different flavor, which is why pellet gums can change taste as you bite through.","inputs":["sugar"]},{"name":"Wrap and pack","process":"package","text":"Machines wrap each stick, or seal pellets in bottles and blister packs. Gum sticks to oily surfaces, so lines are kept clear of grease.","inputs":[]}],"facts":["The US FDA allows 46 different chemicals under the umbrella term gum base.","The Aztecs and Maya chewed chicle, a latex from Mesoamerican trees, long before modern gum existed.","By the 1960s, most chewing gum companies had switched from chicle to cheaper polybutadiene."],"where":[],"whereNote":null,"sources":[{"title":"Chewing gum","url":"https://en.wikipedia.org/wiki/Chewing_gum"},{"title":"Gum base","url":"https://en.wikipedia.org/wiki/Gum_base"},{"title":"Chicle","url":"https://en.wikipedia.org/wiki/Chicle"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chicken-nuggets","name":"Chicken nuggets","kind":"product","category":"food","title":"How chicken nuggets are made","url":"https://assemblyline.org/make/chicken-nuggets","stations":7,"upstream":34,"downstream":0,"depth":9,"dek":"A Cornell professor figured out in the 1950s how to make breading stick to ground chicken.","answer":"Chicken is deboned, and the meat is cut or ground and shaped into bite-sized pieces. The pieces pass through a rotating drum that coats them in batter and breading, then through a fryer that sets the coating. They are frozen and packaged, and finished by baking or frying in the home or restaurant.","aka":["nuggets","breaded chicken","chicken bites"],"inputs":["chickens","table-salt","water","flour","corn-starch","vegetable-oil"],"uses":[],"grounds":["chickens","water","rock-salt","seawater","wheat","corn","soybeans","rapeseed","clay","air","crude-oil","natural-gas","sugarcane","sugar-beet","limestone"],"upstreamSlugs":["chickens","table-salt","water","flour","corn-starch","vegetable-oil","rock-salt","seawater","wheat","vitamin-c","corn","soybeans","rapeseed","hexane","clay","hydrogen","air","sugar","plastic-bottle","crude-oil","natural-gas","sugarcane","sugar-beet","lime","pet-plastic","limestone","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","yeast","molasses"],"downstreamSlugs":[],"steps":[{"name":"Debone the chickens","process":"cut","text":"Chicken is deboned by hand or by automatic blades. The softer parts of the carcass can also be forced through a mesh in a grinding step, leaving the harder pieces behind.","inputs":["chickens"]},{"name":"Grind and season","process":"mix","text":"Meat is ground and mixed with salt, water and seasoning until the proteins bind it into a sticky paste. The paste holds together without any skin around it, which was the first problem the meat industry had to solve.","inputs":["table-salt","water"]},{"name":"Shape into nuggets","process":"mold","text":"The paste is pressed into molds or cut into pieces of uniform size. Shapes can be cut into dinosaurs, as Perdue Farms first trademarked in 1991.","inputs":[]},{"name":"Dust and batter","process":"coat","text":"A first coat of flour or starch gives the batter something to grip. A thin outer layer of corn starch also helps the nuggets absorb oil and crisp up in the later stages of frying.","inputs":["flour","corn-starch"]},{"name":"Bread in a drum","process":"coat","text":"The pieces tumble in a large rotating cylinder that evenly coats them in spiced breading. This is where the crumb sticks, which Robert C. Baker worked out at Cornell.","inputs":[]},{"name":"Fry to set the coating","process":"cook","text":"Nuggets are carried through hot oil until the batter sets and the outside reaches the desired color. The inside is only part-cooked or fully cooked, depending on the plant.","inputs":["vegetable-oil"]},{"name":"Freeze and pack","process":"chill","text":"The fried nuggets are frozen, packaged and stored cold for shipping. At home they are baked, or fried again, until they are hot through.","inputs":[]}],"facts":["The chicken nugget was developed in the 1950s by Cornell food science professor Robert C. Baker, and he published it as unpatented academic work.","The largest recorded chicken nugget weighed 51.1 pounds and was unveiled in Secaucus, New Jersey in 2013."],"where":[],"whereNote":null,"sources":[{"title":"Chicken nugget","url":"https://en.wikipedia.org/wiki/Chicken_nugget"},{"title":"Corn starch","url":"https://en.wikipedia.org/wiki/Corn_starch"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chickens","name":"Chickens","kind":"raw","category":"farm","title":"How chickens are raised for meat","url":"https://assemblyline.org/make/chickens","stations":3,"upstream":0,"downstream":3,"depth":0,"dek":"Modern broilers reach slaughter weight in four to six weeks, and the feed they need per kilogram has fallen sharply.","answer":"Meat chickens, called broilers, hatch from eggs after about 21 days of incubation. They are raised in large flocks on feed engineered for fast growth, kept in houses until they reach market weight, and then caught and sent to the processing plant.","aka":["broiler chickens","poultry farming","chicken farming","meat chickens","broilers"],"inputs":[],"uses":["hot-dog","chicken-nuggets","canned-soup"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["hot-dog","chicken-nuggets","canned-soup"],"steps":[{"name":"Hatch the eggs","process":"grow","text":"A fertile chicken egg hatches after about 21 days. The chick breaks out of the shell with an egg tooth and lives off the yolk sac for the first day or so.","inputs":[]},{"name":"Raise broiler flocks","process":"grow","text":"Broilers are bred for fast growth, high feed conversion and low activity. In the US, the average broiler needed 1.91 kilograms of feed for each kilogram of live weight in 2011, down from 4.70 in 1925.","inputs":[]},{"name":"Catch at market weight","process":"harvest","text":"Most commercial broilers reach slaughter weight between four and six weeks of age. Slower-growing breeds take about 14 weeks.","inputs":[]}],"facts":["The global chicken population exceeded 26.5 billion in 2023, with more than 50 billion birds produced annually for consumption.","New Zealand farms have recorded the best broiler feed conversion in the world, at 1.38."],"where":[],"whereNote":null,"sources":[{"title":"Chicken","url":"https://en.wikipedia.org/wiki/Chicken"},{"title":"Broiler","url":"https://en.wikipedia.org/wiki/Broiler"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chili-pepper","name":"Chili pepper","kind":"raw","category":"farm","title":"How chili peppers are grown","url":"https://assemblyline.org/make/chili-pepper","stations":5,"upstream":0,"downstream":3,"depth":0,"dek":"The heat is a defense aimed at mammals. Birds lack the pain receptor, so they eat the fruit and feel nothing.","answer":"Chili plants need warm soil to germinate and a sunny position to fruit, and commercial growers often raise them in polytunnels. Picking green keeps new flowers coming, while leaving fruit on the plant makes it hotter and redder at the cost of a smaller crop. Harvested pods are used fresh or dried for flakes and powder.","aka":["chile","chilli","hot pepper","cayenne"],"inputs":[],"uses":["hot-sauce","salsa","kimchi"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["hot-sauce","salsa","kimchi"],"steps":[{"name":"Germinate in warm soil","process":"grow","text":"Seeds sprout only when warm, close to 21 °C. Growers want a sunny site with moist loam that is not waterlogged, at 21 to 29 °C.","inputs":[]},{"name":"Tend the small plants","process":"grow","text":"Plants stand 20 to 60 centimeters tall and can pollinate themselves. They are sensitive to cold, and at 30 to 38 °C the pollen loses viability, so very hot spells also cost fruit. Stress such as a water shortage can raise the capsaicin in some varieties.","inputs":[]},{"name":"Pick green or red","process":"harvest","text":"Unripe green fruit picked early leaves the plant to make more flowers and more peppers. Fruit left to ripen can grow hotter and change color, at the price of a smaller harvest.","inputs":[]},{"name":"Dry them in the sun","process":"dry","text":"Peppers bound for storage are dried, typically on the ground in hot countries. Smaller lots can be threaded on cotton and hung in a warm, dry place.","inputs":[]},{"name":"Crush flakes and powder","process":"crush","text":"Dried peppers are sold whole or broken down into flakes and chili powder. Heat levels can be measured by liquid chromatography, which reads the concentration of capsaicinoids.","inputs":[]}],"facts":["Chili peppers were cultivated in east-central Mexico some 6,000 to 9,000 years ago.","Washing does not efficiently remove capsaicin from skin.","As of 2023 the hottest recognized cultivar was Pepper X, at over 2.69 million Scoville units."],"where":[{"place":"China","share":"39% of world output"},{"place":"India","share":"12% of world output"}],"whereNote":"2024 world production of green chillies and peppers, 45 million tonnes, as quoted on Wikipedia. The figure covers all Capsicum and Pimenta fruits.","sources":[{"title":"Chili pepper","url":"https://en.wikipedia.org/wiki/Chili_pepper"},{"title":"Chili pepper (Britannica)","url":"https://www.britannica.com/plant/chili-pepper"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chlorine","name":"Chlorine","kind":"material","category":"chemicals","title":"How chlorine is made","url":"https://assemblyline.org/make/chlorine","stations":5,"upstream":5,"downstream":311,"depth":2,"dek":"Table salt dissolved in water and hit with a huge electric current gives off chlorine.","answer":"Chlorine is made by passing electric current through salt brine in a cell split by a membrane. Chlorine gas collects at one electrode. At the other, hydrogen gas and caustic soda form. The chlorine is cooled, dried and compressed into a liquid. Every tonne made brings along a fixed amount of caustic soda.","aka":["Cl2","chloralkali process","chlor-alkali"],"inputs":["rock-salt","water","sulfuric-acid"],"uses":["bleach","pvc","polycarbonate","epoxy","polyurethane","ptfe","kevlar","titanium-dioxide","nitrile-glove","titanium","gold","hydrochloric-acid","refrigerant","spandex","iridium"],"grounds":["rock-salt","water","sulfur","air"],"upstreamSlugs":["rock-salt","water","sulfuric-acid","sulfur","air"],"downstreamSlugs":["bleach","pvc","polycarbonate","epoxy","polyurethane","ptfe","kevlar","titanium-dioxide","nitrile-glove","titanium","gold","hydrochloric-acid","refrigerant","spandex","iridium","kitchen-sponge","credit-card","plastic-wrap","dishwasher","garden-hose","football","volleyball","yoga-mat","action-figure","fashion-doll","globe","inflatable-pool-toy","chain-link-fence","pvc-pipe","vinyl-floor","power-cable","smoke-detector","flip-flops","usb-cable","vinyl-record","led-bulb","drone","eyeglass-lens","sunglasses","bike-helmet","blender","suitcase","smartwatch","wireless-earbuds","phone-charger","digital-camera","camera-lens","compact-disc","game-console","thermometer","adhesive","printed-circuit-board","wind-turbine","electric-motor","rebar","aluminum-can","airplane","surfboard","ski","snowboard","tennis-racket","fishing-rod","prosthetic-leg","loudspeaker","umbrella","adhesive-bandage","pacemaker","refrigerator","car","skateboard","golf-ball","soccer-ball","hardwood-floor","water-heater","sofa","office-chair","roller-skates","bowling-ball","wheelchair","underwear","leggings","swimsuit","raincoat","backpack","sneaker","mattress","razor-blade","nonstick-pan","brake-pad","canoe","toothpaste","sunscreen","lipstick","nail-polish","ink","paint","crayon","pencil-eraser","candy-coated-chocolate","foundation-makeup","e-reader","pigment","hip-implant","jet-engine","drill-bit","microchip","led","needle","gold-ring","fountain-pen","gold-bar","medal","deodorant","silicone","polysilicon","platinum","trichlorosilane","germanium","air-conditioner","asthma-inhaler","aa-battery","popcorn","candy-cane","eyeglass-frame","duct-tape","ev-battery","pencil","nail","insulation","windshield","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","clear-tape","staple","ice-skates","golf-club","cricket-bat","dartboard","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","snow-globe","pinball-machine","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","sailboat","dress-shirt","suit","handbag","wallet","hiking-boots","high-heels","microphone","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","leather-shoe","baseball-cap","carpet","diaper","hearing-aid","smartphone","laptop","television","hard-drive","solid-state-drive","computer-keyboard","computer-mouse","microwave-oven","washing-machine","satellite","electric-car","airbag","rocket","locomotive","motorcycle","elevator","ceiling-fan","treadmill","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","vacuum-cleaner","subway-train","concrete","skyscraper","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","syringe","plastic-bag","tin-can","rubiks-cube","ballpoint-pen","paper-cup","wallpaper","marker-pen","highlighter","frisbee","trading-cards","floor-tile","flag","newspaper","banknote","t-shirt","electric-kettle","scissors","mirror","container-ship","shipping-container","bicycle","water-bottle","billiard-ball","dice","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","leather-belt","toothbrush","mascara","abs-plastic","lego-brick","lcd-screen","porcelain","chalk","sprinkles","plastic-straw","printer-toner","eyeshadow","towel","shampoo","condom","solar-panel","contact-lens","cork-stopper","pressure-cooker","silicon-wafer","optical-fiber","fireworks","cake-mix","hair-dye","tampon","soap","detergent","paperclip","donut","corn-flakes","cotton-candy","candle","salsa","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","cough-syrup","light-switch","facial-tissue","condensed-milk","baby-formula","coconut-milk","canned-soup","padlock","3d-printer-filament","headphones","harmonica","champagne","memory-chip","camera-sensor","solar-cell","toffee"],"steps":[{"name":"Dissolve salt into brine","process":"mix","text":"Salt is dissolved in water to make a saturated brine. Some plants dissolve rock salt underground and pump the brine out to the surface.","inputs":["rock-salt","water"]},{"name":"Purify the brine","process":"wash","text":"Chemicals precipitate calcium, magnesium and other contaminants, and filters and ion-exchange beds take out the rest. Dirty brine ruins the cell membranes.","inputs":[]},{"name":"Run current through the cells","process":"electrolyze","text":"In each membrane cell, chloride ions give up electrons at the anode and become chlorine gas. Only sodium ions can pass through the membrane, and at the cathode water breaks into hydrogen gas and hydroxide.","inputs":[]},{"name":"Cool and dry the chlorine","process":"wash","text":"Hot, wet chlorine leaves the cells and is cooled to remove most of its water. It is then dried by contact with concentrated sulfuric acid.","inputs":["sulfuric-acid"]},{"name":"Compress and liquefy it","process":"chill","text":"The dry gas is compressed and chilled until it condenses. Liquid chlorine is stored in pressure tanks and shipped in tank cars, or piped to plants next door.","inputs":[]}],"facts":["Splitting salt water also gives off hydrogen, one mole of it for every mole of chlorine.","The process uses about 2,500 kWh of electricity for each tonne of caustic soda it makes.","Roughly two-thirds of chlorine ends up in organic chemicals such as PVC, and the finished products often contain no chlorine at all."],"where":[],"whereNote":null,"sources":[{"title":"Chloralkali process","url":"https://en.wikipedia.org/wiki/Chloralkali_process"},{"title":"Chlorine","url":"https://en.wikipedia.org/wiki/Chlorine"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chocolate","name":"Chocolate","kind":"product","category":"food","title":"How chocolate is made","url":"https://assemblyline.org/make/chocolate","stations":8,"upstream":11,"downstream":1,"depth":3,"dek":"Smooth chocolate is ground so fine that the particles drop below what your tongue can detect.","answer":"Chocolate starts as fermented, dried and roasted cocoa beans. The shelled nibs are ground into liquor, then blended with sugar, extra cocoa butter and, for milk chocolate, milk solids. A long churning step called conching makes the mix smooth and mellows its flavor. Careful heating and cooling, called tempering, sets the fat so the bar snaps cleanly.","aka":["chocolate bar","dark chocolate","milk chocolate"],"inputs":["cocoa-beans","sugar","cocoa-butter","powdered-milk","soybeans"],"uses":["candy-coated-chocolate"],"grounds":["cocoa-beans","soybeans","sugarcane","sugar-beet","water","raw-milk","limestone"],"upstreamSlugs":["cocoa-beans","sugar","cocoa-butter","powdered-milk","soybeans","sugarcane","sugar-beet","water","lime","raw-milk","limestone"],"downstreamSlugs":["candy-coated-chocolate"],"steps":[{"name":"Ferment and dry the beans","process":"ferment","text":"Beans and pulp are piled in bins where microbes work for up to seven days. The beans are then dried in the sun to stop mold, before being shipped to the factory.","inputs":["cocoa-beans"],"spec":"up to 7 days"},{"name":"Roast and shell them","process":"bake","text":"The beans are cleaned, roasted and graded. Their shells come off and the pieces of kernel left behind are the nibs.","inputs":[]},{"name":"Mill the nibs to liquor","process":"crush","text":"Grinding melts the fat in the nibs, so dry crumbs become a dark liquid paste called chocolate liquor. About 53% of that liquor is cocoa butter.","inputs":[]},{"name":"Blend the recipe","process":"mix","text":"The liquor is mixed with sugar and extra cocoa butter. Milk chocolate also gets milk solids, and white chocolate replaces all the cocoa solids with milk solids. Refiners then crush the mix finer.","inputs":["sugar","cocoa-butter","powdered-milk"]},{"name":"Churn it for hours","process":"knead","text":"In a conche, heated arms scrape and fling the paste against the walls so every particle is coated in fat. Air carries off sharp acids, and the process runs at about 49 °C for milk chocolate and up to 82 °C for dark. Lecithin from soybeans is added to adjust the flow.","inputs":["soybeans"],"spec":"under 12 hours for a modern multi-tonne batch"},{"name":"Cycle the temperature","process":"heat-treat","text":"Tempering warms and cools the liquid chocolate so the cocoa butter crystallizes in only its most stable form, called Form V. Skipping this step leaves unstable crystals and a dull, crumbly bar that turns white with bloom.","inputs":[]},{"name":"Pour into bar molds","process":"mold","text":"Tempered chocolate is deposited into molds, shaken to remove air bubbles and moved into cooling tunnels. It sets hard enough to be turned out intact.","inputs":[]},{"name":"Wrap and store cool","process":"package","text":"Bars are wrapped to keep out moisture and strong smells, because chocolate absorbs both. Warehouses hold them cool and dry in the dark until they ship.","inputs":[],"spec":"15 to 17 °C"}],"facts":["Rodolphe Lindt invented the conche in Bern in 1879, and conched chocolate was so much smoother that it made mass-produced bars practical.","After conching, cocoa and sugar particles are typically around 20 μm, too small for the tongue to feel.","Ivory Coast and Ghana together contribute about 60% of the world's cocoa supply.","The cacao tree was used as a food source in what is now Ecuador at least 5,300 years ago."],"where":[],"whereNote":null,"sources":[{"title":"Chocolate","url":"https://en.wikipedia.org/wiki/Chocolate"},{"title":"Conching","url":"https://en.wikipedia.org/wiki/Conching"},{"title":"Chocolate liquor","url":"https://en.wikipedia.org/wiki/Chocolate_liquor"},{"title":"Cocoa butter","url":"https://en.wikipedia.org/wiki/Cocoa_butter"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chopsticks","name":"Chopsticks","kind":"product","category":"wood-paper","title":"How chopsticks are made","url":"https://assemblyline.org/make/chopsticks","stations":6,"upstream":22,"downstream":0,"depth":6,"dek":"Disposable chopsticks are made half-split, with the two sticks still joined, so you snap the pair apart at the table.","answer":"Mass-produced chopsticks start as wood, usually aspen, milled into blocks near the forest. A factory cuts blanks from the blocks, sands them and finishes them. Each blank is sized for a whole pair and left half-split, so the two sticks stay joined until a diner pulls them apart. Fine chopsticks are shaped and lacquered by hand.","aka":["disposable chopsticks","wooden chopsticks"],"inputs":["timber","bamboo","lacquer"],"uses":[],"grounds":["timber","bamboo","corn","sugarcane","water","natural-gas","crude-oil","air","sulfur","sugar-beet"],"upstreamSlugs":["timber","bamboo","lacquer","ethanol","acrylic","corn","sugarcane","water","yeast","ethylene","propylene","ammonia","sulfuric-acid","methanol","molasses","naphtha","natural-gas","crude-oil","air","sulfur","sugar-beet","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Mill the wood into blocks","process":"machine","text":"The best-grade wood is chosen and fed through a mill that cuts it into blocks. Aspen is a main wood for disposable pairs. This usually happens near where the trees grew, and the blocks are then shipped to the country that will use them. Bamboo, the other main material, is sawn and split into strips instead.","inputs":["timber","bamboo"]},{"name":"Cut the blanks","process":"cut","text":"At the chopstick factory the blocks are sawn into long thin rectangles. A disposable blank is the width of a whole pair, with a groove along the middle that leaves the halves joined.","inputs":[]},{"name":"Shape the taper","process":"machine","text":"Tools or a sanding belt round the sticks and taper them toward the tip. Some end square and narrow to a cylindrical point, and others are round all the way.","inputs":[]},{"name":"Sand them smooth","process":"grind","text":"Sanding takes off every rough spot, so the stick will not leave splinters in someone's mouth.","inputs":[]},{"name":"Finish with oil or lacquer","process":"coat","text":"Fine chopsticks are dipped in lacquer, which comes from the sap of a sumac tree, and hung to dry until hard and clear. Others are rubbed with oil and buffed, or dipped in nontoxic paint.","inputs":["lacquer"]},{"name":"Bundle for sale","process":"package","text":"Disposable pairs are counted into sleeves and boxes.","inputs":[]}],"facts":["China produces an estimated 45 billion pairs of disposable chopsticks a year, which takes about 25 million fully grown trees.","The English word comes from pidgin: the Chinese kuai-tzu, meaning quick ones, became chop-sticks.","Bamboo disposable chopsticks go through a different line, which splits the bamboo into strips, planes them, treats and dries them, then sharpens and polishes them."],"where":[],"whereNote":null,"sources":[{"title":"Chopsticks","url":"https://encyclopedia.com/manufacturing/news-wires-white-papers-and-books/chopsticks"},{"title":"The production process of disposable chopsticks","url":"https://www.disposablebamboochopsticks.com/news/the-production-process-of-disposable-chopsticks-114201.html"},{"title":"Chopsticks","url":"https://en.wikipedia.org/wiki/Chopsticks"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chromite","name":"Chromite","kind":"raw","category":"ground","title":"How chromite is mined","url":"https://assemblyline.org/make/chromite","stations":4,"upstream":0,"downstream":48,"depth":0,"dek":"Chromite forms flat black layers deep in cooled magma, some hundreds of kilometers long and only meters thick.","answer":"Chromite settles out of slow-cooling magma into thin dark layers, and miners reach them from underground or the surface. Rich lumpy ore can go straight to a furnace. The rest is crushed, screened and slurried, then run down spiral chutes where the heavy chromite hugs the inside of the curve. Cleaning passes lift it to about 42%, a grade ferrochrome smelters can use.","aka":["chrome ore"],"inputs":[],"uses":["chromium"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["chromium","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather","syringe","washing-machine","electric-kettle","wristwatch","kitchen-knife","fork","elevator","fountain-pen","thermos","water-bottle","pressure-cooker","blender","dishwasher","golf-club","asthma-inhaler","subway-train","smartwatch","jet-engine","baseball","basketball","tennis-racket","football","saxophone","winter-gloves","leather-belt","handbag","wallet","hiking-boots","high-heels","digital-camera","leather-shoe","skyscraper","airplane"],"steps":[{"name":"Follow the dark layer","process":"mine","text":"Most reserves lie in stratiform deposits, thin even layers spread over a broad area, and pod-shaped deposits matter too. Both underground and surface methods are used. Rich lump ore above 46% chromic oxide can go directly to ferrochromium production.","inputs":[]},{"name":"Crush and screen","process":"crush","text":"Ore is crushed and screened into size fractions. The fine fraction, typically 1.0 mm or less, is mixed with water to a set density and deslimed to remove ultrafine particles.","inputs":[]},{"name":"Run the spirals","process":"separate","text":"Slurry is pumped to the top of a spiral and flows around it. Fast-settling heavy grains drift to the inside of the channel, while light waste rides the faster water on the outside and heads to tailings.","inputs":[]},{"name":"Clean to smelter grade","process":"separate","text":"The chromite stream passes through cleaning and recleaning spirals that remove misplaced waste. Grade climbs to typically 42%, ready for ferrochrome smelters, and spirals can also make chemical and foundry grades.","inputs":[],"spec":"typically 42%"}],"facts":["Chromite forms inside slow-cooling magma and also occurs in iron meteorites.","The Bushveld in South Africa is one of the great chromite-bearing intrusions.","Tailings thrown out by platinum concentrators in the Bushveld are rich enough in chromite to be run through spirals again."],"where":[],"whereNote":null,"sources":[{"title":"Chromium processing","url":"https://www.britannica.com/technology/chromium-processing"},{"title":"Spiral separation for optimised recovery","url":"https://www.crown.co.za/latest-news/mechchem-africa-latest-news/28505-spiral-separation-for-optimised-recovery"},{"title":"Chromite","url":"https://en.wikipedia.org/wiki/Chromite"},{"title":"Chromium","url":"https://en.wikipedia.org/wiki/Chromium"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chromium","name":"Chromium","kind":"material","category":"metals","title":"How chromium is made","url":"https://assemblyline.org/make/chromium","stations":6,"upstream":24,"downstream":47,"depth":5,"dek":"Most chromium never becomes a pure metal. It is smelted with iron into ferrochrome and goes straight into stainless steel.","answer":"Chromium is made from chromite ore. For stainless steel, chromite is smelted with coal and coke in an electric arc furnace into ferrochrome, an iron-chromium alloy with 50 to 70 percent chromium. Pure chromium takes a longer path: the ore is roasted with carbonates, leached to a chromium compound, and reduced with aluminum.","aka":["chrome","ferrochrome","chromium metal"],"inputs":["chromite","coke","soda-ash","limestone","air","water","aluminum"],"uses":["hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather"],"grounds":["chromite","limestone","air","water","coal","rock-salt","trona","crude-oil","natural-gas","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["chromite","coke","soda-ash","limestone","air","water","aluminum","coal","rock-salt","ammonia","carbon-dioxide","lime","trona","crude-oil","petroleum-coke","alumina","natural-gas","corn","yeast","bauxite","caustic-soda","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather","syringe","washing-machine","electric-kettle","wristwatch","kitchen-knife","fork","elevator","fountain-pen","thermos","water-bottle","pressure-cooker","blender","dishwasher","golf-club","asthma-inhaler","subway-train","smartwatch","jet-engine","baseball","basketball","tennis-racket","football","saxophone","winter-gloves","leather-belt","handbag","wallet","hiking-boots","high-heels","digital-camera","leather-shoe","skyscraper","airplane"],"steps":[{"name":"Mine the chromite","process":"mine","text":"Chromite, an iron-chromium oxide, is dug mostly in South Africa and Kazakhstan. About 28.8 million metric tons of marketable ore were produced in 2013.","inputs":["chromite"]},{"name":"Smelt it in an arc furnace","process":"melt","text":"Huge electric arcs between electrodes in the furnace bottom reach about 2,800 °C. Coal and coke take the oxygen from the chromite, and an iron-chromium alloy forms.","inputs":["coke"],"spec":"about 2,800 °C"},{"name":"Tap and crush the ferrochrome","process":"cast","text":"When enough has gathered, the tap hole is drilled open and molten ferrochrome and slag rush down a trough. The metal freezes in large castings that are crushed for sale. This alloy is 50 to 70 percent chromium, and stainless steel is its main customer.","inputs":[]},{"name":"Roast the ore for pure metal","process":"fire","text":"For metal free of iron, chromite is heated in air with calcium carbonate and sodium carbonate. The chromium turns into a soluble form, and the iron becomes stable iron oxide that stays behind.","inputs":["soda-ash","limestone","air"]},{"name":"Leach and convert to oxide","process":"wash","text":"Hot leaching washes the soluble chromium compound away from the iron. It is converted to dichromate, and carbon then reduces that to chromium(III) oxide.","inputs":["water"]},{"name":"Reduce it with aluminum","process":"react","text":"In an aluminothermic reaction, aluminum powder takes the oxygen from the chromium oxide and leaves chromium metal.","inputs":["aluminum"]}],"facts":["Stainless steel and chrome plating together account for 85 percent of commercial chromium use.","Chromium is the third hardest element, after carbon in the form of diamond and boron.","Chromium(III) is considered non-toxic, but hexavalent chromium, found in chromates, is toxic and carcinogenic."],"where":[{"place":"South Africa","share":"48% of chromite ore"},{"place":"Kazakhstan","share":"13%"},{"place":"Turkey","share":"11%"},{"place":"India","share":"10%"}],"whereNote":"2013, share of world chromium ore production.","sources":[{"title":"Chromium","url":"https://en.wikipedia.org/wiki/Chromium"},{"title":"Ferrochrome","url":"https://en.wikipedia.org/wiki/Ferrochrome"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cinnabar","name":"Cinnabar","kind":"raw","category":"ground","title":"How cinnabar is mined","url":"https://assemblyline.org/make/cinnabar","stations":3,"upstream":0,"downstream":2,"depth":0,"dek":"This soft scarlet rock has a specific gravity of 8.1, extremely high for a mineral that is not a metal.","answer":"Hot water rising through cracked rock near recent volcanic activity leaves cinnabar behind as bright red coatings and vein fillings. Miners follow those veins through tunnels, sometimes hundreds of meters down. Even rich rock is mostly waste, since the best mercury ores hold only 2.5% of the metal. Cinnabar is mercury sulfide, the main source of mercury.","aka":["cinnabarite","mercury sulfide","vermilion ore"],"inputs":[],"uses":["mercury"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["mercury","neon-sign"],"steps":[{"name":"Trace the red veins","process":"mine","text":"Cinnabar forms at shallow depth, below about 200 degrees Celsius, where hot fluids cool in fractured rock. Its color makes it easy to spot in the field, usually alongside quartz, dolomite, calcite or barite.","inputs":[]},{"name":"Tunnel along the ore","process":"mine","text":"Miners drive shafts and galleries to reach the deposit. The old lower levels at Idrija in Slovenia extend almost 400 meters down. Mining this ore has long been a cause of mercury poisoning, and the rock itself counts as a toxic material.","inputs":[]},{"name":"Bring up the rock","process":"mine","text":"Broken ore leaves the mine for crushing, ahead of the furnace. Grades run from about 0.1% mercury in lean concentrated deposits to 2.5% in the richest.","inputs":[]}],"facts":["A woman buried in the 7th-century tomb of the Red Queen at Palenque was covered in bright red cinnabar powder.","Cinnabar has the second-highest refractive index of any mineral.","Chinese carved lacquerware got its famous red from cinnabar, a technique that seems to date to the Song dynasty."],"where":[],"whereNote":null,"sources":[{"title":"Cinnabar","url":"https://en.wikipedia.org/wiki/Cinnabar"},{"title":"Cinnabar, Geology.com","url":"https://geology.com/minerals/cinnabar.shtml"},{"title":"Idrija","url":"https://en.wikipedia.org/wiki/Idrija"},{"title":"Mercury (element)","url":"https://en.wikipedia.org/wiki/Mercury_(element)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"clay","name":"Clay","kind":"raw","category":"ground","title":"How clay is dug","url":"https://assemblyline.org/make/clay","stations":3,"upstream":0,"downstream":178,"depth":0,"dek":"Clay is the oldest ceramic ingredient: people were firing it into pottery around 14,000 BCE.","answer":"Clay is soil made of microscopic plates of aluminum silicate minerals. It is dug from open pits where the layer is thick and clean, stockpiled, and often left to weather. Its tiny flat particles hold water, which makes wet clay moldable and lets it harden when dried or fired.","aka":["potter's clay","brick clay"],"inputs":[],"uses":["pencil","cement","brick","roof-tile","ceramic","coffee-mug","dinner-plate","toilet","vegetable-oil","bell","bronze-statue","floor-tile","pottery"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["pencil","cement","brick","roof-tile","ceramic","coffee-mug","dinner-plate","toilet","vegetable-oil","bell","bronze-statue","floor-tile","pottery","washing-machine","concrete","hip-implant","faucet","turbine-blade","soap","shampoo","deodorant","sunscreen","mascara","detergent","ink","glycerin","cast-iron-pan","margarine","mayonnaise","peanut-butter","tortilla","donut","sandwich-cookie","potato-chips","french-fries","canned-tuna","chicken-nuggets","baby-formula","oat-milk","crackers","fish-sticks","biodiesel","wooden-spoon","pencil-eraser","modeling-clay","cake-mix","foundation-makeup","skyscraper","jet-engine","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","toothpaste","chewing-gum","snow-globe","cough-syrup","gelatin-capsule","diesel","airplane","vacuum-cleaner","electric-kettle","cotton-candy","pillow","paint","condensed-milk","coconut-milk","canned-meat","canned-soup","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","car","electric-car","nitrile-glove","paperclip","corn-flakes","popcorn","crayon","fireworks","candle","salsa","zip-bag","blender","dishwasher","cotton-swab","mouthwash","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","locomotive","refrigerator","microwave-oven","scissors","mirror","container-ship","shipping-container","bicycle","motorcycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","toy-car","coil-spring","hammer","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","padlock"],"steps":[{"name":"Dig the clay pit","process":"mine","text":"Clay lies in beds, often mixed with silt. Diggers strip the soil above a thick clean layer and excavate it with shovels and loaders.","inputs":[]},{"name":"Pick out stones and roots","process":"separate","text":"The raw clay is screened or crushed to remove stones and plant material, so that the finished product has the same texture all the way through.","inputs":[]},{"name":"Stockpile and weather","process":"dry","text":"Clay is stacked in the open, where rain and frost break lumps apart and water spreads evenly. Users then add water until it reaches the plasticity they need.","inputs":[]}],"facts":["Shale, which is made largely of clay, is the most common sedimentary rock.","Clay minerals are tiny thin plates, which gives them a very high surface area for their size."],"where":[],"whereNote":null,"sources":[{"title":"Clay","url":"https://en.wikipedia.org/wiki/Clay"},{"title":"Kaolinite","url":"https://en.wikipedia.org/wiki/Kaolinite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"clear-tape","name":"Clear adhesive tape","kind":"product","category":"plastics","title":"How clear adhesive tape is made","url":"https://assemblyline.org/make/clear-tape","stations":6,"upstream":35,"downstream":0,"depth":9,"dek":"Clear sticky tape began in 1930, when Richard Drew at 3M put adhesive on cellophane.","answer":"Clear tape is a transparent plastic or cellophane film coated on one side with a pressure-sensitive adhesive. Corona treatment roughens the film so glue grips it. The coated film dries in an oven, winds onto a wide jumbo roll, and is slit into narrow strips rewound onto cores.","aka":["Scotch tape","Sellotape","cellophane tape","sticky tape"],"inputs":["polypropylene","adhesive","cardboard"],"uses":[],"grounds":["water","crude-oil","timber","natural-gas","air","sulfur","rock-salt","limestone","coal"],"upstreamSlugs":["polypropylene","adhesive","cardboard","propylene","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","wood-pulp","naphtha","crude-oil","ethylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","hydrogen","timber","lime","oxygen","hydrogen-peroxide","natural-gas","air","sulfur","benzene","rock-salt","limestone","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Make the clear film","process":"extrude","text":"Most modern tape uses polypropylene film that has been stretched in both directions. This stretching makes it strong and crystal clear. Older tape used cellophane.","inputs":["polypropylene"]},{"name":"Corona-treat one side","process":"coat","text":"A high-voltage discharge roughens one face of the film, so the adhesive will wet it evenly and grip.","inputs":[]},{"name":"Coat one side with adhesive","process":"coat","text":"An acrylic or hot-melt adhesive is spread on the treated face in an even layer, and the film passes through a drying oven. The adhesive then sticks on contact, with no water or heat needed to activate it.","inputs":["adhesive"]},{"name":"Wind a jumbo roll","process":"package","text":"The coated film is wound onto a very wide mother roll, many times wider than any roll you could buy.","inputs":[]},{"name":"Slit to width","process":"cut","text":"A slitting machine divides the jumbo roll into narrow rolls, which are rewound onto cardboard cores.","inputs":["cardboard"]},{"name":"Pack into dispensers","process":"package","text":"Finished rolls are packed in dispensers or cartons and sent out.","inputs":[]}],"facts":["The Scotch name came from a 1925 joke: a painter testing Drew's first masking tape told him to take it back to his Scotch bosses, meaning stingy.","Peeling tape in a vacuum can give off enough X-rays to leave an image of a finger on photographic paper.","Clear tape with a matte finish is sold as Scotch Magic Tape or called invisible tape."],"where":[],"whereNote":null,"sources":[{"title":"Scotch Tape","url":"https://en.wikipedia.org/wiki/Scotch_Tape"},{"title":"Pressure-sensitive tape","url":"https://en.wikipedia.org/wiki/Pressure-sensitive_tape"},{"title":"Biaxially-oriented polypropylene","url":"https://en.wikipedia.org/wiki/Biaxially-oriented_polypropylene"},{"title":"BOPP Tape FAQs","url":"https://www.jotamachinery.com/about-us/faqs/roll-to-roll-faqs/bopp-tape-faqs/"},{"title":"Industrial packaging: BOPP tape","url":"https://www.qyangtape.com/info/industrial-packaging-bopp-tape-103160369.html"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"clothespin","name":"Clothespin","kind":"product","category":"wood-paper","title":"How clothespins are made","url":"https://assemblyline.org/make/clothespin","stations":7,"upstream":27,"downstream":0,"depth":6,"dek":"A spring clothespin is two wooden jaws and a single bent wire that works as both spring and hinge.","answer":"A spring clothespin is two small wooden jaws and a coil of steel wire. Hardwood boards are planed thin, cut into short blanks and machined with grips and notches. The blanks are ripped into halves and tumbled smooth. A machine bends wire into a spring, and the jaws are fitted together around the coil.","aka":["clothes peg","clothes pin","peg"],"inputs":["lumber","steel-wire"],"uses":[],"grounds":["timber","iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","coal","quartz","crude-oil","sulfur"],"upstreamSlugs":["lumber","steel-wire","timber","steel","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","coal","quartz","charcoal","crude-oil","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Plane boards and crosscut","process":"cut","text":"Dried hardwood boards are planed thin, then crosscut into short blanks as long as a pin. Waste lumber fed the old Vermont factories.","inputs":["lumber"]},{"name":"Machine the grips and notches","process":"machine","text":"Saws and routers cut grip grooves and the notch that will seat the spring across each blank, so one blank holds the profile of many jaws.","inputs":[]},{"name":"Rip out the halves","process":"cut","text":"The mouth and handle ends are ripped at a slight angle, then final cuts slice the blank into separate jaws.","inputs":[]},{"name":"Tumble them smooth","process":"grind","text":"The jaws tumble together so the sharp edges rub each other round. Some makers add an oil-dampened cloth for a finish.","inputs":[]},{"name":"Coil the spring","process":"stamp","text":"Steel wire is bent into one spring with a loop in the middle. The loop is the coiled fulcrum, the part that lets the two halves rock like a seesaw, and the two arms push the jaws shut.","inputs":["steel-wire"]},{"name":"Clip the jaws on","process":"assemble","text":"The spring is opened and the two jaws slide into its arms, so the coil seats in the notches. Machines do this in factories, and small shops do it by hand.","inputs":[]},{"name":"Count and pack","process":"package","text":"Finished pins are counted into bags or boxes.","inputs":[]}],"facts":["David M. Smith of Vermont invented the two-prong spring clothespin in 1853, and Solon Moore improved it in 1887 with a single-wire coiled fulcrum.","The New York Times called Vermont \"The Silicon Valley of Clothespin Manufacturing\".","Clothespin making was once a Romani craft in England, using small split lengths of willow or ash."],"where":[],"whereNote":null,"sources":[{"title":"Clothespin","url":"https://en.wikipedia.org/wiki/Clothespin"},{"title":"The humble Vermont clothespin","url":"https://vermonthistory.org/vermont-clothespin-montpelier-history"},{"title":"Wooden Clothes Peg Making Process","url":"https://www.cnwoodmachine.com/wooden-clothes-peg-making-process/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"coal","name":"Coal","kind":"raw","category":"ground","title":"How coal is mined","url":"https://assemblyline.org/make/coal","stations":3,"upstream":0,"downstream":406,"depth":0,"dek":"Nine of every ten coal beds on Earth date from just two periods, the Carboniferous and the Permian.","answer":"Coal is the buried remains of swamp forests, pressed and heated over millions of years into black seams. Shallow seams are exposed by stripping off the overburden and digging with shovels and draglines. Deep seams are cut underground, often by longwall machines. Many coals are washed in a preparation plant before shipping.","aka":["black coal","thermal coal","metallurgical coal"],"inputs":[],"uses":["synthetic-graphite","silicon","coke","aluminum","toluene","vanadium"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["synthetic-graphite","silicon","coke","aluminum","toluene","vanadium","lithium-ion-cell","synthetic-diamond","silicone","polysilicon","magnesium","trichlorosilane","titanium-dioxide","pig-iron","tin","lead","chromium","manganese","phosphoric-acid","deodorant","lipstick","microchip","led-bulb","oled-screen","ev-battery","smartphone","laptop","hard-drive","solid-state-drive","solar-cell","solar-panel","refrigerator","washing-machine","satellite","pencil","aluminum-foil","brass","cobalt","nonstick-pan","aluminum-can","mirror","skyscraper","car","electric-car","car-engine","airplane","rocket","bicycle","motorcycle","skateboard","drum-kit","pencil-eraser","pressure-cooker","toaster","air-conditioner","ceiling-fan","office-chair","ski","yo-yo","toy-car","eyeshadow","asthma-inhaler","prosthetic-leg","wheelchair","ladder","double-glazed-window","aluminum-window-frame","subway-train","sailboat","suitcase","smartwatch","microphone","camera-lens","vinyl-record","compact-disc","game-console","graphics-card","newspaper","zipper","n95-mask","benzene","wrench","drone","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","shampoo","syringe","condom","hearing-aid","contact-lens","airbag","cork-stopper","blender","foundation-makeup","remote-control","silicon-wafer","steel","titanium","water-heater","toothpaste","sunscreen","nail-polish","ink","paint","crayon","candy-coated-chocolate","pvc-pipe","pigment","cast-iron-pan","piano","dumbbell","tinplate","bronze","solder","padlock","window-glass","indium-tin-oxide","medal","bell","usb-cable","chess-set","stained-glass","car-battery","hip-implant","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","ice-skates","stent","nichrome","leather","thermometer","aa-battery","cola","soda","pacemaker","credit-card","television","computer-keyboard","computer-mouse","phone-charger","wifi-router","inkjet-printer","aspirin","wristwatch","tire","electric-guitar","trumpet","ballpoint-pen","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","light-switch","power-outlet","leather-belt","handbag","flag","tungsten-carbide","sparkling-water","beer","hard-cider","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","locomotive","down-jacket","raincoat","backpack","jeans","polystyrene","abs-plastic","nylon","synthetic-rubber","phenol","spandex","styrene","acetone","champagne","memory-chip","camera-sensor","toothbrush","wind-turbine","electric-motor","transformer","vacuum-cleaner","sheet-steel","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","ball-bearing","container-ship","shipping-container","elevator","rubiks-cube","wine-barrel","dishwasher","snowboard","golf-club","fishing-rod","dental-floss","barbed-wire","hammer","drill-bit","spark-plug","seat-belt","high-heels","eyeglass-frame","loudspeaker","jet-engine","plastic-bag","tin-can","windshield","golf-ball","baseball","basketball","soccer-ball","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","floor-tile","vinyl-floor","underwear","flip-flops","cardboard-box","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","microwave-oven","electric-kettle","wooden-chair","water-bottle","tennis-racket","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","coil-spring","wheelbarrow","neon-sign","suspension-bridge-cable","brake-pad","mascara","pvc","lego-brick","lcd-screen","porcelain","chalk","candy-cane","sprinkles","plastic-straw","printer-toner","towel","canned-tuna","air-freshener","hairspray","bronze-statue","printed-circuit-board","flute","smoke-detector","kitchen-knife","fork","thermos","football","winter-gloves","wallet","hiking-boots","leather-shoe","saw-blade","surfboard","bike-helmet","polystyrene-foam","foam-cup","3d-printer-filament","headphones","guitar","violin","velcro","roller-skates","volleyball","kite","ukulele","drumstick","leggings","swimsuit","socks","carpet","rope","rubber","nitrile-glove","chewing-gum","rubber-boots","acetaminophen","polycarbonate","epoxy","phenolic-resin","shoelace","cellulose-acetate","treadmill","shovel","wire-rope","nail","screw","paperclip","needle","clothespin","staple","sofa","slinky","cello","bolt","chain","chain-link-fence","mattress","concrete","wine","bourbon","scotch","cognac","port-wine","cotton-candy","pillow","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","soap","detergent","donut","corn-flakes","popcorn","fireworks","candle","salsa","fish-sticks","zip-bag","cotton-swab","mouthwash","cough-syrup","facial-tissue","envelope","plastic-wrap","yoga-mat","inflatable-pool-toy","power-cable","pinball-machine","tennis-ball","cricket-bat","sneaker","eyeglass-lens","sunglasses","adhesive","photoresist","toffee","adhesive-bandage","duct-tape","insulation","paper-straw","paper-bag","door","clear-tape","kitchen-sponge","sanitary-pad","roof-shingle","dress-shirt","suit","plywood","mdf","cardboard","toilet-paper","match","baseball-cap","diaper","cake-mix","hair-dye","tampon"],"steps":[{"name":"Strip the overburden","process":"mine","text":"Where a seam lies close to the surface, the rock and soil above it are drilled, blasted and removed in long strips. Draglines and electric shovels do the heavy lifting.","inputs":[]},{"name":"Cut the deep seam","process":"mine","text":"Underground, the most economical method is longwall mining. Two spinning drums fitted with carbide bits run back and forth along a long section of the seam, and the roof is allowed to collapse behind the machine.","inputs":[]},{"name":"Wash the coal","process":"wash","text":"Many coals from both surface and underground mines go through a preparation plant, which washes away rock and other impurities.","inputs":[]}],"facts":["In 2020, coal supplied about a quarter of the world's primary energy and over a third of its electricity.","Longwall mining accounts for about 50 percent of underground coal production."],"where":[{"place":"China","share":"almost half of the world's coal"},{"place":"India","share":"about a tenth"}],"whereNote":"Share of world coal mined, as given in the Wikipedia coal article.","sources":[{"title":"Coal","url":"https://en.wikipedia.org/wiki/Coal"},{"title":"Coal mining","url":"https://en.wikipedia.org/wiki/Coal_mining"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cobalt","name":"Cobalt","kind":"material","category":"metals","title":"How cobalt is made","url":"https://assemblyline.org/make/cobalt","stations":6,"upstream":15,"downstream":21,"depth":4,"dek":"Almost all cobalt is a byproduct of mining copper or nickel, so its supply follows those metals.","answer":"Cobalt is usually produced as a byproduct of copper and nickel mining. Ore from places such as the Copperbelt is floated to a concentrate and roasted, then leached with water and sulfuric acid to pull out cobalt salts. These are converted into cobalt oxide, which is reduced to metal with aluminum or carbon.","aka":["cobalt metal","refined cobalt"],"inputs":["cobalt-ore","sulfuric-acid","aluminum"],"uses":["hip-implant","lithium-ion-cell","hard-drive","turbine-blade","tungsten-carbide","stent"],"grounds":["cobalt-ore","sulfur","air","water","crude-oil","coal","bauxite","rock-salt","limestone"],"upstreamSlugs":["cobalt-ore","sulfuric-acid","aluminum","sulfur","air","water","crude-oil","coal","petroleum-coke","alumina","bauxite","caustic-soda","lime","rock-salt","limestone"],"downstreamSlugs":["hip-implant","lithium-ion-cell","hard-drive","turbine-blade","tungsten-carbide","stent","ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","jet-engine","ballpoint-pen","saw-blade","electric-car","airplane"],"steps":[{"name":"Mine the copper-cobalt ore","process":"mine","text":"Cobalt is found in copper and nickel minerals, and the Copperbelt of the Democratic Republic of the Congo and Zambia supplies most of the world's cobalt. Mining is mostly aimed at the copper, and the cobalt comes with it.","inputs":["cobalt-ore"]},{"name":"Float a concentrate","process":"separate","text":"Froth flotation, with surfactants that bind to the ore minerals, enriches the cobalt-bearing ore and separates it from the waste rock.","inputs":[]},{"name":"Roast it to sulfate","process":"bake","text":"Roasting converts the cobalt minerals to cobalt sulfate, and the copper and iron to oxides, which do not dissolve in water.","inputs":[]},{"name":"Leach out the cobalt","process":"react","text":"Water takes up the sulfate along with arsenates, and the leftover residue is leached again with sulfuric acid. Cobalt can also be leached from the slag of copper smelting.","inputs":["sulfuric-acid"]},{"name":"Convert to cobalt oxide","process":"refine","text":"The various products of leaching are transformed into cobalt oxide, Co3O4, which is the form that is reduced to metal.","inputs":[]},{"name":"Reduce it to metal","process":"melt","text":"The oxide is reduced to metal by an aluminothermic reaction, in which aluminum takes the oxygen, or by carbon in a blast furnace.","inputs":["aluminum"]}],"facts":["Cobalt has colored glass blue since the Bronze Age, and the oldest cobalt-colored glass is from the eighteenth dynasty of Egypt.","The name comes from the kobold, a goblin that 16th-century German silver miners blamed for an ore that was a nuisance to them."],"where":[{"place":"Democratic Republic of the Congo","share":"more than 80% of world production"}],"whereNote":"2024, when world cobalt production exceeded 300,000 tons.","sources":[{"title":"Cobalt","url":"https://en.wikipedia.org/wiki/Cobalt"},{"title":"Froth flotation","url":"https://en.wikipedia.org/wiki/Froth_flotation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cobalt-ore","name":"Cobalt ore","kind":"raw","category":"ground","title":"How cobalt ore is mined","url":"https://assemblyline.org/make/cobalt-ore","stations":3,"upstream":0,"downstream":22,"depth":0,"dek":"Most cobalt is never mined for itself. It comes up as a side product of copper and nickel.","answer":"Cobalt mostly arrives as a passenger in copper and nickel ore, and arsenide ores, mined chiefly in Morocco, are the only primary cobalt ores. At Tenke Fungurume in the Congo, an open pit feeds plants that leach out copper and cobalt. Sulfide ore is made into a copper-cobalt concentrate, and a further flotation pulls out a cobalt-rich product.","aka":["cobaltite"],"inputs":[],"uses":["cobalt"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["cobalt","hip-implant","lithium-ion-cell","hard-drive","turbine-blade","tungsten-carbide","stent","ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","jet-engine","ballpoint-pen","saw-blade","electric-car","airplane"],"steps":[{"name":"Dig the copper pit","process":"mine","text":"Nearly all cobalt sits in ores of copper, nickel or both. At Tenke Fungurume in the Democratic Republic of the Congo, conventional open-pit mining digs copper-cobalt ore, and the plant turned out 182,597 t of copper cathode against 15,436 t of cobalt hydroxide in 2020.","inputs":[]},{"name":"Leach out the metals","process":"react","text":"At Tenke Fungurume, copper is dissolved by atmospheric leaching and recovered by solvent extraction and electrowinning. Cobalt goes through a separate sulfur dioxide leach, then purification and precipitation, and leaves as cobalt hydroxide.","inputs":[]},{"name":"Float the sulfide ore","process":"separate","text":"Sulfide ores from Congo and Zambia are first concentrated in the usual way into a copper-cobalt product. A second flotation uses reagents that pull cobalt minerals to the bubbles ahead of copper, giving a concentrate of as much as 15% cobalt.","inputs":[]}],"facts":["The Democratic Republic of the Congo accounted for more than 80% of cobalt production in 2024, when output exceeded 300,000 tons.","Cobalt blue pigments have been used since antiquity to tint glass.","Early smelters who tried to get copper or silver from cobalt ores got only powder and toxic arsenic fumes, and the name is usually traced to the German kobold, a goblin blamed for the trouble."],"where":[{"place":"Democratic Republic of the Congo","share":"more than 80% of production"}],"whereNote":"Share of world cobalt production in 2024, when output exceeded 300,000 tons.","sources":[{"title":"Cobalt processing: Mining and concentrating","url":"https://www.britannica.com/technology/cobalt-processing/Mining-and-concentrating"},{"title":"Tenke Fungurume Copper-Cobalt Mine","url":"https://www.nsenergybusiness.com/projects/tenke-fungurume-copper-cobalt-mine/"},{"title":"Cobalt","url":"https://en.wikipedia.org/wiki/Cobalt"},{"title":"Copper","url":"https://en.wikipedia.org/wiki/Copper"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cocoa-beans","name":"Cocoa beans","kind":"raw","category":"farm","title":"How cocoa beans are grown and harvested","url":"https://assemblyline.org/make/cocoa-beans","stations":4,"upstream":0,"downstream":10,"depth":0,"dek":"Cocoa pods grow straight out of the trunk, and the beans inside must be rotted a little before they taste right.","answer":"Cacao trees grow in hot, rainy land within 20 degrees of the equator, and their pods sprout directly from the trunk. Workers cut ripe pods by hand with a machete, split them open and scoop out the 30 to 50 seeds. The wet beans are piled for several days to ferment, then dried.","aka":["cacao beans","cocoa farming","cocoa harvest","cacao pods"],"inputs":[],"uses":["cocoa-butter","chocolate","cocoa-powder"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["cocoa-butter","chocolate","cocoa-powder","white-chocolate","candy-coated-chocolate","sandwich-cookie","sprinkles","hazelnut-spread","cake-mix","donut"],"steps":[{"name":"Grow in the tropics","process":"grow","text":"Cacao trees thrive only in hot, rainy places close to the equator, and a tree takes five years to start bearing. Pods are 17 to 20 cm long, with a thick leathery rind around sweet pulp and the seeds.","inputs":[]},{"name":"Cut ripe pods by hand","process":"harvest","text":"Pods ripen at different times, so pickers return three or four times a week through the season. They cut the ripe and nearly ripe ones, judged by color, with a curved knife on a long pole, taking care not to damage the spot where future flowers form.","inputs":[],"spec":"three to four visits a week"},{"name":"Crack open and pile up","process":"ferment","text":"Pods are split with a machete or knife, the rind is thrown away, and the pulp and seeds are heaped in bins or on grates for several days. The pulp liquefies and drains off, and the seeds turn from pale yellow or violet to brown.","inputs":[]},{"name":"Dry the fermented beans","process":"dry","text":"After fermenting, the beans are dried. If the sweating step is cut short, the cocoa tastes like raw potatoes and goes moldy easily, and if it is interrupted the batch can be ruined.","inputs":[]}],"facts":["About 400 dried beans are needed to make 1 pound (450 g) of chocolate.","West Africa grows nearly 81% of the world's cocoa.","The cacao tree was first domesticated at least 5,300 years ago, in what is now Ecuador."],"where":[{"place":"Ivory Coast","share":"38% of world output"},{"place":"Ghana","share":"second largest producer"},{"place":"Indonesia","share":"third largest producer"}],"whereNote":"2024, share of the 5.8 million tonnes of cocoa beans produced worldwide.","sources":[{"title":"Cocoa bean","url":"https://en.wikipedia.org/wiki/Cocoa_bean"},{"title":"Chocolate","url":"https://en.wikipedia.org/wiki/Chocolate"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cocoa-butter","name":"Cocoa butter","kind":"material","category":"food","title":"How cocoa butter is made","url":"https://assemblyline.org/make/cocoa-butter","stations":6,"upstream":1,"downstream":3,"depth":1,"dek":"Cocoa butter melts just below body temperature, which is why a chocolate bar snaps in your hand and goes liquid in your mouth.","answer":"Cocoa butter is the pale fat squeezed out of ground cocoa beans. The beans are fermented, dried, roasted and shelled, and the nibs are milled into a paste called liquor. A hydraulic press then forces the fat out of the paste, leaving a dry cake of cocoa solids behind. The butter is sometimes deodorized before it is sold.","aka":["theobroma oil","cacao butter"],"inputs":["cocoa-beans"],"uses":["chocolate","white-chocolate"],"grounds":["cocoa-beans"],"upstreamSlugs":["cocoa-beans"],"downstreamSlugs":["chocolate","white-chocolate","candy-coated-chocolate"],"steps":[{"name":"Heap the beans to ferment","process":"ferment","text":"Beans and their sticky pulp are piled in bins and left alone. Wild yeasts make alcohol, then bacteria turn it into lactic and acetic acid, and the chemistry starts building the flavor precursors that will later taste like chocolate.","inputs":["cocoa-beans"],"spec":"up to 7 days"},{"name":"Spread them in the sun","process":"dry","text":"Fermented beans are dried before mold can take hold. Where the weather allows, growers spread them out in the open air and rake them over for days.","inputs":[],"spec":"5 to 7 days"},{"name":"Roast and strip the shells","process":"bake","text":"At the factory the beans are cleaned of twigs and stones, roasted and graded. Each bean is then cracked and its shell removed, leaving small pieces of kernel called nibs.","inputs":[]},{"name":"Grind the nibs to paste","process":"crush","text":"Milling breaks open the cells of the nib and the fat inside melts. The dry crumbs turn into a thick, free-flowing paste called cocoa liquor or cocoa mass. More than half of that paste is fat.","inputs":[],"spec":"54–58% of the nib is fat"},{"name":"Press out the fat","process":"press","text":"The warm liquor is put under very high pressure. Golden fat runs out through the cloth and a hard cake of defatted cocoa is left behind. That cake is later milled into cocoa powder.","inputs":[]},{"name":"Strip off stray flavors","process":"refine","text":"Some cocoa butter is deodorized to take out strong or unwanted tastes. The pale, mild fat is then filtered and cooled into blocks for chocolate makers.","inputs":[]}],"facts":["Cocoa butter melts at around 34 to 38 °C, a little below body temperature, so it is solid on a shelf and liquid on the tongue.","Cocoa butter can crystallize in six different forms, and only one of them gives chocolate its snap and shine.","Despite the name, cocoa butter contains no dairy. It is vegan.","For centuries cocoa butter was a by-product that factories sold for cosmetics and medicine, until chocolate bars made it the valuable part."],"where":[],"whereNote":null,"sources":[{"title":"Cocoa butter","url":"https://en.wikipedia.org/wiki/Cocoa_butter"},{"title":"Chocolate liquor","url":"https://en.wikipedia.org/wiki/Chocolate_liquor"},{"title":"Chocolate","url":"https://en.wikipedia.org/wiki/Chocolate"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cocoa-powder","name":"Cocoa powder","kind":"product","category":"food","title":"How cocoa powder is made","url":"https://assemblyline.org/make/cocoa-powder","stations":7,"upstream":1,"downstream":5,"depth":1,"dek":"Cocoa powder is what is left when about half the bean, the fat, is squeezed out by a press.","answer":"Fermented, dried cocoa beans are roasted, cracked and shelled into nibs. The nibs are ground into a thick liquor, and a hydraulic press squeezes out the cocoa butter. The dry cake that remains is pulverized into powder. Treating the nibs, liquor or cake with an alkali gives darker, milder Dutch-process cocoa.","aka":["cacao powder","Dutch-process cocoa","baking cocoa"],"inputs":["cocoa-beans"],"uses":["sandwich-cookie","sprinkles","hazelnut-spread","cake-mix"],"grounds":["cocoa-beans"],"upstreamSlugs":["cocoa-beans"],"downstreamSlugs":["sandwich-cookie","sprinkles","hazelnut-spread","cake-mix","donut"],"steps":[{"name":"Ferment and dry the beans","process":"ferment","text":"At the farm, beans and pulp are piled to sweat for three to seven days. The pulp ferments and drains away, and the beans turn from pale to brown before they are dried for shipping.","inputs":["cocoa-beans"],"spec":"3 to 7 days"},{"name":"Roast the beans","process":"bake","text":"Roasting develops flavor, and time and temperature steer the result. A low roast gives a more acid, aromatic flavor, while a high roast tastes more intense and bitter.","inputs":[]},{"name":"Crack and shell into nibs","process":"crush","text":"Beans are cracked and deshelled, leaving pieces called nibs. The skin is released easily by winnowing after roasting.","inputs":[]},{"name":"Dutch the nibs","process":"react","text":"For Dutch-process cocoa, nibs are treated with an alkaline solution, most often potassium carbonate in water, then heated under controlled conditions. Alkali raises the pH, which darkens the color and mellows the bitterness.","inputs":[]},{"name":"Grind to liquor","process":"grind","text":"Nibs are ground into a thick paste called cocoa liquor. The cocoa butter in the nibs melts under grinding, which is why the paste flows.","inputs":[]},{"name":"Press out the butter","process":"press","text":"A hydraulic press squeezes the liquor to separate the cocoa butter from the non-fat solids. The butter goes on to make chocolate. What stays behind is a dry, hard press cake.","inputs":[]},{"name":"Pulverize the cake","process":"crush","text":"The press cake is broken up and ground into a fine powder. Cocoa powder may keep a fat content of around 12 percent.","inputs":[]}],"facts":["Coenraad van Houten's father developed the hydraulic press for removing fat from cocoa beans around 1828.","Producing 1 kilogram of chocolate takes around 300 to 600 cocoa beans."],"where":[],"whereNote":null,"sources":[{"title":"Cocoa bean","url":"https://en.wikipedia.org/wiki/Cocoa_bean"},{"title":"Dutch process chocolate","url":"https://en.wikipedia.org/wiki/Dutch_process_chocolate"},{"title":"Cocoa butter","url":"https://en.wikipedia.org/wiki/Cocoa_butter"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"coconut-milk","name":"Coconut milk","kind":"product","category":"food","title":"How coconut milk is made","url":"https://assemblyline.org/make/coconut-milk","stations":6,"upstream":61,"downstream":0,"depth":9,"dek":"Canned coconut milk is shredded coconut flesh squeezed with hot water, then heated carefully because it curdles at 80 °C.","answer":"Mature coconuts are deshelled, and machines shred the white flesh. The shreds are mixed with hot water and pressed through an extractor to squeeze out a milky liquid. That liquid is filtered, pasteurized gently so it does not curdle, sealed into cans or pouches and cooled. Cream rises to the top of the can.","aka":["coconut cream","canned coconut milk"],"inputs":["coconuts","water","tin-can"],"uses":[],"grounds":["coconuts","water","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","limestone","dolomite","manganese-ore","natural-gas","coal","rock-salt","quartz","timber","sugar-beet"],"upstreamSlugs":["coconuts","water","tin-can","tinplate","lacquer","ink","steel","tin","ethanol","acrylic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","tin-ore","coke","corn","sugarcane","yeast","ethylene","propylene","ammonia","sulfuric-acid","methanol","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","iron-ore","sulfur","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","coal","molasses","naphtha","hydrogen","benzene","rock-salt","quartz","charcoal","timber","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Pick mature nuts","process":"harvest","text":"Only mature coconuts have enough white flesh and oil to make a rich milk. Young nuts are mostly water.","inputs":["coconuts"]},{"name":"Deshell and shred the flesh","process":"crush","text":"Deshelling machines strip the husk and shell. Motorized shredders and grinders then turn the white flesh into wet shreds, replacing the hand-cranked graters used at home in the tropics.","inputs":[]},{"name":"Press out the milk","process":"press","text":"Shreds are mixed with a little hot water and squeezed in an extractor. Hot water helps free the fat suspended inside the flesh. The first pressing is the richest. Later pressings of the same shreds give thinner milk.","inputs":["water"]},{"name":"Filter through fine mesh","process":"separate","text":"The liquid goes through a fine filter to catch bits of fiber before heating.","inputs":[],"spec":"100 mesh filter"},{"name":"Heat gently to pasteurize","process":"pasteurize","text":"Coconut milk is heated indirectly by double boiling. The proteins that hold the emulsion together start to coagulate at 80 °C, so the temperature is kept below that.","inputs":[],"spec":"about 70 °C, never above 80 °C"},{"name":"Seal into cans","process":"fill","text":"The milk goes straight into filling vessels and is sealed in cans, bottles or pouches before it cools. Canned milk often separates on standing, with a thick paste of cream floating at the top. Some brands add emulsifiers and homogenize to stop that.","inputs":["tin-can"]}],"facts":["Fresh coconut milk turns rancid after a few hours at room temperature, which is why canning mattered.","Coconut milk is squeezed from the white flesh, so it is a different thing from the clear water inside the nut.","Coconut milk powder is made by adding maltodextrin and casein to coconut cream and spray drying it."],"where":[],"whereNote":null,"sources":[{"title":"Coconut milk","url":"https://en.wikipedia.org/wiki/Coconut_milk"},{"title":"Canning","url":"https://en.wikipedia.org/wiki/Canning"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"coconut-oil","name":"Coconut oil","kind":"product","category":"food","title":"How coconut oil is made","url":"https://assemblyline.org/make/coconut-oil","stations":6,"upstream":2,"downstream":0,"depth":2,"dek":"A thousand coconuts weigh about 1,440 kilograms but give only about 70 liters of oil.","answer":"Most coconut oil comes from copra, which is coconut flesh dried in the sun, over fire or in kilns. Presses squeeze the oil out of the copra, and processors often add a solvent to recover more. The crude oil is refined, bleached and deodorized to remove flavor and extend shelf life, while virgin oil skips most of that.","aka":["copra oil","virgin coconut oil","coconut fat"],"inputs":["coconuts","copra"],"uses":[],"grounds":["coconuts"],"upstreamSlugs":["coconuts","copra"],"downstreamSlugs":[],"steps":[{"name":"Pick mature coconuts","process":"harvest","text":"Coconuts can be picked anywhere from 2 to 20 months old. Copra from immature nuts is harder to work and gives less oil, so picking at the right age matters to the yield.","inputs":["coconuts"]},{"name":"Dry the flesh into copra","process":"dry","text":"The flesh is cut from the shell and dried with fire, sunlight or kilns. Good copra keeps its moisture low, because damp copra spoils and the oil goes rancid.","inputs":[],"spec":"moisture below 6%"},{"name":"Press the copra","process":"press","text":"Rotary mills and expellers squeeze the oil out of the dried flesh. Heated hydraulic presses pull out practically all of it, more than 60 percent of the dry weight.","inputs":["copra"]},{"name":"Wash the cake with solvent","process":"separate","text":"Many processors soak the pressed cake in hexane, a solvent that dissolves out up to 10 percent more oil than presses alone. What is left is a high-fiber meal that is fed to ruminants.","inputs":[]},{"name":"Refine, bleach and deodorize","process":"refine","text":"Crude oil carries contaminants and is unfit to eat. Heating and filtering strip out free fatty acids, color and smell, leaving a neutral oil with a longer shelf life.","inputs":[]},{"name":"Fill the containers","process":"fill","text":"The finished oil is a clear liquid when warm and a white solid below about 24 °C. It goes into jars, drums and tankers.","inputs":[]}],"facts":["Coconut oil melts at about 24 °C, so a jar sitting in a warm kitchen switches between liquid and solid.","A wet process that skips copra and starts from fresh coconut milk gives about 10 to 15 percent less oil than the dry route."],"where":[],"whereNote":null,"sources":[{"title":"Coconut oil","url":"https://en.wikipedia.org/wiki/Coconut_oil"},{"title":"Coconut milk","url":"https://en.wikipedia.org/wiki/Coconut_milk"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"coconuts","name":"Coconuts","kind":"raw","category":"farm","title":"How coconuts are grown and harvested","url":"https://assemblyline.org/make/coconuts","stations":4,"upstream":0,"downstream":3,"depth":0,"dek":"A coconut is a fruit with three layers, and the husk alone becomes rope fiber.","answer":"Coconuts grow on tall palms that flower and fruit all year round. A tree commonly yields fewer than 30 fruits a year, and each takes 11 to 13 months from flower to maturity. The harvest is stripped of its fibrous husk, which is sold as coir, before the nuts are shipped.","aka":["coconut","coconut palm","copra"],"inputs":[],"uses":["coconut-milk","coconut-oil","copra"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["coconut-milk","coconut-oil","copra"],"steps":[{"name":"Plant palms in warm rain","process":"grow","text":"Coconut palms like heavy rain and full sun and cannot take cold. Trees can grow up to 30 meters tall and flower, set fruit and grow leaves all year.","inputs":[],"spec":"up to 30 m tall"},{"name":"Wait for the nuts to mature","process":"grow","text":"Immature nuts at 6 to 8 months are sold for coconut water. Mature nuts need 11 to 13 months from flowering before they are picked.","inputs":[],"spec":"11 to 13 months from flower"},{"name":"Strip the fibrous husk","process":"separate","text":"The husk, made of fiber called coir, is removed to cut weight for shipping. What remains is the familiar hard shell with three pores.","inputs":[]},{"name":"Dry the flesh into copra","process":"dry","text":"The white flesh is cut out and dried into copra, the form pressed for oil. Shells are burned into charcoal.","inputs":[]}],"facts":["In 2024 world production of coconuts was 65.5 million tonnes, with 73 percent from Indonesia, India and the Philippines.","Botanically a coconut is a drupe, not a true nut.","De-husked coconuts keep only two to three weeks at 12 to 15 °C, far less than nuts with the husk still on."],"where":[{"place":"Indonesia, India and the Philippines together","share":"73% of world production"}],"whereNote":"2024 world production of 65.5 million tonnes (Wikipedia).","sources":[{"title":"Coconut","url":"https://en.wikipedia.org/wiki/Coconut"},{"title":"Coconut oil","url":"https://en.wikipedia.org/wiki/Coconut_oil"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"coffee-cherries","name":"Coffee cherries","kind":"raw","category":"farm","title":"How coffee cherries are grown and harvested","url":"https://assemblyline.org/make/coffee-cherries","stations":3,"upstream":0,"downstream":5,"depth":0,"dek":"A coffee bean is the seed of a red fruit, and the fruit must be picked at peak ripeness or the flavor suffers.","answer":"Coffee grows as shrubs between the tropics of Cancer and Capricorn. Seedlings are raised in a nursery for six to twelve months before being planted out. The berries are either picked selectively by hand at peak ripeness or strip-picked all at once, by people or machines, regardless of ripeness.","aka":["coffee berries","coffee farming","coffee harvest","arabica cherries"],"inputs":[],"uses":["coffee","decaf-coffee","caffeine"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["coffee","decaf-coffee","caffeine","instant-coffee","energy-drink"],"steps":[{"name":"Nurse the seedlings","process":"grow","text":"In Brazil seedlings are raised in nurseries and moved to the field after six to twelve months. The traditional alternative is to drop 20 seeds into each hole at the start of the rains, which wastes about half of them because they fail to sprout.","inputs":[]},{"name":"Intercrop in the early years","process":"grow","text":"In the first few years, while farmers learn what the plants need, coffee is often grown between food crops such as corn, beans or rice. The plants thrive in a band between the tropics called the coffee belt.","inputs":[]},{"name":"Pick the ripe cherries","process":"harvest","text":"Pickers walk the same trees repeatedly for selective picking, which is slow, careful hand work. A strip picker clears a whole branch in one pass, by hand or by machine.","inputs":[]}],"facts":["Coffee reached Brazil in 1727, and by 1852 Brazil was the largest producer in the world.","In one repeated legend, Kaldi, a 9th-century goatherd, saw his flock energized by chewing the coffee plant.","The two main bean types are Coffea arabica and Coffea robusta."],"where":[{"place":"Brazil","share":"31% of world output"},{"place":"Vietnam","share":"second"}],"whereNote":"2023, share of world coffee bean production as given in the Wikipedia coffee article.","sources":[{"title":"Coffee","url":"https://en.wikipedia.org/wiki/Coffee"},{"title":"Coffee production","url":"https://en.wikipedia.org/wiki/Coffee_production"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"coffee-mug","name":"Coffee mug","kind":"product","category":"minerals","title":"How coffee mugs are made","url":"https://assemblyline.org/make/coffee-mug","stations":8,"upstream":2,"downstream":0,"depth":1,"dek":"Each plaster mold can press about 1,000 mug bodies before it wears out, and a press makes handles six at a time.","answer":"At the East Fork pottery, clay is pushed through a pug mill, pressed into a spinning plaster mold and shaped inside by a steel die. A hydraulic ram press makes the handles six at a time, and slip glues them on. After drying, each mug gets a first firing, a glaze dip and a second firing. Many factories slip cast instead.","aka":["ceramic mug","coffee cup","tea mug"],"inputs":["clay","water"],"uses":[],"grounds":["clay","water"],"upstreamSlugs":["clay","water"],"downstreamSlugs":[],"steps":[{"name":"Pug the clay","process":"extrude","text":"Clay goes through a pug mill that squeezes out air bubbles and extrudes long, smooth cylinders called pugs, sized for one product.","inputs":["clay"]},{"name":"Press the body","process":"press","text":"A machine measures a slug of clay and presses it into a plaster mold. As the round table turns, each mold meets a steel die that forms the inside and removes excess clay. Other plants pour liquid slip into plaster molds instead, and the plaster draws out the water.","inputs":[]},{"name":"Dry and trim","process":"cut","text":"Dryers under the molds firm the clay enough to handle in around 15 minutes. Each body comes out, and hands clean up edges and crevices.","inputs":[]},{"name":"Ram-press the handles","process":"press","text":"Hydraulic pressure pushes clay into a plaster die that forms six handles at once. Once dry enough, they are cleaned by hand and sized on a taut wire cutter.","inputs":["clay"]},{"name":"Stick on the handle","process":"assemble","text":"Watered-down leftover clay, called slip, is dabbed on the body. The spot is scored rough, and the handle is pushed on firmly enough to leave no gaps.","inputs":["water"]},{"name":"Fire the first time","process":"fire","text":"After a few days on carts the bone-dry pieces are wheeled into the kiln for their first firing, then unloaded once cool.","inputs":[]},{"name":"Dip in glaze","process":"coat","text":"A worker fills the mug with glaze and pours it out with a circular turn of the wrist, then dips the outside. A spongy conveyor belt wipes the rim clean.","inputs":[]},{"name":"Fire and finish","process":"fire","text":"A second kiln firing melts the glaze and changes its color. A machine then brushes off any stray debris before final inspection.","inputs":[]}],"facts":["A typical mug holds approximately 250–350 ml, and anything much larger is usually called a tankard.","The bottoms of mugs are often concave so that less of the base touches the table, which also leaves a ring stain.","During World War II the US Navy chose a thick white porcelain mug from Victor Insulators, a maker of high-voltage insulators."],"where":[],"whereNote":null,"sources":[{"title":"East Fork: How we make the mug","url":"https://eastfork.com/journal/how-we-make-the-mug"},{"title":"Source EC: How ceramic mugs are made","url":"https://sourceec.com.sg/corporate-gift-knowledge-detail/how-ceramic-mugs-are-made/"},{"title":"Mug","url":"https://en.wikipedia.org/wiki/Mug"},{"title":"Slip casting","url":"https://en.wikipedia.org/wiki/Slip_casting"},{"title":"Pottery","url":"https://en.wikipedia.org/wiki/Pottery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cognac","name":"Cognac","kind":"product","category":"drink","title":"How cognac is made","url":"https://assemblyline.org/make/cognac","stations":6,"upstream":43,"downstream":0,"depth":6,"dek":"The thin, sour wine behind cognac is described as nearly undrinkable, and that is what makes it good for distilling.","answer":"Cognac is brandy made from a very dry, acidic white wine, distilled twice in copper pot stills in the Cognac region of France and aged in oak for at least two years. A master blender then marries spirits of different ages. About 3 percent evaporates from every cask each year.","aka":["French brandy","eau-de-vie de Cognac"],"inputs":["grapes","wine-barrel","glass-bottle","water"],"uses":[],"grounds":["grapes","water","timber","silica-sand","limestone","rock-salt","trona","iron-ore","air","dolomite","manganese-ore","natural-gas","corn","coal","quartz","crude-oil","sulfur","sugarcane","sugar-beet"],"upstreamSlugs":["grapes","wine-barrel","glass-bottle","water","timber","steel","silica-sand","soda-ash","limestone","polyethylene","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","rock-salt","ammonia","carbon-dioxide","trona","ethylene","iron-ore","coke","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","corn","yeast","naphtha","coal","quartz","charcoal","crude-oil","sulfur","molasses","hydrogen","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Press the grapes","process":"press","text":"White grapes, mostly Ugni blanc, Folle blanche and Colombard, are pressed. The wine made from them is dry, acidic and thin, and well suited to distilling and aging.","inputs":["grapes"]},{"name":"Ferment with wild yeast","process":"ferment","text":"The juice ferments for two to three weeks using the region's native wild yeast. Neither sugar nor sulphur may be added, and the wine ends up 7 to 8 percent alcohol.","inputs":[],"spec":"2 to 3 weeks"},{"name":"Distill twice in copper","process":"refine","text":"The wine is distilled twice in Charentais copper alembic stills, whose design and size are controlled by law. The result is a colorless spirit of about 70 percent alcohol.","inputs":[]},{"name":"Age in Limousin oak","process":"dry","text":"The spirit rests in Limousin oak casks for at least two years before sale, at about 70 percent alcohol to start. It loses about 3 percent each year to evaporation, called the angels' share.","inputs":["wine-barrel"],"spec":"at least 2 years"},{"name":"Blend the ages","process":"mix","text":"A master taster combines spirits of different ages and sources to keep a house style consistent. The age on the label is that of the youngest spirit in the blend.","inputs":[]},{"name":"Bottle it","process":"fill","text":"The blend is brought to bottling strength and filled into glass bottles.","inputs":["glass-bottle","water"]}],"facts":["After more than fifty years in oak, cognac falls to 40 percent alcohol and is moved to large glass bottles called bonbonnes, because wood stops adding flavor after four or five decades.","Cognac houses buy from hundreds of vineyards that also sell their own bottlings."],"where":[],"whereNote":null,"sources":[{"title":"Cognac","url":"https://en.wikipedia.org/wiki/Cognac"},{"title":"Distillation","url":"https://en.wikipedia.org/wiki/Distillation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"coil-spring","name":"Coil spring","kind":"product","category":"hardware","title":"How coil springs are made","url":"https://assemblyline.org/make/coil-spring","stations":7,"upstream":62,"downstream":1,"depth":10,"dek":"Squeeze a coil spring and its wire twists along its length, which is where the push comes from.","answer":"A coil spring is spring-steel wire wound around a rotating mandrel into a helix. Small springs can be wound from wire that is already hard, while bigger ones are wound soft and hardened afterward. The ends are ground flat, and the finished spring is tested for the force it gives at a set length.","aka":["helical spring","compression spring"],"inputs":["steel-wire","paint"],"uses":["padlock"],"grounds":["water","titanium-ore","iron-ore","sulfur","limestone","air","dolomite","manganese-ore","natural-gas","rock-salt","coal","crude-oil","quartz","timber","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["steel-wire","paint","steel","water","titanium-dioxide","pigment","acrylic","tin-can","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","carbon-black","sulfur","propylene","ammonia","methanol","tinplate","lacquer","ink","limestone","air","dolomite","silicon","propane","manganese-ore","natural-gas","rock-salt","coal","crude-oil","naphtha","tin","ethanol","vegetable-oil","phenolic-resin","quartz","charcoal","timber","hydrogen","tin-ore","corn","sugarcane","yeast","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","molasses","benzene","sugar-beet","toluene"],"downstreamSlugs":["padlock"],"steps":[{"name":"Feed the wire","process":"draw","text":"Spring steel wire is pulled from a spool through straightening guides into the winding machine.","inputs":["steel-wire"]},{"name":"Wind the helix","process":"press","text":"The wire is fed against a pin that forces it to curl as it wraps around a rotating mandrel. The spacing between turns sets how stiff the spring is.","inputs":[]},{"name":"Heat treat the coil","process":"heat-treat","text":"Coils go straight onto a conveyor through an oven. Wire that was already hard only needs its winding stress relieved, so it keeps its shape and springs back. Springs wound from soft steel are hardened and then tempered.","inputs":[]},{"name":"Grind the ends flat","process":"grind","text":"A dish carries compression springs slowly between two horizontal wheels, which grind the last coils flat so they stand upright and push evenly.","inputs":[]},{"name":"Blast with steel shot","process":"machine","text":"Round shot is fired at the wire, leaving a skin of tiny dimples held in compression. That skin resists the cracks that end a spring's life.","inputs":[]},{"name":"Coat against rust","process":"coat","text":"Springs are plated, painted or coated in oil, depending on how they will be used.","inputs":["paint"]},{"name":"Test the force","process":"inspect","text":"Machines compress each batch sample to a set length and record how hard it pushes back.","inputs":[]}],"facts":["Coiled springs first appeared in the early 15th century, in door locks.","When you compress or stretch a coil spring, its wire twists, so the spring's stiffness depends on the shear modulus of the steel.","A freshly coiled spring needs a trip through an oven, because without that stress relief it would not hold the shape it springs back to."],"where":[],"whereNote":null,"sources":[{"title":"Coil spring","url":"https://en.wikipedia.org/wiki/Coil_spring"},{"title":"Spring (device)","url":"https://en.wikipedia.org/wiki/Spring_(device)"},{"title":"How Springs Are Made","url":"https://linquip.com/blog/?p=25063"},{"title":"Manufacturing method of suspension spring for car","url":"https://patents.google.com/patent/US6346157B1"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"coin","name":"Coin","kind":"product","category":"hardware","title":"How coins are made","url":"https://assemblyline.org/make/coin","stations":6,"upstream":16,"downstream":0,"depth":4,"dek":"A coin's rim is raised before it is ever struck, by rolling the blank through a narrowing groove.","answer":"Mints buy coils of alloyed strip and punch round blanks from them. The blanks are heated to soften them, cleaned, and rolled through an upsetting mill that raises a rim. A press then drives a die into each one inside a steel collar, which prints both faces and the edge in one blow.","aka":["money coin","minting"],"inputs":["copper","nickel","zinc","silver"],"uses":[],"grounds":["copper-ore","water","air","nickel-ore","zinc-ore","silver-ore","lead-ore","sulfur","limestone"],"upstreamSlugs":["copper","nickel","zinc","silver","copper-ore","water","oxygen","air","sulfuric-acid","nickel-ore","zinc-ore","silver-ore","lead-ore","lime","sulfur","limestone"],"downstreamSlugs":[],"steps":[{"name":"Roll the strip","process":"roll","text":"Metal is assayed, melted, cast into slabs and rolled to exact thickness. Clad coins bond copper-nickel layers to a copper core. The strip is coiled and shipped to the mint.","inputs":["copper","nickel","zinc","silver"]},{"name":"Punch out the blanks","process":"stamp","text":"A bank of punches drives through the strip into a bedplate with matching holes, cutting discs slightly larger than the finished coin. Screens drop out thin or broken pieces, which go back to be melted.","inputs":[]},{"name":"Soften and clean","process":"heat-treat","text":"Blanks pass through an annealing furnace and a water quench. Softer metal needs less striking force, which makes the dies last longer. Tumbling in a chemical bath removes discoloration, and hot air dries them.","inputs":[]},{"name":"Raise the rim","process":"roll","text":"An upsetting mill rolls each blank along a groove that keeps narrowing, which pushes metal up into a rim. The squeeze sizes the blank and work-hardens its edge.","inputs":[]},{"name":"Strike between the dies","process":"stamp","text":"A planchet drops into a hardened steel collar above the lower die, and the upper die comes down. Metal flows into every line of the engraving, and the collar forms the plain or reeded edge.","inputs":[]},{"name":"Inspect and count","process":"inspect","text":"The press operator spot-checks coins, and a sizing screen called a riddler removes any too large or too small. The rest are counted and bagged.","inputs":[]}],"facts":["Matthew Boulton installed eight steam-driven presses in 1788, each able to strike 70 to 84 coins per minute.","The Croeseid, issued by King Croesus of Lydia, are credited as the first true gold coins of standardized purity.","Some medieval coins, called bracteates, were so thin they were struck on only one side."],"where":[],"whereNote":null,"sources":[{"title":"Coin","url":"https://en.wikipedia.org/wiki/Coin"},{"title":"Mint (coin)","url":"https://en.wikipedia.org/wiki/Mint_(coin)"},{"title":"How is a coin made?: Collector Basics","url":"https://www.coinworld.com/news/us-coins/collector-basics-how-coins-are-made.html"},{"title":"How Modern Coins are Made","url":"https://blog.littletoncoin.com/modern-coins-are-made/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"coke","name":"Coke","kind":"material","category":"metals","title":"How coke is made","url":"https://assemblyline.org/make/coke","stations":5,"upstream":1,"downstream":333,"depth":1,"dek":"Coke is coal baked until only its hard, porous skeleton is left, and that skeleton holds a blast furnace open.","answer":"Coke is made by heating blended bituminous coal in sealed ovens with no air, at roughly 1,000 to 1,100 °C. Water, tar and gas boil out of the coal, leaving a hard, porous lump of nearly pure carbon. The glowing coke is quenched, then sorted by size so it can carry the weight of a furnace full of iron ore.","aka":["metallurgical coke","furnace coke","coking"],"inputs":["coal"],"uses":["titanium-dioxide","silicon","pig-iron","tin","lead","chromium","manganese","phosphoric-acid"],"grounds":["coal"],"upstreamSlugs":["coal"],"downstreamSlugs":["titanium-dioxide","silicon","pig-iron","tin","lead","chromium","manganese","phosphoric-acid","toothpaste","sunscreen","lipstick","nail-polish","ink","paint","crayon","pencil-eraser","candy-coated-chocolate","foundation-makeup","pvc-pipe","e-reader","pigment","silicone","polysilicon","magnesium","trichlorosilane","steel","cast-iron-pan","car-engine","piano","dumbbell","sailboat","microchip","tinplate","brass","bronze","solder","padlock","window-glass","indium-tin-oxide","medal","bell","usb-cable","chess-set","stained-glass","car-battery","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","stent","wrench","nichrome","leather","thermometer","lithium-ion-cell","aa-battery","cola","soda","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","scissors","mirror","car","electric-car","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toothbrush","mascara","pvc","abs-plastic","lego-brick","lcd-screen","porcelain","chalk","candy-cane","sprinkles","plastic-straw","printer-toner","eyeshadow","towel","shampoo","deodorant","condom","hearing-aid","solar-panel","contact-lens","airbag","cork-stopper","pressure-cooker","blender","prosthetic-leg","double-glazed-window","remote-control","electric-toothbrush","silicon-wafer","titanium","digital-camera","ev-battery","television","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","steel-wire","rebar","steel-beam","rail","steel-pipe","ball-bearing","elevator","drum-kit","wine-barrel","dishwasher","office-chair","yo-yo","harmonica","saxophone","dental-floss","wheelchair","barbed-wire","drill-bit","spark-plug","seat-belt","suitcase","high-heels","loudspeaker","pacemaker","smartphone","laptop","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","rocket","smartwatch","wireless-earbuds","phone-charger","game-console","wifi-router","graphics-card","canned-tuna","air-freshener","hairspray","tire","electric-guitar","trumpet","fountain-pen","garden-hose","guitar-string","hinge","key","light-switch","power-outlet","handbag","zipper","bronze-statue","printed-circuit-board","led-bulb","air-conditioner","flute","smoke-detector","microphone","skyscraper","oled-screen","kitchen-knife","fork","thermos","asthma-inhaler","jet-engine","football","winter-gloves","wallet","hiking-boots","leather-shoe","cotton-candy","pillow","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sparkling-water","beer","hard-cider","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","soap","detergent","nitrile-glove","paperclip","donut","corn-flakes","popcorn","fireworks","candle","salsa","fish-sticks","zip-bag","cotton-swab","mouthwash","cough-syrup","facial-tissue","envelope","plastic-wrap","volleyball","yoga-mat","inflatable-pool-toy","chain-link-fence","power-cable","3d-printer-filament","headphones","champagne","memory-chip","camera-sensor","solar-cell","treadmill","saw-blade","shovel","wire-rope","nail","screw","needle","guitar","violin","clothespin","staple","sofa","slinky","cello","bolt","chain","mattress","concrete","roller-skates","wine","bourbon","scotch","cognac","port-wine","down-jacket","raincoat","backpack","jeans","pinball-machine","toffee"],"steps":[{"name":"Blend the coals","process":"mix","text":"Coke plants do not bake one coal. They mix several bituminous coals until the blend gives off the right amount of gas as it cooks, because that decides how strong the finished lumps will be. A volatile content of 26 to 29 percent is considered good for the job.","inputs":["coal"]},{"name":"Seal it in an oven","process":"fill","text":"The blended coal is loaded into a chamber of firebrick and shut off from the air. In the old beehive ovens, a dome about 4 meters wide, the coal lay in a layer 60 to 90 centimeters deep. Ovens are built in rows, called batteries, with walls shared between them.","inputs":[]},{"name":"Bake out the volatiles","process":"bake","text":"With no air to burn it, the coal cannot catch fire. It just cooks, and water, coal gas and tar are driven out as vapor. The cooking front creeps through the charge from the outside in, and a beehive oven needed two to three days to finish.","inputs":[],"spec":"1,000 to 1,100 °C"},{"name":"Quench the red-hot cake","process":"chill","text":"The glowing coke is pushed out and cooled, usually with a water spray or by air. Water-quenched coke soaks up 3 to 6 percent of its mass in water in its pores.","inputs":[]},{"name":"Screen and sort the lumps","process":"separate","text":"Lump size matters. A blast furnace is a tall stack of ore and fuel, and gas has to rise through it, so the coke must be strong enough not to crush under the load. Strength is checked with crush tests before it goes to the furnace.","inputs":[]}],"facts":["Abraham Darby set up a coke-fired blast furnace in 1709, and coke's crushing strength let furnaces grow much taller than charcoal ones.","Baking coal drives off coal gas and coal tar, and the byproducts also include coal-tar pitch, ammonia and pyridine.","By 1870 there were 14,000 beehive ovens in the West Durham coalfields alone, making 4,000,000 long tons of coke per year."],"where":[],"whereNote":null,"sources":[{"title":"Coke (fuel)","url":"https://en.wikipedia.org/wiki/Coke_(fuel)"},{"title":"Blast furnace","url":"https://en.wikipedia.org/wiki/Blast_furnace"},{"title":"Coking coal","url":"https://en.wikipedia.org/wiki/Coking_coal"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cola","name":"Cola","kind":"product","category":"drink","title":"How cola is made","url":"https://assemblyline.org/make/cola","stations":7,"upstream":70,"downstream":0,"depth":9,"dek":"A cola company sells only a syrup concentrate, and local bottlers add the water, sweetener and bubbles.","answer":"Cola is built from a flavored syrup. Sugar or another sweetener, caramel color, phosphoric acid and a blend of citrus oils, cinnamon, vanilla and other flavors make a concentrate. At a bottling plant it is diluted with filtered water, charged with carbon dioxide under pressure, and sealed into cans or bottles.","aka":["cola soda","cola drink","coke"],"inputs":["oranges","vanilla-extract","caramel-color","phosphoric-acid","sugar","corn-syrup","water","carbon-dioxide","aluminum-can","plastic-bottle","glass-bottle"],"uses":[],"grounds":["oranges","water","vanilla-pods","phosphate-rock","silica-sand","sugarcane","sugar-beet","corn","natural-gas","limestone","barley","air","sulfur","coal","crude-oil","rock-salt","trona","bauxite","soybeans","rapeseed","clay","titanium-ore","iron-ore"],"upstreamSlugs":["oranges","vanilla-extract","caramel-color","phosphoric-acid","sugar","corn-syrup","water","carbon-dioxide","aluminum-can","plastic-bottle","glass-bottle","vanilla-pods","ethanol","molasses","malted-barley","ammonia","phosphate-rock","sulfuric-acid","coke","silica-sand","sugarcane","sugar-beet","lime","corn","corn-starch","natural-gas","yeast","limestone","aluminum","ink","epoxy","pet-plastic","soda-ash","polyethylene","ethylene","barley","air","sulfur","coal","crude-oil","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","phenol","propylene","acetone","chlorine","caustic-soda","p-xylene","ethylene-glycol","rock-salt","trona","naphtha","bauxite","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","oxygen","iron-ore","benzene","hydrogen","methanol","toluene"],"downstreamSlugs":[],"steps":[{"name":"Blend the flavor oils","process":"mix","text":"Citrus oils from orange, lime and lemon peel are combined with cinnamon, vanilla and trace flavorings. The exact proportions are a corporate trade secret.","inputs":["oranges","vanilla-extract"]},{"name":"Tint it brown","process":"cook","text":"Caramel color is made by heating sugars, often with acids, alkalis or salts. It is more fully cooked than caramel candy and gives cola its dark brown shade.","inputs":["caramel-color"]},{"name":"Add the acid","process":"mix","text":"Phosphoric acid gives cola its tang. Food-grade acid is made from phosphate rock, and it also helps preserve the syrup.","inputs":["phosphoric-acid"]},{"name":"Sweeten into syrup","process":"mix","text":"Sugar, high-fructose corn syrup or an artificial sweetener goes in, depending on region and cost. In the US corn syrup has long been the main choice, while Europe leans toward sugar.","inputs":["sugar","corn-syrup"]},{"name":"Dilute the concentrate","process":"mix","text":"At a bottling plant, the concentrate from the cola company is diluted with filtered water. Syrup and water are typically mixed at about one part syrup to five parts water.","inputs":["water"],"spec":"about 1:5"},{"name":"Charge with gas","process":"mix","text":"Chilled water takes up the most carbon dioxide, so carbonation happens cold and under high pressure. Colas are carbonated to around 3.5 volumes of gas per volume of liquid. Food-grade carbon dioxide often comes from ammonia plants.","inputs":["carbon-dioxide"],"spec":"3.5 volumes of CO2"},{"name":"Fill and seal fast","process":"fill","text":"Cans and bottles are filled and capped quickly so the bubbles stay dissolved. Pressure inside the container keeps the gas in solution until you open it.","inputs":["aluminum-can","plastic-bottle","glass-bottle"]}],"facts":["The kola nut contains about 2.0 to 3.5% caffeine and gave the original recipe its name.","In the 1940s Coca-Cola made a clear version called White Coke at the request of Soviet marshal Georgy Zhukov."],"where":[],"whereNote":null,"sources":[{"title":"Cola","url":"https://en.wikipedia.org/wiki/Cola"},{"title":"Soft drink","url":"https://en.wikipedia.org/wiki/Soft_drink"},{"title":"Caramel color","url":"https://en.wikipedia.org/wiki/Caramel_color"},{"title":"Phosphoric acid","url":"https://en.wikipedia.org/wiki/Phosphoric_acid"},{"title":"Coca-Cola","url":"https://en.wikipedia.org/wiki/Coca-Cola"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"compact-disc","name":"Compact disc","kind":"product","category":"electronics","title":"How compact discs are made","url":"https://assemblyline.org/make/compact-disc","stations":6,"upstream":60,"downstream":0,"depth":8,"dek":"Each pit on a compact disc is about 100 nanometers deep, and a laser reads them from underneath.","answer":"A compact disc is a disc of clear polycarbonate plastic molded with a spiral track of tiny pits. A thin layer of aluminum is deposited over the pits in a vacuum to make them reflective, then a layer of lacquer protects the metal. The label is printed on top. A laser reads the pits from underneath.","aka":["CD","audio CD","CD-ROM"],"inputs":["photoresist","nickel","polycarbonate","aluminum","lacquer","ink","polystyrene","paper"],"uses":[],"grounds":["nickel-ore","crude-oil","coal","water","kaolin","limestone","sulfur","air","rock-salt","bauxite","corn","sugarcane","soybeans","rapeseed","clay","titanium-ore","iron-ore","natural-gas","timber","sugar-beet"],"upstreamSlugs":["photoresist","nickel","polycarbonate","aluminum","lacquer","ink","polystyrene","paper","phenolic-resin","nickel-ore","sulfuric-acid","phenol","propylene","acetone","caustic-soda","chlorine","crude-oil","coal","petroleum-coke","alumina","ethanol","acrylic","vegetable-oil","carbon-black","titanium-dioxide","pigment","water","naphtha","ethylene","benzene","styrene","wood-pulp","kaolin","limestone","formaldehyde","sulfur","air","rock-salt","bauxite","lime","corn","sugarcane","yeast","ammonia","methanol","soybeans","rapeseed","hexane","clay","titanium-ore","coke","oxygen","iron-ore","hydrogen","natural-gas","toluene","timber","hydrogen-peroxide","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Master the pit pattern","process":"etch","text":"The audio data is encoded and written as a spiral of tiny pits onto a master disc. The master is used to make a metal stamper, the negative of the pit pattern.","inputs":["photoresist","nickel"]},{"name":"Mold the plastic disc","process":"mold","text":"Molten polycarbonate is injected against the stamper in a clean mold. The plastic hardens in seconds with the pattern of pits pressed into one face, so the stamper can be used again for the next disc.","inputs":["polycarbonate"]},{"name":"Metalize the surface","process":"deposit","text":"A thin layer of aluminum, or rarely gold, is deposited over the pits in a vacuum chamber. The metal fills the surface so that light is reflected differently from pits and flat areas.","inputs":["aluminum"]},{"name":"Spin on the lacquer","process":"coat","text":"The disc is spun to spread a thin film of lacquer over the metal. The lacquer protects the aluminum, since the reflective layer is on the label side and is only a hair from the surface.","inputs":["lacquer"]},{"name":"Print the label","process":"print","text":"The label is printed on the lacquer by screen or offset printing. The disc is checked on a player that reads the track as it spins.","inputs":["ink"]},{"name":"Package the disc","process":"package","text":"Discs are tested, then dropped into plastic cases with printed inserts and wrapped.","inputs":["polystyrene","paper"]}],"facts":["Each pit on a CD is about 100 nm deep and 500 nm wide.","A CD player reads the track with a 780 nm infrared laser focused through the plastic from underneath."],"where":[],"whereNote":null,"sources":[{"title":"Compact disc","url":"https://en.wikipedia.org/wiki/Compact_disc"},{"title":"Injection moulding","url":"https://en.wikipedia.org/wiki/Injection_moulding"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"computer-keyboard","name":"Computer keyboard","kind":"product","category":"electronics","title":"How computer keyboards are made","url":"https://assemblyline.org/make/computer-keyboard","stations":6,"upstream":77,"downstream":1,"depth":9,"dek":"Under the keys of a typical keyboard are plastic sheets printed with conductive traces, produced by reel-to-reel printing.","answer":"Keycaps are injection molded from plastic. Under them, a rubber dome or scissor mechanism sits above a stack of plastic membrane sheets printed with conductive traces, or above a circuit board with individual switches. A small controller scans the key matrix and reports which keys were pressed.","aka":["keyboard","PC keyboard","mechanical keyboard"],"inputs":["abs-plastic","rubber","printed-circuit-board","microchip"],"uses":["laptop"],"grounds":["air","natural-latex","sulfur","crude-oil","water","natural-gas","iron-ore","copper-ore","silica-sand","limestone","quartz","tin-ore","coal","gold-ore","titanium-ore","rock-salt","trona","lead-ore","silver-ore","zinc-ore","bauxite","corn","timber","sugarcane","sugar-beet"],"upstreamSlugs":["abs-plastic","rubber","printed-circuit-board","microchip","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","natural-latex","synthetic-rubber","carbon-black","sulfur","copper","fiberglass","epoxy","photoresist","solder","silicon-wafer","oxygen","tin","aluminum","gold","crude-oil","water","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","copper-ore","sulfuric-acid","silica-sand","limestone","soda-ash","phenol","acetone","chlorine","caustic-soda","phenolic-resin","lead","silver","polysilicon","quartz","argon","tin-ore","coke","coal","petroleum-coke","alumina","gold-ore","lime","zinc","titanium-ore","rock-salt","carbon-dioxide","trona","formaldehyde","lead-ore","silver-ore","zinc-ore","silicon","hydrochloric-acid","trichlorosilane","nitrogen","bauxite","corn","yeast","methanol","charcoal","timber","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["laptop"],"steps":[{"name":"Mold the keycaps","process":"mold","text":"Molten plastic fills steel molds, one cavity per keycap. Legends are printed or lasered on afterward.","inputs":["abs-plastic"]},{"name":"Print the membrane sheets","process":"print","text":"Conductive traces are printed on plastic sheets by reel-to-reel machines. The sheets are cut and punched afterward.","inputs":[]},{"name":"Stack the switch layers","process":"laminate","text":"Two printed sheets are stacked with a spacer between them. When a key presses them together, the contacts touch and complete a circuit.","inputs":[]},{"name":"Add domes or springs","process":"assemble","text":"Rubber domes or scissor mechanisms, or separate mechanical switches, go above each switch position to give the key its feel.","inputs":["rubber"]},{"name":"Wire the controller","process":"assemble","text":"A small circuit board scans the grid of keys. It sends the computer a scan code that tells it which physical key was pressed or released.","inputs":["printed-circuit-board","microchip"]},{"name":"Fit caps and test","process":"inspect","text":"Caps are pressed on, and every key is checked for a clean signal.","inputs":[]}],"facts":["Key Tronic's 1978 capacitive keyboard used a sponge pad with a conductive-coated Mylar sheet, and the company rapidly became the largest independent keyboard maker.","Standard ANSI keys sit on three-quarter inch spacing."],"where":[],"whereNote":null,"sources":[{"title":"Computer keyboard","url":"https://en.wikipedia.org/wiki/Computer_keyboard"},{"title":"Capacitive sensing","url":"https://en.wikipedia.org/wiki/Capacitive_sensing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"computer-mouse","name":"Computer mouse","kind":"product","category":"electronics","title":"How computer mice are made","url":"https://assemblyline.org/make/computer-mouse","stations":5,"upstream":79,"downstream":0,"depth":9,"dek":"An optical mouse is a tiny camera that photographs the desk surface over and over and tracks how the picture shifts.","answer":"A computer mouse is a molded plastic shell around a small circuit board. An LED or laser lights the surface, and an optical sensor on the board takes successive pictures of it. A chip compares them to work out movement. Buttons, a scroll wheel and a cable or wireless radio finish it.","aka":["mouse","optical mouse","wireless mouse","laser mouse"],"inputs":["abs-plastic","printed-circuit-board","microchip","led","copper-wire"],"uses":[],"grounds":["air","crude-oil","water","natural-gas","iron-ore","sulfur","copper-ore","silica-sand","limestone","quartz","tin-ore","coal","gold-ore","bauxite","zinc-ore","titanium-ore","rock-salt","trona","lead-ore","silver-ore","corn","timber","sugarcane","sugar-beet"],"upstreamSlugs":["abs-plastic","printed-circuit-board","microchip","led","copper-wire","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","copper","fiberglass","epoxy","photoresist","solder","silicon-wafer","oxygen","tin","aluminum","gold","gallium","indium","hydrogen","plastic","crude-oil","water","natural-gas","toluene","iron-ore","titanium-dioxide","carbon-black","sulfur","copper-ore","sulfuric-acid","silica-sand","limestone","soda-ash","phenol","acetone","chlorine","caustic-soda","phenolic-resin","lead","silver","polysilicon","quartz","argon","tin-ore","coke","coal","petroleum-coke","alumina","gold-ore","lime","zinc","bauxite","zinc-ore","titanium-ore","rock-salt","carbon-dioxide","trona","formaldehyde","lead-ore","silver-ore","silicon","hydrochloric-acid","trichlorosilane","nitrogen","corn","yeast","methanol","charcoal","timber","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the shell","process":"mold","text":"Top and bottom shells are injection molded in plastic, along with the button covers.","inputs":["abs-plastic"]},{"name":"Assemble the sensor board","process":"assemble","text":"An LED or laser diode and an imaging sensor go onto a small board with a processor. The sensor is essentially a low-resolution video camera.","inputs":["printed-circuit-board","microchip","led"]},{"name":"Fit buttons and wheel","process":"assemble","text":"Micro switches under each button and an encoder under the scroll wheel are soldered or snapped in.","inputs":[]},{"name":"Connect cable or radio","process":"assemble","text":"A cord is attached, or a wireless chip and battery are fitted. Battery-powered optical mice flash their LED intermittently to save power and glow steadily only while moving.","inputs":["copper-wire"]},{"name":"Close and test","process":"inspect","text":"The shell is screwed shut, and each mouse is moved across a test surface to confirm tracking and clicks.","inputs":[]}],"facts":["The Xerox 8010 Star of 1981 was the third marketed computer to ship with an integrated mouse.","Richard F. Lyon demonstrated a low-resolution imager with in-pixel amplification for an optical mouse in 1981.","Most optical mice cannot track on polished stone because it is too smooth and shiny to reveal texture."],"where":[],"whereNote":null,"sources":[{"title":"Computer mouse","url":"https://en.wikipedia.org/wiki/Computer_mouse"},{"title":"Active-pixel sensor","url":"https://en.wikipedia.org/wiki/Active-pixel_sensor"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"concrete","name":"Concrete","kind":"material","category":"minerals","title":"How concrete is made","url":"https://assemblyline.org/make/concrete","stations":6,"upstream":44,"downstream":1,"depth":8,"dek":"Concrete is the second most-used substance on Earth after water, and it hardens by a chemical reaction, not by drying out.","answer":"Concrete is cement, water, sand and crushed stone mixed into a pourable slurry. The cement reacts with the water in a process called hydration, which hardens the mix into stone over several hours. Steel rebar is usually cast in, because concrete is strong when squeezed but weak when stretched.","aka":["Portland cement concrete","ready-mix concrete"],"inputs":["gravel","silica-sand","cement","water","rebar"],"uses":["skyscraper"],"grounds":["gravel","silica-sand","water","limestone","clay","gypsum","zinc-ore","air","iron-ore","dolomite","manganese-ore","natural-gas","crude-oil","sulfur","rock-salt","coal","quartz","timber"],"upstreamSlugs":["gravel","silica-sand","cement","water","rebar","limestone","clay","gypsum","steel","steel-scrap","zinc","epoxy","pig-iron","magnesium","oxygen","lime","manganese","argon","propane","zinc-ore","air","sulfuric-acid","phenol","propylene","acetone","chlorine","caustic-soda","iron-ore","coke","dolomite","silicon","manganese-ore","natural-gas","crude-oil","sulfur","benzene","naphtha","rock-salt","coal","quartz","charcoal","timber","hydrogen","toluene"],"downstreamSlugs":["skyscraper"],"steps":[{"name":"Quarry sand and stone","process":"mine","text":"Aggregate is the bulk of any mix. Sand, natural gravel and crushed stone such as limestone or granite are used, and recycled demolition rubble increasingly stands in for part of it.","inputs":["gravel","silica-sand"]},{"name":"Weigh every ingredient","process":"mix","text":"At a batching plant, hoppers feed aggregate, cement and water to scales that weigh each ingredient precisely. Less water gives stronger, more durable concrete, and more water makes it flow more freely.","inputs":["cement","water"]},{"name":"Add the admixtures","process":"mix","text":"Small doses of additives tune the mix. Plasticizers let it flow with less water, retarders slow hydration on hot days or big pours, and accelerators speed it up. Fly ash or blast furnace slag can replace part of the cement.","inputs":[]},{"name":"Keep it turning on the truck","process":"mix","text":"Once the ingredients are combined, workers must place the concrete before it hardens, so mixer trucks keep it moving on the road. Hydration begins as soon as water meets cement.","inputs":[]},{"name":"Pour it around the steel","process":"cast","text":"The wet mix is poured into forms around a cage of steel rebar. Concrete can be formulated for very high compressive strength, but its tensile strength is always lower, so the steel carries the stretching loads.","inputs":["rebar"]},{"name":"Let it cure","process":"dry","text":"Hydration is irreversible. The cement dissolves into the water, and interlocking crystals grow through the mix and bind it into one mass. Strength keeps building for weeks.","inputs":[]}],"facts":["Roman concrete, made with volcanic ash, had a compressive strength similar to modern Portland-cement concrete, around 20 MPa.","Smeaton's Tower, the third Eddystone Lighthouse, built between 1756 and 1759, pioneered the use of hydraulic lime in concrete.","Cement makes up only about 15% of concrete, yet it is the most energy-hungry ingredient."],"where":[],"whereNote":null,"sources":[{"title":"Concrete","url":"https://en.wikipedia.org/wiki/Concrete"},{"title":"Portland cement","url":"https://en.wikipedia.org/wiki/Portland_cement"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"condensed-milk","name":"Condensed milk","kind":"product","category":"food","title":"How condensed milk is made","url":"https://assemblyline.org/make/condensed-milk","stations":6,"upstream":62,"downstream":1,"depth":9,"dek":"Sweetened condensed milk lasts for years unopened because so much sugar leaves microbes with nothing to drink.","answer":"Milk is cleaned, standardized and heated, then a vacuum pan boils off roughly 60 percent of its water. Sugar is dissolved into the thick liquid until the sugar-to-milk ratio hits 9 to 11. Sugar's pull on water starves microbes, so the cooled, seeded milk keeps for years in a sealed can.","aka":["sweetened condensed milk"],"inputs":["raw-milk","sugar","tin-can"],"uses":["toffee"],"grounds":["raw-milk","sugarcane","sugar-beet","water","limestone","tin-ore","corn","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","dolomite","manganese-ore","natural-gas","coal","rock-salt","quartz","timber"],"upstreamSlugs":["raw-milk","sugar","tin-can","sugarcane","sugar-beet","water","lime","tinplate","lacquer","ink","limestone","steel","tin","ethanol","acrylic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","pig-iron","magnesium","steel-scrap","oxygen","manganese","argon","tin-ore","coke","corn","yeast","ethylene","propylene","ammonia","sulfuric-acid","methanol","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","iron-ore","sulfur","dolomite","silicon","propane","manganese-ore","natural-gas","coal","molasses","naphtha","hydrogen","benzene","rock-salt","quartz","charcoal","timber","toluene"],"downstreamSlugs":["toffee"],"steps":[{"name":"Clean and standardize the milk","process":"separate","text":"Raw milk is clarified and its fat is adjusted against the other milk solids, so every batch has the same recipe.","inputs":["raw-milk"]},{"name":"Hold it hot for seconds","process":"pasteurize","text":"A short blast of heat destroys some microorganisms, cuts down fat separation and slows oxidation.","inputs":[],"spec":"85 to 90 °C"},{"name":"Boil off the water","process":"refine","text":"Water is evaporated under vacuum, which lets milk reduce without scorching or curdling. Roughly 60 percent of the water leaves.","inputs":[]},{"name":"Dissolve in the sugar","process":"mix","text":"Sugar is added until it reaches a ratio of 9 parts sugar to 11 parts evaporated milk. The sugar raises the osmotic pressure of the liquid, which stops microorganisms from growing.","inputs":["sugar"],"spec":"9:11 sugar to milk"},{"name":"Cool and seed crystals","process":"chill","text":"The sweetened milk is cooled and lactose crystallization is deliberately triggered. This keeps the lactose crystals tiny, so the finished product feels smooth and not gritty.","inputs":[]},{"name":"Seal it in cans","process":"fill","text":"The thick milk is filled into cans and sealed. Unopened, sweetened condensed milk can last for years without refrigeration.","inputs":["tin-can"]}],"facts":["Gail Borden got the idea for his vacuum pan from Shakers who used one to condense fruit juice.","The Union Army ordered huge amounts of condensed milk, and a 10-ounce can held about 1,300 calories.","Borden demanded that farmers wash cows' udders and scald their strainers, rules that mattered as much as the pan."],"where":[],"whereNote":null,"sources":[{"title":"Condensed milk","url":"https://en.wikipedia.org/wiki/Condensed_milk"},{"title":"Powdered milk","url":"https://en.wikipedia.org/wiki/Powdered_milk"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"condom","name":"Condom","kind":"product","category":"body-health","title":"How condoms are made","url":"https://assemblyline.org/make/condom","stations":9,"upstream":28,"downstream":0,"depth":5,"dek":"Latex condoms are made by dipping glass or ceramic forms into liquid rubber, like candles in reverse.","answer":"A continuous chain of glass formers, each shaped like the finished product, runs through tanks of compounded latex. The film is dried and dipped again, a rim is rolled at the open end, and an oven vulcanizes the rubber. Water jets strip the condoms off, and every one is then stretched over a metal former and tested with high voltage.","aka":["male condom","rubber","prophylactic"],"inputs":["natural-latex","water","silicone","aluminum-foil"],"uses":[],"grounds":["natural-latex","water","silica-sand","quartz","coal","timber","natural-gas","crude-oil","rock-salt","bauxite","sulfur","air","limestone"],"upstreamSlugs":["natural-latex","water","silicone","aluminum-foil","silicon","methanol","hydrochloric-acid","silica-sand","aluminum","quartz","coke","coal","charcoal","timber","natural-gas","chlorine","hydrogen","crude-oil","petroleum-coke","alumina","rock-salt","sulfuric-acid","bauxite","caustic-soda","lime","sulfur","air","limestone"],"downstreamSlugs":[],"steps":[{"name":"Compound the latex","process":"mix","text":"Liquid latex goes into mixing tanks with water, stabilizers, preservatives and vulcanizing chemicals, each ground evenly first. One maker holds the blend at 54 °C for 12 to 13 hours, then moves it to supply tanks at 18 to 20 °C.","inputs":["natural-latex","water"]},{"name":"Dip the glass formers","process":"coat","text":"Clean glass formers ride a continuous chain, often in double rows, down into a temperature-controlled tank. They rotate as they come up so the thin film spreads evenly. Ribbed or studded formers give textured styles.","inputs":[]},{"name":"Dry and dip again","process":"coat","text":"Each film dries in an oven, cools, and goes back for another dip, which builds up the wall. Factories differ on the count: one describes two dips, another three.","inputs":[],"spec":"0.06-0.08 mm wall"},{"name":"Roll the rim","process":"mold","text":"At a beading station the open end of the film rolls up on itself into the ring that makes the product easy to put on.","inputs":[]},{"name":"Vulcanize in the oven","process":"heat-treat","text":"The formers pass through an oven at about 100 to 120 °C. Heat finishes the reaction between rubber and curing chemicals, and that reaction gives the film its strength and stretch.","inputs":[]},{"name":"Strip and wash","process":"wash","text":"Water jets push the film off the glass. Washing takes away water-soluble residue, and a safe powder stops the condoms from sticking to one another.","inputs":["water"]},{"name":"Test each one electronically","process":"inspect","text":"Each condom is stretched over a metal former and put under high voltage. A flaw too small to see lets current through and the machine rejects that piece. One maker checks the test machines themselves every half hour.","inputs":[]},{"name":"Burst and leak test samples","process":"inspect","text":"Samples from each batch are inflated with air, typically taking 40 liters before they burst, and others are filled with 300 ml of water and hung for a minute to look for leaks.","inputs":[]},{"name":"Seal in foil","process":"fill","text":"Passed condoms are lubricated, inspected once more as they are packed, and sealed in foil, then stored somewhere cool and dry until shipping.","inputs":["silicone","aluminum-foil"]}],"facts":["Modern condoms are most often made from latex, but some are made from polyurethane or lamb's intestine.","Modeling suggests that increased condom use since 1990 has averted approximately 117 million new HIV infections."],"where":[],"whereNote":null,"sources":[{"title":"Unity Condoms: how our condoms are made and tested","url":"https://mail.unitycondoms.eu.com/products/technology/index.html"},{"title":"Mango Condoms: condom manufacturing steps","url":"https://www.mangocondoms.com/?p=10831"},{"title":"Romo Condom: how a condom is produced in a factory","url":"https://romocondom.com/how-is-condoms-produced-by-condom-factories"},{"title":"WHO fact sheet: Condoms","url":"https://www.who.int/news-room/fact-sheets/detail/condoms"},{"title":"Birth control","url":"https://en.wikipedia.org/wiki/Contraceptive_device"},{"title":"Latex","url":"https://en.wikipedia.org/wiki/Latex"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"contact-lens","name":"Contact lens","kind":"product","category":"minerals","title":"How contact lenses are made","url":"https://assemblyline.org/make/contact-lens","stations":6,"upstream":18,"downstream":0,"depth":5,"dek":"A soft lens is molded around a stand-in liquid, and water takes its place later so the lens swells predictably.","answer":"Most soft lenses are cast. A liquid mix of water-loving monomers and an inert diluent is confined between two mold halves whose surfaces control the lens shape, then cured into a solid. The halves separate, the diluent is replaced with water so the lens swells to size, and it is inspected and packaged.","aka":["contacts","soft contact lens","hydrogel lens"],"inputs":["silicone","water"],"uses":[],"grounds":["water","silica-sand","quartz","coal","timber","natural-gas","rock-salt","sulfur","air"],"upstreamSlugs":["silicone","water","silicon","methanol","hydrochloric-acid","silica-sand","quartz","coke","coal","charcoal","timber","natural-gas","chlorine","hydrogen","rock-salt","sulfuric-acid","sulfur","air"],"downstreamSlugs":[],"steps":[{"name":"Mix the monomers","process":"mix","text":"Hydrophilic monomers are blended with an inert diluent and a catalyst. Replacing that diluent with water later keeps the lens from swelling unpredictably, a problem with older methods.","inputs":["silicone"]},{"name":"Fill the mold halves","process":"mold","text":"A small dose of liquid is trapped between two mold halves whose surfaces set both optical faces.","inputs":[]},{"name":"Cure into a lens","process":"react","text":"The monomer polymerizes in the mold and turns into a solid lens shape. Older routes use a spinning mold, or cut a dry button on a lathe and polish it.","inputs":[]},{"name":"Open the mold","process":"separate","text":"The halves are separated, leaving the lens ready for its soak.","inputs":[]},{"name":"Hydrate in water","process":"wash","text":"Water replaces the diluent and the lens swells into its soft gel. Makers call this step time consuming and difficult to control, so much patent work has gone into it.","inputs":["water"]},{"name":"Inspect and package","process":"inspect","text":"Each wet lens is inspected for flaws and sealed into its final package.","inputs":[]}],"facts":["Contact lenses were used by over 150 million people worldwide in 2012.","Leonardo da Vinci's 1508 notes described a water-filled glass hemisphere worn over the eye, but he did not propose it as a way to correct vision.","Cosmetic lenses that change eye color accounted for only 3% of contact lens fits in 2004."],"where":[],"whereNote":null,"sources":[{"title":"US5080839A: Process for hydrating soft contact lenses","url":"https://patents.google.com/patent/US5080839"},{"title":"US4680336A: Method of forming shaped hydrogel articles","url":"https://patents.google.com/patent/US4680336"},{"title":"Contact lens","url":"https://en.wikipedia.org/wiki/Contact_lens"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"container-ship","name":"Container ship","kind":"product","category":"machines","title":"How container ships are made","url":"https://assemblyline.org/make/container-ship","stations":9,"upstream":68,"downstream":0,"depth":10,"dek":"A container ship is welded together from prefabricated blocks and lifted into a dock like a giant kit.","answer":"A container ship is built in blocks. Steel plate is cut, welded into flat panels and then into multi-deck hull sections, with pipes and cables already installed. A crane lifts each block into a dry dock, where they are welded into a single hull. The engine, propeller and cargo guide rails go in before the ship floats out.","aka":["containership","box ship","cargo ship"],"inputs":["steel","steel-pipe","copper-wire","paint"],"uses":[],"grounds":["water","iron-ore","limestone","air","dolomite","manganese-ore","natural-gas","zinc-ore","copper-ore","titanium-ore","sulfur","coal","quartz","timber","crude-oil","rock-salt","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["steel","steel-pipe","copper-wire","paint","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","sheet-steel","zinc","copper","water","titanium-dioxide","pigment","acrylic","tin-can","iron-ore","coke","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","zinc-ore","copper-ore","titanium-ore","chlorine","carbon-black","sulfur","propylene","ammonia","methanol","tinplate","lacquer","ink","coal","quartz","charcoal","timber","crude-oil","rock-salt","naphtha","tin","ethanol","vegetable-oil","phenolic-resin","hydrogen","tin-ore","corn","sugarcane","yeast","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","molasses","benzene","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Cut the steel plates","process":"cut","text":"Steel plates are marked and cut to the shapes of frames, decks and hull skin. The ship's frames run at right angles to its keel, and the deck beams rest on top of them.","inputs":["steel"]},{"name":"Weld flat panels","process":"weld","text":"Plates are welded into large flat panels, which are the walls and floors of the future hull. Modern yards also use deep-penetration welding that fuses thick plate in a single pass.","inputs":[]},{"name":"Build the hull blocks","process":"assemble","text":"Panels are joined into whole sections of hull, several decks high. The most modern shipyards pre-install pipes, cables and equipment inside each block, so that little work is left deep inside the finished hull.","inputs":["steel-pipe","copper-wire"]},{"name":"Lift blocks into the dock","process":"assemble","text":"Cranes carry each block to the dry dock or slipway and set it in place against its neighbors. This is called block construction.","inputs":[]},{"name":"Weld the hull into one","process":"weld","text":"The seams between blocks are welded, turning dozens of sections into a single watertight shape.","inputs":[]},{"name":"Fit the cargo guides","process":"assemble","text":"The hull is like a vast warehouse divided into cells by vertical guide rails. Containers slide down between the rails and stay put in a swell.","inputs":["steel"]},{"name":"Paint below the waterline","process":"coat","text":"Hull plates are blasted, primed and covered in coats of paint that keep out seawater and slow the growth of marine organisms.","inputs":["paint"]},{"name":"Install engine and propeller","process":"assemble","text":"A very large slow-turning diesel engine is lowered into the engine room and linked to a single large propeller.","inputs":[]},{"name":"Float out and sea-trial","process":"inspect","text":"The dock is flooded and the ship floats free. It is then sailed on trials to check speed, steering and fuel use before the owner takes delivery.","inputs":[]}],"facts":["A ship delivered to MSC in 2023 holds 24,346 TEU, and measures 399.99 meters long and 61.3 meters across.","About 90 percent of the world's non-bulk cargo moves in containers.","In the years 2011 to 2013, an average of 2,683 containers a year were reported lost at sea."],"where":[],"whereNote":null,"sources":[{"title":"Container ship","url":"https://en.wikipedia.org/wiki/Container_ship"},{"title":"Shipbuilding","url":"https://en.wikipedia.org/wiki/Shipbuilding"},{"title":"Intermodal container","url":"https://en.wikipedia.org/wiki/Intermodal_container"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"copper","name":"Copper","kind":"material","category":"metals","title":"How copper is made","url":"https://assemblyline.org/make/copper","stations":6,"upstream":6,"downstream":111,"depth":2,"dek":"Most copper ore is less than 1 percent copper, so mines grind mountains and float the metal out on bubbles.","answer":"Copper ore averages under 0.6 percent copper, so it is crushed to powder and floated in frothy tanks to make a concentrate. A smelter melts the concentrate into matte, converts it to 98 percent blister copper, and fire-refines it. The final purification is electrolytic, producing cathodes of 99.99 percent copper.","aka":["refined copper","copper cathode","electrolytic copper"],"inputs":["copper-ore","water","oxygen","air","sulfuric-acid"],"uses":["hearing-aid","thermometer","microchip","memory-chip","printed-circuit-board","lithium-ion-cell","ev-battery","camera-sensor","solar-panel","refrigerator","microwave-oven","copper-wire","brass","bronze","solder","faucet","padlock","coin","gold-ring","rocket","air-conditioner","flute","toy-car","medal","bell","stained-glass","light-switch","power-outlet","brake-pad","spark-plug","game-console","wifi-router","graphics-card","jeans"],"grounds":["copper-ore","water","air","sulfur"],"upstreamSlugs":["copper-ore","water","oxygen","air","sulfuric-acid","sulfur"],"downstreamSlugs":["hearing-aid","thermometer","microchip","memory-chip","printed-circuit-board","lithium-ion-cell","ev-battery","camera-sensor","solar-panel","refrigerator","microwave-oven","copper-wire","brass","bronze","solder","faucet","padlock","coin","gold-ring","rocket","air-conditioner","flute","toy-car","medal","bell","stained-glass","light-switch","power-outlet","brake-pad","spark-plug","game-console","wifi-router","graphics-card","jeans","pacemaker","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","smartwatch","wireless-earbuds","phone-charger","usb-cable","digital-camera","e-reader","inkjet-printer","remote-control","electric-toothbrush","led-bulb","hard-drive","wind-turbine","washing-machine","car","airplane","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","smoke-detector","headphones","electric-motor","transformer","vacuum-cleaner","electric-kettle","container-ship","electric-guitar","piano","toaster","power-cable","loudspeaker","microphone","aa-battery","wristwatch","tire","trumpet","ballpoint-pen","pencil-eraser","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","leather-belt","handbag","flag","zipper","drum-kit","bronze-statue","eyeglass-frame","skyscraper","dishwasher","subway-train","bicycle","down-jacket","raincoat","backpack","suitcase"],"steps":[{"name":"Crush the ore to powder","process":"crush","text":"The average grade of copper ore this century is below 0.6 percent. Rock is ground to particles under 100 micrometers, fine enough that each grain is one mineral.","inputs":["copper-ore"]},{"name":"Float the copper sulfide","process":"separate","text":"The powder is mixed into a slurry with chemicals that make the copper sulfide grains repel water. Air is pumped through, and the copper grains cling to bubbles and rise as a froth that is skimmed off. The waste rock sinks as tailings.","inputs":["water"]},{"name":"Smelt the concentrate to matte","process":"melt","text":"The concentrate is melted in a flash furnace or similar smelter with oxygen-enriched air. Iron and sulfur burn off, and a heavy copper-rich matte sinks under a floating layer of slag.","inputs":["oxygen"]},{"name":"Convert it to blister copper","process":"refine","text":"Air is blown through the matte to burn out the remaining iron and sulfur. What is left is about 98 percent copper. It is called blister because sulfur dioxide escaping on cooling leaves a broken surface. The gas is captured and made into sulfuric acid.","inputs":["air"]},{"name":"Fire-refine in an anode furnace","process":"refine","text":"In a furnace, remaining sulfur and iron are oxidized away, and then oxygen is removed by blowing natural gas or another reducing agent through the melt, in a step called poling. The metal is cast into flat anodes.","inputs":[]},{"name":"Plate pure copper by electrolysis","process":"electrolyze","text":"The anodes hang in baths of copper sulfate and sulfuric acid, facing thin sheets of pure copper or stainless steel. Current drives copper off the anode and onto the cathode, and valuable silver, gold, selenium and tellurium fall to the bottom as anode slime.","inputs":["sulfuric-acid"],"spec":"99.99% pure cathode"}],"facts":["More than 95 percent of all the copper ever mined and smelted has been extracted since 1900.","A copper smelter makes sulfuric acid from the sulfur it burns out of the ore, and sulfuric acid is also what leaches copper out of oxide ores.","Oxide ores can skip the smelter, since they are leached in heaps with sulfuric acid and the copper is plated out from the solution."],"where":[{"place":"Chile","share":"at least one-third of world production"},{"place":"United States","share":"second-largest producer"},{"place":"Indonesia","share":"third-largest producer"},{"place":"Peru","share":"fourth-largest producer"}],"whereNote":"2005, copper mine production, per the British Geological Survey.","sources":[{"title":"Copper extraction","url":"https://en.wikipedia.org/wiki/Copper_extraction"},{"title":"Copper","url":"https://en.wikipedia.org/wiki/Copper"},{"title":"Electrorefining","url":"https://en.wikipedia.org/wiki/Electrorefining"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"copper-ore","name":"Copper ore","kind":"raw","category":"ground","title":"How copper ore is mined","url":"https://assemblyline.org/make/copper-ore","stations":4,"upstream":0,"downstream":118,"depth":0,"dek":"Modern copper ore is under 1% copper, so most of every truckload is thrown away.","answer":"Copper comes mainly from huge open pits in rock that holds only a sliver of metal. The rock is crushed to a fine powder, mixed with water and chemicals, and bubbled with air so the copper sulfide particles stick to the bubbles and float off as a froth. The froth is dried into a concentrate for smelting.","aka":["chalcopyrite","porphyry copper"],"inputs":[],"uses":["copper","silver","iridium"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["copper","silver","iridium","hearing-aid","thermometer","microchip","memory-chip","printed-circuit-board","lithium-ion-cell","ev-battery","camera-sensor","solar-panel","refrigerator","microwave-oven","copper-wire","brass","bronze","solder","faucet","padlock","coin","gold-ring","rocket","air-conditioner","flute","toy-car","medal","bell","stained-glass","light-switch","power-outlet","brake-pad","spark-plug","game-console","wifi-router","graphics-card","jeans","solar-cell","mirror","trumpet","thermos","saxophone","smoke-detector","vinyl-record","pacemaker","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","smartwatch","wireless-earbuds","phone-charger","usb-cable","digital-camera","e-reader","inkjet-printer","remote-control","electric-toothbrush","led-bulb","hard-drive","wind-turbine","washing-machine","car","airplane","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","headphones","electric-motor","transformer","vacuum-cleaner","electric-kettle","container-ship","electric-guitar","piano","toaster","power-cable","loudspeaker","microphone","aa-battery","wristwatch","tire","ballpoint-pen","pencil-eraser","fountain-pen","garden-hose","harmonica","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","leather-belt","handbag","flag","zipper","drum-kit","bronze-statue","eyeglass-frame","skyscraper","dishwasher","subway-train","bicycle","down-jacket","raincoat","backpack","suitcase"],"steps":[{"name":"Open the porphyry pit","process":"mine","text":"Most copper is dug from big open pits in so-called porphyry deposits, which hold from 0.4 to 1.0% copper. Ore averaging less than 0.6% is normal in this century, so the pit moves enormous tonnages of rock for a small amount of metal.","inputs":[]},{"name":"Mill to powder","process":"crush","text":"Crushers and rotating mills reduce the rock until it is made of separate mineral particles, each smaller than 100 micrometers. Only at that size can the copper minerals be pried free of the surrounding silicate rock.","inputs":[],"spec":"particles under 100 micrometers"},{"name":"Float the sulfides","process":"separate","text":"In tanks of water, reagents coat the copper sulfide grains so they repel water. Air is pumped through, the grains cling to the bubbles, and the copper-rich froth is skimmed from the top. Lime is used to raise the pH of the bath so the reagents work better.","inputs":[]},{"name":"Leach the oxide ores","process":"wash","text":"Oxidized ores do not float well. Instead they are piled in heaps and soaked in dilute sulfuric acid, which dissolves the copper into a solution that is collected at the bottom of the pile.","inputs":[]}],"facts":["Global copper production was estimated at 22.8 to 22.9 million metric tons in 2024, from ore that averages under 0.6% copper.","The rock left behind after flotation can be reprocessed for other metals, including lead from galena and zinc from sphalerite."],"where":[{"place":"Chile","share":"at least one-third of the world total"},{"place":"United States","share":"second"},{"place":"Indonesia","share":"third"},{"place":"Peru","share":"fourth"}],"whereNote":"Ranking by mined copper in 2005, from the British Geological Survey as quoted on Wikipedia; the source gives no newer ranking.","sources":[{"title":"Copper","url":"https://en.wikipedia.org/wiki/Copper"},{"title":"Copper extraction techniques","url":"https://en.wikipedia.org/wiki/Copper_extraction_techniques"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"copper-wire","name":"Copper wire","kind":"material","category":"metals","title":"How copper wire is made","url":"https://assemblyline.org/make/copper-wire","stations":6,"upstream":7,"downstream":43,"depth":3,"dek":"Copper rod is pulled through die after die, getting longer and thinner each time, never losing volume.","answer":"Copper wire is drawn from cast copper rod. The rod is pulled through a succession of dies, each one narrower than the last, which lengthens it. The metal is annealed between pulls to soften it, because drawing hardens it, and the finished wire is wound on spools. Telephone wire is drawn 20 to 30 times from rod stock.","aka":["electrical wire","magnet wire","copper conductor"],"inputs":["copper"],"uses":["computer-mouse","headphones","solar-panel","wind-turbine","electric-motor","transformer","washing-machine","vacuum-cleaner","electric-kettle","drone","satellite","car","electric-car","airplane","rocket","container-ship","locomotive","motorcycle","elevator","electric-guitar","piano","blender","toaster","ceiling-fan","pinball-machine","power-cable","wireless-earbuds","phone-charger","usb-cable","loudspeaker","microphone","digital-camera","game-console","electric-toothbrush"],"grounds":["copper-ore","water","air","sulfur"],"upstreamSlugs":["copper","copper-ore","water","oxygen","air","sulfuric-acid","sulfur"],"downstreamSlugs":["computer-mouse","headphones","solar-panel","wind-turbine","electric-motor","transformer","washing-machine","vacuum-cleaner","electric-kettle","drone","satellite","car","electric-car","airplane","rocket","container-ship","locomotive","motorcycle","elevator","electric-guitar","piano","blender","toaster","ceiling-fan","pinball-machine","power-cable","wireless-earbuds","phone-charger","usb-cable","loudspeaker","microphone","digital-camera","game-console","electric-toothbrush","refrigerator","microwave-oven","dishwasher","air-conditioner","treadmill","subway-train","inkjet-printer","graphics-card","skyscraper"],"steps":[{"name":"Cast copper rod","process":"cast","text":"Refined copper cathodes are melted and cast continuously into a thick rod, which is then reduced by rolling into a coil that wire drawers buy as their raw material.","inputs":["copper"]},{"name":"Clean the rod","process":"wash","text":"The rod is cleaned so the surface is bright and smooth. Dirt or oxide here would scratch the dies and the wire.","inputs":[]},{"name":"Pull it through a row of dies","process":"draw","text":"A drum pulls the wire through a hole in a die, and the wire gets thinner and longer. The dies are made of tungsten carbide or diamond. A continuous machine has a series of dies, with 3 to 12 per machine, and each drum turns faster than the one before.","inputs":[]},{"name":"Anneal to restore softness","process":"heat-treat","text":"Cold working leaves the metal hard. Heating it between draws counters that, and a last anneal on the finished wire maximizes both its ductility and its electrical conductivity.","inputs":[]},{"name":"Draw it fine","process":"draw","text":"Fine wire goes through smaller and smaller dies, with a lubricant bath to keep friction down. Very fine wires are often drawn several together in a bundle.","inputs":[]},{"name":"Spool or strand it","process":"package","text":"Finished wire is wound onto spools. Several thin wires can be twisted together into stranded cable, which bends more easily than one thick wire.","inputs":[]}],"facts":["Electrical wire takes about 60 percent of all the copper used.","Copper is the preferred electrical conductor in almost every kind of wiring, except overhead power transmission lines, where aluminum is often preferred.","In some wire, a thin copper film is left on after drawing to prevent rust or help with soldering."],"where":[],"whereNote":null,"sources":[{"title":"Wire drawing","url":"https://en.wikipedia.org/wiki/Wire_drawing"},{"title":"Copper","url":"https://en.wikipedia.org/wiki/Copper"},{"title":"Wire","url":"https://en.wikipedia.org/wiki/Wire"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"copra","name":"Copra","kind":"material","category":"food","title":"How copra is made","url":"https://assemblyline.org/make/copra","stations":5,"upstream":1,"downstream":1,"depth":1,"dek":"A thousand coconuts weighing 1,440 kilograms yield about 170 kilograms of copra and 70 liters of oil.","answer":"Copra is dried coconut meat, and it is the form most coconut oil is pressed from. Farmers usually make it where the palms grow, cracking the nuts, draining the water and drying the halves in sun, in smoke or in a kiln. Good copra holds just 4 to 5 percent moisture, which keeps away the molds that ruin it.","aka":["dried coconut meat","coconut kernel"],"inputs":["coconuts"],"uses":["coconut-oil"],"grounds":["coconuts"],"upstreamSlugs":["coconuts"],"downstreamSlugs":["coconut-oil"],"steps":[{"name":"Crack open the nuts","process":"cut","text":"Coconuts are split in two with a chopping knife where they grew, exposing meat that is about 50 percent water and 30 to 40 percent oil. The liquid inside is drained away.","inputs":["coconuts"]},{"name":"Lay halves to the sun","process":"dry","text":"Halves sit on racks with the meat facing the sky. After two days the meat comes away easily from the shell, and drying finishes within seven days in total. This is the oldest method and it gives good white flesh.","inputs":[]},{"name":"Or finish in a kiln","process":"dry","text":"Where humidity is high, a roofed fire pit with a grid above it dries the meat faster. Eight hours of sun can cut a day from kiln time. Starting in the kiln can harden the surface so that it will not dry fully afterward.","inputs":[]},{"name":"Check for damp and mold","process":"inspect","text":"Damp meat grows molds that make aflatoxins, which are potent natural carcinogens. These carry through to copra cake, and then through animal feed into milk or meat. Well-dried material holds 4 to 5 percent moisture and 63 to 70 percent oil.","inputs":[]},{"name":"Sack it for the mill","process":"package","text":"Dried pieces are packed and shipped to oil mills, often overseas. There they are crushed for oil, and the remaining cake, 18 to 25 percent protein, goes to feed cattle and other ruminants.","inputs":[]}],"facts":["Crushing copra gives about 70% coconut oil and 30% copra cake.","Whole small coconuts can be dried for eight months to a year in India, and the meat is then sold as a single ball.","Copra became a valuable commodity for South Seas merchants in the 1860s."],"where":[],"whereNote":null,"sources":[{"title":"Copra","url":"https://en.wikipedia.org/wiki/Copra"},{"title":"Copra (Britannica)","url":"https://www.britannica.com/topic/copra"},{"title":"Coconut oil","url":"https://en.wikipedia.org/wiki/Coconut_oil"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cork-bark","name":"Cork oak bark","kind":"raw","category":"farm","title":"How cork bark is harvested","url":"https://assemblyline.org/make/cork-bark","stations":3,"upstream":0,"downstream":4,"depth":0,"dek":"Cork is peeled off living oaks with hand axes, and the same tree grows a new layer.","answer":"Cork is the thick outer bark of the cork oak, peeled by hand with a small axe in summer while the tree keeps standing. A tree can be stripped first at about 25 years old and again every nine years or so. The first harvests are rough, and bark good enough for wine stoppers comes later.","aka":["cork oak bark","cork","natural cork"],"inputs":[],"uses":["cork-stopper","fishing-rod","flute"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["cork-stopper","fishing-rod","flute","champagne"],"steps":[{"name":"Wait for the thick bark","process":"grow","text":"The cork oak grows slowly in warm Mediterranean forests. It is ready for its first stripping at roughly 25 years old, when the trunk reaches about 60 centimeters around.","inputs":[],"spec":"first harvest around 25 years"},{"name":"Peel the bark with axes","process":"harvest","text":"A crew of about five people cuts the bark into planks with small axes. Stripping only happens from May to August, when the bark separates cleanly without hurting the tree.","inputs":[],"spec":"May to August only"},{"name":"Stack the planks to dry","process":"dry","text":"The planks are carried out by hand because the forests are hard to reach by vehicle. They are piled in the forest or a factory yard and left to dry before shipping.","inputs":[]}],"facts":["Cork oaks can live for about 300 years and keep growing new bark after each stripping.","Cork is made of dead cells filled with an air-like gas, which is why it springs back after being squeezed.","Portugal manages about 34 percent of the Mediterranean cork oak forest and produces about half of the world's cork."],"where":[],"whereNote":null,"sources":[{"title":"Cork (material)","url":"https://en.wikipedia.org/wiki/Cork_(material)"},{"title":"Quercus suber","url":"https://en.wikipedia.org/wiki/Quercus_suber"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"corn","name":"Corn","kind":"raw","category":"farm","title":"How corn is grown and harvested","url":"https://assemblyline.org/make/corn","stations":3,"upstream":0,"downstream":364,"depth":0,"dek":"A big cob can carry up to 1200 kernels packed in rows, and every one of them started as a strand of silk.","answer":"Corn is planted in spring because it cannot tolerate cold, and it grows into a stalk several meters tall. Wind carries pollen from the tassel to the silks on each ear, and every silk produces one kernel. For grain, a combine picks the ears and shells the kernels once they have dried in the field.","aka":["maize","corn farming","corn harvest","field corn"],"inputs":[],"uses":["penicillin","ethanol","corn-syrup","corn-starch","tortilla","corn-flakes","popcorn","beer","whiskey","vodka","carbon-dioxide","bourbon"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["penicillin","ethanol","corn-syrup","corn-starch","tortilla","corn-flakes","popcorn","beer","whiskey","vodka","carbon-dioxide","bourbon","deodorant","perfume","vaccine","gasoline","ink","vanilla-extract","vinegar","gin","lacquer","super-glue","port-wine","insect-repellent","air-freshener","hairspray","mouthwash","gummy-bears","marshmallow","jelly-beans","candy-cane","chewing-gum","sprinkles","cola","granola-bar","caramel-color","caramel","lollipop","soda","tonic-water","light-beer","aspirin","vitamin-c","chicken-nuggets","imitation-crab","canned-soup","wallpaper","cotton-fabric","soda-ash","fertilizer","baking-soda","decaf-coffee","sparkling-water","refrigerant","popping-candy","root-beer","energy-drink","non-alcoholic-beer","caffeine","melamine-resin","ethylene-glycol","shampoo","dish-soap","foundation-makeup","car","car-engine","motorcycle","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","ice-cream","white-chocolate","mayonnaise","ketchup","mustard","hot-sauce","salsa","pickles","guitar","electric-guitar","trumpet","chopsticks","door","chess-set","saxophone","ukulele","felt-hat","baseball-bat","donut","rum","flour","adhesive-bandage","duct-tape","sofa","pillow","handbag","rubber-boots","sneaker","baseball-cap","detergent","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","instant-noodles","stained-glass","vanadium","pretzel","frozen-pizza","bagel","crackers","cake-mix","fire-extinguisher","refrigerator","air-conditioner","asthma-inhaler","pet-plastic","spandex","locomotive","vacuum-cleaner","electric-kettle","cotton-candy","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","hard-cider","electric-car","soap","toothpaste","nitrile-glove","washing-machine","paperclip","crayon","fireworks","candle","fish-sticks","zip-bag","blender","dishwasher","cotton-swab","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","bread","croissant","sandwich-cookie","baguette","sourdough","modeling-clay","licorice","printed-circuit-board","wind-turbine","surfboard","fishing-rod","kite","roof-shingle","canoe","sailboat","lithium-ion-cell","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather","thermometer","lcd-screen","oled-screen","camera-sensor","solar-panel","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","neon-sign","smartwatch","e-reader","mirror","skyscraper","double-glazed-window","nail-polish","insulin","wine","champagne","tequila","sake","kombucha","scotch","cognac","mezcal","mead","prosecco","smartphone","polyester","plastic-bottle","3d-printer-filament","drum-kit","bottled-water","leggings","swimsuit","pencil","scissors","airplane","container-ship","shipping-container","bicycle","wooden-chair","water-bottle","ceiling-fan","tennis-racket","golf-club","billiard-ball","dartboard","dice","action-figure","fashion-doll","toy-car","coil-spring","hammer","gas-cylinder","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","hearing-aid","pacemaker","led-bulb","ev-battery","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","airbag","rocket","elevator","treadmill","pinball-machine","phone-charger","digital-camera","graphics-card","electric-toothbrush","kitchen-knife","fork","fountain-pen","thermos","pressure-cooker","jet-engine","football","winter-gloves","wallet","hiking-boots","high-heels","leather-shoe","sauerkraut","jam","hazelnut-spread","tire","office-chair","garden-hose","volleyball","kitchen-sponge","wet-wipes","seat-belt","hoodie","raincoat","backpack","suitcase","shoelace","curtain","microphone","mattress","zipper","button","thread","teddy-bear","sunscreen","bleach","hair-dye","padlock","down-jacket","jeans","dress-shirt","suit","bike-helmet","yo-yo","tampon","silk-tie","blanket","socks","sweater","towel"],"steps":[{"name":"Plant after the frost","process":"grow","text":"Corn is cold-intolerant, so in temperate zones it goes in during spring. Its roots are shallow, so the plant leans heavily on soil moisture, and it is most sensitive to drought just as the silks appear.","inputs":[]},{"name":"Pollinate by wind","process":"grow","text":"The tassel at the top releases pollen, and wind carries it down to the ears. Each plant carries separate male and female flowers. Kernels grow in 8 to 32 rows around a cob, and a large cob can carry up to 1200 of them.","inputs":[],"spec":"up to 1200 kernels per cob"},{"name":"Pick and shell the ears","process":"harvest","text":"Grain corn can stand in the field for months after it matures. A picker takes the whole ear, and a separate sheller strips the kernels from the cob. Sweet corn is picked much earlier, at the milk stage, 60 to 100 days after planting.","inputs":[]}],"facts":["More corn is grown each year, by weight, than any other grain.","Before 1940, most North American corn was harvested by hand, often at social gatherings called husking bees.","Because corn is a C4 plant, it uses water more efficiently than alfalfa or soybeans."],"where":[{"place":"United States","share":"31.0% of world output"},{"place":"China","share":"22.4%"}],"whereNote":"2020, share of the 1.16 billion tonnes of maize produced worldwide.","sources":[{"title":"Maize","url":"https://en.wikipedia.org/wiki/Maize"},{"title":"Combine harvester","url":"https://en.wikipedia.org/wiki/Combine_harvester"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"corn-flakes","name":"Corn flakes","kind":"product","category":"food","title":"How corn flakes are made","url":"https://assemblyline.org/make/corn-flakes","stations":8,"upstream":60,"downstream":0,"depth":10,"dek":"Corn flakes started as a happy accident of rolling out stale cooked dough in a Michigan sanatorium in 1894.","answer":"Corn grits cook with water, sugar, malt syrup and salt until soft and pliable at about 24% moisture. They are dried and rested for hours until the moisture falls to about 14%, softened with humid heat, squeezed flat between flaking rolls, and toasted at 300 to 400 °F to a blistered, crisp 2% moisture.","aka":["cornflakes","breakfast cereal","toasted corn flakes"],"inputs":["corn","water","sugar","malted-barley","table-salt","cardboard-box"],"uses":[],"grounds":["corn","water","sugarcane","sugar-beet","barley","rock-salt","seawater","limestone","timber","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","coal","natural-gas"],"upstreamSlugs":["corn","water","sugar","malted-barley","table-salt","cardboard-box","sugarcane","sugar-beet","lime","barley","rock-salt","seawater","cardboard","ink","adhesive","limestone","wood-pulp","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","timber","caustic-soda","oxygen","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","yeast","ethylene","propylene","ammonia","methanol","acetone","nitric-acid","hydrogen","benzene","coal","molasses","naphtha","natural-gas","toluene"],"downstreamSlugs":[],"steps":[{"name":"Mill the grits","process":"crush","text":"Corn is milled into coarse grits, each of which will become roughly one flake. Grits are the normal starting point for the traditional cook-and-flake route.","inputs":["corn"]},{"name":"Cook with malt and sugar","process":"cook","text":"The grits cook with enough water, sugar, malt syrup and salt to end up soft and pliable. One General Foods patent example reaches 24% moisture at this stage.","inputs":["water","sugar","malted-barley","table-salt"],"spec":"about 24% moisture"},{"name":"Dry the cooked grits","process":"dry","text":"Vertical dryers pull water out of the sticky cooked grits. Faster plants can use a multi-pass traveling screen dryer with controlled humidity and airflow instead, which takes about 30 minutes.","inputs":[]},{"name":"Temper in bins","process":"dry","text":"The dried grits rest in tempering bins, about 7 hours in the patent's example, so that moisture evens out through each particle. They come out at about 14%.","inputs":[],"spec":"about 14% moisture"},{"name":"Soften with humid heat","process":"heat-treat","text":"A short pass through humid air warms the grits to around 152 °F. Moisture stays about the same, but the grit turns plastic enough to flatten instead of crumble.","inputs":[]},{"name":"Squeeze between rolls","process":"roll","text":"Warm grits drop from a feed hopper into the nip of the flaking rolls and come out as thin, soft flakes.","inputs":[]},{"name":"Toast until blistered","process":"bake","text":"A toasting oven at 300 to 400 °F browns the flakes and raises blisters on their surface. Moisture drops to about 2%, which gives the crunch.","inputs":[],"spec":"300-400 °F"},{"name":"Coat and pack","process":"coat","text":"Toasted flakes can be eaten as they are or coated with a sugar layer carrying vitamins and minerals, then bagged and boxed.","inputs":["sugar","cardboard-box"]}],"facts":["John Harvey Kellogg received a patent for flaked cereals on April 14, 1896.","The first flakes were made from wheat, and corn came later.","When Will Kellogg added sugar to the flakes for the mass market, it caused a rift with his brother."],"where":[],"whereNote":null,"sources":[{"title":"US4013802A: Corn flake process and product (General Foods)","url":"https://patents.google.com/patent/US4013802"},{"title":"Corn flakes","url":"https://en.wikipedia.org/wiki/Corn_flakes"},{"title":"Breakfast cereal","url":"https://en.wikipedia.org/wiki/Breakfast_cereal"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"corn-starch","name":"Corn starch","kind":"material","category":"food","title":"How corn starch is made","url":"https://assemblyline.org/make/corn-starch","stations":6,"upstream":2,"downstream":49,"depth":1,"dek":"Corn is soaked until it ferments slightly, then the starch is washed out of it with water.","answer":"Starch factories steep whole corn kernels in warm water for 30 to 48 hours until the grain softens and ferments a little. Mills grind the soaked kernels, separate the germ and fiber, and wash starch out of the endosperm. Hydrocyclones and centrifuges then isolate the starch, which is dried to a white powder.","aka":["cornflour","maize starch","cornstarch"],"inputs":["corn","water"],"uses":["aspirin","vitamin-c","corn-syrup","chicken-nuggets","gummy-bears","marshmallow","jelly-beans","candy-cane","sprinkles","imitation-crab","canned-soup","wallpaper","cotton-fabric"],"grounds":["corn","water"],"upstreamSlugs":["corn","water"],"downstreamSlugs":["aspirin","vitamin-c","corn-syrup","chicken-nuggets","gummy-bears","marshmallow","jelly-beans","candy-cane","sprinkles","imitation-crab","canned-soup","wallpaper","cotton-fabric","flour","chewing-gum","cola","granola-bar","caramel-color","caramel","lollipop","soda","tonic-water","light-beer","donut","adhesive-bandage","duct-tape","sofa","pillow","handbag","rubber-boots","book","sneaker","baseball-cap","bread","instant-noodles","tortilla","croissant","pretzel","sandwich-cookie","frozen-pizza","bagel","baguette","sourdough","crackers","fish-sticks","modeling-clay","licorice","cake-mix","rum"],"steps":[{"name":"Soak the kernels","process":"wash","text":"Whole corn sits in steeping tanks of warm water for 30 to 48 hours. The soak softens the kernels and ferments them slightly, which loosens the starch from the protein that holds it.","inputs":["corn","water"],"spec":"30 to 48 hours"},{"name":"Split off the germ","process":"separate","text":"Coarse mills tear the swollen kernels open, and the germ floats off. The germ is the oil-rich part, so it goes on to make corn oil.","inputs":[]},{"name":"Grind the rest finer","process":"crush","text":"The germ and the endosperm are ground separately while still wet. Fine grinding frees the starch granules from the fiber that traps them.","inputs":[]},{"name":"Wash the starch out","process":"separate","text":"Screens catch the fiber while the starch and protein wash through as a milky stream. Hydrocyclones and centrifuges spin the stream so that heavy starch separates from corn gluten and steep liquor.","inputs":[]},{"name":"Dry to a powder","process":"dry","text":"The wet starch cake is dried in hot air until it is a fine white powder. Everything that was separated out, including the fiber, gluten and steep liquor, goes on to make animal feed or other products.","inputs":[]},{"name":"Modify it if needed","process":"react","text":"Starch headed for specific uses may be chemically or physically modified. Examples include starch that thickens without clumping or that resists breaking down under heat.","inputs":[]}],"facts":["Corn starch was used mostly for stiffening laundry until a method for pure culinary starch was patented in 1854.","Fine starch dust can explode, and the 2015 Formosa Fun Coast fire in Taiwan is believed to have started with overheated corn starch based powder.","Mixed with a little water, corn starch becomes a non-Newtonian fluid that is runny when poured and hard when punched."],"where":[],"whereNote":null,"sources":[{"title":"Corn starch","url":"https://en.wikipedia.org/wiki/Corn_starch"},{"title":"Corn syrup","url":"https://en.wikipedia.org/wiki/Corn_syrup"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"corn-syrup","name":"Corn syrup","kind":"material","category":"food","title":"How corn syrup is made","url":"https://assemblyline.org/make/corn-syrup","stations":6,"upstream":3,"downstream":16,"depth":2,"dek":"Enzymes chop corn starch into glucose, and a second enzyme can bend part of it into sweeter fructose.","answer":"Corn is wet-milled to pull out the starch. Then enzymes do the work. One breaks the starch into short chains, another snips those chains into single glucose units, and the resulting liquid is filtered and evaporated to a thick syrup. A third enzyme can turn part of the glucose into sweeter fructose.","aka":["glucose syrup","high-fructose corn syrup","HFCS"],"inputs":["corn","corn-starch","water"],"uses":["gummy-bears","marshmallow","jelly-beans","candy-cane","chewing-gum","sprinkles","cola","granola-bar","caramel-color","caramel","lollipop","soda","tonic-water","light-beer"],"grounds":["corn","water"],"upstreamSlugs":["corn","corn-starch","water"],"downstreamSlugs":["gummy-bears","marshmallow","jelly-beans","candy-cane","chewing-gum","sprinkles","cola","granola-bar","caramel-color","caramel","lollipop","soda","tonic-water","light-beer","donut","rum"],"steps":[{"name":"Wet-mill the corn","process":"separate","text":"Number 2 yellow dent corn is soaked and ground, and its starch is washed free of germ, fiber and protein. The result is a milky starch slurry.","inputs":["corn"]},{"name":"Chop with bacterial enzyme","process":"react","text":"Starch is mixed with water and the enzyme alpha-amylase, which comes from Bacillus bacteria grown in a fermenter. It cuts the long starch molecules into shorter chains called oligosaccharides.","inputs":["corn-starch","water"]},{"name":"Snip into glucose","process":"react","text":"A second enzyme, glucoamylase from the fungus Aspergillus, removes glucose units from the ends of the short chains. How far this reaction runs sets the syrup's dextrose equivalent. Less reaction makes a thicker, less sweet syrup, and more makes a thinner, sweeter one.","inputs":[]},{"name":"Filter and decolorize","process":"refine","text":"The sweet liquid is filtered to remove protein and fat, then passed over carbon and ion-exchange resin to take out color and salts.","inputs":[]},{"name":"Evaporate to syrup","process":"cook","text":"Vacuum evaporators boil off water until the liquid is thick and about one third glucose by weight in the common grades. Light corn syrup is seasoned with vanilla and salt, and dark corn syrup has refiner's syrup, caramel color and flavor added.","inputs":[]},{"name":"Convert some to fructose","process":"react","text":"For high-fructose corn syrup, the glucose syrup is run through columns packed with the enzyme D-xylose isomerase. Part of the glucose rearranges into fructose, and the result is sweeter and dissolves better.","inputs":[]}],"facts":["It takes about 60 bushels of corn to make one short ton of glucose syrup.","The first corn syrup was made in 1811 by boiling starch with hydrochloric acid, and enzymes took over later."],"where":[],"whereNote":null,"sources":[{"title":"Corn syrup","url":"https://en.wikipedia.org/wiki/Corn_syrup"},{"title":"Corn starch","url":"https://en.wikipedia.org/wiki/Corn_starch"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cotton-candy","name":"Cotton candy","kind":"product","category":"food","title":"How cotton candy is made","url":"https://assemblyline.org/make/cotton-candy","stations":9,"upstream":57,"downstream":0,"depth":11,"dek":"Cotton candy is sugar melted and flung through a spinning screen, where it freezes into hair-thin strands in midair.","answer":"Floss sugar, treated to form fibers and blended with dye and flavor, falls from a hopper into a spinning heated cylinder with holes in its side. Molten threads fly out and harden in a surrounding pan. A carnival operator twirls them onto a cone, while a factory machine rolls them into a block, slices it and seals the pieces in bags.","aka":["candy floss","fairy floss","spun sugar"],"inputs":["sugar","plastic-bag","cardboard-box"],"uses":[],"grounds":["sugarcane","sugar-beet","water","limestone","natural-gas","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","timber","rock-salt","coal"],"upstreamSlugs":["sugar","plastic-bag","cardboard-box","sugarcane","sugar-beet","water","lime","polyethylene","ink","cardboard","adhesive","limestone","ethylene","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","wood-pulp","acrylic","epoxy","polyurethane","paraffin-wax","naphtha","natural-gas","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","yeast","timber","caustic-soda","hydrogen-peroxide","propylene","ammonia","methanol","acetone","nitric-acid","hydrogen","benzene","rock-salt","coal","molasses","toluene"],"downstreamSlugs":[],"steps":[{"name":"Tint the floss sugar","process":"mix","text":"The sugar is specially treated to form fibers. Federally regulated dyes and natural or artificial flavors go in, because plain sugar spins out white.","inputs":["sugar"]},{"name":"Load the hopper","process":"fill","text":"Sugar goes into a large stainless steel hopper. Its tapered bottom funnels the granules down into the extruder, a metal cylinder with holes along its sides.","inputs":[]},{"name":"Melt in the cylinder","process":"melt","text":"A heating element inside the extruder turns the granules into a thick, sticky liquid. Crystal size matters, since very fine sugar can fly out unmelted.","inputs":[]},{"name":"Fling through holes","process":"spin","text":"The cylinder spins and throws liquid sugar out through its holes in every direction. It leaves as threads many times thinner than a hair.","inputs":[],"spec":"3,450 revolutions per minute"},{"name":"Catch the cooling strands","process":"chill","text":"Threads turn solid as they leave and land in a wide circular pan. Air trapped between them gives the fluff. Plants keep moisture low here, or the strands clump together.","inputs":[]},{"name":"Gather onto cone or belt","process":"assemble","text":"At a carnival, the operator circles a cardboard cone around the pan and the sticky strands cling to it. Automated machines pull them onto a conveyor instead.","inputs":[]},{"name":"Roll into a block","process":"press","text":"Non-stick rollers above and beside the belt shape the bundle into a continuous block of fixed height and width. They press gently, because too much force changes the texture.","inputs":[]},{"name":"Slice into segments","process":"cut","text":"A vertical knife slides down through the moving block at set intervals, then retracts. Another roller presses each segment back into shape.","inputs":[]},{"name":"Bag against moisture","process":"package","text":"Each piece is sealed in a plastic bag, since water vapor turns the candy rubbery and sticky. Bags get a date and batch code, then go into boxes. Sealed well, it lasts about six months.","inputs":["plastic-bag","cardboard-box"]}],"facts":["The machine was invented in 1897 by a dentist, William Morrison, and a confectioner, John C. Wharton.","At the 1904 World's Fair the candy, then called Fairy Floss, sold 68,655 boxes.","Mass production waited until 1972, when an automatic machine that could also package the candy was patented."],"where":[],"whereNote":null,"sources":[{"title":"Cotton Candy, How Products Are Made (Gale), Encyclopedia.com","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/cotton-candy"},{"title":"Cotton candy","url":"https://en.wikipedia.org/wiki/Cotton_candy"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cotton-fabric","name":"Cotton fabric","kind":"material","category":"textiles","title":"How cotton fabric is woven","url":"https://assemblyline.org/make/cotton-fabric","stations":6,"upstream":5,"downstream":9,"depth":2,"dek":"Woven cloth is two sets of threads crossing at right angles, and the loom has to repeat that millions of times.","answer":"Cotton fabric is made on a loom that crosses two sets of yarn at right angles. The lengthwise warp yarns are sized with starch so they survive the abuse, strung on the loom, and raised and lowered in a pattern. A weft yarn is shot through the gap each time, and a comb-like reed packs it in tight.","aka":["woven cotton","cotton cloth","calico"],"inputs":["cotton-yarn","corn-starch","water"],"uses":["adhesive-bandage","duct-tape","sofa","pillow","handbag","rubber-boots","book","sneaker","baseball-cap"],"grounds":["water","raw-cotton","corn"],"upstreamSlugs":["cotton-yarn","corn-starch","water","raw-cotton","corn"],"downstreamSlugs":["adhesive-bandage","duct-tape","sofa","pillow","handbag","rubber-boots","book","sneaker","baseball-cap"],"steps":[{"name":"Stiffen the warp with starch","process":"coat","text":"The lengthwise yarns are coated in a starch mixture so that they run smoothly and do not fray while the loom works them.","inputs":["cotton-yarn","corn-starch","water"]},{"name":"Thread the loom","process":"assemble","text":"Each warp yarn is wound onto a big beam and drawn through the eye of a heddle on a frame. Which frame it runs through decides the pattern of the weave.","inputs":[]},{"name":"Open the shed","process":"weave","text":"Frames lift some warp yarns and lower others to make a clear gap, called the shed. The pattern of lifting and lowering picks plain, twill or satin weave, the three basic weaves.","inputs":[]},{"name":"Shoot the weft across","process":"weave","text":"A weft yarn is sent through the shed. Older looms threw a shuttle, and modern shuttleless looms use grippers called rapiers or a blast of air to carry the yarn across.","inputs":["cotton-yarn"]},{"name":"Beat it tight","process":"press","text":"A comb-like reed swings forward to push each new weft yarn against the edge of the finished cloth, called the fell. The cloth advances onto a roll, and the cycle repeats.","inputs":[]},{"name":"Bleach, dye and finish","process":"dye","text":"The loom-state cloth can be bleached, dyed, printed and given finishing treatments or coatings.","inputs":["water"]}],"facts":["The word weft comes from an Old English word meaning that which is woven.","Most woven cloth uses one of three basic weaves: plain, satin or twill.","Cotton is the most widely used natural fiber cloth in clothing today."],"where":[],"whereNote":null,"sources":[{"title":"Weaving","url":"https://en.wikipedia.org/wiki/Weaving"},{"title":"Cotton","url":"https://en.wikipedia.org/wiki/Cotton"},{"title":"Linen","url":"https://en.wikipedia.org/wiki/Linen"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cotton-swab","name":"Cotton swab","kind":"product","category":"body-health","title":"How cotton swabs are made","url":"https://assemblyline.org/make/cotton-swab","stations":6,"upstream":59,"downstream":0,"depth":10,"dek":"Cotton swabs began when a man watched his wife wrap cotton around toothpicks to clean their baby's ears.","answer":"Sticks of rolled paper, plastic or wood are dropped into clips on a moving conveyor. Adhesive goes on the ends, a measured wad of cotton from a coil is attached, and a shaper moving at a different speed from the conveyor rolls the wad into a firm tip. High-speed lines then count the finished swabs into boxes.","aka":["cotton bud","Q-tip","cotton-tipped applicator"],"inputs":["paper","polypropylene","raw-cotton","adhesive","cardboard-box"],"uses":[],"grounds":["raw-cotton","water","kaolin","limestone","timber","crude-oil","rock-salt","air","natural-gas","sulfur","soybeans","rapeseed","clay","titanium-ore","iron-ore","corn","sugarcane","coal","sugar-beet"],"upstreamSlugs":["paper","polypropylene","raw-cotton","adhesive","cardboard-box","wood-pulp","water","kaolin","limestone","propylene","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","cardboard","ink","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","naphtha","crude-oil","ethylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","hydrogen","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","rock-salt","air","natural-gas","sulfur","benzene","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","coke","iron-ore","corn","sugarcane","yeast","toluene","coal","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Make the sticks","process":"extrude","text":"Plastic stems are injection molded or extruded in thin rods from polypropylene or polyethylene. Paper stems are rolled or wrapped into a rigid tube, a more common choice since bans on plastic stems began.","inputs":["paper","polypropylene"]},{"name":"Prepare the cotton","process":"separate","text":"After ginning and carding to align the fibers, the cotton arrives at the factory as loose fiber or a coil of cotton wool.","inputs":["raw-cotton"]},{"name":"Load the conveyor","process":"assemble","text":"Individual sticks are deposited on a continuously moving belt or chain, where clips hold each one.","inputs":[]},{"name":"Glue the ends","process":"coat","text":"An applicator puts adhesive on one or both ends of each stick.","inputs":["adhesive"]},{"name":"Attach and shape the tip","process":"assemble","text":"A portion of cotton coil sticks to the glued end. A shaper bar or belt, moving at a different speed than the conveyor, rolls it against its surface and forms a tight tip under tension.","inputs":[]},{"name":"Check and box","process":"package","text":"Automated lines look over the tips, then count and pack them. Double-tipped swabs get the same treatment at each end in sequence.","inputs":["cardboard-box"]}],"facts":["Leo Gerstenzang developed the first mass-produced swab in 1923 after watching his wife wrap cotton on toothpicks.","The earliest name was Baby Gays, changed to Q-Tips Baby Gays in 1926, where Q stands for quality.","A wooden handle and a paper sleeve let a medical swab be sterilized in an autoclave."],"where":[],"whereNote":null,"sources":[{"title":"US20050145342A1: Process for production of cotton swabs","url":"https://patents.google.com/patent/US20050145342A1/en"},{"title":"Last Object: How cotton swabs are made","url":"https://lastobject.com/blogs/going-zero-waste/how-cotton-swabs-are-made"},{"title":"Cotton swab","url":"https://en.wikipedia.org/wiki/Cotton_swab"},{"title":"Nonwoven fabric","url":"https://en.wikipedia.org/wiki/Nonwoven_fabric"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cotton-yarn","name":"Cotton yarn","kind":"material","category":"textiles","title":"How cotton yarn is made","url":"https://assemblyline.org/make/cotton-yarn","stations":6,"upstream":1,"downstream":22,"depth":1,"dek":"Cotton fibers are only a few centimeters long, and spinning twists them into a strand that can be kilometers long.","answer":"Cotton yarn is made by combing loose, short fibers into parallel order and twisting them. After ginning removes the seeds, the lint is opened, blended, carded into a loose rope, drawn thinner and thinner, and finally twisted on a spinning frame. The finished yarn is wound onto cones for weaving or knitting.","aka":["spun cotton","cotton thread","cotton strand"],"inputs":["raw-cotton"],"uses":["tennis-ball","candle","hoodie","dress-shirt","underwear","shoelace","curtain","cotton-fabric","denim","t-shirt","socks","towel"],"grounds":["raw-cotton"],"upstreamSlugs":["raw-cotton"],"downstreamSlugs":["tennis-ball","candle","hoodie","dress-shirt","underwear","shoelace","curtain","cotton-fabric","denim","t-shirt","socks","towel","adhesive-bandage","duct-tape","sofa","pillow","handbag","rubber-boots","book","sneaker","baseball-cap","jeans"],"steps":[{"name":"Gin out the seeds","process":"separate","text":"Picked cotton is run through a gin that pulls the fiber, called lint, away from the seeds. Before gins, the fibers had to be pulled from the seeds by hand. The leftover seed is pressed for oil.","inputs":["raw-cotton"]},{"name":"Open and blend the bales","process":"mix","text":"Compressed bales are broken open and fibers from several bales are mixed together, so the yarn comes out the same from one bobbin to the next.","inputs":[]},{"name":"Card into a loose rope","process":"separate","text":"Wire-covered rollers comb the tufts of cotton into parallel strands, removing tangles and short bits. The fibers are gathered into a soft rope called a sliver.","inputs":[]},{"name":"Draw it thinner","process":"draw","text":"Pairs of rollers running at different speeds stretch the sliver. Repeated drawing evens out thick and thin spots and turns it into roving, a thin, lightly twisted strand.","inputs":[]},{"name":"Twist on the spinning frame","process":"spin","text":"On a ring spinning frame, the roving is drafted once more and fed through a small traveller that circles a ring. The spindle turns faster than the traveller, which twists the strand while winding it onto a bobbin.","inputs":[]},{"name":"Wind onto cones","process":"package","text":"The yarn is rewound from small bobbins onto large cones, ready for weaving or knitting.","inputs":[]}],"facts":["Short-staple yarn is spun from fibers only 1.9 to 5.1 centimeters long.","The spinning mule, descended from a device invented by Samuel Crompton in 1779, makes a finer, softer and less twisted thread than ring spinning.","Eli Whitney's cotton gin of 1793 helped Britain and the United States raise production, because pulling fibers from seeds by hand had been tediously slow."],"where":[],"whereNote":null,"sources":[{"title":"Spinning (textiles)","url":"https://en.wikipedia.org/wiki/Spinning_(textiles)"},{"title":"Cotton","url":"https://en.wikipedia.org/wiki/Cotton"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cough-syrup","name":"Cough syrup","kind":"product","category":"body-health","title":"How cough syrup is made","url":"https://assemblyline.org/make/cough-syrup","stations":8,"upstream":64,"downstream":0,"depth":10,"dek":"Cough syrup is a sugar solution thick enough to resist crystals, carrying a small measured dose of medicine.","answer":"A syrup plant links a sugar tank, a manufacturing tank and a storage tank by pipeline. Sugar dissolves in purified water first, then the medicine, stabilizers, flavor and color are mixed in, usually on a tank sitting on load cells so the batch is made up by weight. The liquid is filtered, sampled and piped to a bottle filler.","aka":["cough medicine","cough mixture","linctus"],"inputs":["sugar","water","glycerin","plastic-bottle","cardboard-box"],"uses":[],"grounds":["water","sugarcane","sugar-beet","limestone","oil-palm-fruit","soybeans","rapeseed","clay","rock-salt","natural-gas","crude-oil","timber","air","titanium-ore","iron-ore","sulfur","corn","coal"],"upstreamSlugs":["sugar","water","glycerin","plastic-bottle","cardboard-box","sugarcane","sugar-beet","lime","palm-oil","vegetable-oil","caustic-soda","methanol","pet-plastic","cardboard","ink","adhesive","limestone","oil-palm-fruit","soybeans","rapeseed","hexane","clay","rock-salt","natural-gas","p-xylene","ethylene","ethylene-glycol","wood-pulp","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","crude-oil","hydrogen","naphtha","oxygen","carbon-dioxide","timber","hydrogen-peroxide","phenol","formaldehyde","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","yeast","propylene","ammonia","acetone","nitric-acid","benzene","coal","molasses","toluene"],"downstreamSlugs":[],"steps":[{"name":"Weigh out the materials","process":"inspect","text":"Every ingredient is dispensed and weighed against the bill of materials, then moved to the production area.","inputs":[]},{"name":"Dissolve the sugar","process":"cook","text":"Sugar goes into purified water in a dedicated tank, heated until the liquid turns clear and viscous. Heat-sensitive products skip the heat and rely on agitation.","inputs":["sugar","water"]},{"name":"Stop it crystallizing","process":"mix","text":"Stabilizers such as glycerin keep the sucrose from forming crystals, and surfactants help the other ingredients dissolve clear.","inputs":["glycerin"]},{"name":"Blend on load cells","process":"mix","text":"Syrup moves by pipe to the manufacturing tank, where the medicine, flavor and color join it. Common actives are guaifenesin and dextromethorphan. The FDA notes tanks usually sit on load cells, since dipsticks and tank markings have proved inaccurate.","inputs":[]},{"name":"Filter out precipitate","process":"separate","text":"Filtration catches anything that has dropped out of solution, and the clear liquid goes to a storage tank.","inputs":[]},{"name":"Sample the bulk tank","process":"inspect","text":"Most makers assay samples from the bulk before filling. Inspectors also look for microbes, since a contaminant points to a weak process or an inadequate preservative.","inputs":[]},{"name":"Fill the bottles","process":"fill","text":"Storage tank outlets feed a filling machine that doses pre-cleaned bottles. Long delivery lines can harbor contamination, so they have to be cleanable. Measuring devices packed with the bottle must be calibrated.","inputs":["plastic-bottle"]},{"name":"Carton and box","process":"package","text":"Bottles go into cartons and then corrugated boxes, to be kept cool, dry and dark.","inputs":["cardboard-box"]}],"facts":["Cough medicines have been used by 10 percent of American children in any given week, though they are not recommended for children six or younger in Canada or the United States.","In 2015 the FDA warned about codeine-containing cough medication in children."],"where":[],"whereNote":null,"sources":[{"title":"Oral Solutions and Suspensions inspection guide, FDA","url":"https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/inspection-guides/oral-solutions-and-suspensions-894"},{"title":"Liquid Syrup Types and Manufacturing Process, Pharmaguddu","url":"https://pharmaguddu.com/liquid-syrup-types-manufacturing-process/"},{"title":"Cough syrup","url":"https://en.wikipedia.org/wiki/Cough_syrup"},{"title":"Syrup","url":"https://en.wikipedia.org/wiki/Syrup"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"crackers","name":"Crackers","kind":"product","category":"food","title":"How crackers are made","url":"https://assemblyline.org/make/crackers","stations":7,"upstream":37,"downstream":0,"depth":9,"dek":"The holes in a cracker are there on purpose, to stop big air bubbles from puffing the dough into a balloon.","answer":"Crackers start as a stiff flour dough, either yeast-fermented like a saltine or chemically leavened like most snack crackers. The dough is rolled into a thin sheet, pricked with holes and cut into shapes. A hot oven bakes out nearly all the water. Salt or seasoning is sprinkled on before or after baking.","aka":["saltines","soda crackers","water biscuits"],"inputs":["flour","water","yeast","baking-soda","table-salt","vegetable-oil"],"uses":[],"grounds":["water","wheat","trona","limestone","rock-salt","seawater","soybeans","rapeseed","clay","air","sugarcane","sugar-beet","natural-gas","corn","crude-oil"],"upstreamSlugs":["flour","water","yeast","baking-soda","table-salt","vegetable-oil","wheat","vitamin-c","molasses","trona","limestone","ammonia","rock-salt","soda-ash","carbon-dioxide","seawater","soybeans","rapeseed","hexane","clay","corn-starch","hydrogen","air","sugar","plastic-bottle","sugarcane","sugar-beet","natural-gas","lime","corn","crude-oil","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen"],"downstreamSlugs":[],"steps":[{"name":"Mix the cracker dough","process":"mix","text":"Flour, water and a little fat are mixed. Soda crackers use yeast and baking soda, while snack crackers usually rely on chemical leavening alone. Soda crackers have no added sugar and little fat.","inputs":["flour","water","yeast","baking-soda"]},{"name":"Ferment the sponge","process":"ferment","inputs":[],"spec":"16 to 20 hours at 27 °C","text":"A classic soda cracker starts with a sponge of flour, water and yeast that sours for most of a day. Then more flour, fat and baking soda go in and the dough rests again. Crackers with no leavening, like matzo, skip this step."},{"name":"Layer and thin the sheet","process":"roll","inputs":[],"spec":"2 to 4 mm thick","text":"Rollers stretch the dough into a continuous sheet, which is folded into 4 to 6 layers and rolled down again. The layers give a soda cracker its flaky bite."},{"name":"Dock and cut","process":"stamp","text":"A die pokes small holes across the sheet and cuts out square, round or fancy shapes. The holes, called docking holes, stop large air pockets from forming during baking.","inputs":[]},{"name":"Salt the tops","process":"coat","inputs":["table-salt"],"text":"Salt, seeds, herbs or cheese are sprinkled over the cut pieces on the moving band."},{"name":"Bake dry and crisp","process":"bake","inputs":[],"spec":"2 to 4 minutes at up to 300 °C","text":"A very hot oven drives the moisture down to about 1.5 to 2.5 percent in a few minutes. Low moisture is what lets crackers sit on a shelf for months."},{"name":"Spray, cool and stack","process":"coat","inputs":["vegetable-oil"],"text":"Many crackers get a mist of oil straight from the oven. They cool on the line and are stacked and wrapped in sleeves."}],"facts":["Hardtack, the ancestor of the cracker, was recorded as far back as 1190 as a convenience food for soldiers and sailors.","In 1876 a Missouri company began using baking soda as the leavener in a wafer-thin cracker, which became the saltine."],"where":[],"whereNote":null,"sources":[{"title":"Cracker (food)","url":"https://en.wikipedia.org/wiki/Cracker_(food)"},{"title":"Saltine cracker","url":"https://en.wikipedia.org/wiki/Saltine_cracker"},{"title":"Crackers","url":"https://bakerpedia.com/processes/crackers/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"crayon","name":"Crayon","kind":"product","category":"play","title":"How crayons are made","url":"https://assemblyline.org/make/crayon","stations":7,"upstream":57,"downstream":0,"depth":10,"dek":"A crayon is mostly paraffin wax, dyed and poured into a mold like a candle.","answer":"A crayon is paraffin wax mixed with pigment. The wax is heated until it flows, dyed and poured into molds shaped like rods. It cools and sets. The sticks are popped out, trimmed, wrapped in a paper label, and packed in boxes by color. The standard crayon is about 3.5 inches long.","aka":["wax crayon","wax pastel"],"inputs":["paraffin-wax","titanium-dioxide","pigment","paper","cardboard-box"],"uses":[],"grounds":["crude-oil","titanium-ore","iron-ore","sulfur","water","kaolin","limestone","natural-gas","rock-salt","coal","air","timber","soybeans","rapeseed","clay","corn","sugarcane","sugar-beet"],"upstreamSlugs":["paraffin-wax","titanium-dioxide","pigment","paper","cardboard-box","crude-oil","hydrogen","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","carbon-black","sulfur","wood-pulp","water","kaolin","limestone","cardboard","ink","adhesive","natural-gas","rock-salt","coal","air","timber","caustic-soda","lime","hydrogen-peroxide","vegetable-oil","phenolic-resin","ethanol","polyethylene","acrylic","epoxy","polyurethane","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","corn","sugarcane","yeast","ethylene","propylene","ammonia","methanol","acetone","nitric-acid","benzene","molasses","naphtha","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Melt the wax","process":"melt","text":"Paraffin wax is heated in a tank until it is just warm enough to flow. Temperature is controlled closely, because the wax has to be liquid yet cool enough to mix evenly.","inputs":["paraffin-wax"]},{"name":"Stir in the pigment","process":"mix","text":"Color is stirred into the melted wax, along with any fillers. Each color gets its own batch, mixed until it is the same all the way through.","inputs":["titanium-dioxide","pigment"]},{"name":"Pour into the molds","process":"cast","text":"The colored wax is poured into metal molds with hundreds of crayon-shaped cavities.","inputs":[]},{"name":"Chill until set","process":"chill","text":"Cool water circulates around the molds until the wax is hard. The crayons shrink slightly as they solidify.","inputs":[]},{"name":"Pop them out","process":"assemble","text":"The molds open, and the finished sticks are pushed out and sorted. Crooked or cracked ones go back into the melting tank.","inputs":[]},{"name":"Wrap in paper labels","process":"package","text":"A machine rolls each crayon in a paper wrapper printed with its color name and brand.","inputs":["paper"]},{"name":"Box by color","process":"package","text":"Wrapped crayons are counted into boxes. The first Crayola box, in 1903, held eight colors.","inputs":["cardboard-box"]}],"facts":["The name Crayola was coined in 1903 by Alice Stead Binney, wife of Edwin Binney, from the French craie (chalk) and the first part of oleaginous.","Washable crayons were developed by chemist Colin Snedeker, who was awarded a patent in 1990.","Jane Austen's Pride and Prejudice mentions crayons, in 1813."],"where":[],"whereNote":null,"sources":[{"title":"Crayon","url":"https://en.wikipedia.org/wiki/Crayon"},{"title":"Paraffin wax","url":"https://en.wikipedia.org/wiki/Paraffin_wax"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cream","name":"Cream","kind":"material","category":"food","title":"How cream is made","url":"https://assemblyline.org/make/cream","stations":5,"upstream":1,"downstream":7,"depth":1,"dek":"A dairy does not skim anything. It spins milk so hard that the fat leaves through its own pipe.","answer":"Butterfat is lighter than the rest of milk, and left alone it floats to the top. Dairies speed that up with centrifugal separators, which split whole milk into cream and skim in a continuous stream. The cream is then adjusted to a legal fat grade, heat-treated and packed, from half and half up to heavy cream.","aka":["heavy cream","whipping cream","double cream","single cream"],"inputs":["raw-milk"],"uses":["butter","ice-cream","cream-cheese","sour-cream","caramel"],"grounds":["raw-milk"],"upstreamSlugs":["raw-milk"],"downstreamSlugs":["butter","ice-cream","cream-cheese","sour-cream","caramel","croissant","toffee"],"steps":[{"name":"Spin the whole milk","process":"separate","text":"Milk runs into a fast-turning centrifugal separator. The less dense butterfat collects apart from the skim milk, and the two leave separately. Before these machines, milk sat in a container until the fat rose and could be skimmed by hand, sometimes going sour first.","inputs":["raw-milk"]},{"name":"Eject the bowl sediment","process":"wash","text":"Any solids in the milk gather as sediment in the separator bowl. Modern bowls throw this out by themselves, which lets the machine be cleaned in place without taking it apart.","inputs":[]},{"name":"Set the fat grade","process":"mix","text":"Fat level decides what the product can be called. In the United States, half and half holds 10.5 to 18 percent fat, light cream 18 to 30, and heavy cream at least 36. Skim is blended back until the batch lands in its band.","inputs":[]},{"name":"Heat-treat the batch","process":"pasteurize","text":"The cream is pasteurized or sterilized at ultra-high temperature to kill microbes and extend its life. French rules allow the words crème fraîche only on pasteurized cream packed on site within 24 hours.","inputs":[]},{"name":"Fill and keep cold","process":"fill","text":"Chilled cream is filled into cartons or tubs and stays in the cold chain until sale. Some goes on to other dairy lines in tankers instead, to be churned or cultured.","inputs":[]}],"facts":["Cows on natural pasture can give faintly yellow cream, because separation concentrates carotenoid pigments from the plants they eat.","Whisking turns cream into a soft solid only when it holds more than 30% fat.","Goats and water buffalo give pure white cream."],"where":[],"whereNote":null,"sources":[{"title":"Cream","url":"https://en.wikipedia.org/wiki/Cream"},{"title":"Butterfat","url":"https://en.wikipedia.org/wiki/Butterfat"},{"title":"Cream separator","url":"https://en.wikipedia.org/wiki/Cream_separator"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cream-cheese","name":"Cream cheese","kind":"product","category":"food","title":"How cream cheese is made","url":"https://assemblyline.org/make/cream-cheese","stations":7,"upstream":5,"downstream":0,"depth":2,"dek":"Cream cheese is never aged. The whole job is stopping the bacteria at exactly the right minute.","answer":"Cream cheese starts as pasteurized, homogenized milk and cream that lactic bacteria sour until the proteins clump into curd. Heat then kills the bacteria at precisely the right moment, the whey is drained off, and the curd is blended with salt and stabilizers into a smooth mass. It is packed fresh and never matured.","aka":["soft cheese spread","queso filadelfia"],"inputs":["raw-milk","cream","table-salt"],"uses":[],"grounds":["raw-milk","rock-salt","seawater"],"upstreamSlugs":["raw-milk","cream","table-salt","rock-salt","seawater"],"downstreamSlugs":[],"steps":[{"name":"Blend milk with cream","process":"mix","text":"Milk and extra cream are combined so the finished cheese lands above the legal fat floor. In the United States that floor is 33 percent milk fat, and the cheese may hold no more than 55 percent moisture.","inputs":["raw-milk","cream"],"spec":"at least 33% milk fat"},{"name":"Heat and shake the fat apart","process":"pasteurize","text":"The blend is pasteurized and homogenized. Homogenizing smashes the fat into tiny droplets so they stay spread through the cheese instead of floating to the top.","inputs":[]},{"name":"Sour it with bacteria","process":"ferment","text":"Lactic acid bacteria go into the warm blend and feed on milk sugar. As the acid builds, the proteins lose their surface charge, stop repelling each other and the liquid sets into a soft curd.","inputs":[],"spec":"about 22 °C"},{"name":"Kill the culture on cue","process":"cook","text":"The curd has to be heated at the moment the proteins are electrically balanced. Wait too long and the acid keeps rising, the proteins flip charge and the mass turns liquid again. Mistime it and the flavor and texture go wrong.","inputs":[],"spec":"52 to 63 °C"},{"name":"Drain off the whey","process":"separate","text":"The liquid whey is removed from the heated curd, leaving a thick mass. This is where a factory needs help, because fat repels water and the water tends to creep back out and pool.","inputs":[]},{"name":"Fold in salt and gums","process":"mix","text":"Salt goes into the curd along with a small amount of stabilizer such as carob bean gum, guar gum, carrageenan or xanthan gum. The gum holds water inside the cheese and extends its shelf life.","inputs":["table-salt"]},{"name":"Pack it fresh","process":"package","text":"The smooth mass is packed fresh, since cream cheese is not meant to be matured. Canadian rules also allow nitrogen to be worked in to help it spread.","inputs":[]}],"facts":["The name Philadelphia has nothing to do with the city. A New York cheese distributor picked it for the brand in 1880.","Cream cheese was first mass produced around 1873 by a dairyman in Chester, New York.","Timing the heat is so critical that a batch of cream cheese can fail simply because the bacteria were left in the milk a few minutes too long."],"where":[],"whereNote":null,"sources":[{"title":"Cream cheese","url":"https://en.wikipedia.org/wiki/Cream_cheese"},{"title":"Cheese","url":"https://en.wikipedia.org/wiki/Cheese"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"credit-card","name":"Credit card","kind":"product","category":"plastics","title":"How credit cards are made","url":"https://assemblyline.org/make/credit-card","stations":7,"upstream":80,"downstream":0,"depth":9,"dek":"A credit card is a laminated sandwich of printed plastic sheets, cut out of a big sheet in one stroke.","answer":"Cards are printed in big sheets, not one at a time. PVC core sheets run through offset or screen presses, then machines stack them with overlays that already carry the magnetic stripe. Heat and pressure fuse the stack, and an optically guided die punches out each card. A hologram, signature panel and chip are added before personalization.","aka":["payment card","bank card","debit card"],"inputs":["pvc","ink","pet-plastic","microchip","adhesive"],"uses":[],"grounds":["water","natural-gas","rock-salt","iron-ore","sulfur","air","soybeans","rapeseed","clay","crude-oil","titanium-ore","corn","sugarcane","quartz","tin-ore","copper-ore","coal","gold-ore","limestone","bauxite","zinc-ore","sugar-beet","timber"],"upstreamSlugs":["pvc","ink","pet-plastic","microchip","adhesive","ethylene","chlorine","water","pigment","plasticizer","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","ethanol","p-xylene","ethylene-glycol","silicon-wafer","oxygen","photoresist","tin","copper","aluminum","gold","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","naphtha","natural-gas","rock-salt","sulfuric-acid","iron-ore","sulfur","air","propylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","titanium-ore","coke","corn","sugarcane","yeast","carbon-dioxide","polysilicon","quartz","argon","tin-ore","copper-ore","coal","petroleum-coke","alumina","gold-ore","lime","zinc","ammonia","methanol","acetone","caustic-soda","nitric-acid","hydrogen","benzene","molasses","limestone","silicon","hydrochloric-acid","trichlorosilane","nitrogen","bauxite","zinc-ore","toluene","sugar-beet","charcoal","timber"],"downstreamSlugs":[],"steps":[{"name":"Print the core sheets","process":"print","text":"Thin PVC core sheets, often split into two layers about .013 inches thick, run through offset or screen presses. Cyan, magenta, yellow and black combine into the image, and fiducial marks are printed for later alignment. Digital printing handles short runs.","inputs":["pvc","ink"]},{"name":"Collate with overlays","process":"assemble","text":"Machines stack front and back sheets by optical registration and add clear overlay films. Those overlays protect against scratches and sunlight, and the back one already carries the magnetic stripe.","inputs":["pvc"]},{"name":"Laminate under heat","process":"laminate","text":"The stack goes into a heating tower, then transfers automatically to a cooling tower under pressure. What once took hours now takes minutes, and it fuses layers and stripe into one slab.","inputs":[]},{"name":"Shear and punch","process":"stamp","text":"The slab is sheared down, then a male and female die, guided by cameras reading the printed marks, punches out each card with rounded corners.","inputs":[]},{"name":"Add hologram and panel","process":"laminate","text":"After inspection, a hologram of metallized polyester and a signature panel go on the surface.","inputs":["pet-plastic"]},{"name":"Mill and embed the chip","process":"machine","text":"A cutter mills a shallow cavity in the finished card and a chip module is glued into it.","inputs":["microchip","adhesive"]},{"name":"Personalize and ship","process":"print","text":"The cardholder's name and number are added and the stripe and chip are encoded. Fulfillment attaches the card to its mailer.","inputs":[]}],"facts":["In 1959, American Express was the first charge card operator to issue embossed plastic cards, which made manual imprinting faster and reduced errors.","In 1972, Lloyds Bank issued the first bank card with an information-encoding magnetic strip and a PIN."],"where":[],"whereNote":null,"sources":[{"title":"Plastics Decorating: The card market, an introduction to process and materials","url":"https://plasticsdecorating.com/?p=813"},{"title":"ICMA: Card manufacturing, an ongoing evolution","url":"https://icma.com/card-manufacturing-an-ongoing-evolution"},{"title":"Payment card","url":"https://en.wikipedia.org/wiki/Payment_card"},{"title":"Polyvinyl chloride","url":"https://en.wikipedia.org/wiki/Polyvinyl_chloride"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cricket-bat","name":"Cricket bat","kind":"product","category":"play","title":"How cricket bats are made","url":"https://assemblyline.org/make/cricket-bat","stations":7,"upstream":33,"downstream":0,"depth":8,"dek":"Willow is so soft that bat makers squeeze it hard before shaping, and listen to the fibers creak.","answer":"A cricket bat blade is cut from a willow tree grown for 15 to 20 years. The trunk is sawn into lengths, split into clefts, dried and compressed under pressure to harden the soft wood. A cane handle is spliced in, and the bat is shaped, sanded and polished.","aka":["willow bat","english willow bat"],"inputs":["timber","adhesive","rubber"],"uses":[],"grounds":["timber","water","natural-latex","sulfur","crude-oil","air","natural-gas","rock-salt","coal"],"upstreamSlugs":["timber","adhesive","rubber","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","natural-latex","synthetic-rubber","carbon-black","sulfur","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","naphtha","benzene","styrene","air","natural-gas","rock-salt","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Fell and cut the willow","process":"harvest","text":"The cricket bat willow, Salix alba var. caerulea, is grown for 15 to 20 years. The butt of the trunk is cut into 29-inch lengths at the yard.","inputs":["timber"]},{"name":"Split into clefts","process":"cut","text":"Each length is split into clefts, the rough planks that each make one bat. The splitter wants as many clefts per round as possible, and sees the first sign of knots, stains and flaws.","inputs":[]},{"name":"Dry the clefts","process":"dry","text":"Clefts are stacked and left to dry. Counting drying time, the full trip from tree to finished bat takes between 2 and 3 months at Gray-Nicolls.","inputs":[]},{"name":"Compress the blade","process":"press","text":"A press squeezes the willow, and you can hear the fibers tension. Willow is very soft, and without this compression the bat would never send a ball far. Wood that takes the squeeze well makes a better bat.","inputs":[]},{"name":"Splice in the handle","process":"assemble","text":"The top of the blade is slit and a cane handle is glued into the gap. This tapered splice dates from the 1880s, and the handle usually wears a rubber grip.","inputs":["adhesive","rubber"]},{"name":"Shape the blade","process":"machine","text":"The blade is profiled with edges, a spine ridge on the back and a toe. Many makers use a CNC machine for the outline and refine it by hand.","inputs":[]},{"name":"Balance, sand and polish","process":"grind","text":"A final bat maker shapes the bat for balance, then sands and polishes it. The finished bat still needs knocking in with an old ball or mallet to compact the soft fibers.","inputs":[]}],"facts":["Cricket bats are rubbed with raw linseed oil because raw oil dries very slowly and the surface stays tacky.","Kashmir willow and English willow are the same species, though English willow bats sell for more.","In 2005 one maker added a carbon fiber strip down the spine of a bat and it was ruled illegal under the laws of cricket."],"where":[],"whereNote":null,"sources":[{"title":"The Art Of Batmaking","url":"https://www.gray-nicolls.co.uk/blogs/the-game/the-art-of-batmaking"},{"title":"Cricket bat","url":"https://en.wikipedia.org/wiki/Cricket_bat"},{"title":"Our Craft","url":"https://coopercricket.com.au/pages/our-craft"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"croissant","name":"Croissant","kind":"product","category":"food","title":"How croissants are made","url":"https://assemblyline.org/make/croissant","stations":7,"upstream":32,"downstream":0,"depth":9,"dek":"A croissant is a bread dough folded around butter so many times that it bakes into hundreds of flaky sheets.","answer":"Yeast dough is rolled out, covered with a slab of butter and folded repeatedly, a technique called laminating. The folded sheet is cut into triangles that are rolled into crescents, proofed until puffy and baked. Steam from the butter and dough pushes the layers apart. Many factories freeze the shaped dough for bakeries.","aka":["butter croissant","viennoiserie","crescent roll"],"inputs":["flour","water","yeast","sugar","table-salt","pasteurized-milk","butter"],"uses":[],"grounds":["water","wheat","sugarcane","sugar-beet","rock-salt","seawater","raw-milk","air","limestone","corn","natural-gas","crude-oil"],"upstreamSlugs":["flour","water","yeast","sugar","table-salt","pasteurized-milk","butter","wheat","vitamin-c","molasses","sugarcane","sugar-beet","lime","rock-salt","seawater","raw-milk","cream","corn-starch","hydrogen","air","plastic-bottle","limestone","corn","natural-gas","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Mix the base dough","process":"mix","text":"Flour, water, yeast, sugar, salt and a little butter or milk make a dough that is soft but not too elastic. It rests in the cold so the yeast does not run ahead.","inputs":["flour","water","yeast","sugar","table-salt","pasteurized-milk"]},{"name":"Lock in the butter","process":"laminate","text":"A flat slab of cold butter is placed on the sheet of dough and sealed inside like an envelope. The butter has to stay cool enough to stay solid but soft enough to roll without cracking.","inputs":["butter"]},{"name":"Roll and fold repeatedly","process":"roll","text":"The dough and butter are rolled together into a long sheet and folded in thirds, again and again, with rests in between. Each fold multiplies the number of alternating layers of dough and fat.","inputs":[]},{"name":"Cut into triangles","process":"cut","text":"The thin laminated sheet is sliced into long triangles by a rotary cutter, with almost no waste.","inputs":[]},{"name":"Roll them up","process":"mold","text":"Each triangle is rolled from the wide edge toward the tip and curved into a crescent. Machines on the line do this at high speed.","inputs":[]},{"name":"Proof until puffy","process":"ferment","text":"The crescents sit in a warm room while yeast makes gas. The layers swell, but the room must not be hot enough to melt the butter out.","inputs":[]},{"name":"Bake until golden","process":"bake","text":"Water in the dough and butter turns to steam in the oven and lifts each layer apart. Melted butter fries the layers crisp, and the surface browns. Factory lines freeze unbaked croissants so shops can bake them fresh.","inputs":[]}],"facts":["The first recipe corresponding to the modern croissant was published in Paris in 1906.","In the late 1970s, frozen unbaked dough let unskilled staff bake croissants fresh, and a French fast-food chain was built around them.","Austrian officer August Zang opened a Viennese bakery in Paris in 1838 or 1839 that helped popularize the kipferl, the croissant's ancestor."],"where":[],"whereNote":null,"sources":[{"title":"Croissant","url":"https://en.wikipedia.org/wiki/Croissant"},{"title":"Bread","url":"https://en.wikipedia.org/wiki/Bread"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"crude-oil","name":"Crude oil","kind":"raw","category":"ground","title":"How crude oil is drilled","url":"https://assemblyline.org/make/crude-oil","stations":4,"upstream":0,"downstream":492,"depth":0,"dek":"The earliest known oil wells were drilled in China in 347 CE with bits hung on bamboo poles.","answer":"Crude oil is the thick, dark remains of ancient plankton and algae, trapped in rock deep underground. A drilling rig spins a steel bit down through the layers, and steel pipe called casing is cemented into the hole as it deepens. When the well reaches the oil, pressure and pumps bring it up to the surface.","aka":["petroleum","oil"],"inputs":[],"uses":["sunscreen","detergent","naphtha","gasoline","diesel","jet-fuel","asphalt","propylene","carbon-black","synthetic-graphite","paraffin-wax","aluminum","hexane","propane","motor-oil","petroleum-coke","pentane"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["sunscreen","detergent","naphtha","gasoline","diesel","jet-fuel","asphalt","propylene","carbon-black","synthetic-graphite","paraffin-wax","aluminum","hexane","propane","motor-oil","petroleum-coke","pentane","ethylene","polystyrene","abs-plastic","synthetic-rubber","benzene","p-xylene","plastic","toluene","plasticizer","car","car-engine","motorcycle","locomotive","airplane","jet-engine","road","roof-shingle","polypropylene","acrylic","polycarbonate","epoxy","polyurethane","carbon-fiber","phenol","pvb","acrylic-acid","acetone","mascara","rubber","ink","aa-battery","tire","hockey-puck","tungsten-carbide","printer-toner","hiking-boots","rubber-boots","vinyl-record","remote-control","pigment","lithium-ion-cell","synthetic-diamond","deodorant","lipstick","adhesive","pencil","chewing-gum","turbine-blade","crayon","candle","cork-stopper","golf-club","eyeshadow","dental-floss","mdf","match","microchip","led-bulb","oled-screen","ev-battery","smartphone","laptop","hard-drive","solid-state-drive","solar-cell","solar-panel","refrigerator","washing-machine","satellite","aluminum-foil","brass","cobalt","chromium","nonstick-pan","aluminum-can","mirror","skyscraper","electric-car","rocket","bicycle","skateboard","drum-kit","pencil-eraser","pressure-cooker","toaster","air-conditioner","ceiling-fan","office-chair","ski","yo-yo","toy-car","asthma-inhaler","prosthetic-leg","wheelchair","ladder","double-glazed-window","aluminum-window-frame","subway-train","sailboat","suitcase","smartwatch","microphone","camera-lens","compact-disc","game-console","graphics-card","vanadium","newspaper","zipper","n95-mask","vegetable-oil","steel-scrap","refrigerant","air-freshener","hairspray","polystyrene-foam","foam-cup","shampoo","polyethylene","pvc","pet-plastic","ethanol","styrene","polyvinyl-alcohol","ethylene-glycol","surfboard","bike-helmet","ballpoint-pen","smoke-detector","inkjet-printer","hearing-aid","thermometer","lego-brick","3d-printer-filament","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","snowboard","action-figure","harmonica","globe","high-heels","wireless-earbuds","phone-charger","usb-cable","wifi-router","e-reader","electric-toothbrush","toothbrush","syringe","nitrile-glove","golf-ball","basketball","flip-flops","nylon","spandex","kevlar","duct-tape","led","vacuum-cleaner","marker-pen","highlighter","fountain-pen","roller-skates","tennis-racket","bowling-ball","dice","board-game","jigsaw-puzzle","trading-cards","snow-globe","tampon","wet-wipes","light-switch","power-outlet","seat-belt","backpack","eyeglass-frame","umbrella","nail-polish","yoga-mat","vinyl-floor","cellulose-acetate","electric-kettle","plastic-straw","clear-tape","dishwasher","frisbee","sanitary-pad","cotton-swab","car-battery","loudspeaker","baseball-cap","carpet","rope","diaper","paint","lcd-screen","sunglasses","lacquer","drone","eyeglass-lens","blender","digital-camera","printed-circuit-board","wind-turbine","electric-motor","rebar","fishing-rod","adhesive-bandage","pacemaker","soccer-ball","hardwood-floor","water-heater","sofa","volleyball","underwear","leggings","swimsuit","raincoat","sneaker","mattress","kite","aspirin","acetaminophen","billiard-ball","brake-pad","phenolic-resin","windshield","superabsorbent-polymer","shoelace","shipping-container","tennis-ball","baseball","football","cricket-bat","dumbbell","treadmill","wheelbarrow","fire-extinguisher","leather-shoe","plastic-bag","credit-card","tin-can","paper-cup","pizza-box","wallpaper","laminate-floor","candy-coated-chocolate","floor-tile","flag","cardboard-box","book","sticky-notes","playing-cards","banknote","t-shirt","saw-blade","porcelain","chalk","candy-cane","sprinkles","foundation-makeup","towel","nail","insulation","popcorn","guitar","piano","violin","paper-straw","paper-bag","wooden-chair","door","staple","ice-skates","dartboard","chess-set","ukulele","cello","drumstick","pinball-machine","kitchen-sponge","dress-shirt","suit","handbag","wallet","plywood","cardboard","toilet-paper","envelope","champagne","airbag","toothpaste","condom","wristwatch","faucet","padlock","electric-guitar","trumpet","garden-hose","saxophone","guitar-string","hinge","key","gas-cylinder","leather-belt","hip-implant","stent","stainless-steel","safety-pin","razor-blade","wrench","nichrome","leather","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","down-jacket","jeans","soap","glycerin","cast-iron-pan","margarine","mayonnaise","peanut-butter","tortilla","donut","sandwich-cookie","potato-chips","french-fries","canned-tuna","chicken-nuggets","baby-formula","oat-milk","crackers","fish-sticks","biodiesel","wooden-spoon","modeling-clay","cake-mix","steel","glass-bottle","frozen-peas","bubble-wrap","plastic-wrap","zip-bag","thermos","power-cable","fashion-doll","inflatable-pool-toy","chain-link-fence","pvc-pipe","polyester","plastic-bottle","bottled-water","perfume","vaccine","vanilla-extract","vinegar","gin","super-glue","port-wine","mouthwash","velcro","socks","canoe","microwave-oven","scissors","container-ship","water-bottle","coil-spring","hammer","neon-sign","suspension-bridge-cable","chopsticks","felt-hat","baseball-bat","elevator","concrete","photoresist","cotton-candy","pillow","condensed-milk","coconut-milk","canned-meat","canned-soup","paperclip","corn-flakes","fireworks","salsa","cough-syrup","facial-tissue","hair-dye","kitchen-knife","fork","winter-gloves","gelatin-capsule","transformer","sheet-steel","tinplate","steel-wire","steel-beam","rail","steel-pipe","ball-bearing","wine-barrel","barbed-wire","drill-bit","stained-glass","spark-plug","penicillin","insulin","ketchup","wine","whiskey","vodka","rum","tequila","sake","hot-sauce","kombucha","bourbon","scotch","cognac","mezcal","mead","prosecco","hoodie","curtain","button","thread","teddy-bear","bleach","vitamin-c","dish-soap","ice-cream","white-chocolate","caramel","mustard","pickles","memory-chip","indium-tin-oxide","toffee","shovel","wire-rope","screw","needle","clothespin","slinky","bolt","chain","silk-tie","blanket","sweater","flour","bread","instant-noodles","croissant","pretzel","frozen-pizza","bagel","baguette","sourdough","licorice"],"steps":[{"name":"Pick the target","process":"mine","text":"Geoscientists and engineers work out what rock the well will pass through and where the oil should sit. They plan the path so that the bit meets the reservoir without hitting zones that would be unsafe to drill.","inputs":[]},{"name":"Spin the bit down","process":"drill","text":"A rig rotates a long string of pipe with a bit on the end, boring a hole from 12 centimeters up to 1 meter wide. Modern directional drilling lets a well turn from vertical and run sideways through a thin layer of oil-bearing rock.","inputs":[]},{"name":"Case and cement the hole","process":"drill","text":"At set depths, sections of steel pipe slightly smaller than the hole are lowered in and cemented into place. Each casing isolates the rock behind it, and the well can then continue deeper with a smaller bit.","inputs":[]},{"name":"Bring it to the surface","process":"drill","text":"Oil rises on its own pressure at first and is lifted with pumps later. Some natural gas usually comes up with it, and the oil is sent off to be refined.","inputs":[]}],"facts":["An estimated 70% of the world's oil deposits formed in the Mesozoic era.","Edwin Drake drilled a famous early oil well in Pennsylvania in 1859."],"where":[],"whereNote":null,"sources":[{"title":"Petroleum","url":"https://en.wikipedia.org/wiki/Petroleum"},{"title":"Oil well","url":"https://en.wikipedia.org/wiki/Oil_well"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cucumber","name":"Cucumber","kind":"raw","category":"farm","title":"How cucumbers are grown","url":"https://assemblyline.org/make/cucumber","stations":4,"upstream":0,"downstream":1,"depth":0,"dek":"Farmers truck thousands of beehives into the fields each year. The fruit that results is 95% water.","answer":"A cucumber is the fruit of a creeping vine that climbs with thin, spiraling tendrils. Most kinds need pollen moved between plants, so beehives are hauled to the fields just before bloom. Fruit is picked young, while still green. Short, thick, thin-skinned types go off for pickling, and longer ones head for the salad counter.","aka":["pickling cucumber","gherkin","Cucumis sativus"],"inputs":[],"uses":["pickles"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["pickles"],"steps":[{"name":"Plant the vines","process":"grow","text":"The cucumber is an annual vine with among the highest heat needs of common vegetables. It grows up trellises or sprawls over the ground, and uneven watering can make the fruit bitter.","inputs":[]},{"name":"Truck in the bees","process":"grow","text":"Most seeded varieties cannot pollinate themselves, so thousands of honey beehives are carried to the fields just before bloom. Newer hybrids make almost all female flowers, and need more hives per acre.","inputs":[]},{"name":"Grow under the canopy","process":"grow","text":"Large leaves form a canopy over the developing fruit and shade it. Greenhouse growers often use varieties that set seedless fruit with no pollination at all.","inputs":[]},{"name":"Pick them young","process":"harvest","text":"Fruit is taken while still immature. Pickling types are shorter, thicker and thinner-skinned than slicers, and gherkins are gathered at just 2.5 to 12.5 centimeters long.","inputs":[]}],"facts":["Cucumbers have been cultivated for at least 3,000 years, and the Roman Emperor Tiberius ate them all year round.","Raw cucumber is 95% water.","World production of cucumbers and gherkins reached 88 million tonnes in 2024."],"where":[{"place":"China","share":"78% of world output"}],"whereNote":"2024 world production of cucumbers and gherkins, as quoted on Wikipedia.","sources":[{"title":"Cucumber","url":"https://en.wikipedia.org/wiki/Cucumber"},{"title":"Cucumber (Britannica)","url":"https://www.britannica.com/plant/cucumber"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cultured-pearl","name":"Cultured pearl","kind":"product","category":"hardware","title":"How cultured pearls are made","url":"https://assemblyline.org/make/cultured-pearl","stations":6,"upstream":2,"downstream":0,"depth":1,"dek":"The bead inside a Tahitian pearl is cut from freshwater mussel shell, and the best shells come from the Mississippi.","answer":"Pearl farmers raise oysters for years, then open each one and insert a polished shell bead beside a scrap of mantle tissue from a donor. The tissue grows into a sac around the bead and coats it in layer after layer of nacre. Two years later, the pearls are harvested, sorted, drilled and strung.","aka":["farmed pearl","akoya pearl"],"inputs":["pearl-oyster","seawater"],"uses":[],"grounds":["pearl-oyster","seawater"],"upstreamSlugs":["pearl-oyster","seawater"],"downstreamSlugs":[],"steps":[{"name":"Raise the young oysters","process":"grow","text":"Larvae settle on plastic lines in a lagoon and move to underwater stations, where they are scraped clean of hitchhikers several times a year. After about three years they are big enough to graft.","inputs":["pearl-oyster"],"spec":"10-12 centimeters across"},{"name":"Carve the seed beads","process":"grind","text":"Beads are cut and polished into spheres from freshwater mussel shell. Each bead will become the center of a pearl.","inputs":[]},{"name":"Graft the oyster","process":"assemble","text":"A technician opens the oyster and sets a polished bead and a small piece of donor mantle tissue side by side in its gonad. The tissue's outer cells multiply and spread over the bead to form a pearl sac.","inputs":[]},{"name":"Hang them in the water","process":"grow","text":"Back in the sea, the oysters sit in nets or cages while the sac lays down thin coats of nacre, the same material that lines the inside of the shell.","inputs":["seawater"]},{"name":"Open and harvest","process":"harvest","text":"After about two years, workers open the oyster and take out the pearl. A healthy oyster may receive a new bead the same size as the pearl it just gave up, with no new tissue needed.","inputs":[]},{"name":"Sort and string","process":"inspect","text":"Pearls are washed, polished and sorted by size, shape, color and luster, then drilled and strung into necklaces.","inputs":[]}],"facts":["More than 99% of all pearls sold worldwide are cultured pearls.","A Tahitian pearl harvest comes about 5 years after the oyster first settles as a larva.","An oyster that has given up a good pearl can be regrafted at once, with a bead as big as that pearl and no new tissue."],"where":[],"whereNote":null,"sources":[{"title":"Cultured pearl","url":"https://en.wikipedia.org/wiki/Cultured_pearl"},{"title":"Pearl","url":"https://en.wikipedia.org/wiki/Pearl"},{"title":"Pearl Oyster Farming and Pearl Culture: Pearl Formation","url":"https://www.fao.org/4/AB726E/AB726E11.htm"},{"title":"Our pearl farming process","url":"https://www.robertwan.com/the-5-steps-of-pearl-farming"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"curtain","name":"Curtains","kind":"product","category":"textiles","title":"How curtains are made","url":"https://assemblyline.org/make/curtain","stations":8,"upstream":22,"downstream":0,"depth":8,"dek":"A pleating machine can work out how many folds a curtain gets from the cloth length typed into it.","answer":"Curtain cloth arrives on rolls and, in an automated plant, unwinds onto a table that spreads it flat and cross-cuts up to 4 layers at once. Rotary blades trim the selvedge, sewing heads run continuous hems, and a multi-needle machine folds evenly spaced pleats. Heading tape feeds in from a roller and is stitched across the back.","aka":["drapes","window curtains","blackout curtains"],"inputs":["polyester","cotton-yarn","thread"],"uses":[],"grounds":["raw-cotton","water","natural-gas","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["polyester","cotton-yarn","thread","pet-plastic","raw-cotton","water","p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","oxygen","carbon-dioxide","crude-oil","hydrogen","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Unwind the rolls","process":"cut","text":"Cloth comes in everything from silk to polyester to warp knit, often a cotton and polyester blend. An unwinder feeds up to 4 rolls at low tension while a motorized aligner keeps them square to the machine.","inputs":["polyester","cotton-yarn"]},{"name":"Cross-cut the lengths","process":"cut","text":"An automatic table spreads the cloth and cuts it across, handling up to 4 layers at a time and widths up to 3.2 meters. A touch screen sets the length, speed and number of cuts.","inputs":[]},{"name":"Slit the selvedge","process":"cut","text":"A lengthwise model uses 3 rotating blades to trim the woven edge and split the cloth along its length, cutting right along a thread.","inputs":[]},{"name":"Hem the long edges","process":"sew","text":"Automatic units cut to length and hem in one continuous run. One drapery machine sews a decorative open stitch along cloth up to 900 mm wide.","inputs":["thread"],"spec":"up to 2 meters per minute on one hemming unit"},{"name":"Fold in the pleats","process":"sew","text":"A multi-needle machine run by a programmable controller forms single or double pleats. Told the cloth length and finished width, it calculates how many folds to make, and a button switches the pleat type.","inputs":["thread"],"spec":"maximum 700 RPM on one pleater"},{"name":"Stitch on heading tape","process":"assemble","text":"A roller under the table feeds tape to the back of the pleated cloth, where it is stitched down. Wide-gauge machines handle 65 mm tape on cotton or velvet.","inputs":["thread"]},{"name":"Tack the corners","process":"sew","text":"An automatic machine sews small hidden tacks at the corners, and a binding attachment makes matching tie-backs from strips of cloth.","inputs":["thread"]},{"name":"Fold and pack","process":"package","text":"Home furnishing lines end by folding and packaging the finished pieces.","inputs":[]}],"facts":["Medieval English window coverings started as leather panels threaded onto iron rods.","Mosaics from the second to sixth century show curtains hung from rods across arches."],"where":[],"whereNote":null,"sources":[{"title":"Home Furnishing Specialized Technology for Manufacturing, Apparel Resources","url":"https://in.apparelresources.com/technology-news/manufacturing-tech/home-furnishing-specialized-technology-manufacturing"},{"title":"Curtain","url":"https://en.wikipedia.org/wiki/Curtain"},{"title":"Polyester","url":"https://en.wikipedia.org/wiki/Polyester"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cut-diamond","name":"Cut diamond","kind":"product","category":"hardware","title":"How diamonds are cut","url":"https://assemblyline.org/make/cut-diamond","stations":6,"upstream":1,"downstream":0,"depth":1,"dek":"A diamond can only be polished with other diamonds, and the usual round gem has 57 facets.","answer":"Software maps a rough diamond so cutters can plan the best stones. It is split by cleaving, saw or laser, then two diamonds spin in opposite directions and grind each other round. On a spinning wheel, blockers add the 18 main facets and brillianteers add the rest, for 57 in all. The finished gem is inspected and sent for grading.","aka":["brilliant cut diamond","polished diamond","gem diamond"],"inputs":["rough-diamond"],"uses":[],"grounds":["rough-diamond"],"upstreamSlugs":["rough-diamond"],"downstreamSlugs":[],"steps":[{"name":"Scan and plan","process":"inspect","text":"A cutter studies the rough, today with software that builds a 3D model and shows the best ways to divide it. Sometimes several gems come from one crystal.","inputs":["rough-diamond"]},{"name":"Cleave, saw or laser","process":"cut","text":"The stone is split along its natural grain or sawn with a blade coated in diamond dust. Lasers handle awkward shapes without touching it.","inputs":[]},{"name":"Brute the girdle","process":"grind","text":"Two diamonds sit on spinning axles turning in opposite directions and grind against each other, giving each a rough round outline. This stage is also called girdling.","inputs":[]},{"name":"Block the main facets","process":"grind","text":"Held on a rotating arm against a spinning wheel, the stone receives 8 pavilion mains, 8 crowns, 1 culet and 1 table, which form a template for the rest.","inputs":[]},{"name":"Brillianteer the rest","process":"grind","text":"A specialist adds the remaining facets for a total of 57, polishing on wheels charged with diamond powder. The stone's fire is set here.","inputs":[]},{"name":"Inspect and grade","process":"inspect","text":"The polished gem is checked for finish and proportion, then goes to a lab such as GIA for a grading report.","inputs":[]}],"facts":["Diamond can only be polished by means of other diamonds.","Cutting and polishing a rough diamond costs about 50% of its weight, even with modern techniques.","India has in recent years held around 90% of the world market in polished diamonds."],"where":[],"whereNote":null,"sources":[{"title":"Beyond4Cs: How are diamonds cut and polished from roughs?","url":"https://beyond4cs.com/cut/how-diamonds-are-polished/"},{"title":"Diamond cut","url":"https://en.wikipedia.org/wiki/Diamond_cut"},{"title":"Diamond","url":"https://en.wikipedia.org/wiki/Diamond"},{"title":"Diamond cutting","url":"https://en.wikipedia.org/wiki/Diamond_cutting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"dartboard","name":"Dartboard","kind":"product","category":"play","title":"How dartboards are made","url":"https://assemblyline.org/make/dartboard","stations":7,"upstream":71,"downstream":0,"depth":10,"dek":"A dartboard is a plant fiber pressed so hard that it closes up around each dart hole.","answer":"Most dartboards are built from sisal, a stiff fiber stripped from agave leaves. The fibers are braided into bundles, formed into tubes, sliced into wafers and pressed into a disc on a backboard. The surface is sanded, painted, and divided into scoring segments by thin metal wire.","aka":["dart board","bristle dartboard","sisal dartboard"],"inputs":["agave","adhesive","paint","steel-wire"],"uses":[],"grounds":["agave","water","crude-oil","titanium-ore","iron-ore","sulfur","natural-gas","air","rock-salt","coal","limestone","dolomite","manganese-ore","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","quartz","timber","sugar-beet"],"upstreamSlugs":["agave","adhesive","paint","steel-wire","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","titanium-dioxide","pigment","tin-can","steel","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","titanium-ore","coke","oxygen","iron-ore","carbon-black","sulfur","tinplate","lacquer","ink","pig-iron","magnesium","steel-scrap","lime","manganese","argon","naphtha","natural-gas","air","benzene","rock-salt","coal","tin","ethanol","vegetable-oil","phenolic-resin","limestone","dolomite","silicon","propane","manganese-ore","toluene","tin-ore","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","formaldehyde","quartz","charcoal","timber","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Strip the sisal leaves","process":"harvest","text":"Sisal is a stiff, tough fiber from the Agave sisalana plant, the same genus that gives us tequila. A machine strips the skin off the leaves so only the strong fibers remain.","inputs":["agave"]},{"name":"Dry and brush the fiber","process":"dry","text":"The stripped fibers are dried and brushed straight. A good board needs fibers that are uniform and stiff, which is why sisal beat horse hair in practice.","inputs":[]},{"name":"Braid into bundles","process":"spin","text":"Fibers are braided into long bundles, and the bundles are formed into tubes.","inputs":[]},{"name":"Slice into wafers and press","process":"press","text":"The tubes are cut into thin wafers, which are then pressed into a circular disc and secured to a backboard. Density sets how hard the board plays and how well it heals.","inputs":["adhesive"]},{"name":"Sand the face","process":"grind","text":"The face is sanded to remove the roughness of the raw fiber. How much is taken off changes how well the board closes up around holes, so it also changes how long the board lasts.","inputs":[]},{"name":"Paint the segments","process":"print","text":"The red, green and black colors go on in a low-glare paint, so a bright reflection does not distract a thrower.","inputs":["paint"]},{"name":"Press in the wire web","process":"assemble","text":"Thin wire divides the board into scoring sections. Traditional boards fix this web with more than 40 staples, and each staple is a place where a dart can bounce out. Staple-free designs use thinner wire that deflects darts into the segments.","inputs":["steel-wire"]}],"facts":["Pub boards were solid elm until World War I, and had to be soaked every night so the dart holes swelled shut by morning.","Horse hair dartboards are a myth: animal bristles were never used, and sisal only looks like them.","The first sisal boards came from a British company, partly because wooden boards had an unpleasant smell."],"where":[],"whereNote":null,"sources":[{"title":"What Is A Dartboard Made Of?","url":"https://darthelp.com/articles/what-is-a-dartboard-made-of/"},{"title":"Winmau Blade Evolution","url":"https://winmau.com/news/post/winmau-blade-evolution"},{"title":"Dartboard","url":"https://en.wikipedia.org/wiki/Dartboard"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"decaf-coffee","name":"Decaf coffee","kind":"product","category":"drink","title":"How decaf coffee is made","url":"https://assemblyline.org/make/decaf-coffee","stations":7,"upstream":10,"downstream":0,"depth":4,"dek":"Caffeine is removed while the beans are still green, so the roaster never sees it.","answer":"Decaffeination happens before roasting. Green beans are steamed, then washed with water, a liquid solvent, or pressurized carbon dioxide until most of the caffeine has dissolved away. The beans are dried and then roasted as usual. In the US, at least 97% of the caffeine must be removed before the coffee can be called decaffeinated.","aka":["decaffeinated coffee","decaf","swiss water decaf"],"inputs":["coffee-cherries","water","carbon-dioxide"],"uses":[],"grounds":["coffee-cherries","water","natural-gas","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["coffee-cherries","water","carbon-dioxide","natural-gas","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Steam the green beans","process":"cook","text":"Hard, dry green beans are steamed to open their pores. Caffeine is trapped deep inside the bean, and it will not escape until the bean is swollen and wet.","inputs":["coffee-cherries"]},{"name":"Soak in hot water","process":"wash","text":"In the indirect solvent and Swiss Water routes, the beans are first soaked in hot water for several hours. The water pulls out caffeine and many other flavor compounds.","inputs":["water"]},{"name":"Pull the caffeine out","process":"separate","text":"Caffeine is removed from the beans or from the soaking water using a liquid solvent such as ethyl acetate, an activated charcoal filter, or high-pressure carbon dioxide. Caffeine dissolves into the carrier, while the flavor compounds mostly stay put.","inputs":["carbon-dioxide"],"spec":"300 atm and 65 °C for supercritical CO2"},{"name":"Repeat until almost gone","process":"separate","text":"Solvent routes run the cycle over and over. Each pass leaves less caffeine in the bean until the batch tests clean.","inputs":[],"spec":"8 to 12 rinses"},{"name":"Steam off the carrier","process":"dry","text":"Beans are steamed again to drive off leftover solvent, then dried back to normal moisture. They are brownish gray and still unroasted.","inputs":[]},{"name":"Test the caffeine left","process":"inspect","text":"Labs measure the residual caffeine with liquid chromatography or near-infrared spectroscopy. A batch that misses the standard goes round again.","inputs":[]},{"name":"Roast like any other","process":"bake","text":"From here the beans are roasted, cooled and ground just like regular coffee. Roasting does not remove caffeine, which survives up to around 200 °C.","inputs":[]}],"facts":["The first commercial decaffeination process was invented by Ludwig Roselius in 1903 after a shipment of beans soaked in seawater lost most of its caffeine.","A 2006 study found decaffeinated drinks typically contained 1 to 2% of the original caffeine content.","One study found that fourteen to twenty cups of shop-bought decaf would hold as much caffeine as one regular cup.","A naturally caffeine-free coffee plant, Coffea charrieriana, was reported in 2004."],"where":[],"whereNote":null,"sources":[{"title":"Decaffeination","url":"https://en.wikipedia.org/wiki/Decaffeination"},{"title":"Coffee roasting","url":"https://en.wikipedia.org/wiki/Coffee_roasting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"denim","name":"Denim","kind":"material","category":"textiles","title":"How denim is made","url":"https://assemblyline.org/make/denim","stations":6,"upstream":4,"downstream":1,"depth":2,"dek":"Denim is blue on one side and white on the other, because only the lengthwise threads are dyed.","answer":"Denim is a twill cloth woven with indigo-dyed warp yarns and undyed weft. The warp yarn is dipped in indigo vats and exposed to air to turn blue, rewound onto beams, and woven so the warp mostly covers the face. The finished cloth is sanforized to limit shrinkage and rolled up in bolts.","aka":["blue denim","jean fabric","selvedge denim"],"inputs":["cotton-yarn","indigo-plant","water"],"uses":["jeans"],"grounds":["indigo-plant","water","raw-cotton"],"upstreamSlugs":["cotton-yarn","indigo-plant","water","raw-cotton"],"downstreamSlugs":["jeans"],"steps":[{"name":"Dip the yarn in indigo","process":"dye","text":"Warp yarns are gathered into long ropes and pulled through vats of indigo. Natural indigo comes from the indigo plant, though most denim today is dyed with synthetic indigo. Indigo dissolves in water only after a chemical change, and it turns blue again the instant air hits it. Several dips build the color up layer by layer.","inputs":["cotton-yarn","indigo-plant","water"]},{"name":"Air it blue","process":"dry","text":"Between dips, the ropes hang in the open air while the dye oxidizes. The dye clings to the outside of each yarn and does not reach the core, which leaves a pale center. This ring-dyed structure is why jeans fade.","inputs":[]},{"name":"Rewind onto beams","process":"assemble","text":"After dyeing, the ropes are separated and the yarns are re-beamed in parallel for weaving.","inputs":[]},{"name":"Weave a warp-faced twill","process":"weave","text":"The weft passes under two or more warp threads at a time, which makes a diagonal ribbing. Most denim today is woven on shuttleless looms, and some on old shuttle looms that produce a narrower bolt with a tidy edge called selvedge.","inputs":["cotton-yarn"]},{"name":"Preshrink the cloth","process":"press","text":"The woven cloth is sanforized, a mechanical treatment that shrinks it before it is cut into garments.","inputs":[]},{"name":"Roll into bolts","process":"package","text":"The finished cloth is inspected and rolled on tubes. Denim usually weighs 11 to 14 ounces per yard, but runs anywhere from 9 to 32.","inputs":[],"spec":"11 to 14 oz per yard"}],"facts":["The word denim comes from the French phrase serge de Nîmes, meaning serge from Nîmes.","Over 50 percent of denim is produced in Asia, most of it in China, India, Turkey, Pakistan and Bangladesh."],"where":[],"whereNote":null,"sources":[{"title":"Denim","url":"https://en.wikipedia.org/wiki/Denim"},{"title":"Weaving","url":"https://en.wikipedia.org/wiki/Weaving"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"dental-floss","name":"Dental floss","kind":"product","category":"body-health","title":"How dental floss is made","url":"https://assemblyline.org/make/dental-floss","stations":7,"upstream":35,"downstream":0,"depth":6,"dek":"Nylon replaced silk in floss during World War II because it resisted abrasion better and came in great lengths.","answer":"Nylon floss starts as polymer poured out in a ribbon and chopped to chips, which are remelted and pumped through spinnerets into filaments. The filaments gather into yarn and are twisted 2.5 to 3.5 turns an inch, which stops fraying. Baths add wax and flavor. It is wound on bobbins, usually placed in cases by hand and threaded around a metal cutter.","aka":["floss","interdental thread","waxed floss"],"inputs":["nylon","paraffin-wax","polypropylene","steel"],"uses":[],"grounds":["crude-oil","air","water","natural-gas","iron-ore","limestone","dolomite","manganese-ore","coal","quartz","timber","sulfur"],"upstreamSlugs":["nylon","paraffin-wax","polypropylene","steel","benzene","nitric-acid","ammonia","crude-oil","hydrogen","propylene","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","naphtha","toluene","air","water","natural-gas","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","sulfuric-acid","coal","quartz","charcoal","timber","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Chop the polymer","process":"cut","text":"Nylon salt polymerizes and pours out as a ribbon, which is cut into chips, flakes or pellets and blended.","inputs":["nylon"]},{"name":"Spin the filaments","process":"extrude","text":"Remelted chips are pumped through spinnerets. As the fine streams cool they solidify and regather into a yarn.","inputs":[]},{"name":"Twist the strand","process":"spin","text":"The ends of the filaments combine into one strand with 2.5 to 3.5 turns per inch. That twist adds strength and greatly cuts fraying and breaking. PTFE floss skips this as a single stretched filament.","inputs":[]},{"name":"Pull through coating baths","process":"coat","text":"The strand runs through emulsion baths of wax, flavor and other coatings at a steady speed. Patents add drying heat so the coating holds the floss in shape.","inputs":["paraffin-wax"]},{"name":"Wind the bobbins","process":"spin","text":"The coated strand is wound in cylindrical or roll-shaped bobbins. Cylindrical ones hold more yardage.","inputs":[]},{"name":"Mold the case","process":"mold","text":"The common case is an angled two-piece polypropylene shell with an insert to hold the spool. Some newer ones are one-piece clamshells with a window.","inputs":["polypropylene"]},{"name":"Assemble by hand","process":"assemble","text":"Workers usually cut bobbins apart and place them in the container, thread the floss around a metal cutting clip, and close the cover.","inputs":["steel"]}],"facts":["Levi Spear Parmly, a New Orleans dentist, recommended running waxed silk thread between the teeth in 1819.","Johnson & Johnson received the first patent for dental floss in 1898, using the same silk doctors used for stitches.","Nylon floss was developed during the war by the physician Charles C. Bass."],"where":[],"whereNote":null,"sources":[{"title":"Swicofil: Dental floss","url":"https://old.swicofil.com/dental_floss.html"},{"title":"US5526831A: Dental floss manufacturing process and product","url":"https://patents.google.com/patent/US5526831"},{"title":"Dental floss","url":"https://en.wikipedia.org/wiki/Dental_floss"},{"title":"Nylon","url":"https://en.wikipedia.org/wiki/Nylon"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"deodorant","name":"Deodorant","kind":"product","category":"body-health","title":"How deodorant is made","url":"https://assemblyline.org/make/deodorant","stations":7,"upstream":74,"downstream":0,"depth":10,"dek":"Deodorant does not stop sweat. Antiperspirant does, using aluminum salts that plug the sweat ducts.","answer":"Deodorant stick is a warm wax or gel base mixed with fragrance and an antibacterial agent, poured into a plastic tube and cooled until firm. Antiperspirants add aluminum salts that block sweat glands. Sprays are the same actives dissolved or suspended in a liquid and sealed in a can with a propellant.","aka":["antiperspirant","roll-on","underarm deodorant"],"inputs":["aluminum","hydrochloric-acid","paraffin-wax","vegetable-oil","silicone","perfume","polypropylene","ethanol","water","aluminum-can","natural-gas","cardboard-box"],"uses":[],"grounds":["water","natural-gas","crude-oil","coal","soybeans","rapeseed","clay","silica-sand","oranges","vanilla-pods","corn","sugarcane","bauxite","rock-salt","quartz","timber","limestone","sulfur","air","trona","sugar-beet","titanium-ore","iron-ore"],"upstreamSlugs":["aluminum","hydrochloric-acid","paraffin-wax","vegetable-oil","silicone","perfume","polypropylene","ethanol","water","aluminum-can","natural-gas","cardboard-box","crude-oil","coal","petroleum-coke","alumina","chlorine","hydrogen","soybeans","rapeseed","hexane","clay","silicon","methanol","silica-sand","oranges","vanilla-pods","glass-bottle","propylene","corn","sugarcane","yeast","ethylene","ink","epoxy","cardboard","adhesive","bauxite","caustic-soda","lime","rock-salt","sulfuric-acid","quartz","coke","charcoal","timber","soda-ash","limestone","polyethylene","naphtha","molasses","phenolic-resin","carbon-black","titanium-dioxide","pigment","phenol","acetone","wood-pulp","acrylic","polyurethane","sulfur","air","ammonia","carbon-dioxide","trona","sugar-beet","formaldehyde","titanium-ore","oxygen","iron-ore","benzene","hydrogen-peroxide","nitric-acid","toluene"],"downstreamSlugs":[],"steps":[{"name":"Make the aluminum salt","process":"react","text":"Aluminum is reacted with hydrochloric acid to form aluminum chloride, which is then partly converted to related salts that irritate skin less. These salts are what block the sweat ducts.","inputs":["aluminum","hydrochloric-acid"]},{"name":"Melt the stick base","process":"melt","text":"Waxes and fatty alcohols are heated together in a jacketed tank until they melt into a clear oil. This is the base that holds everything else.","inputs":["paraffin-wax","vegetable-oil"]},{"name":"Stir in the actives","process":"mix","text":"Powdered aluminum salt, a silicone oil for slip and a fragrance are stirred in while the base is still liquid. Bacteria-killing agents go in too.","inputs":["silicone","perfume"]},{"name":"Pour into tubes","process":"cast","text":"The warm mixture is poured into empty plastic tubes and cooled. The base sets in a block, and the dial at the bottom pushes the stick up.","inputs":["polypropylene"]},{"name":"Dissolve for sprays","process":"mix","text":"Spray versions combine the actives with ethanol or a carrier oil in a mixing tank. This liquid concentrate is filtered so it will not clog the nozzle.","inputs":["ethanol","water"]},{"name":"Charge the aerosol cans","process":"fill","text":"Cans receive the concentrate first, a valve is crimped on, and a liquefied hydrocarbon propellant is forced in through the valve. A water bath later checks for leaks.","inputs":["aluminum-can","natural-gas"]},{"name":"Cap and box","process":"package","text":"Caps are pressed on, batch codes are printed and the finished sticks and cans are packed into cartons.","inputs":["cardboard-box"]}],"facts":["The first modern commercial deodorant, Mum, appeared in 1888.","The modern antiperspirant formula was patented by Jules Montenier on January 28, 1941.","In 1977 the US Food and Drug Administration banned the aluminum zirconium active used in aerosols over inhalation concerns."],"where":[],"whereNote":null,"sources":[{"title":"Deodorant","url":"https://en.wikipedia.org/wiki/Deodorant"},{"title":"Perfume","url":"https://en.wikipedia.org/wiki/Perfume"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"globe","name":"Desk globe","kind":"product","category":"play","title":"How desk globes are made","url":"https://assemblyline.org/make/globe","stations":6,"upstream":53,"downstream":0,"depth":8,"dek":"A flat map has to be printed warped and then stretched back into shape, or it won't fit on a ball.","answer":"Most desk globes are vacuum-formed. A warped map is printed on flat PVC or vinyl, heated and sucked into a half-sphere, then trimmed and given a rigid shell, either bonded on or injection-molded behind it. Northern and southern halves are made separately and glued or snapped together. Some makers press cardboard hemispheres instead, and a few apply paper strips by hand.","aka":["world globe","terrestrial globe","earth globe"],"inputs":["pvc","ink","abs-plastic","acrylic","adhesive","plastic"],"uses":[],"grounds":["water","air","natural-gas","rock-salt","iron-ore","sulfur","soybeans","rapeseed","clay","crude-oil","titanium-ore","corn","sugarcane","coal","sugar-beet"],"upstreamSlugs":["pvc","ink","abs-plastic","acrylic","adhesive","plastic","ethylene","chlorine","water","pigment","plasticizer","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","ethanol","naphtha","propylene","ammonia","air","benzene","styrene","sulfuric-acid","methanol","polyethylene","epoxy","polyurethane","paraffin-wax","natural-gas","rock-salt","iron-ore","sulfur","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","titanium-ore","coke","oxygen","corn","sugarcane","yeast","hydrogen","toluene","acetone","caustic-soda","nitric-acid","coal","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Print the warped map","process":"print","text":"Each hemisphere's map is printed in distorted form on a flat, pliable PVC or vinyl sheet. Stretching over a dome will pull it back into shape, though the sheet can also stretch and shrink along its original extrusion direction.","inputs":["pvc","ink"]},{"name":"Vacuum-form the dome","process":"mold","text":"The sheet is heated in a vacuum former and drawn into a concave mold. The top of the dome tends to thin. One Chinese patent lays a small oval heat shield over the center so the sheet stays more even.","inputs":[]},{"name":"Trim the hemisphere","process":"cut","text":"Excess sheet is cut away. A second patent leaves a narrow rim around the dome, which the injection mold will grip.","inputs":[]},{"name":"Back it with a shell","process":"mold","text":"In one patented route the map film goes into an injection mold and ABS plastic shoots in behind it, faster than the hot film can shrink or wrinkle. Lit globes use a bonded inner shell of clear or white acrylic, so a lamp inside can shine through.","inputs":["abs-plastic","acrylic"]},{"name":"Join the hemispheres","process":"assemble","text":"Glue or snap fittings close the northern and southern halves into a sphere. On pressed-board globes, equator tape hides the seam.","inputs":["adhesive"]},{"name":"Mount on its stand","process":"assemble","text":"The sphere is tilted on an axis and fitted to its base. Globes lean 23.5 degrees to match Earth's axis.","inputs":["plastic"]}],"facts":["Martin Behaim's Erdapfel of 1492 is the oldest terrestrial globe still in existence.","A one-meter circumference, common on many globes, puts the model at a scale of 1:40 million.","Pressed-cardboard globes can show raised mountain ranges, but can have trouble lining up the text."],"where":[],"whereNote":null,"sources":[{"title":"How Globes Are Made: Production, Ultimate Globes","url":"https://ultimateglobes.com/blogs/learn-about-how-globes-are-made/how-globes-are-made-production"},{"title":"CN104175540A, Vacuum forming process of plastic globe drawing","url":"https://patents.google.com/patent/CN104175540A/en"},{"title":"CN104175464A, Injection moulding process of small plastic globe","url":"https://patents.google.com/patent/CN104175464A/en"},{"title":"US4300887A, Method of manufacture of raised relief illuminated globe","url":"https://patents.google.com/patent/US4300887A/en"},{"title":"Globe","url":"https://en.wikipedia.org/wiki/Globe"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"dice","name":"Dice","kind":"product","category":"play","title":"How dice are made","url":"https://assemblyline.org/make/dice","stations":7,"upstream":70,"downstream":0,"depth":10,"dek":"Casino dice have their dots drilled out and refilled with paint of exactly the same density as the plastic.","answer":"Mass-market dice are injection molded in a two-piece steel mold. The sprue is cut off, the dice are coated in paint and a tumbler rubs it away everywhere except the indented numbers, rounding the corners too. Casino dice skip all that: they are machined from plastic blocks, drilled at each pip and refilled with material of the same density, so every face weighs the same.","aka":["die","gaming dice","craps dice"],"inputs":["plastic","paint","cellulose-acetate"],"uses":[],"grounds":["natural-gas","water","crude-oil","titanium-ore","iron-ore","sulfur","timber","air","rock-salt","coal","limestone","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","dolomite","manganese-ore","quartz","sugar-beet"],"upstreamSlugs":["plastic","paint","cellulose-acetate","naphtha","natural-gas","ethylene","propylene","water","titanium-dioxide","pigment","acrylic","tin-can","wood-pulp","acetic-anhydride","acetone","plasticizer","crude-oil","hydrogen","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","carbon-black","sulfur","ammonia","methanol","tinplate","lacquer","ink","timber","caustic-soda","lime","hydrogen-peroxide","carbon-monoxide","benzene","air","rock-salt","coal","steel","tin","ethanol","vegetable-oil","phenolic-resin","limestone","toluene","pig-iron","magnesium","steel-scrap","manganese","argon","tin-ore","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","dolomite","silicon","propane","manganese-ore","molasses","quartz","charcoal","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Inject the plastic","process":"mold","text":"Molten acrylic or resin is forced at high pressure into a steel mold, usually two pieces pressed together. It cools, and the mold opens to eject the dice.","inputs":["plastic"]},{"name":"Trim the sprue","process":"cut","text":"Each die leaves the mold with a small nub where plastic entered, and that nub is cut off.","inputs":[]},{"name":"Paint and tumble","process":"grind","text":"Dice are coated in paint and tumbled. The action strips paint from everything but the indented numbers, and rounds and smooths the corners.","inputs":["paint"]},{"name":"Machine casino blocks","process":"machine","text":"Casino dice start as blocks of cellulose acetate rather than molded plastic, machined to a tolerance of about 1/2000th of an inch.","inputs":["cellulose-acetate"]},{"name":"Drill the pips","process":"machine","text":"Holes are drilled at every pip, removing a precise amount of plastic from each face.","inputs":[]},{"name":"Fill the pips flush","process":"fill","text":"Colored material of the same density as the plastic goes back into the holes, so each face weighs exactly the same as the others.","inputs":["paint"]},{"name":"Check size and balance","process":"inspect","text":"Finished dice are checked for defects and measured for dimensions, and sets are tested for balance and fair rolls.","inputs":[]}],"facts":["Casinos print a hidden letter or number under the paint of one pip, visible only when looking into the die at the right angle.","Dice have been found that date back to before recorded history, and some historians trace them to knucklebones.","Casinos favor transparent cellulose acetate dice because tampering is easier to see than in opaque dice."],"where":[],"whereNote":null,"sources":[{"title":"GM Dice: How are dice made?","url":"https://www.gmdice.com/blogs/dnd/how-are-dice-made"},{"title":"Eastar: The production process of dice","url":"https://www.eastarboardgame.com/News_event_id_521.html"},{"title":"Dice","url":"https://en.wikipedia.org/wiki/Dice"},{"title":"Casino Dice Designed to Thwart Customer Cheating","url":"https://www.doresabanning.com/casino-dice-designed-to-thwart-customer-cheating/"},{"title":"Cellulose acetate","url":"https://en.wikipedia.org/wiki/Cellulose_acetate"},{"title":"Injection moulding","url":"https://en.wikipedia.org/wiki/Injection_moulding"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"toy-car","name":"Die-cast toy car","kind":"product","category":"play","title":"How die-cast toy cars are made","url":"https://assemblyline.org/make/toy-car","stations":8,"upstream":71,"downstream":0,"depth":10,"dek":"Even a vintage hand-lever machine at New Zealand's Fun Ho! could fire over 3000 shots of zinc alloy a day.","answer":"Zinc alloy is pumped under pressure into a water-cooled steel die, freezes almost instantly and drops out as a tiny car body. Ejector pins leave small round marks you can still find on the casting. Excess metal is trimmed, the body is polished and spray-painted, and plastic windows, interiors and wheels are fitted around it.","aka":["diecast car","Hot Wheels","Matchbox car","model car"],"inputs":["zinc","aluminum","magnesium","copper","paint","plastic","steel"],"uses":[],"grounds":["zinc-ore","air","crude-oil","coal","dolomite","copper-ore","water","natural-gas","sulfur","bauxite","quartz","timber","titanium-ore","iron-ore","limestone","manganese-ore","rock-salt","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["zinc","aluminum","magnesium","copper","paint","plastic","steel","zinc-ore","air","sulfuric-acid","crude-oil","coal","petroleum-coke","alumina","dolomite","silicon","copper-ore","water","oxygen","titanium-dioxide","pigment","acrylic","tin-can","naphtha","natural-gas","ethylene","propylene","pig-iron","steel-scrap","lime","manganese","argon","sulfur","bauxite","caustic-soda","quartz","coke","charcoal","timber","titanium-ore","chlorine","iron-ore","carbon-black","ammonia","methanol","tinplate","lacquer","ink","hydrogen","limestone","propane","manganese-ore","rock-salt","tin","ethanol","vegetable-oil","phenolic-resin","tin-ore","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","molasses","benzene","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Cut the steel die","process":"machine","text":"A special steel die is cut by CNC machining or spark erosion, with cavities shaped like the product. Separate tubes inside circulate cold water, which controls the die's temperature.","inputs":[]},{"name":"Melt the zinc alloy","process":"melt","text":"Zamak, sold in Britain as Mazac, is melted in a furnace. A slight drop in temperature is enough to freeze it. Its zinc is refined to 99.99 percent purity to avoid zinc pest, a decay caused by impurities.","inputs":["zinc","aluminum","magnesium","copper"]},{"name":"Pump it into the die","process":"cast","text":"The die halves close hydraulically, and molten alloy is pumped into the cavity under pressure. Older machines needed one lever to close the die and another to shoot.","inputs":[]},{"name":"Eject the casting","process":"cast","text":"Circulating water sets the metal almost at once. The die clicks open and ejector pins push the body down a chute, each leaving a small circle where it pressed.","inputs":[]},{"name":"Trim and polish","process":"grind","text":"Excess metal is trimmed off, and the body is sanded and polished until it is smooth and free of defects.","inputs":[]},{"name":"Spray the paint","process":"coat","text":"Base coats, colors and clear finishes go on by airbrush, followed by decals and other small details.","inputs":["paint"]},{"name":"Mold the plastic parts","process":"mold","text":"Windows and tires are usually thermoplastic or rubber rather than metal. They and the interior are made separately from the body.","inputs":["plastic"]},{"name":"Fit wheels and interior","process":"assemble","text":"Interior details, windows and wheels on axles are joined to the die-cast body. A final quality check follows.","inputs":["steel"]}],"facts":["Hot Wheels went on sale in 1968, to give Mattel a toy line for boys to go with Barbie.","Matchbox cars took their name from small boxes that resembled the ones matches came in.","One small factory in Inglewood, New Zealand, made over 8 million zinc Midget toys between 1965 and 1982."],"where":[],"whereNote":null,"sources":[{"title":"Zinc diecast Midgets, Fun Ho! Toys","url":"https://funhotoys.co.nz/Fun-Ho-History/Fun-Ho-Toys/Zinc-diecast-Midgets.aspx"},{"title":"Die-cast Model Car: Casting Process and Sizes, ProleanTech","url":"https://proleantech.com/die-cast-model-car/"},{"title":"Die-cast toy","url":"https://en.wikipedia.org/wiki/Die-cast_toy"},{"title":"Zamak","url":"https://en.wikipedia.org/wiki/Zamak"},{"title":"Hot Wheels","url":"https://en.wikipedia.org/wiki/Hot_Wheels"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"diesel","name":"Diesel fuel","kind":"product","category":"chemicals","title":"How diesel fuel is made","url":"https://assemblyline.org/make/diesel","stations":5,"upstream":11,"downstream":1,"depth":5,"dek":"Diesel is the middle slice of crude oil, boiled off between kerosene and the heavy stuff, then scrubbed of sulfur.","answer":"Diesel is the part of crude oil that vaporizes at medium temperatures. It is drawn from the side of a distillation tower, treated with hydrogen to strip out sulfur, and blended with heavier or lighter streams to meet a standard for cold flow and ignition. Some biodiesel or additives may be mixed in.","aka":["diesel oil","gas oil","ULSD","distillate"],"inputs":["crude-oil","hydrogen","biodiesel"],"uses":["locomotive"],"grounds":["crude-oil","natural-gas","water","soybeans","rapeseed","clay"],"upstreamSlugs":["crude-oil","hydrogen","biodiesel","natural-gas","water","vegetable-oil","methanol","soybeans","rapeseed","hexane","clay"],"downstreamSlugs":["locomotive"],"steps":[{"name":"Desalt and heat the crude","process":"wash","text":"Crude is washed to remove salt and then heated in a furnace until most of it turns to vapor. The hot mixture feeds the base of the tower.","inputs":["crude-oil"]},{"name":"Draw the middle cut","process":"refine","text":"In the distillation tower, diesel condenses between kerosene above it and heavier gas oil below it. At normal pressure it boils off between 200 and 350 °C, and its molecules have 9 to 25 carbon atoms.","inputs":[],"spec":"boils from 200 to 350 °C"},{"name":"Treat it with hydrogen","process":"react","text":"The cut meets hydrogen over a catalyst in a process called hydrodesulfurization. Sulfur is converted to a gas and removed, which produces ultra-low-sulfur diesel.","inputs":["hydrogen"]},{"name":"Blend to a standard","process":"mix","text":"Blenders adjust the mix of streams, and sometimes biodiesel, to meet limits on cetane number, density, flash point and sulfur. Winter diesel is blended differently from summer diesel so that it keeps flowing in the cold.","inputs":["biodiesel"]},{"name":"Add additives and dispatch","process":"fill","text":"Small doses of additives improve cold flow, lubricity and cleanliness. Tank trucks and pipelines take the finished fuel to depots.","inputs":[]}],"facts":["The diesel engine shown at the 1900 Paris Exposition ran on peanut oil instead of crude oil, with no modifications.","Diesel can also be made without petroleum, from sources such as biodiesel, biomass or natural gas."],"where":[],"whereNote":null,"sources":[{"title":"Diesel fuel","url":"https://en.wikipedia.org/wiki/Diesel_fuel"},{"title":"Hydrodesulfurization","url":"https://en.wikipedia.org/wiki/Hydrodesulfurization"},{"title":"Oil refinery","url":"https://en.wikipedia.org/wiki/Oil_refinery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"digital-camera","name":"Digital camera","kind":"product","category":"electronics","title":"How digital cameras are made","url":"https://assemblyline.org/make/digital-camera","stations":8,"upstream":111,"downstream":0,"depth":10,"dek":"The top plate of one Fujifilm camera has 180 parts, and people, not robots, fit them.","answer":"High-end digital cameras are still largely built by hand. At Fujifilm's Taiwa factory, five sections made elsewhere arrive for final assembly, including a sensor housing and a magnesium alloy body. Workers fit hundreds of tiny parts with tweezers, wrap the body in leather and test it. A unit that fails one test returns to the line.","aka":["digicam","mirrorless camera","DSLR"],"inputs":["magnesium","polycarbonate","camera-sensor","printed-circuit-board","microchip","memory-chip","lithium-ion-cell","lcd-screen","copper-wire","camera-lens","leather"],"uses":[],"grounds":["dolomite","silica-sand","cattle-hide","rock-salt","water","quartz","coal","timber","air","crude-oil","copper-ore","limestone","tin-ore","gold-ore","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","iron-ore","natural-gas","sulfur","chromite","trona","lead-ore","silver-ore","zinc-ore","bauxite","titanium-ore","corn","sugarcane","sugar-beet"],"upstreamSlugs":["magnesium","polycarbonate","camera-sensor","printed-circuit-board","microchip","memory-chip","lithium-ion-cell","lcd-screen","copper-wire","camera-lens","leather","dolomite","silicon","phenol","propylene","acetone","caustic-soda","chlorine","silicon-wafer","copper","glass","fiberglass","epoxy","photoresist","solder","oxygen","tin","aluminum","gold","nitrogen","lithium-carbonate","cobalt","nickel","manganese","synthetic-graphite","polyethylene","steel","indium-tin-oxide","pigment","led","acrylic","silica-sand","adhesive","cattle-hide","rock-salt","water","lime","chromium","quartz","coke","coal","charcoal","timber","benzene","air","naphtha","crude-oil","sulfuric-acid","polysilicon","argon","copper-ore","soda-ash","limestone","phenolic-resin","lead","silver","tin-ore","petroleum-coke","alumina","gold-ore","zinc","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","iron-ore","natural-gas","ethylene","pig-iron","steel-scrap","indium","titanium-dioxide","carbon-black","sulfur","gallium","ammonia","hydrogen","plastic","methanol","polyurethane","paraffin-wax","chromite","toluene","hydrochloric-acid","trichlorosilane","carbon-dioxide","trona","formaldehyde","lead-ore","silver-ore","zinc-ore","bauxite","propane","titanium-ore","nitric-acid","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Form the body","process":"cast","inputs":["magnesium","polycarbonate"],"text":"Higher-end bodies use magnesium alloy. Cheaper cameras mold a chassis from polycarbonate with glass fiber in it, held to tight tolerances because everything else bolts to this frame."},{"name":"Mount sensor in clean air","process":"assemble","inputs":["camera-sensor"],"text":"Sensors are usually fitted by trained technicians in a dust-free clean room, an expensive way to work. One patent seals the sensor in its own module so the rest of the camera can be built in an ordinary electronics plant."},{"name":"Build the electronics","process":"assemble","inputs":["printed-circuit-board","microchip","memory-chip","lithium-ion-cell"],"text":"Circuits for the camera's controls are built as subassemblies and arrive ready to install. At Fujifilm, the parts are grouped into five sections in factories around the world, then shipped to Taiwa. Memory chips and battery cells come from outside makers too."},{"name":"Assemble the top plate","process":"assemble","inputs":["lcd-screen"],"text":"On the GFX 100, this slim strip holds a small status screen and a drive-mode button. Workers put it together by hand, using tweezers and magnifiers for the smallest pieces.","spec":"180 parts"},{"name":"Fit mount and front","process":"assemble","inputs":["copper-wire"],"text":"People set the lens mount ring on the body, then add copper contact wires and the finished sensor housing with its stabilizer. Each part is placed, checked and checked again before the section moves on.","spec":"320 parts"},{"name":"Clean and stack lenses","process":"assemble","inputs":["camera-lens"],"text":"Lenses are hand-assembled in a clean room, where visitors wear full suits and leave camera straps outside to keep out stray fibers. Each piece of glass is cleaned several times before it goes in the tube."},{"name":"Wrap in leather","process":"laminate","inputs":["leather"],"text":"After the back panel goes on, the leather covering is stretched over the metal body. Trained staff may need up to 20 minutes, though workers on the floor were seen doing it in a few."},{"name":"Test every unit","process":"inspect","inputs":[],"text":"A camera that fails a single test goes back to be refitted. An adapter stays in the USB port throughout so repeated cable changes do not wear it, and random units are tested again on the packaging floor."}],"facts":["Fujifilm workers can wrap leather over a camera body in under two minutes, while visiting journalists took well over five.","Steven Sasson of Eastman Kodak made a self-contained electronic camera in 1975, using a monochrome Fairchild CCD sensor.","NASA's Jet Propulsion Laboratory developed the CMOS active-pixel sensor in 1993."],"where":[],"whereNote":null,"sources":[{"title":"How it's made: on the factory floor with the 102MP Fujifilm GFX 100","url":"https://www.techradar.com/news/how-its-made-on-the-factory-floor-with-the-monstrous-102mp-fujifilm-gfx-100"},{"title":"US9661235: Camera having a separate image capture module and a method of assembling the camera","url":"https://patents.google.com/patent/US9661235"},{"title":"Camera (How Products Are Made)","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/camera"},{"title":"Digital camera","url":"https://en.wikipedia.org/wiki/Digital_camera"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"thermometer","name":"Digital thermometer","kind":"product","category":"body-health","title":"How digital thermometers are made","url":"https://assemblyline.org/make/thermometer","stations":7,"upstream":79,"downstream":0,"depth":9,"dek":"Inside a digital thermometer is a bead of sintered metal oxide whose electrical resistance changes with heat.","answer":"A digital thermometer measures temperature with a thermistor, a small bead of pressed and fired metal oxide whose electrical resistance changes with heat. The bead is coated in epoxy or glass, wired to a small chip and a battery, and sealed in a plastic body with a stainless tip. Each unit is calibrated against a reference before sale.","aka":["electronic thermometer","fever thermometer","thermistor"],"inputs":["manganese","nickel","copper","epoxy","glass","microchip","printed-circuit-board","abs-plastic"],"uses":[],"grounds":["manganese-ore","iron-ore","natural-gas","nickel-ore","copper-ore","water","air","silica-sand","limestone","coal","sulfur","crude-oil","rock-salt","trona","quartz","tin-ore","gold-ore","corn","bauxite","zinc-ore","lead-ore","silver-ore","titanium-ore","timber","sugarcane","sugar-beet"],"upstreamSlugs":["manganese","nickel","copper","epoxy","glass","microchip","printed-circuit-board","abs-plastic","manganese-ore","iron-ore","coke","sulfuric-acid","natural-gas","nickel-ore","copper-ore","water","oxygen","air","phenol","propylene","acetone","chlorine","caustic-soda","silica-sand","soda-ash","limestone","silicon-wafer","photoresist","tin","aluminum","gold","fiberglass","solder","naphtha","ammonia","benzene","ethylene","styrene","pigment","coal","sulfur","crude-oil","rock-salt","carbon-dioxide","lime","trona","polysilicon","quartz","argon","phenolic-resin","tin-ore","petroleum-coke","alumina","gold-ore","zinc","lead","silver","hydrogen","toluene","titanium-dioxide","carbon-black","corn","yeast","silicon","hydrochloric-acid","trichlorosilane","nitrogen","formaldehyde","bauxite","zinc-ore","lead-ore","silver-ore","titanium-ore","molasses","charcoal","timber","methanol","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Press the oxide powder","process":"press","text":"Powders of metal oxides are mixed and pressed into a bead, disk or cylinder. The blend decides how strongly resistance shifts as temperature climbs.","inputs":["manganese","nickel"]},{"name":"Fire the bead","process":"fire","text":"A kiln sinters the pressed shapes so the grains fuse into a hard ceramic. Fine adjustments in the firing control the resistance.","inputs":[]},{"name":"Attach the leads","process":"weld","text":"Metal contacts are added and thin wires are attached to the bead. These carry the signal out of the probe.","inputs":["copper"]},{"name":"Encapsulate it","process":"coat","text":"The bead is sealed in epoxy or glass so moisture can't change its behavior. A metal tip or plastic cap then covers the sensor.","inputs":["epoxy","glass"]},{"name":"Wire up the electronics","process":"assemble","text":"The sensor connects to a small board with a chip that turns resistance into a temperature, then to a display and a small button cell.","inputs":["microchip","printed-circuit-board"]},{"name":"Mold the housing","process":"mold","text":"Plastic halves are injection molded, then snapped and sealed around the board, with a window for the display.","inputs":["abs-plastic"]},{"name":"Calibrate each unit","process":"inspect","text":"Thermometers are dipped in a bath held at known temperatures. Software stores the correction so every reading matches the reference.","inputs":[]}],"facts":["The first thermistor effect was reported by Michael Faraday in 1833, when he saw that the resistance of silver sulfide fell as it warmed.","Modern thermistors are typically pressed into a bead, disk or cylinder and then sealed in epoxy or glass."],"where":[],"whereNote":null,"sources":[{"title":"Thermometer","url":"https://en.wikipedia.org/wiki/Thermometer"},{"title":"Thermistor","url":"https://en.wikipedia.org/wiki/Thermistor"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"dinner-plate","name":"Dinner plate","kind":"product","category":"minerals","title":"How dinner plates are made","url":"https://assemblyline.org/make/dinner-plate","stations":8,"upstream":2,"downstream":0,"depth":1,"dek":"A freshly formed plate is about an inch wider than the one on your table, because the kiln shrinks it.","answer":"Dry clay is blunged with water for about two hours, pressed into filter cakes and extruded into pugs. A slice of pug spins against a plaster mold on a jigger machine, which forms the plate from above. It dries, is trimmed on a wheel, sprayed with glaze and wiped clean at the foot before it enters the kiln.","aka":["dish","china plate","porcelain plate","ceramic plate"],"inputs":["clay","water"],"uses":[],"grounds":["clay","water"],"upstreamSlugs":["clay","water"],"downstreamSlugs":[],"steps":[{"name":"Blunge the clay","process":"mix","text":"Dry clay, which arrives at one California factory in 600-pound bags, is stirred with water in a blunger about two hours. The result is a slurry whose consistency matters as much as a cake batter's.","inputs":["clay","water"]},{"name":"Press out the water","process":"press","text":"A hydraulic press squeezes water from the slurry and leaves waffle-like filter cakes of clay.","inputs":[]},{"name":"Extrude the pugs","process":"extrude","text":"A pug mill forces the cakes into dense tubes called pugs. At the forming station a cutter slices them into small round cakes.","inputs":[]},{"name":"Jigger the plate","process":"mold","text":"A clay cake lands on a spinning plaster mold, and a jigger machine forms it from the top down. Bowls go the other way, on a jolly. Some factories instead press a damp powder in a die.","inputs":[]},{"name":"Dry and trim","process":"dry","text":"Warm air turns the wet clay into stiff greenware. Spinning on a wheel, each plate has its edge scraped smooth. Broken pieces go back to the blunger, so nothing is wasted.","inputs":[]},{"name":"Spray and wipe","process":"coat","text":"A worker centers each plate and sprays a set amount of glaze in a set pattern. The foot is then wiped on a belt, because glaze touching a kiln shelf would fuse the plate to it.","inputs":[]},{"name":"Fire in the kiln","process":"fire","text":"Plates are placed where the kiln's hot and cool spots suit each glaze, and a fire tender adjusts the gas through an eight-hour run. Other makers fire twice, once for the body and once for the glaze.","inputs":[]},{"name":"Decorate and grade","process":"inspect","text":"Inspectors grade each plate first or second quality and polish the bottom. Lines that use decals apply them after the glaze and give the plate another firing.","inputs":[]}],"facts":["The diameter of the typical dinner plate is estimated to have grown by 65% since 1000 AD.","Pad printing, which transfers images with flexible silicone pads, was developed in the late 1940s."],"where":[],"whereNote":null,"sources":[{"title":"Heath Ceramics: Follow the plate","url":"https://www.heathceramics.com/blogs/heath-journal/follow-the-plate"},{"title":"Gibson Homewares: How is dinnerware made?","url":"https://gibsonhomewares.com/blogs/behind-the-process/how-is-dinnerware-made"},{"title":"Plate (dishware)","url":"https://en.wikipedia.org/wiki/Plate_(dishware)"},{"title":"Pottery","url":"https://en.wikipedia.org/wiki/Pottery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"dish-soap","name":"Dish soap","kind":"product","category":"body-health","title":"How dish soap is made","url":"https://assemblyline.org/make/dish-soap","stations":6,"upstream":33,"downstream":0,"depth":7,"dek":"Dish soap is not soap at all, because real soap would leave a film in hard water.","answer":"Dish soap is a cold or gently warmed blend, not a reaction. Plants weigh and test the raw materials, then charge large tanks with purified water and primary surfactants. Hydrotropes keep the concentrate dissolved, and thickeners, color and fragrance go in late. After tests for viscosity, clarity and cleaning power, it goes to automatic fillers, cappers and labelers.","aka":["dishwashing liquid","washing-up liquid","dish detergent"],"inputs":["water","table-salt","perfume","plastic-bottle"],"uses":[],"grounds":["water","rock-salt","seawater","oranges","vanilla-pods","corn","sugarcane","silica-sand","limestone","natural-gas","trona","sugar-beet","crude-oil","air"],"upstreamSlugs":["water","table-salt","perfume","plastic-bottle","rock-salt","seawater","oranges","vanilla-pods","ethanol","glass-bottle","pet-plastic","corn","sugarcane","yeast","ethylene","silica-sand","soda-ash","limestone","polyethylene","p-xylene","ethylene-glycol","molasses","naphtha","natural-gas","ammonia","carbon-dioxide","lime","trona","oxygen","sugar-beet","crude-oil","hydrogen","air"],"downstreamSlugs":[],"steps":[{"name":"Weigh and test","process":"inspect","text":"Cleaning chemicals, foaming agents and additives are weighed and tested so the ratio matches the formula.","inputs":[]},{"name":"Charge the tank","process":"mix","text":"Purified water and primary surfactants go into large mixing tanks with automatic stirrers, with temperature and time held under control until everything has dissolved.","inputs":["water"]},{"name":"Add foam boosters","process":"mix","text":"Milder secondary surfactants bring extra foam, and hydrotropes such as sodium xylene sulfonate stop the concentrate from separating.","inputs":[]},{"name":"Thicken, scent and color","process":"mix","text":"Thickeners, colorants and fragrances come in late in the mixing cycle. Salt can help build thickness.","inputs":["table-salt","perfume"]},{"name":"Test the batch","process":"inspect","text":"Samples are checked for viscosity, clarity and cleaning performance before any bottle is filled.","inputs":[]},{"name":"Fill, cap and label","process":"fill","text":"An automatic filler doses an exact volume in each bottle. Cappers seal them against leaks, labelers finish them, and they are inspected and boxed.","inputs":["plastic-bottle"]}],"facts":["Procter & Gamble introduced Joy in 1949, as one of the first nationally marketed liquid dish soaps in the United States.","Dawn, launched in 1973, is also used by wildlife rescuers to clean oil off birds and marine mammals.","The antibacterial agent triclosan, once added to some dish liquids, has been banned in the United States, the European Union and elsewhere."],"where":[],"whereNote":null,"sources":[{"title":"Biology Insights: How is dish soap made?","url":"https://biologyinsights.com/how-is-dish-soap-made-the-science-process-explained/"},{"title":"Intech Vietnam: Dishwashing liquid production line","url":"https://intechvietnam.com/news/tech-news/dishwashing-liquid-production-line-what-you-need-to-know-1473/"},{"title":"Dishwashing liquid","url":"https://en.wikipedia.org/wiki/Dishwashing_liquid"},{"title":"Surfactant","url":"https://en.wikipedia.org/wiki/Surfactant"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"dishwasher","name":"Dishwasher","kind":"product","category":"machines","title":"How dishwashers are made","url":"https://assemblyline.org/make/dishwasher","stations":11,"upstream":94,"downstream":0,"depth":10,"dek":"The tub comes out of a steel tool as one hot piece of plastic, then cools until workers can handle it.","answer":"The tub is usually stainless steel sheet, while cheaper models injection mold it in one piece from reinforced polypropylene. Coils of steel become doors and cabinets. Wire is welded into racks and baked with a PVC or nylon skin. On the line, workers bolt motors to a frame, fasten the tub over them, add spray arms, racks and door, then wrap the machine in bagged insulation.","aka":["dish washer","dishwashing machine"],"inputs":["polypropylene","stainless-steel","sheet-steel","steel","steel-wire","pvc","nylon","electric-motor","insulation","cardboard-box"],"uses":[],"grounds":["water","silica-sand","crude-oil","chromite","limestone","air","nickel-ore","zinc-ore","iron-ore","dolomite","manganese-ore","natural-gas","rock-salt","sulfur","coal","trona","quartz","timber","titanium-ore","copper-ore","soybeans","rapeseed","clay","corn","sugarcane","bauxite","sugar-beet"],"upstreamSlugs":["polypropylene","stainless-steel","sheet-steel","steel","steel-wire","pvc","nylon","electric-motor","insulation","cardboard-box","propylene","steel-scrap","chromium","nickel","oxygen","argon","zinc","pig-iron","magnesium","lime","manganese","ethylene","chlorine","water","pigment","plasticizer","benzene","nitric-acid","ammonia","copper-wire","epoxy","ball-bearing","silica-sand","adhesive","cardboard","ink","naphtha","crude-oil","propane","chromite","coke","soda-ash","limestone","air","aluminum","nickel-ore","sulfuric-acid","zinc-ore","iron-ore","dolomite","silicon","manganese-ore","natural-gas","rock-salt","titanium-dioxide","carbon-black","sulfur","hydrogen","toluene","copper","phenol","acetone","caustic-soda","polyethylene","acrylic","polyurethane","paraffin-wax","wood-pulp","vegetable-oil","phenolic-resin","ethanol","coal","carbon-dioxide","trona","petroleum-coke","alumina","quartz","charcoal","timber","titanium-ore","copper-ore","methanol","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","formaldehyde","corn","sugarcane","yeast","bauxite","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the tub","process":"mold","inputs":["polypropylene"],"text":"Molten polypropylene is forced under pressure into the space between two halves of a steel tool, filling every crevice. The hot tub is carried to a cooling area until workers can handle it. One patent lines the tub by first spraying stainless steel onto the mold core."},{"name":"Mold the small parts","process":"mold","inputs":["polypropylene"],"text":"Cutlery baskets, detergent cups, the wash tower and spray arms are molded the same way. They wait in bins, one kind of part to a bin, until the line calls for them."},{"name":"Stamp doors and cabinets","process":"stamp","inputs":["stainless-steel","sheet-steel"],"text":"Prefinished coils of steel are cut and stamped into tubs, doors and, for stand-alone models, wrap-around cabinets."},{"name":"Shear the frame bars","process":"cut","inputs":["steel"],"text":"Flat steel bars are sheared to length, ready to be assembled into the frame that carries everything else."},{"name":"Weld the racks","process":"weld","inputs":["steel-wire"],"text":"Coiled wire is trimmed, deburred and shaped. One tool welds all the pieces of the rack's perimeter at once, and another welds on the tines that hold the dishes."},{"name":"Bake on the coating","process":"coat","inputs":["pvc","nylon"],"text":"After cleaning, each rack gets a fine PVC or nylon powder that is baked on and cured, so the tines will not scratch plates."},{"name":"Mount motors on frame","process":"assemble","inputs":["electric-motor"],"text":"Workers build the frame first and attach one or two motors, which arrive from subcontractors as finished assemblies, to special mounts."},{"name":"Fit tub and interior","process":"assemble","inputs":[],"text":"The tub is fastened into the frame over the motors. First comes the filter, then the wash tower and arms, the rack rollers, the racks and the cutlery basket."},{"name":"Hang the door","process":"assemble","inputs":[],"text":"The door gets its detergent dispenser, rinse-agent cups and controls and is attached to the front. Electrical connections and the clean and dirty water lines are then finished."},{"name":"Wrap in insulation","process":"assemble","inputs":["insulation"],"text":"Fibers sealed in a foil-like bag are wrapped around the machine and packed into the toe space. They cut noise and keep heat from warping nearby counters."},{"name":"Inspect and carton","process":"package","inputs":["cardboard-box"],"text":"Quality engineers inspect finished machines and test selected units. Foam bumpers go on the edges, then a carton with the instructions on top."}],"facts":["Dishwasher rack tines are baked in a skin of PVC or nylon powder so they will not scratch your plates.","A rinse aid cuts the surface tension of the water, so the last drops run off and leave fewer spots.","Some dishwashers use two motors, one for the water pump and one for draining, which needs less insulation for quiet running."],"where":[],"whereNote":null,"sources":[{"title":"Dishwasher (How Products Are Made)","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/dishwasher"},{"title":"US6716383: Method of forming an appliance washing tub","url":"https://patents.google.com/patent/US6716383"},{"title":"Dishwasher","url":"https://en.wikipedia.org/wiki/Dishwasher"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"diaper","name":"Disposable diaper","kind":"product","category":"textiles","title":"How disposable diapers are made","url":"https://assemblyline.org/make/diaper","stations":6,"upstream":36,"downstream":0,"depth":8,"dek":"A disposable diaper is a stack of thin layers built around a core that soaks up urine and locks it in.","answer":"A disposable diaper is assembled in layers on a fast moving line. A core of air-laid paper fluff mixed with superabsorbent polymer is laid between a soft nonwoven layer on the skin side and a breathable polyethylene film on the outside. Elastics and tapes are added, and the web is cut and folded.","aka":["nappy","disposable nappy","baby diaper"],"inputs":["wood-pulp","superabsorbent-polymer","polypropylene","polyethylene","adhesive"],"uses":[],"grounds":["timber","water","rock-salt","limestone","air","crude-oil","natural-gas","sulfur","coal"],"upstreamSlugs":["wood-pulp","superabsorbent-polymer","polypropylene","polyethylene","adhesive","timber","caustic-soda","water","lime","oxygen","hydrogen-peroxide","acrylic-acid","propylene","ethylene","acrylic","epoxy","polyurethane","paraffin-wax","rock-salt","limestone","air","hydrogen","naphtha","crude-oil","natural-gas","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","sulfur","benzene","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Fluff the core","process":"mix","text":"Wood pulp is shredded into fluff and blended with superabsorbent polymer granules, then laid down as an absorbent pad. The superabsorbent grabs the liquid and keeps it from coming back out.","inputs":["wood-pulp","superabsorbent-polymer"]},{"name":"Cover the skin side","process":"laminate","text":"A layer of soft nonwoven fabric is laid next to the skin, with a distribution layer beneath that spreads wetness to the core. The nonwoven can be made of polypropylene.","inputs":["polypropylene"]},{"name":"Seal the outer shell","process":"laminate","text":"The outside is a breathable polyethylene film, or a film and nonwoven composite. It keeps wetness and soil from passing through.","inputs":["polyethylene","adhesive"]},{"name":"Add elastics and tapes","process":"assemble","text":"Elasticized fabric is attached around the legs and waist. Adhesive or mechanical fastening tapes go on the back, and some can be refastened.","inputs":["adhesive"]},{"name":"Cut and fold","process":"cut","text":"The continuous web is cut into single diapers, which are folded into compact shape.","inputs":[]},{"name":"Count and bag","process":"package","text":"Diapers are counted by machine into stacks and sealed in plastic bags or boxes.","inputs":[]}],"facts":["In 1946 Marion Donovan used a shower curtain from her bathroom to create the Boater, a diaper cover made from army surplus nylon parachute cloth.","Procter & Gamble began researching disposable diapers in 1956.","More than US$9 billion is spent on disposable diapers in North America each year."],"where":[],"whereNote":null,"sources":[{"title":"Diaper","url":"https://en.wikipedia.org/wiki/Diaper"},{"title":"Nonwoven fabric","url":"https://en.wikipedia.org/wiki/Nonwoven_fabric"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"dolomite","name":"Dolomite","kind":"raw","category":"ground","title":"How dolomite rock is quarried","url":"https://assemblyline.org/make/dolomite","stations":3,"upstream":0,"downstream":166,"depth":0,"dek":"Dolomite rock is a limestone that magnesium moved into, and it barely fizzes in acid.","answer":"Dolomite is a sedimentary rock made mostly of calcium magnesium carbonate. Most of it began as limestone that magnesium-rich water later changed, so quarries find it next to limestone. Crews quarry the bed, crush it and screen it. Magnesium smelters are among the buyers.","aka":["dolostone","dolomitic rock","magnesian limestone"],"inputs":[],"uses":["window-glass","magnesium"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["window-glass","magnesium","mirror","skyscraper","windshield","double-glazed-window","steel","titanium","water-heater","toy-car","digital-camera","car","electric-car","aluminum-window-frame","toothbrush","lithium-ion-cell","ev-battery","aa-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","inkjet-printer","electric-toothbrush","pacemaker","hip-implant","jet-engine","prosthetic-leg","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","e-reader","refrigerator","microwave-oven","washing-machine","blender","air-conditioner","treadmill","game-console","graphics-card","phone-charger","safety-pin","airbag","ceiling-fan","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","concrete","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sailboat","action-figure","power-outlet","champagne","electric-kettle","pencil","golf-ball","wallpaper","wooden-chair","water-bottle","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","snow-globe","neon-sign","toffee"],"steps":[{"name":"Find a dolomitized bed","process":"mine","text":"Most dolomite formed when magnesium replaced calcium in limestone or lime mud. Geologists check a field sample with a drop of dilute acid, because dolomite fizzes only weakly while limestone fizzes hard.","inputs":[]},{"name":"Blast and quarry the rock","process":"mine","text":"The rock is soft, rated 4 or less on the Mohs scale, and resists erosion. Crews take it from open quarries.","inputs":[]},{"name":"Crush and size the stone","process":"crush","text":"Quarried rock is crushed and screened into sizes for each customer. One of its destinations is a magnesium smelter.","inputs":[]}],"facts":["Dolomite makes up about 80 percent of the carbonate rock that holds petroleum.","Dolomite is named after Déodat Gratet de Dolomieu, who described the rock in 1791 after noticing it in the buildings of old Rome."],"where":[],"whereNote":null,"sources":[{"title":"Dolomite (rock)","url":"https://en.wikipedia.org/wiki/Dolomite_(rock)"},{"title":"Dolomite (mineral)","url":"https://en.wikipedia.org/wiki/Dolomite_(mineral)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"donut","name":"Donut","kind":"product","category":"food","title":"How donuts are made","url":"https://assemblyline.org/make/donut","stations":6,"upstream":70,"downstream":0,"depth":10,"dek":"A donut floats in hot oil, browns one side, and gets flipped to brown the other.","answer":"On an automated line, dough from flour, yeast, sugar and fat is poured into a hopper and pushed through an extruder that forms rings with the hole already in place. The rings ride through a warm, humid proof box, float through oil at around 355 to 360 °F, flip once, and pass under a curtain of glaze.","aka":["doughnut","ring doughnut","jelly doughnut"],"inputs":["flour","sugar","yeast","eggs","water","vegetable-oil","sprinkles","cardboard-box"],"uses":[],"grounds":["eggs","water","wheat","sugarcane","sugar-beet","soybeans","rapeseed","clay","air","limestone","crude-oil","corn","cocoa-beans","iron-ore","sulfur","natural-gas","titanium-ore","timber","rock-salt","coal"],"upstreamSlugs":["flour","sugar","yeast","eggs","water","vegetable-oil","sprinkles","cardboard-box","wheat","vitamin-c","sugarcane","sugar-beet","lime","molasses","soybeans","rapeseed","hexane","clay","corn-starch","cocoa-powder","corn-syrup","pigment","cardboard","ink","adhesive","hydrogen","air","plastic-bottle","limestone","crude-oil","corn","cocoa-beans","iron-ore","titanium-dioxide","carbon-black","sulfur","wood-pulp","phenolic-resin","ethanol","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","natural-gas","pet-plastic","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","timber","caustic-soda","hydrogen-peroxide","phenol","formaldehyde","ethylene","propylene","ammonia","methanol","acetone","nitric-acid","p-xylene","ethylene-glycol","rock-salt","coal","benzene","naphtha","carbon-dioxide","toluene"],"downstreamSlugs":[],"steps":[{"name":"Weigh and mix","process":"knead","text":"Ingredients are weighed on digital scales and carried by automated machines into the mixer. Many shops start from a prepared mix and add water and yeast at this point.","inputs":["flour","sugar","yeast","eggs","water","vegetable-oil"]},{"name":"Extrude the rings","process":"extrude","text":"Dough drops into a hopper, and an extruder pushes it out in rings. The machine forms the hole as it shapes the ring, so nothing is punched out. Pressurized air keeps the thickness even.","inputs":[]},{"name":"Rise in the proof box","process":"ferment","text":"Trays climb up and down a zig-zag conveyor in a tall case full of heat and humidity, around 51 °C for up to 30 minutes in one description. Yeast turns sugar into gas and the rings puff up. Cake donuts skip this and use baking powder.","inputs":[]},{"name":"Float through hot oil","process":"cook","text":"Rings float on vegetable oil at about 355 to 360 °F while a conveyor carries them along. One side fries first, then a flipper turns them over for the other, roughly 45 seconds a side.","inputs":["vegetable-oil"],"spec":"355-360 °F"},{"name":"Pass under the waterfall","process":"coat","text":"Still on the conveyor, each rack runs through a falling curtain of glaze. A pump lifts the glaze from a reservoir to the top of the waterfall, and whatever misses returns to fall again.","inputs":["sugar"]},{"name":"Cool, top and box","process":"chill","text":"The line goes through a cooling stage, sometimes a refrigerated tunnel. Sprinkles and other toppings go on before the donuts are boxed.","inputs":["sprinkles","cardboard-box"]}],"facts":["Hanson Gregory claimed to have invented the ring-shaped doughnut in 1847 aboard a lime-trading ship, punching the hole with a tin pepper box.","The first known printed use of the spelling donut was in a book published in 1900.","Cato the Elder recorded a recipe for a deep-fried dough ball made with cheese, honey and poppy seeds."],"where":[],"whereNote":null,"sources":[{"title":"Ohio State University: Krispy Kreme manufacturing process","url":"https://u.osu.edu/krispykremecommoditychain/manufacturing-process"},{"title":"University of British Columbia FNH 200: Donuts","url":"https://wiki.ubc.ca/Course:FNH200/Assignments/2024/Donuts"},{"title":"US3882768A: Automatic donut making system","url":"https://patents.google.com/patent/US3882768A/en"},{"title":"Doughnut","url":"https://en.wikipedia.org/wiki/Doughnut"},{"title":"Bread","url":"https://en.wikipedia.org/wiki/Bread"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hinge","name":"Door hinge","kind":"product","category":"hardware","title":"How door hinges are made","url":"https://assemblyline.org/make/hinge","stations":7,"upstream":42,"downstream":0,"depth":6,"dek":"A top-grade butt hinge must pass 2.5 million open-and-close cycles to earn its rating.","answer":"Most butt hinges begin in a stamping press, where sheet metal feeds through dies that cut the leaves, punch the screw holes and countersinks, and shape the edges. Machining can tighten the pin fit. Each leaf's edge is rolled into knuckles, a pin joins the pair, and a finish such as plating goes on before samples face cycle testing.","aka":["butt hinge","door hinge"],"inputs":["sheet-steel","brass","steel-wire"],"uses":[],"grounds":["zinc-ore","air","copper-ore","water","lead-ore","tin-ore","crude-oil","coal","iron-ore","limestone","dolomite","manganese-ore","natural-gas","sulfur","bauxite","quartz","timber","rock-salt"],"upstreamSlugs":["sheet-steel","brass","steel-wire","steel","zinc","copper","lead","tin","aluminum","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","copper-ore","water","lead-ore","coke","tin-ore","crude-oil","coal","petroleum-coke","alumina","iron-ore","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","sulfur","bauxite","caustic-soda","quartz","charcoal","timber","rock-salt"],"downstreamSlugs":[],"steps":[{"name":"Blank the sheet","process":"stamp","text":"Sheet or profile in stainless steel, brass or aluminum alloy is cut or blanked into flat pieces. Stamping comes first because it suits high volumes.","inputs":["sheet-steel","brass"]},{"name":"Punch the screw holes","process":"stamp","text":"Dies form the leaf shape, screw holes, countersinks and edges. A stable die keeps batches matching, which matters when every hinge on a door has to line up.","inputs":[]},{"name":"Machine the tight spots","process":"machine","text":"Where stamping is not accurate enough, cutters finish holes and slots and true up the surfaces that meet the pin or bearings.","inputs":[]},{"name":"Roll the knuckles","process":"press","text":"The edge of each leaf is rolled or formed into knuckles that interlock with those on the opposite leaf.","inputs":[]},{"name":"Join with the pin","process":"assemble","text":"The knuckles are matched up with a pin, and some models add bearings or bushings. This fit sets how the hinge feels and sounds, how fast it wears, and how well it resists sag.","inputs":["steel-wire"]},{"name":"Finish the surface","process":"coat","text":"The assembled body is polished, brushed, plated, passivated or powder coated. For hinges facing humidity or coastal air, this layer is what holds off corrosion.","inputs":[]},{"name":"Cycle-test samples","process":"inspect","text":"The ANSI and BHMA A156.1 standard covers cycle, wear, friction, strength, finish and dimensional checks on hinges.","inputs":[],"spec":"2.5 million cycles for Grade 1"}],"facts":["Hinges of stone, marble, wood and bronze survive from antiquity, some going back to ancient Egypt.","One patent makes a self-closing hinge's pin from the leaf itself, curling the metal past 425° so no separate pin has to be fitted.","Ancient Egyptian doors swung on pivots that stuck out from the door's edge, either carved from the door or added as dowels."],"where":[],"whereNote":null,"sources":[{"title":"Hinge","url":"https://en.wikipedia.org/wiki/Hinge"},{"title":"What Manufacturing Processes Are Used For Door Hinges?, YAKO","url":"https://www.yako-hw.com/news/357/"},{"title":"US4379360A: Method of making a hinge with an integral pintle","url":"https://patents.google.com/patent/US4379360A/en"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"double-glazed-window","name":"Double-glazed window","kind":"product","category":"minerals","title":"How double-glazed windows are made","url":"https://assemblyline.org/make/double-glazed-window","stations":6,"upstream":55,"downstream":1,"depth":8,"dek":"The insulation in a double-glazed window is the gap between the panes, often filled with argon.","answer":"Two panes of glass are cut, washed and separated by a hollow spacer bar filled with moisture-absorbing desiccant. Sealant bonds the panes to the spacer to make a closed gap. The gap is filled with air or argon, and the edge is sealed again. Some panes carry an invisible low-emissivity coating.","aka":["insulated glass unit","IGU","double glazing","double-pane window"],"inputs":["window-glass","aluminum","adhesive","argon","silicone"],"uses":["aluminum-window-frame"],"grounds":["silica-sand","limestone","dolomite","crude-oil","coal","water","air","rock-salt","trona","tin-ore","natural-gas","bauxite","quartz","timber","corn","sulfur","sugarcane","sugar-beet"],"upstreamSlugs":["window-glass","aluminum","adhesive","argon","silicone","silica-sand","soda-ash","limestone","dolomite","tin","nitrogen","hydrogen","crude-oil","coal","petroleum-coke","alumina","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","air","silicon","methanol","hydrochloric-acid","rock-salt","ammonia","carbon-dioxide","lime","trona","tin-ore","coke","natural-gas","bauxite","caustic-soda","ethylene","propylene","sulfuric-acid","phenol","acetone","chlorine","nitric-acid","quartz","charcoal","timber","corn","yeast","naphtha","sulfur","benzene","molasses","toluene","sugarcane","sugar-beet"],"downstreamSlugs":["aluminum-window-frame"],"steps":[{"name":"Cut the panes","process":"cut","text":"Sheets of glass are scored and snapped to size. Panes usually range from 3 to 10 mm thick.","inputs":["window-glass"]},{"name":"Wash and dry","process":"wash","text":"A washing line scrubs the glass in clean water and dries it, because any dust left inside the unit stays there for good.","inputs":[]},{"name":"Bend the spacer frame","process":"assemble","text":"A hollow spacer bar is bent into a frame and filled with desiccant. The desiccant absorbs the moisture trapped inside during manufacture, so the glass won't fog.","inputs":["aluminum"]},{"name":"Seal pane to spacer","process":"laminate","text":"A butyl sealant, a rubbery compound that blocks moisture and gas, bonds the spacer to the glass. The second pane is pressed on, forming a closed cavity.","inputs":["adhesive"]},{"name":"Fill with argon","process":"fill","text":"Air in the cavity is swapped for argon, a heavier, poorer conductor of heat, and the cavity is closed.","inputs":["argon"]},{"name":"Seal the outer edge","process":"coat","text":"A secondary seal of silicone or similar sealant is applied around the edge to hold the unit together and keep out water.","inputs":["silicone"]}],"facts":["Fitting a second pane of glass to improve insulation began in Scotland, Germany and Switzerland in the 1870s.","A single pane of glass has an R-value of only around 1.","Low-emissivity glass has a thin metallic coating, usually on the second or third glass surface, that reflects infrared light."],"where":[],"whereNote":null,"sources":[{"title":"Insulating glass","url":"https://en.wikipedia.org/wiki/Insulating_glass"},{"title":"Window","url":"https://en.wikipedia.org/wiki/Window"},{"title":"Insulating glass units (US6238755)","url":"https://patents.google.com/patent/US6238755"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"down","name":"Down","kind":"raw","category":"farm","title":"How down is harvested","url":"https://assemblyline.org/make/down","stations":5,"upstream":0,"downstream":1,"depth":0,"dek":"Most comes from geese raised for meat. Top eiderdown fills 1,200 cubic inches per ounce, and costs a fortune.","answer":"Down is the fine layer under a bird's tough outer feathers, and its loose structure traps air. More than 99 percent is a by-product of meat plants, with China supplying some 70 percent. Processors dedust and wash it through several cycles, spin and steam it, blow it through a sorting chamber, and laboratories rate each lot by fill power.","aka":["down feathers","goose down","duck down","eiderdown"],"inputs":[],"uses":["down-jacket"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["down-jacket"],"steps":[{"name":"Collect at meat plants","process":"harvest","text":"Over 99% of goose and duck plumage is a by-product of meat packing, usually wet-plucked after slaughter. Live plucking also happens, including in Poland, Hungary and China, and has been condemned as cruel.","inputs":[]},{"name":"Dedust and wash","process":"wash","text":"Coarse dirt and dust come out first. Special washers then run the plumage through 6 to 8 cycles with a feather detergent, repeating until it meets hygiene rules. Rough handling here can damage the down.","inputs":[],"spec":"6 to 8 wash cycles"},{"name":"Spin and steam","process":"dry","text":"A centrifuge throws off the final rinse water. A pressure tank then steams the plumage, which one testing lab puts at 130 °C for 30 minutes, and it cools to room temperature.","inputs":[],"spec":"130 °C steam for 30 minutes"},{"name":"Blow it through a sorter","process":"separate","text":"Clean plumage enters a chamber with air jets below and floats over a row of open cubicles. Heavy feathers drop into the first, and pure down drifts to the far end. Blending then makes set mixes such as 90/10.","inputs":[]},{"name":"Rate the fill power","process":"inspect","text":"An ounce sits in a graduated cylinder under a small dropped weight. The volume below the weight, in cubic inches, is the fill power. Even 550 gives reasonably good insulation.","inputs":[]}],"facts":["Wild nests yield at most four tonnes of eiderdown a year, about 70% of it from Iceland.","World down production is estimated at 175,000 tonnes a year.","An 800-gram eiderdown duvet sold for about US$5,116 as of 2021."],"where":[{"place":"China","share":"about 70% of world supply"}],"whereNote":"Share of global down output as stated on Wikipedia; the article text gives no year.","sources":[{"title":"Washing and Sorting Down and Feathers, IDFL","url":"https://idfl.com/?p=585"},{"title":"How are down and feathers processed into bedding articles?, Textination","url":"https://textination.de/en/node/14519"},{"title":"Down Quality, PHD","url":"https://www.phdesigns.co.uk/down-quality"},{"title":"Down feather","url":"https://en.wikipedia.org/wiki/Down_feather"},{"title":"Duvet","url":"https://en.wikipedia.org/wiki/Duvet"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"down-jacket","name":"Down jacket","kind":"product","category":"textiles","title":"How down jackets are made","url":"https://assemblyline.org/make/down-jacket","stations":6,"upstream":47,"downstream":0,"depth":9,"dek":"The warmth in a down jacket comes from air trapped between clusters of soft under-feathers that have no stiff shaft.","answer":"A factory checks shell, lining and down against the specification, cuts the panels and sews or forms them into empty chambers called baffles. In a separate room, machines blow a pre-weighed charge of down through tubes into each chamber. Fill openings are sewn closed, sleeves, hood and zipper go on, and the jacket is shaken so the clusters spread evenly and loft before final inspection.","aka":["puffer jacket","puffer coat","padded jacket"],"inputs":["nylon","thread","down","zipper"],"uses":[],"grounds":["down","water","air","natural-gas","crude-oil","coal","copper-ore","zinc-ore","lead-ore","tin-ore","bauxite","sulfur","rock-salt","limestone","corn","sugarcane","sugar-beet"],"upstreamSlugs":["nylon","thread","down","zipper","benzene","nitric-acid","ammonia","polyester","water","brass","aluminum","naphtha","hydrogen","toluene","air","natural-gas","pet-plastic","copper","zinc","lead","tin","crude-oil","coal","petroleum-coke","alumina","p-xylene","ethylene","ethylene-glycol","copper-ore","oxygen","sulfuric-acid","zinc-ore","lead-ore","coke","tin-ore","bauxite","caustic-soda","lime","carbon-dioxide","sulfur","rock-salt","limestone","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Inspect the materials","process":"inspect","text":"Shell and lining are checked for shade, width, weight and visible defects. Down papers are matched against the order, and trims are tested before any cutting.","inputs":["nylon"]},{"name":"Cut panels, form baffles","process":"sew","text":"Panels are cut from patterns, and seams sewn with ultra-fine needles make up the chambers. Stitch and baffle sizes follow a quilting map.","inputs":["thread"]},{"name":"Blow in the down","process":"fill","text":"Down is weighed for each size, and a calibrated machine blows it through tubes into each chamber in a separated area that controls dust. Fill weights are recorded.","inputs":["down"]},{"name":"Close the openings","process":"sew","text":"A closing seam seals every fill opening, trapping the insulation inside for good.","inputs":["thread"]},{"name":"Attach sleeves and trims","process":"assemble","text":"Sleeves, hood, zipper, snaps and labels are joined to the body, and seams and measurements are checked.","inputs":["zipper"]},{"name":"Shake, loft and pack","process":"package","text":"The jacket is shaken hard to spread the clusters through their chambers, then cleaned, checked for full loft and packed.","inputs":[]}],"facts":["Down quality is measured in fill power, the number of cubic inches that one ounce of the down fills.","A mountaineer named George Finch is credited with wearing an early down jacket in 1922, made from balloon fabric and eiderdown."],"where":[],"whereNote":null,"sources":[{"title":"Ruiniu Jacket: Down jacket manufacturing, process and quality guide","url":"https://www.ruiniujacket.com/down-jacket-manufacturing:-a-complete-guide-to-down.html"},{"title":"Ginwen: How down jacket manufacturers produce winter jackets","url":"https://m.ginwenwear.com/blog/How-Down-Jacket-Manufacturers-Produce-Winter-Jackets_b22081"},{"title":"Down jacket","url":"https://en.wikipedia.org/wiki/Down_jacket"},{"title":"Down (feather)","url":"https://en.wikipedia.org/wiki/Down_(feather)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"dress-shirt","name":"Dress shirt","kind":"product","category":"textiles","title":"How dress shirts are made","url":"https://assemblyline.org/make/dress-shirt","stations":7,"upstream":43,"downstream":0,"depth":8,"dek":"Shirt collars and cuffs used to be separate pieces, attached with studs so they could be washed on their own.","answer":"A dress shirt is cut from a fine woven cotton cloth in about a dozen pieces: two front panels, a back, two sleeves, a collar, cuffs and a placket. Fusible interlining is bonded to the collar and cuffs in a fusing machine. Operators sew the pieces, then buttons and buttonholes are added, threads are trimmed, and the shirt is ironed and folded.","aka":["button-up shirt","button-front shirt","formal shirt"],"inputs":["cotton-yarn","adhesive","thread","button"],"uses":[],"grounds":["raw-cotton","water","crude-oil","natural-gas","air","sulfur","rock-salt","coal","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["cotton-yarn","adhesive","thread","button","raw-cotton","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","polyester","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","pet-plastic","naphtha","natural-gas","air","sulfur","benzene","rock-salt","p-xylene","ethylene-glycol","toluene","oxygen","carbon-dioxide","coal","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Spin fine cotton yarn","process":"spin","text":"Cotton fibers are combed and twisted into thin, even yarn. Dress-shirt cloth needs smooth yarn, because every lump would show as a rough patch on the surface.","inputs":["cotton-yarn"]},{"name":"Weave the poplin cloth","process":"weave","text":"Looms interlace the yarn over and under in a tight pattern. Dress-shirt weaves are fine and flat, so the cloth drapes cleanly and takes a crisp crease.","inputs":[]},{"name":"Dye and finish the cloth","process":"dye","text":"White cloth is bleached, and colored or striped cloth is dyed or woven from dyed yarn. A finishing treatment can be added so the shirt wrinkles less after washing.","inputs":[]},{"name":"Cut the shirt pieces","process":"cut","text":"Cloth is checked and sorted into shade lots, then laid in layers on a flat table and cut around marked patterns. Stripes and checks have to line up across the seams, so those pieces are cut with extra care.","inputs":[]},{"name":"Fuse the collar stiffening","process":"laminate","text":"Fusible interlining is cut to the shape of the collar and cuffs and bonded to them in a fusing machine. This is why a good collar stands up and holds its points.","inputs":["adhesive"]},{"name":"Stitch the shirt together","process":"sew","text":"Sewing operators join the yoke, sleeves and sides, attach the collar and cuffs, and hem the bottom. The placket down the front is folded and stitched to carry the buttonholes.","inputs":["thread"]},{"name":"Add buttons and iron","process":"assemble","text":"A machine cuts the buttonholes on the collar, cuffs and placket, and another sews on the buttons. Loose thread ends are trimmed, stains are removed, and the shirt is ironed, folded and bagged.","inputs":["button"]}],"facts":["Early dress shirts had detachable collars and cuffs, held on with studs or buttons so the parts that got dirty could be changed without washing the whole shirt.","Factories sort cloth into bands of matching shade and cut each band separately, so no shirt ends up with slightly different colors in its panels."],"where":[],"whereNote":null,"sources":[{"title":"Dress shirt","url":"https://en.wikipedia.org/wiki/Dress_shirt"},{"title":"Shirt manufacturing process (Online Clothing Study)","url":"https://www.onlineclothingstudy.com/2014/06/shirt-manufacturing-process.html"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"drill-bit","name":"Drill bit","kind":"product","category":"hardware","title":"How drill bits are made","url":"https://assemblyline.org/make/drill-bit","stations":7,"upstream":32,"downstream":0,"depth":5,"dek":"Cheap twist drills are heated, flattened and twisted. Better ones have their spiral ground out of hardened solid rod.","answer":"A ground twist drill starts as a solid rod of high-speed steel, cut to about its finished length. The rod is ground to diameter, hardened, blasted clean, then fed to a machine that grinds each flute in turn. A wheel forms the point last, flatter for harder metals. Cheaper rolled bits skip the flute grinding: hot steel is forged flat and twisted instead.","aka":["twist drill","twist bit"],"inputs":["steel","tungsten","titanium"],"uses":[],"grounds":["tungsten-ore","titanium-ore","iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","rock-salt","coal","quartz","timber","crude-oil","sulfur"],"upstreamSlugs":["steel","tungsten","titanium","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","tungsten-ore","hydrogen","titanium-ore","chlorine","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","rock-salt","coal","quartz","charcoal","timber","crude-oil","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Cut the steel rod","process":"cut","text":"Most modern twist drills use high-speed steel, a high-carbon tool steel that keeps its hardness up to a red heat of around 650 °C. Bar or rod is cut into lengths close to the finished tool.","inputs":["steel","tungsten"],"spec":"around 650 °C red hardness"},{"name":"Grind the outside diameter","process":"grind","text":"The cut rod's outside is ground to the specified sizes for the barrel and the shank, before any of the cutting geometry exists.","inputs":[]},{"name":"Harden the rod","process":"heat-treat","text":"Heat treatment makes the rod harder. Blasting with particles or a chemical wash then strips off the thin film of deposits it leaves behind.","inputs":[]},{"name":"Grind the flutes","process":"grind","text":"A flute grinding machine cuts one groove, the rod turns half a circle in its chuck, and the machine cuts the second. These grooves carry chips out of the hole.","inputs":[]},{"name":"Or forge and twist","process":"forge","text":"Rolled bits replace the flute grinding with forging. The steel is heated, flattened and twisted to shape, a much shorter process. They come out cheaper, but often more brittle and less accurate.","inputs":[]},{"name":"Shape the point","process":"grind","text":"A contoured wheel forms the flank surfaces at the tip. Rolled bits often get a 118° tip, while ground bits for hard metal get a flatter 135°, sometimes split so they start without a pilot hole.","inputs":[]},{"name":"Coat the surface","process":"deposit","text":"Some high-speed steel bits get a titanium nitride coating, which adds strength and lowers friction when drilling hard materials.","inputs":["titanium"]}],"facts":["Titanium nitride is a very hard coating that can extend the cutting life of a high-speed steel drill by three or more times.","Ordinary carbon tool steel loses its cutting ability at 200 to 500 °C, which is why drill makers moved to high-speed steel.","Massachusetts inventor Stephen A. Morse came up with the twist drill in 1861, and its basic form has barely changed."],"where":[],"whereNote":null,"sources":[{"title":"Drill bit","url":"https://en.wikipedia.org/wiki/Drill_bit"},{"title":"Twist Drill Bits, DART Tool Group","url":"https://www.darttoolgroup.com/what-are-twist-drill-bits"},{"title":"US5011342A: Twist drill","url":"https://patents.google.com/patent/US5011342A/en"},{"title":"Guide to Materials and Shapes of Twist Drills, GSR","url":"https://www.gsrthreads.com/news/guide-to-materials-and-shapes-of-twist-drills.html"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"drum-kit","name":"Drum kit","kind":"product","category":"play","title":"How drum kits are made","url":"https://assemblyline.org/make/drum-kit","stations":8,"upstream":65,"downstream":0,"depth":9,"dek":"A drum kit packs several drums and cymbals into one player's reach, a combination that began in the 1860s.","answer":"A drum kit combines wooden-shelled drums, plastic heads, metal hoops and cymbals made of copper alloy. Wood plies are bent into cylinders, edges are cut, heads are stretched over hoops, and lugs and rims are bolted on. Cymbals are cast, hammered and turned on a lathe. The kit is assembled and tuned.","aka":["drum set","drums","trap set"],"inputs":["plywood","adhesive","pet-plastic","aluminum","bronze","steel","steel-wire"],"uses":[],"grounds":["timber","water","crude-oil","coal","natural-gas","bauxite","copper-ore","air","tin-ore","iron-ore","limestone","dolomite","manganese-ore","sulfur","rock-salt","corn","quartz","sugarcane","sugar-beet"],"upstreamSlugs":["plywood","adhesive","pet-plastic","aluminum","bronze","steel","steel-wire","timber","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","p-xylene","ethylene","ethylene-glycol","crude-oil","coal","petroleum-coke","alumina","copper","tin","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","hydrogen","naphtha","natural-gas","carbon-dioxide","bauxite","copper-ore","air","tin-ore","coke","iron-ore","limestone","dolomite","silicon","propane","manganese-ore","sulfur","benzene","rock-salt","corn","yeast","quartz","charcoal","toluene","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Bend the plies into shells","process":"laminate","text":"Thin sheets of wood are glued and wound or pressed into cylinders. A shell is a thin wooden tube that gives each drum its voice.","inputs":["plywood","adhesive"]},{"name":"Cut the bearing edges","process":"machine","text":"A machine cuts a precise angled edge on each rim of the shell, where the drumhead rests. Flat, true edges let the head vibrate evenly.","inputs":[]},{"name":"Stretch the drumheads","process":"assemble","text":"Plastic film is stretched over metal hoops. The batter head takes the stick, and a thinner head underneath answers it.","inputs":["pet-plastic","aluminum"]},{"name":"Cast the cymbal blanks","process":"cast","text":"A copper alloy is melted and cast, then rolled into round plates. Cymbals are thin plates of copper alloy.","inputs":["bronze"]},{"name":"Hammer and lathe the cymbals","process":"forge","text":"Cymbals are hammered to give them their character, then turned on a lathe to thin them out and cut fine grooves. Each plate is shaped into a bowl with a raised central bell.","inputs":[]},{"name":"Plate the hardware","process":"coat","text":"Stands, hoops and lugs are made of steel and chrome-plated to resist wear.","inputs":["steel"]},{"name":"Fit snare wires","process":"assemble","text":"A snare drum has a bed of stiff metal wires held against the bottom head. When the top head is hit, the wires buzz against it.","inputs":["steel-wire"]},{"name":"Tension and tune","process":"inspect","text":"Tension rods are tightened in turn round each head until the pitch is even.","inputs":[]}],"facts":["Cymbals are the oldest idiophones in music, and some were used in the Bronze Age.","By the 1860s, percussionists had started combining multiple drums into a single kit.","William Ludwig developed an early low-mounted \"sock\" cymbal, which led to the modern hi-hat."],"where":[],"whereNote":null,"sources":[{"title":"Drum kit","url":"https://en.wikipedia.org/wiki/Drum_kit"},{"title":"Cymbal","url":"https://en.wikipedia.org/wiki/Cymbal"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"drumstick","name":"Drumstick","kind":"product","category":"play","title":"How drumsticks are made","url":"https://assemblyline.org/make/drumstick","stations":8,"upstream":30,"downstream":0,"depth":8,"dek":"The world's biggest drumstick maker skips the lathe and grinds its sticks to shape underwater.","answer":"Most drumsticks start as straight-grained hickory, kiln-dried and sawn into square blanks. At Vic Firth's Maine plant the blanks skip the lathe and are ground under water in several abrasive stages, which keeps them cool and straight. Finished sticks are paired by weight, color and the pitch they ring at when struck, then stamped and sealed.","aka":["drum sticks","sticks"],"inputs":["lumber","nylon","adhesive"],"uses":[],"grounds":["timber","water","air","natural-gas","crude-oil","coal","sulfur","rock-salt"],"upstreamSlugs":["lumber","nylon","adhesive","timber","benzene","nitric-acid","ammonia","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","naphtha","hydrogen","toluene","air","natural-gas","ethylene","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","crude-oil","coal","sulfur","rock-salt"],"downstreamSlugs":[],"steps":[{"name":"Kiln-dry the hickory","process":"dry","text":"Hickory is the usual choice, with maple second and oak third. Vic Firth's plant buys hickory from Tennessee and kiln-dries it, and in 2008 it went through 75 pallets a day.","inputs":["lumber"]},{"name":"Reject wavy grain","process":"inspect","text":"Workers examine the wood again and again for defects. Only straight grain passes. Waves break up the long fibers and weaken a stick, so figured wood that a furniture maker would prize gets thrown out.","inputs":[]},{"name":"Cut square blanks","process":"cut","text":"Planks are cut into square strips a little longer and thicker than the finished stick.","inputs":[]},{"name":"Grind under water","process":"grind","text":"Abrasive wheels take the blank down in several stages, all under water. The maker calls this very accurate and very fast, and the water stops the machines from burning the stick. Each shaft tapers toward a slightly convex shoulder and then the tip.","inputs":[]},{"name":"Form the tip","process":"grind","text":"The tip, or bead, is shaped from the same piece of wood. Common shapes are acorn, barrel, oval, teardrop, pointed and round.","inputs":[]},{"name":"Glue on a nylon tip","process":"assemble","text":"Some sticks get a nylon tip instead, a design on sale since 1958. Nylon tips last longer and give a brighter sound on cymbals.","inputs":["nylon","adhesive"]},{"name":"Pair sticks by tone","process":"inspect","text":"Sticks are sorted by color, weight and the frequency they sound when struck, so a pair feels alike in the hand. A machine now does this.","inputs":[]},{"name":"Stamp and finish","process":"coat","text":"The logo and a size such as 7A or 5B are stamped on, and the stick typically gets a clear finish.","inputs":[]}],"facts":["Vic Firth got the idea for matching sticks by pitch after dropping a bag of them in his basement and hearing different notes.","A wavy hickory or tiger maple grain that looks beautiful on furniture is junk to a drumstick maker, because it makes the stick weak.","Nylon tips were introduced in 1958, and acetal tips arrived in the 1970s."],"where":[],"whereNote":null,"sources":[{"title":"Drumroll, please: Newport company continues to thrive","url":"https://www.sunjournal.com/?p=8078836"},{"title":"Stick to-itiveness","url":"https://www.bangordailynews.com/2008/10/31/news/stick-toitiveness/"},{"title":"Drum stick","url":"https://en.wikipedia.org/wiki/Drum_stick"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"drywall","name":"Drywall","kind":"product","category":"minerals","title":"How drywall is made","url":"https://assemblyline.org/make/drywall","stations":7,"upstream":15,"downstream":0,"depth":5,"dek":"Some of the gypsum in drywall is scrubbed out of coal-plant smoke.","answer":"Drywall is a core of gypsum plaster sandwiched between two sheets of heavy paper. Gypsum is heated to drive off water, mixed back into a foamy slurry with additives, and spread between paper on a moving line. When the core sets, the board is cut and dried in a large gas-fired chamber.","aka":["plasterboard","gypsum board","sheetrock","wallboard"],"inputs":["gypsum","water","paper"],"uses":[],"grounds":["gypsum","water","kaolin","limestone","timber","rock-salt","air","natural-gas"],"upstreamSlugs":["gypsum","water","paper","wood-pulp","kaolin","limestone","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","rock-salt","air","hydrogen","natural-gas"],"downstreamSlugs":[],"steps":[{"name":"Mine or capture gypsum","process":"mine","text":"Raw gypsum is dug from quarries. Increasingly it is also recovered as a by-product, when coal power plants scrub sulfur from their smokestacks with limestone and produce so-called FGD gypsum.","inputs":["gypsum"]},{"name":"Cook off the water","process":"react","text":"Raw gypsum, a calcium sulfate dihydrate, is heated to drive off its chemically bound water, then slightly rehydrated into the hemihydrate form known as plaster.","inputs":[]},{"name":"Mix the slurry","process":"mix","text":"The plaster is blended with water, paper or glass fiber, a plasticizer, a foaming agent, ground gypsum crystals as an accelerator, and starch as a retarder. Additives can add mildew resistance or fire resistance.","inputs":["water"]},{"name":"Sandwich it in paper","process":"laminate","text":"The wet core is formed between two sheets of heavy paper or fiberglass mats on a moving line. Foaming leaves tiny pores that reduce weight.","inputs":["paper"]},{"name":"Let the core set","process":"dry","text":"The gypsum rehydrates and locks into a rigid mass while the board travels down the line.","inputs":[]},{"name":"Dry it in the chamber","process":"dry","text":"Large drying chambers, typically gas-fired, drive off the excess water. Drying 1,000 square feet of wallboard takes between 1,750,000 and 2,490,000 BTU.","inputs":[],"spec":"1,750,000–2,490,000 BTU per 1,000 sq ft"},{"name":"Cut and stack","process":"cut","text":"The continuous board is cut into sheets, stacked and packaged for shipment. Up to 12% of drywall is wasted in manufacturing and installation, and some makers take scrap back to recycle.","inputs":[]}],"facts":["When drywall is heated, the water in gypsum is released as vapor in a reaction that absorbs heat, which slows a fire.","The Sackett Board of 1890 was made by layering plaster within four plies of wool felt paper."],"where":[],"whereNote":null,"sources":[{"title":"Drywall","url":"https://en.wikipedia.org/wiki/Drywall"},{"title":"Gypsum","url":"https://en.wikipedia.org/wiki/Gypsum"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"duct-tape","name":"Duct tape","kind":"product","category":"plastics","title":"How duct tape is made","url":"https://assemblyline.org/make/duct-tape","stations":6,"upstream":41,"downstream":0,"depth":9,"dek":"Duct tape is a layered sandwich of plastic film, loose cloth mesh and rubbery glue, and it was first made to seal ammo boxes.","answer":"Tape making begins with the glue. Blocks of natural rubber and plastic resin pellets are mixed in a Banbury mixer to the consistency of pizza dough, then heated in a sigma kneader. Film and cotton mesh feed into a coating unit that pushes adhesive through the cloth and onto the film. The wide roll is slit and rewound.","aka":["duck tape","gaffer tape","cloth tape"],"inputs":["natural-latex","plastic","polyethylene","cotton-fabric","adhesive","cardboard"],"uses":[],"grounds":["natural-latex","natural-gas","water","crude-oil","raw-cotton","corn","timber","air","sulfur","rock-salt","limestone","coal"],"upstreamSlugs":["natural-latex","plastic","polyethylene","cotton-fabric","adhesive","cardboard","naphtha","natural-gas","ethylene","propylene","cotton-yarn","corn-starch","water","acrylic","epoxy","polyurethane","paraffin-wax","wood-pulp","crude-oil","hydrogen","raw-cotton","corn","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","timber","lime","oxygen","hydrogen-peroxide","air","sulfur","benzene","rock-salt","limestone","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Mix rubber and resin","process":"mix","text":"Large blocks of natural rubber break down with pellets of plastic resin in a Banbury mixer. Spiral blades work the mass to the feel of pizza dough, and the resin adds tack that rubber lacks.","inputs":["natural-latex","plastic"]},{"name":"Heat in a kneader","process":"knead","text":"A sigma kneader warms the rubber and resin and processes it further. This adhesive is usually the most expensive layer in the tape.","inputs":[]},{"name":"Feed film and mesh","process":"assemble","text":"A polyethylene film and a cotton mesh run in together. The mesh gives strength and lets you tear by hand. Better tapes have more strands per inch.","inputs":["polyethylene","cotton-fabric"]},{"name":"Coat through the cloth","process":"laminate","text":"The coating unit presses a generous layer of adhesive through the cloth onto the film, bonding the three layers. Lamination under heavy pressure is the most common method.","inputs":["adhesive"]},{"name":"Or co-extrude it","process":"extrude","text":"Some makers meld polyethylene, cloth and adhesive in one hot process. The tape is thinner and stronger, lies flatter and shows a dimpled surface. Shurtape is one of two US makers using it.","inputs":[]},{"name":"Slit and rewind","process":"cut","text":"The large roll is unwrapped, sliced to width and rerolled on cardboard cores before packing and shipping.","inputs":["cardboard"]}],"facts":["During World War II, Revolite, a division of Johnson & Johnson, developed a tape from rubber-based adhesive on duck cloth that resisted water and sealed ammunition cases.","The Oxford English Dictionary records duck tape in use since 1899 and duct tape since 1965.","Duct tape is often confused with gaffer tape, which is designed to be non-reflective and to come off cleanly."],"where":[],"whereNote":null,"sources":[{"title":"Gizmodo: How duct tape fixes the world","url":"https://gizmodo.com/5941517/how-duct-tape-fixes-the-world"},{"title":"Yale Scientific: How duct tape is made","url":"https://www.yalescientific.org/?p=2913"},{"title":"Journal of Light Construction: More than you ever wanted to know about duct tape","url":"https://www.jlconline.com/tools/fastening-tools/power-tools/more-than-you-ever-wanted-to-know-about-duct-tape_o/"},{"title":"Duct tape","url":"https://en.wikipedia.org/wiki/Duct_tape"},{"title":"Adhesive","url":"https://en.wikipedia.org/wiki/Adhesive"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"dumbbell","name":"Dumbbell","kind":"product","category":"play","title":"How dumbbells are made","url":"https://assemblyline.org/make/dumbbell","stations":8,"upstream":52,"downstream":0,"depth":8,"dek":"One dumbbell patent presses rubber sheet around each iron head at about 170 °C, one head at a time.","answer":"Fixed rubber dumbbells begin as cast iron heads with a hole through the center and a separate handle knurled for grip. Heads and handle are joined into one piece, then a head goes into a mold packed with rubber sheet and is pressed hot under a hydraulic ram. The bar is flipped so the other head gets the same treatment, and a blade trims the flash.","aka":["hex dumbbell","free weight","hand weight"],"inputs":["pig-iron","steel","chromium","rubber"],"uses":[],"grounds":["iron-ore","limestone","air","chromite","water","natural-latex","sulfur","coal","dolomite","manganese-ore","natural-gas","rock-salt","trona","crude-oil","quartz","timber","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["pig-iron","steel","chromium","rubber","iron-ore","coke","limestone","air","magnesium","steel-scrap","oxygen","lime","manganese","argon","chromite","soda-ash","water","aluminum","natural-latex","synthetic-rubber","carbon-black","sulfur","coal","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","rock-salt","ammonia","carbon-dioxide","trona","crude-oil","petroleum-coke","alumina","naphtha","benzene","ethylene","styrene","quartz","charcoal","timber","corn","yeast","bauxite","caustic-soda","hydrogen","toluene","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cast the hex heads","process":"cast","text":"Iron is cast into hexagons, each with a hole straight through it for the handle. One patent complains that weight and size are hard to control during casting, and that rejects run high.","inputs":["pig-iron"]},{"name":"Knurl the handle","process":"machine","text":"The handle is machined separately and its grip is knurled into a non-slip texture. One maker contours the bar to the palm.","inputs":["steel"]},{"name":"Chrome the handle","process":"coat","text":"The handle takes a chrome finish on rubber hex models such as Body-Solid's.","inputs":["chromium"]},{"name":"Weld heads to bar","process":"weld","text":"In one Chinese patent the handle and both heads are welded into one solid body. Another patent threads the handle through the plate instead, after its coating has gone on.","inputs":[]},{"name":"Pack rubber around iron","process":"assemble","text":"The bar is clamped upright in a slot on the machine table with one head on top. A sleeve goes around that head and sheet rubber is stuffed into the gap until it overflows. Molded letters and numbers for the weight marking sit in a top cap.","inputs":["rubber"]},{"name":"Hot-press the cover","process":"press","text":"A hydraulic ram pushes the top cap down, and the rubber flows tight around the iron while the marking fuses into its end. Pressure is released in steps to let air out, up to 22 times in one patent.","inputs":[],"spec":"one patent: 170 °C, 100 MPa, 15 minutes"},{"name":"Flip and repeat","process":"press","text":"The ram retracts, the bar slides out and the mold parts come off in order. The bar is turned upside down and the second head goes through the same packing and pressing.","inputs":[]},{"name":"Trim the flash","process":"cut","text":"A blade slices off the thin fin of rubber squeezed out at the mold joints, leaving the finished dumbbell.","inputs":[]}],"facts":["The ancestor of the dumbbell was the halteres, weights that ancient Greek athletes held to jump farther.","The name comes from bell-ringing. In the 17th century, silent weighted devices copied the motion of a church bell so people could exercise at home.","Cheap fixed dumbbells may be a plastic shell filled with concrete instead of iron."],"where":[],"whereNote":null,"sources":[{"title":"CN103585739A, Dumbbell, rubber coating machine for dumbbell and dumbbell production process","url":"https://patents.google.com/patent/CN103585739A/en"},{"title":"CN102189256A, Process for manufacturing dumbbell and barbell products","url":"https://patents.google.com/patent/CN102189256A/en"},{"title":"US20050054496A1, Coated weight plates, dumbbells and method of manufacture","url":"https://patents.google.com/patent/US20050054496A1/en"},{"title":"Rubber Hex Dumbbells, Body-Solid","url":"https://bodysolid.com/home/SDR/Rubber_Hex_Dumbbells/Features"},{"title":"Dumbbell","url":"https://en.wikipedia.org/wiki/Dumbbell"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"durum-wheat","name":"Durum wheat","kind":"raw","category":"farm","title":"How durum wheat is grown","url":"https://assemblyline.org/make/durum-wheat","stations":3,"upstream":0,"downstream":2,"depth":0,"dek":"Durum is the hardest wheat there is, which is why it makes pasta and not light bread.","answer":"Durum is a hard wheat with four sets of chromosomes, bred from emmer wheat thousands of years ago. It makes up only 5 to 8 percent of the world's wheat. Farmers grow it for its hard, glassy kernels, which mills turn into coarse yellow semolina.","aka":["durum","macaroni wheat","pasta wheat"],"inputs":[],"uses":["pasta","semolina"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["pasta","semolina"],"steps":[{"name":"Sow the hard wheat","process":"grow","text":"Durum grows like other wheats but has a different heritage, with four sets of chromosomes rather than six. Italy is a major production area.","inputs":[]},{"name":"Combine the ripe heads","process":"harvest","text":"Harvesters cut the crop and thresh out the grain once the heads are ripe. Buyers check the share of hard, vitreous kernels, which sets the grade.","inputs":[]},{"name":"Clean and send to the mill","process":"separate","text":"Chaff and stones are cleaned out before the grain ships to a mill. Durum resists milling more than any other wheat, so it comes out coarse and not as a fine flour.","inputs":[]}],"facts":["The word durum is Latin for hard.","Durum is the second-most cultivated wheat species, though it is only 5 to 8 percent of global wheat production.","Commercial dry pasta is made almost exclusively from durum semolina."],"where":[],"whereNote":null,"sources":[{"title":"Durum","url":"https://en.wikipedia.org/wiki/Durum"},{"title":"Semolina","url":"https://en.wikipedia.org/wiki/Semolina"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"e-reader","name":"E-reader","kind":"product","category":"electronics","title":"How e-readers are made","url":"https://assemblyline.org/make/e-reader","stations":6,"upstream":102,"downstream":0,"depth":9,"dek":"An e-reader screen uses no power to hold a page, so the battery can last for weeks.","answer":"An e-reader screen is a film of microcapsules holding white and black charged particles, laid over a grid of transistors. An electric field pulls the right particles to the surface of each dot. The film is cut and fixed to the transistor grid with a protective sheet and driver, wired to a circuit board with a battery, and fitted in a case.","aka":["ebook reader","Kindle","e-ink reader"],"inputs":["titanium-dioxide","adhesive","plastic","glass","printed-circuit-board","microchip","lithium-ion-cell","led","abs-plastic"],"uses":[],"grounds":["titanium-ore","water","natural-gas","silica-sand","limestone","air","rock-salt","coal","sulfur","crude-oil","trona","copper-ore","quartz","tin-ore","gold-ore","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","iron-ore","bauxite","zinc-ore","corn","lead-ore","silver-ore","dolomite","timber","sugarcane","sugar-beet"],"upstreamSlugs":["titanium-dioxide","adhesive","plastic","glass","printed-circuit-board","microchip","lithium-ion-cell","led","abs-plastic","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","naphtha","natural-gas","ethylene","propylene","silica-sand","soda-ash","limestone","copper","fiberglass","photoresist","solder","silicon-wafer","tin","aluminum","gold","lithium-carbonate","cobalt","nickel","manganese","synthetic-graphite","steel","gallium","indium","ammonia","hydrogen","air","benzene","styrene","pigment","rock-salt","coal","sulfur","methanol","phenol","acetone","caustic-soda","nitric-acid","crude-oil","carbon-dioxide","lime","trona","copper-ore","phenolic-resin","lead","silver","polysilicon","quartz","argon","tin-ore","petroleum-coke","alumina","gold-ore","zinc","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","iron-ore","pig-iron","magnesium","steel-scrap","bauxite","zinc-ore","toluene","carbon-black","corn","yeast","formaldehyde","lead-ore","silver-ore","silicon","hydrochloric-acid","trichlorosilane","nitrogen","dolomite","propane","molasses","charcoal","timber","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Fill the capsules","process":"mix","text":"Microcapsules about the diameter of a human hair are filled with a clear fluid. Inside are negatively charged white particles, often titanium dioxide, and positively charged black ones.","inputs":["titanium-dioxide"]},{"name":"Coat the film","process":"coat","text":"The capsules are coated onto a plastic film with a clear front electrode. The film is rolled out in long sheets and cut to size.","inputs":["adhesive","plastic"]},{"name":"Build the transistor grid","process":"deposit","text":"A sheet of glass or plastic gets a grid of thin-film transistors, one for each dot. The grid lets the device set the voltage over each pixel separately.","inputs":["glass"]},{"name":"Laminate film to grid","process":"laminate","text":"The ink film is bonded onto the transistor grid and a protective sheet goes on top, with a driver chip and connector to finish the display module. A field of one polarity brings white particles up, and the other brings black.","inputs":["adhesive"]},{"name":"Assemble the electronics","process":"assemble","text":"A small board with a low-power processor, memory and a wireless chip is wired to the display, along with a lithium-ion battery. A front light can be added for reading in the dark.","inputs":["printed-circuit-board","microchip","lithium-ion-cell","led"]},{"name":"Seal in the case","process":"assemble","text":"The screen and board are fitted into a plastic or magnesium case, and the unit is tested for display flaws before packing.","inputs":["abs-plastic"]}],"facts":["The Sony Librie, released in 2004, was the first e-reader to use electronic paper.","The Amazon Kindle sold out within five and a half hours of its release in 2007."],"where":[],"whereNote":null,"sources":[{"title":"E-reader","url":"https://en.wikipedia.org/wiki/E-reader"},{"title":"Electronic paper","url":"https://en.wikipedia.org/wiki/Electronic_paper"},{"title":"How it works (E Ink)","url":"https://www.eink.com/tech/detail/How_it_works"},{"title":"E Ink film","url":"https://eink.com/e-ink-film.html"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"egg-carton","name":"Egg carton","kind":"product","category":"wood-paper","title":"How egg cartons are made","url":"https://assemblyline.org/make/egg-carton","stations":6,"upstream":14,"downstream":0,"depth":5,"dek":"A pulp egg carton is recycled newspaper that was sucked onto a wire mold and baked dry.","answer":"Recycled paper is broken down in water into a thin fiber slurry. A mesh mold shaped like a tray of egg cups is dunked in it, and a vacuum pulls the fibers tight against the mesh. The damp pulp shell is then dried in an oven or between heated dies, which also makes the lid smoother and firmer.","aka":["egg box","egg tray"],"inputs":["paper","water"],"uses":[],"grounds":["water","kaolin","limestone","timber","rock-salt","air","natural-gas"],"upstreamSlugs":["paper","water","wood-pulp","kaolin","limestone","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","rock-salt","air","hydrogen","natural-gas"],"downstreamSlugs":[],"steps":[{"name":"Break paper into slurry","process":"mix","text":"Old paper and newsprint are churned in water until they separate into a runny slush of loose fibers.","inputs":["paper","water"]},{"name":"Vacuum fibers onto a mesh","process":"mold","text":"A fine wire mesh in the shape of the carton dips into the slurry, or has slurry sprayed at it. A vacuum behind the mesh pulls water through, leaving a mat of fibers where the water was.","inputs":[]},{"name":"Transfer the wet shell","process":"assemble","text":"The damp pulp shell is lifted off the mesh and carried toward the drying stage while it is still soft.","inputs":[]},{"name":"Dry it firm","process":"dry","text":"Ovens carry the damp shells through hot air until the water is gone, and each carton shrinks and stiffens as it dries.","inputs":[]},{"name":"Press the lid smooth","process":"press","text":"Some cartons are pressed between heated mating dies while they dry. This gives the lid a smoother, firmer surface that takes printing better than the rough egg cups.","inputs":[]},{"name":"Stack and ship","process":"package","text":"The finished cartons nest inside each other for the trip to the egg packer.","inputs":[]}],"facts":["A British Columbia newspaper editor, Joseph Coyle, invented the egg carton in 1911 to settle a dispute over a farmer's broken eggs.","The hinged lid that lets cartons of six or twelve stack was added in the 1950s by H.G. Bennett, working for the company Hartmann.","Each dimple in the carton isolates its egg from the neighbors and soaks up shock, which keeps shells from cracking."],"where":[],"whereNote":null,"sources":[{"title":"Egg carton","url":"https://en.wikipedia.org/wiki/Egg_carton"},{"title":"Molded pulp","url":"https://en.wikipedia.org/wiki/Molded_pulp"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"eggs","name":"Eggs","kind":"raw","category":"farm","title":"How eggs are produced on a farm","url":"https://assemblyline.org/make/eggs","stations":3,"upstream":0,"downstream":4,"depth":0,"dek":"A wild jungle fowl lays about a dozen eggs a year, while a modern laying hen can lay more than three hundred.","answer":"Commercial eggs come from laying hens bred over thousands of years to lay year-round. The hens live in large flocks, and their eggs are gathered, checked and graded by size and freshness. Candling with a bright light shows the size of the air cell, which grows as an egg ages and sets its grade.","aka":["chicken eggs","hen eggs","egg farming","egg production","laying hens"],"inputs":[],"uses":["mayonnaise","donut","imitation-crab","cake-mix"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["mayonnaise","donut","imitation-crab","cake-mix"],"steps":[{"name":"Keep laying hens","process":"grow","text":"The wild Asian fowl that chickens descend from lay about a dozen eggs each breeding season. Selective breeding now gives hens that lay more than three hundred eggs a year and lay all year round.","inputs":[]},{"name":"Gather the eggs","process":"harvest","text":"Eggs are collected from the flock. A single large egg factory can ship millions of eggs. Global production reached 91 million tonnes in 2023.","inputs":[]},{"name":"Candle and grade","process":"inspect","text":"Eggs are held in front of a bright light to check quality. The air cell at the larger end grows as the egg cools and ages. A very fresh egg has a small air cell and earns grade AA, and a bigger air cell lowers the grade.","inputs":[]}],"facts":["The chicken was most likely first domesticated for its eggs before 7500 BCE.","A blood spot on a yolk is not conclusive proof that an egg was fertilized."],"where":[{"place":"China","share":"31.3 million tonnes"},{"place":"United States","share":"6.3 million tonnes"},{"place":"India","share":"4.8 million tonnes"},{"place":"Mexico","share":"2.8 million tonnes"},{"place":"Japan","share":"2.6 million tonnes"}],"whereNote":"2017, chicken eggs produced, of a world total of 80.1 million tonnes.","sources":[{"title":"Egg as food","url":"https://en.wikipedia.org/wiki/Egg_as_food"},{"title":"Chicken","url":"https://en.wikipedia.org/wiki/Chicken"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"electric-car","name":"Electric car","kind":"product","category":"machines","title":"How electric cars are made","url":"https://assemblyline.org/make/electric-car","stations":8,"upstream":130,"downstream":0,"depth":10,"dek":"An electric car has no engine, but the battery pack under its floor is the heaviest single part.","answer":"An electric car is built much like any car: pressed panels welded into a shell, painted, then fitted out on an assembly line. The difference is underneath. In place of an engine and fuel tank, the plant fits an electric drive unit and a large battery pack in the floor, along with chargers and power electronics.","aka":["EV","battery electric vehicle","plug-in car"],"inputs":["sheet-steel","aluminum","paint","electric-motor","copper-wire","ev-battery","printed-circuit-board","microchip","windshield","tire","airbag"],"uses":[],"grounds":["crude-oil","coal","water","natural-latex","sulfur","zinc-ore","air","bauxite","titanium-ore","iron-ore","copper-ore","silica-sand","limestone","quartz","tin-ore","gold-ore","dolomite","manganese-ore","natural-gas","rock-salt","lithium-brine","spodumene","cobalt-ore","nickel-ore","trona","lead-ore","silver-ore","soybeans","rapeseed","clay","corn","sugarcane","timber","sugar-beet"],"upstreamSlugs":["sheet-steel","aluminum","paint","electric-motor","copper-wire","ev-battery","printed-circuit-board","microchip","windshield","tire","airbag","steel","zinc","crude-oil","coal","petroleum-coke","alumina","water","titanium-dioxide","pigment","acrylic","tin-can","epoxy","ball-bearing","copper","lithium-ion-cell","adhesive","fiberglass","photoresist","solder","silicon-wafer","oxygen","tin","gold","window-glass","ink","pvb","synthetic-rubber","natural-latex","carbon-black","sulfur","steel-wire","brass","nylon","polyester","silicone","thread","pig-iron","magnesium","steel-scrap","lime","manganese","argon","zinc-ore","air","sulfuric-acid","bauxite","caustic-soda","titanium-ore","chlorine","coke","iron-ore","propylene","ammonia","methanol","tinplate","lacquer","phenol","acetone","copper-ore","lithium-carbonate","cobalt","nickel","synthetic-graphite","polyethylene","polyurethane","paraffin-wax","silica-sand","limestone","soda-ash","phenolic-resin","lead","silver","polysilicon","quartz","tin-ore","gold-ore","dolomite","nitrogen","hydrogen","vegetable-oil","ethanol","polyvinyl-alcohol","plasticizer","naphtha","benzene","ethylene","styrene","nitric-acid","pet-plastic","silicon","hydrochloric-acid","propane","manganese-ore","natural-gas","rock-salt","lithium-brine","spodumene","cobalt-ore","nickel-ore","carbon-dioxide","trona","formaldehyde","lead-ore","silver-ore","trichlorosilane","soybeans","rapeseed","hexane","clay","corn","sugarcane","yeast","toluene","p-xylene","ethylene-glycol","charcoal","timber","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Press the body panels","process":"stamp","text":"Presses shape flat sheet into panels. Because the battery is heavy, makers often choose lighter aluminum for some parts to offset it.","inputs":["sheet-steel","aluminum"]},{"name":"Weld up the shell","process":"weld","text":"Robots join the panels into a body with a flat floor, which is built to carry the battery pack and protect it in a crash.","inputs":[]},{"name":"Paint the body","process":"coat","text":"Cars with electric drive go through the same dip, spray and bake routine as any other, since the shell is still steel and aluminum.","inputs":["paint"]},{"name":"Build the drive unit","process":"assemble","text":"An electric motor and its gearing are packed into a compact housing that drives the wheels directly. There is no clutch and no multi-speed gearbox to fit.","inputs":["electric-motor","copper-wire"]},{"name":"Bolt the battery under the floor","process":"assemble","text":"A finished battery pack, made of thousands of cells in cooled and sealed housings, is lifted into the floor and secured. This is the heaviest single part of the car.","inputs":["ev-battery"]},{"name":"Wire the power electronics","process":"assemble","text":"Thick orange cables link battery to drive unit, while smaller wires and control units manage charging, heating and the dashboard.","inputs":["printed-circuit-board","microchip","copper-wire"]},{"name":"Fit glass, seats and wheels","process":"assemble","text":"The interior goes in on the same sort of line as any car, followed by windows and tires.","inputs":["windshield","tire","airbag"]},{"name":"Charge and test drive","process":"inspect","text":"Each car is plugged in, its software is loaded, and it is run on rollers and a test track. Its battery and charging system are checked before it ships.","inputs":[]}],"facts":["Electric car sales reached 21 million in 2025.","China had 44 million electric cars on its roads in 2025, more than half of the world's fleet.","Cars have grown heavier partly because of batteries, safety cages and airbags, and typically weigh between 1 and 3 tonnes."],"where":[],"whereNote":null,"sources":[{"title":"Electric car","url":"https://en.wikipedia.org/wiki/Electric_car"},{"title":"Car","url":"https://en.wikipedia.org/wiki/Car"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ev-battery","name":"Electric car battery","kind":"product","category":"electronics","title":"How electric car batteries are made","url":"https://assemblyline.org/make/ev-battery","stations":6,"upstream":83,"downstream":1,"depth":9,"dek":"Electric cars of 2023 carried anywhere from 21 to 123 kWh of battery, and the average model had 80.","answer":"An electric car battery pack is built from hundreds of lithium-ion cells. Cells are grouped into modules, or sometimes placed straight into the pack, then welded to metal busbars, cooled by aluminum plates and watched by electronics that track every cell. A sealed steel or aluminum housing is bolted under the car.","aka":["EV battery pack","traction battery","electric vehicle battery"],"inputs":["lithium-ion-cell","adhesive","copper","aluminum","printed-circuit-board","steel"],"uses":["electric-car"],"grounds":["water","copper-ore","air","crude-oil","coal","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","iron-ore","natural-gas","sulfur","bauxite","silica-sand","limestone","dolomite","rock-salt","trona","tin-ore","lead-ore","silver-ore","zinc-ore","quartz","timber","corn","sugarcane","sugar-beet"],"upstreamSlugs":["lithium-ion-cell","adhesive","copper","aluminum","printed-circuit-board","steel","lithium-carbonate","cobalt","nickel","manganese","synthetic-graphite","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","copper-ore","oxygen","air","sulfuric-acid","crude-oil","coal","petroleum-coke","alumina","fiberglass","photoresist","solder","pig-iron","magnesium","steel-scrap","lime","argon","lithium-brine","spodumene","soda-ash","cobalt-ore","nickel-ore","manganese-ore","iron-ore","coke","natural-gas","ethylene","propylene","ammonia","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","hydrogen","sulfur","bauxite","silica-sand","limestone","phenolic-resin","tin","lead","silver","dolomite","silicon","propane","rock-salt","carbon-dioxide","trona","naphtha","benzene","formaldehyde","tin-ore","lead-ore","zinc","silver-ore","zinc-ore","quartz","charcoal","timber","corn","yeast","toluene","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["electric-car"],"steps":[{"name":"Sort matched cells","process":"inspect","text":"Cells from one batch still differ slightly, so each is tested for voltage, capacity and internal resistance. Only closely matched cells go on together, and every later stage inherits what this one leaves behind.","inputs":["lithium-ion-cell"]},{"name":"Stack and compress modules","process":"assemble","text":"End plates squeeze the stack with a controlled force, leaving room for the swelling cells do over a charge cycle. A camera checks terminal alignment. Newer cell-to-pack designs skip modules and go straight into the pack structure.","inputs":["adhesive"]},{"name":"Weld the busbars","process":"weld","text":"Laser, ultrasonic or resistance welding joins cells into an electrically connected string. Technicians pull-test the joints, because one that looks fine can still carry too much resistance.","inputs":["copper","aluminum"]},{"name":"Fit cooling and electronics","process":"assemble","text":"Liquid cooling plates go between the cells, along with high-voltage contactors, fuses and the management system that watches every cell's voltage and temperature.","inputs":["printed-circuit-board","aluminum"]},{"name":"Seal the housing","process":"assemble","text":"Crash structures and seals against water and dust close up the enclosure, a case something like a sealed steel suitcase.","inputs":["steel"]},{"name":"Test the finished pack","process":"inspect","text":"Finished packs face leak and insulation tests, charge and discharge validation, vibration rigs and thermal cycling before being bolted under a car.","inputs":[]}],"facts":["Three cell types dominate electric vehicles: cylindrical, prismatic pouch and prismatic can.","Traction batteries hold far more energy than the starting batteries of combustion cars."],"where":[],"whereNote":null,"sources":[{"title":"MeraEV: How an EV battery is made","url":"https://www.meraev.com/blog/how-an-ev-battery-is-made-the-lithium-ion-manufacturing-process-from-powder-to-pack"},{"title":"Sunlith Energy: Battery pack assembly process","url":"https://sunlithenergy.com/?p=5887"},{"title":"Electric vehicle battery","url":"https://en.wikipedia.org/wiki/Electric_vehicle_battery"},{"title":"Lithium-ion battery","url":"https://en.wikipedia.org/wiki/Lithium-ion_battery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"electric-guitar","name":"Electric guitar","kind":"product","category":"play","title":"How electric guitars are made","url":"https://assemblyline.org/make/electric-guitar","stations":8,"upstream":60,"downstream":0,"depth":6,"dek":"An electric guitar makes almost no sound by itself. Its pickups turn string vibration into current.","answer":"An electric guitar is a solid body of hardwood with a bolted or glued neck and magnetic pickups beneath the strings. Bodies are cut, routed and sanded, necks are carved and fretted, and the pieces are painted. Pickups are wound from fine copper wire, then wired to knobs and a jack.","aka":["solid-body guitar","electric"],"inputs":["lumber","timber","copper-wire","lacquer","solder","brass","steel-wire"],"uses":[],"grounds":["timber","copper-ore","water","air","corn","sugarcane","tin-ore","lead-ore","silver-ore","zinc-ore","crude-oil","coal","sulfur","natural-gas","limestone","bauxite","iron-ore","dolomite","manganese-ore","sugar-beet","rock-salt","quartz"],"upstreamSlugs":["lumber","timber","copper-wire","lacquer","solder","brass","steel-wire","copper","ethanol","acrylic","tin","lead","silver","zinc","aluminum","steel","copper-ore","water","oxygen","air","sulfuric-acid","corn","sugarcane","yeast","ethylene","propylene","ammonia","methanol","tin-ore","coke","lead-ore","silver-ore","zinc-ore","lime","crude-oil","coal","petroleum-coke","alumina","pig-iron","magnesium","steel-scrap","manganese","argon","sulfur","molasses","naphtha","natural-gas","limestone","bauxite","caustic-soda","iron-ore","dolomite","silicon","propane","manganese-ore","sugar-beet","hydrogen","rock-salt","quartz","charcoal"],"downstreamSlugs":[],"steps":[{"name":"Cut the body blank","process":"cut","text":"Planks of hardwood are glued together and cut into the outline of the body. A solid body does not resonate, so the sound comes from the string alone.","inputs":["lumber"]},{"name":"Rout the cavities","process":"machine","text":"Computer-controlled routers carve pockets for pickups and wiring, and a channel for the neck.","inputs":[]},{"name":"Carve the neck","process":"machine","text":"A neck is cut from a long board, thinned to a comfortable profile, and given a fingerboard. Frets are pressed into slots along it.","inputs":["timber"]},{"name":"Wind the pickups","process":"assemble","text":"A pickup is a magnet wrapped in a coil of fine wire. A moving steel string disturbs the magnetic field and induces a small electric signal.","inputs":["copper-wire"]},{"name":"Spray and polish","process":"coat","text":"The body and neck are sprayed with color and a clear lacquer coat, left to cure and buffed to a gloss.","inputs":["lacquer"]},{"name":"Fit the hardware","process":"assemble","text":"A bridge, tuning machines, knobs, switches and an output jack are mounted. Pickups are wired to the controls.","inputs":["solder","brass"]},{"name":"String and set up","process":"assemble","text":"Steel strings are fitted and tuned. The maker adjusts the neck, string height and intonation so each fret plays in tune.","inputs":["steel-wire"]},{"name":"Play-test it","process":"inspect","text":"Each guitar is plugged into an amplifier and checked for buzz, dead spots and noise.","inputs":[]}],"facts":["The Fender Esquire and Broadcaster, later renamed the Telecaster, first made in 1950, were the first mass-produced solid-body guitars.","George Beauchamp and Adolph Rickenbacker invented the electromagnetic pickup.","In 1940 Les Paul built a \"log guitar\" from a wood post with a neck attached, an experiment that later inspired the 1952 Gibson Les Paul."],"where":[],"whereNote":null,"sources":[{"title":"Electric guitar","url":"https://en.wikipedia.org/wiki/Electric_guitar"},{"title":"Acoustic guitar","url":"https://en.wikipedia.org/wiki/Acoustic_guitar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"electric-kettle","name":"Electric kettle","kind":"product","category":"machines","title":"How electric kettles are made","url":"https://assemblyline.org/make/electric-kettle","stations":10,"upstream":95,"downstream":0,"depth":11,"dek":"Most of an electric kettle's electrics arrive at the factory already built, in one bundled set per kettle.","answer":"Two steel stampings nest like bowls to form the base of a plastic-bodied electric kettle, while polypropylene pellets are injection molded into the upper housing and handle. Electrical parts arrive from subcontractors as one bundled set per kettle, including a fully enclosed 2 to 3 kilowatt element. Workers fit them, seal base to body, and switch each kettle on before boxing.","aka":["kettle","electric jug","hot water jug"],"inputs":["stainless-steel","paint","polypropylene","copper-wire","rubber","nichrome","plastic-bag","cardboard-box"],"uses":[],"grounds":["water","natural-latex","sulfur","chromite","limestone","air","nickel-ore","titanium-ore","iron-ore","crude-oil","copper-ore","natural-gas","coal","rock-salt","trona","soybeans","rapeseed","clay","corn","sugarcane","timber","bauxite","tin-ore","dolomite","manganese-ore","sugar-beet","quartz"],"upstreamSlugs":["stainless-steel","paint","polypropylene","copper-wire","rubber","nichrome","plastic-bag","cardboard-box","steel-scrap","chromium","nickel","oxygen","argon","water","titanium-dioxide","pigment","acrylic","tin-can","propylene","copper","natural-latex","synthetic-rubber","carbon-black","sulfur","polyethylene","ink","cardboard","adhesive","propane","chromite","coke","soda-ash","limestone","air","aluminum","nickel-ore","sulfuric-acid","titanium-ore","chlorine","iron-ore","ammonia","methanol","tinplate","lacquer","naphtha","crude-oil","copper-ore","benzene","ethylene","styrene","vegetable-oil","phenolic-resin","ethanol","wood-pulp","epoxy","polyurethane","paraffin-wax","natural-gas","coal","rock-salt","carbon-dioxide","lime","trona","petroleum-coke","alumina","steel","tin","hydrogen","toluene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","corn","sugarcane","yeast","timber","caustic-soda","hydrogen-peroxide","acetone","nitric-acid","bauxite","pig-iron","magnesium","manganese","tin-ore","molasses","dolomite","silicon","manganese-ore","sugar-beet","quartz","charcoal"],"downstreamSlugs":[],"steps":[{"name":"Punch the base shell","process":"stamp","text":"Sheet steel, checked for thickness on arrival, goes under a punch press. A hydraulic punch drops and draws out a hollow shell that becomes the base. All-metal models use high-grade steel for the whole housing.","inputs":["stainless-steel"]},{"name":"Press the element seat","process":"stamp","text":"A second sheet is pressed in a die that forms a seat for the element. This stamping sits inside the first, like one bowl in another.","inputs":["stainless-steel"]},{"name":"Coat the stampings","process":"coat","text":"Hangers carry both pieces along a conveyor. The base takes a small charge that attracts a fine paint mist in a booth, matched to the plastic color. The water side of the other piece gets a treatment that makes mineral deposits easier to remove.","inputs":["paint"]},{"name":"Mold the upper housing","process":"mold","text":"Polypropylene pellets drop by gravity from a hopper and melt into a liquid. High pressure forces it into a two-part steel die whose halves shape the outside, the inside and a solid handle. The hot housing is ejected and left to cool.","inputs":["polypropylene"]},{"name":"Weld the two stampings","process":"weld","text":"The painted and treated stampings are welded together into one base, which then moves onto a conveyor belt.","inputs":[]},{"name":"Fit the electrical set","process":"assemble","text":"A worker unwraps the set and seats the connector between element and cord in its opening in the base. On automatic kettles a bimetallic strip, warmed by steam through a pipe, trips the current at the boil. Rubber feet go on here too.","inputs":["copper-wire","rubber","nichrome"]},{"name":"Seal base to body","process":"assemble","text":"The metal base, electrics in place, is sealed to the plastic housing to complete the body.","inputs":[]},{"name":"Press on spout cover","process":"assemble","text":"A flip-up metal cover is pressed by hand onto the wide plastic spout, which also serves as the filling hole. Other models get a metal lid with a small molded handle.","inputs":[]},{"name":"Plug in each one","process":"inspect","text":"Materials and parts have been inspected at every step since receiving. As the last check, each kettle is plugged in and operated.","inputs":[]},{"name":"Bag and box","process":"package","text":"Each kettle goes in a plastic bag with its instructions, then a box, and the boxes fill shipping cartons.","inputs":["plastic-bag","cardboard-box"]}],"facts":["The heating element in a modern kettle draws up to 13 amps.","By 1890, General Electric was already selling electric kettles in London.","Russell Hobbs introduced the first fully automatic kettle, the stainless steel K1."],"where":[],"whereNote":null,"sources":[{"title":"Electric Tea Kettle, How Products Are Made","url":"https://encyclopedia.com/manufacturing/news-wires-white-papers-and-books/electric-tea-kettle"},{"title":"Electric kettle","url":"https://en.wikipedia.org/wiki/Electric_kettle"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"electric-motor","name":"Electric motor","kind":"product","category":"machines","title":"How electric motors are made","url":"https://assemblyline.org/make/electric-motor","stations":6,"upstream":44,"downstream":17,"depth":7,"dek":"The stator is a stack of thin steel sheets, insulated from each other so currents cannot swirl inside the core.","answer":"An electric motor has a fixed stator and a spinning rotor. Thin sheets of electrical steel are stamped out and stacked to make the stator core, which is wound with copper wire. The windings are soaked in varnish under vacuum. A rotor with its shaft is fitted on bearings, and the housing is closed.","aka":["motor","AC motor","induction motor","brushless motor"],"inputs":["sheet-steel","copper-wire","epoxy","ball-bearing","steel"],"uses":["refrigerator","microwave-oven","washing-machine","vacuum-cleaner","drone","electric-car","locomotive","elevator","blender","dishwasher","air-conditioner","treadmill","subway-train","game-console","inkjet-printer","graphics-card"],"grounds":["zinc-ore","air","copper-ore","water","crude-oil","rock-salt","iron-ore","limestone","dolomite","manganese-ore","natural-gas","sulfur","coal","quartz","timber"],"upstreamSlugs":["sheet-steel","copper-wire","epoxy","ball-bearing","steel","zinc","copper","phenol","propylene","acetone","chlorine","caustic-soda","steel-wire","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","copper-ore","water","benzene","naphtha","crude-oil","rock-salt","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","sulfur","hydrogen","toluene","coal","quartz","charcoal","timber"],"downstreamSlugs":["refrigerator","microwave-oven","washing-machine","vacuum-cleaner","drone","electric-car","locomotive","elevator","blender","dishwasher","air-conditioner","treadmill","subway-train","game-console","inkjet-printer","graphics-card","skyscraper"],"steps":[{"name":"Stamp the laminations","process":"stamp","text":"Thin sheets of electrical steel are punched into ring and disk shapes, each insulated from the next. A solid core would allow wasteful circulating currents, so the core is made of thin plates.","inputs":["sheet-steel"]},{"name":"Stack the stator core","process":"assemble","text":"The laminations are stacked and bonded into a tube with slots on the inside.","inputs":[]},{"name":"Wind in the copper","process":"assemble","text":"Coils of copper wire are wound and pushed into the slots. Current in these windings creates the magnetic field that drives the rotor.","inputs":["copper-wire"]},{"name":"Varnish under vacuum","process":"coat","text":"Mains-powered AC motors have their windings impregnated with varnish in a vacuum. This holds the wires still so they do not rub through their insulation. Some motors are packed in plastic resin instead.","inputs":["epoxy"]},{"name":"Fit the rotor and bearings","process":"assemble","text":"The rotor and shaft are set inside the stator on bearings, with end plates holding everything in line.","inputs":["ball-bearing","steel"]},{"name":"Spin test","process":"inspect","text":"Each motor is run to check speed, current and vibration.","inputs":[]}],"facts":["An electric generator is mechanically identical to an electric motor but works in reverse.","Resin-packed motors are used in deep-well submersible pumps, washing machines and air conditioners.","Most electric motors work through the force between a magnetic field and the current in a wire winding."],"where":[],"whereNote":null,"sources":[{"title":"Electric motor","url":"https://en.wikipedia.org/wiki/Electric_motor"},{"title":"Transformer","url":"https://en.wikipedia.org/wiki/Transformer"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"electric-toothbrush","name":"Electric toothbrush","kind":"product","category":"electronics","title":"How electric toothbrushes are made","url":"https://assemblyline.org/make/electric-toothbrush","stations":6,"upstream":101,"downstream":0,"depth":9,"dek":"Electric toothbrushes were first built for people with limited hand control and for patients with braces.","answer":"An electric toothbrush has a small motor that makes the brush head oscillate or vibrate, a rechargeable battery and a sealed plastic handle. The motor and a small circuit board are fitted into a molded case. Nylon bristles are tufted into the replaceable head, and the handle is sealed against water.","aka":["powered toothbrush","sonic toothbrush","oscillating toothbrush"],"inputs":["abs-plastic","rubber","copper-wire","neodymium-magnet","printed-circuit-board","microchip","solder","nylon","steel","lithium-ion-cell","silicone"],"uses":[],"grounds":["air","natural-latex","sulfur","rare-earth-ore","water","silica-sand","crude-oil","natural-gas","iron-ore","copper-ore","nickel-ore","zinc-ore","limestone","quartz","tin-ore","coal","gold-ore","lead-ore","silver-ore","dolomite","manganese-ore","lithium-brine","spodumene","cobalt-ore","timber","titanium-ore","rock-salt","trona","bauxite","corn","sugarcane","sugar-beet"],"upstreamSlugs":["abs-plastic","rubber","copper-wire","neodymium-magnet","printed-circuit-board","microchip","solder","nylon","steel","lithium-ion-cell","silicone","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","natural-latex","synthetic-rubber","carbon-black","sulfur","copper","rare-earth-ore","nickel","zinc","fiberglass","epoxy","photoresist","silicon-wafer","oxygen","tin","aluminum","gold","lead","silver","nitric-acid","pig-iron","magnesium","steel-scrap","lime","manganese","argon","lithium-carbonate","cobalt","synthetic-graphite","polyethylene","silicon","methanol","hydrochloric-acid","water","silica-sand","crude-oil","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","copper-ore","sulfuric-acid","nickel-ore","zinc-ore","limestone","soda-ash","phenol","acetone","chlorine","caustic-soda","phenolic-resin","polysilicon","quartz","tin-ore","coke","coal","petroleum-coke","alumina","gold-ore","lead-ore","silver-ore","dolomite","propane","manganese-ore","lithium-brine","spodumene","cobalt-ore","charcoal","timber","titanium-ore","rock-salt","carbon-dioxide","trona","formaldehyde","trichlorosilane","nitrogen","bauxite","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the handle","process":"mold","text":"Plastic is injected into steel molds to form the two halves of the handle. A soft grip of rubber may be molded over the plastic.","inputs":["abs-plastic","rubber"]},{"name":"Wind the motor","process":"assemble","text":"Fine copper wire is wound into coils for a small motor. In a sonic brush the motor drives a rapid back-and-forth motion, and in an ultrasonic brush a piezoelectric crystal vibrates the head.","inputs":["copper-wire","neodymium-magnet"]},{"name":"Build the electronics","process":"assemble","text":"A small circuit board with a chip and a charging coil is soldered. Most modern brushes charge by induction, without any exposed electrical contacts.","inputs":["printed-circuit-board","microchip","solder"]},{"name":"Tuft the bristles","process":"assemble","text":"Nylon bristles are inserted into the head and fastened. A computer-guided machine then slices them to length and shape, and the tips are rounded so they will not damage the gums.","inputs":["nylon","steel"]},{"name":"Fit the battery and seal","process":"weld","text":"The rechargeable battery, motor and board are set into the handle, and a gasket seals the shaft. The halves are welded together by ultrasound so water cannot get in.","inputs":["lithium-ion-cell","silicone"]},{"name":"Test the motion","process":"inspect","text":"Each brush is tested for humidity, waterproofing, stability and sound level, with a rig checking its stroke and charging. One maker says its brush has more than 500 individual elements.","inputs":[]}],"facts":["Electric toothbrushes are grouped by speed as power, sonic or ultrasonic, depending on whether they move below, within or above the audible range.","Some brushes are assembled in clean rooms, to keep dust and germs out of a product that goes in the mouth."],"where":[],"whereNote":null,"sources":[{"title":"Electric toothbrush","url":"https://en.wikipedia.org/wiki/Electric_toothbrush"},{"title":"How electric toothbrushes are manufactured (Relish)","url":"https://relish-tech.com/?p=3996"},{"title":"Electric toothbrush: how it's made (Ordo)","url":"https://ordolife.com/blogs/ordo-life/electric-toothbrush-how-its-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"transformer","name":"Electrical transformer","kind":"product","category":"machines","title":"How electrical transformers are made","url":"https://assemblyline.org/make/transformer","stations":6,"upstream":31,"downstream":2,"depth":6,"dek":"Two coils share one iron core, and the ratio of their turns sets the voltage.","answer":"A transformer is two or more wire coils wound around a shared magnetic core. That core is a stack of thin steel plates insulated from each other, which cuts energy lost to eddy currents. Copper wire forms the coils, which are insulated. Larger units are dried and filled with oil.","aka":["power transformer","mains transformer","step-down transformer"],"inputs":["sheet-steel","copper-wire","steel"],"uses":["microwave-oven","phone-charger"],"grounds":["zinc-ore","air","copper-ore","water","iron-ore","limestone","dolomite","manganese-ore","natural-gas","sulfur","coal","quartz","timber","crude-oil"],"upstreamSlugs":["sheet-steel","copper-wire","steel","zinc","copper","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","copper-ore","water","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","sulfur","coal","quartz","charcoal","timber","crude-oil"],"downstreamSlugs":["microwave-oven","phone-charger"],"steps":[{"name":"Cut the core plates","process":"cut","text":"Thin plates of silicon steel are cut to shape. Good-quality silicon steel in the core lowers energy losses.","inputs":["sheet-steel"]},{"name":"Stack the laminated core","process":"assemble","text":"Plates are stacked and insulated from each other. Stacked laminations cut eddy currents compared with a solid block.","inputs":[]},{"name":"Wind the coils","process":"assemble","text":"Copper wire is wound on forms. The primary and secondary windings must have the number of turns that sets the voltage ratio.","inputs":["copper-wire"]},{"name":"Insulate and fit the coils","process":"assemble","text":"Insulation is wrapped around the windings, and the coils are slipped over the core legs.","inputs":[]},{"name":"Dry and seal the unit","process":"dry","text":"The assembly is dried to remove moisture, then encased or placed in a tank.","inputs":["steel"]},{"name":"Test the ratio","process":"inspect","text":"Voltage ratio, losses and insulation are measured before shipment.","inputs":[]}],"facts":["Faraday's law of induction, discovered in 1831, explains why a changing current in one coil induces a voltage in another.","Transformers move energy between circuits with no metal connection between them.","Better silicon steel or amorphous steel cores lower losses but raise the initial cost."],"where":[],"whereNote":null,"sources":[{"title":"Transformer","url":"https://en.wikipedia.org/wiki/Transformer"},{"title":"Electric motor","url":"https://en.wikipedia.org/wiki/Electric_motor"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"elevator","name":"Elevator","kind":"product","category":"machines","title":"How elevators are made","url":"https://assemblyline.org/make/elevator","stations":8,"upstream":78,"downstream":1,"depth":9,"dek":"A traction elevator is balanced by a counterweight, so the motor lifts only the difference between the car and its load.","answer":"An elevator is a car hung on steel ropes that loop over a drive sheave and down to a counterweight. Factories roll guide rails, weave the ropes, build the cab, and assemble the motor, brake and controller. The parts are then installed in a shaft, adjusted and tested, including the safety brakes.","aka":["lift","passenger elevator"],"inputs":["steel","wire-rope","sheet-steel","stainless-steel","electric-motor","ball-bearing","printed-circuit-board","copper-wire"],"uses":["skyscraper"],"grounds":["iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","zinc-ore","chromite","nickel-ore","copper-ore","silica-sand","coal","quartz","timber","crude-oil","sulfur","rock-salt","trona","tin-ore","lead-ore","silver-ore","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["steel","wire-rope","sheet-steel","stainless-steel","electric-motor","ball-bearing","printed-circuit-board","copper-wire","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","steel-wire","zinc","chromium","nickel","epoxy","copper","fiberglass","photoresist","solder","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","zinc-ore","chromite","soda-ash","aluminum","nickel-ore","phenol","propylene","acetone","chlorine","caustic-soda","copper-ore","silica-sand","phenolic-resin","tin","lead","silver","coal","quartz","charcoal","timber","crude-oil","sulfur","rock-salt","ammonia","carbon-dioxide","trona","petroleum-coke","alumina","benzene","naphtha","formaldehyde","tin-ore","lead-ore","silver-ore","corn","yeast","bauxite","hydrogen","toluene","methanol","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["skyscraper"],"steps":[{"name":"Roll the guide rails","process":"roll","text":"Steel rails are rolled and machined straight. They run the height of the shaft and keep the car and counterweight from swaying.","inputs":["steel"]},{"name":"Twist the hoist ropes","process":"assemble","text":"Strands of steel wire are twisted into rope that rolls over a grooved pulley, called a sheave. The ropes carry the weight of the car.","inputs":["wire-rope"]},{"name":"Build the cab","process":"assemble","text":"Panels of sheet steel, stainless steel or glass are fitted on a steel frame, with floor, ceiling, handrail and lights.","inputs":["sheet-steel","stainless-steel"]},{"name":"Assemble the drive machine","process":"assemble","text":"An electric motor, brake and sheave are mounted together. Gearless machines connect the sheave straight to the motor, and the best of them reach speeds of up to 20 m/s.","inputs":["electric-motor","ball-bearing"]},{"name":"Load the counterweight","process":"assemble","text":"A steel frame is filled with heavy blocks, sized to balance the car plus about half a full load.","inputs":["steel"]},{"name":"Wire the controller and doors","process":"assemble","text":"A controller reads the call buttons and floor sensors and commands the motor. Door operators and safety switches are connected.","inputs":["printed-circuit-board","copper-wire"]},{"name":"Install it in the shaft","process":"assemble","text":"Technicians fix the rails in the building, hang the car and counterweight on their ropes, and set the machine in place.","inputs":[]},{"name":"Test the safeties","process":"inspect","text":"Inspectors check that the brake holds on loss of power and that the emergency gear grips the rails. A spring-applied brake engages on a power failure and stops the car from falling.","inputs":[]}],"facts":["Frank Sprague improved the electric elevator with floor control, automatic operation and acceleration control.","Gearless traction machines were introduced in the 1930s, and AC permanent-magnet machines with inverters appeared in 1995.","Many elevators in a bank are run so their cars move in opposite directions, each acting as the other's counterweight."],"where":[],"whereNote":null,"sources":[{"title":"Elevator","url":"https://en.wikipedia.org/wiki/Elevator"},{"title":"Locomotive","url":"https://en.wikipedia.org/wiki/Locomotive"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"energy-drink","name":"Energy drink","kind":"product","category":"drink","title":"How energy drinks are made","url":"https://assemblyline.org/make/energy-drink","stations":7,"upstream":63,"downstream":0,"depth":9,"dek":"Industrial caffeine is built from urea and chloroacetic acid, and Red Bull says it is identical to natural caffeine.","answer":"An energy drink is a carbonated soft drink with added caffeine. A factory blends sweetener, acid, flavor, color, caffeine, vitamins and preservatives into a concentrated mix, screens it for foreign material, and adds chilled water in a carbonation tank. Rinsed cans are filled and sealed. A serving carries between 50 and 505 milligrams of caffeine.","aka":["caffeinated drink","stimulant drink"],"inputs":["sugar","water","caffeine","carbon-dioxide","aluminum-can","cardboard"],"uses":[],"grounds":["water","sugarcane","sugar-beet","coffee-cherries","natural-gas","corn","limestone","crude-oil","coal","timber","bauxite","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","rock-salt"],"upstreamSlugs":["sugar","water","caffeine","carbon-dioxide","aluminum-can","cardboard","sugarcane","sugar-beet","lime","coffee-cherries","natural-gas","corn","yeast","limestone","aluminum","ink","epoxy","wood-pulp","adhesive","molasses","crude-oil","coal","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","phenol","propylene","acetone","chlorine","caustic-soda","timber","oxygen","hydrogen-peroxide","polyethylene","acrylic","polyurethane","paraffin-wax","bauxite","soybeans","rapeseed","hexane","clay","formaldehyde","air","titanium-ore","coke","sulfuric-acid","iron-ore","sulfur","ethylene","benzene","naphtha","rock-salt","hydrogen","ammonia","methanol","nitric-acid","toluene"],"downstreamSlugs":[],"steps":[{"name":"Make the caffeine","process":"react","text":"Caffeine can come from plants or from a chemical plant, where it is synthesized from urea and chloroacetic acid. The processes were mostly patented between the 1940s and the 1960s.","inputs":[]},{"name":"Blend the ingredients","process":"mix","text":"Citric acid, flavors, colors, caffeine, preservatives, vitamins and sweeteners are dry-blended or stirred with water in a mixing kettle. Many of them arrive ready to eat, so this stage has no cooking step.","inputs":["sugar","water","caffeine"]},{"name":"Run it through screens","process":"separate","text":"The mix passes screens that catch foreign material from the ingredients or from worn equipment. Operators check them at intervals, because what they catch shows whether something upstream has failed.","inputs":[]},{"name":"Carbonate with chilled water","process":"react","text":"A chilled water tank brings the water to temperature. In the carbonation tank the mix meets that water and the carbon dioxide dissolves into the liquid.","inputs":["water","carbon-dioxide"]},{"name":"Rinse the empty cans","process":"wash","text":"A twist and rinse system turns the cans and rinses them to clear out dust and foreign material just before filling.","inputs":["aluminum-can"]},{"name":"Fill and seal","process":"fill","text":"The cans are filled and sealed, then labeled if the can maker has not already printed them.","inputs":[]},{"name":"Tray and ship","process":"package","text":"Cans are grouped into trays and cartons for shipping.","inputs":["cardboard"]}],"facts":["An 8.4 ounce can of Red Bull has 80 milligrams of caffeine, about the same as a cup of home-brewed coffee, while some energy drink servings reach 505 milligrams.","Studies attribute most of the drinks' effect on attention and reaction speed to caffeine, with little evidence that the other added ingredients do anything.","Low pH and carbonation both limit bacteria in a canned energy drink, so they serve as food-safety controls."],"where":[],"whereNote":null,"sources":[{"title":"Energy drink","url":"https://en.wikipedia.org/wiki/Energy_drink"},{"title":"Caffeine","url":"https://en.wikipedia.org/wiki/Caffeine"},{"title":"How to make a safe ready-to-drink energy drink (SDSU Extension)","url":"https://extension.sdstate.edu/how-make-safe-ready-drink-energy-drink"},{"title":"Red Bull ingredients","url":"https://www.redbull.com/us-en/energydrink/red-bull-energy-drink-ingredients-list"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"envelope","name":"Envelope","kind":"product","category":"wood-paper","title":"How envelopes are made","url":"https://assemblyline.org/make/envelope","stations":6,"upstream":57,"downstream":0,"depth":10,"dek":"Every envelope is a flat sheet that was folded around a rectangle, and cutting diamonds wastes less paper.","answer":"An envelope is a flat paper blank cut to a diamond, cross or kite shape so that folding its sides around a central rectangle forms a pocket. Machines cut the blanks from a reel, fold the flaps, glue the side seams and coat the sealing flap with gum, then count and box the finished envelopes.","aka":["mailing envelope","window envelope"],"inputs":["paper","adhesive","cardboard-box"],"uses":[],"grounds":["water","kaolin","limestone","timber","crude-oil","rock-salt","air","natural-gas","sulfur","soybeans","rapeseed","clay","titanium-ore","iron-ore","corn","sugarcane","coal","sugar-beet"],"upstreamSlugs":["paper","adhesive","cardboard-box","wood-pulp","water","kaolin","limestone","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","cardboard","ink","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","hydrogen","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","rock-salt","air","naphtha","natural-gas","sulfur","benzene","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","coke","iron-ore","corn","sugarcane","yeast","toluene","coal","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the flat blanks","process":"cut","text":"Paper from a reel is guillotined into sheets, and dies cut a blank out of each. Tessellating the shapes across a big sheet, a trick first patented in 1840, leaves almost no scrap.","inputs":["paper"]},{"name":"Punch the window","process":"stamp","text":"For window envelopes, a hole is cut in the front so the address on the letter inside shows through. The hole is covered with clear plastic or glassine.","inputs":[]},{"name":"Fold the flaps over","process":"assemble","text":"Folding machines have taken over from hand folding since the early twentieth century. They crease each blank and lay the side and bottom flaps over the middle rectangle.","inputs":[]},{"name":"Glue the seams","process":"laminate","text":"A thin line of glue holds the overlapping flaps together so the envelope becomes a closed pocket open only at the top.","inputs":["adhesive"]},{"name":"Gum the sealing flap","process":"coat","text":"A stripe of gummed adhesive is applied along the edge of the top flap. The sealing adhesive dries until the sender moistens it or presses it down.","inputs":["adhesive"]},{"name":"Count and box","process":"package","text":"Finished envelopes are stacked, counted and packed flat in boxes for shipping.","inputs":["cardboard-box"]}],"facts":["Until 1840, every envelope in the world was cut and folded by hand.","The British mass-production machine of 1845 made envelopes by creasing pre-cut diamond-shaped blanks, which were still folded by hand.","The plastic window in a window envelope can cause problems in paper recycling."],"where":[],"whereNote":null,"sources":[{"title":"Envelope","url":"https://en.wikipedia.org/wiki/Envelope"},{"title":"Papermaking","url":"https://en.wikipedia.org/wiki/Papermaking"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"epoxy","name":"Epoxy","kind":"material","category":"plastics","title":"How epoxy is made","url":"https://assemblyline.org/make/epoxy","stations":6,"upstream":17,"downstream":182,"depth":6,"dek":"Epoxy is sold as two liquids that are harmless apart, and it only turns solid when you mix them.","answer":"Epoxy is sold in two parts. The resin is made by reacting bisphenol A with epichlorohydrin and caustic soda, then washing out the salt. The hardener, usually an amine, is made separately. Nothing happens until the two are mixed at the point of use, and then the molecules cross-link into a thermoset solid.","aka":["epoxy resin","polyepoxide"],"inputs":["phenol","propylene","acetone","chlorine","caustic-soda"],"uses":["thermometer","adhesive","printed-circuit-board","wind-turbine","electric-motor","rebar","aluminum-can","airplane","surfboard","ski","snowboard","tennis-racket","fishing-rod","prosthetic-leg","loudspeaker","umbrella"],"grounds":["air","crude-oil","rock-salt","water","sulfur","natural-gas","coal"],"upstreamSlugs":["phenol","propylene","acetone","chlorine","caustic-soda","benzene","air","naphtha","crude-oil","rock-salt","water","sulfuric-acid","hydrogen","toluene","sulfur","natural-gas","coal"],"downstreamSlugs":["thermometer","adhesive","printed-circuit-board","wind-turbine","electric-motor","rebar","aluminum-can","airplane","surfboard","ski","snowboard","tennis-racket","fishing-rod","prosthetic-leg","loudspeaker","umbrella","adhesive-bandage","credit-card","duct-tape","led-bulb","ev-battery","pencil","nail","insulation","popcorn","windshield","skateboard","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","pencil-eraser","clear-tape","staple","sofa","ice-skates","golf-club","volleyball","cricket-bat","dartboard","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","globe","snow-globe","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","brake-pad","sailboat","dress-shirt","suit","raincoat","handbag","suitcase","wallet","flip-flops","hiking-boots","high-heels","smartwatch","wireless-earbuds","microphone","camera-lens","e-reader","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","sneaker","leather-shoe","baseball-cap","carpet","mattress","diaper","hearing-aid","pacemaker","smartphone","laptop","television","hard-drive","solid-state-drive","computer-keyboard","computer-mouse","microwave-oven","washing-machine","drone","satellite","car","electric-car","airbag","rocket","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","smoke-detector","phone-charger","digital-camera","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","refrigerator","vacuum-cleaner","dishwasher","air-conditioner","subway-train","concrete","skyscraper","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","aluminum-window-frame","shipping-container","toothbrush","fireworks","plastic-wrap","trading-cards","cake-mix","hair-dye","tampon","soap","toothpaste","detergent","plastic-bag","nitrile-glove","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","cough-syrup","wheelbarrow","light-switch","facial-tissue","aa-battery","candy-cane","syringe"],"steps":[{"name":"Make bisphenol A","process":"react","text":"Phenol and acetone, both derived from propylene and benzene, are condensed into bisphenol A. It is the backbone of most epoxy resin.","inputs":["phenol","propylene","acetone"]},{"name":"Make epichlorohydrin","process":"react","text":"Propylene is reacted with chlorine to make the reactive three-carbon compound epichlorohydrin. It supplies the epoxide groups that give the resin its name.","inputs":["chlorine","propylene"]},{"name":"React the two with lye","process":"react","text":"Bisphenol A meets an excess of epichlorohydrin and sodium hydroxide in a reactor. Salt forms as a byproduct, and a thick, honey-like liquid resin is left.","inputs":["caustic-soda"]},{"name":"Wash and strip the resin","process":"wash","text":"The salt is washed out with water and the extra epichlorohydrin is distilled off and reused. The finished resin is a clear liquid.","inputs":[]},{"name":"Package resin and hardener","process":"package","text":"Resin goes into one container and a hardener, typically a polyfunctional amine, into another. Splitting them lets the product sit in a store for months.","inputs":[]},{"name":"Mix and cure on site","process":"dry","text":"When the customer combines the parts, the hardener links the resin molecules into a rigid three-dimensional network. The result is a thermosetting plastic that heat will not melt.","inputs":[]}],"facts":["Paul Schlack of Germany patented the condensation of epoxides and amines in 1934.","Claims of discovery of bisphenol-A epoxy resins include Pierre Castan in 1943, and Ciba licensed his work.","Between 25 and 30% of all bisphenol A goes into making epoxy and vinyl ester resins."],"where":[],"whereNote":null,"sources":[{"title":"Epoxy","url":"https://en.wikipedia.org/wiki/Epoxy"},{"title":"Bisphenol A","url":"https://en.wikipedia.org/wiki/Bisphenol_A"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pencil-eraser","name":"Eraser","kind":"product","category":"plastics","title":"How pencil erasers are made","url":"https://assemblyline.org/make/pencil-eraser","stations":6,"upstream":57,"downstream":0,"depth":8,"dek":"A pencil eraser is usually synthetic rubber loaded with pumice, which does the actual scrubbing.","answer":"Rubber, natural or synthetic, is blended with pigment, vegetable oil, pumice and sulfur. The mix is pushed through a die as a long rod, heated so the sulfur cross-links the rubber, and cut into plugs. The plugs are pressed into metal ferrules at the pencil factory and fixed with glue or metal prongs.","aka":["rubber","pencil rubber","cap eraser"],"inputs":["synthetic-rubber","natural-latex","sulfur","vegetable-oil","titanium-dioxide","pigment","aluminum","brass","adhesive"],"uses":[],"grounds":["natural-latex","sulfur","water","soybeans","rapeseed","clay","titanium-ore","iron-ore","crude-oil","coal","natural-gas","rock-salt","air","bauxite","copper-ore","zinc-ore","lead-ore","tin-ore","limestone"],"upstreamSlugs":["synthetic-rubber","natural-latex","sulfur","vegetable-oil","titanium-dioxide","pigment","aluminum","brass","adhesive","naphtha","benzene","ethylene","styrene","water","soybeans","rapeseed","hexane","clay","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","carbon-black","crude-oil","coal","petroleum-coke","alumina","copper","zinc","lead","tin","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","hydrogen","toluene","natural-gas","rock-salt","air","bauxite","caustic-soda","lime","copper-ore","zinc-ore","lead-ore","tin-ore","propylene","ammonia","methanol","phenol","acetone","nitric-acid","limestone"],"downstreamSlugs":[],"steps":[{"name":"Blend rubber and fillers","process":"mix","text":"Rubber is mixed with pigments, vegetable oil, pumice and sulfur. Oil softens the mix, and pumice gives it a gentle grit that lifts graphite off paper.","inputs":["synthetic-rubber","natural-latex","sulfur","vegetable-oil","titanium-dioxide","pigment"]},{"name":"Extrude the plug rod","process":"extrude","text":"The warm, still uncured mixture is pushed through a round die in a continuous rod. Flat erasers are instead injected into molds.","inputs":[]},{"name":"Heat to vulcanize","process":"heat-treat","text":"Heat makes the sulfur cross-link the rubber molecules, which turns a sticky gum into a durable rubber. Charles Goodyear discovered the process in 1839 and patented it in 1844.","inputs":[]},{"name":"Cut into plugs","process":"cut","text":"The cured rod is cut into short cylinders, the plugs.","inputs":[]},{"name":"Check size and hardness","process":"inspect","text":"Inspectors measure plug size so they fit the ferrule, and test hardness so every batch erases the same way.","inputs":[]},{"name":"Press plugs into ferrules","process":"assemble","text":"At the pencil factory each plug is inserted into a ferrule, a metal cap of aluminum or brass. Glue or metal prongs hold it in place.","inputs":["aluminum","brass","adhesive"]}],"facts":["Before rubber, people erased pencil marks with crustless bread.","An 1858 patent for attaching an eraser to a pencil was later thrown out, because it only combined two existing tools.","About 90 percent of American pencils have a built-in eraser."],"where":[],"whereNote":null,"sources":[{"title":"The Evolution, Production, and Future of Erasers","url":"https://www.mfgrobots.com/Article/mfg/mpm/2210.html"},{"title":"Eraser","url":"https://en.wikipedia.org/wiki/Eraser"},{"title":"Vulcanization","url":"https://en.wikipedia.org/wiki/Vulcanization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ethanol","name":"Ethanol","kind":"material","category":"chemicals","title":"How ethanol is made","url":"https://assemblyline.org/make/ethanol","stations":6,"upstream":11,"downstream":169,"depth":4,"dek":"Fuel ethanol is made by fermenting corn or sugarcane, the same way beer is, just in far bigger tanks.","answer":"Fuel ethanol is made by milling corn or crushing sugarcane, cooking the starch and sugar into a sweet mash, and letting yeast ferment it into a weak alcohol beer. Distillation concentrates the alcohol, and a dehydration step removes the last water. A small share is made from ethylene instead.","aka":["ethyl alcohol","grain alcohol","fuel ethanol"],"inputs":["corn","sugarcane","water","yeast","ethylene"],"uses":["deodorant","perfume","vaccine","gasoline","ink","vanilla-extract","vinegar","gin","lacquer","super-glue","port-wine","insect-repellent","air-freshener","hairspray","mouthwash"],"grounds":["corn","sugarcane","water","natural-gas","sugar-beet","crude-oil"],"upstreamSlugs":["corn","sugarcane","water","yeast","ethylene","molasses","naphtha","natural-gas","sugar-beet","crude-oil","hydrogen"],"downstreamSlugs":["deodorant","perfume","vaccine","gasoline","ink","vanilla-extract","vinegar","gin","lacquer","super-glue","port-wine","insect-repellent","air-freshener","hairspray","mouthwash","shampoo","dish-soap","foundation-makeup","car","car-engine","motorcycle","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","ice-cream","cola","white-chocolate","caramel","mayonnaise","ketchup","mustard","hot-sauce","salsa","pickles","guitar","electric-guitar","trumpet","chopsticks","door","chess-set","saxophone","ukulele","felt-hat","baseball-bat","locomotive","vacuum-cleaner","electric-kettle","cotton-candy","pillow","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","electric-car","soap","toothpaste","detergent","nitrile-glove","washing-machine","paperclip","donut","corn-flakes","popcorn","crayon","fireworks","candle","fish-sticks","zip-bag","blender","dishwasher","cotton-swab","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","refrigerator","microwave-oven","pencil","scissors","mirror","airplane","container-ship","shipping-container","bicycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","padlock"],"steps":[{"name":"Mill the grain or crush the cane","process":"crush","text":"Corn kernels are ground to flour in hammer mills, or sugarcane is crushed to squeeze out its juice. Either way, the aim is to get at the sugars.","inputs":["corn","sugarcane"]},{"name":"Cook it into a sweet mash","process":"cook","text":"Corn flour is mixed with water and cooked, and enzymes chop its starch into simple sugars. Cane juice already contains sugar, so it skips this step.","inputs":["water"]},{"name":"Ferment with yeast","process":"ferment","text":"Yeast is added to the mash in huge tanks. It eats the sugar and produces alcohol and carbon dioxide, and the result is a weak alcohol mixture called beer.","inputs":["yeast"]},{"name":"Distill off the alcohol","process":"refine","text":"The beer is heated in tall columns, where ethanol vaporizes before the water. Ethanol and water form a mixture that cannot be separated completely by simple distillation.","inputs":[]},{"name":"Dry it to fuel grade","process":"separate","text":"Molecular sieve beds soak up the remaining water and leave nearly pure ethanol. Fuel plants add a small amount of gasoline to make it undrinkable.","inputs":[]},{"name":"Synthesize it from ethylene","process":"react","text":"A smaller share of ethanol is made by reacting ethylene with water over a catalyst. It starts from petrochemicals and skips the crops.","inputs":["ethylene"]}],"facts":["World fuel ethanol production reached 120 gigaliters in 2024.","Brazil made it mandatory to blend ethanol with gasoline in 1976, and the first production car running entirely on ethanol was the Fiat 147, introduced in Brazil in 1978.","A 70% ethanol solution kills microbes better than pure ethanol, because it relies on water to work."],"where":[{"place":"United States","share":"51% of world fuel ethanol"},{"place":"Brazil","share":"30% of world fuel ethanol"}],"whereNote":"Share of world fuel ethanol production in 2024.","sources":[{"title":"Ethanol","url":"https://en.wikipedia.org/wiki/Ethanol"},{"title":"Ethanol fuel","url":"https://en.wikipedia.org/wiki/Ethanol_fuel"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ethylene","name":"Ethylene","kind":"material","category":"chemicals","title":"How ethylene is made","url":"https://assemblyline.org/make/ethylene","stations":5,"upstream":5,"downstream":361,"depth":3,"dek":"Ethylene is made by heating naphtha or ethane in a furnace for a few thousandths of a second and then shock-cooling it.","answer":"Ethylene is made by steam cracking. Naphtha or ethane is mixed with steam and sent through furnace tubes at a very high temperature, where the molecules split in milliseconds. The gas is quenched at once to stop the reaction. Compressors and cold distillation columns then separate ethylene from propylene and other products.","aka":["ethene","C2H4","steam cracking"],"inputs":["naphtha","natural-gas","water"],"uses":["shampoo","polyethylene","pvc","pet-plastic","polystyrene","abs-plastic","synthetic-rubber","ethanol","plastic","styrene","polyvinyl-alcohol","ethylene-glycol"],"grounds":["natural-gas","water","crude-oil"],"upstreamSlugs":["naphtha","natural-gas","water","crude-oil","hydrogen"],"downstreamSlugs":["shampoo","polyethylene","pvc","pet-plastic","polystyrene","abs-plastic","synthetic-rubber","ethanol","plastic","styrene","polyvinyl-alcohol","ethylene-glycol","toothpaste","hip-implant","adhesive","plastic-bag","duct-tape","lithium-ion-cell","glass-bottle","frozen-peas","bubble-wrap","plastic-wrap","zip-bag","paper-cup","thermos","ski","snowboard","frisbee","sanitary-pad","power-cable","car-battery","backpack","flip-flops","usb-cable","diaper","credit-card","dishwasher","garden-hose","football","volleyball","yoga-mat","action-figure","fashion-doll","globe","inflatable-pool-toy","chain-link-fence","pvc-pipe","vinyl-floor","smoke-detector","vinyl-record","polyester","plastic-bottle","3d-printer-filament","drum-kit","bottled-water","surfboard","bike-helmet","ballpoint-pen","polystyrene-foam","foam-cup","compact-disc","inkjet-printer","lipstick","hearing-aid","thermometer","lego-brick","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","harmonica","suitcase","high-heels","wireless-earbuds","phone-charger","game-console","wifi-router","e-reader","graphics-card","remote-control","electric-toothbrush","toothbrush","syringe","rubber","nitrile-glove","chewing-gum","tire","golf-ball","basketball","pencil-eraser","rubber-boots","deodorant","perfume","vaccine","gasoline","ink","vanilla-extract","vinegar","gin","lacquer","super-glue","port-wine","insect-repellent","air-freshener","hairspray","mouthwash","led","aa-battery","solar-panel","refrigerator","washing-machine","vacuum-cleaner","nonstick-pan","marker-pen","highlighter","fountain-pen","printer-toner","toaster","roller-skates","tennis-racket","bowling-ball","dice","yo-yo","board-game","jigsaw-puzzle","trading-cards","snow-globe","toy-car","tampon","wet-wipes","asthma-inhaler","prosthetic-leg","wheelchair","light-switch","power-outlet","seat-belt","eyeglass-frame","microphone","umbrella","pvb","banknote","spandex","adhesive-bandage","led-bulb","ev-battery","pencil","nail","insulation","popcorn","windshield","skateboard","guitar","piano","violin","tennis-ball","baseball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","clear-tape","staple","sofa","ice-skates","golf-club","fishing-rod","cricket-bat","dartboard","chess-set","kite","ukulele","cello","drumstick","pinball-machine","kitchen-sponge","cotton-swab","roof-shingle","double-glazed-window","brake-pad","sailboat","dress-shirt","suit","raincoat","handbag","wallet","hiking-boots","smartwatch","loudspeaker","camera-lens","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","sneaker","leather-shoe","baseball-cap","carpet","mattress","electric-kettle","cotton-candy","pillow","smartphone","drone","satellite","digital-camera","nail-polish","penicillin","insulin","ketchup","cola","sparkling-water","beer","wine","champagne","whiskey","vodka","rum","tequila","sake","hard-cider","hot-sauce","soda","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","prosecco","non-alcoholic-beer","candy-cane","soccer-ball","office-chair","canoe","hoodie","leggings","swimsuit","shoelace","curtain","flag","zipper","button","thread","teddy-bear","sunscreen","aspirin","detergent","bleach","vitamin-c","dish-soap","hair-dye","foundation-makeup","cough-syrup","shipping-container","dumbbell","treadmill","ladder","wheelbarrow","fire-extinguisher","car","electric-car","bicycle","motorcycle","car-engine","tin-can","aluminum-can","wallpaper","candy-coated-chocolate","floor-tile","underwear","newspaper","t-shirt","ice-cream","white-chocolate","caramel","mayonnaise","mustard","salsa","pickles","electric-guitar","trumpet","chopsticks","saxophone","felt-hat","baseball-bat","lcd-screen","aluminum-window-frame","ceiling-fan","fireworks","cake-mix","energy-drink","soap","paperclip","donut","corn-flakes","crayon","candle","canned-meat","fish-sticks","blender","facial-tissue","down-jacket","jeans","airbag","silk-tie","winter-gloves","leather-belt","blanket","socks","sweater","towel","flour","locomotive","paint","condensed-milk","baby-formula","coconut-milk","canned-soup","light-beer","bread","instant-noodles","tortilla","croissant","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","modeling-clay","licorice","microwave-oven","scissors","mirror","airplane","container-ship","water-bottle","water-heater","billiard-ball","coil-spring","hammer","gas-cylinder","neon-sign","suspension-bridge-cable","subway-train","toffee","padlock"],"steps":[{"name":"Choose the feed","process":"mix","text":"Plants in Europe and Asia mostly crack naphtha, and plants with cheap natural gas often crack ethane. The feed decides the mix of products that comes out.","inputs":["naphtha","natural-gas"]},{"name":"Crack it with steam","process":"react","text":"Feed and steam run through tubes in a furnace at about 850 °C. The reaction takes only milliseconds, and the molecules break into smaller ones including ethylene and propylene.","inputs":["water"],"spec":"about 850 °C"},{"name":"Quench the hot gas","process":"chill","text":"The gas is cooled almost at once in a heat exchanger or with a spray of oil. Without this shock, the molecules would keep reacting and fall apart into carbon and hydrogen.","inputs":[]},{"name":"Compress and dry the gas","process":"press","text":"Multistage compressors squeeze the cooled gas, and acid gases and water are scrubbed out. Chilling is much easier when the gas is dry and compressed.","inputs":[]},{"name":"Distill it in the cold","process":"refine","text":"A string of very cold columns separates hydrogen, methane, ethylene, propylene and heavier products one at a time. Ethylene leaves as a nearly pure gas and goes to nearby plastics plants by pipe.","inputs":[]}],"facts":["World ethylene production passed 225 million tonnes in 2022, more than any other organic compound.","Ethylene is a plant hormone, and farmers use it to trigger ripening in fruit."],"where":[],"whereNote":null,"sources":[{"title":"Ethylene","url":"https://en.wikipedia.org/wiki/Ethylene"},{"title":"Steam cracking","url":"https://en.wikipedia.org/wiki/Steam_cracking"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ethylene-glycol","name":"Ethylene glycol","kind":"material","category":"chemicals","title":"How ethylene glycol is made","url":"https://assemblyline.org/make/ethylene-glycol","stations":6,"upstream":15,"downstream":110,"depth":4,"dek":"Your polyester shirt and your car's antifreeze share one sweet-tasting, toxic ingredient.","answer":"Ethylene gas is oxidized over silver to make ethylene oxide, a reactive three-membered ring. Water then pops the ring open, and a large excess of water keeps the molecules from reacting further. After the water is boiled off and heavier glycols are split away, the syrupy liquid goes to polyester plants and antifreeze blenders.","aka":["antifreeze","MEG","monoethylene glycol","ethane-1,2-diol"],"inputs":["ethylene","oxygen","water","carbon-dioxide"],"uses":["pet-plastic","spandex"],"grounds":["water","natural-gas","air","corn","limestone","crude-oil","sugarcane","sugar-beet"],"upstreamSlugs":["ethylene","oxygen","water","carbon-dioxide","naphtha","natural-gas","air","corn","yeast","limestone","crude-oil","hydrogen","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["pet-plastic","spandex","polyester","plastic-bottle","credit-card","3d-printer-filament","drum-kit","bottled-water","underwear","leggings","swimsuit","tire","soccer-ball","marker-pen","highlighter","sofa","office-chair","pillow","garden-hose","volleyball","kite","kitchen-sponge","wet-wipes","seat-belt","canoe","sailboat","hoodie","raincoat","backpack","suitcase","shoelace","curtain","flag","wireless-earbuds","microphone","sneaker","mattress","umbrella","zipper","button","thread","teddy-bear","shampoo","sunscreen","aspirin","detergent","bleach","vitamin-c","ketchup","cola","sparkling-water","soda","dish-soap","hair-dye","foundation-makeup","mouthwash","cough-syrup","car","electric-car","bicycle","motorcycle","down-jacket","handbag","jeans","dress-shirt","suit","baseball-cap","airbag","baseball","fireworks","bike-helmet","candle","ice-skates","fishing-rod","football","yo-yo","fashion-doll","tampon","silk-tie","winter-gloves","leather-belt","wallet","hiking-boots","high-heels","felt-hat","blanket","book","t-shirt","socks","sweater","leather-shoe","towel","flour","bread","instant-noodles","tortilla","croissant","donut","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","fish-sticks","modeling-clay","licorice","cake-mix"],"steps":[{"name":"Oxidize over silver","process":"react","text":"Ethylene and oxygen pass over a silver catalyst in a closed reactor and form ethylene oxide. A part of the ethylene burns all the way to carbon dioxide. The oxide is a very hazardous substance and stays sealed inside the plant.","inputs":["ethylene","oxygen"]},{"name":"Open the ring with water","process":"react","text":"The oxide reacts with water, which breaks its strained ring and gives two hydroxyl groups. A large excess of water keeps the new glycol from reacting with more oxide. Yields reach 90% this way.","inputs":["water"]},{"name":"Or go through carbonate","process":"react","text":"Shell's OMEGA process first reacts the oxide with carbon dioxide, partly recovered from the first step, to make ethylene carbonate. Water then opens this with a base catalyst, reaching 98% selectivity.","inputs":["carbon-dioxide"]},{"name":"Boil off the water","process":"refine","text":"All that surplus water has to come off again, and this separation takes a lot of energy. It is the main drawback of the plain water route.","inputs":[]},{"name":"Split the glycol family","process":"refine","text":"Columns separate the main product from its heavier cousins, diethylene, triethylene and tetraethylene glycol. The clean liquid boils at 198 °C.","inputs":[]},{"name":"Send it two ways","process":"fill","text":"Most goes to polyester fiber and resin plants, and the rest largely to antifreeze blenders. A half-and-half mix with water freezes at −37 °C and boils at 129 °C, which suits car radiators.","inputs":[]}],"facts":["Charles-Adolphe Wurtz first prepared ethylene glycol in 1856, and named it for its likeness to both ethyl alcohol and glycerin.","Ethylene oxide became industrially important in the First World War as a route to glycol coolant.","Ethylene glycol tastes sweet but is toxic in high concentrations."],"where":[],"whereNote":null,"sources":[{"title":"Ethylene glycol","url":"https://en.wikipedia.org/wiki/Ethylene_glycol"},{"title":"Ethylene oxide","url":"https://en.wikipedia.org/wiki/Ethylene_oxide"},{"title":"Ethylene glycol (Britannica)","url":"https://www.britannica.com/science/ethylene-glycol"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"eyeglass-frame","name":"Eyeglass frame","kind":"product","category":"textiles","title":"How eyeglass frames are made","url":"https://assemblyline.org/make/eyeglass-frame","stations":8,"upstream":90,"downstream":0,"depth":10,"dek":"Acetate frames tumble for 48 to 76 hours in barrels of beech and birch chips to lose their milling marks.","answer":"Plastic eyeglass frames are milled from a block of cellulose acetate, heat-pressed for a nose bridge, then tumbled in barrels of wood chips for days and buffed by hand. Hinges and temples go on after polishing, and lenses last. Metal frames start as wire on a reeling machine, with the parts welded together by hand.","aka":["spectacle frame","glasses frame","eyewear frame"],"inputs":["plastic","cellulose-acetate","pigment","acetone","nickel","solder","paint","steel","screw","eyeglass-lens"],"uses":[],"grounds":["natural-gas","water","iron-ore","sulfur","air","nickel-ore","crude-oil","timber","titanium-ore","tin-ore","lead-ore","silver-ore","zinc-ore","copper-ore","limestone","dolomite","manganese-ore","silica-sand","rock-salt","coal","quartz","trona","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["plastic","cellulose-acetate","pigment","acetone","nickel","solder","paint","steel","screw","eyeglass-lens","naphtha","natural-gas","ethylene","propylene","wood-pulp","acetic-anhydride","water","plasticizer","iron-ore","titanium-dioxide","carbon-black","sulfur","benzene","air","nickel-ore","sulfuric-acid","tin","lead","silver","copper","acrylic","tin-can","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","steel-wire","zinc","polycarbonate","glass","crude-oil","hydrogen","timber","caustic-soda","hydrogen-peroxide","methanol","carbon-monoxide","titanium-ore","chlorine","coke","toluene","tin-ore","lead-ore","silver-ore","zinc-ore","copper-ore","ammonia","tinplate","lacquer","ink","limestone","dolomite","silicon","propane","manganese-ore","phenol","silica-sand","soda-ash","rock-salt","coal","ethanol","vegetable-oil","phenolic-resin","quartz","charcoal","carbon-dioxide","trona","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","formaldehyde","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Press the acetate block","process":"press","text":"Pigments are mixed with acetone and worked into small acetate chips. Mixed chips go into a mold and are pressed, and 24 hours later they have fused into one block.","inputs":["plastic","cellulose-acetate","pigment","acetone"],"spec":"24 hours"},{"name":"Face and mill the blanks","process":"machine","text":"Raw sheet varies in thickness, so a milling machine faces both sides to an even 8 mm. CNC tools then cut the fronts and temples, with their curves, lens grooves and rivet holes.","inputs":[],"spec":"faced to 8 mm"},{"name":"Heat-press the bridge","process":"press","text":"The front is softened in an oven and put straight under a pneumatic press. A brass wedge shaped like a nose presses down, forming the bridge and curving the front.","inputs":[]},{"name":"Tumble in wood chips","process":"grind","text":"Fronts and temples ride in barrels of beech and birch chips with polishing paste for 48 to 76 hours. Slow abrasion takes off the sharp edges and tool marks.","inputs":[],"spec":"48 to 76 hours"},{"name":"Buff by hand","process":"grind","text":"Each piece is buffed several times on a polishing wheel, and a wax compound brings up the gloss.","inputs":[]},{"name":"Build the metal frames","process":"weld","text":"Metal frames follow their own route. Wire takes shape in a reeling machine, and the rim is welded by hand to the bridge, temples and nose pad wires, then plated or painted.","inputs":["nickel","solder","paint"]},{"name":"Attach hinges and temples","process":"assemble","text":"Hinges are riveted or melted into the acetate, and the temples are screwed on by hand. Core wires go inside each temple so it holds its shape but can still be adjusted.","inputs":["steel","screw"]},{"name":"Fit lenses and adjust","process":"assemble","text":"Lenses are cut to fit each frame and inserted by hand. The finished glasses get a last check of the prescription.","inputs":["eyeglass-lens"]}],"facts":["The temple arms that hook over the ears were not invented until the 1700s.","Nylon frames are favored for sports glasses because they are light and flexible."],"where":[],"whereNote":null,"sources":[{"title":"Glasses","url":"https://en.wikipedia.org/wiki/Glasses"},{"title":"How our glasses are made (Warby Parker)","url":"https://www.warbyparker.com/how-our-glasses-are-made"},{"title":"How glasses are made (Banton Frameworks)","url":"https://www.bantonframeworks.co.uk/blogs/manufacture/how-glasses-are-made"},{"title":"How our frames are made (Oscar Wylee)","url":"https://www.oscarwylee.com.au/how-ow-frames-are-made.html"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"eyeglass-lens","name":"Eyeglass lens","kind":"product","category":"minerals","title":"How eyeglass lenses are made","url":"https://assemblyline.org/make/eyeglass-lens","stations":6,"upstream":31,"downstream":1,"depth":7,"dek":"The law that sets how thin a lens may be is a steel ball dropped on it from 50 inches.","answer":"Most eyeglass lenses today are molded plastic blanks. Opticians grind the front and back surfaces to the prescription curve, polish them clear, trim the edge to fit the frame, and add a hard scratch-resistant coating. In the US, lenses must survive a ball-drop impact test, which sets a minimum thickness.","aka":["spectacle lens","prescription lens","glasses lens"],"inputs":["polycarbonate","glass"],"uses":["eyeglass-frame"],"grounds":["silica-sand","limestone","air","crude-oil","rock-salt","water","trona","sulfur","natural-gas","corn","coal","sugarcane","sugar-beet"],"upstreamSlugs":["polycarbonate","glass","phenol","propylene","acetone","caustic-soda","chlorine","silica-sand","soda-ash","limestone","benzene","air","naphtha","crude-oil","rock-salt","water","sulfuric-acid","ammonia","carbon-dioxide","lime","trona","hydrogen","toluene","sulfur","natural-gas","corn","yeast","coal","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["eyeglass-frame"],"steps":[{"name":"Mold the lens blank","process":"mold","text":"Lenses are ground, polished or molded from clear material. Plastic is the most commonly prescribed type, mainly CR-39, polycarbonate or Trivex. Glass lenses are less common because they are heavier and can shatter.","inputs":["polycarbonate","glass"]},{"name":"Grind the prescription curves","process":"grind","text":"The power of a lens comes from the difference in curvature between its front and back surfaces. A lab grinds the back surface to match the wearer's prescription, usually starting from a front curve that is already set.","inputs":[]},{"name":"Polish to clarity","process":"grind","text":"Fine abrasives polish the ground surface until it is smooth and clear. Spherical surfaces are by far the easiest shape to grind and polish accurately.","inputs":[]},{"name":"Add the hard coat","process":"coat","text":"Polycarbonate scratches easily, so a scratch-resistant coating is typically applied after shaping and polishing. Anti-reflective coatings matter more on higher-index lenses, which bounce back more light.","inputs":[]},{"name":"Trim to fit the frame","process":"cut","text":"The round lens is edged to the outline of the chosen frame. Very thick lenses for strong nearsightedness are sometimes beveled to reduce the flare of a thick edge.","inputs":[]},{"name":"Drop-test the thickness","process":"inspect","text":"Lens samples face a test in which a 0.56-ounce steel ball is dropped from 50 inches. That test effectively sets the minimum thickness: 2.0 mm for glass or CR-39, but 1.5 mm or even 1.0 mm for some newer materials.","inputs":[],"spec":"ball dropped from 50 inches"}],"facts":["Trivex was developed in 2001 by PPG Industries for the military as transparent armor.","Trivex, at 1.1 g/cm3, is the lightest common corrective lens material, while optical crown glass, at 2.56 g/cm3, is the heaviest.","Glass lenses can now be made with a refractive index up to 1.9, for extremely high prescriptions."],"where":[],"whereNote":null,"sources":[{"title":"Corrective lens","url":"https://en.wikipedia.org/wiki/Corrective_lens"},{"title":"Glasses","url":"https://en.wikipedia.org/wiki/Glasses"},{"title":"Lens","url":"https://en.wikipedia.org/wiki/Lens"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"eyeshadow","name":"Eyeshadow","kind":"product","category":"body-health","title":"How eyeshadow is made","url":"https://assemblyline.org/make/eyeshadow","stations":5,"upstream":41,"downstream":0,"depth":6,"dek":"A pan of eyeshadow is about a third crushed mineral filler, and the shimmer is mostly mica.","answer":"Eyeshadow is a balance of fillers, pigments, binders, slip agents and preservatives. Fillers such as mica, talc or kaolin clay make up about 30 percent of a powder. The blend is mixed and pulverized, then pressed into metal pans, usually with a silk ribbon between the die and the powder to keep the surface matte.","aka":["eye shadow","eye color","eyelid shimmer"],"inputs":["mica","kaolin","silicone","paraffin-wax","nylon","pigment","aluminum"],"uses":[],"grounds":["mica","kaolin","water","silica-sand","crude-oil","iron-ore","sulfur","coal","quartz","timber","natural-gas","air","titanium-ore","bauxite","rock-salt","limestone"],"upstreamSlugs":["mica","kaolin","silicone","paraffin-wax","nylon","pigment","aluminum","silicon","methanol","hydrochloric-acid","water","silica-sand","crude-oil","hydrogen","benzene","nitric-acid","ammonia","iron-ore","titanium-dioxide","carbon-black","sulfur","coal","petroleum-coke","alumina","quartz","coke","charcoal","timber","natural-gas","chlorine","naphtha","toluene","air","titanium-ore","oxygen","sulfuric-acid","bauxite","caustic-soda","lime","rock-salt","limestone"],"downstreamSlugs":[],"steps":[{"name":"Weigh the fillers","process":"mix","text":"Mineral fillers such as mica, talc and kaolin clay give the shadow bulk and texture. They make up about 30 percent of eyeshadow powders and 25 percent of cream shadows.","inputs":["mica","kaolin"]},{"name":"Bind and add slip","process":"mix","text":"Binders such as silicone or paraffin wax help the shadow stick to skin. Slip agents such as silica and nylon powders let it glide on smoothly, and preservatives keep bacteria out.","inputs":["silicone","paraffin-wax","nylon"]},{"name":"Add the color","process":"mix","text":"Mica powders, iron oxides and clays supply the color pigments. Color and pearl both depend on how long and how hard the batch is mixed, since too much work breaks up pearlescent particles and dulls the shimmer.","inputs":["pigment"]},{"name":"Pulverize the blend","process":"grind","text":"Hammer, pebble or air mills break the blended powder down. The batch should go on to pressing straight away, or be stored in airtight containers.","inputs":[]},{"name":"Press into pans","process":"press","text":"Air, hydraulic or cam presses compress the powder into pans of steel, tin or aluminum. Pressures usually run from 300 to 2000 psi, and eyeshadow is pressed harder than face powder but softer than rouge.","inputs":["aluminum"],"spec":"300 to 2000 psi"}],"facts":["A ribbon of silk is usually laid between the die and the powder before each press, to keep the surface of the cake matte.","Press too hard and a powder becomes a hard tablet that barely transfers to a brush, press too soft and the cake crumbles.","The earliest direct archaeological evidence for eye makeup, in predynastic Egypt, shows green malachite and black galena as the pigments."],"where":[],"whereNote":null,"sources":[{"title":"Eye shadow","url":"https://en.wikipedia.org/wiki/Eye_shadow"},{"title":"Pressed powders (Journal of the Society of Cosmetic Chemists)","url":"https://library.scconline.org/v022n10/15"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"facial-tissue","name":"Facial tissue","kind":"product","category":"wood-paper","title":"How facial tissue is made","url":"https://assemblyline.org/make/facial-tissue","stations":6,"upstream":55,"downstream":0,"depth":10,"dek":"Facial tissue is scraped off a hot steel drum with a blade, and that scrape makes the crinkle that gives it stretch.","answer":"Facial tissue is the lightest, softest paper. A machine lays a very thin web of pure chemical pulp, dries it on a steam drum and scrapes it off to make it crinkly. It is lightly smoothed, sometimes treated with softeners or lotion, layered into two or three plies, folded and packed into boxes.","aka":["tissues","paper handkerchief","Kleenex"],"inputs":["wood-pulp","water","cardboard-box"],"uses":[],"grounds":["water","timber","rock-salt","limestone","air","natural-gas","soybeans","rapeseed","clay","crude-oil","titanium-ore","iron-ore","sulfur","corn","sugarcane","coal","sugar-beet"],"upstreamSlugs":["wood-pulp","water","cardboard-box","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","cardboard","ink","adhesive","rock-salt","limestone","air","hydrogen","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","natural-gas","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","ethylene","propylene","ammonia","methanol","acetone","nitric-acid","benzene","coal","molasses","naphtha","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Slurry the pure fibers","process":"mix","text":"The sheet is made entirely from chemical pulp, sometimes with some selected recycled fiber. Using purer pulp gives a cleaner, softer and stronger sheet.","inputs":["wood-pulp","water"]},{"name":"Float a featherweight web","process":"cast","text":"The slurry forms a very thin web between a wire and a felt, then is pressed onto a large drying drum. Facial tissue is the lowest weight of all tissue grades.","inputs":[],"spec":"14 to 18 g/m²"},{"name":"Scrape off the drum","process":"dry","text":"A blade peels the dried web from the drum and crinkles it, which gives the sheet its stretch and its softness.","inputs":[]},{"name":"Smooth it lightly","process":"roll","text":"A light pass between rollers makes the surface smoother without flattening the crinkle completely.","inputs":[]},{"name":"Treat with softeners","process":"coat","text":"The base tissue may be treated with softeners or lotion, and some is perfumed, to get the feel the brand is selling. Strength additives that do not break down easily may be added too.","inputs":[]},{"name":"Ply, fold and box","process":"package","text":"Two or three plies are layered, folded in an interleaved stack and put into pocket packs or boxes.","inputs":["cardboard-box"]}],"facts":["Tissue grades that absorb the most water are made by drying with hot air blown through the sheet, which uses about twice the energy of ordinary drying.","Facial tissue is usually 2 or 3 plies of paper, each only 14 to 18 grams per square meter."],"where":[],"whereNote":null,"sources":[{"title":"Facial tissue","url":"https://en.wikipedia.org/wiki/Facial_tissue"},{"title":"Tissue paper","url":"https://en.wikipedia.org/wiki/Tissue_paper"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"fashion-doll","name":"Fashion doll","kind":"product","category":"play","title":"How fashion dolls are made","url":"https://assemblyline.org/make/fashion-doll","stations":7,"upstream":71,"downstream":0,"depth":10,"dek":"A doll's hair is sewn into its vinyl scalp on a special sewing machine run by hand.","answer":"A fashion doll is molded plastic. Torso and limbs are formed from PVC and the head from a harder vinyl. The face takes the longest, up to 15 painting steps. Nylon hair is then rooted through the scalp by a sewing machine and styled, the parts are joined, tiny clothes go on, and the doll is posed and boxed by hand.","aka":["Barbie","doll","fashion dolls"],"inputs":["pvc","paint","nylon","thread"],"uses":[],"grounds":["water","natural-gas","rock-salt","iron-ore","sulfur","air","titanium-ore","crude-oil","coal","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","limestone","dolomite","manganese-ore","quartz","timber","sugar-beet"],"upstreamSlugs":["pvc","paint","nylon","thread","ethylene","chlorine","water","pigment","plasticizer","titanium-dioxide","acrylic","tin-can","benzene","nitric-acid","ammonia","polyester","naphtha","natural-gas","rock-salt","sulfuric-acid","iron-ore","carbon-black","sulfur","air","propylene","titanium-ore","coke","oxygen","methanol","tinplate","lacquer","ink","hydrogen","toluene","pet-plastic","crude-oil","coal","steel","tin","ethanol","vegetable-oil","phenolic-resin","p-xylene","ethylene-glycol","pig-iron","magnesium","steel-scrap","lime","manganese","argon","tin-ore","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","carbon-dioxide","limestone","dolomite","silicon","propane","manganese-ore","molasses","quartz","charcoal","timber","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the body parts","process":"mold","text":"Plastic is shaped in molds to form torso, arms and legs. Barbie's body is PVC, and a special doll such as a mermaid gets its own molds for the torso and tail.","inputs":["pvc"]},{"name":"Mold the head","process":"mold","text":"The head is a separate part in a harder vinyl. A new face often reuses an old head mold, as the 1967 Francie did.","inputs":["pvc"]},{"name":"Paint the face","process":"coat","text":"Eyes go in or are painted on, lips and brows are shaped, and makeup is airbrushed on. This can run to 15 steps, and no other part takes as long.","inputs":["paint"],"spec":"up to 15 steps"},{"name":"Root the hair","process":"sew","text":"A hand-operated sewing machine punches nylon fibers through the scalp. More hair makes a fuller style, but denser rooting costs more. The hair is then brushed, trimmed and styled.","inputs":["nylon"]},{"name":"Join head, limbs and torso","process":"assemble","text":"The finished head and the limbs are fixed to the torso.","inputs":[]},{"name":"Sew and fit the clothes","process":"sew","text":"Outfits are sewn and put on the doll, loose threads are cut, and plastic accessories are painted by hand.","inputs":["thread"]},{"name":"Pose and box","process":"package","text":"Because of the poses and the plastic pieces that hold the doll in place, this step is done entirely by hand.","inputs":[]}],"facts":["Barbie was based on the German Bild Lilli doll, which creator Ruth Handler bought while in Europe.","Barbie sold about 350,000 units in her first year, and demand beat Mattel's ability to produce her for the first three years.","From first draft to final product, a new Barbie can take three to eighteen months."],"where":[],"whereNote":null,"sources":[{"title":"Building Barbie","url":"https://tomorrowsworldtoday.com/?p=1585"},{"title":"Barbie","url":"https://en.wikipedia.org/wiki/Barbie"},{"title":"Method of making a permanent doll wig","url":"https://patents.google.com/patent/US4674169"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"faucet","name":"Faucet","kind":"product","category":"hardware","title":"How faucets are made","url":"https://assemblyline.org/make/faucet","stations":11,"upstream":44,"downstream":0,"depth":6,"dek":"A faucet's water channels start as sand: a core sits inside the mold, then gets whirled out with metal balls.","answer":"Water channels begin as a core of fine sand set inside a shell mold, and molten brass flows around it. At Oras in Finland, about 3,000 faucets a day go on from there: core whirled out, castings sawn apart, machined, ground, polished, then chrome-plated over roughly two hours. Cartridges go in at assembly, and 1 percent get spot checks.","aka":["tap","water tap"],"inputs":["brass","nickel","chromium","copper","ceramic"],"uses":[],"grounds":["nickel-ore","chromite","limestone","air","water","copper-ore","clay","kaolin","feldspar","quartz","zinc-ore","lead-ore","tin-ore","crude-oil","coal","sulfur","rock-salt","trona","bauxite","natural-gas","corn","sugarcane","sugar-beet"],"upstreamSlugs":["brass","nickel","chromium","copper","ceramic","zinc","lead","tin","aluminum","nickel-ore","sulfuric-acid","chromite","coke","soda-ash","limestone","air","water","copper-ore","oxygen","clay","kaolin","feldspar","quartz","zinc-ore","lead-ore","tin-ore","crude-oil","coal","petroleum-coke","alumina","sulfur","rock-salt","ammonia","carbon-dioxide","lime","trona","bauxite","caustic-soda","natural-gas","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Bake the sand cores","process":"mold","text":"Fine sand and a hardening agent are heated in a core box until solid. The core is what will leave the water channels open inside the casting.","inputs":[]},{"name":"Prepare the shell mold","process":"assemble","text":"A shell mold is dipped in a solution of water and graphite. Next, the caster sets the cores inside and blows out loose sand with compressed air.","inputs":[]},{"name":"Pour the brass","process":"cast","text":"The furnace melts bars of dezincification-resistant brass, a grade Oras picks because acidic Nordic tap water corrodes normal brass. The sealed mold goes into the casting chamber, and molten metal flows into the molds and around the cores.","inputs":["brass"]},{"name":"Whirl out the core","process":"machine","text":"After brief cooling, tongs move the casting aside. A mill full of metal balls then tumbles it until the sand core breaks out from inside.","inputs":[]},{"name":"Saw the casts apart","process":"cut","text":"Saws separate the joined bodies and take off parts needed only for casting. Sawing waste goes straight back into the furnace, and machining chips return to the brass supplier.","inputs":[]},{"name":"Machine the body","process":"machine","text":"A conveyor carries the bodies through automated machining. Small batches of special products may be finished by hand.","inputs":[]},{"name":"Grind and polish","process":"grind","text":"Grinding takes out the rough cast surface and polishing leaves it flawless. After this, bare hands stay off, because fingerprints would show through the plating.","inputs":[]},{"name":"Chrome-plate the parts","process":"coat","text":"Parts go through soaking and washing stages 40 times in about two hours, and chrome highlights any surface flaw. Visible plastic parts first get copper and then nickel layers, which protect against thermal expansion.","inputs":["nickel","chromium","copper"]},{"name":"Inspect and laser-mark","process":"inspect","text":"Plated products are inspected before assembly. Brand logos and other markings go on now, mostly by laser.","inputs":[]},{"name":"Install the cartridge","process":"assemble","text":"The cartridge that regulates flow and temperature goes in, by hand or machine. Its ceramic discs slide over each other with very little friction.","inputs":["ceramic"]},{"name":"Spot-check and pack","process":"inspect","text":"Final inspection stays manual, and 1 percent of completed faucets get spot checks. Sound levels are tested separately, in a silent room with a floating concrete floor.","inputs":[]}],"facts":["Guest and Chrimes, brass founders in Rotherham, patented a screw-down tap in 1845, the first of its kind.","Ceramic valve discs take advantage of the very low friction between two ceramic surfaces in contact.","Oras says most of the metal in its delivered bars is recycled, because its sawing waste and machining chips get melted back in."],"where":[],"whereNote":null,"sources":[{"title":"From brass bars into faucets: this is how Oras faucets are made","url":"https://stories.oras.com/en/from-brass-bars-into-faucets-this-is-how-oras-faucets-are-made"},{"title":"This is how HANSA faucets are made","url":"https://stories.hansa.com/en/building-durability-into-every-faucet-this-is-how-hansa-faucets-are-made"},{"title":"Tap (valve)","url":"https://en.wikipedia.org/wiki/Tap_(valve)"},{"title":"Brass","url":"https://en.wikipedia.org/wiki/Brass"},{"title":"Electroplating","url":"https://en.wikipedia.org/wiki/Electroplating"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"feldspar","name":"Feldspar","kind":"raw","category":"ground","title":"How feldspar is mined","url":"https://assemblyline.org/make/feldspar","stations":5,"upstream":0,"downstream":11,"depth":0,"dek":"Feldspar is the most abundant mineral group in the crust, and glassmakers buy it for the aluminum it supplies.","answer":"Feldspar mills chase iron out of pale rock. Ore quarried from pegmatite or granite-like dikes is crushed and rod-milled to under 20 mesh, a coarse grain with few fines. Slimes wash off, then acid flotation lifts away mica and iron-bearing minerals, and a second float raises feldspar away from quartz. The concentrate is filtered and dried, then sold to glass and ceramics makers.","aka":["felspar"],"inputs":[],"uses":["ceramic","porcelain","toilet","floor-tile","pottery"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["ceramic","porcelain","toilet","floor-tile","pottery","hip-implant","faucet","turbine-blade","snow-globe","jet-engine","airplane"],"steps":[{"name":"Quarry the pale rock","process":"mine","text":"Ore generally comes from open pits in pegmatites or large dikes, mixed with quartz, mica and garnet. Trucks haul it to the mill.","inputs":[]},{"name":"Crush and rod-mill","process":"crush","text":"Two stages of crushing feed a rod mill, which makes a granular product with little slime. Markets want minus 20 mesh, and a spiral screen removes coarse mica and hard quartz pieces as waste.","inputs":[],"spec":"minus 20 mesh"},{"name":"Wash out the slimes","process":"wash","text":"Rake classifiers and a hydroclassifier send the finest particles to waste, since the float needs a slime-free feed. The sand then gets intense stirring with acid reagents in a heavily built conditioner.","inputs":[]},{"name":"Float off mica and iron","process":"separate","text":"In an acid circuit, mica, garnet and other iron-bearing minerals rise in the froth and go to waste. Some plants float the mica first and the iron minerals afterward.","inputs":[]},{"name":"Float and dry the product","process":"separate","text":"A final acid float lifts the product away from quartz. Classifiers and vacuum filters take it down to 7 to 9% moisture, a rotary dryer removes the rest, and a screen catches stray scale on its way to the silos.","inputs":[]}],"facts":["About 66% of feldspar in the United States is used in glassmaking.","In ceramics, feldspar acts as a flux, helping glassy material to form in the body of the ware during firing.","Roughly 60% of Earth's crust is feldspar."],"where":[{"place":"Turkey","share":"7.6 million tonnes"},{"place":"India","share":"5 million tonnes"},{"place":"Italy","share":"4 million tonnes"}],"whereNote":"Feldspar mined in 2020, from USGS estimates; world production was 26 million tonnes.","sources":[{"title":"Feldspar Beneficiation & Flotation Process","url":"https://www.911metallurgist.com/blog/feldspar-beneficiation-flotation-process/"},{"title":"Feldspar","url":"https://en.wikipedia.org/wiki/Feldspar"},{"title":"Granite","url":"https://en.wikipedia.org/wiki/Granite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"felt-hat","name":"Felt hat","kind":"product","category":"textiles","title":"How felt hats are made","url":"https://assemblyline.org/make/felt-hat","stations":8,"upstream":29,"downstream":0,"depth":8,"dek":"An Akubra hat starts as a cone of rabbit fur nearly three times the size of the finished hat.","answer":"A felt hat is made without any weaving. Rabbit fur or wool fibers are blown onto a cone, then matted together with heat, moisture and pressure until they lock into a dense felt that has shrunk to a fraction of its size. The body is dyed, stiffened, steamed over a block to form crown and brim, sanded and trimmed.","aka":["fedora","wool felt hat","bowler hat"],"inputs":["fleece","lacquer","thread"],"uses":[],"grounds":["fleece","water","corn","sugarcane","natural-gas","crude-oil","air","sulfur","sugar-beet","limestone"],"upstreamSlugs":["fleece","lacquer","thread","ethanol","acrylic","polyester","water","corn","sugarcane","yeast","ethylene","propylene","ammonia","sulfuric-acid","methanol","pet-plastic","molasses","naphtha","natural-gas","crude-oil","air","sulfur","p-xylene","ethylene-glycol","sugar-beet","hydrogen","oxygen","carbon-dioxide","limestone"],"downstreamSlugs":[],"steps":[{"name":"Form a loose fiber cone","process":"mix","text":"Cleaned rabbit fur or wool is blended and blown onto a large rotating cone, forming a thin, loose layer. At this point it is nearly three times the size of the finished hat.","inputs":["fleece"]},{"name":"Mat it with hot water","process":"knead","text":"Heat, moisture and pressure make the fibers shrink and interlock. The scales on each fiber latch onto their neighbors, and the cone holds together as felt.","inputs":[]},{"name":"Bump the felt","process":"knead","text":"The body passes through bumping machines, worked with heat and moisture. Short fibers bind into the surface, and the felt gets denser and smoother as it shrinks further.","inputs":[]},{"name":"Dye the body","process":"dye","text":"The felt goes into a heated dye bath, with shades mixed and weighed by hand. Rollers then help set the color and prepare the felt for shaping.","inputs":[]},{"name":"Stiffen the felt","process":"coat","text":"A shellac or resin stiffener is worked into the body, so the finished hat will hold its shape.","inputs":["lacquer"]},{"name":"Block it over a form","process":"press","text":"The damp body is steamed until it softens, then stretched over a wooden or metal hat block for the crown and pressed onto a flange for the brim.","inputs":[]},{"name":"Sand the surface","process":"grind","text":"Fine abrasives and sanding machines take off stray fibers, a step known as pouncing. Brushes and polishing wheels then even out the texture.","inputs":[]},{"name":"Trim and sew","process":"sew","text":"The edge is trimmed, a sweatband is sewn inside, and a ribbon goes around the crown.","inputs":["thread"]}],"facts":["Akubra counts 162 steps in making one hat.","Wool felt is among the oldest known textiles."],"where":[],"whereNote":null,"sources":[{"title":"Felt","url":"https://en.wikipedia.org/wiki/Felt"},{"title":"Hat-making","url":"https://en.wikipedia.org/wiki/Hat-making"},{"title":"Handcrafting an Akubra","url":"https://akubra.com.au/pages/handcrafting-an-akubra"},{"title":"How a felt hat is made: Christys' factory visit (Permanent Style)","url":"https://www.permanentstyle.com/2012/12/how-a-felt-hat-is-made-christys-factory-visit.html"},{"title":"Stetson hat factory (Dusty Old Thing)","url":"https://dustyoldthing.com/stetson-hat-factory"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ferrite","name":"Ferrite","kind":"material","category":"electronics","title":"How ferrite is made","url":"https://assemblyline.org/make/ferrite","stations":6,"upstream":9,"downstream":3,"depth":4,"dek":"It is a magnetic ceramic made mostly of rust-like iron oxide, cheap enough to stick on your refrigerator.","answer":"Iron oxide mixed with zinc, manganese or strontium compounds is baked until the metals combine into a magnetic ceramic. The cooled product is milled very fine, pressed to shape, often in a magnetic field, and sintered again. Hard grades become permanent magnets, and soft grades become the cores inside phone chargers, since they barely conduct electricity.","aka":["ferrite core","ceramic magnet","ferrite magnet","strontium ferrite"],"inputs":["iron-ore","zinc-oxide","manganese-ore"],"uses":["headphones","phone-charger","loudspeaker"],"grounds":["iron-ore","manganese-ore","air","zinc-ore","sulfur","water"],"upstreamSlugs":["iron-ore","zinc-oxide","manganese-ore","zinc","air","zinc-ore","sulfuric-acid","sulfur","water"],"downstreamSlugs":["headphones","phone-charger","loudspeaker"],"steps":[{"name":"Blend the oxides","process":"mix","text":"Finely powdered iron oxide is mixed with the other metals. Transformer cores use nickel, zinc or manganese compounds, and permanent magnets use barium or strontium carbonate.","inputs":["iron-ore","zinc-oxide","manganese-ore"]},{"name":"Calcine into ferrite","process":"fire","text":"Heat drives off carbon dioxide from any carbonates, and the oxides combine into the new crystal structure. Co-precipitation from solution is the other route, ending in the same calcining step.","inputs":[]},{"name":"Mill very fine","process":"grind","text":"The cooled solid is milled to particles smaller than 2 μm. At that size each particle holds a single magnetic domain.","inputs":[]},{"name":"Press in a field","process":"press","text":"Powder is pressed into a core or magnet shape and dried. For permanent magnets an external magnetic field during pressing lines the particles up in one preferred direction.","inputs":[]},{"name":"Sinter again","process":"fire","text":"A second firing turns the pressed powder into a hard, dense ceramic body. Particles fuse together while the shape set in the press holds.","inputs":[]},{"name":"Grind and magnetize","process":"grind","text":"Parts are ground to final size. Soft cores are finished at this point, and hard magnets then get a strong field that gives them their permanent charge.","inputs":[]}],"facts":["Yogoro Kato and Takeshi Takei of the Tokyo Institute of Technology made the first ferrite compounds in 1930.","Most ferrites do not conduct electricity, which stops eddy currents from wasting energy in transformer cores.","Refrigerator magnets and many loudspeaker magnets are hard ferrite."],"where":[],"whereNote":null,"sources":[{"title":"Ferrite (magnet)","url":"https://en.wikipedia.org/wiki/Ferrite_(magnet)"},{"title":"Magnetic core","url":"https://en.wikipedia.org/wiki/Magnetic_core"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"fertilizer","name":"Fertilizer","kind":"product","category":"chemicals","title":"How fertilizer is made","url":"https://assemblyline.org/make/fertilizer","stations":7,"upstream":16,"downstream":0,"depth":4,"dek":"Synthetic nitrogen fertilizer feeds about half the people on Earth, and it starts with air and natural gas.","answer":"Fertilizer is made by turning plant nutrients into forms that dissolve in soil water. Ammonia from air and natural gas becomes urea or ammonium nitrate. Phosphate rock is dissolved in sulfuric acid, and potash is mined and washed. The nutrients are blended, formed into granules and bagged.","aka":["plant food","NPK","urea","ammonium nitrate"],"inputs":["ammonia","nitric-acid","carbon-dioxide","phosphate-rock","sulfuric-acid","potash"],"uses":[],"grounds":["phosphate-rock","potash","natural-gas","water","air","corn","limestone","sulfur","sugarcane","sugar-beet"],"upstreamSlugs":["ammonia","nitric-acid","carbon-dioxide","phosphate-rock","sulfuric-acid","potash","natural-gas","water","air","corn","yeast","limestone","sulfur","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Make ammonia from air","process":"react","text":"Nitrogen is the nutrient plants use most, and the Haber process captures it from the air as ammonia. This is the starting block for most nitrogen fertilizers.","inputs":["ammonia"]},{"name":"Turn ammonia into solids","process":"react","text":"Ammonia reacts with carbon dioxide to make urea, or with nitric acid to make ammonium nitrate. Each is concentrated to a hot liquid and then solidified.","inputs":["nitric-acid","ammonia","carbon-dioxide"]},{"name":"Dissolve the phosphate rock","process":"react","text":"Phosphate rock is insoluble, so crops cannot use it directly. Sulfuric acid breaks it down into forms that dissolve in water.","inputs":["phosphate-rock","sulfuric-acid"]},{"name":"Wash and sort the potash","process":"separate","text":"Mined potash ore is crushed, and its potassium salt is separated from clay and common salt by dissolving or floating it. It is then dried and screened.","inputs":["potash"]},{"name":"Blend the nutrients","process":"mix","text":"Nitrogen, phosphorus and potassium ingredients are measured into a mixer in the ratios printed on the bag. A fertilizer for lawns and one for corn use different recipes.","inputs":[]},{"name":"Form granules or prills","process":"mold","text":"Liquid urea is dropped from a tower and falls as tiny beads, called prills, that harden on the way down. Other plants tumble damp powder in a drum so it grows into granules.","inputs":[]},{"name":"Dry, coat and bag it","process":"package","text":"Granules are dried, screened and sometimes coated so they do not cake or dust. They are bagged or shipped loose.","inputs":[]}],"facts":["Nitrogen fertilizer use rose by 800% between 1961 and 2019.","Friedrich Wöhler made urea from inorganic starting materials in 1828, which showed that a substance from living things could be made without them.","In 2021, farmers used 195 million tonnes of nutrients in inorganic fertilizers, and 56% of that was nitrogen."],"where":[],"whereNote":null,"sources":[{"title":"Fertilizer","url":"https://en.wikipedia.org/wiki/Fertilizer"},{"title":"Urea","url":"https://en.wikipedia.org/wiki/Urea"},{"title":"Ammonium nitrate","url":"https://en.wikipedia.org/wiki/Ammonium_nitrate"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"fiberglass","name":"Fiberglass","kind":"material","category":"plastics","title":"How fiberglass is made","url":"https://assemblyline.org/make/fiberglass","stations":6,"upstream":16,"downstream":53,"depth":5,"dek":"Fiberglass is ordinary glass drawn into threads as fine as silk, then bundled and bonded in resin.","answer":"Fiberglass starts as molten glass made from sand, limestone and soda ash. The glass drips through a plate of tiny nozzles called a bushing and is stretched into fine filaments, which are coated with a protective size and gathered into strands. Strands are then woven, chopped or matted and bonded in resin.","aka":["glass fiber","glass-reinforced plastic","GRP"],"inputs":["silica-sand","limestone","soda-ash"],"uses":["printed-circuit-board","wind-turbine","surfboard","ski","snowboard","fishing-rod","kite","roof-shingle","vinyl-floor","canoe","sailboat","umbrella"],"grounds":["silica-sand","limestone","rock-salt","water","trona","natural-gas","air","corn","sugarcane","sugar-beet"],"upstreamSlugs":["silica-sand","limestone","soda-ash","rock-salt","water","ammonia","carbon-dioxide","lime","trona","natural-gas","air","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["printed-circuit-board","wind-turbine","surfboard","ski","snowboard","fishing-rod","kite","roof-shingle","vinyl-floor","canoe","sailboat","umbrella","hearing-aid","pacemaker","thermometer","led-bulb","ev-battery","smartphone","laptop","television","hard-drive","solid-state-drive","computer-keyboard","computer-mouse","microwave-oven","washing-machine","drone","satellite","car","electric-car","airbag","airplane","rocket","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","smoke-detector","smartwatch","wireless-earbuds","phone-charger","digital-camera","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","skyscraper"],"steps":[{"name":"Weigh and blend the batch","process":"mix","text":"Silica sand, limestone, soda ash and other minerals are measured by computer and blended. For the reinforcing grade called E-glass, boron compounds are included.","inputs":["silica-sand","limestone","soda-ash"]},{"name":"Melt it in the furnace","process":"melt","text":"The batch is melted into a glowing liquid in a large furnace. Glass has no true melting point, so it simply softens and flows as it gets hotter.","inputs":[]},{"name":"Feed it to the bushing","process":"cast","text":"Molten glass flows through channels to a small platinum alloy plate pierced with hundreds of nozzles. The bushing is the most important piece of the machine.","inputs":[]},{"name":"Stretch it into filaments","process":"draw","text":"Glass drips from each nozzle and is pulled by a fast-spinning winder into a fine thread. Quick cooling stops it from forming crystals.","inputs":[]},{"name":"Coat it with sizing","process":"coat","text":"A thin chemical coating called a size is applied to the filaments right after they form. It protects them from scratching one another and helps resin bond to them.","inputs":[]},{"name":"Gather, dry and wind","process":"dry","text":"Filaments are collected into strands and wound onto cakes, which are dried. Strands are later woven into cloth, chopped, or laid into mats.","inputs":[]}],"facts":["In 1893, Edward Drummond Libbey exhibited a dress woven with glass fibers that had the diameter and texture of silk.","Games Slayter of Owens-Illinois invented glass wool for insulation between 1932 and 1933.","The most common glass fiber is E-glass, an alumino-borosilicate glass with less than 1% alkali oxides."],"where":[],"whereNote":null,"sources":[{"title":"Glass fiber","url":"https://en.wikipedia.org/wiki/Glass_fiber"},{"title":"Glass-reinforced plastic","url":"https://en.wikipedia.org/wiki/Glass-reinforced_plastic"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"insulation","name":"Fiberglass insulation","kind":"product","category":"minerals","title":"How fiberglass insulation is made","url":"https://assemblyline.org/make/insulation","stations":6,"upstream":28,"downstream":1,"depth":8,"dek":"Fiberglass insulation is made like cotton candy, with molten glass flung through a spinning cup.","answer":"Fiberglass insulation starts as sand and recycled glass melted at about 1,450 °C. The molten glass is forced through the holes of a spinning metal cup, and centrifugal force pulls it into thin fibers. A binder resin glues the fibers into a mat, which is baked at around 200 °C, cut and rolled.","aka":["glass wool","fiberglass batts","pink insulation"],"inputs":["silica-sand","adhesive"],"uses":["dishwasher"],"grounds":["silica-sand","water","crude-oil","natural-gas","air","sulfur","rock-salt","coal"],"upstreamSlugs":["silica-sand","adhesive","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","naphtha","natural-gas","air","sulfur","benzene","rock-salt","toluene","coal"],"downstreamSlugs":["dishwasher"],"steps":[{"name":"Melt sand and scrap glass","process":"melt","text":"Natural sand and recycled glass are mixed and heated to 1,450 °C to make molten glass.","inputs":["silica-sand"],"spec":"1,450 °C"},{"name":"Fling it through a spinner","process":"spin","text":"Molten glass is forced into a rapidly spinning metal cup with small holes. Centrifugal force pulls the glass out through the holes as fibers, and they cool in the air.","inputs":[]},{"name":"Dab on the binder","process":"coat","text":"A drop of binder goes at each fiber crossing, so the fibers hold together and the mat has cohesion and mechanical strength.","inputs":["adhesive"]},{"name":"Bake the mat","process":"dry","text":"The fiber mat is heated to around 200 °C, which cures the resin binder.","inputs":[],"spec":"around 200 °C"},{"name":"Press it flat","process":"roll","text":"The mat is calendered, which means it is pressed between rollers, to give it strength and stability.","inputs":[]},{"name":"Cut, roll and pack","process":"package","text":"The mat is cut into batts or continuous blankets, packed in rolls or panels, and palletized.","inputs":[]}],"facts":["Games Slayter discovered mass production of glass strands in 1932 when he blew a jet of compressed air at a stream of molten glass.","Fiberglass insulates because it traps air in tiny pockets, and small gas cells stop heat from carrying by convection.","In 2011, the US National Toxicology Program removed bio-soluble glass wool used in building insulation from its Report on Carcinogens."],"where":[],"whereNote":null,"sources":[{"title":"Glass wool","url":"https://en.wikipedia.org/wiki/Glass_wool"},{"title":"Fiberglass","url":"https://en.wikipedia.org/wiki/Fiberglass"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"fire-extinguisher","name":"Fire extinguisher","kind":"product","category":"hardware","title":"How fire extinguishers are made","url":"https://assemblyline.org/make/fire-extinguisher","stations":8,"upstream":83,"downstream":0,"depth":10,"dek":"Captain Manby's portable extinguisher of 1816 was a copper vessel holding three gallons of pearl ash.","answer":"Water and powder extinguishers have a mild steel body that is deep drawn, with base and dome formed separately and welded on. Brass valves are forged and machined. A factory paints and labels the cylinder, fills it, seals it and pressurizes it with nitrogen plus helium. Helium serves as a tracer so a sealed chamber can detect leaks. CO2 models instead use a one-piece aluminum shell from cold impact extrusion.","aka":["fire extinguisher","dry chemical extinguisher"],"inputs":["sheet-steel","paint","brass","baking-soda","nitrogen","rubber"],"uses":[],"grounds":["water","trona","limestone","rock-salt","air","natural-latex","sulfur","zinc-ore","titanium-ore","iron-ore","copper-ore","lead-ore","tin-ore","crude-oil","coal","natural-gas","corn","dolomite","manganese-ore","bauxite","quartz","timber","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["sheet-steel","paint","brass","baking-soda","nitrogen","rubber","steel","zinc","water","titanium-dioxide","pigment","acrylic","tin-can","copper","lead","tin","aluminum","trona","limestone","ammonia","rock-salt","soda-ash","carbon-dioxide","air","natural-latex","synthetic-rubber","carbon-black","sulfur","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","sulfuric-acid","titanium-ore","chlorine","coke","iron-ore","propylene","methanol","tinplate","lacquer","ink","copper-ore","lead-ore","tin-ore","crude-oil","coal","petroleum-coke","alumina","natural-gas","corn","yeast","naphtha","benzene","ethylene","styrene","dolomite","silicon","propane","manganese-ore","ethanol","vegetable-oil","phenolic-resin","bauxite","caustic-soda","molasses","hydrogen","toluene","quartz","charcoal","timber","sugarcane","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Deep draw the body","process":"stamp","text":"Mild steel is drawn into the cylinder wall. CO2 bodies differ: a hydraulic ram presses an aluminum slug into a one-piece shell, which is heat treated for strength.","inputs":["sheet-steel"]},{"name":"Weld base and dome","process":"weld","text":"Base and dome are formed separately and welded to the drawn cylinder. Finished welds are visually checked for defects.","inputs":[]},{"name":"Paint and label","process":"coat","text":"The body is painted and labeled with its charge, fire rating, operating pictograms and a color band for the agent, as BS EN 3-7 requires.","inputs":["paint"]},{"name":"Forge the valve","process":"forge","text":"Hot brass bar stock is forged to the valve's shape, then machined to cut its openings and threads. A dip tube goes on to reach inside the body.","inputs":["brass"]},{"name":"Fill with the agent","process":"fill","text":"Powder is measured in through the neck and the valve assembly goes on, sealing the body.","inputs":["baking-soda"]},{"name":"Pressurize the cylinder","process":"fill","text":"A compressor charges the stored-pressure unit with 90% nitrogen and 10% helium. The helium is there as a tracer for the leak test.","inputs":["nitrogen"]},{"name":"Fit hose and nozzle","process":"assemble","text":"The hose joins the valve assembly with a nozzle at its far end, so the agent flows from dip tube through valve to the fire.","inputs":["rubber"]},{"name":"Check for leaks","process":"inspect","text":"A sealed chamber sniffs for leaks. Burst, discharge and gas tests run to BS EN 3-7, and 5% of finished units get a final inspection.","inputs":[]}],"facts":["Captain George William Manby demonstrated a portable pressurized extinguisher in 1816, a copper vessel with three gallons of pearl ash solution.","Walter Kidde Company developed the carbon dioxide extinguisher in 1924 because Bell Telephone needed an agent that does not conduct electricity.","The first fire extinguisher on record was patented in England in 1723 by the chemist Ambrose Godfrey."],"where":[],"whereNote":null,"sources":[{"title":"City Fire Protection: How is a fire extinguisher made?","url":"https://www.cityfire.co.uk/news/how-is-a-fire-extinguisher-made/"},{"title":"Fire extinguisher","url":"https://en.wikipedia.org/wiki/Fire_extinguisher"},{"title":"Deep drawing","url":"https://en.wikipedia.org/wiki/Deep_drawing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"fireworks","name":"Fireworks","kind":"product","category":"play","title":"How fireworks are made","url":"https://assemblyline.org/make/fireworks","stations":6,"upstream":64,"downstream":0,"depth":10,"dek":"On New Year's Eve, about 1,000 times more birds are in flight than on other nights, flushed up by fireworks.","answer":"Fireworks are built in licensed factories where each step is separated into small buildings. Workers make paper tubes and shells, load them with the colored and sound-making parts of a design, and add fuses. Finished products are dried, packed in strict limits and kept in approved stores. Only trained crews fire the big shells.","aka":["pyrotechnics","firecrackers","skyrockets"],"inputs":["paper","cardboard","charcoal","sulfur","thread","cardboard-box"],"uses":[],"grounds":["sulfur","water","kaolin","limestone","timber","rock-salt","air","crude-oil","soybeans","rapeseed","clay","titanium-ore","iron-ore","corn","sugarcane","natural-gas","coal","sugar-beet"],"upstreamSlugs":["paper","cardboard","charcoal","sulfur","thread","cardboard-box","wood-pulp","water","kaolin","limestone","adhesive","timber","polyester","ink","caustic-soda","lime","oxygen","hydrogen-peroxide","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","pet-plastic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","rock-salt","air","hydrogen","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","p-xylene","ethylene-glycol","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","coke","iron-ore","corn","sugarcane","yeast","natural-gas","naphtha","benzene","carbon-dioxide","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Roll the paper tubes","process":"assemble","text":"Casings are rolled from paper and cardboard and glued. Their length and thickness set the size of a shell or the number of shots in a cake.","inputs":["paper","cardboard"]},{"name":"Prepare the effect parts","process":"mix","text":"In small, separated rooms, trained workers prepare the pellets that give each firework its colors and effects. Rooms are kept clean, damp and free of sparks, and only a limited number of people are allowed in.","inputs":[]},{"name":"Load the casings","process":"assemble","text":"Casings are charged with black powder, made from charcoal, sulfur and an oxidizer, that supplies the lift and the burst, along with the pellets for the effect. A shell designed to burst into a flower is loaded differently from one that cracks loudly.","inputs":["charcoal","sulfur"]},{"name":"Wrap and fit the fuses","process":"assemble","text":"Shells are wrapped with strong paper or string, and fuses are attached to start the sequence at the right instant.","inputs":["paper","thread"]},{"name":"Dry the finished pieces","process":"dry","text":"Completed items dry in the sun or in a heated room, away from fire sources, until they are ready for testing.","inputs":[]},{"name":"Test samples and pack","process":"inspect","text":"Samples from each batch are fired in a test area, and approved stock is packed in small quantities for safe transport.","inputs":["cardboard-box"]}],"facts":["During the Song dynasty, people made the first firecrackers from tubes of rolled paper filled with gunpowder, after earlier ones used exploding bamboo.","A single firework cake can contain more than 1,000 shots."],"where":[],"whereNote":null,"sources":[{"title":"Fireworks","url":"https://en.wikipedia.org/wiki/Fireworks"},{"title":"Pyrotechnics","url":"https://en.wikipedia.org/wiki/Pyrotechnics"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"fish-sticks","name":"Fish sticks","kind":"product","category":"food","title":"How fish sticks are made","url":"https://assemblyline.org/make/fish-sticks","stations":6,"upstream":69,"downstream":0,"depth":10,"dek":"Fish sticks are sawn from frozen blocks of fish that come in one standard size.","answer":"Whitefish such as cod, hake, haddock or pollock is formed into standard frozen blocks. The blocks are sliced into rectangular sticks, coated in batter or breadcrumbs and frozen again. The sticks are bagged and boxed for the freezer aisle, then baked, grilled or fried at home.","aka":["fish fingers","breaded fish"],"inputs":["whitefish","flour","water","bread","vegetable-oil","cardboard-box"],"uses":[],"grounds":["whitefish","water","wheat","soybeans","rapeseed","clay","air","rock-salt","seawater","crude-oil","corn","natural-gas","sugarcane","sugar-beet","timber","titanium-ore","iron-ore","sulfur","limestone","coal"],"upstreamSlugs":["whitefish","flour","water","bread","vegetable-oil","cardboard-box","wheat","vitamin-c","yeast","table-salt","soybeans","rapeseed","hexane","clay","cardboard","ink","adhesive","corn-starch","hydrogen","air","sugar","plastic-bottle","molasses","rock-salt","seawater","crude-oil","wood-pulp","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","corn","natural-gas","sugarcane","sugar-beet","lime","pet-plastic","timber","caustic-soda","oxygen","hydrogen-peroxide","phenol","formaldehyde","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","ethylene","propylene","ammonia","methanol","acetone","nitric-acid","limestone","p-xylene","ethylene-glycol","benzene","coal","naphtha","carbon-dioxide","toluene"],"downstreamSlugs":[],"steps":[{"name":"Freeze fish into blocks","process":"chill","text":"Fish pieces, often minced cod or pollock in big plants, are frozen into a large standard block. A 1952 General Foods patent describes this as the starting point, and factories still work the same way.","inputs":["whitefish"],"spec":"7.5 kg blocks"},{"name":"Saw into sticks","process":"cut","text":"Saws cut each block down to consumer-size rectangles while the fish is still frozen hard, which keeps the shape consistent.","inputs":[]},{"name":"Dip in batter","process":"coat","text":"The frozen sticks are seasoned and run through a batter, which gives the crumbs something to grab.","inputs":["flour","water"]},{"name":"Coat with crumbs","process":"coat","text":"A layer of breading sticks to the wet batter and gives the crust its even look.","inputs":["bread"]},{"name":"Fry to set the crust","process":"cook","text":"The coated sticks go through a fryer that cooks them at least partly and fixes the coating, with the fish staying frozen inside.","inputs":["vegetable-oil"]},{"name":"Refreeze and pack","process":"package","text":"The fried sticks are frozen again and packed in bags and boxes for the freezer aisle.","inputs":["cardboard-box"]}],"facts":["The commercial fish stick was released under the Birds Eye label in 1953.","Birds Eye test-marketed herring fish fingers in Britain, but shoppers overwhelmingly preferred cod.","The snack was nearly called Battered Cod Pieces until a poll of Birds Eye workers chose Fish Fingers."],"where":[],"whereNote":null,"sources":[{"title":"Quartz: The history of fish sticks","url":"https://qz.com/2118460/the-history-of-fish-sticks"},{"title":"Foodbeast: Watch how frozen fish sticks are made","url":"https://www.foodbeast.com/news/fish-sticks-made"},{"title":"Fish stick","url":"https://en.wikipedia.org/wiki/Fish_stick"},{"title":"Fish processing","url":"https://en.wikipedia.org/wiki/Fish_processing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"fishing-rod","name":"Fishing rod","kind":"product","category":"play","title":"How fishing rods are made","url":"https://assemblyline.org/make/fishing-rod","stations":8,"upstream":81,"downstream":0,"depth":10,"dek":"A graphite rod is rolled like a rug around a steel taper, then baked until the resin melts and sets.","answer":"Most modern fishing rods begin as a hollow blank. Sheets of carbon fiber or fiberglass, already soaked in resin, are cut to a taper pattern, rolled around a tapered steel mandrel, wrapped tight in tape and baked. After the mandrel is pulled, the blank is sanded and coated. Guides, a cork grip and a reel seat are then fixed on.","aka":["fishing pole","rod blank","fly rod"],"inputs":["carbon-fiber","fiberglass","epoxy","paint","cork-bark","thread","adhesive","steel"],"uses":[],"grounds":["cork-bark","air","silica-sand","limestone","water","crude-oil","natural-gas","rock-salt","trona","titanium-ore","iron-ore","sulfur","dolomite","manganese-ore","corn","coal","quartz","timber","tin-ore","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["carbon-fiber","fiberglass","epoxy","paint","cork-bark","thread","adhesive","steel","propylene","ammonia","air","silica-sand","limestone","soda-ash","phenol","acetone","chlorine","caustic-soda","water","titanium-dioxide","pigment","acrylic","tin-can","polyester","polyethylene","polyurethane","paraffin-wax","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","naphtha","crude-oil","natural-gas","rock-salt","carbon-dioxide","trona","benzene","sulfuric-acid","titanium-ore","coke","iron-ore","carbon-black","sulfur","methanol","tinplate","lacquer","ink","pet-plastic","ethylene","nitric-acid","hydrogen","dolomite","silicon","propane","manganese-ore","corn","yeast","toluene","coal","tin","ethanol","vegetable-oil","phenolic-resin","p-xylene","ethylene-glycol","quartz","charcoal","timber","molasses","tin-ore","sugarcane","soybeans","rapeseed","hexane","clay","formaldehyde","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the flags","process":"cut","text":"Rolls of prepreg, graphite or fiberglass already carrying resin, are kept cold so they do not cure early. Pieces called flags are cut from them, with angles worked out so the finished rod bends the right way. Machines now cut them to precise patterns, where once it was done by hand.","inputs":["carbon-fiber","fiberglass","epoxy"]},{"name":"Tack a flag to the mandrel","process":"weld","text":"A hot iron sticks the edge of the flag to a long tapered steel rod. That rod, the mandrel, sets the blank's inside diameter and taper.","inputs":[]},{"name":"Roll the layers on","process":"roll","text":"A machine with two heated plates slides in opposite directions and rolls the material onto the mandrel. Layers can be laid at 0, 45 or 90 degrees to strengthen the blank in different directions.","inputs":[]},{"name":"Bind it in shrink tape","process":"press","text":"The roll is wrapped tightly in cellophane or shrink tape, which squeezes out trapped air and holds the layers down so the resin flows evenly.","inputs":[]},{"name":"Bake in a tall oven","process":"dry","text":"Wrapped mandrels hang in racks inside curing ovens for several hours. The resin melts, flows and hardens, locking the fibers together. Some ovens are tall enough for a 14-foot one-piece blank.","inputs":[]},{"name":"Strip the tape and mandrel","process":"separate","text":"After cooling, a machine pulls the tape off the blank. The steel mandrel is then pulled out, easier because release agents were applied before rolling. What is left is a hollow tube.","inputs":[]},{"name":"Sand and dip-coat","process":"coat","text":"The blank is sanded smooth and to its exact diameter, then painted or clear-coated. One maker dips blanks into a pipe that goes 11 feet into the floor and hangs them to dry.","inputs":["paint"]},{"name":"Fix on grip and guides","process":"assemble","text":"A rod builder glues on a cork grip and a reel seat, and wraps thread around the legs of the guides to hold them. Guides are steel or titanium with ceramic or metal inserts that the line slides through.","inputs":["cork-bark","thread","adhesive","steel"]}],"facts":["Before graphite, anglers used bamboo rods made of several strips of cane, milled to shape and glued into a light, hexagonal rod.","A rod's action describes how fast it springs back after bending, not how far it bends.","A \"fast\" fiberglass rod can have a slower action than a \"medium\" bamboo rod, because makers label action by their own rules."],"where":[],"whereNote":null,"sources":[{"title":"How Graphite Rod Blanks Are Made","url":"https://mudhole.com/blogs/product-reviews/how-graphite-rod-blanks-are-made"},{"title":"Fishing rod","url":"https://en.wikipedia.org/wiki/Fishing_rod"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"flag","name":"Flag","kind":"product","category":"textiles","title":"How flags are made","url":"https://assemblyline.org/make/flag","stations":6,"upstream":63,"downstream":0,"depth":8,"dek":"Many flags are dyed all the way through, so the back is the mirror image of the front.","answer":"Most flags are polyester or nylon cloth that is printed or dyed with the design, cut to size and stitched at the edges. Many are dyed through so the reverse is a mirror image. Better American flags have embroidered stars and sewn stripes instead. A canvas header with grommets goes on the pole side.","aka":["banner","national flag","pennant"],"inputs":["nylon","polyester","ink","thread","brass"],"uses":[],"grounds":["water","air","natural-gas","soybeans","rapeseed","clay","crude-oil","titanium-ore","iron-ore","sulfur","corn","sugarcane","copper-ore","zinc-ore","lead-ore","tin-ore","coal","rock-salt","bauxite","limestone","sugar-beet"],"upstreamSlugs":["nylon","polyester","ink","thread","brass","benzene","nitric-acid","ammonia","pet-plastic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","copper","zinc","lead","tin","aluminum","naphtha","hydrogen","toluene","air","natural-gas","p-xylene","ethylene","ethylene-glycol","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","copper-ore","zinc-ore","lead-ore","tin-ore","coal","petroleum-coke","alumina","carbon-dioxide","propylene","methanol","rock-salt","molasses","bauxite","caustic-soda","lime","limestone","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Weave the flag cloth","process":"weave","text":"Nylon or polyester yarn is woven into a light, strong cloth. A flag has to survive wind, sun and rain, so the cloth is tightly woven and tough.","inputs":["nylon","polyester"]},{"name":"Print or dye the design","process":"print","text":"The design is printed onto the cloth with dyes, or screens lay down each color in turn. A through-and-through print soaks the dye in so the reverse side is a mirror image. Premium American flags skip the printing: machines embroider each star and the stripes are sewn from dyed strips.","inputs":["ink"]},{"name":"Fix the color","process":"heat-treat","text":"Heat sets the dye into the fibers so it stays in sunlight and washing. Printed rolls are steamed or run through a hot press.","inputs":[]},{"name":"Cut the flag to size","process":"cut","text":"Rolls are cut into flags of a set ratio, such as two units tall to three wide. A little extra cloth is left on each edge for hems.","inputs":[]},{"name":"Stitch the fly edge","process":"sew","text":"The free edge of the flag is hemmed with several rows of stitching, using lockstitch seams where two threads interlock. Stress points such as the corners get extra reinforcement, because this is the edge that whips in the wind.","inputs":["thread"]},{"name":"Attach the hoist","process":"assemble","text":"A double or triple thickness of canvas is sewn along the side that meets the pole, spreading the pull of the wind. Brass grommets or a pole sleeve are added so the flag can be tied or slid onto a pole.","inputs":["brass","thread"]}],"facts":["Motorized sewing machines in the 1860s cut the time to sew a flag at Annin from a day to an hour.","Annin sold 1.5 million flags during the American Civil War."],"where":[],"whereNote":null,"sources":[{"title":"Flag","url":"https://en.wikipedia.org/wiki/Flag"},{"title":"From cotton to nylon: how American flags are made (Bags of Flags)","url":"https://bagsofflags.com/blogs/news/from-cotton-to-nylon-how-american-flags-are-made"},{"title":"Broad Stripes, Bright Stars (American Legion)","url":"https://www.legion.org/magazine/227264/broad-stripes-bright-stars"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"flax","name":"Flax","kind":"raw","category":"farm","title":"How flax is grown and harvested","url":"https://assemblyline.org/make/flax","stations":3,"upstream":0,"downstream":5,"depth":0,"dek":"Flax for linen is pulled up by the roots, then left in dew or water until the stalks rot away from the fibers.","answer":"Flax is sown in cool temperate fields and grows for about 100 days. For linen it is pulled with its roots when the stalk bases turn yellow, which keeps the fibers as long as possible. The bundles are then retted, soaked or left in dew, until microbes rot the woody core and loosen the fibers.","aka":["linen flax","flax straw","linseed plant"],"inputs":[],"uses":["kitchen-sponge","linseed-oil","banknote","linen"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["kitchen-sponge","linseed-oil","banknote","linen","stained-glass"],"steps":[{"name":"Sow in deep loam","process":"grow","text":"Flax does best in deep loams rich in organic matter and fails in heavy clay or gravel. It needs few fertilizers or pesticides and reaches about 3 feet tall.","inputs":[]},{"name":"Pull it before it browns","process":"harvest","text":"The crop is ready after about 100 days, a month after flowering, when the bases of the plants start to turn yellow. Green plants have underdeveloped fiber, and once the stalks turn brown the fiber starts to degrade, so timing decides the quality.","inputs":[],"spec":"about 100 days"},{"name":"Ret the stalks","process":"dry","text":"Bundles of stalks lie in a pond, stream or tank, or spread in a field under dew, until microbes break down the glue holding fiber to the woody core. Field retting takes a month or more but gives the best fiber, and warm tank water at 27 °C can finish in 4 or 5 days.","inputs":[],"spec":"a month or more in the field"}],"facts":["Spun, dyed and knotted wild flax fibers found in a cave in Georgia date to about 30,000 years ago.","France produced 75% of the world's raw or retted flax in 2022."],"where":[{"place":"France","share":"75% of world output"}],"whereNote":"2022, share of 875,995 tonnes of raw or retted flax produced worldwide.","sources":[{"title":"Flax","url":"https://en.wikipedia.org/wiki/Flax"},{"title":"Linen","url":"https://en.wikipedia.org/wiki/Linen"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"flip-flops","name":"Flip-flops","kind":"product","category":"textiles","title":"How flip-flops are made","url":"https://assemblyline.org/make/flip-flops","stations":6,"upstream":52,"downstream":0,"depth":8,"dek":"Thong sandals go back thousands of years, and a modern pair can come out of a mold that works like a waffle iron.","answer":"Modern flip-flops are made by molding or cutting a flat sole from foam rubber or EVA plastic. In one route, pellets are melted and squirted into a hinged metal mold that shapes one shoe at a time. In another, soles are stamped out of sheets. A Y-shaped strap is then pushed through holes and locked from underneath.","aka":["thongs","jandals","thong sandals"],"inputs":["synthetic-rubber","polyethylene","pvc","ink","adhesive"],"uses":[],"grounds":["water","crude-oil","natural-gas","rock-salt","iron-ore","sulfur","air","soybeans","rapeseed","clay","titanium-ore","corn","sugarcane","coal","sugar-beet"],"upstreamSlugs":["synthetic-rubber","polyethylene","pvc","ink","adhesive","naphtha","benzene","ethylene","styrene","water","chlorine","pigment","plasticizer","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","ethanol","acrylic","epoxy","polyurethane","paraffin-wax","crude-oil","hydrogen","toluene","natural-gas","rock-salt","sulfuric-acid","iron-ore","sulfur","air","propylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","titanium-ore","coke","oxygen","corn","sugarcane","yeast","ammonia","methanol","acetone","caustic-soda","nitric-acid","coal","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mix the foam compound","process":"mix","text":"Rubber or plastic pellets are mixed with a foaming agent and color, then heated until the batch is a soft, uniform dough. It is rolled into sheets or fed into an injection machine.","inputs":["synthetic-rubber","polyethylene"]},{"name":"Form the soles","process":"mold","text":"In the injection route, a machine melts the pellets and squirts them into a hinged metal mold that makes one shoe per fill, and a worker trims the flash. In the sheet route, hydraulic presses mold the foam and a die stamps out foot shapes.","inputs":[]},{"name":"Punch the strap holes","process":"stamp","text":"A punch cuts three holes in the sole, one between the toes and one on each side of the foot. The thong and the arms of the strap anchor here.","inputs":[]},{"name":"Cut and print the strap","process":"print","text":"Straps are cut from soft rubber, PVC or fabric. They are printed with color or logos, and each end is fitted with a plug or a pin.","inputs":["pvc","ink"]},{"name":"Lock the strap in","process":"assemble","text":"The strap's pins are pushed through the three holes and secured underneath by a cap or a glued insole. The strap then sits snug against the sole.","inputs":["adhesive"]},{"name":"Regrind and pack","process":"package","text":"Trimmed scrap goes back to be reground and molded again. Pairs are matched and checked, and the flip-flops are bundled for shipping.","inputs":[]}],"facts":["Flip-flops are called thongs in Australia, jandals in New Zealand and plakkies in South Africa.","Thong sandals appear in Egyptian murals dating back to about 4000 BC.","At the Okabashi factory in Georgia, a pair of flip-flops takes about an hour from start to finish."],"where":[],"whereNote":null,"sources":[{"title":"Flip-flops","url":"https://en.wikipedia.org/wiki/Flip-flops"},{"title":"How flip-flops are made (Atlanta Journal-Constitution)","url":"https://www.ajc.com/news/local/how-flip-flops-are-made/nOeDgwqoiv1x2DetbOnd6L/"},{"title":"Flip-flop manufacturing (Sharda Associates)","url":"https://shardaassociates.in/pr-samples/flip-flop-manufacturing/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"flour","name":"Flour","kind":"material","category":"food","title":"How flour is made","url":"https://assemblyline.org/make/flour","stations":7,"upstream":24,"downstream":17,"depth":8,"dek":"A wheat kernel is cracked open between rollers and sifted again and again until only its white heart is left.","answer":"Wheat is cleaned, dampened and run through a series of roller mills. Each pass cracks the kernel a little more, and sifters pull off the bran and germ while the starchy center is ground finer and finer. The white endosperm powder is blended to a target protein level, sometimes bleached or matured, and bagged.","aka":["wheat flour","all-purpose flour","plain flour"],"inputs":["wheat","water","vitamin-c"],"uses":["bread","instant-noodles","tortilla","croissant","donut","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","fish-sticks","modeling-clay","licorice","cake-mix"],"grounds":["wheat","water","air","corn","natural-gas","sugarcane","sugar-beet","limestone","crude-oil"],"upstreamSlugs":["wheat","water","vitamin-c","corn-starch","hydrogen","air","sugar","plastic-bottle","corn","natural-gas","sugarcane","sugar-beet","lime","pet-plastic","limestone","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","crude-oil","yeast","molasses"],"downstreamSlugs":["bread","instant-noodles","tortilla","croissant","donut","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","fish-sticks","modeling-clay","licorice","cake-mix"],"steps":[{"name":"Scour out stones and chaff","process":"separate","text":"Incoming grain passes over screens, through air streams and past magnets that pull out stones, straw, seeds of other plants and stray metal. Every kernel that reaches the rollers has to be clean, because grit would wear the rolls and show up in the bread.","inputs":["wheat"]},{"name":"Dampen the kernels","process":"wash","text":"The wheat rests in bins after a measured dose of water. Moisture toughens the bran so it peels off in big flakes instead of shattering into specks, and it softens the starchy middle so it grinds cleanly.","inputs":["water"]},{"name":"Crack it between rollers","process":"crush","text":"Pairs of corrugated steel rolls turning at different speeds split each kernel open and scrape the endosperm off the bran. This is the first of several passes. Roller mills replaced stone grist mills in the 19th century.","inputs":[]},{"name":"Sift the fractions","process":"separate","text":"A plansifter, a vibrating box of stacked sieves that get finer toward the bottom, sorts the broken stock. Flour falls through, while bran and coarse pieces ride over the end and go to the next pair of rolls.","inputs":[]},{"name":"Reduce the white granules","process":"grind","text":"Smooth rolls grind the endosperm granules to powder, and each pass is sifted again. A mill may repeat the grind and sift cycle many times, and each cycle yields a stream of flour with slightly different protein and ash content.","inputs":[]},{"name":"Blend to specification","process":"mix","text":"Streams from different parts of the mill are blended to hit a protein target, because higher protein gives stronger, chewier dough and lower protein gives a softer, more tender crumb. A small dose of ascorbic acid is often added as a maturing agent that strengthens gluten.","inputs":["vitamin-c"]},{"name":"Bag it or blow it into silos","process":"package","text":"Finished flour is checked for moisture and protein, then packed in sacks or pumped by air into bulk trucks for industrial bakeries.","inputs":[]}],"facts":["Archaeologists have found evidence that people were making cereal flour over 32,000 years ago.","England's 1086 Domesday survey counted 5,624 water-powered flour mills, about one for every 300 inhabitants.","The first rolls in a flour mill are fluted and set to open each kernel as gently as possible, so the bran stays in big flakes."],"where":[],"whereNote":null,"sources":[{"title":"Flour","url":"https://en.wikipedia.org/wiki/Flour"},{"title":"Gristmill","url":"https://en.wikipedia.org/wiki/Flour_milling"},{"title":"The advent of modern milling","url":"https://millsarchive.org/2017/09/25/the-advent-of-modern-milling/20/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"fluorspar","name":"Fluorspar","kind":"raw","category":"ground","title":"How fluorspar is mined","url":"https://assemblyline.org/make/fluorspar","stations":3,"upstream":0,"downstream":8,"depth":0,"dek":"Fluorspar helps steelmakers by making molten slag runny. The name literally means to flow.","answer":"Fluorspar is calcium fluoride, mined from veins and pegmatites. The purest grades supply fluoride for hydrofluoric acid. Lower grades go into steel smelting as a flux that thins the slag. China leads world output at about 3 million tonnes a year, per figures for 2010.","aka":["fluorite","calcium fluoride","blue john"],"inputs":[],"uses":["ptfe","refrigerant"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["ptfe","refrigerant","razor-blade","nonstick-pan","raincoat","refrigerator","air-conditioner","asthma-inhaler"],"steps":[{"name":"Dig out the veins","process":"mine","text":"Fluorite forms late in crystallizing rock, often as veins through limestone with galena and quartz. Miners follow those veins underground or open them up at the surface.","inputs":[]},{"name":"Crush the vein rock","process":"crush","text":"Ore is crushed to free the fluorspar from lead ore, quartz and calcite. The Mohs hardness scale defines fluorite as 4.","inputs":[]},{"name":"Float and grade the concentrate","process":"separate","text":"Froth flotation lifts the fluorite away from the waste minerals. The purest fluorspar goes to chemical plants as the source of fluoride, while less pure grades are sold to steelmakers as a flux, and some becomes glass and enamel.","inputs":[]}],"facts":["Fluorite gave its name to fluorescence in 1852 and to the element fluorine.","The largest documented single fluorite crystal was a cube 2.12 meters across, weighing about 16 tonnes.","Pliny the Elder described carved fluorite as a precious stone that Romans prized."],"where":[{"place":"China","share":"about 3 million tonnes a year"},{"place":"Mexico","share":"1.0 million tonnes"},{"place":"Mongolia","share":"0.45 million tonnes"},{"place":"Russia","share":"0.22 million tonnes"},{"place":"South Africa","share":"0.13 million tonnes"}],"whereNote":"2010 annual production in million tonnes (Wikipedia).","sources":[{"title":"Fluorite","url":"https://en.wikipedia.org/wiki/Fluorite"},{"title":"Hydrofluoric acid","url":"https://en.wikipedia.org/wiki/Hydrofluoric_acid"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"flute","name":"Flute","kind":"product","category":"play","title":"How flutes are made","url":"https://assemblyline.org/make/flute","stations":9,"upstream":23,"downstream":0,"depth":5,"dek":"A flute's tone holes are either pulled up out of the tube wall or soldered on one at a time by hand.","answer":"Most modern concert flutes are metal, and student models are often silver-plated nickel silver. Makers draw tubing for the body, then draw or solder on the tone holes. Ribs and posts go on, and a separate team builds the key mechanism around them. The headjoint is cut by hand, and pads and corks are fitted before play-testing.","aka":["concert flute","transverse flute","western flute"],"inputs":["copper","nickel","zinc","solder","silver","cork-bark"],"uses":[],"grounds":["cork-bark","copper-ore","water","air","nickel-ore","zinc-ore","silver-ore","lead-ore","sulfur","tin-ore","limestone","coal"],"upstreamSlugs":["copper","nickel","zinc","solder","silver","cork-bark","copper-ore","water","oxygen","air","sulfuric-acid","nickel-ore","zinc-ore","tin","lead","silver-ore","lead-ore","lime","sulfur","tin-ore","coke","limestone","coal"],"downstreamSlugs":[],"steps":[{"name":"Alloy the tubing metal","process":"melt","text":"Student flutes are commonly nickel silver, an alloy of copper, nickel and zinc that contains no silver at all. Better flutes use sterling silver, and gold and platinum are used too.","inputs":["copper","nickel","zinc"]},{"name":"Draw the body tube","process":"draw","text":"The metal is formed into a tube. The flute is, in its most basic form, an open tube that the player blows across.","inputs":[]},{"name":"Add the tone holes","process":"draw","text":"Tone holes are either drawn up out of the tube wall or made separately and soldered on, each one fitted to the tube by hand. Their size and position decide which pitch each fingering gives.","inputs":["solder"]},{"name":"Solder on ribs and posts","process":"weld","text":"Ribs and posts go onto the body, followed by a barrel, a foot joint box and end rings. They carry the mechanism, so the body has to pass inspection before moving on.","inputs":["solder"]},{"name":"Build the key mechanism","process":"assemble","text":"Stringing is the trade's word for this. Workers shape milled, cast and stamped pieces into keys, fitting each key together with the others.","inputs":[]},{"name":"Assemble and cut the headjoint","process":"assemble","text":"A wall and a lip plate are soldered onto a tube drawn to a precise taper. A headjoint cutter then shapes the opening with a few hand tools, and plays the result to check its tone.","inputs":["solder"]},{"name":"Plate and polish","process":"coat","text":"Many flutes, especially student models, are electroplated with silver. The plating is thin and wears away easily. Body and mechanism are polished before padding.","inputs":["silver"]},{"name":"Seat pads and corks","process":"assemble","text":"Pads are fitted so each key can close its tone hole, and each cork is shaped by hand. At Powell the pads are adjusted to a half-thousandth of an inch.","inputs":["cork-bark"]},{"name":"Play-test and adjust","process":"inspect","text":"The instrument is played as a whole for the first time and goes through several rounds of testing, with spring tension adjusted for an even feel.","inputs":[]}],"facts":["In a blind listening test, professional flutists could not tell flutes of different metals apart.","Historically flutes were most commonly made of reed, bamboo or wood, and some were made of glass or bone."],"where":[],"whereNote":null,"sources":[{"title":"About us","url":"https://www.powellflutes.com/en/?p=227"},{"title":"Flute","url":"https://en.wikipedia.org/wiki/Flute"},{"title":"Finding the right flute","url":"https://flutesandflutists.com/finding-the-right-flute"},{"title":"Nickel silver","url":"https://en.wikipedia.org/wiki/Nickel_silver"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"frisbee","name":"Flying disc","kind":"product","category":"play","title":"How flying discs are made","url":"https://assemblyline.org/make/frisbee","stations":7,"upstream":40,"downstream":0,"depth":8,"dek":"A flying disc has a wing's cross-section, and most are molded in one shot from melted plastic pellets.","answer":"A flying disc is injection-molded. Plastic pellets are melted in a heated barrel and pushed by a screw into a closed metal mold shaped like the disc, then cooled until hard and released. Ultimate and classic discs are usually polyethylene, and disc golf discs are mostly polypropylene blends. A blade trims the rim and a hot stamp adds the logo.","aka":["frisbee","flying disc","ultimate disc","disc golf disc"],"inputs":["polyethylene","polypropylene","ink"],"uses":[],"grounds":["water","natural-gas","crude-oil","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","coal","sugar-beet"],"upstreamSlugs":["polyethylene","polypropylene","ink","ethylene","propylene","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","naphtha","natural-gas","crude-oil","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","air","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","hydrogen","benzene","methanol","rock-salt","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the metal mold","process":"machine","text":"A two-part mold of aluminum or steel is made for each design, with the inverse shape of the disc. Its cavity sets the airfoil: a rounded dome that lifts like a wing, and a rim.","inputs":[]},{"name":"Load the plastic pellets","process":"mix","text":"Millions of tiny pellets drop from a hopper, along with colored pellets. Classic and ultimate discs use polyethylene. Disc golf discs start from polypropylene, blended with a smaller share of other plastics to make them stiffer or gummier.","inputs":["polyethylene","polypropylene"]},{"name":"Melt in the barrel","process":"melt","text":"The pellets travel down a heated barrel and become a thick liquid.","inputs":[],"spec":"300 to 450 °F"},{"name":"Shoot it into the mold","process":"mold","text":"The mold is clamped shut under pressure. A screw or ram forces the molten plastic into the cavity, and more pressure holds it there until every curve fills.","inputs":[]},{"name":"Chill and eject","process":"chill","text":"Water or air channels in the mold cool the plastic until it holds its shape. The mold opens, and rods, a plate or a blast of air push the disc out.","inputs":[]},{"name":"Trim the rim","process":"cut","text":"A sharp blade runs around the rim to take off the flash, the thin excess left at the mold's seam. Makers differ here, and some discs keep a visibly uneven edge.","inputs":[]},{"name":"Hot-stamp the logo","process":"print","text":"Discs are checked for weight and size, then stamped. Heat from above transfers an adhesive design onto the flight plate, the flat area inside the rim.","inputs":["ink"]}],"facts":["The word Frisbee came from the Frisbie Pie Company, whose empty pie tins Yale students had tossed around.","Disc makers guard their plastic recipes closely, and small changes turn the same base from gummy to stiff.","Before the Pluto Platter, early flying discs were made of flexible polypropylene by a molder in Southern California."],"where":[],"whereNote":null,"sources":[{"title":"Frisbee","url":"https://en.wikipedia.org/wiki/Frisbee"},{"title":"How Discs Are Made","url":"https://roguediscs.com/blog/how-discs-are-made"},{"title":"How are discs for disc golf made?","url":"https://flexlinediscs.com/blogs/news/how-are-discs-for-disc-golf-made"},{"title":"How Are Disc Golf Discs Made","url":"https://discgolfnow.com/how-are-disc-golf-discs-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"foam-cup","name":"Foam cup","kind":"product","category":"plastics","title":"How foam cups are made","url":"https://assemblyline.org/make/foam-cup","stations":5,"upstream":12,"downstream":0,"depth":7,"dek":"A foam cup is about 95 percent air, held in place by plastic bubbles that were puffed up with steam.","answer":"Tiny polystyrene beads contain a gas called pentane. Steam makes the gas expand, puffing each bead up like popcorn. The puffed beads rest for a while, then go into a cup-shaped mold where more steam melts their skins together. The mold is cooled so the cup hardens, and then the cup is ejected.","aka":["styrofoam cup","polystyrene cup","EPS cup"],"inputs":["polystyrene","pentane"],"uses":[],"grounds":["natural-gas","crude-oil","water","coal"],"upstreamSlugs":["polystyrene","pentane","naphtha","ethylene","benzene","styrene","natural-gas","crude-oil","water","hydrogen","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Puff the beads with steam","process":"blow","text":"Polystyrene beads with pentane trapped inside meet steam in a pre-expander. The heat softens the plastic while the pentane turns to gas and swells each bead into a closed-cell foam sphere.","inputs":["polystyrene","pentane"]},{"name":"Let the beads rest","process":"dry","text":"The puffed beads sit in breathable bags or silos while air seeps into them and replaces some of the pentane. This keeps them from shrinking in the mold.","inputs":[]},{"name":"Fill the cup mold","process":"mold","text":"Beads are blown into an aluminum mold shaped like the cup. How densely they are packed sets how stiff the wall will be.","inputs":[]},{"name":"Fuse them with steam","process":"mold","text":"More steam softens the beads so they swell slightly and weld into one piece that fills the cavity.","inputs":[]},{"name":"Cool and eject","process":"chill","text":"The mold is cooled with water spray or vacuum so the plastic stiffens before it leaves the cavity. A cup that comes out too warm swells and deforms.","inputs":[]}],"facts":["Foam used in cups and coolers is typically 95 to 98 percent air.","Styrofoam is a trademark for a blue extruded building insulation, not for the white beaded foam in disposable cups."],"where":[],"whereNote":null,"sources":[{"title":"How to Make Styrofoam? From Polystyrene Beads to Foam","url":"https://epsole.com/how-to-make-styrofoam"},{"title":"Method for producing seamless foam plastic cups from expandable sidewall blanks","url":"https://patents.google.com/patent/US4060577"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"formaldehyde","name":"Formaldehyde","kind":"material","category":"chemicals","title":"How formaldehyde is made","url":"https://assemblyline.org/make/formaldehyde","stations":5,"upstream":4,"downstream":179,"depth":2,"dek":"Its discoverer was trying to make something else, and he got its formula wrong in his own paper.","answer":"Almost all of it starts as methanol vapor. Mixed with air and passed over a hot metal or metal oxide catalyst, the methanol loses hydrogen and becomes a pungent gas. The gas is dissolved in water straight away, since it would otherwise link up with itself, and tankers carry that solution to resin plants.","aka":["methanal","formalin"],"inputs":["methanol","air","water"],"uses":["super-glue","billiard-ball","spandex","melamine-resin","phenolic-resin","polyvinylpyrrolidone"],"grounds":["air","water","natural-gas"],"upstreamSlugs":["methanol","air","water","natural-gas"],"downstreamSlugs":["super-glue","billiard-ball","spandex","melamine-resin","phenolic-resin","polyvinylpyrrolidone","underwear","leggings","swimsuit","laminate-floor","ink","photoresist","brake-pad","hairspray","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","microchip","memory-chip","printed-circuit-board","lcd-screen","indium-tin-oxide","vacuum-cleaner","electric-kettle","cotton-candy","pillow","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","car","electric-car","soap","toothpaste","detergent","nitrile-glove","washing-machine","paperclip","donut","corn-flakes","popcorn","crayon","fireworks","candle","salsa","fish-sticks","zip-bag","blender","dishwasher","cotton-swab","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","hearing-aid","pacemaker","thermometer","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","airbag","rocket","smartwatch","phone-charger","usb-cable","digital-camera","e-reader","graphics-card","electric-toothbrush","led-bulb","ev-battery","hard-drive","wind-turbine","microwave-oven","airplane","locomotive","motorcycle","elevator","ceiling-fan","treadmill","pinball-machine","oled-screen","refrigerator","pencil","scissors","mirror","container-ship","shipping-container","bicycle","wooden-chair","water-bottle","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","subway-train","leather-belt","eyeglass-frame","toffee","skyscraper","padlock"],"steps":[{"name":"Vaporize the methanol","process":"cook","text":"Liquid methanol is boiled into vapor at the front of a closed plant. Oxidizing methane directly would be simpler on paper, but methanol reacts more readily, so methane stays out of the reactor.","inputs":["methanol"]},{"name":"Blend with air","process":"mix","text":"The vapor is mixed with air, which supplies the oxygen. Everything stays inside closed pipework on the way to the reactor.","inputs":["air"]},{"name":"Pass over the catalyst","process":"react","text":"The gas stream flows over a catalyst of silver metal or of iron and molybdenum oxides. Methanol is oxidized on the surface and leaves as formaldehyde gas.","inputs":[]},{"name":"Absorb into water","process":"mix","text":"Hot gas goes up through water, which takes it in. A saturated solution is about 37% by mass and is sold as formalin. The dissolved molecule becomes mostly a hydrate.","inputs":["water"]},{"name":"Stabilize and ship","process":"fill","text":"A little methanol stays in or is added to stop the solution from oxidizing and polymerizing. Tankers take it to plants making resins for particle board, coatings and plastics. It is a group 1 carcinogen, so handling is tightly controlled.","inputs":[]}],"facts":["Aleksandr Butlerov discovered formaldehyde in 1859 while trying to make something else, and his paper gave it the wrong formula.","Reactions in the upper atmosphere account for more than 80% of the formaldehyde in the environment.","Global production was estimated at 26 million tons per year in 2024."],"where":[],"whereNote":null,"sources":[{"title":"Formaldehyde","url":"https://en.wikipedia.org/wiki/Formaldehyde"},{"title":"Formaldehyde (Britannica)","url":"https://www.britannica.com/science/formaldehyde"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"foundation-makeup","name":"Foundation makeup","kind":"product","category":"body-health","title":"How foundation makeup is made","url":"https://assemblyline.org/make/foundation-makeup","stations":6,"upstream":57,"downstream":0,"depth":7,"dek":"The amount of pigment in a bottle decides coverage, from about 8 percent for sheer to up to 35 percent for full.","answer":"Foundation is pigment suspended in a base, most often an oil and water emulsion. Pigments such as titanium dioxide, iron oxides or mica are dispersed in the water phase. A warmed oil phase is stirred in, and the emulsion is cooled with agitation. Fragrance goes in during cooling. Sheer foundation has the least pigment and full coverage the most.","aka":["liquid foundation","face base","makeup base"],"inputs":["titanium-dioxide","zinc-oxide","mica","water","pigment","vegetable-oil","silicone","perfume","plastic-bottle"],"uses":[],"grounds":["mica","water","titanium-ore","air","iron-ore","sulfur","soybeans","rapeseed","clay","silica-sand","oranges","vanilla-pods","rock-salt","coal","zinc-ore","crude-oil","quartz","timber","natural-gas","corn","sugarcane","limestone","trona","sugar-beet"],"upstreamSlugs":["titanium-dioxide","zinc-oxide","mica","water","pigment","vegetable-oil","silicone","perfume","plastic-bottle","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","zinc","air","iron-ore","carbon-black","sulfur","soybeans","rapeseed","hexane","clay","silicon","methanol","hydrochloric-acid","silica-sand","oranges","vanilla-pods","ethanol","glass-bottle","pet-plastic","rock-salt","coal","zinc-ore","crude-oil","hydrogen","quartz","charcoal","timber","natural-gas","corn","sugarcane","yeast","ethylene","soda-ash","limestone","polyethylene","p-xylene","ethylene-glycol","molasses","naphtha","ammonia","carbon-dioxide","lime","trona","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Disperse the pigments","process":"grind","text":"Titanium dioxide, zinc oxide, mica and iron oxides are milled into the water phase until the particles break up and spread evenly. This pigment dispersion sets the color of the batch.","inputs":["titanium-dioxide","zinc-oxide","mica","water","pigment"]},{"name":"Warm the oil phase","process":"melt","text":"Oils, emollients and emulsifiers are heated together in a separate vessel until they flow. Oil and emollient bases are the oldest kind of foundation, and water emulsions came after World War II.","inputs":["vegetable-oil","silicone"]},{"name":"Emulsify the two phases","process":"mix","text":"The warm oil phase is added to the pigment dispersion with constant stirring. Emulsifiers keep the oil and water from separating, and they were the breakthrough behind modern liquid foundation.","inputs":[]},{"name":"Cool and add fragrance","process":"chill","text":"The mixture is cooled while being stirred, and fragrance goes in once the batch is warm rather than hot. Stirring carries on until it reaches room temperature.","inputs":["perfume"]},{"name":"Match the shade","process":"inspect","text":"The batch color is compared with the target shade, because the amount of pigment decides both color and coverage. Sheer foundation holds 8 to 13 percent pigment and light coverage 13 to 18 percent.","inputs":[]},{"name":"Fill the bottle","process":"fill","text":"The finished foundation is filled into bottles, tubes or compact pans.","inputs":["plastic-bottle"]}],"facts":["The first commercial foundation was Max Factor's Pan-Cake, developed for use in film.","Max Factor created Flexible Greasepaint in 1914, which reflected the lighting on movie sets better than earlier makeup.","Professional stage foundation can hold up to 50 percent pigment."],"where":[],"whereNote":null,"sources":[{"title":"Foundation (cosmetics)","url":"https://en.wikipedia.org/wiki/Foundation_(cosmetics)"},{"title":"US patent 6,692,729: cosmetic resin composition, with foundation examples","url":"https://patents.google.com/patent/US6692729"},{"title":"How makeup is made (Konica Minolta)","url":"https://sensing.konicaminolta.us/us/blog/how-makeup-is-made/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"fountain-pen","name":"Fountain pen","kind":"product","category":"plastics","title":"How fountain pens are made","url":"https://assemblyline.org/make/fountain-pen","stations":6,"upstream":51,"downstream":0,"depth":7,"dek":"A fountain pen writes by capillary action, the same force that pulls water up a paper towel.","answer":"A fountain pen nib is cut from a flat sheet of metal, tipped with a hard alloy ball, and split with a thin saw so the two halves can flex. The barrel is turned or molded, and a plastic feed under the nib meters ink. Pieces are assembled, then every pen is writing-tested.","aka":["ink pen","nib pen"],"inputs":["stainless-steel","gold","plastic","brass"],"uses":[],"grounds":["gold-ore","water","natural-gas","chromite","limestone","air","nickel-ore","zinc-ore","rock-salt","crude-oil","copper-ore","lead-ore","tin-ore","coal","trona","sulfur","bauxite","corn","sugarcane","sugar-beet"],"upstreamSlugs":["stainless-steel","gold","plastic","brass","steel-scrap","chromium","nickel","oxygen","argon","gold-ore","water","lime","zinc","chlorine","naphtha","natural-gas","ethylene","propylene","copper","lead","tin","aluminum","propane","chromite","coke","soda-ash","limestone","air","nickel-ore","sulfuric-acid","zinc-ore","rock-salt","crude-oil","hydrogen","copper-ore","lead-ore","tin-ore","coal","petroleum-coke","alumina","ammonia","carbon-dioxide","trona","sulfur","bauxite","caustic-soda","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Stamp the nib blank","process":"stamp","text":"A flat nib shape is stamped out of a sheet of stainless steel or gold alloy. It is then curved to give the point its spring.","inputs":["stainless-steel","gold"]},{"name":"Weld on the tip","process":"weld","text":"A tiny ball of very hard metal is welded to the point, so the nib survives years of rubbing on paper.","inputs":[]},{"name":"Slit the point","process":"cut","text":"A very thin spinning blade cuts a slit from the tip back to a small breather hole. The slit splits the tip into two tines, and ink flows down it by capillary action.","inputs":[]},{"name":"Grind the tip smooth","process":"grind","text":"The tip is ground and polished, often by hand, until it glides over paper without catching.","inputs":[]},{"name":"Make the barrel","process":"mold","text":"Cheaper barrels are injection-molded from plastic. Premium ones are turned on a lathe from metal or resin.","inputs":["plastic","brass"]},{"name":"Assemble and write-test","process":"assemble","text":"The nib and a plastic feed that regulates ink flow are pushed into the section, joined to the barrel with a filling system, and fitted with cap and clip. Each pen is tested by writing with it.","inputs":[]}],"facts":["Lewis Waterman launched a commercially viable fountain pen in 1884, selling 36 a week from a cigar kiosk in New York at first.","The Parker Pen Company made the first pen without an ink sac in 1932.","Premium nibs are usually 18 to 22 karat gold, while steel took over on cheaper pens as gold prices rose."],"where":[],"whereNote":null,"sources":[{"title":"The Fountain Pen: From Ancient Origins to Modern Mastery","url":"https://www.mfgrobots.com/Article/mfg/mpm/2023.html"},{"title":"Fountain pen","url":"https://en.wikipedia.org/wiki/Fountain_pen"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"french-fries","name":"Frozen french fries","kind":"product","category":"food","title":"How frozen french fries are made","url":"https://assemblyline.org/make/french-fries","stations":7,"upstream":10,"downstream":0,"depth":4,"dek":"Factory fries are fried twice, first in the plant and then in your kitchen, with a deep freeze between.","answer":"Russet potatoes are steam-peeled, cut into strips by water-driven knives, blanched and air-dried. A short fry in oil sets the surface before the strips are frozen. At home or in a restaurant, the second fry finishes the job. Since the 1960s, most American fries have been made from frozen potatoes.","aka":["fries","chips","frozen fries","finger chips"],"inputs":["potatoes","water","vegetable-oil"],"uses":[],"grounds":["potatoes","water","soybeans","rapeseed","clay","crude-oil","natural-gas"],"upstreamSlugs":["potatoes","water","vegetable-oil","soybeans","rapeseed","hexane","clay","crude-oil","hydrogen","natural-gas"],"downstreamSlugs":[],"steps":[{"name":"Steam-peel the potatoes","process":"wash","text":"Potatoes are blasted with steam in a pressure vessel, which loosens the skin so it can be scrubbed off with brushes. Russets are the usual variety for fries.","inputs":["potatoes","water"]},{"name":"Fire them through a knife","process":"cut","text":"Water carries potatoes through a bank of blades at high speed, and they come out as even strips. Cameras then spot and remove strips that have dark defects.","inputs":[]},{"name":"Blanch in hot water","process":"cook","text":"Strips pass through a hot bath that partly cooks them and leaches out sugars. Removing sugar prevents dark, bitter spots when they are fried.","inputs":[]},{"name":"Dry with warm air","process":"dry","text":"Blanched strips travel through a dryer to take surface water away. Drier strips fry crisper and take up less oil.","inputs":[]},{"name":"Par-fry in oil","process":"cook","text":"Strips are fried briefly in vegetable oil. This first fry cooks the starch and sets a thin crust, ready for the second fry. Restaurants do this step at about 160 °C, while the second hot fry at about 190 °C turns the outside golden.","inputs":["vegetable-oil"]},{"name":"Freeze them solid","process":"chill","text":"Strips move through a freezing tunnel. Freezing quickly keeps ice crystals small so the cells do not burst and turn mushy later.","inputs":[]},{"name":"Bag and ship frozen","process":"package","text":"Fries are weighed into bags or cartons and stored at deep-freeze temperature until they are shipped in refrigerated trucks.","inputs":[]}],"facts":["Thomas Jefferson had potatoes served in the French manner at a White House dinner in 1802.","Belgium and France have an ongoing dispute about where fries were invented."],"where":[],"whereNote":null,"sources":[{"title":"French fries","url":"https://en.wikipedia.org/wiki/French_fries"},{"title":"Potato chip","url":"https://en.wikipedia.org/wiki/Potato_chip"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"frozen-peas","name":"Frozen peas","kind":"product","category":"food","title":"How frozen peas are made","url":"https://assemblyline.org/make/frozen-peas","stations":6,"upstream":8,"downstream":0,"depth":5,"dek":"A frozen pea is often frozen within hours of leaving the vine, while a fresh one keeps aging on its way to the store.","answer":"A pea harvester strips the pods from the vines in the field, and the peas are shelled and rushed to the plant. They are chilled and washed, then blanched in hot water for a few minutes to stop the enzymes that spoil them. Cold air then freezes them as loose, individual peas.","aka":["frozen green peas","garden peas"],"inputs":["peas","polyethylene"],"uses":[],"grounds":["peas","natural-gas","water","crude-oil"],"upstreamSlugs":["peas","polyethylene","ethylene","naphtha","natural-gas","water","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Strip the vines","process":"harvest","text":"A pea viner machine strips peas from their vines in the field. Peas must go into the freezing process shortly after picking, or they spoil.","inputs":["peas"]},{"name":"Shell and sort","process":"separate","text":"Peas are shelled and sorted. The more tender the peas, the more likely they are to be kept for the final product.","inputs":[]},{"name":"Chill and rinse","process":"wash","text":"Peas are placed in ice water to cool, then sprayed with water to remove any dirt or dust.","inputs":[]},{"name":"Scald them briefly","process":"cook","text":"The peas are boiled for a few minutes, which deactivates the enzymes that cause browning, off flavors and texture changes in storage. Then they are cooled quickly so the cooking stops.","inputs":[],"spec":"a few minutes in hot water"},{"name":"Freeze each pea alone","process":"chill","text":"Small foods are often frozen in a fluidized bed, where fast cold air from below lifts and tumbles the pieces. Quick freezing makes small ice crystals and keeps the cell structure intact. Other plants use air-blast tunnels.","inputs":[]},{"name":"Bag the peas","process":"package","text":"The free-flowing peas are weighed into bags and kept cold. They freeze as separate pieces, so the bag can be poured by the handful.","inputs":["polyethylene"]}],"facts":["The first pea harvesting machine able to shell peas through impact was invented around 1890 by John Alexander Chisholm.","Freezing slows spoilage because microorganisms do not grow when food is colder than about minus 9.5 °C."],"where":[],"whereNote":null,"sources":[{"title":"Pea","url":"https://en.wikipedia.org/wiki/Pea"},{"title":"Blanching (cooking)","url":"https://en.wikipedia.org/wiki/Blanching_(cooking)"},{"title":"Frozen food","url":"https://en.wikipedia.org/wiki/Frozen_food"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"frozen-pizza","name":"Frozen pizza","kind":"product","category":"food","title":"How frozen pizza is made","url":"https://assemblyline.org/make/frozen-pizza","stations":8,"upstream":40,"downstream":0,"depth":9,"dek":"A frozen pizza crust needs its own waterproofing, or the sauce soaks it into mush.","answer":"A factory mixes and rolls dough into crusts, seals them with a thin coating so sauce cannot soak in, then adds sauce, cheese and toppings. Many lines bake the pizza on a conveyor before freezing it hard, wrapping it and shipping it cold. Self-rising crusts go in unbaked and rise in the buyer's oven.","aka":["pizza from the freezer","frozen pie"],"inputs":["flour","water","yeast","baking-soda","tomatoes","mozzarella","sausage"],"uses":[],"grounds":["water","tomatoes","wheat","trona","limestone","rock-salt","pigs","air","sugarcane","sugar-beet","natural-gas","corn","raw-milk","seawater","cattle-hide","crude-oil"],"upstreamSlugs":["flour","water","yeast","baking-soda","tomatoes","mozzarella","sausage","wheat","vitamin-c","molasses","trona","limestone","ammonia","rock-salt","soda-ash","carbon-dioxide","pasteurized-milk","table-salt","pigs","sausage-casing","corn-starch","hydrogen","air","sugar","plastic-bottle","sugarcane","sugar-beet","natural-gas","lime","corn","raw-milk","seawater","cattle-hide","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Mix the crust dough","process":"mix","text":"Flour, water and salt are combined with yeast or baking soda and a little oil. Self-rising crusts carry leavening agents so they puff up in the buyer's oven the way a pizzeria crust does.","inputs":["flour","water","yeast","baking-soda"]},{"name":"Press it into rounds","process":"roll","text":"The dough is rolled or pressed flat and cut into discs, thick or thin depending on the product.","inputs":[]},{"name":"Seal the crust surface","process":"coat","text":"An edible sealing agent goes on top of the crust. Without it, sauce leaks into the dough while the pizza bakes at home and the crust turns soggy.","inputs":[]},{"name":"Spread sauce and cheese","process":"assemble","text":"A line of machines drops sauce and shredded cheese onto each crust. Cheap pizzas often use a cheese analogue designed to melt well and stay chewy.","inputs":["tomatoes","mozzarella"]},{"name":"Add the toppings","process":"assemble","text":"Meats and vegetables are scattered on top. The most popular varieties carry both, such as pepperoni or sausage with peppers and onions.","inputs":["sausage"]},{"name":"Bake on a conveyor","process":"bake","inputs":[],"spec":"150 to 232 °C","text":"Many lines carry the topped pizzas through a tunnel oven before freezing. Self-rising crusts stay raw at this point and finish in the buyer's oven."},{"name":"Freeze it solid","process":"chill","text":"Pizzas ride through liquid nitrogen or an air-blast freezer. Faster freezing makes smaller ice crystals and keeps the food's texture, and frozen food stops spoiling once it is below about minus 9.5 °C.","inputs":[]},{"name":"Wrap and box","process":"package","text":"Vacuum sealing helps stop moisture from the air from creeping into the crust. The wrapped pizzas are boxed and moved through the cold chain.","inputs":[]}],"facts":["The first recorded patent for frozen pizza was filed in 1950 by Joseph Bucci.","Totino's started mass-manufacturing frozen pizzas in 1962 and sold to Pillsbury in 1975 for US$22,000,000.","In the 1970s competition drove makers to swap real cheese for cheese analogues and to stretch the tomato sauce."],"where":[],"whereNote":null,"sources":[{"title":"Frozen pizza","url":"https://en.wikipedia.org/wiki/Frozen_pizza"},{"title":"Frozen food","url":"https://en.wikipedia.org/wiki/Frozen_food"},{"title":"Pizza","url":"https://bakerpedia.com/processes/pizza/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gallium","name":"Gallium","kind":"material","category":"electronics","title":"How gallium is recovered","url":"https://assemblyline.org/make/gallium","stations":5,"upstream":5,"downstream":11,"depth":2,"dek":"Gallium melts in your hand, and none of it is mined on purpose. It is a by-product of making aluminum.","answer":"Gallium has no ore of its own. It collects as a trace in the sodium hydroxide liquor used to turn bauxite into alumina, and is pulled out with ion-exchange resin. At a typical 50 ppm in the bauxite, about 15 percent of the gallium can be recovered. Smaller amounts come out of zinc ores.","aka":["Ga","gallium metal"],"inputs":["bauxite","caustic-soda","zinc-ore"],"uses":["led"],"grounds":["bauxite","zinc-ore","rock-salt","water"],"upstreamSlugs":["bauxite","caustic-soda","zinc-ore","rock-salt","water"],"downstreamSlugs":["led","led-bulb","lcd-screen","television","computer-mouse","pinball-machine","e-reader","remote-control","laptop","smartwatch","digital-camera"],"steps":[{"name":"Dissolve bauxite in lye","process":"react","text":"In the Bayer process, bauxite is digested in sodium hydroxide to make alumina. Gallium in the ore dissolves and builds up in the circulating liquor.","inputs":["bauxite","caustic-soda"]},{"name":"Capture it on resin","process":"separate","text":"Ion-exchange resin pulls gallium out of the liquor. The remainder ends up in red mud and aluminum hydroxide.","inputs":[],"spec":"about 15% recovered at 50 ppm"},{"name":"Tap the zinc side stream","process":"separate","text":"A smaller supply comes from sulfidic zinc ores, where sphalerite hosts the gallium. Smelters recover it from process residues.","inputs":["zinc-ore"]},{"name":"Refine to high purity","process":"refine","text":"Crude gallium is purified until it is a very pure silvery blue metal. Electronics need that purity for gallium arsenide and gallium nitride.","inputs":[]},{"name":"Pour into ingots","process":"cast","text":"The metal melts just above room temperature, so it is poured and shipped in small containers. A handful will melt at body temperature.","inputs":[]}],"facts":["Gallium melts at 29.7646 °C, just above room temperature, and is a formal temperature reference point.","Only four non-radioactive metals are liquid at or near room temperature, and gallium is one of them.","Gallium nitride makes the blue and violet LEDs in modern lighting."],"where":[],"whereNote":null,"sources":[{"title":"Gallium","url":"https://en.wikipedia.org/wiki/Gallium"},{"title":"Indium","url":"https://en.wikipedia.org/wiki/Indium"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"garden-hose","name":"Garden hose","kind":"product","category":"plastics","title":"How garden hoses are made","url":"https://assemblyline.org/make/garden-hose","stations":6,"upstream":48,"downstream":0,"depth":7,"dek":"A garden hose is a plastic tube wrapped in woven thread and then covered in a second layer of plastic.","answer":"PVC granules are melted in an extruder and pushed through a die that shapes the inner tube. As the tube leaves the die, a braiding machine weaves polyester or nylon yarn over it, and a second extruder coats the braid with an outer layer. The hose is cooled and sized, printed and coiled, and brass or plastic couplings are fitted.","aka":["garden hosepipe","water hose","hosepipe"],"inputs":["pvc","polyester","brass"],"uses":[],"grounds":["water","natural-gas","rock-salt","iron-ore","sulfur","air","copper-ore","zinc-ore","lead-ore","tin-ore","crude-oil","coal","titanium-ore","bauxite","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["pvc","polyester","brass","ethylene","chlorine","water","pigment","plasticizer","pet-plastic","copper","zinc","lead","tin","aluminum","naphtha","natural-gas","rock-salt","sulfuric-acid","iron-ore","titanium-dioxide","carbon-black","sulfur","air","propylene","p-xylene","ethylene-glycol","copper-ore","oxygen","zinc-ore","lead-ore","coke","tin-ore","crude-oil","coal","petroleum-coke","alumina","hydrogen","titanium-ore","carbon-dioxide","bauxite","caustic-soda","lime","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Dry the PVC granules","process":"dry","text":"Granules of PVC compound are fed from silos. They must be dry, so they are sometimes pre-dried for an hour or two.","inputs":["pvc"]},{"name":"Melt and extrude the tube","process":"extrude","text":"Twin screws push the granules through heated zones until they melt into a thick, even liquid. A die shapes it into the hollow inner tube, which sets the bore of the hose.","inputs":[]},{"name":"Braid yarn over the tube","process":"weave","text":"Right after the die, a braider weaves yarn in crossing spirals around the tube. The reinforcement is polyester or nylon thread, and it lets the hose take pressure without ballooning.","inputs":["polyester"]},{"name":"Extrude the outer cover","process":"coat","text":"A second extruder wraps a layer of plastic over the braid. The cover has to bond with the tube through the gaps in the thread.","inputs":["pvc"]},{"name":"Cool and size","process":"chill","text":"The hose is drawn through a vacuum sizing tank or water bath that hardens it and holds its outside diameter constant. Gradual cooling prevents stress and distortion.","inputs":[]},{"name":"Print, cut and fit couplings","process":"assemble","text":"The hose is marked with its brand, cut or coiled, and a male and female coupling are fitted to the ends. Better hoses have couplings machined from brass.","inputs":["brass"]}],"facts":["Soaker hoses leak all along their length, either through many small holes or through a porous material such as sintered rubber particles.","The threads on a hose end are not tapered, so a small rubber washer in the female end, not the threads, makes the seal.","Hoses for drinking water use polymers tested not to leach plasticizers called phthalates into the water."],"where":[],"whereNote":null,"sources":[{"title":"How to produce PVC flexible hose tube by using PVC granules?","url":"https://www.inpvc.com/news/how-to-produce-pvc-flexible-hose-tube-by-using-pvc-granules-2"},{"title":"Garden hose","url":"https://en.wikipedia.org/wiki/Garden_hose"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gas-cylinder","name":"Gas cylinder","kind":"product","category":"hardware","title":"How gas cylinders are made","url":"https://assemblyline.org/make/gas-cylinder","stations":10,"upstream":73,"downstream":0,"depth":10,"dek":"A steel gas cylinder can begin as a flat disc, drawn two or three more times until it is a tall weld-free tube.","answer":"Many weld-free steel cylinders start as a flat disc stamped from annealed plate. A hydraulic press cold-draws it into a cup, which is annealed and drawn again until the wall is thin enough. The top is heated and hot spun shut into a shoulder and neck. Quenching, tempering, threading and a water pressure test follow, then stamping, a valve and paint.","aka":["gas bottle","compressed gas cylinder","tank"],"inputs":["steel","brass","paint"],"uses":[],"grounds":["water","iron-ore","limestone","air","dolomite","manganese-ore","natural-gas","copper-ore","zinc-ore","lead-ore","tin-ore","crude-oil","coal","titanium-ore","sulfur","quartz","timber","bauxite","rock-salt","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["steel","brass","paint","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","copper","zinc","lead","tin","aluminum","water","titanium-dioxide","pigment","acrylic","tin-can","iron-ore","coke","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","copper-ore","zinc-ore","lead-ore","tin-ore","crude-oil","coal","petroleum-coke","alumina","titanium-ore","chlorine","carbon-black","sulfur","propylene","ammonia","methanol","tinplate","lacquer","ink","quartz","charcoal","timber","bauxite","caustic-soda","rock-salt","naphtha","ethanol","vegetable-oil","phenolic-resin","hydrogen","corn","sugarcane","yeast","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","molasses","benzene","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Stamp the discs","process":"stamp","text":"Discs are stamped from annealed plate or coil, with chromium-molybdenum grades such as 4130 a common choice. Each size needs its own blank.","inputs":["steel"]},{"name":"Draw into a cup","process":"draw","text":"The lubricated disc is pushed cold through dies by a hydraulic press to form a cup. A rival route skips this, backward-extruding a heated billet and then hot drawing it.","inputs":[]},{"name":"Anneal and redraw","process":"draw","text":"Work hardening is relieved in a furnace, scale is blasted off, and the cup goes through another die. It repeats for two or three more stages, with the cup getting narrower and longer each time.","inputs":[]},{"name":"Spin the shoulder","process":"forge","text":"The base is formed and the top trimmed to length. The top is heated to bright red and spun while a hardened block folds the metal inward, like a potter closing a vase. This thickens the shoulder and closes the neck.","inputs":[]},{"name":"Quench and temper","process":"heat-treat","text":"The formed shell is quenched and then tempered to give the best mix of strength and toughness. A study of 34CrMo4 steel cylinders used 870 °C and 620 °C.","inputs":[]},{"name":"Clean and thread","process":"machine","text":"Shot blasting or chemical cleaning removes the scale, inside and out. The neck is machined with its thread and any o-ring seat.","inputs":[]},{"name":"Test with water","process":"inspect","text":"After inspection each shell is filled with water for a hydrostatic test. For weld-free high-pressure types the test pressure is usually 1.5 times working pressure, or 1.67 times in the United States.","inputs":[],"spec":"1.5 to 1.67 times working pressure"},{"name":"Stamp the markings","process":"stamp","text":"Cylinders that pass get a serial number and other permanent markings stamped on, along with a neck ring in one plant's sequence.","inputs":[]},{"name":"Fit the valve","process":"assemble","text":"Into the threaded neck goes a valve, then a cap.","inputs":["brass"]},{"name":"Paint the outside","process":"coat","text":"A corrosion barrier paint covers the outside, or the shell is hot dip galvanized instead.","inputs":["paint"]}],"facts":["A Type 1 cylinder is all metal and mostly forged weld-free steel or aluminum.","Steel cylinders are the most resistant to rough handling and the most economical.","Type 4 cylinders have a plastic liner fully wrapped in fiber composite, with only the neck made of metal."],"where":[],"whereNote":null,"sources":[{"title":"Gas cylinder","url":"https://en.wikipedia.org/wiki/Gas_cylinder"},{"title":"Microstructure and Mechanical Properties of 34CrMo4 Steel for Gas Cylinders","url":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6515862/"},{"title":"Cylinder manufacturing, Weld Talk (posts by a former plant foreman)","url":"https://weldtalk.hobartwelders.com/forum/equipment-talk/shielding-gases/33391-cylinder-manufacturing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gasoline","name":"Gasoline","kind":"product","category":"chemicals","title":"How gasoline is made","url":"https://assemblyline.org/make/gasoline","stations":6,"upstream":12,"downstream":4,"depth":5,"dek":"Gasoline is a blend of several refinery streams, and the raw distilled part is not good enough for a modern engine.","answer":"Gasoline is blended from several refinery streams. Crude oil is distilled, heavy fractions are broken down in a catalytic cracker, and naphtha is reformed to raise its octane rating. These components, plus ethanol and additives, are mixed to the seasonal specification. Straight distilled gasoline alone would knock too much in modern engines.","aka":["petrol","motor spirit","gas"],"inputs":["crude-oil","naphtha","hydrogen","ethanol"],"uses":["car","car-engine","motorcycle"],"grounds":["crude-oil","water","natural-gas","corn","sugarcane","sugar-beet"],"upstreamSlugs":["crude-oil","naphtha","hydrogen","ethanol","water","natural-gas","corn","sugarcane","yeast","ethylene","molasses","sugar-beet"],"downstreamSlugs":["car","car-engine","motorcycle","locomotive"],"steps":[{"name":"Wash and distill the crude","process":"refine","text":"Desalted crude oil is heated and fed into a tall tower where it separates into fractions. The light fraction that comes off the top is straight-run gasoline and naphtha.","inputs":["crude-oil"]},{"name":"Crack the heavy oil","process":"react","text":"Heavy gas oil from the bottom of the tower meets a hot powdered catalyst that breaks its long molecules into short ones. This corrects the imbalance between what a barrel of crude yields and how much gasoline drivers want.","inputs":[]},{"name":"Reform the naphtha","process":"react","text":"Naphtha is heated with a catalyst, which rearranges its molecules into compounds that resist knocking. The process also gives off hydrogen that the refinery uses elsewhere.","inputs":["naphtha"]},{"name":"Remove the sulfur","process":"react","text":"Each stream is treated with hydrogen to remove sulfur, which would poison emission-control catalysts in cars. The hydrogen sulfide is captured and turned into sulfur.","inputs":["hydrogen"]},{"name":"Blend to specification","process":"mix","text":"Computer-controlled blenders combine the streams and ethanol to meet an octane rating and a seasonal vapor pressure. Summer blends are less volatile, to limit evaporation.","inputs":["ethanol"]},{"name":"Test and dispatch","process":"inspect","text":"Samples are tested before the batch leaves the tank. Pipelines, trains and tank trucks carry it to terminals.","inputs":[]}],"facts":["Tetraethyl lead was once widely added to raise octane, but American gasoline phased it out starting in 1975 because of the health hazard.","The Shukhov cracking process of 1891 was the world's first commercial way to break heavier crude oil components into lighter ones.","About one-third of the crude oil refined at refineries with a fluid catalytic cracker runs through that cracker to make high-octane gasoline and fuel oils."],"where":[],"whereNote":null,"sources":[{"title":"Gasoline","url":"https://en.wikipedia.org/wiki/Gasoline"},{"title":"Fluid catalytic cracking","url":"https://en.wikipedia.org/wiki/Fluid_catalytic_cracking"},{"title":"Catalytic reforming","url":"https://en.wikipedia.org/wiki/Catalytic_reforming"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gelatin","name":"Gelatin","kind":"material","category":"food","title":"How gelatin is made","url":"https://assemblyline.org/make/gelatin","stations":7,"upstream":5,"downstream":8,"depth":2,"dek":"Gelatin is boiled-down collagen from pig skins and cattle bones, and the cure alone can take weeks.","answer":"Gelatin factories take pork skins, cattle bones and split hides, which are by-products of the meat and leather trades. They clean and cure the raw material in acid or alkali for days to weeks, then extract the loosened collagen with hot water in several rounds. The thin broth is filtered, evaporated, sterilized, dried and ground.","aka":["gelatine","gelatin powder","hydrolyzed collagen"],"inputs":["pigs","cattle-hide","water","lime"],"uses":["yogurt","gummy-bears","marshmallow","wine","gelatin-dessert","gelatin-capsule","banknote"],"grounds":["pigs","cattle-hide","water","limestone"],"upstreamSlugs":["pigs","cattle-hide","water","lime","limestone"],"downstreamSlugs":["yogurt","gummy-bears","marshmallow","wine","gelatin-dessert","gelatin-capsule","banknote","champagne"],"steps":[{"name":"Collect meat-trade leftovers","process":"harvest","text":"Most gelatin starts as pork skins, pork and cattle bones, or split cattle hides. These are by-products of the meat and leather industries, and fish skins can be used for gelatin that avoids some religious objections.","inputs":["pigs","cattle-hide"]},{"name":"Strip fat and minerals","process":"wash","text":"Bones are soaked in dilute acid to dissolve calcium and other salts, and hot water or solvents pull the fat down to under 1 percent. Hides and skins are cut small, washed, de-haired and degreased.","inputs":["water"]},{"name":"Cure in acid or lime","process":"react","text":"The cleaned material soaks in an acid bath or a lime bath so the tight collagen bonds loosen. Acid suits delicate pig skin and normally takes 10 to 48 hours. Alkali cures last far longer, and the whole curing stage may take several weeks.","inputs":["lime"]},{"name":"Extract in hot water","process":"cook","text":"Hot water or dilute acid washes the loosened collagen in several rounds. Early rounds give the strongest gelatin, and later, hotter rounds give weaker gelatin.","inputs":["water"]},{"name":"Filter and clarify","process":"refine","text":"The thin brown broth is filtered through earth and cloth to take out fat, fiber and haze, then deionized to remove salts.","inputs":[]},{"name":"Evaporate and sterilize","process":"pasteurize","text":"The clear solution is thickened in vacuum evaporators and briefly heated at high temperature to sterilize it. Heat, alkaline treatment and filtration are the steps regulators credit with lowering any infectious risk from bovine raw material.","inputs":[]},{"name":"Chill, dry and grind","process":"dry","text":"The concentrate sets to a gel, is chopped into noodles, and is dried on a belt in warm air. The brittle gelatin is then ground and sifted, and batches are blended to a target gel strength.","inputs":[]}],"facts":["Dry gelatin is 98 to 99% protein, yet it lacks the amino acid tryptophan.","Gelatin soaks up 5 to 10 times its own weight in water to form a gel."],"where":[],"whereNote":null,"sources":[{"title":"Gelatin","url":"https://en.wikipedia.org/wiki/Gelatin"},{"title":"Hydrogenation","url":"https://en.wikipedia.org/wiki/Hydrogenation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gelatin-capsule","name":"Gelatin capsule","kind":"product","category":"body-health","title":"How gelatin capsules are made","url":"https://assemblyline.org/make/gelatin-capsule","stations":5,"upstream":20,"downstream":0,"depth":5,"dek":"Hard capsules are made by dipping metal pins into warm gelatin, like candle-making in miniature.","answer":"Gelatin capsules are made from gelatin dissolved in water, with glycerin or sorbitol added to soften them. Hard capsules come from dipping metal pins in the gelatin solution, rotating them, drying, stripping, trimming and joining two halves. Softgels are formed and filled in one step on a rotary die.","aka":["gel cap","softgel","capsule","pill capsule"],"inputs":["gelatin","glycerin","water"],"uses":[],"grounds":["water","pigs","cattle-hide","limestone","oil-palm-fruit","soybeans","rapeseed","clay","rock-salt","natural-gas","crude-oil"],"upstreamSlugs":["gelatin","glycerin","water","pigs","cattle-hide","lime","palm-oil","vegetable-oil","caustic-soda","methanol","limestone","oil-palm-fruit","soybeans","rapeseed","hexane","clay","rock-salt","natural-gas","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Dissolve the gelatin","process":"mix","text":"Gelatin, made from the collagen of animal skin or bone, is dissolved in water. Plasticizers such as glycerin or sorbitol, colorings and preservatives may be added.","inputs":["gelatin","glycerin","water"]},{"name":"Dip the pins","process":"coat","text":"For hard capsules, metal pins are dipped into the gelatin solution. The pins are rotated as the gelatin sets on them in a thin film.","inputs":[]},{"name":"Dry and strip","process":"dry","text":"The coated pins pass through drying, then the dried shells are stripped off and trimmed to length. The two parts are a smaller body and a larger cap.","inputs":[]},{"name":"Fill the body","process":"fill","text":"The body is filled with dry powder or small pellets by a capsule filling machine. Fill weight is checked in real time.","inputs":[]},{"name":"Join the halves","process":"assemble","text":"The cap is pressed on over the filled body to close the capsule. Softgels skip the pins, because a rotary die forms, fills and seals them in one step.","inputs":[]}],"facts":["The two-piece telescoping gelatin capsule was patented by James Murdoch of London in 1847.","Mothes and Dublanc patented a single-piece sealed gelatin capsule in 1833, filling each one by medicine dropper.","Vegetable capsules made from cellulose were introduced in 1989, though gelatin is still cheaper."],"where":[],"whereNote":null,"sources":[{"title":"Capsule (pharmacy)","url":"https://en.wikipedia.org/wiki/Capsule_(pharmacy)"},{"title":"Gelatin","url":"https://en.wikipedia.org/wiki/Gelatin"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gelatin-dessert","name":"Gelatin dessert","kind":"product","category":"food","title":"How gelatin dessert is made","url":"https://assemblyline.org/make/gelatin-dessert","stations":5,"upstream":9,"downstream":0,"depth":3,"dek":"Jelly was once a status symbol, because getting gelatin out of calves' feet took a large kitchen staff.","answer":"Gelatin dessert is made by dissolving gelatin in hot water with sugar, flavoring and acids, then chilling the liquid until it sets into a soft elastic gel. Factories sell it as a premixed dry powder or block. The gelatin itself is processed collagen from animal skin and bones.","aka":["jelly","jello","gelatine dessert"],"inputs":["gelatin","sugar","water"],"uses":[],"grounds":["water","pigs","cattle-hide","sugarcane","sugar-beet","limestone"],"upstreamSlugs":["gelatin","sugar","water","pigs","cattle-hide","lime","sugarcane","sugar-beet","limestone"],"downstreamSlugs":[],"steps":[{"name":"Blend the dry mix","process":"mix","text":"Gelatin is combined with sweetener, flavoring and food coloring. Acids and salts such as adipic acid, fumaric acid and sodium citrate are included in commercial blends to adjust tartness.","inputs":["gelatin","sugar"]},{"name":"Pack powder or blocks","process":"package","text":"The blend is sold as a loose powder or as a block divided into small squares. Both are meant to dissolve fully in hot water.","inputs":[]},{"name":"Dissolve in hot water","process":"cook","text":"The mix is stirred into hot water until every granule is dissolved. Sprinkling the powder into liquid several minutes before heating, called blooming, helps it dissolve.","inputs":["water"]},{"name":"Pour into molds","process":"mold","text":"The warm liquid is poured into decorative molds. Layers of different colors can be built up one on another, each set before the next goes in.","inputs":[]},{"name":"Chill until it sets","process":"chill","text":"The molds go into the refrigerator. As the liquid cools the dissolved protein strands tangle into a network that holds the water in place, and the gel melts back to a thick liquid if it warms up.","inputs":[]}],"facts":["Before gelatin was sold ready-made, jelly meant calf's foot jelly, and having it showed that a household had a big kitchen staff.","The United States federal government does not classify gelatin dessert as a meat product, because the collagen is processed so extensively.","Hannah Glasse was the first to record jelly in trifle, in her 1747 book The Art of Cookery."],"where":[],"whereNote":null,"sources":[{"title":"Gelatin dessert","url":"https://en.wikipedia.org/wiki/Gelatin_dessert"},{"title":"Gelatin","url":"https://en.wikipedia.org/wiki/Gelatin"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"germanium","name":"Germanium","kind":"material","category":"electronics","title":"How germanium is recovered","url":"https://assemblyline.org/make/germanium","stations":5,"upstream":10,"downstream":1,"depth":4,"dek":"Zone refining can purify germanium to one impurity atom in ten billion.","answer":"Germanium is a by-product of zinc smelting, recovered from sphalerite where it concentrates at up to 0.3 percent, and from coal fly ash in some countries. Zinc concentrate is roasted and leached with acid, germanium precipitates out, and it is converted to a volatile chloride for purification. Zone refining then gives semiconductor grade.","aka":["Ge","germanium metal"],"inputs":["zinc-ore","sulfuric-acid","hydrochloric-acid","hydrogen"],"uses":["optical-fiber"],"grounds":["zinc-ore","sulfur","air","water","natural-gas","rock-salt"],"upstreamSlugs":["zinc-ore","sulfuric-acid","hydrochloric-acid","hydrogen","sulfur","air","water","chlorine","natural-gas","rock-salt"],"downstreamSlugs":["optical-fiber"],"steps":[{"name":"Roast the ore concentrate","process":"fire","text":"Sulfide concentrates are heated in air to turn them into oxides. Some germanium stays in the dust and some becomes germanates.","inputs":["zinc-ore"]},{"name":"Leach with sulfuric acid","process":"react","text":"Acid dissolves zinc and germanates from the cinder. After neutralization the zinc stays dissolved while germanium and other metals drop out.","inputs":["sulfuric-acid"]},{"name":"Concentrate the oxide","process":"separate","text":"The precipitate goes through the Waelz process to remove part of the zinc, and a second leach brings out germanium dioxide.","inputs":[]},{"name":"Convert to a liquid chloride","process":"react","text":"The dioxide reacts with hydrochloric acid or chlorine to make germanium tetrachloride, a fuming liquid that boils at 83.1 °C and can be distilled clean.","inputs":["hydrochloric-acid"]},{"name":"Zone refine the metal","process":"refine","text":"The purified chloride is turned back into oxide and reduced to metal with hydrogen. Zone refining then sweeps a narrow molten band along a bar, and impurities end up at one end.","inputs":["hydrogen"]}],"facts":["Clemens Winkler found germanium in a silver mineral in 1886, filling a gap Mendeleev had predicted.","The first decade of semiconductor electronics was based entirely on germanium."],"where":[{"place":"China","share":"80 tonnes"},{"place":"Russia","share":"5 tonnes"},{"place":"United States","share":"3 tonnes"}],"whereNote":"2011 world output of about 118 tonnes (Wikipedia).","sources":[{"title":"Germanium","url":"https://en.wikipedia.org/wiki/Germanium"},{"title":"Indium","url":"https://en.wikipedia.org/wiki/Indium"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gin","name":"Gin","kind":"product","category":"drink","title":"How gin is made","url":"https://assemblyline.org/make/gin","stations":7,"upstream":25,"downstream":0,"depth":6,"dek":"Gin is vodka that has been given a second life: redistilled with juniper and other plants.","answer":"Gin is neutral alcohol flavored with juniper berries and other plant botanicals. In the best-known method, nearly pure spirit is redistilled with the botanicals so their aroma oils ride the vapor over into the finished gin. Water brings the strength down, and the gin is bottled clear.","aka":["london dry gin","genever","distilled gin"],"inputs":["wheat","yeast","juniper-berries","ethanol","water","glass-bottle"],"uses":[],"grounds":["wheat","juniper-berries","water","corn","sugarcane","silica-sand","limestone","sugar-beet","natural-gas","rock-salt","trona","crude-oil","air"],"upstreamSlugs":["wheat","yeast","juniper-berries","ethanol","water","glass-bottle","molasses","corn","sugarcane","ethylene","silica-sand","soda-ash","limestone","polyethylene","sugar-beet","naphtha","natural-gas","rock-salt","ammonia","carbon-dioxide","lime","trona","crude-oil","hydrogen","air"],"downstreamSlugs":[],"steps":[{"name":"Ferment a grain mash","process":"ferment","text":"Gin starts as ordinary ethanol, often made from cereal grain or molasses. Grain is mashed and fermented with yeast into a weak alcoholic liquid.","inputs":["wheat","yeast"]},{"name":"Distill to neutral spirit","process":"refine","text":"Column stills strip the liquid down to nearly pure ethanol. The column still, developed in 1826 and 1831, made it practical to produce neutral spirits for London dry gin.","inputs":[]},{"name":"Load the botanicals","process":"mix","text":"Juniper berries are the defining flavor. Coriander is the usual runner-up, and distillers add citrus peel, spices and roots. The neutral spirit and botanicals go into the still together.","inputs":["juniper-berries","ethanol"]},{"name":"Redistill with plants","process":"refine","text":"The still heats gently. Aromatic oils from the plants evaporate along with the alcohol and are carried over as vapor. For London gin, the flavor can only come from this distillation.","inputs":[]},{"name":"Collect the heart","process":"separate","text":"The distiller keeps the clean middle of the run and discards the harsh start and end. Distilled gin comes off the still at a high proof.","inputs":[],"spec":"at least 70% ABV for London gin"},{"name":"Dilute to strength","process":"mix","text":"Water reduces the spirit to the bottling strength. Rules for gin vary: the EU minimum is 37.5% for compound gin, and the US minimum is 40%.","inputs":["water"]},{"name":"Bottle it clear","process":"fill","text":"Most gin is bottled without any aging, so it stays clear. London gin may not have more than 0.1 g of sugars added per litre.","inputs":["glass-bottle"]}],"facts":["The word gin is short for genever, an old Dutch name that comes from the Latin for juniper.","London had an estimated 1,500 residential stills in 1726.","Tonic water was created in tropical colonies to mask the bitter taste of quinine, giving us the gin and tonic.","London gin is not a geographical designation, so it can be made anywhere."],"where":[],"whereNote":null,"sources":[{"title":"Gin","url":"https://en.wikipedia.org/wiki/Gin"},{"title":"Distilled beverage","url":"https://en.wikipedia.org/wiki/Distilled_beverage"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"glass","name":"Glass","kind":"material","category":"minerals","title":"How glass is made","url":"https://assemblyline.org/make/glass","stations":5,"upstream":16,"downstream":35,"depth":5,"dek":"About 90% of the glass made today is one recipe, and it is mostly melted sand.","answer":"Glass is sand melted with soda ash and limestone in a gas-fired furnace, then cooled fast enough that its atoms never line up into crystals. The usual soda-lime recipe is around 70% silica. Furnaces run up to 1,575 °C. The syrupy melt is shaped, then slowly cooled in an oven so internal stress does not crack it.","aka":["soda-lime glass","silicate glass"],"inputs":["silica-sand","soda-ash","limestone"],"uses":["thermometer","lcd-screen","oled-screen","hard-drive","camera-sensor","solar-panel","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","floor-tile","neon-sign","smartwatch","e-reader"],"grounds":["silica-sand","limestone","rock-salt","water","trona","natural-gas","air","corn","sugarcane","sugar-beet"],"upstreamSlugs":["silica-sand","soda-ash","limestone","rock-salt","water","ammonia","carbon-dioxide","lime","trona","natural-gas","air","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["thermometer","lcd-screen","oled-screen","hard-drive","camera-sensor","solar-panel","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","floor-tile","neon-sign","smartwatch","e-reader","laptop","television","digital-camera","smartphone","drone","satellite","eyeglass-frame","mustard","salsa","pickles","sauerkraut","jam","hazelnut-spread","mayonnaise"],"steps":[{"name":"Weigh out the batch","process":"mix","text":"Silos hold 1–5 days of sand, soda ash and limestone. Scales, chutes and conveyors measure the recipe and blend it. Crushed scrap glass goes in too, because it melts sooner than raw sand does.","inputs":["silica-sand","soda-ash","limestone"],"spec":"1–5 days of material in the silos"},{"name":"Melt it in the furnace","process":"melt","text":"The batch slides into a furnace fired by natural gas or fuel oil at a slow, steady rate. The hottest furnaces reach 1,575 °C, and the limit is set by how well the furnace roof and walls survive.","inputs":[],"spec":"up to 1,575 °C"},{"name":"Tune the color","process":"mix","text":"Ordinary soda-lime glass looks clear in a thin pane, but iron oxide impurities tint thick pieces green. Glassmakers can add a little manganese dioxide to cancel the green, or add other metal oxides to color the glass on purpose.","inputs":[]},{"name":"Shape it while syrupy","process":"mold","text":"Flat glass is floated out as a ribbon. Bottles start as a gob of glass sheared off a stream and blown in a mold. Either way the glass is shaped while it is still thick enough to hold a form and soft enough to move.","inputs":[]},{"name":"Cool it in a lehr","process":"heat-treat","text":"Glass shrinks as it cools. If the surface sets first and the middle contracts later, the middle ends up pulling against the skin and the piece can fracture. An annealing oven warms the glass to about 580 °C and then lowers the temperature gradually.","inputs":[],"spec":"20–60 minutes of gradual cooling"}],"facts":["Soda-lime glass makes up around 90% of modern manufactured glass.","Glassmaking dates back to at least 3600 BC, long before anyone smelted iron.","Fused quartz glass can survive being plunged into water while red hot."],"where":[],"whereNote":null,"sources":[{"title":"Glass","url":"https://en.wikipedia.org/wiki/Glass"},{"title":"Glass production","url":"https://en.wikipedia.org/wiki/Glass_production"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"glass-bottle","name":"Glass bottle","kind":"product","category":"minerals","title":"How glass bottles are made","url":"https://assemblyline.org/make/glass-bottle","stations":8,"upstream":21,"downstream":37,"depth":5,"dek":"Every bottle starts as a glowing glass sausage sheared off a falling stream, then gets blown twice.","answer":"A glass bottle begins as a measured blob of molten glass, called a gob, sheared from a stream at about 1,050 to 1,200 °C. Compressed air blows the gob into a small rough shape, then into the full bottle in a second mold. An annealing oven relieves stress, and a coating protects the surface.","aka":["glass jar","glass container","beer bottle","wine bottle"],"inputs":["silica-sand","soda-ash","limestone","polyethylene"],"uses":["nail-polish","perfume","penicillin","insulin","vaccine","ketchup","cola","sparkling-water","beer","wine","champagne","whiskey","vodka","gin","rum","tequila","sake","hard-cider","hot-sauce","soda","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","port-wine","prosecco","non-alcoholic-beer"],"grounds":["silica-sand","limestone","rock-salt","water","trona","natural-gas","air","corn","crude-oil","sugarcane","sugar-beet"],"upstreamSlugs":["silica-sand","soda-ash","limestone","polyethylene","rock-salt","water","ammonia","carbon-dioxide","lime","trona","ethylene","natural-gas","air","corn","yeast","naphtha","molasses","crude-oil","hydrogen","sugarcane","sugar-beet"],"downstreamSlugs":["nail-polish","perfume","penicillin","insulin","vaccine","ketchup","cola","sparkling-water","beer","wine","champagne","whiskey","vodka","gin","rum","tequila","sake","hard-cider","hot-sauce","soda","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","port-wine","prosecco","non-alcoholic-beer","shampoo","deodorant","air-freshener","dish-soap","hairspray","foundation-makeup"],"steps":[{"name":"Weigh the batch","process":"mix","text":"A batch house measures sand, soda ash and limestone, mixes them with crushed scrap glass and feeds the blend into the furnace. The recipe changes with the color and purity the bottle needs.","inputs":["silica-sand","soda-ash","limestone"]},{"name":"Melt it in the furnace","process":"melt","text":"Furnaces for container glass are fired by natural gas or fuel oil and can reach 1,575 °C. They are rated by how many metric tons of glass they deliver per day.","inputs":[],"spec":"up to 1,575 °C"},{"name":"Shear off a gob","process":"cut","text":"A blade cuts the stream at its plastic temperature into a cylinder of glass of exactly the weight one bottle needs. The gob falls by gravity through troughs and chutes into the first mold.","inputs":[],"spec":"1,050–1,200 °C"},{"name":"Blow the rough shape","process":"blow","text":"In the blank mold, compressed air or a metal plunger forms the opening of the bottle, called the finish, and a small hollow body called the parison. The \"blow and blow\" method is used for narrow necks, and \"press and blow\" is used for jars.","inputs":[]},{"name":"Flip and blow to size","process":"blow","text":"An arm swings the parison upside down into the final mold. A last blast of air blows the glass out against the mold walls. One machine has 5–20 identical sections, and each section can make one, two, three or four bottles at once.","inputs":[],"spec":"5–20 sections per machine"},{"name":"Treat the inside","process":"react","text":"Bottles for spirits often get a puff of sulfur- or fluorine-bearing gas while hot. It makes the inner surface more resistant to alkali leaching, which can raise the pH of what is in the bottle.","inputs":[]},{"name":"Anneal in the lehr","process":"heat-treat","text":"An annealing oven heats the bottles to about 580 °C and then cools them slowly, so uneven shrinking does not leave them brittle.","inputs":[],"spec":"20–60 minutes"},{"name":"Spray, inspect and pack","process":"coat","text":"A polyethylene coating goes on after annealing for scratch resistance and slipperiness. Machines then check each bottle for defects before it is packed.","inputs":["polyethylene"]}],"facts":["The first glass bottles were made in Mesopotamia around 1500 B.C.","Michael Owens built the first automatic bottle machine in 1904 after working on lightbulb production for Edison.","In the Nordic countries, bottle return rates of 95% are not uncommon."],"where":[],"whereNote":null,"sources":[{"title":"Glass production","url":"https://en.wikipedia.org/wiki/Glass_production"},{"title":"Glass bottle","url":"https://en.wikipedia.org/wiki/Glass_bottle"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"glass-jar","name":"Glass jar","kind":"product","category":"minerals","title":"How glass jars are made","url":"https://assemblyline.org/make/glass-jar","stations":5,"upstream":17,"downstream":7,"depth":6,"dek":"A glass jar is pressed into a rough shape by a plunger and then blown to its final form in a second mold.","answer":"A blob of molten glass, called a gob, drops into a blank mold, where a metal plunger presses it into a thick preform called a parison. The parison flips into a second mold and compressed air blows it out to the jar's final shape. The jar then goes through an annealing oven, called a lehr, which relieves stress.","aka":["mason jar","canning jar","glass container"],"inputs":["glass"],"uses":["mustard","salsa","pickles","sauerkraut","jam","hazelnut-spread"],"grounds":["silica-sand","limestone","rock-salt","water","trona","natural-gas","air","corn","sugarcane","sugar-beet"],"upstreamSlugs":["glass","silica-sand","soda-ash","limestone","rock-salt","water","ammonia","carbon-dioxide","lime","trona","natural-gas","air","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["mustard","salsa","pickles","sauerkraut","jam","hazelnut-spread","mayonnaise"],"steps":[{"name":"Shear off a gob","process":"cut","text":"Molten glass runs from the furnace in a stream. Shears snip it into glowing lumps called gobs, each carrying the weight of one jar.","inputs":["glass"]},{"name":"Press the preform","process":"mold","text":"A gob drops into a blank mold, and a metal plunger presses it out to fill the cavity. This forms the neck and a thick-walled blob called the parison.","inputs":[]},{"name":"Flip and blow it out","process":"blow","text":"The parison swings upside down into the final mold. Compressed air or vacuum pushes the glass out against the walls until it takes the shape of the jar.","inputs":[]},{"name":"Anneal in the lehr","process":"heat-treat","text":"Forming leaves stress in the glass. The jar passes through a long oven that reheats it to relieve the stress and then cools it slowly under control.","inputs":[],"spec":"reheated, then cooled slowly"},{"name":"Inspect every jar","process":"inspect","text":"Machines look for cracks, thin spots and bad finishes. Rejects are crushed and go back into the furnace as cullet.","inputs":[]}],"facts":["Press-and-blow is mainly used for jars, while blow-and-blow is the usual method for bottles.","A modern glass-forming machine can make more than 600 containers a minute.","Pressing the first stage controls how the glass spreads through the wall better than blowing it does."],"where":[],"whereNote":null,"sources":[{"title":"Container Glass Forming Process","url":"https://eurotherm.com/pt-br/glass-manufacture/container-glass-forming-process"},{"title":"Mason jar","url":"https://en.wikipedia.org/wiki/Mason_jar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"marble-toy","name":"Glass marble","kind":"product","category":"minerals","title":"How glass marbles are made","url":"https://assemblyline.org/make/marble-toy","stations":5,"upstream":16,"downstream":0,"depth":5,"dek":"A machine-made marble is rounded between two turning screws while it cools.","answer":"Machine-made glass marbles start as globules of molten glass dropped into a groove between two interlocking parallel screws. As the screws turn, the marble rolls along and is shaped into a sphere while it cools. Color comes from extra streams of colored glass blended into the main stream before the globule is cut.","aka":["glass marble","toy marble","cat's-eye marble"],"inputs":["silica-sand","soda-ash","limestone"],"uses":[],"grounds":["silica-sand","limestone","rock-salt","water","trona","natural-gas","air","corn","sugarcane","sugar-beet"],"upstreamSlugs":["silica-sand","soda-ash","limestone","rock-salt","water","ammonia","carbon-dioxide","lime","trona","natural-gas","air","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Melt the glass","process":"melt","text":"The base glass is a clear soda-lime batch of sand, soda ash and limestone melted in a furnace.","inputs":["silica-sand","soda-ash","limestone"]},{"name":"Stream in the color","process":"mix","text":"Color is added to the main batch glass and to extra glass streams that merge with the main stream in different ways. In the cat's-eye style, colored glass veins are injected into a clear stream. Colored glass may also be applied to the surface of cheaper clear or white glass.","inputs":[]},{"name":"Drop globules into the groove","process":"cut","text":"Blades chop the stream into globules, and each globule falls into a groove made by two interlocking parallel screws.","inputs":[]},{"name":"Roll it round between screws","process":"roll","text":"As the screws rotate, the marble travels along them. It is gradually shaped into a sphere as it cools.","inputs":[]},{"name":"Cool and sort","process":"inspect","text":"The cooled marbles are sorted for size and flaws and bagged. Sizes usually range from about 0.5 to 3.5 cm across.","inputs":[]}],"facts":["Vacor de Mexico makes 90 percent of the world's marbles, over 12 million a day.","In 1903, Martin Frederick Christensen of Akron, Ohio, made the first machine-made glass marbles on his patented machine.","A German glassblower invented marble scissors, a device for making marbles, in 1846."],"where":[],"whereNote":null,"sources":[{"title":"Marbles","url":"https://en.wikipedia.org/wiki/Marbles"},{"title":"Glass","url":"https://en.wikipedia.org/wiki/Glass"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"glycerin","name":"Glycerin","kind":"material","category":"chemicals","title":"How glycerin is made","url":"https://assemblyline.org/make/glycerin","stations":6,"upstream":14,"downstream":7,"depth":4,"dek":"Glycerin is the sweet, syrupy backbone of every fat, and it is now a surplus byproduct of biodiesel.","answer":"Glycerin comes from fats and oils. When vegetable oil or animal fat is split with caustic soda or reacted with an alcohol, its three fatty acid tails come off and glycerin is left in the water. The watery glycerin is evaporated, distilled under vacuum and filtered to remove color and odor.","aka":["glycerol","glycerine"],"inputs":["palm-oil","vegetable-oil","caustic-soda","methanol"],"uses":["soap","toothpaste","sunscreen","chewing-gum","snow-globe","cough-syrup","gelatin-capsule"],"grounds":["oil-palm-fruit","water","soybeans","rapeseed","clay","rock-salt","natural-gas","crude-oil"],"upstreamSlugs":["palm-oil","vegetable-oil","caustic-soda","methanol","oil-palm-fruit","water","soybeans","rapeseed","hexane","clay","rock-salt","natural-gas","crude-oil","hydrogen"],"downstreamSlugs":["soap","toothpaste","sunscreen","chewing-gum","snow-globe","cough-syrup","gelatin-capsule"],"steps":[{"name":"Split the fat","process":"react","text":"Palm oil, other vegetable oils or tallow are reacted with sodium hydroxide, which breaks each fat molecule into soap and glycerol. Biodiesel plants use an alcohol such as methanol instead and split off glycerol the same way.","inputs":["palm-oil","vegetable-oil","caustic-soda","methanol"]},{"name":"Settle the layers","process":"separate","text":"After the reaction, the mixture is left to settle or spun in centrifuges. The heavier, glycerin-rich water drains away from the soap or biodiesel.","inputs":[]},{"name":"Evaporate off the water","process":"refine","text":"Water is boiled out of the crude glycerin in multiple-effect evaporators, which reuse steam. Salt and other impurities crystallize and are filtered off.","inputs":[]},{"name":"Distill it under vacuum","process":"refine","text":"Glycerol boils at a high temperature, so the distillation chamber is held under vacuum. Low pressure lets it vaporize without scorching.","inputs":[]},{"name":"Bleach and filter","process":"wash","text":"Activated carbon removes color and smell from the distilled liquid. The clear syrup is filtered once more.","inputs":[]},{"name":"Drum and tank it","process":"fill","text":"Glycerin is stored in tanks, drums or totes. Commercial glycerin sold as glycerine is typically about 95% pure.","inputs":[]}],"facts":["Since around 2010 there has been a large surplus of glycerol as a byproduct of biofuel production.","Triglycerides can be saponified with sodium hydroxide to give glycerol and a fatty sodium salt, which is soap."],"where":[],"whereNote":null,"sources":[{"title":"Glycerol","url":"https://en.wikipedia.org/wiki/Glycerol"},{"title":"Biodiesel","url":"https://en.wikipedia.org/wiki/Biodiesel"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gold","name":"Gold","kind":"material","category":"metals","title":"How gold is made","url":"https://assemblyline.org/make/gold","stations":6,"upstream":11,"downstream":39,"depth":3,"dek":"In most gold mines the gold is invisible, and a ton of ore may hold only a few grams of it.","answer":"Gold is dug from rock that holds only a few parts per million of it. The ore is ground to a slurry and mixed with a dilute cyanide solution, which dissolves the gold. Activated carbon or zinc dust pulls the gold back out of the liquid, and furnaces melt it into bars that are refined to high purity.","aka":["gold bullion","refined gold","fine gold"],"inputs":["gold-ore","water","lime","zinc","chlorine"],"uses":["microchip","led","needle","gold-ring","fountain-pen","gold-bar","medal","smoke-detector","usb-cable"],"grounds":["gold-ore","water","limestone","zinc-ore","air","rock-salt","sulfur"],"upstreamSlugs":["gold-ore","water","lime","zinc","chlorine","limestone","zinc-ore","air","sulfuric-acid","rock-salt","sulfur"],"downstreamSlugs":["microchip","led","needle","gold-ring","fountain-pen","gold-bar","medal","smoke-detector","usb-cable","hearing-aid","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","rocket","smartwatch","wireless-earbuds","phone-charger","digital-camera","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","led-bulb","lcd-screen","pinball-machine","car"],"steps":[{"name":"Dig the ore","process":"mine","text":"Open pits typically yield 1 to 5 parts per million of gold, and underground mines at least 3. Ore as low as 0.5 parts per million can pay. Gold becomes visible to the naked eye only at around 30 parts per million.","inputs":["gold-ore"]},{"name":"Grind it to a slurry","process":"crush","text":"Grinding mills reduce the rock to fine particles, and water is added to turn it into a pulp. Some ores are first concentrated by froth flotation or by gravity.","inputs":["water"]},{"name":"Dissolve the gold in cyanide","process":"react","text":"Sodium cyanide solution is mixed into the pulp, and with oxygen present the gold dissolves as a soluble complex. Lime holds the slurry strongly alkaline, at a pH above 10.5, so that the cyanide stays in solution rather than escaping as gas.","inputs":["lime"]},{"name":"Capture it on carbon or zinc","process":"separate","text":"Gold is pulled out of the liquid by adsorbing it onto activated carbon. In the older Merrill-Crowe process, zinc dust and a vacuum precipitate it instead. What is left of the cyanide in the waste stream is treated to break it down.","inputs":["zinc"]},{"name":"Melt it into bars","process":"melt","text":"The recovered gold is smelted in a furnace and poured into rough bars, which still hold some other metals.","inputs":[]},{"name":"Refine it to purity","process":"refine","text":"Refiners use the Miller process, where chlorine gas is bubbled through the melt, or the Wohlwill process, which uses electrolysis and gives higher purity. Bullion coins can be 99.99 percent gold.","inputs":["chlorine"]}],"facts":["A single gram of gold can be beaten into a sheet of 1 square meter.","Around 201,296 tonnes of gold exist above ground, which would fit into a cube 21.7 meters on a side.","Recycling a kilogram of gold produces 53 kilograms of CO2 equivalent, while mining a kilogram produces 16 tonnes."],"where":[{"place":"China","share":"380 metric tons"},{"place":"Russia","share":"310 metric tons"},{"place":"Australia","share":"280 metric tons"},{"place":"Canada","share":"200 metric tons"},{"place":"United States","share":"160 metric tons"}],"whereNote":"2025, gold mined.","sources":[{"title":"Gold","url":"https://en.wikipedia.org/wiki/Gold"},{"title":"Gold cyanidation","url":"https://en.wikipedia.org/wiki/Gold_cyanidation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gold-bar","name":"Gold bar","kind":"product","category":"hardware","title":"How gold bars are made","url":"https://assemblyline.org/make/gold-bar","stations":6,"upstream":12,"downstream":0,"depth":4,"dek":"The big bars in central bank vaults weigh about 12.4 kilograms and are poured, not stamped.","answer":"Refined gold, commonly 99.99% pure, is melted and poured into a mold, where it cools into a cast bar with rounded edges. The bar is cleaned, weighed and inspected before its maker, weight, purity and serial number are stamped on. Minted bars take another route: molten gold becomes a long flat strip, blanks are cut from it, and engraved dies strike each one under high pressure.","aka":["gold ingot","bullion bar"],"inputs":["gold"],"uses":[],"grounds":["gold-ore","water","limestone","zinc-ore","air","rock-salt","sulfur"],"upstreamSlugs":["gold","gold-ore","water","lime","zinc","chlorine","limestone","zinc-ore","air","sulfuric-acid","rock-salt","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Melt refined gold","process":"melt","text":"Gold from mines or recycling, refined to at least 99.9% pure, is melted ready for casting.","inputs":["gold"]},{"name":"Pour into the mold","process":"cast","text":"Molten metal goes into bar-shaped molds and is left to cool. Some plants instead run it through a graphite die into a continuous strip, the starting point for minted bars.","inputs":[]},{"name":"Clean and weigh","process":"inspect","text":"The cooled bar is cleaned and weighed. Its surface keeps the individual marks of the pour.","inputs":[]},{"name":"Strike the minted blanks","process":"press","text":"Blanks cut to exact size from a flat strip go between engraved dies, which strike them under high pressure and leave crisp detail.","inputs":[]},{"name":"Stamp the marks","process":"stamp","text":"Manually or on an industrial press, the bar gets the maker's hallmark, weight, purity and often a unique serial number.","inputs":[]},{"name":"Assay and seal","process":"package","text":"Weight, dimensions, purity and surface finish are verified. Many bars then go into tamper-evident packs with an assay certificate.","inputs":[]}],"facts":["The standard Good Delivery bar held by central banks has a nominal weight of 400 troy ounces, about 12.4 kilograms.","A Good Delivery bar must be at least 995 parts per thousand gold."],"where":[],"whereNote":null,"sources":[{"title":"156Bullion: How are gold bars made?","url":"https://156bullion.co.uk/blogs/news/how-are-gold-bars-made-from-refinery-to-finished-bar-156bullion"},{"title":"Delmer Group: How cast gold bars are made","url":"https://delmergroup.com/en-us/blogs/news/how-cast-gold-bars-are-made-the-craft-behind-investment-bullion"},{"title":"Gold bar","url":"https://en.wikipedia.org/wiki/Gold_bar"},{"title":"Gold","url":"https://en.wikipedia.org/wiki/Gold"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gold-ore","name":"Gold ore","kind":"raw","category":"ground","title":"How gold ore is mined","url":"https://assemblyline.org/make/gold-ore","stations":4,"upstream":0,"downstream":40,"depth":0,"dek":"Because gold is soft and heavy, a stream of water can separate it from gravel with no chemistry at all.","answer":"Gold is recovered two ways. Placer mines work loose gravel in river beds, where gold has settled because it is far heavier than the sand around it, and water carries the light material away. Hard-rock mines crush gold-bearing rock, and most of it is then dissolved out with a cyanide solution.","aka":["placer gold","gold bearing rock"],"inputs":[],"uses":["gold"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["gold","microchip","led","needle","gold-ring","fountain-pen","gold-bar","medal","smoke-detector","usb-cable","hearing-aid","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","rocket","smartwatch","wireless-earbuds","phone-charger","digital-camera","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","led-bulb","lcd-screen","pinball-machine","car"],"steps":[{"name":"Dig rock or gravel","process":"mine","text":"Conventional mines remove gold-bearing rock from pits or tunnels. Placer mines instead work loose river gravel, the kind of ground the Klondike and Australian gold rushes were fought over.","inputs":[]},{"name":"Screen out the boulders","process":"separate","text":"Large commercial placer operations run gravel through rotating screens called trommels, which throw out boulders and cobbles. Hard rock is crushed to free the gold from the stone around it.","inputs":[]},{"name":"Let gravity sort it","process":"separate","text":"Gravel flows through a sluice box with ridges across its floor. Heavier particles sink and lodge behind the ridges while lighter sand is carried off downstream. Jigs do the same job by pulsing water through a bed of material.","inputs":[]},{"name":"Dissolve it from the powder","process":"wash","text":"Most hard-rock gold is recovered by cyanidation, introduced in the late 1800s. A cyanide solution forms a stable complex with the gold, pulling it out of the crushed ore. The method is highly toxic, so the water has to be tightly managed.","inputs":[]}],"facts":["Gold mining dates back to at least 4700 BC.","The Australian gold rushes began in 1851 when Edward Hargraves discovered gold near Bathurst, New South Wales.","Cyanide forms such stable complexes with gold that it became the dominant way to recover it, from the late 1800s on."],"where":[{"place":"China","share":"380 tonnes"},{"place":"Russia","share":"310 tonnes"},{"place":"Australia","share":"290 tonnes"}],"whereNote":"Gold mined in the latest year given in the Gold mining article; world production was 3,612 tonnes in 2022.","sources":[{"title":"Gold mining","url":"https://en.wikipedia.org/wiki/Gold_mining"},{"title":"Placer deposit","url":"https://en.wikipedia.org/wiki/Placer_deposit"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gold-ring","name":"Gold ring","kind":"product","category":"hardware","title":"How gold rings are made","url":"https://assemblyline.org/make/gold-ring","stations":8,"upstream":22,"downstream":0,"depth":4,"dek":"Pure gold is so soft that a wedding band is mixed with copper or silver before it is made.","answer":"Most gold rings are lost-wax cast. Wax is injected into a rubber mold of a master ring, and the waxes join on a tree inside a cylinder, which is filled with fine plaster and vacuumed free of air. A kiln melts the wax out. Molten gold fills the ring-shaped cavity, and the hot cylinder is quenched to wash the plaster away.","aka":["wedding band","gold band"],"inputs":["gold","copper","silver","beeswax","plaster"],"uses":[],"grounds":["gold-ore","water","copper-ore","air","silver-ore","lead-ore","zinc-ore","honeycomb","gypsum","limestone","rock-salt","sulfur"],"upstreamSlugs":["gold","copper","silver","beeswax","plaster","gold-ore","water","lime","zinc","chlorine","copper-ore","oxygen","air","sulfuric-acid","silver-ore","lead-ore","zinc-ore","honeycomb","gypsum","limestone","rock-salt","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Alloy the gold","process":"melt","text":"Pure gold is too soft, so it is melted with other metals to the chosen karat. The mix of gold with copper or silver sets the color and hardness.","inputs":["gold","copper","silver"]},{"name":"Inject the wax","process":"mold","text":"Rubber layers cured around a master model make a mold. Wax is injected into it, hardens and comes out as a ring form, ready to be inspected for flaws.","inputs":["beeswax"]},{"name":"Build a wax tree","process":"assemble","text":"Wax rings attach to a sprue, which later becomes the channel for metal, and several can share one tree so a batch casts at once. The tree stands in a cylinder.","inputs":[]},{"name":"Pour the investment","process":"cast","text":"A very high grade casting plaster, called investment, fills the cylinder and covers the wax. A vacuum takes out the air, since any bubble would spoil the casting.","inputs":["plaster"]},{"name":"Burn out the wax","process":"fire","text":"Over several hours in a kiln, the plaster hardens and wax melts away. What remains is a ring-shaped cavity.","inputs":[]},{"name":"Cast the metal","process":"cast","text":"The hard mold goes in a casting machine and fills with molten alloy. Once set, the hot cylinder is plunged into water, and the plaster washes out.","inputs":[]},{"name":"Fix any setting","process":"assemble","text":"The rough ring is cut from its tree and cleaned up, and stones or settings are added where the design has them.","inputs":[]},{"name":"Polish and hallmark","process":"grind","text":"The ring is polished until smooth, inspected by a goldsmith and hallmarked.","inputs":[]}],"facts":["Gold is the most malleable metal, and it can be drawn into a wire one atom wide.","Rose gold of 18 karats gets its color from added copper.","As of 2020 around 201,296 tonnes of gold existed above ground, enough to make a cube about 21.7 meters on each side."],"where":[],"whereNote":null,"sources":[{"title":"Market Square Jewelers: The jewelry casting process, lost-wax casting","url":"https://marketsquarejewelers.com/blogs/msj-handbook/the-jewelry-casting-process-lost-wax-casting"},{"title":"F.Hinds: Plain gold fitted wedding ring","url":"https://www.fhinds.co.uk/design-service/Plain-Gold-Fitted-Wedding-Ring"},{"title":"Ring (jewellery)","url":"https://en.wikipedia.org/wiki/Ring_(jewellery)"},{"title":"Gold","url":"https://en.wikipedia.org/wiki/Gold"},{"title":"Lost-wax casting","url":"https://en.wikipedia.org/wiki/Lost-wax_casting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"golf-ball","name":"Golf ball","kind":"product","category":"play","title":"How golf balls are made","url":"https://assemblyline.org/make/golf-ball","stations":8,"upstream":65,"downstream":0,"depth":10,"dek":"Golf balls are dimpled because players noticed that scuffed, nicked balls flew better than smooth ones.","answer":"A modern golf ball has a molded rubber core, often with one or more layers around it, and a thin plastic cover. The core is pressed and heated in a mold, then covered with a tough urethane or ionomer shell. The cover mold carries a pattern of dimples. The ball is trimmed, painted and printed.","aka":["golf ball","two-piece ball","urethane ball"],"inputs":["synthetic-rubber","polyurethane","paint","ink"],"uses":[],"grounds":["water","crude-oil","natural-gas","air","rock-salt","titanium-ore","iron-ore","sulfur","soybeans","rapeseed","clay","corn","sugarcane","coal","tin-ore","sugar-beet","limestone","dolomite","manganese-ore","quartz","timber"],"upstreamSlugs":["synthetic-rubber","polyurethane","paint","ink","naphtha","benzene","ethylene","styrene","water","propylene","nitric-acid","chlorine","titanium-dioxide","pigment","acrylic","tin-can","vegetable-oil","phenolic-resin","carbon-black","ethanol","crude-oil","hydrogen","toluene","natural-gas","ammonia","air","rock-salt","sulfuric-acid","titanium-ore","coke","oxygen","iron-ore","sulfur","methanol","tinplate","lacquer","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","corn","sugarcane","yeast","coal","steel","tin","molasses","pig-iron","magnesium","steel-scrap","lime","manganese","argon","tin-ore","sugar-beet","limestone","dolomite","silicon","propane","manganese-ore","quartz","charcoal","timber"],"downstreamSlugs":[],"steps":[{"name":"Mix the core rubber","process":"mix","text":"Synthetic rubber is blended with additives into a dough, which is cut into slugs sized for one core each.","inputs":["synthetic-rubber"]},{"name":"Press and heat the cores","process":"mold","text":"Slugs are squeezed in a mold under heat, curing into a hard, bouncy sphere. Balls with more layers are two-piece, three-piece or four-piece.","inputs":[]},{"name":"Add a middle layer","process":"mold","text":"Premium balls get a mantle between core and cover, which is molded around the core in a second step. A two-piece ball skips this.","inputs":["polyurethane"]},{"name":"Mold the dimpled cover","process":"mold","text":"The core is placed in a mold with a pattern of dimples, and a plastic cover flows around it. Common cover plastics are ionomers and urethane.","inputs":["polyurethane"]},{"name":"Trim and buff","process":"grind","text":"The seam where the mold halves met is ground off, and the surface is smoothed.","inputs":[]},{"name":"Paint and clear-coat","process":"coat","text":"Balls are primed, painted white or another color, and covered with a clear coat. Dimples must stay sharp.","inputs":["paint"]},{"name":"Print the logo","process":"print","text":"Brand names and numbers are pad-printed on and sealed.","inputs":["ink"]},{"name":"Weigh and check","process":"inspect","text":"Balls are checked for size and mass. Under the rules, a ball can weigh no more than 45.93 g and be no smaller than 42.67 mm across.","inputs":[]}],"facts":["Early golf balls were leather pouches stuffed with boiled feathers, and an experienced maker could finish only a few in a day.","The first liquid-filled balls had caustic cores, which injured children who cut them open, and makers dropped them by the 1920s."],"where":[],"whereNote":null,"sources":[{"title":"Golf ball","url":"https://en.wikipedia.org/wiki/Golf_ball"},{"title":"Ionomer (Surlyn)","url":"https://en.wikipedia.org/wiki/Surlyn"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"golf-club","name":"Golf club","kind":"product","category":"play","title":"How golf clubs are made","url":"https://assemblyline.org/make/golf-club","stations":10,"upstream":87,"downstream":0,"depth":10,"dek":"Most iron heads are cast from a wax copy of themselves, wrapped in sand and then melted out.","answer":"Most iron, hybrid and wedge heads are cast by the lost-wax method. A wax copy of the head is dipped in sand slurry to form a shell, then steamed out and replaced with molten steel. The shell is cracked off, the heads are cut from a metal tree, polished and checked for loft, the logos are painted in, and a shaft and grip go on.","aka":["iron","driver","golf iron","wood"],"inputs":["paraffin-wax","silica-sand","stainless-steel","paint","steel","carbon-fiber","adhesive","rubber"],"uses":[],"grounds":["silica-sand","crude-oil","water","air","natural-latex","sulfur","natural-gas","chromite","limestone","nickel-ore","titanium-ore","iron-ore","dolomite","manganese-ore","coal","rock-salt","trona","quartz","timber","corn","bauxite","tin-ore","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["paraffin-wax","silica-sand","stainless-steel","paint","steel","carbon-fiber","adhesive","rubber","crude-oil","hydrogen","steel-scrap","chromium","nickel","oxygen","argon","water","titanium-dioxide","pigment","acrylic","tin-can","pig-iron","magnesium","lime","manganese","propylene","ammonia","air","polyethylene","epoxy","polyurethane","natural-latex","synthetic-rubber","carbon-black","sulfur","natural-gas","propane","chromite","coke","soda-ash","limestone","aluminum","nickel-ore","sulfuric-acid","titanium-ore","chlorine","iron-ore","methanol","tinplate","lacquer","ink","dolomite","silicon","manganese-ore","naphtha","ethylene","phenol","acetone","caustic-soda","nitric-acid","benzene","styrene","coal","rock-salt","carbon-dioxide","trona","petroleum-coke","alumina","tin","ethanol","vegetable-oil","phenolic-resin","quartz","charcoal","timber","toluene","corn","yeast","bauxite","tin-ore","sugarcane","soybeans","rapeseed","hexane","clay","formaldehyde","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Inject a wax copy","process":"mold","text":"A computer-designed metal mold, a mirror image of the head, is clamped in a machine that squirts in hot wax. Every head needs its own wax copy.","inputs":["paraffin-wax"]},{"name":"Trim the wax by hand","process":"grind","text":"Each wax head is checked for blemishes, and a fine file removes stray bits. Any flaw on the wax will show up in the finished steel head.","inputs":[]},{"name":"Dip the tree in sand","process":"coat","text":"Wax heads are melted onto a wax tree in groups of 14 and dipped in sand slurry. Each layer dries in a cold room and the dipping is repeated five times, until the shell can survive molten metal.","inputs":["silica-sand"]},{"name":"Steam out the wax","process":"melt","text":"The shell goes into a steam oven, and the wax melts out from inside. The top of the tree is shaped like a funnel so metal can be poured in.","inputs":[]},{"name":"Pour the molten steel","process":"cast","text":"A stainless alloy is heated to 1500 degrees Celsius. The shells, kept at the same temperature, are carried from the furnace to the pouring station, filled, and set on a bed of sand to harden.","inputs":["stainless-steel"],"spec":"1500 °C"},{"name":"Crack off the shell","process":"cut","text":"The sand shell is knocked away, leaving rough heads still joined to the tree. A metal cutter then trims each one off.","inputs":[]},{"name":"Polish and sandblast","process":"grind","text":"Heads are polished and the face is sandblasted to give it some grip on the ball.","inputs":[]},{"name":"Check loft and weight","process":"inspect","text":"Loft, lie, weight and hosel diameter are measured against the maker's tolerances and the limits set by the R&A, which governs the rules of golf.","inputs":[]},{"name":"Paint the logos and score lines","process":"coat","text":"The logos and score lines are part of the original mold, but they must be colored in by hand before the head is ready to sell.","inputs":["paint"]},{"name":"Bond on shaft and grip","process":"assemble","text":"A steel or graphite shaft is fixed into the hosel, the socket on the head, with adhesive. A rubber grip goes on the other end, and the club is ready to sell.","inputs":["steel","carbon-fiber","adhesive","rubber"]}],"facts":["Premium forged irons start as a bar of mild iron heated to 1200 degrees Celsius, then are struck several times by a forging hammer.","Each casting destroys its own wax pattern, so every club needs a new wax head.","A set of 9 irons needs 9 different wax molds, one for each loft."],"where":[],"whereNote":null,"sources":[{"title":"How Golf Clubs Are Made (The Casting Process)","url":"https://mygolfspy.com/news-opinion/how-golf-clubs-are-made-cast-proces/"},{"title":"How Golf Clubs Are Made (The Forging Process)","url":"https://mygolfspy.com/how-golf-clubs-are-made/"},{"title":"Golf club","url":"https://en.wikipedia.org/wiki/Golf_club"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"granite","name":"Granite","kind":"raw","category":"ground","title":"How granite is quarried","url":"https://assemblyline.org/make/granite","stations":3,"upstream":0,"downstream":1,"depth":0,"dek":"Granite is magma that cooled so slowly underground that its crystals grew big enough to see.","answer":"Granite is a coarse-grained rock of quartz, feldspar and mica that formed when silica-rich magma cooled slowly deep underground. Quarries cut massive blocks out of exposed rock. The blocks are sawn into slabs, which are polished into countertops, building facing and monuments, or crushed into aggregate.","aka":["building granite","dimension granite"],"inputs":[],"uses":["kitchen-countertop"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["kitchen-countertop"],"steps":[{"name":"Cut the block free","process":"mine","text":"Quarry crews drill and split large blocks out of the granite mass. Blasting is kept gentle for dimension stone, because heavy blasting shatters the rock and ruins it for slabs.","inputs":[]},{"name":"Saw into slabs","process":"cut","text":"Gang saws slice blocks into big slabs. Slabs for monuments can be up to 3 meters wide and over 150 millimeters thick before smaller saws shape them.","inputs":[]},{"name":"Polish the face","process":"grind","text":"Slabs for countertops are polished, and sometimes honed or sandblasted instead. Standard countertop slabs in the United States are 19 or 32 millimeters thick.","inputs":[]}],"facts":["The word granite comes from the Latin granum, a grain, for its coarse crystals.","The Brihadeeswarar Temple in India, built in 1010, is credited as the world's first temple built entirely of granite.","Imperial Roman granite was quarried mainly in Egypt, and the quarrying ceased around the third century AD."],"where":[],"whereNote":null,"sources":[{"title":"Granite","url":"https://en.wikipedia.org/wiki/Granite"},{"title":"Dimension stone","url":"https://en.wikipedia.org/wiki/Dimension_stone"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"kitchen-countertop","name":"Granite countertop","kind":"product","category":"minerals","title":"How granite countertops are made","url":"https://assemblyline.org/make/kitchen-countertop","stations":6,"upstream":1,"downstream":0,"depth":1,"dek":"A kitchen slab is a sliver of rock that cooled slowly underground, cut and polished to just 19 or 32 mm thick.","answer":"A granite countertop starts as a big block cut from a quarry with diamond wire saws. The block is sawn into slabs 19 or 32 mm thick, and the slabs are polished. A fabricator then cuts each slab to the kitchen layout, shapes the edges and sink cutouts with routers and CNC machines, and seals the stone.","aka":["granite counter","stone countertop","kitchen worktop"],"inputs":["granite"],"uses":[],"grounds":["granite"],"upstreamSlugs":["granite"],"downstreamSlugs":[],"steps":[{"name":"Cut a block from the hill","process":"mine","text":"Dimension stone quarries separate blocks with diamond wire saws, diamond belt saws or light, selective blasting. Heavy blasting would shatter the stone.","inputs":["granite"]},{"name":"Saw it into slabs","process":"cut","text":"Gang saws slice the block into slabs. Standard thicknesses in the United States are 19 and 32 mm, and thin slabs are sometimes laminated at the edge to look thicker.","inputs":[],"spec":"19 or 32 mm thick"},{"name":"Polish the face","process":"grind","text":"Abrasives give the slab a polished finish with high luster and a near-mirror reflection. Some countertops are left honed, a satin finish with no reflection.","inputs":[]},{"name":"Cut to the kitchen plan","process":"cut","text":"A fabricator shapes the slab to the kitchen layout using cutting and finishing equipment. Holes for sinks and cooktops are cut at this stage.","inputs":[]},{"name":"Shape the edges","process":"machine","text":"Edges are cut with hand-held routers, grinders or CNC equipment. Stone with a strong pattern may be laid out in the shop so the customer can inspect it first.","inputs":[]},{"name":"Seal the stone","process":"coat","text":"Natural stone needs sealing so it does not hold bacteria or stain. Newer oleophobic impregnators have reduced how often it needs to be resealed.","inputs":[]}],"facts":["Granite is a coarse-grained igneous rock of quartz, feldspar and mica that cooled slowly from magma underground.","Some fabrication is done at the quarry, with blocks sawn to thickness and polished there, which saves shipping waste."],"where":[],"whereNote":null,"sources":[{"title":"Countertop","url":"https://en.wikipedia.org/wiki/Countertop"},{"title":"Dimension stone","url":"https://en.wikipedia.org/wiki/Dimension_stone"},{"title":"Granite","url":"https://en.wikipedia.org/wiki/Granite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"granola-bar","name":"Granola bar","kind":"product","category":"food","title":"How granola bars are made","url":"https://assemblyline.org/make/granola-bar","stations":6,"upstream":8,"downstream":0,"depth":3,"dek":"A granola bar is cereal glued into a slab with syrup, pressed flat and cut into bars.","answer":"Rolled oats, nuts, seeds and sometimes puffed rice are mixed with honey or other sweet syrup, which acts as glue. The sticky mixture is pressed into a slab and baked. After cooling, the slab is cut into bars and each bar is wrapped. Granola itself is oats baked with oil and stirred until crisp.","aka":["muesli bar","cereal bar","oat bar"],"inputs":["oatmeal","honey","corn-syrup"],"uses":[],"grounds":["oats","honeycomb","corn","water"],"upstreamSlugs":["oatmeal","honey","corn-syrup","oats","honeycomb","corn","corn-starch","water"],"downstreamSlugs":[],"steps":[{"name":"Weigh the dry mix","process":"mix","text":"Rolled oats, nuts, seeds and sometimes puffed rice are blended. Dried fruit and chocolate pieces may go in too.","inputs":["oatmeal"]},{"name":"Coat with syrup","process":"mix","text":"Honey, corn syrup or maple syrup is stirred through the dry mix. The syrup is what holds the pieces together once it cools.","inputs":["honey","corn-syrup"]},{"name":"Press into a mold","process":"press","text":"The sticky mix is pressed into molds or a flat, even slab. Pressure matters, because loose granola crumbles instead of staying a bar.","inputs":[]},{"name":"Bake until set","process":"bake","text":"An oven toasts the mix and sets the syrup. Time and temperature change with the recipe, and the bars then cool to room temperature.","inputs":[]},{"name":"Slice the slab","process":"cut","text":"Blades cut the cooled slab into individual bars of equal size.","inputs":[]},{"name":"Wrap each bar","process":"package","text":"Bars are wrapped one by one and boxed, ready for lunch boxes and backpacks.","inputs":[]}],"facts":["The first granola, called granula, was invented in 1863 by James Caleb Jackson in Dansville, New York.","In 1969 at Woodstock, volunteers fed about 130,000 people from Dixie cups of muesli.","The invention of the granola bar is disputed between two US inventors, though most of the credit goes to Stanley Mason."],"where":[],"whereNote":null,"sources":[{"title":"Granola bar","url":"https://en.wikipedia.org/wiki/Granola_bar"},{"title":"Rolled oats","url":"https://en.wikipedia.org/wiki/Rolled_oats"},{"title":"Snack bars","url":"https://bakerpedia.com/processes/snack-bars/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"graphics-card","name":"Graphics card","kind":"product","category":"electronics","title":"How graphics cards are made","url":"https://assemblyline.org/make/graphics-card","stations":7,"upstream":89,"downstream":0,"depth":9,"dek":"A graphics card is a second computer, with its own processor and memory, built to draw millions of pixels at once.","answer":"A graphics card is a circuit board built around a graphics processing unit and memory chips. Solder is screen-printed onto the board and surface-mount machines place the chips, then larger through-hole parts go in by hand and pass a wave soldering machine. A heat sink, fans and a bracket are fitted, the BIOS is loaded, and every card is tested.","aka":["GPU","video card","graphics processing unit"],"inputs":["microchip","printed-circuit-board","solder","memory-chip","aluminum","copper","abs-plastic","electric-motor","screw"],"uses":[],"grounds":["crude-oil","coal","copper-ore","water","air","quartz","tin-ore","gold-ore","silica-sand","limestone","lead-ore","silver-ore","zinc-ore","bauxite","sulfur","natural-gas","iron-ore","rock-salt","trona","titanium-ore","dolomite","manganese-ore","timber","corn","sugarcane","sugar-beet"],"upstreamSlugs":["microchip","printed-circuit-board","solder","memory-chip","aluminum","copper","abs-plastic","electric-motor","screw","silicon-wafer","oxygen","photoresist","tin","gold","fiberglass","epoxy","lead","silver","nitrogen","crude-oil","coal","petroleum-coke","alumina","copper-ore","water","air","sulfuric-acid","naphtha","propylene","ammonia","benzene","ethylene","styrene","pigment","sheet-steel","copper-wire","ball-bearing","steel","steel-wire","zinc","polysilicon","quartz","argon","phenolic-resin","tin-ore","coke","gold-ore","lime","chlorine","silica-sand","limestone","soda-ash","phenol","acetone","caustic-soda","lead-ore","silver-ore","zinc-ore","bauxite","sulfur","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","carbon-black","pig-iron","magnesium","steel-scrap","manganese","silicon","hydrochloric-acid","trichlorosilane","formaldehyde","rock-salt","carbon-dioxide","trona","titanium-ore","dolomite","propane","manganese-ore","charcoal","timber","methanol","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Fabricate the graphics chip","process":"etch","text":"The GPU is patterned on a silicon wafer, repeating light exposure and etching to build billions of transistors. The wafer is cut into chips that are tested and sorted.","inputs":["microchip"]},{"name":"Print the solder","process":"print","text":"Solder paste goes onto the multilayer board through a screen, much as ink goes onto a T-shirt. It lands only on the pads where parts will sit.","inputs":["printed-circuit-board","solder"]},{"name":"Place chips and memory","process":"assemble","text":"Surface-mount machines fed from spools set the GPU, memory chips and power parts on the board, and an oven melts the solder so every joint forms at once.","inputs":["memory-chip"]},{"name":"Add through-hole parts","process":"weld","text":"Coarser parts such as connectors are placed by hand. The boards then ride a belt through a wave soldering machine, which solders everything in one pass, and a cooling unit brings them down.","inputs":["solder"]},{"name":"Build the heat sink","process":"extrude","text":"Aluminum is extruded or stacked into fins, and copper heat pipes are pressed in. The pipes carry heat away from the GPU to the fins, where fans blow it out.","inputs":["aluminum","copper"]},{"name":"Fit fans and shroud","process":"assemble","text":"Plastic fans and a shroud are screwed over the heat sink. The shroud is molded plastic that guides air through the fins.","inputs":["abs-plastic","electric-motor","screw"]},{"name":"Load the BIOS and test","process":"inspect","text":"Each card has its BIOS loaded and runs a set of graphics tests. A card that passes goes back to the line for packaging, and one that fails goes to an engineer.","inputs":[]}],"facts":["One Zotac plant in Dongguan produces an average of 400,000 graphics cards a month.","Nvidia's RIVA 128, released in 1997, was one of the first consumer chips to combine 2D and 3D processing on a single chip."],"where":[],"whereNote":null,"sources":[{"title":"Graphics card","url":"https://en.wikipedia.org/wiki/Graphics_card"},{"title":"Zotac factory tour in Dongguan (Think Computers)","url":"https://thinkcomputers.org/zotac-factory-tour-in-dongguan-china/"},{"title":"Gigabyte factory photo tour (HW Cooling)","url":"https://www.hwcooling.net/en/gigabyte-factory-photo-tour-mobo-and-graphics-cards-production/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gravel","name":"Gravel and crushed stone","kind":"raw","category":"ground","title":"How gravel and crushed stone are made","url":"https://assemblyline.org/make/gravel","stations":3,"upstream":0,"downstream":5,"depth":0,"dek":"Almost half of all gravel production goes into concrete as aggregate.","answer":"Gravel is loose rock between 2 and 64 millimeters or so, laid down by rivers and glaciers. It is dug from pits and river flood plains. Crushed stone is made instead by blasting solid rock and breaking it in crushers. Both are screened by size and used in concrete and under roads.","aka":["aggregate","crushed stone","crusher run"],"inputs":[],"uses":["asphalt","concrete","road","roof-shingle"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["asphalt","concrete","road","roof-shingle","skyscraper"],"steps":[{"name":"Dig the river deposit","process":"mine","text":"Natural gravel sits in stream channels, river flood plains and glacial deposits. Excavators and dredges lift it out together with its sand and clay.","inputs":[]},{"name":"Crush solid rock","process":"crush","text":"Where natural gravel is scarce, quarries blast granite, limestone or dolomite and feed it into crushers. The pieces are angular, and they lock together under a road.","inputs":[]},{"name":"Screen by size","process":"separate","text":"Screens sort the material into grades, from fine to coarse. Crushed and graded stone may be blended with fines for surfacing roads and driveways.","inputs":[]}],"facts":["Quartz is the most common mineral in gravel, because it is hard, chemically inert and lacks cleavage planes.","In 2020, sand and gravel together made up 23% of all industrial mineral production in the United States."],"where":[],"whereNote":null,"sources":[{"title":"Gravel","url":"https://en.wikipedia.org/wiki/Gravel"},{"title":"Crushed stone","url":"https://en.wikipedia.org/wiki/Crushed_stone"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"green-tea","name":"Green tea","kind":"product","category":"drink","title":"How green tea is made","url":"https://assemblyline.org/make/green-tea","stations":7,"upstream":1,"downstream":0,"depth":1,"dek":"The difference between green and black tea is heat: green tea is cooked within hours of picking to stop the leaf from browning.","answer":"Green tea is made from leaves that are heated almost immediately after picking, by steam in Japan or by pan-frying in China. The heat deactivates the enzymes that would turn the leaf brown. The leaves are then rolled to shape, dried, and often given a final firing before being sorted, blended and packed.","aka":["sencha","matcha leaf","longjing"],"inputs":["tea-leaves"],"uses":[],"grounds":["tea-leaves"],"upstreamSlugs":["tea-leaves"],"downstreamSlugs":[],"steps":[{"name":"Pick the fresh shoots","process":"harvest","text":"Bushes are pruned in rows to send up even shoots, and the crop is harvested three times a year in many places. Processing starts within one to two days of picking.","inputs":["tea-leaves"]},{"name":"Heat to halt browning","process":"cook","text":"Leaves are steamed, as in Japan, or tossed in a hot dry wok or rolling drum, as in China. This step, called fixation, kills the enzymes that would otherwise oxidize the leaf. Steaming gives a sweeter, grassier cup.","inputs":[]},{"name":"Roll and twist","process":"knead","text":"Leaves are rolled by hand or between machine plates. Rolling twists them into thin needles or small pellets and releases some juice and oils from inside.","inputs":[]},{"name":"Dry to a crisp","process":"dry","text":"Warm air or heated pans drive off the remaining water. Methods include oven-drying, tumble-drying and basket firing.","inputs":[]},{"name":"Chill the rough tea","process":"chill","text":"Japanese rough tea, called aracha, is stored under low humidity in cold stores. It is kept in paper bags at 0 to 5 °C until it is finished.","inputs":[],"spec":"0–5 °C in 30 or 60 kilogram bags"},{"name":"Final fire and sort","process":"bake","text":"A last firing develops the flavor and dries the leaf fully. Stems and flakes are removed to refine the aracha.","inputs":[]},{"name":"Blend the batches","process":"mix","text":"Most Japanese tea is blended from leaves grown in different regions. The blend is chosen for a consistent taste before packing.","inputs":[]}],"facts":["Gunpowder tea gets its name because each leaf is tumble-dried into a small pellet that resembles gunpowder.","Sencha is 80% of all tea made in Japan, and 90% of it comes from a single cultivar, Yabukita.","Chinese green tea was originally steamed, but after the early Ming dynasty it was typically pan-fired in a dry wok."],"where":[{"place":"China","share":"about 80% of the green tea market"}],"whereNote":"2015, share of the world green tea market as reported on Wikipedia.","sources":[{"title":"Green tea","url":"https://en.wikipedia.org/wiki/Green_tea"},{"title":"Tea processing","url":"https://en.wikipedia.org/wiki/Tea_processing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"guitar-string","name":"Guitar string","kind":"product","category":"play","title":"How guitar strings are made","url":"https://assemblyline.org/make/guitar-string","stations":6,"upstream":42,"downstream":0,"depth":6,"dek":"A wound guitar string is steel wire wrapped in a second wire, and its six-sided core gives the wrap something to grip.","answer":"A wound guitar string has a hexagonal high-carbon steel core and a wire coiled tightly around it. Machines spin the core while laying the wrap wire in an even spiral. For acoustic strings the wrap is phosphor bronze. In one patented method, heating the finished string relaxes stress in the winding and keeps the tone bright.","aka":["guitar strings","wound string","acoustic guitar strings"],"inputs":["steel-wire","bronze","brass"],"uses":[],"grounds":["copper-ore","water","air","tin-ore","zinc-ore","lead-ore","crude-oil","coal","iron-ore","limestone","dolomite","manganese-ore","natural-gas","sulfur","bauxite","quartz","timber","rock-salt"],"upstreamSlugs":["steel-wire","bronze","brass","steel","copper","tin","zinc","lead","aluminum","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","copper-ore","water","air","sulfuric-acid","tin-ore","coke","zinc-ore","lead-ore","crude-oil","coal","petroleum-coke","alumina","iron-ore","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","sulfur","bauxite","caustic-soda","quartz","charcoal","timber","rock-salt"],"downstreamSlugs":[],"steps":[{"name":"Draw the hex core","process":"draw","text":"High-carbon steel wire is drawn through a die so that it has six flat sides. The corners give the wrap wire something to grip.","inputs":["steel-wire"]},{"name":"Draw the wrap wire","process":"draw","text":"Wrap wire is drawn thin, in phosphor bronze for acoustic sets.","inputs":["bronze"]},{"name":"Fix on the ball end","process":"assemble","text":"Many strings end in a ball end, a short brass cylinder that anchors the string at the end opposite the tuning peg.","inputs":["brass"]},{"name":"Wind the wrap on","process":"spin","text":"A winding machine turns the core while the thinner wire is laid around it in a spiral along the length of the string. Round wire gives the familiar bumpy surface.","inputs":[]},{"name":"Heat to relax the stress","process":"heat-treat","text":"In one patented method, the finished string is held at an elevated temperature for a long time. This relieves stresses from the wrapping and evens out the spacing of the coils, so the string keeps its brilliance longer.","inputs":[]},{"name":"Coil and pack","process":"package","text":"Strings are inspected, coiled and sealed in an envelope or bag.","inputs":[]}],"facts":["Before the Second World War, strings for violins, lutes and guitars were mostly gut, often called catgut, though cats were never used as a source.","Round-wound strings squeak under the fingers because of their bumpy surface, which flat-wound strings greatly reduce.","D'Addario first put phosphor bronze into acoustic guitar strings in 1974."],"where":[],"whereNote":null,"sources":[{"title":"D'Addario Phosphor Bronze Acoustic Guitar Strings","url":"https://www.daddario.com/products/guitar/acoustic-guitar/phosphor-bronze/ej41-phosphor-bronze-12-string-acoustic-guitar-strings-extra-light-9-45/item/daddario-ej41-12-string-phosphor-bronze-acoustic-guitar-strings-extra-light-9-45-762"},{"title":"Method of making a wound musical instrument string","url":"https://patents.google.com/patent/US4063674"},{"title":"String (music)","url":"https://en.wikipedia.org/wiki/String_(music)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gummy-bears","name":"Gummy bears","kind":"product","category":"food","title":"How gummy bears are made","url":"https://assemblyline.org/make/gummy-bears","stations":6,"upstream":12,"downstream":0,"depth":3,"dek":"Gummy bears are poured into bear-shaped dents pressed in trays of cornstarch, and the starch is reused again and again.","answer":"Gummy bears are cooked from corn syrup, sugar, gelatin and water. The hot syrup is poured into tiny bear-shaped cavities pressed into trays of cornstarch, where it sets over a day or more as the starch pulls out extra moisture. The trays are tipped out, the bears are separated from the powder, and the starch is dried and reused.","aka":["gummi bears","gummibärchen","gummies"],"inputs":["sugar","corn-syrup","water","gelatin","corn-starch"],"uses":[],"grounds":["water","sugarcane","sugar-beet","corn","pigs","cattle-hide","limestone"],"upstreamSlugs":["sugar","corn-syrup","water","gelatin","corn-starch","sugarcane","sugar-beet","lime","corn","pigs","cattle-hide","limestone"],"downstreamSlugs":[],"steps":[{"name":"Cook the sweet syrup","process":"cook","text":"Sugar, corn syrup and water are boiled together until enough water has gone to give the right thickness. Corn syrup keeps the sugar from turning grainy.","inputs":["sugar","corn-syrup","water"]},{"name":"Stir in the gelling agent","process":"mix","text":"Hydrated gelatin, flavoring, color and a food acid such as citric acid or malic acid are blended into the hot syrup. The acid adds the sharp tang that balances the sugar. Vegan versions swap in pectin or starch for the gelatin.","inputs":["gelatin"]},{"name":"Stamp bears in starch","process":"mold","text":"Trays of cornstarch are smoothed flat and a plate of bear-shaped plugs is pressed into them, leaving rows of cavities. A depositor then fills each hollow with the warm liquid.","inputs":["corn-starch"]},{"name":"Rest while they set","process":"dry","text":"The gelatin cools into a springy gel while the surrounding starch soaks up water from the candy's surface. After this rest the bears are firm enough to handle.","inputs":[]},{"name":"Tip out and brush off","process":"separate","text":"Trays are dumped onto a screen and the bears are separated from the powder. The starch is dried and sent back to the line for the next round.","inputs":[]},{"name":"Bag the finished bears","process":"package","text":"Bears are dusted free of loose powder and weighed into bags. Gummies take up moisture in damp air and turn sticky, so the packaging has to be sealed well.","inputs":[]}],"facts":["The German name Gummibär means rubber bear.","Hans Riegel Sr., a candy maker from Bonn, started the company that became Haribo in the 1920s.","The first gelatin-based shaped candy was the Unclaimed Babies, sold by Fryers of Lancashire in 1864."],"where":[],"whereNote":null,"sources":[{"title":"Gummy candy","url":"https://en.wikipedia.org/wiki/Gummy_candy"},{"title":"Starch mogul","url":"https://en.wikipedia.org/wiki/Starch_mogul"},{"title":"Gelatin","url":"https://en.wikipedia.org/wiki/Gelatin"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"gypsum","name":"Gypsum","kind":"raw","category":"ground","title":"How gypsum is quarried","url":"https://assemblyline.org/make/gypsum","stations":3,"upstream":0,"downstream":10,"depth":0,"dek":"Gypsum is a mineral so soft you can scratch it with a fingernail, and it holds water inside its crystals.","answer":"Gypsum is a soft calcium sulfate mineral that forms thick beds when seawater or salty lakes dry up. It is dug from open quarries or underground mines, crushed and sorted. Heating it later drives off the water locked in its crystals, leaving the powder called plaster of Paris.","aka":["selenite","alabaster"],"inputs":[],"uses":["cement","drywall","plaster","chalk","tofu"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["cement","drywall","plaster","chalk","tofu","washing-machine","concrete","gold-ring","prosthetic-leg","skyscraper"],"steps":[{"name":"Quarry the evaporite bed","process":"mine","text":"Gypsum forms thick, extensive beds in sedimentary rock where water evaporated long ago. Quarries drill and blast the beds, or underground mines follow them.","inputs":[]},{"name":"Crush to chips","process":"crush","text":"Quarried rock is crushed and screened. Because gypsum is soft, it breaks down without much effort.","inputs":[]},{"name":"Sort for the plant","process":"separate","text":"Material is graded by purity and size. Most of it goes to a plant that heats it to make plaster, or sets it into wallboard, and some goes to farms as a soil amendment.","inputs":[]}],"facts":["Heating gypsum drives off water and leaves plaster of Paris, named for the quarries of the Montmartre district of Paris.","Gypsum crystals called selenite can grow up to 12 m long, among the largest crystals found in nature.","At White Sands National Park in New Mexico, 710 square kilometers of the dunes are made of gypsum sand."],"where":[],"whereNote":null,"sources":[{"title":"Gypsum","url":"https://en.wikipedia.org/wiki/Gypsum"},{"title":"Quarry","url":"https://en.wikipedia.org/wiki/Quarry"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hair-dye","name":"Hair dye","kind":"product","category":"body-health","title":"How hair dye is made","url":"https://assemblyline.org/make/hair-dye","stations":5,"upstream":44,"downstream":0,"depth":9,"dek":"Permanent hair color is a two-part kit, because the dye only forms inside the hair when the two halves meet.","answer":"Permanent hair dye is sold as two components. One is a colorant cream with ammonia, and the other is a developer, an oxidizing agent. Mixed on the head, the ammonia opens the hair's cuticle and the oxidizer lets the colorants form inside the cortex. Semi-permanent dyes skip both and only wedge under the cuticle.","aka":["hair color","hair colour","hair dye kit"],"inputs":["water","ammonia","hydrogen-peroxide","plastic-bottle","cardboard"],"uses":[],"grounds":["water","natural-gas","air","timber","rock-salt","limestone","crude-oil","corn","sulfur","sugarcane","sugar-beet","coal"],"upstreamSlugs":["water","ammonia","hydrogen-peroxide","plastic-bottle","cardboard","natural-gas","air","hydrogen","pet-plastic","wood-pulp","adhesive","p-xylene","ethylene","ethylene-glycol","timber","caustic-soda","lime","oxygen","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","naphtha","carbon-dioxide","rock-salt","limestone","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","corn","yeast","sulfur","benzene","molasses","toluene","sugarcane","sugar-beet","coal"],"downstreamSlugs":[],"steps":[{"name":"Prepare the colorants","process":"react","text":"Dye intermediates such as p-phenylenediamine are made by chemical routes in a plant. They are the colorless building blocks that develop color on the hair.","inputs":[]},{"name":"Blend the colorant cream","process":"mix","text":"A jacketed stainless steel vessel is charged with water and a thickening polymer and heated. Antioxidants and then the dye intermediates are dissolved one at a time, and the batch is cooled before the surfactant and ammonia go in.","inputs":["water","ammonia"]},{"name":"Make the developer","process":"mix","text":"The developer is a separate lotion of hydrogen peroxide, mixed in its own vessel. That vessel is first soaked in peroxide solution for 24 hours to passivate the steel, so the metal will not break down the oxidizer.","inputs":["water","hydrogen-peroxide"]},{"name":"Fill and pair the bottles","process":"fill","text":"The colorant tubes and developer bottles are filled separately, so nothing reacts until the customer mixes them.","inputs":["plastic-bottle"]},{"name":"Box the kit","process":"package","text":"Both parts are boxed together with instructions and gloves.","inputs":["cardboard"]}],"facts":["Assyrian herbals dating to 2177 BCE hold some of the oldest recorded recipes for hair dye.","Semi-permanent hair color survives only 4 to 8 shampoos, while demi-permanent lasts for about 20 to 28."],"where":[],"whereNote":null,"sources":[{"title":"Hair coloring","url":"https://en.wikipedia.org/wiki/Hair_coloring"},{"title":"p-Phenylenediamine","url":"https://en.wikipedia.org/wiki/P-Phenylenediamine"},{"title":"US patent 7,419,510: hair color compositions","url":"https://patents.google.com/patent/US7419510"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hairspray","name":"Hairspray","kind":"product","category":"body-health","title":"How hairspray is made","url":"https://assemblyline.org/make/hairspray","stations":7,"upstream":54,"downstream":0,"depth":7,"dek":"A spritz of hairspray leaves a thin plastic film on the hair once the solvent in each droplet has evaporated.","answer":"Most of a can of hairspray is solvent such as ethanol, carrying only a small volume of film-forming polymer. The liquid is blended and filled into open cans. On the line, a cap holding valve and dip tube sits loosely on top, a sealed bell pushes propellant in under it, and the same head then crimps the cap down for good.","aka":["hair spray","hair lacquer","spritz"],"inputs":["polyvinylpyrrolidone","plasticizer","ethanol","perfume","tinplate","propane"],"uses":[],"grounds":["natural-gas","water","air","corn","sugarcane","oranges","vanilla-pods","crude-oil","silica-sand","limestone","tin-ore","sugar-beet","rock-salt","trona","iron-ore","dolomite","manganese-ore","coal","quartz","timber","sulfur"],"upstreamSlugs":["polyvinylpyrrolidone","plasticizer","ethanol","perfume","tinplate","propane","natural-gas","formaldehyde","hydrogen","ammonia","water","hydrogen-peroxide","naphtha","air","propylene","corn","sugarcane","yeast","ethylene","oranges","vanilla-pods","glass-bottle","steel","tin","crude-oil","methanol","molasses","silica-sand","soda-ash","limestone","polyethylene","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","tin-ore","coke","sugar-beet","rock-salt","carbon-dioxide","trona","iron-ore","dolomite","silicon","manganese-ore","sulfuric-acid","coal","quartz","charcoal","timber","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Blend the polymers","process":"mix","text":"Copolymers of polyvinylpyrrolidone and polyvinyl acetate are mixed with plasticizers, surfactants and luster agents. Adjusting the polymer mix sets whether the hold is flexible, medium or maximum.","inputs":["polyvinylpyrrolidone","plasticizer"]},{"name":"Dissolve in solvent","process":"mix","text":"Solvents such as ethanol and isopropanol fill most of the can, while the polymer concentrate is only a small part of the volume. Fragrance goes in here too.","inputs":["ethanol","perfume"]},{"name":"Fill the open cans","process":"fill","text":"Cans of lacquered tinplate or aluminum travel to a filling unit, where liquid product drops through their open tops.","inputs":["tinplate"]},{"name":"Seat the cap loosely","process":"assemble","text":"At the next unit, a closure cap fitted with a valve and dip tube is placed on each can mouth without being fixed down, so gas can still get underneath.","inputs":[]},{"name":"Charge under the cap","process":"fill","text":"A bell chamber seals over the top of the can, and propellant entering it lifts the cap and flows in. Hydrocarbons such as propane, butane and isobutane are common, and dimethyl ether is often added since it also works as a solvent.","inputs":["propane"]},{"name":"Crimp the valve cap","process":"assemble","text":"The same head pushes the cap onto the mouth and crimps it permanently into a hermetic seal. This is the undercap method, one way aerosol lines load propellant.","inputs":[]},{"name":"Fit the button and pack","process":"package","text":"An actuator button goes on over the valve, with a nozzle that controls droplet size. Finished cans then leave for packing.","inputs":[]}],"facts":["Norwegian engineer Erik Rotheim won the first spray can patent in Oslo in 1927.","The modern spray can was put to use in 1941 by two U.S. entomology researchers, as the aerosol bomb for insects.","Chlorofluorocarbons were replaced after Rowland and Molina proposed in 1974 that they were depleting the ozone layer."],"where":[],"whereNote":null,"sources":[{"title":"US5181366A, Crimper-propellant fill head","url":"https://patents.google.com/patent/US5181366/en"},{"title":"Hair spray","url":"https://en.wikipedia.org/wiki/Hair_spray"},{"title":"Aerosol spray","url":"https://en.wikipedia.org/wiki/Aerosol_spray"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ham","name":"Ham","kind":"product","category":"food","title":"How ham is made","url":"https://assemblyline.org/make/ham","stations":6,"upstream":10,"downstream":0,"depth":3,"dek":"Most supermarket ham is pork pumped full of curing brine with needles so it takes days instead of months.","answer":"Ham is pork leg preserved by curing with salt. Dry-cured hams are packed in salt and hung to dry for months or even years. The faster factory route pumps a brine of salt, sugar and nitrite into the meat through needles, then tumbles, cooks or smokes it. Nitrite stops bacteria growth and keeps the meat pink.","aka":["cured ham","cooked ham","gammon"],"inputs":["pigs","table-salt","sugar","water"],"uses":[],"grounds":["pigs","water","rock-salt","seawater","sugarcane","sugar-beet","limestone"],"upstreamSlugs":["pigs","table-salt","sugar","water","rock-salt","seawater","sugarcane","sugar-beet","lime","limestone"],"downstreamSlugs":[],"steps":[{"name":"Trim the leg","process":"cut","text":"Pork legs are trimmed of surplus fat and skin and cleaned before curing.","inputs":["pigs"]},{"name":"Pump in the brine","process":"mix","text":"A curing solution of salt, nitrite, sugar and seasonings is pumped into the meat. This is faster than soaking, and it spreads salt evenly, usually in a few days.","inputs":["table-salt","sugar","water"]},{"name":"Soak in the cure","process":"mix","text":"The meat sits in brine or is tumbled so the cure reaches the middle. Brining by immersion takes around 3 to 14 days and increases the weight of the finished ham by about 4 percent.","inputs":[],"spec":"3 to 14 days in brine"},{"name":"Smoke or cook","process":"cook","text":"Wet-cured hams are usually cooked, either during processing or after aging. Smoking may be added for flavor. Italian prosciutto cotto is first brined, then cooked in a container and surface-pasteurized.","inputs":[]},{"name":"Chill and slice","process":"chill","text":"Cooked hams are cooled and then sliced or sold whole.","inputs":[]},{"name":"Or dry-cure the premium leg","process":"dry","text":"The slow alternative covers the leg in salt, presses out fluid and hangs it in a dark, temperature-regulated room. Enzymes break muscle into peptides and amino acids, which build flavor. Nitrites are added with the salt in most modern dry cures.","inputs":["table-salt"],"spec":"9 to 12 months for jamon serrano"}],"facts":["Nitrites in ham stop bacterial growth and react with myoglobin to give cured meat its red color.","Cato the Elder wrote about the salting of hams around 160 BC.","Iberian ham can take up to 2 years to reach the desired flavor."],"where":[],"whereNote":null,"sources":[{"title":"Ham","url":"https://en.wikipedia.org/wiki/Ham"},{"title":"Curing (food preservation)","url":"https://en.wikipedia.org/wiki/Curing_(food_preservation)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hammer","name":"Hammer","kind":"product","category":"hardware","title":"How hammers are made","url":"https://assemblyline.org/make/hammer","stations":8,"upstream":62,"downstream":0,"depth":10,"dek":"People used hammers 3.3 million years ago, long before any metal ones.","answer":"Toolmakers cut a steel bar to length and forge it hot, at 1200 to 1300 °C in one account, in shaped dies. A trimming tool removes flash, and broaching sets the size. Induction heating hardens only the striking face, and electrostatic coating protects the surface. A wooden handle is lathe turned, pushed through the eye and spread with a wedge.","aka":["claw hammer","carpenter's hammer"],"inputs":["steel","paint","lumber"],"uses":[],"grounds":["water","timber","iron-ore","limestone","air","dolomite","manganese-ore","natural-gas","titanium-ore","sulfur","coal","quartz","crude-oil","rock-salt","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["steel","paint","lumber","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","water","titanium-dioxide","pigment","acrylic","tin-can","timber","iron-ore","coke","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","titanium-ore","chlorine","carbon-black","sulfur","propylene","ammonia","methanol","tinplate","lacquer","ink","coal","quartz","charcoal","crude-oil","rock-salt","naphtha","tin","ethanol","vegetable-oil","phenolic-resin","hydrogen","tin-ore","corn","sugarcane","yeast","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","molasses","benzene","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Cut and heat the bar","process":"cut","text":"The bar is cut to an optimum length that wastes little steel, then heated to 1200 to 1300 °C.","inputs":["steel"],"spec":"1200-1300 °C"},{"name":"Forge in dies","process":"forge","text":"One die is fixed and the other drives down on a piston, often in stages with several shapes. Forging keeps the steel's grain unbroken, which helps a part that takes repeated blows.","inputs":[]},{"name":"Trim the flash","process":"cut","text":"A special trimming tool shears off the surplus metal around the forging while keeping the scrap as light as possible.","inputs":[]},{"name":"Broach to size","process":"machine","text":"Broaching takes the forging to its correct size.","inputs":[]},{"name":"Induction harden the face","process":"heat-treat","text":"Local heating and tempering at the impact surface give that spot a high hardness while the rest stays tougher, for a longer service life.","inputs":[]},{"name":"Coat the surface","process":"coat","text":"Electrostatic coating protects the steel from rust.","inputs":["paint"]},{"name":"Turn the handle","process":"machine","text":"Selected ash is cut to size, turned on a lathe, polished and protected. Steel-handled hammers instead use a rod pressed through a shaped hole.","inputs":["lumber"]},{"name":"Wedge in the handle","process":"assemble","text":"The wood is pushed up through the eye of the head and a wedge is driven in to spread it tight.","inputs":[]}],"facts":["Stone hammers date to around 3.3 million years ago, found at a site near Kenya's Lake Turkana.","A hammer's steel head is springy on purpose, since that elasticity helps pass the energy of the swing into the nail.","The claw hammer is the type most often found in North American households."],"where":[],"whereNote":null,"sources":[{"title":"Unior: Hammers, punches and chisels production process","url":"https://uniortools.com/ar/about-us/production-process/hammers-punches-and-chisels"},{"title":"Agriculture XPRT: How are hammers manufactured?","url":"https://www.agriculture-xprt.com/articles/how-are-hammers-manufactured-1076371"},{"title":"Hammer","url":"https://en.wikipedia.org/wiki/Hammer"},{"title":"Drop forging","url":"https://en.wikipedia.org/wiki/Drop_forging"},{"title":"Quenching","url":"https://en.wikipedia.org/wiki/Quenching"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hard-cider","name":"Hard cider","kind":"product","category":"drink","title":"How hard cider is made","url":"https://assemblyline.org/make/hard-cider","stations":7,"upstream":57,"downstream":0,"depth":9,"dek":"Cider apples are mashed to a pulp and pressed, and what runs out is fermented cool and slow to keep the aroma.","answer":"Hard cider is fermented apple juice. Apples are ground into pulp and pressed, and the juice is treated and fermented with yeast. A cool, slow fermentation preserves delicate aromas. The cider is racked off its yeast, matured, blended, and bottled, often with a little added sugar for sparkle.","aka":["cider","apple cider","cidre","sidra"],"inputs":["apples","yeast","sugar","glass-bottle","aluminum-can"],"uses":[],"grounds":["apples","water","sugarcane","sugar-beet","silica-sand","limestone","rock-salt","trona","crude-oil","coal","natural-gas","air","corn","bauxite","soybeans","rapeseed","clay","titanium-ore","iron-ore","sulfur"],"upstreamSlugs":["apples","yeast","sugar","glass-bottle","aluminum-can","water","molasses","sugarcane","sugar-beet","lime","silica-sand","soda-ash","limestone","polyethylene","aluminum","ink","epoxy","rock-salt","ammonia","carbon-dioxide","trona","ethylene","crude-oil","coal","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","phenol","propylene","acetone","chlorine","caustic-soda","natural-gas","air","corn","naphtha","bauxite","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","coke","oxygen","sulfuric-acid","iron-ore","sulfur","benzene","hydrogen","methanol","toluene"],"downstreamSlugs":[],"steps":[{"name":"Grind the apples","process":"crush","text":"Apples are scratted, which means ground to a coarse pulp, by a mill. Cider makers use bittersweet and sharp cider apples, culinary apples or a mix.","inputs":["apples"]},{"name":"Press out the juice","process":"press","text":"The pulp is pressed, traditionally in layers separated by cloth or straw, and today by a belt press. The leftover solids, called pomace, are fed to farm animals or composted.","inputs":[]},{"name":"Treat the juice","process":"mix","text":"Makers may blend juices, check acidity, and add a little sulfur dioxide to hold back spoilage microbes. Nitrogen nutrient may be added for the yeast.","inputs":[]},{"name":"Ferment cool and slow","process":"ferment","text":"Yeast turns the sugar into alcohol and carbon dioxide. Cider is fermented at a low temperature, which slows things and saves aroma that would blow off in a warmer tank.","inputs":["yeast"],"spec":"4–16 °C"},{"name":"Rack and rest","process":"dry","text":"The young cider is racked, or siphoned, into a clean vessel to leave the yeast behind. It then matures in the vat, sometimes for years.","inputs":[],"spec":"three months up to three years"},{"name":"Blend and sweeten","process":"mix","text":"Vats made from different apples are blended to suit the market. A fully fermented cider is dry, so a small dose of sugar sets the sweetness and the sparkle.","inputs":["sugar"]},{"name":"Bottle or keg","process":"fill","text":"Cider is filtered if a clear product is wanted, then bottled, canned or kegged. Higher-quality sparklers use the same second-fermentation method as champagne.","inputs":["glass-bottle","aluminum-can"]}],"facts":["Britain and Ireland together have the world's highest per capita cider consumption and the largest cider-producing companies.","Ice cider, from apples frozen before or after harvest, was developed in Quebec and runs at 9 to 13% alcohol by volume.","In the US and Canada, alcoholic cider is called hard cider to tell it apart from sweet cider, which is simply apple juice.","The first recorded reference to cider dates to Julius Caesar's attempt to invade Britain in 55 BCE."],"where":[],"whereNote":null,"sources":[{"title":"Cider","url":"https://en.wikipedia.org/wiki/Cider"},{"title":"Winemaking","url":"https://en.wikipedia.org/wiki/Winemaking"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hard-drive","name":"Hard drive","kind":"product","category":"electronics","title":"How hard drives are made","url":"https://assemblyline.org/make/hard-drive","stations":6,"upstream":76,"downstream":0,"depth":9,"dek":"A drive's read-write head flies tens of nanometers above a platter spinning at thousands of revolutions a minute.","answer":"A hard drive stores data on stacked platters made of aluminum or glass. They are polished until almost perfectly smooth, then sputtered in a vacuum with layers of cobalt-based magnetic alloy and topped with a carbon overcoat. In a cleanroom they are mounted on a spindle with read-write heads, sealed and tested.","aka":["HDD","hard disk","hard disk drive","fixed disk"],"inputs":["aluminum","glass","cobalt","chromium","platinum","steel","printed-circuit-board"],"uses":[],"grounds":["crude-oil","coal","silica-sand","limestone","cobalt-ore","chromite","air","water","platinum-ore","bauxite","rock-salt","trona","sulfur","natural-gas","iron-ore","dolomite","manganese-ore","copper-ore","corn","quartz","timber","tin-ore","lead-ore","silver-ore","zinc-ore","sugarcane","sugar-beet"],"upstreamSlugs":["aluminum","glass","cobalt","chromium","platinum","steel","printed-circuit-board","crude-oil","coal","petroleum-coke","alumina","silica-sand","soda-ash","limestone","cobalt-ore","sulfuric-acid","chromite","coke","air","water","platinum-ore","nitric-acid","hydrochloric-acid","ammonia","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","copper","fiberglass","epoxy","photoresist","solder","bauxite","caustic-soda","rock-salt","carbon-dioxide","trona","sulfur","chlorine","hydrogen","natural-gas","iron-ore","dolomite","silicon","propane","manganese-ore","copper-ore","phenol","propylene","acetone","phenolic-resin","tin","lead","silver","corn","yeast","quartz","charcoal","timber","benzene","naphtha","formaldehyde","tin-ore","lead-ore","zinc","silver-ore","zinc-ore","molasses","toluene","methanol","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Polish the platter blanks","process":"grind","text":"Disks of aluminum alloy or glass are polished, then mechanically textured with fine grooves that help the magnetic layers stick. Platters are among the smoothest surfaces manufactured anywhere, though not so smooth that the head cannot fly over them.","inputs":["aluminum","glass"]},{"name":"Sputter on magnetic layers","process":"deposit","text":"In a vacuum, magnetron sputtering coats both sides with underlayers and a recording film of a cobalt, chromium and platinum alloy. Thin layers of ruthenium separate the magnetic sub-layers.","inputs":["cobalt","chromium","platinum"],"spec":"magnetic film 10 to 20 nm"},{"name":"Add a carbon overcoat","process":"coat","text":"A diamond-like carbon overcoat is deposited next, and a lubricant goes on top, so the head can survive an occasional touch.","inputs":[]},{"name":"Build heads and arm","process":"assemble","text":"Each read-write head is made on a tiny scale and mounted on an arm moved by a voice coil actuator.","inputs":["steel"]},{"name":"Assemble in a cleanroom","process":"assemble","text":"Platters are stacked on the spindle motor, the heads are brought in and a controller board is attached. Platter work is done in cleanrooms often 100 times cleaner than a hospital operating room.","inputs":["printed-circuit-board"]},{"name":"Test the finished drive","process":"inspect","text":"The drive spins up and every region of every surface is tested.","inputs":[]}],"facts":["The protective carbon coat on a platter is diamond-like carbon about 2 nanometers thick.","IBM's 350 disk drive stored 3.75 megabytes on 52 disks and was about the size of two large refrigerators.","Platters spin at 5,400 or 7,200 rpm in most consumer drives."],"where":[],"whereNote":null,"sources":[{"title":"Hard disk drive","url":"https://en.wikipedia.org/wiki/Hard_disk_drive"},{"title":"Hard disk drive platter","url":"https://en.wikipedia.org/wiki/Hard_disk_drive_platter"},{"title":"How the humble hard drive is made, page 3","url":"https://www.techradar.com/news/computing-components/storage/how-the-humble-hard-drive-is-made-667183/3"},{"title":"Hard disk drive manufacturing process","url":"https://mydatarecoverylab.com/hard-disk-drive-manufacturing-process/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"suitcase","name":"Hard-shell suitcase","kind":"product","category":"textiles","title":"How hard-shell suitcases are made","url":"https://assemblyline.org/make/suitcase","stations":6,"upstream":81,"downstream":0,"depth":9,"dek":"A hard suitcase shell starts as a flat plastic sheet that is heated until soft and then sucked into a mold.","answer":"A hard-shell suitcase is made of two halves formed from polycarbonate, ABS or polypropylene sheet heated until floppy and pulled over a mold by vacuum. The halves are trimmed, lined and joined by a zipper or a metal frame. Wheels, a telescoping handle and locks are bolted on last.","aka":["hard-side luggage","polycarbonate suitcase","spinner luggage"],"inputs":["polycarbonate","abs-plastic","polypropylene","polyester","thread","adhesive","zipper","aluminum","steel","screw"],"uses":[],"grounds":["air","water","crude-oil","coal","rock-salt","natural-gas","iron-ore","sulfur","bauxite","limestone","dolomite","manganese-ore","zinc-ore","titanium-ore","copper-ore","lead-ore","tin-ore","quartz","timber","corn","sugarcane","sugar-beet"],"upstreamSlugs":["polycarbonate","abs-plastic","polypropylene","polyester","thread","adhesive","zipper","aluminum","steel","screw","phenol","propylene","acetone","caustic-soda","chlorine","naphtha","ammonia","air","benzene","ethylene","styrene","pigment","pet-plastic","water","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","nylon","brass","crude-oil","coal","petroleum-coke","alumina","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","steel-wire","zinc","rock-salt","sulfuric-acid","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","carbon-black","sulfur","p-xylene","ethylene-glycol","methanol","nitric-acid","copper","lead","tin","bauxite","coke","limestone","dolomite","silicon","propane","manganese-ore","zinc-ore","titanium-ore","carbon-dioxide","copper-ore","lead-ore","tin-ore","quartz","charcoal","timber","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Extrude the plastic sheet","process":"extrude","text":"Pellets of polycarbonate, ABS or polypropylene are melted in heated barrels and squeezed through a flat die, sometimes with several layers merged. Rollers then set the thickness and surface texture of the sheet.","inputs":["polycarbonate","abs-plastic","polypropylene"]},{"name":"Vacuum-form the halves","process":"mold","text":"A sheet is heated until it softens and placed over an aluminum mold. A vacuum pulls the plastic tight against every ridge and corner, and it cools on the mold. The corners stretch thinnest, so this is where weak shells crack.","inputs":[]},{"name":"Trim and drill","process":"machine","text":"Excess plastic around the edge is cut away. Polycarbonate gets too hard after forming to trim by hand without risking cracks, so factories use multi-axis CNC machines, which also cut the holes for handles and wheels.","inputs":[]},{"name":"Fit the lining","process":"sew","text":"Fabric is sewn into dividers and a lining, and then glued or riveted to the inside of each half. The lining protects the clothes from the hard plastic edge.","inputs":["polyester","thread","adhesive"]},{"name":"Add the frame or zipper","process":"assemble","text":"On a zipped case, a long coil zipper is riveted around both halves. On a frame case, aluminum strips are riveted around the rim, and clamps or locks hold the halves shut.","inputs":["zipper","aluminum"]},{"name":"Bolt on wheels and handle","process":"assemble","text":"Spinner wheels and a telescoping handle are screwed or riveted to reinforced plates. Sample cases go through a drop test, which is where a badly handled sheet shows up as a cracked corner.","inputs":["steel","screw"]}],"facts":["Wheels on suitcases were pitched to department stores by Bernard Sadow, who was granted a patent in 1972.","Rimowa began selling the first aluminum suitcase in 1950, with grooves modeled on the skin of a Junkers Ju 52 airplane."],"where":[],"whereNote":null,"sources":[{"title":"Suitcase","url":"https://en.wikipedia.org/wiki/Suitcase"},{"title":"PC luggage manufacturing process (Emay Bag)","url":"https://emaybag.com/post/pc-luggage-manufacturing-process/"},{"title":"US patent 5,376,322: thermoformed luggage shell","url":"https://patents.google.com/patent/US5376322"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hardwood-floor","name":"Hardwood flooring","kind":"product","category":"wood-paper","title":"How hardwood flooring is made","url":"https://assemblyline.org/make/hardwood-floor","stations":6,"upstream":15,"downstream":0,"depth":5,"dek":"Hardwood floorboards air-dry for months, then go in a kiln until they reach 6 to 8 percent moisture.","answer":"Hardwood logs are sawn into rough boards, air-dried for months and finished in a kiln so they will not warp. Planers bring them to thickness, and moulders cut tongue-and-groove edges. The boards are graded and sanded, then ship either unfinished for coating on site or with a factory finish already on.","aka":["solid wood flooring","wood floor","hardwood floors"],"inputs":["timber","polyurethane"],"uses":[],"grounds":["timber","water","crude-oil","air","rock-salt","natural-gas","sulfur"],"upstreamSlugs":["timber","polyurethane","propylene","nitric-acid","chlorine","water","naphtha","crude-oil","ammonia","air","rock-salt","sulfuric-acid","hydrogen","natural-gas","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Saw the logs into boards","process":"cut","text":"Logs are cut in one of three ways, plain-sawn, quarter-sawn or rift-sawn, which changes the grain pattern on the face of the floor.","inputs":["timber"]},{"name":"Air-dry and kiln-dry","process":"dry","text":"Boards are stacked in moving air for several months, then finished in a heated kiln. Controlled moisture keeps them from warping or shrinking after installation.","inputs":[],"spec":"6 to 8% moisture"},{"name":"Plane and grade","process":"inspect","text":"Planers bring boards to an even thickness. Graders sort them by color, grain and defects like knots, and rustic grades keep more of those marks.","inputs":[]},{"name":"Mill tongue and groove","process":"machine","text":"Cutters add a tongue on one side and a matching groove on the other, so neighbors lock together. Some makers also cut relief grooves in the back to reduce cupping.","inputs":[],"spec":"about 3/4 in solid boards"},{"name":"Sand and finish","process":"coat","text":"Boards are sanded smooth. Prefinished floors get stain and a protective polyurethane coat at the factory. Unfinished boards are left bare so the installer can sand and coat them after nailing.","inputs":["polyurethane"]},{"name":"Bundle for shipping","process":"package","text":"Each board gets a final check, and boards are bundled in cartons.","inputs":[]}],"facts":["Polyurethane floor finishes date to around 1942.","A floor refinish can take as little as 1/32 of an inch of wood.","Engineered wood flooring glues layers at right angles to one another, which makes it more stable than a solid plank."],"where":[],"whereNote":null,"sources":[{"title":"Hardwood flooring","url":"https://en.wikipedia.org/wiki/Hardwood_flooring"},{"title":"How Sheoga Hardwood Flooring Is Made","url":"https://sheogaflooring.com/about/our-process/"},{"title":"The Process of Making a Hardwood Floor Plank","url":"https://barnumfloors.com/wood-education/wood-education/the-process-of-making-a-hardwood-floor-plank/"},{"title":"Wood flooring","url":"https://en.wikipedia.org/wiki/Wood_flooring"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"harmonica","name":"Harmonica","kind":"product","category":"play","title":"How harmonicas are made","url":"https://assemblyline.org/make/harmonica","stations":8,"upstream":57,"downstream":0,"depth":7,"dek":"Hohner still tunes each reed against a matching one on a master plate fixed to a tuning table.","answer":"Thin brass reeds are the heart of a harmonica. A cutter profiles each brass strip, and a die punches out the reeds. Reeds are riveted over punched slots in a reed plate and tuned against a master plate. Two plates screw to a comb that forms the air chambers, and metal covers close it.","aka":["mouth organ","blues harp","harp"],"inputs":["brass","abs-plastic","lumber","steel","screw"],"uses":[],"grounds":["air","timber","copper-ore","water","zinc-ore","lead-ore","tin-ore","crude-oil","coal","natural-gas","iron-ore","sulfur","limestone","dolomite","manganese-ore","bauxite","titanium-ore","quartz","rock-salt"],"upstreamSlugs":["brass","abs-plastic","lumber","steel","screw","copper","zinc","lead","tin","aluminum","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","timber","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","steel-wire","copper-ore","water","sulfuric-acid","zinc-ore","lead-ore","coke","tin-ore","crude-oil","coal","petroleum-coke","alumina","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","carbon-black","sulfur","limestone","dolomite","silicon","propane","manganese-ore","bauxite","caustic-soda","titanium-ore","chlorine","quartz","charcoal","rock-salt"],"downstreamSlugs":[],"steps":[{"name":"Mill the brass strips","process":"machine","text":"Strips of rolled brass alloy get their reed profiles milled in. Hohner does this by hand at Trossingen for its classic diatonic models. A reed is a flat, elongated spring, and longer or heavier ones sound lower.","inputs":["brass"]},{"name":"Punch out the reeds","process":"stamp","text":"Die stamps cut the individual reeds from the milled strip.","inputs":[]},{"name":"Punch slots in the plates","process":"stamp","text":"Slots are punched into the reed plates to fit the reeds closely, because any gap leaks air.","inputs":["brass"]},{"name":"Rivet reeds over the slots","process":"assemble","text":"One end of each reed is riveted by hand over its slot so it lines up exactly. The other end stays free to swing through the slot.","inputs":[]},{"name":"Tune against a master plate","process":"grind","text":"Each reed's pitch is adjusted to match the same reed on a master plate fixed to the tuning table. Pitch changes with a reed's length, its weight near the free end, or its stiffness near the fixed end.","inputs":[]},{"name":"Form the comb","process":"mold","text":"The comb is the body that forms the air chambers. Many are ABS plastic. Hohner's Marine Band keeps a traditional comb of pearwood.","inputs":["abs-plastic","lumber"]},{"name":"Stamp the cover plates","process":"stamp","text":"Covers are stamped from metal to shield the reeds and direct the sound. Some covers are open, and some are enclosed.","inputs":["steel"]},{"name":"Screw it all together","process":"assemble","text":"Reed plates are screwed or bolted to the comb, one on top and one underneath, and the covers go on. Bolted plates can be swapped one at a time when a reed wears out.","inputs":["screw"]}],"facts":["Richter tuning, still used on nearly every standard harmonica, was created in 1826.","Wooden combs expand and shrink over time, which can crack them and leak air.","Reeds on the inner face of a plate answer to blowing, and those on the outer face to sucking."],"where":[],"whereNote":null,"sources":[{"title":"Hohner Pocket Guide: Harmonicas","url":"https://de.slideshare.net/MediaInstitute1/hohner-pocket-guideharmonicas2013engweb"},{"title":"Harmonica","url":"https://en.wikipedia.org/wiki/Harmonica"},{"title":"Free reed aerophone","url":"https://en.wikipedia.org/wiki/Free_reed_aerophone"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hazelnut-spread","name":"Hazelnut spread","kind":"product","category":"food","title":"How hazelnut spread is made","url":"https://assemblyline.org/make/hazelnut-spread","stations":7,"upstream":26,"downstream":0,"depth":7,"dek":"A big brand of hazelnut spread is mostly sugar and palm oil, with about 50 hazelnuts in each jar.","answer":"Hazelnuts are checked, cleaned and roasted, with air jets blowing out bad nuts. They are blended with cocoa powder, sugar, skimmed milk and vanilla flavor in big tanks. Palm oil and an emulsifier are added so the paste stays spreadable at room temperature and does not separate in the jar.","aka":["chocolate hazelnut spread","gianduja spread","nutella"],"inputs":["hazelnuts","cocoa-powder","sugar","powdered-milk","palm-oil","glass-jar"],"uses":[],"grounds":["hazelnuts","cocoa-beans","sugarcane","sugar-beet","water","raw-milk","oil-palm-fruit","limestone","silica-sand","rock-salt","trona","natural-gas","air","corn"],"upstreamSlugs":["hazelnuts","cocoa-powder","sugar","powdered-milk","palm-oil","glass-jar","cocoa-beans","sugarcane","sugar-beet","water","lime","raw-milk","oil-palm-fruit","glass","limestone","silica-sand","soda-ash","rock-salt","ammonia","carbon-dioxide","trona","natural-gas","air","corn","yeast","molasses"],"downstreamSlugs":[],"steps":[{"name":"Cut open and inspect","process":"inspect","text":"On arrival the nuts get a first quality check. A guillotine chops some to show the inside so inspectors can judge whether they are good enough.","inputs":["hazelnuts"]},{"name":"Clean and roast","process":"bake","text":"Hazelnuts are cleaned and roasted, which develops their flavor.","inputs":[]},{"name":"Blow out the bad nuts","process":"separate","text":"A computer-controlled blast of air knocks bad nuts out of the stream. This second check keeps every jar the same in color and taste.","inputs":[]},{"name":"Blend the base","process":"mix","text":"Nuts, cocoa powder, sugar, skimmed milk powder and vanilla flavor are combined in a large tank until they form a paste. Cocoa powder comes from beans that were roasted and pressed to squeeze out their butter.","inputs":["cocoa-powder","sugar","powdered-milk"]},{"name":"Add the fat","process":"mix","text":"Modified palm oil goes in to keep the paste soft but solid at room temperature, replacing the cocoa butter that was pressed out of the beans.","inputs":["palm-oil"]},{"name":"Bind and smooth it","process":"mix","text":"Whey powder acts as a binder, and lecithin helps oil and the other ingredients emulsify, so the paste turns spreadable and does not split.","inputs":[]},{"name":"Jar and seal","process":"fill","text":"The finished paste is filled into jars and sealed.","inputs":["glass-jar"]}],"facts":["Each 220-gram jar of Nutella uses about 50 hazelnuts.","Ferrero, the maker of Nutella, uses 25 percent of the global supply of hazelnuts.","The spread started in Piedmont, Italy, where hazelnuts were plentiful and cocoa was scarce after the war, so makers stretched cocoa with nut paste.","In 2012 a French proposal to raise the palm oil tax was nicknamed the Nutella tax."],"where":[],"whereNote":null,"sources":[{"title":"Nutella","url":"https://en.wikipedia.org/wiki/Nutella"},{"title":"Cocoa bean","url":"https://en.wikipedia.org/wiki/Cocoa_bean"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hazelnuts","name":"Hazelnuts","kind":"raw","category":"farm","title":"How hazelnuts are grown","url":"https://assemblyline.org/make/hazelnuts","stations":4,"upstream":0,"downstream":1,"depth":0,"dek":"Traditional hazelnut growers snap shoot tips on purpose to push the tree toward making more nuts.","answer":"Hazelnuts grow in husks on shrubby trees and drop free when ripe, seven to eight months after pollination. They are shelled and sold raw, roasted or ground into paste. Turkey grew 57.7 percent of the world's crop in 2023, and the nuts end up in chocolate spreads and pralines.","aka":["filberts","cobnuts","hazel nuts"],"inputs":[],"uses":["hazelnut-spread"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["hazelnut-spread"],"steps":[{"name":"Snap the shoot tips","process":"grow","text":"In the traditional method called brutting, growers snap, but do not break off, the tip of each new shoot at the end of the season. The tree then puts energy into flower buds, which means more nuts.","inputs":[]},{"name":"Wait for the fall","process":"grow","text":"A nut falls from its husk when ripe, about seven to eight months after pollination. It is a round to oval nut about 15 to 25 millimeters long.","inputs":[],"spec":"7 to 8 months after pollination"},{"name":"Sweep up and clean","process":"harvest","text":"Fallen nuts are swept or machine-lifted from the orchard floor. Husks and debris are removed before drying.","inputs":[]},{"name":"Crack the shell","process":"crush","text":"Shells are cracked to free the kernel, which makes up a third to half of the whole fruit depending on the cultivar. Kernels are sorted for roasting or sale.","inputs":[]}],"facts":["Turkey grew 57.7 percent of the world's hazelnuts in 2023.","Hazelnut shells found in a Scottish pit show people processing nuts on a large scale some 8,000 years ago.","Hazelnuts go into praline, chocolate bars and cocoa spreads such as Nutella."],"where":[{"place":"Turkey","share":"57.7% of world production"}],"whereNote":"2023 share of world hazelnut production, per Wikipedia.","sources":[{"title":"Hazelnut","url":"https://en.wikipedia.org/wiki/Hazelnut"},{"title":"Almond","url":"https://en.wikipedia.org/wiki/Almond"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"headphones","name":"Headphones","kind":"product","category":"electronics","title":"How headphones are made","url":"https://assemblyline.org/make/headphones","stations":6,"upstream":37,"downstream":0,"depth":7,"dek":"Inside each ear cup a coil of wire between magnets pushes a thin plastic sheet to make sound.","answer":"Most headphones are tiny loudspeakers. A permanent magnet of ferrite or neodymium holds a steady field. A voice coil of fine wire is attached to a thin diaphragm of polymer, cellulose or paper. When audio current flows through the coil, it moves the diaphragm. The drivers are fitted into plastic ear cups with cushions and a cable.","aka":["earphones","earbuds","cans","headset"],"inputs":["neodymium-magnet","ferrite","copper-wire","abs-plastic"],"uses":[],"grounds":["rare-earth-ore","iron-ore","manganese-ore","air","nickel-ore","zinc-ore","copper-ore","water","crude-oil","natural-gas","sulfur","coal","titanium-ore","rock-salt"],"upstreamSlugs":["neodymium-magnet","ferrite","copper-wire","abs-plastic","rare-earth-ore","nickel","zinc","iron-ore","zinc-oxide","manganese-ore","copper","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","nickel-ore","sulfuric-acid","zinc-ore","copper-ore","water","oxygen","crude-oil","hydrogen","natural-gas","toluene","titanium-dioxide","carbon-black","sulfur","coal","titanium-ore","chlorine","coke","rock-salt"],"downstreamSlugs":[],"steps":[{"name":"Shape the magnet","process":"press","text":"A permanent magnet, usually ferrite or neodymium, is formed to fit the driver frame. It sets up a static magnetic field.","inputs":["neodymium-magnet","ferrite"]},{"name":"Wind the voice coil","process":"assemble","text":"Very fine copper wire is wound into a light coil that is suspended inside the magnetic field.","inputs":["copper-wire"]},{"name":"Form the diaphragm","process":"mold","text":"A diaphragm is made from a lightweight, stiff material such as cellulose, polymer, carbon or paper. The coil is attached to it.","inputs":[]},{"name":"Assemble the driver","process":"assemble","text":"Magnet, coil and diaphragm are fixed inside a frame. A signal current through the coil changes the force against the magnet's field and moves the diaphragm back and forth.","inputs":[]},{"name":"Fit the ear cups and cable","process":"assemble","text":"Drivers go into molded plastic housings with cushions, a headband and a cable.","inputs":["abs-plastic"]},{"name":"Check each pair","process":"inspect","text":"Left and right drivers are measured to match in loudness and frequency response.","inputs":[]}],"facts":["Low-impedance headphones are 16 to 32 ohms, while high-impedance ones run 100 to 600.","Headphones for early radio were often 1,000 to 2,000 ohms, which suited crystal sets and triode receivers.","The 3.5 mm connector has been used at least since the Sony EFM-117J transistor radio of 1964."],"where":[],"whereNote":null,"sources":[{"title":"Headphones","url":"https://en.wikipedia.org/wiki/Headphones"},{"title":"Loudspeaker","url":"https://en.wikipedia.org/wiki/Loudspeaker"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hearing-aid","name":"Hearing aid","kind":"product","category":"body-health","title":"How hearing aids are made","url":"https://assemblyline.org/make/hearing-aid","stations":6,"upstream":75,"downstream":0,"depth":9,"dek":"A hearing aid is a microphone, a tiny computer and a speaker, usually run on a zinc-air button cell or a small rechargeable.","answer":"A hearing aid is a small computer that picks up sound, processes it and replays it louder. Its chip, microphones and receiver are mounted on a small circuit board. That board and a battery drawer fit inside a molded plastic case, or a custom shell made from a scan of the wearer's ear. The unit is then programmed and tested.","aka":["hearing device","behind-the-ear hearing aid"],"inputs":["printed-circuit-board","copper","microchip","solder","abs-plastic","silicone","zinc"],"uses":[],"grounds":["copper-ore","water","air","silica-sand","zinc-ore","limestone","sulfur","quartz","tin-ore","crude-oil","coal","gold-ore","lead-ore","silver-ore","natural-gas","iron-ore","timber","rock-salt","trona","bauxite","titanium-ore","corn","sugarcane","sugar-beet"],"upstreamSlugs":["printed-circuit-board","copper","microchip","solder","abs-plastic","silicone","zinc","fiberglass","epoxy","photoresist","copper-ore","water","oxygen","air","sulfuric-acid","silicon-wafer","tin","aluminum","gold","lead","silver","naphtha","propylene","ammonia","benzene","ethylene","styrene","pigment","silicon","methanol","hydrochloric-acid","silica-sand","zinc-ore","limestone","soda-ash","phenol","acetone","chlorine","caustic-soda","phenolic-resin","sulfur","polysilicon","quartz","argon","tin-ore","coke","crude-oil","coal","petroleum-coke","alumina","gold-ore","lime","lead-ore","silver-ore","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","carbon-black","charcoal","timber","rock-salt","carbon-dioxide","trona","formaldehyde","trichlorosilane","nitrogen","bauxite","titanium-ore","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Print the circuit board","process":"etch","text":"A thin flexible board is etched with copper tracks that link every component. It is only a few millimeters across in the smallest models.","inputs":["printed-circuit-board","copper"]},{"name":"Place the chip","process":"assemble","text":"A signal-processing chip, which splits sound into frequency bands and amplifies each one, is soldered onto the board along with capacitors and tiny resistors.","inputs":["microchip","solder"]},{"name":"Fit the microphones","process":"assemble","text":"Miniature microphones are attached to pick up sound, often in pairs so the device can favor sounds coming from the front. A receiver, the tiny loudspeaker, is wired in too.","inputs":[]},{"name":"Mold the case","process":"mold","text":"Plastic cases are injection molded. Custom in-the-ear shells are instead built from a scan of the wearer's ear canal so they fit exactly.","inputs":["abs-plastic","silicone"]},{"name":"Add the battery drawer","process":"assemble","text":"A battery door holds a button cell, usually a zinc-air type that draws oxygen from the air once its sealing tab is removed. Rechargeable models use a sealed cell instead.","inputs":["zinc"]},{"name":"Program and test","process":"inspect","text":"An audiologist's software tunes the amplification to the wearer's hearing test. The unit is then run through acoustic tests inside a sound-proof chamber.","inputs":[]}],"facts":["The transistor, invented in 1948, suited hearing aids well because it needed little power and was small, and hearing aids were early adopters.","Most modern hearing aids use one of five standard sizes of zinc-air button cell battery.","Small sound amplifiers sold to consumers cannot legally be called hearing aids, which are medical devices in most countries."],"where":[],"whereNote":null,"sources":[{"title":"Hearing aid","url":"https://en.wikipedia.org/wiki/Hearing_aid"},{"title":"Zinc-air battery","url":"https://en.wikipedia.org/wiki/Zinc%E2%80%93air_battery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"stent","name":"Heart stent","kind":"product","category":"body-health","title":"How heart stents are made","url":"https://assemblyline.org/make/stent","stations":6,"upstream":29,"downstream":0,"depth":6,"dek":"A heart stent starts as a thin metal tube, and a laser cuts it into a mesh that can collapse and then expand.","answer":"A coronary stent is a small mesh tube that props open a heart artery. Most current ones use a cobalt-chromium or platinum-chromium alloy. A laser cuts the mesh from thin-walled tubing, electropolishing smooths the struts, and a coating of drug is added. The stent is collapsed onto a balloon catheter, which later expands it in place, then packaged and sterilized.","aka":["coronary stent","arterial stent","drug-eluting stent"],"inputs":["cobalt","chromium"],"uses":[],"grounds":["cobalt-ore","chromite","limestone","air","water","sulfur","crude-oil","coal","rock-salt","trona","bauxite","natural-gas","corn","sugarcane","sugar-beet"],"upstreamSlugs":["cobalt","chromium","cobalt-ore","sulfuric-acid","aluminum","chromite","coke","soda-ash","limestone","air","water","sulfur","crude-oil","coal","petroleum-coke","alumina","rock-salt","ammonia","carbon-dioxide","lime","trona","bauxite","caustic-soda","natural-gas","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Draw the alloy tubing","process":"draw","text":"Stents start as thin-walled tubes of high-quality alloy. Current drug-eluting stents use cobalt-chromium or platinum-chromium, and stainless steel is the older choice.","inputs":["cobalt","chromium"]},{"name":"Laser-cut the mesh","process":"cut","text":"A fiber laser in a tube cutting system traces the pattern of struts around the tube, leaving a fine metal grid. That grid is what lets the stent be small on the way in and wide once in place.","inputs":[]},{"name":"Electropolish the struts","process":"etch","text":"The cut stent goes into an electrolytic acid solution, and electric current strips metal from its surface. This takes off the rough edges from cutting, since a rough surface in a blood vessel can promote clotting.","inputs":[]},{"name":"Coat with a drug layer","process":"coat","text":"A coating of limus-family drug such as everolimus or zotarolimus goes on the struts, often held in a polymer that controls its release into the artery wall. Some designs use no polymer.","inputs":[]},{"name":"Crimp onto the balloon","process":"assemble","text":"The stent is collapsed over the deflated balloon at the tip of a catheter. In this state it is small enough to pass through narrowed arteries.","inputs":[]},{"name":"Pack and sterilize","process":"package","text":"The stent and its catheter are sealed in a sterile package and sterilized before shipping.","inputs":[]}],"facts":["The word stent comes from Charles Stent, an English dentist who improved denture-making in the 19th century.","Coronary stenting began in 1986 with Jacques Puel and Ulrich Sigwart.","As of 2023, drug-eluting stents were used in more than 90 percent of procedures to open blocked heart arteries."],"where":[],"whereNote":null,"sources":[{"title":"Stent","url":"https://en.wikipedia.org/wiki/Stent"},{"title":"Drug-eluting stent","url":"https://en.wikipedia.org/wiki/Drug-eluting_stent"},{"title":"Coronary stent","url":"https://en.wikipedia.org/wiki/Coronary_stent"},{"title":"US patent 7,357,854: electropolishing cobalt-chromium devices","url":"https://patents.google.com/patent/US7357854"},{"title":"Cutting intricate microstructures (Laser Focus World)","url":"https://laserfocusworld.com/industrial-laser-solutions/article/14215833/cutting-intricate-microstructures"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hexane","name":"Hexane","kind":"material","category":"chemicals","title":"How hexane is made","url":"https://assemblyline.org/make/hexane","stations":5,"upstream":4,"downstream":162,"depth":2,"dek":"Cooking oil is pulled from soybeans with hexane, a solvent that boils at about 69 °C and evaporates away.","answer":"Refineries do not build hexane from scratch. They distill crude oil, then cut a narrow slice of naphtha boiling at about 65 to 70 °C. The result is a blend of isomers, about half straight-chain. Seed-oil crushers need it nearly free of benzene, so the aromatics come out by hydrogenation or solvent extraction before the liquid is sold.","aka":["n-hexane","hexanes"],"inputs":["crude-oil","hydrogen"],"uses":["vegetable-oil"],"grounds":["crude-oil","natural-gas","water"],"upstreamSlugs":["crude-oil","hydrogen","natural-gas","water"],"downstreamSlugs":["vegetable-oil","soap","shampoo","deodorant","sunscreen","mascara","detergent","ink","glycerin","cast-iron-pan","margarine","mayonnaise","peanut-butter","tortilla","donut","sandwich-cookie","potato-chips","french-fries","canned-tuna","chicken-nuggets","baby-formula","oat-milk","crackers","fish-sticks","biodiesel","wooden-spoon","pencil-eraser","modeling-clay","cake-mix","foundation-makeup","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","toothpaste","chewing-gum","snow-globe","cough-syrup","gelatin-capsule","diesel","vacuum-cleaner","electric-kettle","cotton-candy","pillow","paint","condensed-milk","coconut-milk","canned-meat","canned-soup","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","car","electric-car","nitrile-glove","washing-machine","paperclip","corn-flakes","popcorn","crayon","fireworks","candle","salsa","zip-bag","blender","dishwasher","cotton-swab","mouthwash","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","locomotive","refrigerator","microwave-oven","pencil","scissors","mirror","airplane","container-ship","shipping-container","bicycle","motorcycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","toy-car","coil-spring","hammer","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","padlock"],"steps":[{"name":"Heat the crude oil","process":"refine","text":"Heat separates crude oil into its distillates, light hydrocarbons from heavy ones. Naphtha comes off as a light cut with a wide boiling range, 50 to 140 °C in one patent.","inputs":["crude-oil"]},{"name":"Cut the narrow fraction","process":"separate","text":"Refiners fractionate again and keep only the slice boiling close to 69 °C. It still holds 3 to 15% aromatics, mainly benzene, which food use cannot accept.","inputs":[],"spec":"boils at 65 to 70 °C"},{"name":"Hydrogenate out the benzene","process":"react","inputs":["hydrogen"],"text":"One industry route runs the cut over a catalyst with hydrogen at raised temperature and pressure, which converts the benzene. Sulfur has to come out before this step. Other refiners use adsorption or catalytic distillation."},{"name":"Or extract with solvent","process":"separate","text":"Another route mixes the cut with a solvent such as sulfolane, which carries the aromatics away. One patent runs two extraction stages in a row, then washes the remaining hydrocarbon with water to remove carried-over solvent.","inputs":[]},{"name":"Check benzene and isomers","process":"inspect","text":"Food-grade limits have kept tightening, and one patent's process targets under 100 ppm of aromatics. The isomer mix varies with the oil it came from, with about 50 percent by weight usually straight-chain.","inputs":[]}],"facts":["Modern gasoline blends contain about 3 percent hexane.","Pure n-hexane has a research octane number of only 24.8, so it is poor engine fuel.","In 1981, hexane vapors illegally dumped by a soybean plant ignited in Louisville, Kentucky, and destroyed over 13 miles of sewer lines and streets."],"where":[],"whereNote":null,"sources":[{"title":"Hexane","url":"https://en.wikipedia.org/wiki/Hexane"},{"title":"Base oil","url":"https://en.wikipedia.org/wiki/Base_oil"},{"title":"US9611196B2, Process for obtaining food grade hexane","url":"https://patents.google.com/patent/US9611196"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"high-heels","name":"High heels","kind":"product","category":"textiles","title":"How high heels are made","url":"https://assemblyline.org/make/high-heels","stations":8,"upstream":79,"downstream":0,"depth":8,"dek":"A stiletto heel carries much of a person's weight on a very small tip, so a thin one has a metal rod down its center.","answer":"A high heel is built around a curved last and a hidden steel shank under the arch. Upper leather is cut, stitched and pulled over the last, then a sole is cemented on and passes through a heat tunnel to dry the glue. The last comes out, and a heel of wood or plastic around a core is nailed and glued in place.","aka":["stilettos","pumps","heeled shoes"],"inputs":["leather","thread","abs-plastic","steel","adhesive","rubber","screw"],"uses":[],"grounds":["cattle-hide","rock-salt","water","air","natural-latex","sulfur","limestone","chromite","crude-oil","natural-gas","iron-ore","dolomite","manganese-ore","zinc-ore","coal","trona","titanium-ore","quartz","timber","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["leather","thread","abs-plastic","steel","adhesive","rubber","screw","cattle-hide","rock-salt","water","lime","chromium","polyester","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","pig-iron","magnesium","steel-scrap","oxygen","manganese","argon","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","natural-latex","synthetic-rubber","carbon-black","sulfur","steel-wire","zinc","limestone","chromite","coke","soda-ash","aluminum","pet-plastic","crude-oil","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","dolomite","silicon","propane","manganese-ore","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","zinc-ore","coal","carbon-dioxide","trona","petroleum-coke","alumina","p-xylene","ethylene-glycol","titanium-ore","quartz","charcoal","timber","corn","yeast","bauxite","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Choose the last","process":"inspect","text":"Before cutting can begin, the last is selected for the style. Lasts for high heels come in many shapes and sizes, and the height of the heel is built into the curve.","inputs":[]},{"name":"Cut the upper pieces","process":"cut","text":"Leather or fabric is cut by machine into the vamp, quarters and lining. Pieces are stacked in kits, and their edges are skived so they fold neatly.","inputs":["leather"]},{"name":"Stitch the upper","process":"sew","text":"Most heels need only a few stitching operations, so a few workers join the pieces and attach the lining. The upper has not yet taken the curve of the shoe, so it lies almost flat.","inputs":["thread"]},{"name":"Mold the heel","process":"mold","text":"A heel is shaped from plastic in a mold or turned from wood. A thin heel has a metal rod down the center to keep it from snapping, and its tip is capped with a hard plastic or rubber lift.","inputs":["abs-plastic","steel"]},{"name":"Pull it over the last","process":"press","text":"The upper is pulled tight over the high, curved last and glued to the insole, which carries a steel shank under the arch. Pulling it tight sets the final shape of the shoe.","inputs":["steel","adhesive"]},{"name":"Cement the sole","process":"press","text":"A leather or rubber sole is cemented to the bottom and pressed under load. The shoe travels through a heat tunnel on the way, which dries the glue.","inputs":["rubber","adhesive"]},{"name":"Nail on the heel","process":"assemble","text":"The last is pulled out, and the heel is driven on with nails or screws from inside the shoe. An insole is glued over the fixings.","inputs":["screw"]},{"name":"Finish and inspect","process":"inspect","text":"The shoe is cleaned and polished, and pairs are checked against each other. Stress-testing the heel catches weak bonds.","inputs":[]}],"facts":["The tall, skinny stiletto heel was invented in 1950.","One small fashion shoe line completes about 250 pairs a day, against 1,000 or 1,500 on a large sports shoe line.","Venice tried to limit the height of platform shoes to three inches, but the rule was widely ignored."],"where":[],"whereNote":null,"sources":[{"title":"High-heeled shoe","url":"https://en.wikipedia.org/wiki/High-heeled_shoe"},{"title":"Tour a footwear factory making women's high heel shoes (Shoemakers Academy)","url":"https://shoemakersacademy.com/tour-footwear-factory-making-womens-high-heel-shoes/"},{"title":"Shoe making process (Shoemakers Academy)","url":"https://shoemakersacademy.com/shoe-making-process/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"highlighter","name":"Highlighter","kind":"product","category":"plastics","title":"How highlighters are made","url":"https://assemblyline.org/make/highlighter","stations":6,"upstream":45,"downstream":0,"depth":8,"dek":"Most yellow highlighters glow because of a single dye called pyranine.","answer":"A highlighter is a felt-tip marker filled with transparent fluorescent ink instead of opaque ink. The barrel and cap are molded plastic, the nib is porous fiber or sintered plastic, and a fiber reservoir inside soaks up a measured dose of ink. Ink then wicks from reservoir to nib.","aka":["fluorescent pen","highlighter pen","text marker"],"inputs":["ink","plastic","polyester"],"uses":[],"grounds":["water","natural-gas","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","coal","sugar-beet","limestone"],"upstreamSlugs":["ink","plastic","polyester","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","naphtha","natural-gas","ethylene","propylene","pet-plastic","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","hydrogen","p-xylene","ethylene-glycol","benzene","methanol","rock-salt","coal","molasses","carbon-dioxide","toluene","sugar-beet","limestone"],"downstreamSlugs":[],"steps":[{"name":"Dissolve the fluorescent dye","process":"mix","text":"A fluorescent dye is dissolved in a liquid so the ink is see-through instead of opaque. Pyranine gives the common yellow, and rhodamines make other colors.","inputs":["ink"]},{"name":"Mold the body","process":"mold","text":"Barrel, cap and plugs are molded from plastic resin in the same way as for other markers.","inputs":["plastic"]},{"name":"Form the chisel nib","process":"mold","text":"Nibs are either polyester fiber held by a bonding resin, or polyethylene powder sintered into a porous shape. The chisel shape lets one stroke cover the full line of text.","inputs":["polyester"]},{"name":"Slide in the reservoir","process":"assemble","text":"A cylinder of packed fibers in a thin seal slides into the barrel. Crushing it or setting it off-center hurts how it holds and releases ink.","inputs":["polyester"]},{"name":"Dose the ink","process":"fill","text":"An automated head dispenses a measured amount of ink into the reservoir, which soaks it up like a sponge.","inputs":[]},{"name":"Press nib, cap and test","process":"assemble","text":"Operators press the nib in until it touches the saturated reservoir, and the cap and end plug are seated. A bad cap seal dries a pen out in weeks, so pens are checked for flow and leaks.","inputs":[]}],"facts":["Dr. Frank Honn invented the first highlighter in 1963, and Carter's Ink Company produced it under the name Hi-Liter.","Yellow is the preferred highlighter color for marking pages you will photocopy, because it does not cast a shadow on the copy."],"where":[],"whereNote":null,"sources":[{"title":"Highlighter","url":"https://en.wikipedia.org/wiki/Highlighter"},{"title":"Marker Pen Machine: The Complete Manufacturing Guide","url":"https://masstechx.com/blog/marker-pen-machine-blog/"},{"title":"Highlighter Nibs and Reservoirs","url":"https://www.porex.com/consumer-goods/writing-instruments/highlighter-nibs-and-reservoirs/"},{"title":"Marker","url":"https://encyclopedia.com/manufacturing/news-wires-white-papers-and-books/marker"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hiking-boots","name":"Hiking boots","kind":"product","category":"textiles","title":"How hiking boots are made","url":"https://assemblyline.org/make/hiking-boots","stations":6,"upstream":58,"downstream":0,"depth":8,"dek":"Hiking boots owe their grip to a tread called tank track that was designed after six climbers died in a storm.","answer":"A hiking boot takes more than 100 production steps and up to 200 parts. Leather upper pieces are punched out, skived, stitched and reinforced, then stretched over a last. A molded rubber sole with deep lugs is cemented on in a press. The cemented construction makes the boot sturdy and lets it be resoled later.","aka":["trekking boots","walking boots","mountaineering boots"],"inputs":["leather","nylon","thread","adhesive","rubber","carbon-black"],"uses":[],"grounds":["cattle-hide","rock-salt","water","natural-latex","sulfur","crude-oil","air","limestone","chromite","natural-gas","coal","trona","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["leather","nylon","thread","adhesive","rubber","carbon-black","cattle-hide","rock-salt","water","lime","chromium","benzene","nitric-acid","ammonia","polyester","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","natural-latex","synthetic-rubber","sulfur","crude-oil","air","limestone","chromite","coke","soda-ash","aluminum","naphtha","hydrogen","toluene","natural-gas","pet-plastic","ethylene","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","styrene","coal","carbon-dioxide","trona","petroleum-coke","alumina","p-xylene","ethylene-glycol","corn","yeast","bauxite","oxygen","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Punch out the upper parts","process":"cut","text":"A unique punch knife for each part and size is pressed into the leather, and its spikes mark where the lace holes go. Leather with minor visual defects goes to parts hidden inside the boot.","inputs":["leather","nylon"]},{"name":"Stitch and reinforce the upper","process":"sew","text":"Reinforcing pieces with a layer of glue are sealed onto the upper sections in an ironing press. Panels are sewn together, a heel cap and padding are glued in, and lace hooks are riveted on.","inputs":["thread","adhesive"]},{"name":"Stretch it over the last","process":"mold","text":"The upper is pulled tight over a foot-shaped last and its bottom edge is lasted down onto an insole. Heat helps the leather set into the shape of the last.","inputs":["adhesive"]},{"name":"Mold the outsole","process":"mold","text":"Rubber is pressed in a hot steel mold to form the lugged sole. Heat and pressure cure it so it stays tough and springy, and the deep lugs bite into mud and loose rock.","inputs":["rubber","carbon-black"]},{"name":"Cement on the sole","process":"press","text":"Glue is applied to the upper and to the sole unit, and a press bonds the two. Hanwag runs about 40 processes in its sole assembly hall.","inputs":["adhesive"]},{"name":"Lace and inspect","process":"inspect","text":"Insoles are dropped in, laces threaded, and each boot is checked for stitching flaws and gaps between the sole and the upper.","inputs":["nylon"]}],"facts":["The first major improvement in mountaineering boots followed a deadly climbing accident in 1935, when six of Vitale Bramani's companions died in a snowstorm.","Bramani's 1937 vulcanized rubber sole, called Carrarmato, Italian for tank tread, replaced hobnails."],"where":[],"whereNote":null,"sources":[{"title":"Hiking boot","url":"https://en.wikipedia.org/wiki/Hiking_boot"},{"title":"Vulcanization","url":"https://en.wikipedia.org/wiki/Vulcanization"},{"title":"How a boot is made (Hanwag)","url":"https://production.hanwag.com/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hip-implant","name":"Hip implant","kind":"product","category":"body-health","title":"How hip implants are made","url":"https://assemblyline.org/make/hip-implant","stations":9,"upstream":47,"downstream":0,"depth":6,"dek":"A forged hip stem is polished in acid, partly so hidden cracks stay open and show up under fluorescent dye.","answer":"A hip stem is usually forged from cobalt-chromium or titanium close to its final shape. Scale is blasted off, then the surface is machined, polished and checked for cracks with fluorescent dye. Bone-contact areas may get a plasma-sprayed coating. The cup liner is cut from consolidated polyethylene, and parts are laser marked, sealed in double pouches in a cleanroom and sterilized.","aka":["hip replacement","artificial hip","hip prosthesis"],"inputs":["cobalt","chromium","titanium","ceramic","polyethylene"],"uses":[],"grounds":["cobalt-ore","chromite","limestone","air","water","titanium-ore","clay","kaolin","feldspar","quartz","sulfur","crude-oil","coal","rock-salt","trona","dolomite","natural-gas","bauxite","corn","timber","sugarcane","sugar-beet"],"upstreamSlugs":["cobalt","chromium","titanium","ceramic","polyethylene","cobalt-ore","sulfuric-acid","aluminum","chromite","coke","soda-ash","limestone","air","water","titanium-ore","chlorine","magnesium","argon","clay","kaolin","feldspar","quartz","ethylene","sulfur","crude-oil","coal","petroleum-coke","alumina","rock-salt","ammonia","carbon-dioxide","lime","trona","dolomite","silicon","naphtha","natural-gas","bauxite","caustic-soda","corn","yeast","charcoal","timber","hydrogen","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Forge near final shape","process":"forge","inputs":["cobalt","chromium","titanium"],"text":"A cobalt-chromium or titanium body is pressed in forging dies to a shape only slightly bigger than the finished part. Near-net forging means little metal has to be cut away later, though stems can also be cast or milled."},{"name":"Blast off the scale","process":"grind","inputs":[],"text":"Forging heat leaves a scale on the metal. One patent blasts it off with fine beads hard enough to clean the surface, yet gently enough not to smear small cracks shut."},{"name":"Trim and machine","process":"machine","inputs":[],"text":"CNC mills, lathes and grinders remove the flash and cut the critical features. One French plant quotes tolerances down to ±0.01mm for metal and polymer parts."},{"name":"Polish in acid","process":"etch","inputs":[],"text":"In the patent's method, the part sits in an acid bath with current running through it, which strips a thin skin and leaves a bright finish. It is then cleaned ultrasonically."},{"name":"Hunt cracks with dye","process":"inspect","inputs":[],"text":"A fluorescent penetrant seeps into any open crack or lap and glows under inspection. Measuring machines also check dimensions against the drawing."},{"name":"Spray the coating","process":"coat","inputs":["titanium"],"text":"Plasma torches spray titanium or hydroxyapatite in air or vacuum onto grit-blasted surfaces where the implant will meet bone."},{"name":"Finish the ball","process":"grind","inputs":["ceramic"],"text":"Femoral heads of metal or ceramic are ground to tight tolerances and delivered fully finished, ready for sterilizing."},{"name":"Cut the cup liner","process":"machine","inputs":["polyethylene"],"text":"Ultra-high-molecular-weight polyethylene powder is ram extruded or compression molded into solid stock, then machined into a liner. Some makers use radiation to cross-link it so it wears more slowly."},{"name":"Mark, pouch and sterilize","process":"package","inputs":[],"text":"Parts are laser marked, passivated and given a last cleaning. In a Class 8 cleanroom they go into double vacuum pouches or sealed blisters, ready for gamma or ethylene oxide sterilizing."}],"facts":["Shot peening can smear a forging crack shut, hiding it from the dye that is supposed to find it.","One implant plant in Chaumont, France, turns out over 12 million implants a year.","Charnley's polyethylene cup, introduced in 1962, and his use of bone cement shaped modern hip replacement."],"where":[],"whereNote":null,"sources":[{"title":"US6025536: Process of manufacturing a cobalt-chromium orthopaedic implant","url":"https://patents.google.com/patent/US6025536"},{"title":"Hip Solutions | Tecomet","url":"https://tecomet.com/medical-markets/specialty/hip"},{"title":"Chaumont, France: Advanced Manufacturing for Orthopedic Implants | Viant","url":"https://viantmedical.com/?p=6255"},{"title":"US6017975: Process for medical implant of cross-linked ultrahigh molecular weight polyethylene","url":"https://patents.google.com/patent/US6017975"},{"title":"Hip replacement","url":"https://en.wikipedia.org/wiki/Hip_replacement"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hockey-puck","name":"Hockey puck","kind":"product","category":"play","title":"How hockey pucks are made","url":"https://assemblyline.org/make/hockey-puck","stations":8,"upstream":6,"downstream":0,"depth":2,"dek":"Some hockey pucks are baked in a mold for about 18 minutes at 300 °F, then left alone for a full day to harden.","answer":"A hockey puck is a disc of vulcanized rubber mixed from natural rubber and additives. The mix is milled, pushed into long logs 3 inches across, and cut into 1-inch slices. Each slice goes into a mold and is pressed under heat. The puck hardens for a day, then gets trimmed and cleaned.","aka":["puck","ice hockey puck"],"inputs":["natural-latex","carbon-black","sulfur"],"uses":[],"grounds":["natural-latex","sulfur","crude-oil","air","water"],"upstreamSlugs":["natural-latex","carbon-black","sulfur","crude-oil","air","water"],"downstreamSlugs":[],"steps":[{"name":"Blend the rubber mix","process":"mix","text":"Natural rubber is combined with antioxidants, bonding materials and other chemicals. The recipe balances hardness against resilience.","inputs":["natural-latex","carbon-black","sulfur"]},{"name":"Roll it on metal mills","process":"knead","text":"The mixture is turned between metal rollers, where workers add extra natural rubber and make sure it is even.","inputs":[]},{"name":"Test a sample","process":"inspect","text":"A machine checks that a sample of the rubber will harden at the right temperature.","inputs":[]},{"name":"Extrude long logs","process":"extrude","text":"An extruder pushes the soft rubber out in logs 3 inches (7.6 cm) in diameter.","inputs":[]},{"name":"Slice into pucks","process":"cut","text":"The logs are cut into 1-inch (2.5 cm) pieces while the rubber is still soft.","inputs":[]},{"name":"Mold under heat","process":"mold","text":"Workers set the slices into molds the exact size of a finished puck, with up to 200 cavities per palette. Some makers compress the molds cold, and others at 300 °F for 18 minutes.","inputs":[],"spec":"300 °F for 18 minutes"},{"name":"Let them harden","process":"dry","text":"Pucks come out hard and rest for 24 hours.","inputs":[]},{"name":"Trim off the flash","process":"cut","text":"A trimmer machine cleans extra rubber from each puck. The molding leaves a diamond cross-hatch on the edge for grip.","inputs":[]}],"facts":["A standard ice hockey puck is 1 inch thick, 3 inches wide and weighs between 5.5 and 6 ounces.","Early rubber pucks were made by slicing a rubber ball and trimming the disc square.","Tracking pucks hold circuitry and a six-hour battery inside the rubber, and flash infrared light 60 times a second."],"where":[],"whereNote":null,"sources":[{"title":"Hockey puck","url":"https://en.wikipedia.org/wiki/Hockey_puck"},{"title":"Ice hockey equipment","url":"https://en.wikipedia.org/wiki/Ice_hockey_equipment"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"honey","name":"Honey","kind":"product","category":"food","title":"How honey is made","url":"https://assemblyline.org/make/honey","stations":7,"upstream":1,"downstream":2,"depth":1,"dek":"Bees pass nectar mouth to mouth for 20 minutes, then fan it from 70 percent water to under 18.","answer":"Foragers collect nectar and hand it to hive bees, who bubble it between their mouthparts and drip it into wax cells. Wings fan the nectar until most of its water evaporates and it caps off as honey. Beekeepers pull the frames, slice the caps off, spin the honey out in a centrifuge, strain it and jar it.","aka":["raw honey","comb honey","bee honey"],"inputs":["honeycomb"],"uses":["granola-bar","mead"],"grounds":["honeycomb"],"upstreamSlugs":["honeycomb"],"downstreamSlugs":["granola-bar","mead"],"steps":[{"name":"Gather the nectar","process":"harvest","text":"A forager drinks nectar into its honey stomach, which holds about 40 mg. Filling it can take visits to more than a thousand flowers. The nectar is 70 to 80 percent water.","inputs":[]},{"name":"Pass it mouth to mouth","process":"mix","text":"Back at the hive, workers take the nectar and pass it along in a relay, repeatedly forming bubbles between their mandibles. It can take as long as 20 minutes of this regurgitating, digesting and evaporating before the product is fit for storage.","inputs":[]},{"name":"Fan off the water","process":"dry","text":"The bees spread the drops in open wax cells, then beat their wings. The hive runs at around 35 °C, and the evaporation continues until the water content is between 15.5 and 18 percent.","inputs":[],"spec":"15.5 to 18% water"},{"name":"Cap the cells with wax","process":"coat","text":"When the honey is ripe the bees seal each cell with a lid of beeswax. Sealed honey keeps indefinitely so long as its water content stays below about 18 percent.","inputs":[]},{"name":"Smoke the bees and pull frames","process":"harvest","text":"A beekeeper calms the bees with a smoker, which triggers a feeding instinct and masks the pheromones they use to communicate. Frames of capped comb are lifted out of the hive.","inputs":[]},{"name":"Spin the honey out","process":"separate","text":"Wax caps are sliced off, and the frames are spun in a drum-shaped extractor so centrifugal force flings the honey out without destroying the comb. The empty frames go back to the bees.","inputs":["honeycomb"]},{"name":"Strain and jar it","process":"fill","text":"The honey is strained to take out wax bits and may be warmed gently during bottling to delay crystallizing. Heating to 40 to 49 °C can slow granulation, though overheating destroys enzymes.","inputs":[]}],"facts":["Cave paintings in Spain show people foraging for honey at least 8,000 years ago.","A forager's honey stomach holds about 40 mg of nectar, and filling it can take visits to more than a thousand flowers.","Honey should not be given to babies, because of the risk of infant botulism."],"where":[{"place":"China","share":"24% of world production"}],"whereNote":"2023, when world production was 1.9 million tonnes.","sources":[{"title":"Honey","url":"https://en.wikipedia.org/wiki/Honey"},{"title":"Sugar","url":"https://en.wikipedia.org/wiki/Sugar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"honeycomb","name":"Honeycomb","kind":"raw","category":"farm","title":"How honeycomb is made and harvested","url":"https://assemblyline.org/make/honeycomb","stations":4,"upstream":0,"downstream":11,"depth":0,"dek":"Bees eat roughly 8.4 pounds of honey to build a single pound of wax comb.","answer":"Honey bees build honeycomb from beeswax secreted by their own bodies, forming hexagonal cells that hold brood, honey and pollen. Beekeepers keep the bees in hives with removable frames. At harvest they take frames of capped comb, and either cut the comb out or uncap it and spin the honey out in a centrifuge.","aka":["beeswax comb","comb honey","beekeeping","bee hive frames","honey comb"],"inputs":[],"uses":["lipstick","mascara","honey","beeswax"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["lipstick","mascara","honey","beeswax","granola-bar","mead","gold-ring","jelly-beans","candy-coated-chocolate","licorice","bronze-statue"],"steps":[{"name":"Build the wax cells","process":"grow","text":"Bees make hexagonal prism cells from wax, tilted upward by 9 to 14 degrees so the honey stays put. Hexagons divide a surface into equal cells with the least perimeter, so the least wax.","inputs":[]},{"name":"Fill and cap with honey","process":"grow","text":"Foragers bring nectar that is 70 to 80% water. Hive bees pass it around and fan it until it reaches roughly 18% water, then seal it into the cell. Making a full load of nectar can take visits to more than one thousand flowers.","inputs":[]},{"name":"Pull the frames","process":"harvest","text":"Beekeepers remove frames of capped comb from the hive, driving the bees off with smoke. Worn-out comb is melted down for wax, and good comb can be returned to the hive.","inputs":[]},{"name":"Uncap and spin","process":"separate","text":"The wax cappings are cut off and the frame is spun in a centrifugal honey extractor, which flings out the honey and leaves the comb structure largely intact for reuse.","inputs":[]}],"facts":["Bees consume about 8.4 lb (3.8 kg) of honey to secrete 1 lb (450 g) of wax.","The angle between adjacent surfaces at the closed end of each cell is 120 degrees, which minimizes surface area for a given volume.","Before movable-comb hives, collecting honey often meant destroying the whole colony."],"where":[],"whereNote":null,"sources":[{"title":"Honeycomb","url":"https://en.wikipedia.org/wiki/Honeycomb"},{"title":"Beekeeping","url":"https://en.wikipedia.org/wiki/Beekeeping"},{"title":"Honey","url":"https://en.wikipedia.org/wiki/Honey"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hoodie","name":"Hoodie","kind":"product","category":"textiles","title":"How hoodies are made","url":"https://assemblyline.org/make/hoodie","stations":6,"upstream":22,"downstream":0,"depth":8,"dek":"The hoodie began as a work garment for people stacking boxes in freezing New York warehouses.","answer":"A hoodie is cut from a heavy knitted fabric, usually cotton or a cotton and polyester blend, with soft loops on the inside. Machines cut the front, back, sleeve and hood panels in stacks, and sewing crews join them. The hood gets a drawcord, the front gets a kangaroo pocket, and ribbed cuffs and a waistband close the openings.","aka":["hooded sweatshirt","pullover hoodie","zip hoodie"],"inputs":["cotton-yarn","polyester","thread"],"uses":[],"grounds":["raw-cotton","water","natural-gas","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["cotton-yarn","polyester","thread","raw-cotton","pet-plastic","water","p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","oxygen","carbon-dioxide","crude-oil","hydrogen","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Blend the yarn","process":"spin","text":"Cotton fibers, often mixed with polyester, are drawn out and twisted into yarn. Adding polyester makes the finished garment dry faster and hold its shape after washing.","inputs":["cotton-yarn","polyester"]},{"name":"Knit the loop-back fabric","process":"weave","text":"Knitting machines loop the yarn into a stretchy fabric that is smooth on the outside. The inside is left with soft loops of yarn that trap warm air. The fabric comes off the machine as a wide tube or flat roll.","inputs":[]},{"name":"Dye and brush the cloth","process":"dye","text":"The whole roll is dyed in a bath, then dried. Many hoodies are also brushed on the inside, which raises the loops into a fuzzy lining.","inputs":[]},{"name":"Cut stacks of panels","process":"cut","text":"Cloth is spread in many layers on a table so every ply lies the same way. An automatic CNC cutter, or a manual knife on small orders, goes through the stack and produces the body, sleeves, pockets, hood panels and rib pieces in one pass.","inputs":[]},{"name":"Sew the body and hood","process":"sew","text":"The panels move along a sewing line where each operator does one job, such as setting the sleeves, joining the hood panels or building the pouch pocket. Overlock, flatlock and coverstitch machines make the seams.","inputs":["thread"]},{"name":"Add ribbing and drawcord","process":"assemble","text":"Stretchy ribbed bands are sewn on at the cuffs and waist so the hoodie hugs the wrist and hip. A drawcord is threaded through a tunnel around the hood opening, and a final check looks for loose threads and uneven seams.","inputs":["cotton-yarn"]}],"facts":["The first hooded sweatshirts were made by Champion in the 1930s, in Rochester, for laborers in freezing upstate New York warehouses.","A hoodie is usually sewn on a line, where one operator may do nothing but sleeves and another nothing but pockets."],"where":[],"whereNote":null,"sources":[{"title":"Hoodie","url":"https://en.wikipedia.org/wiki/Hoodie"},{"title":"How hoodies are made (Thygesen Apparel)","url":"https://thygesenapparel.com/blog/how-hoodies-are-made"},{"title":"The sweatshirt factory (Sanvt)","url":"https://sanvt.com/pages/factories-the-sweatshirt-factory"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"velcro","name":"Hook-and-loop fastener","kind":"product","category":"textiles","title":"How hook-and-loop fasteners are made","url":"https://assemblyline.org/make/velcro","stations":5,"upstream":12,"downstream":0,"depth":6,"dek":"Hook-and-loop tape is woven with tiny loops, and one of the two strips then has its loops cut into hooks.","answer":"Nylon yarn is woven into a flat tape with a field of tiny raised loops. Stiff monofilament goes into the hook tape, and softer fibers into the loop tape. Heat sets the loops so they hold their shape. On the hook half, a blade snips each loop on one side, leaving a hooked stem.","aka":["Velcro","hook and loop tape","touch fastener"],"inputs":["nylon"],"uses":[],"grounds":["air","water","natural-gas","crude-oil","coal"],"upstreamSlugs":["nylon","benzene","nitric-acid","ammonia","naphtha","hydrogen","toluene","air","water","natural-gas","crude-oil","coal"],"downstreamSlugs":[],"steps":[{"name":"Spin the nylon yarn","process":"spin","text":"Nylon is melted and forced through fine holes into thread. Hook tape uses a stiff single-strand monofilament. Early cotton versions frayed and wore out quickly, which is why the inventor moved to synthetic fiber.","inputs":["nylon"]},{"name":"Weave a looped tape","process":"weave","text":"A loom weaves a flat base strip and raises rows of tiny loops from its face. Mechanizing this took years, since each loop has to form in the same way.","inputs":[]},{"name":"Heat-set the loops","process":"heat-treat","text":"Heat fixes the shape of the woven monofilament, often under infrared light. The nylon remembers the shape, so the loops stand up and stay open.","inputs":[]},{"name":"Snip loops into hooks","process":"cut","text":"On the hook side, reciprocating blades shear each loop across the width of the tape. Each loop becomes a single stiff hook that can catch the soft loops of the other half. On the other tape the loops stay uncut.","inputs":[]},{"name":"Slit and reel the tape","process":"package","text":"Wide woven tape is slit into narrow strips, and wound on reels for sewing or stick-on backing.","inputs":[]}],"facts":["George de Mestral conceived hook-and-loop fasteners in 1941 after studying burdock burrs that stuck to his dog's fur.","It took ten years to build a mechanized process that worked.","When the patent expired in 1978, cheap imitations from Taiwan, China and South Korea flooded in."],"where":[],"whereNote":null,"sources":[{"title":"Hook-and-loop fastener","url":"https://en.wikipedia.org/wiki/Hook-and-loop_fastener"},{"title":"What is VELCRO Brand Hook & Loop Fastener Material Made Of?","url":"https://dev.hookandloop.com/blog/what-is-hook-loop-made-of"},{"title":"Woven hook and loop fastening (US patent 6546603)","url":"https://patents.google.com/patent/US6546603"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hops","name":"Hops","kind":"raw","category":"farm","title":"How hops are grown and harvested","url":"https://assemblyline.org/make/hops","stations":3,"upstream":0,"downstream":3,"depth":0,"dek":"Hop bines climb overhead trellises, and only the female plants are grown, so the cones never form seeds.","answer":"Hops are the cones of a climbing vine. Only female plants are grown, so the cones are never pollinated, and the bines are trained up strings to an overhead trellis. At the end of summer the bines are cut down, the cones are stripped off by machine, and the cones are dried in a kiln.","aka":["hop cones","hop farming","hop harvest","hop vine"],"inputs":[],"uses":["beer","light-beer","non-alcoholic-beer"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["beer","light-beer","non-alcoholic-beer"],"steps":[{"name":"Train bines up strings","process":"grow","text":"Plants stand in rows about 2 to 2.5 meters apart. Each spring the roots send up new bines, which are started up strings to an overhead trellis. Only female plants are grown, and they are propagated vegetatively, so no seeds form.","inputs":[]},{"name":"Cut the bines down","process":"harvest","text":"Hops are harvested at the end of summer. The bines are cut, and a mechanical separator, patented by Emil Clemens Horst in 1909, strips the cones off. Before that the cones were picked by hand.","inputs":[]},{"name":"Kiln-dry the cones","process":"dry","text":"Drying in an oast house cuts the moisture content. Modern kilns use big fans to force clean, heated air through the beds of hops. The dried hops are then compressed into bales.","inputs":[]}],"facts":["Much of the world's hop production sits near the 48th parallel north.","Hop cones contain lupulin, a yellowish waxy substance that gives beer its flavor and aroma.","Whole families once traveled to Kent to pick the annual harvest and lived in huts called hoppers' huts."],"where":[],"whereNote":null,"sources":[{"title":"Hops","url":"https://en.wikipedia.org/wiki/Hops"},{"title":"Humulus lupulus","url":"https://en.wikipedia.org/wiki/Humulus_lupulus"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hot-dog","name":"Hot dog","kind":"product","category":"food","title":"How hot dogs are made","url":"https://assemblyline.org/make/hot-dog","stations":7,"upstream":9,"downstream":0,"depth":3,"dek":"A hot dog starts as a pink batter of ground meat, cure, spice and ice, blended in rapidly spinning blades.","answer":"Trimmings of pork, beef or poultry are ground and blended with salt, cure, spices and ice in a bowl cutter. The smooth batter is pumped into casings, cooked and smoked in ovens, and chilled. For skinless hot dogs a cellulose casing is peeled off before the franks are packed.","aka":["frankfurter","wiener","frank"],"inputs":["pigs","cattle","chickens","table-salt","water","sausage-casing"],"uses":[],"grounds":["pigs","cattle","chickens","water","rock-salt","seawater","cattle-hide"],"upstreamSlugs":["pigs","cattle","chickens","table-salt","water","sausage-casing","rock-salt","seawater","cattle-hide"],"downstreamSlugs":[],"steps":[{"name":"Grind the meat trimmings","process":"crush","text":"Pork and beef, or cheaper chicken and turkey, are ground. Raw material includes lean meat, fat and trimmings that cutting leaves behind.","inputs":["pigs","cattle","chickens"]},{"name":"Mix and emulsify","process":"mix","text":"In a big vat, rapidly moving blades grind and mix meat, salt, spices, binders and cure in the same operation. Ice keeps it cold while the proteins dissolve and bind the fat into a smooth batter. The cure is typically sodium nitrite with sodium erythorbate.","inputs":["table-salt","water"]},{"name":"Stuff into casings","process":"fill","text":"The batter is forced through tubes into casings. Natural casings come from sheep intestines. Most hot dogs sold in the United States use a long cellulose tube instead.","inputs":["sausage-casing"]},{"name":"Cook and smoke","process":"cook","text":"Links hang on racks in ovens where hot air and smoke cook them through and set the pink color. Hot dogs are fully cooked before they leave the plant.","inputs":[]},{"name":"Shower with cold water","process":"chill","text":"Cooked franks pass through a cold-water shower so the casing does not wrinkle and they stop cooking.","inputs":[]},{"name":"Peel the cellulose casing","process":"cut","text":"For skinless hot dogs a machine slits the cellulose casing and pulls it off. Erwin Freund invented this process in Chicago in 1925.","inputs":[]},{"name":"Pack in vacuum","process":"package","text":"Franks are counted into plastic packs and vacuum sealed for the cold chain.","inputs":[]}],"facts":["The first skinless hot dog casings were sold as Nojax, short for no jackets.","Natural casing hot dogs have a firmer snap than skinless ones."],"where":[],"whereNote":null,"sources":[{"title":"Hot dog","url":"https://en.wikipedia.org/wiki/Hot_dog"},{"title":"Curing (food preservation)","url":"https://en.wikipedia.org/wiki/Curing_%28food_preservation%29"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hot-sauce","name":"Hot sauce","kind":"product","category":"food","title":"How hot sauce is made","url":"https://assemblyline.org/make/hot-sauce","stations":7,"upstream":30,"downstream":0,"depth":6,"dek":"The most famous Louisiana hot sauce ferments in used whiskey barrels for up to three years before it is bottled.","answer":"Hot sauce starts with ripe chili peppers, ground into a mash the same day they are picked and salted. The mash is aged in barrels for up to three years in one classic recipe. Skins and seeds are strained out, vinegar is stirred in for a month, and the thin red liquid is bottled.","aka":["pepper sauce","chili sauce","tabasco-style sauce"],"inputs":["chili-pepper","table-salt","vinegar","glass-bottle"],"uses":[],"grounds":["chili-pepper","rock-salt","seawater","grapes","water","silica-sand","limestone","corn","sugarcane","barley","trona","natural-gas","sugar-beet","air","crude-oil"],"upstreamSlugs":["chili-pepper","table-salt","vinegar","glass-bottle","rock-salt","seawater","grapes","ethanol","malted-barley","yeast","water","silica-sand","soda-ash","limestone","polyethylene","corn","sugarcane","ethylene","barley","molasses","ammonia","carbon-dioxide","lime","trona","naphtha","natural-gas","sugar-beet","air","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Pick peppers at peak red","process":"harvest","text":"Pickers compare each pepper to a small red stick and take only the ones that match its color. Growers now farm the peppers in Central America, South America and Africa, with seed stock from Louisiana.","inputs":[]},{"name":"Grind to a mash","process":"crush","text":"Peppers are ground into a mash on the day they are harvested, before they start to spoil.","inputs":["chili-pepper"]},{"name":"Salt and barrel the mash","process":"mix","text":"The mash goes into white oak barrels with salt. The barrels have been used for whiskey, and are decharred, torched and cleaned first so the mash does not pick up whiskey flavor.","inputs":["table-salt"]},{"name":"Age it in the warehouse","process":"ferment","text":"Barrels sit in warehouses while the mash slowly ferments and mellows. Many other sauces are simpler, with peppers pureed and cooked together with vinegar and salt.","inputs":[],"spec":"up to 3 years"},{"name":"Strain off skins and seeds","process":"separate","text":"The aged mash is pushed through a strainer that holds back skins and seeds. What passes through is a deep red pepper liquid.","inputs":[]},{"name":"Stir in vinegar","process":"mix","text":"Distilled vinegar goes into the liquid, which is stirred now and then for about a month. Vinegar is a natural preservative as well as a flavoring.","inputs":["vinegar"],"spec":"about 1 month"},{"name":"Bottle the sauce","process":"fill","text":"The sauce is filled into small glass bottles. One Louisiana factory fills as many as 720,000 two-ounce bottles in a day.","inputs":["glass-bottle"]}],"facts":["One of the first bottled hot sauces sold in the United States appeared in Massachusetts in 1807.","The Tabasco brand dates from 1868 and is sold in more than 195 countries and territories.","Some hot sauces get extra heat from pure capsaicin extract, since even the hottest ghost peppers only go so far."],"where":[],"whereNote":null,"sources":[{"title":"Hot sauce","url":"https://en.wikipedia.org/wiki/Hot_sauce"},{"title":"Tabasco sauce","url":"https://en.wikipedia.org/wiki/Tabasco_sauce"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hydrochloric-acid","name":"Hydrochloric acid","kind":"material","category":"chemicals","title":"How hydrochloric acid is made","url":"https://assemblyline.org/make/hydrochloric-acid","stations":5,"upstream":8,"downstream":56,"depth":3,"dek":"Most hydrochloric acid is a by-product of making other chemicals, caught and dissolved in water.","answer":"Hydrochloric acid is hydrogen chloride gas dissolved in water. Since 2000 most has been made by absorbing hydrogen chloride that other chemical plants give off, and a smaller share is made directly from hydrogen and chlorine. The solution is stored in lined tanks and shipped, and steel mills use much of it to clean rust.","aka":["muriatic acid","spirits of salt","HCl"],"inputs":["chlorine","hydrogen","water"],"uses":["deodorant","silicone","polysilicon","platinum","trichlorosilane","germanium","iridium"],"grounds":["water","rock-salt","natural-gas","sulfur","air"],"upstreamSlugs":["chlorine","hydrogen","water","rock-salt","sulfuric-acid","natural-gas","sulfur","air"],"downstreamSlugs":["deodorant","silicone","polysilicon","platinum","trichlorosilane","germanium","iridium","shampoo","syringe","condom","hearing-aid","solar-panel","contact-lens","airbag","cork-stopper","pressure-cooker","blender","foundation-makeup","eyeshadow","prosthetic-leg","double-glazed-window","remote-control","electric-toothbrush","silicon-wafer","hard-drive","optical-fiber","satellite","car","electric-car","champagne","aluminum-window-frame","microchip","memory-chip","camera-sensor","solar-cell","inkjet-printer","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","rocket","smartwatch","wireless-earbuds","phone-charger","usb-cable","digital-camera","game-console","wifi-router","e-reader","graphics-card"],"steps":[{"name":"Collect the gas","process":"react","text":"Making plastics and other organic chemicals releases hydrogen chloride gas. Plants capture it rather than vent it.","inputs":["chlorine"]},{"name":"Burn hydrogen in chlorine","process":"react","text":"Direct synthesis burns hydrogen in chlorine to make hydrogen chloride. This is often tied to the chloralkali process, which produces chlorine and hydrogen together.","inputs":["hydrogen","chlorine"]},{"name":"Recover it from spent pickle liquor","process":"react","text":"Steel mills regenerate spent acid by pyrohydrolysis, which drives hydrogen chloride back out of the used liquid. The iron oxide that remains is sold.","inputs":[]},{"name":"Dissolve it in water","process":"mix","text":"The gas is absorbed in water to produce the acid. Dissolving it is highly heat-releasing, so absorbers are cooled.","inputs":["water"]},{"name":"Store and ship in lined tanks","process":"fill","text":"The strong acid is stored and moved in tanks lined with resistant materials. A common technical grade for steel cleaning is about 18 percent.","inputs":[]}],"facts":["Only about 3 million of the roughly 20 million tonnes of hydrochloric acid made each year come from direct synthesis.","Steel mills dip steel in it to remove rust and scale before rolling or galvanizing."],"where":[],"whereNote":null,"sources":[{"title":"Hydrochloric acid","url":"https://en.wikipedia.org/wiki/Hydrochloric_acid"},{"title":"Hydrofluoric acid","url":"https://en.wikipedia.org/wiki/Hydrofluoric_acid"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hydrogen","name":"Hydrogen","kind":"material","category":"chemicals","title":"How hydrogen is made","url":"https://assemblyline.org/make/hydrogen","stations":6,"upstream":2,"downstream":458,"depth":1,"dek":"Most hydrogen is stripped out of natural gas with steam, and it ends up in fertilizer and refineries.","answer":"Most hydrogen comes from natural gas. Methane and steam react over a nickel catalyst in a furnace-heated tube bundle, giving hydrogen and carbon monoxide. A second reaction with steam turns the monoxide into more hydrogen and carbon dioxide, and the hydrogen is purified. Electrolyzers can split water instead.","aka":["H2","steam methane reforming","green hydrogen","gray hydrogen"],"inputs":["natural-gas","water"],"uses":["acetaminophen","vitamin-c","naphtha","gasoline","diesel","jet-fuel","paraffin-wax","polysilicon","led","tungsten","window-glass","margarine","rocket","benzene","hydrochloric-acid","hexane","germanium","motor-oil","hydrogen-peroxide","iridium","polyvinylpyrrolidone"],"grounds":["natural-gas","water"],"upstreamSlugs":["natural-gas","water"],"downstreamSlugs":["acetaminophen","vitamin-c","naphtha","gasoline","diesel","jet-fuel","paraffin-wax","polysilicon","led","tungsten","window-glass","margarine","rocket","benzene","hydrochloric-acid","hexane","germanium","motor-oil","hydrogen-peroxide","iridium","polyvinylpyrrolidone","flour","ethylene","propylene","polystyrene","abs-plastic","synthetic-rubber","p-xylene","plastic","toluene","plasticizer","car","car-engine","motorcycle","locomotive","airplane","jet-engine","deodorant","sunscreen","lipstick","mascara","adhesive","pencil","chewing-gum","turbine-blade","crayon","candle","cork-stopper","printer-toner","golf-club","eyeshadow","dental-floss","mdf","match","silicon-wafer","led-bulb","lcd-screen","television","computer-mouse","pinball-machine","e-reader","remote-control","light-bulb","tungsten-carbide","drill-bit","mirror","skyscraper","windshield","double-glazed-window","nylon","phenol","spandex","styrene","acetone","silicone","platinum","trichlorosilane","vegetable-oil","optical-fiber","hair-dye","wood-pulp","silk","towel","hairspray","bread","instant-noodles","tortilla","croissant","donut","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","fish-sticks","modeling-clay","licorice","cake-mix","shampoo","polyethylene","pvc","pet-plastic","ethanol","polyvinyl-alcohol","ethylene-glycol","polypropylene","acrylic","polycarbonate","epoxy","polyurethane","carbon-fiber","pvb","acrylic-acid","surfboard","bike-helmet","ballpoint-pen","polystyrene-foam","foam-cup","smoke-detector","compact-disc","inkjet-printer","hearing-aid","thermometer","lego-brick","3d-printer-filament","laptop","computer-keyboard","headphones","rubiks-cube","snowboard","action-figure","harmonica","globe","suitcase","high-heels","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","graphics-card","electric-toothbrush","toothbrush","syringe","rubber","nitrile-glove","tire","golf-ball","basketball","pencil-eraser","flip-flops","rubber-boots","kevlar","duct-tape","aa-battery","solar-panel","refrigerator","washing-machine","vacuum-cleaner","nonstick-pan","marker-pen","highlighter","fountain-pen","toaster","roller-skates","tennis-racket","bowling-ball","dice","yo-yo","board-game","jigsaw-puzzle","trading-cards","snow-globe","toy-car","tampon","wet-wipes","asthma-inhaler","prosthetic-leg","wheelchair","light-switch","power-outlet","seat-belt","backpack","eyeglass-frame","microphone","umbrella","nail-polish","yoga-mat","vinyl-floor","cellulose-acetate","adhesive-bandage","credit-card","ev-battery","nail","insulation","popcorn","skateboard","guitar","piano","violin","drum-kit","tennis-ball","baseball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","clear-tape","staple","sofa","ski","ice-skates","fishing-rod","volleyball","cricket-bat","dartboard","chess-set","kite","ukulele","cello","drumstick","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","brake-pad","sailboat","dress-shirt","suit","raincoat","handbag","wallet","hiking-boots","smartwatch","loudspeaker","camera-lens","plywood","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","sneaker","leather-shoe","baseball-cap","carpet","mattress","diaper","champagne","treadmill","microchip","memory-chip","camera-sensor","solar-cell","digital-camera","saw-blade","electric-car","aluminum-window-frame","drone","airbag","velcro","dishwasher","office-chair","fashion-doll","underwear","leggings","swimsuit","down-jacket","flag","socks","zipper","rope","aspirin","billiard-ball","phenolic-resin","shoelace","condom","contact-lens","pressure-cooker","blender","foundation-makeup","hard-drive","soap","detergent","ink","glycerin","cast-iron-pan","mayonnaise","peanut-butter","potato-chips","french-fries","canned-tuna","baby-formula","oat-milk","biodiesel","wooden-spoon","paper","facial-tissue","rayon","silk-tie","winter-gloves","toothpaste","hip-implant","plastic-bag","lithium-ion-cell","glass-bottle","frozen-peas","bubble-wrap","plastic-wrap","zip-bag","paper-cup","thermos","frisbee","power-cable","car-battery","garden-hose","football","inflatable-pool-toy","chain-link-fence","pvc-pipe","vinyl-record","polyester","plastic-bottle","bottled-water","perfume","vaccine","vanilla-extract","vinegar","gin","lacquer","super-glue","port-wine","insect-repellent","air-freshener","mouthwash","banknote","electric-kettle","plastic-straw","n95-mask","paint","sunglasses","eyeglass-lens","printed-circuit-board","wind-turbine","electric-motor","rebar","aluminum-can","pacemaker","soccer-ball","hardwood-floor","water-heater","satellite","bicycle","superabsorbent-polymer","shipping-container","dumbbell","ladder","wheelbarrow","fire-extinguisher","canoe","ceiling-fan","fireworks","soda","energy-drink","paperclip","corn-flakes","cotton-candy","salsa","canned-meat","pillow","cough-syrup","smartphone","solid-state-drive","jeans","photoresist","tin-can","wallpaper","candy-coated-chocolate","floor-tile","newspaper","t-shirt","gelatin-capsule","drywall","egg-carton","penicillin","insulin","ketchup","cola","sparkling-water","beer","wine","whiskey","vodka","rum","tequila","sake","hard-cider","hot-sauce","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","prosecco","non-alcoholic-beer","candy-cane","hoodie","curtain","button","thread","teddy-bear","bleach","dish-soap","ice-cream","white-chocolate","caramel","mustard","pickles","electric-guitar","trumpet","chopsticks","saxophone","felt-hat","baseball-bat","microwave-oven","scissors","container-ship","water-bottle","coil-spring","hammer","gas-cylinder","neon-sign","suspension-bridge-cable","subway-train","leather-belt","elevator","air-conditioner","concrete","light-beer","indium-tin-oxide","condensed-milk","coconut-milk","canned-soup","blanket","sweater","padlock","oled-screen","toffee"],"steps":[{"name":"Remove sulfur from the gas","process":"refine","text":"Natural gas first passes through a bed that captures sulfur compounds. Sulfur would poison the nickel catalyst downstream.","inputs":["natural-gas"]},{"name":"React gas with steam","process":"react","text":"The gas and steam flow down long narrow tubes packed with nickel catalyst, inside a furnace. The reaction soaks up heat, so burners fire constantly to keep the tubes hot.","inputs":["water"]},{"name":"Shift the carbon monoxide","process":"react","text":"A second reactor mixes the gas with more steam. The carbon monoxide is converted into extra hydrogen and carbon dioxide.","inputs":[]},{"name":"Scrub out the carbon dioxide","process":"wash","text":"A liquid solvent absorbs the carbon dioxide, which is either vented or captured for storage and sale. The gas that remains is mostly hydrogen.","inputs":[]},{"name":"Purify the hydrogen","process":"separate","text":"Pressure-swing beds soak up the last traces of other gases and leave nearly pure hydrogen. It is compressed and piped to refineries and ammonia plants.","inputs":[]},{"name":"Split water with electricity","process":"electrolyze","text":"Electrolyzers pass electric current through water and collect hydrogen at one electrode. When the power comes from wind or solar, the product is called green hydrogen.","inputs":["water"]}],"facts":["Hydrogen made from natural gas and released without capturing the carbon dioxide is called gray hydrogen, and most hydrogen today is gray.","Steam reforming of natural gas makes almost half of the world's hydrogen, and it is the cheapest method in capital cost."],"where":[],"whereNote":null,"sources":[{"title":"Hydrogen production","url":"https://en.wikipedia.org/wiki/Hydrogen_production"},{"title":"Steam reforming","url":"https://en.wikipedia.org/wiki/Steam_reforming"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"hydrogen-peroxide","name":"Hydrogen peroxide","kind":"material","category":"chemicals","title":"How hydrogen peroxide is made","url":"https://assemblyline.org/make/hydrogen-peroxide","stations":6,"upstream":4,"downstream":93,"depth":2,"dek":"The net recipe is hydrogen plus oxygen, yet the two never meet. A recycled carrier molecule passes the atoms across.","answer":"Nearly all of it comes from one looping process. An anthraquinone dissolved in solvent picks up hydrogen over a catalyst, then gives that hydrogen to oxygen when compressed air bubbles through. The peroxide is washed out of the liquid and the carrier goes back around to collect more hydrogen, cycle after cycle.","aka":["peroxide","H2O2","oxygen bleach"],"inputs":["hydrogen","air","water"],"uses":["hair-dye","polyvinylpyrrolidone","wood-pulp","silk","towel"],"grounds":["air","water","natural-gas"],"upstreamSlugs":["hydrogen","air","water","natural-gas"],"downstreamSlugs":["hair-dye","polyvinylpyrrolidone","wood-pulp","silk","towel","hairspray","nail-polish","kitchen-sponge","sanitary-pad","cellulose-acetate","paper","cardboard","toilet-paper","facial-tissue","rayon","diaper","silk-tie","winter-gloves","sunglasses","dice","shoelace","eyeglass-frame","soap","adhesive-bandage","aa-battery","vacuum-cleaner","drywall","popcorn","crayon","fireworks","plastic-straw","paper-straw","paper-cup","paper-bag","pizza-box","egg-carton","wallpaper","laminate-floor","board-game","jigsaw-puzzle","tampon","cotton-swab","loudspeaker","vinyl-record","compact-disc","inkjet-printer","newspaper","book","envelope","sticky-notes","playing-cards","toothbrush","duct-tape","plastic-wrap","clear-tape","trading-cards","cake-mix","soda","energy-drink","cardboard-box","match","leather-shoe","candy-cane","toothpaste","deodorant","detergent","plastic-bag","nitrile-glove","washing-machine","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","candle","salsa","canned-meat","fish-sticks","zip-bag","blender","dishwasher","pillow","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","syringe"],"steps":[{"name":"Load the carrier solution","process":"mix","text":"An anthraquinone, an expensive organic molecule, is dissolved in a blend of solvents. This working solution stays in the plant permanently. The economics depend on recycling it along with the catalyst.","inputs":[]},{"name":"Hydrogenate over palladium","process":"react","text":"Hydrogen gas meets the solution over a palladium catalyst. The carrier takes on two loosely held hydrogen atoms and becomes an anthrahydroquinone.","inputs":["hydrogen"]},{"name":"Bubble compressed air through","process":"react","text":"Air is pushed through the loaded solution. Oxygen pulls the loose hydrogen atoms off the carrier, forming the peroxide and turning the carrier back into its starting form.","inputs":["air"]},{"name":"Wash the product out","process":"separate","text":"The new peroxide is extracted from the organic solution. The carrier goes back to the hydrogen step, and the loop starts over.","inputs":["water"]},{"name":"Concentrate under vacuum","process":"refine","text":"Water is removed under reduced pressure at low temperature, since the product falls apart in heat. Stronger grades are far more hazardous and need dedicated storage, so most is sold at 70% or less.","inputs":[]},{"name":"Stabilize and ship","process":"fill","text":"A stabilizer goes in, the liquid is kept weakly acidic, and it travels in containers that shut out light. Light and organic matter speed its breakdown into water and oxygen. The bottle at a pharmacy holds just 3 to 6 percent.","inputs":[]}],"facts":["In its pure form hydrogen peroxide is a very pale blue liquid.","One milliliter of a 20-volume solution releases twenty milliliters of oxygen gas when it fully decomposes.","Annual production rose from 35,000 tonnes in 1950 to 2.7 million tonnes by 1998."],"where":[],"whereNote":null,"sources":[{"title":"Hydrogen peroxide","url":"https://en.wikipedia.org/wiki/Hydrogen_peroxide"},{"title":"Anthraquinone process","url":"https://en.wikipedia.org/wiki/Anthraquinone_process"},{"title":"Hydrogen peroxide (Britannica)","url":"https://www.britannica.com/science/hydrogen-peroxide"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ibuprofen","name":"Ibuprofen","kind":"product","category":"body-health","title":"How ibuprofen is made","url":"https://assemblyline.org/make/ibuprofen","stations":5,"upstream":5,"downstream":0,"depth":3,"dek":"Ibuprofen was invented by Boots in Nottingham, and its name is a mash-up of its three chemical groups.","answer":"Ibuprofen is made in a chemical plant from the starting chemical isobutylbenzene. The original Boots route took six steps, and a cleaner three-step route was developed in the 1980s. The purified powder is then mixed with inactive ingredients, compressed into tablets and coated.","aka":["Advil","Motrin","Nurofen","Brufen"],"inputs":["acetic-anhydride"],"uses":[],"grounds":["natural-gas","water"],"upstreamSlugs":["acetic-anhydride","methanol","carbon-monoxide","natural-gas","water"],"downstreamSlugs":[],"steps":[{"name":"Build the molecule","process":"react","text":"The original Boots synthesis started from isobutylbenzene and took six steps. A greener route developed at the Celanese Chemical Company in the 1980s takes three steps and creates less waste.","inputs":["acetic-anhydride"],"spec":"3 steps in the modern route"},{"name":"Purify the powder","process":"refine","text":"The product of the last step is purified until it meets the standard for medicine.","inputs":[]},{"name":"Blend with excipients","process":"mix","text":"The active powder is mixed with inactive ingredients such as fillers, binders, disintegrants and lubricants that make the powder flow and the tablet break up in the body.","inputs":[]},{"name":"Press the tablets","process":"press","text":"Tablet presses compress the dry, free-flowing powder into tablets in dies, each with an accurate dose.","inputs":[]},{"name":"Coat and pack","process":"coat","text":"The tablets are coated so they are easier to swallow, then packed in blister packs or bottles.","inputs":[]}],"facts":["Ibuprofen was discovered in 1961 in Nottingham by Stewart Adams and John Nicholson at Boots.","The name comes from its three groups: isobutyl, propionic acid and phenyl.","In 1983 and 1984 it became the first NSAID besides aspirin to be sold over the counter in the UK and the US."],"where":[],"whereNote":null,"sources":[{"title":"Ibuprofen","url":"https://en.wikipedia.org/wiki/Ibuprofen"},{"title":"Tablet (pharmacy)","url":"https://en.wikipedia.org/wiki/Tablet_(pharmacy)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ice-cream","name":"Ice cream","kind":"product","category":"food","title":"How ice cream is made","url":"https://assemblyline.org/make/ice-cream","stations":7,"upstream":20,"downstream":0,"depth":6,"dek":"Ice cream is a foam of air, ice crystals and fat globules, frozen while it is being whipped.","answer":"A factory blends milk, cream, sugar and stabilizers, pasteurizes and homogenizes the mix, and ages it cold. The mix is then frozen in a scraped-surface freezer that whips in air while ice crystals form. The soft ice cream gets flavors and swirls, is filled into containers, and is hardened in a blast freezer.","aka":["gelato","frozen custard","soft serve"],"inputs":["pasteurized-milk","sugar","cream","vanilla-extract"],"uses":[],"grounds":["raw-milk","sugarcane","sugar-beet","water","vanilla-pods","limestone","corn","natural-gas","crude-oil"],"upstreamSlugs":["pasteurized-milk","sugar","cream","vanilla-extract","raw-milk","sugarcane","sugar-beet","water","lime","vanilla-pods","ethanol","limestone","corn","yeast","ethylene","molasses","naphtha","natural-gas","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Blend the mix","process":"mix","text":"Milk, cream, sugar and small amounts of stabilizer and emulsifier are blended in a big tank. The result is an oil-in-water emulsion that will turn into a foam when frozen.","inputs":["pasteurized-milk","sugar","cream"]},{"name":"Homogenize it","process":"mold","text":"The mix is forced through a narrow gap at high pressure, which breaks the fat globules into tiny droplets. Smaller droplets give a smooth body that does not feel greasy.","inputs":[]},{"name":"Pasteurize the mix","process":"pasteurize","text":"The mix is heated to kill pathogens, then pumped on to the next step while still warm.","inputs":[]},{"name":"Age the mix cold","process":"chill","text":"The mix rests in a cooled tank for hours. Stabilizers hydrate and fats begin to crystallize, which helps it hold air and melt slowly.","inputs":[]},{"name":"Whip and freeze at once","process":"chill","text":"In a continuous freezer, the mix runs through a chilled barrel while blades scrape it off the wall. Air is pumped in, and ice crystals form small. The product leaves as soft, thick cream at a temperature below the freezing point of water.","inputs":[]},{"name":"Fold in flavor","process":"mix","text":"Vanilla, chocolate, fruit sauces and cookie pieces are added through a feeder as the soft ice cream flows toward the filler.","inputs":["vanilla-extract"]},{"name":"Fill and harden","process":"fill","text":"Containers are filled and sent through a blast freezer or a hardening tunnel so the center freezes solid fast. Fast freezing keeps the ice crystals small and the texture smooth.","inputs":[]}],"facts":["Hannah Glasse's 1751 cookbook The Art of Cookery included a recipe that told the cook to add a handful of salt to the ice.","Salt makes ice colder as it melts, which is how cream could first be frozen and not merely chilled.","Soft ice cream has more air mixed in than hard ice cream, which cuts its cost."],"where":[],"whereNote":null,"sources":[{"title":"Ice cream","url":"https://en.wikipedia.org/wiki/Ice_cream"},{"title":"Milk","url":"https://en.wikipedia.org/wiki/Milk"},{"title":"Basic principles of ice cream manufacture in industry","url":"https://extra.shu.ac.uk/foodtechnology/ice%20cream%20maker.html"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ice-skates","name":"Ice skates","kind":"product","category":"play","title":"How ice skates are made","url":"https://assemblyline.org/make/ice-skates","stations":8,"upstream":73,"downstream":0,"depth":8,"dek":"The boot of a figure skate can take as many as 125 separate production steps.","answer":"An ice skate has two halves built separately. Leather and synthetics are cut for the boot, stitched, and stretched over a foot-shaped mold called a last. Steel for the blade is ground with a shallow hollow along the bottom that makes two edges, then screwed to the sole.","aka":["figure skates","hockey skates","skates"],"inputs":["leather","thread","adhesive","steel","stainless-steel","chromium","screw"],"uses":[],"grounds":["cattle-hide","rock-salt","water","chromite","limestone","air","crude-oil","iron-ore","dolomite","manganese-ore","natural-gas","nickel-ore","coal","trona","zinc-ore","sulfur","quartz","timber","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["leather","thread","adhesive","steel","stainless-steel","chromium","screw","cattle-hide","rock-salt","water","lime","polyester","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","pig-iron","magnesium","steel-scrap","oxygen","manganese","argon","nickel","chromite","coke","soda-ash","limestone","air","aluminum","steel-wire","zinc","pet-plastic","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","iron-ore","dolomite","silicon","propane","manganese-ore","natural-gas","nickel-ore","coal","carbon-dioxide","trona","petroleum-coke","alumina","zinc-ore","p-xylene","ethylene-glycol","naphtha","sulfur","benzene","quartz","charcoal","timber","corn","yeast","bauxite","toluene","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the boot pieces","process":"cut","text":"Machines cut the leather and other materials into the parts of the upper and its lining, along with the heel, tongue and reinforcements. Boots today are often a mix of leather and synthetics.","inputs":["leather"]},{"name":"Stitch and cement the upper","process":"sew","text":"The fitting department stitches and glues the components of the upper together. Eyelet holes are punched for the laces, and the material is softened so it can be worked.","inputs":["thread","adhesive"]},{"name":"Stretch it over a last","process":"mold","text":"The upper is pulled tight around a last, a molded wooden or plastic foot form. This step sets the skate's final size, width and shape, which makes it one of the most important in the whole process.","inputs":[]},{"name":"Fit the outsole and heel","process":"assemble","text":"The finish is removed from the bottom of the lasted upper, a step called roughing, so the outsole will stick. The outsole and heel are attached and trimmed to match the skate.","inputs":["leather","adhesive"]},{"name":"Temper and coat the blade","process":"coat","text":"Blades usually come from an outside maker, in carbon or stainless steel. The steel is tempered and often chromed, and stainless blades for skilled skaters may get a titanium compound that cuts friction against the ice.","inputs":["steel","stainless-steel","chromium"]},{"name":"Grind the hollow edge","process":"grind","text":"Grinding leaves the bottom of the blade slightly concave along its whole length, with two sharp edges that are what actually touch the ice.","inputs":[]},{"name":"Screw the blade on","process":"assemble","text":"The blade is screwed to the sole and the laces are added. On figure skates the front of the blade carries saw-toothed picks that skaters use for jumps like the Lutz.","inputs":["screw"]},{"name":"Polish and test the pair","process":"inspect","text":"The finished skate is polished and checked in a last inspection, then packed.","inputs":[]}],"facts":["The first ice skates were made from the leg bones of horses, oxen or deer and tied to the feet with leather straps.","In the 13th century, Dutch skaters began sharpening steel blades, so people could push with their legs instead of using a pole.","Because of the hollow ground along its length, a skater is always balanced on a pair of tiny blades."],"where":[],"whereNote":null,"sources":[{"title":"Ice skate","url":"https://en.wikipedia.org/wiki/Ice_skate"},{"title":"Behind the Scenes at Riedell: How Ice Skates Are Made","url":"https://ice-blog.riedellskates.com/behind-the-scenes-at-riedell-how-figure-skates-are-made/"},{"title":"Skating through production","url":"https://tomorrowsworldtoday.com/?p=4428"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"imitation-crab","name":"Imitation crab","kind":"product","category":"food","title":"How imitation crab is made","url":"https://assemblyline.org/make/imitation-crab","stations":7,"upstream":13,"downstream":0,"depth":3,"dek":"Imitation crab is pollock fish paste, set with heat into strands and painted red on the outside.","answer":"Pollock spoils fast, so the fish is beheaded, gutted and stripped from skin and bone, then minced and washed in cold water until little but protein is left. That surimi freezes well. Later it is mixed with starch, egg white and flavor, extruded as a sheet, heated, slit into strips, folded into a rope and wrapped in red paste.","aka":["crab sticks","surimi","seafood sticks","krab","kanikama"],"inputs":["whitefish","water","sugar","table-salt","corn-starch","eggs"],"uses":[],"grounds":["whitefish","water","eggs","sugarcane","sugar-beet","rock-salt","seawater","corn","limestone"],"upstreamSlugs":["whitefish","water","sugar","table-salt","corn-starch","eggs","sugarcane","sugar-beet","lime","rock-salt","seawater","corn","limestone"],"downstreamSlugs":[],"steps":[{"name":"Bone and mince the pollock","process":"separate","text":"The fish are beheaded, gutted and washed. A machine separates flesh from skin and bone, and the meat is pushed through a drum with small holes.","inputs":["whitefish"]},{"name":"Wash it repeatedly","process":"wash","text":"Cold water carries away enzymes, blood and fat, including the system that would otherwise generate formaldehyde and turn frozen pollock rubbery. What remains is nearly pure fish protein.","inputs":["water"]},{"name":"Protect for freezing","process":"mix","text":"Sugar and salt go in as cryoprotectants, so the paste keeps its gel-forming power through a year of frozen storage. At this point it is surimi.","inputs":["sugar","table-salt"]},{"name":"Blend starch and egg","process":"mix","text":"Spices, flavoring, starch and egg white are mixed in. Starch improves the texture, and egg white makes the paste stronger, glossier and whiter. Now it is called kamaboko.","inputs":["corn-starch","eggs"]},{"name":"Extrude and heat a sheet","process":"cook","text":"A wide, flat nozzle lays the paste out as a sheet, and a brief heating makes it stronger and more elastic.","inputs":[]},{"name":"Slit and fold the strips","process":"cut","text":"Blades cut the sheet into a row of strips but not all the way through, like barely attached noodles. The strips fold up into a rope with lengthwise fibers, like muscle.","inputs":[]},{"name":"Wrap in red paste","process":"coat","text":"A very thin layer of reddish surimi wraps the rope, copying the color of crabmeat near the shell. It is cooked and cut to length. Chunk-style pieces use wider strips, cut at an angle.","inputs":[]}],"facts":["The Japanese company Sugiyo first produced and patented imitation crab flesh in 1974.","In 1969 a researcher found that sucrose acted as a cryoprotectant for surimi, letting it survive freezing.","Two to three million tons of fish a year go into surimi and surimi products, about 2 to 3 percent of world fisheries supply."],"where":[],"whereNote":null,"sources":[{"title":"Alaska Science Forum, University of Alaska Fairbanks: Better seafood through chemistry","url":"https://www.gi.alaska.edu/alaska-science-forum/better-seafood-through-chemistry"},{"title":"Surimi","url":"https://en.wikipedia.org/wiki/Surimi"},{"title":"Crab stick","url":"https://en.wikipedia.org/wiki/Crab_stick"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"light-bulb","name":"Incandescent light bulb","kind":"product","category":"minerals","title":"How incandescent light bulbs are made","url":"https://assemblyline.org/make/light-bulb","stations":7,"upstream":22,"downstream":0,"depth":6,"dek":"By the 1970s, just 15 ribbon machines made every incandescent bulb in the world.","answer":"An incandescent bulb is a glass envelope around a coiled tungsten filament. A ribbon machine blows the glass bulbs from a moving ribbon of molten glass. The filament is drawn from tungsten, coiled, and mounted on a glass stem with lead-in wires. The bulb is sealed, pumped out or filled with inert gas, and capped with a base.","aka":["light bulb","incandescent lamp","tungsten bulb"],"inputs":["glass","tungsten","nitrogen","argon"],"uses":[],"grounds":["silica-sand","limestone","tungsten-ore","air","rock-salt","water","trona","natural-gas","corn","sugarcane","sugar-beet"],"upstreamSlugs":["glass","tungsten","nitrogen","argon","silica-sand","soda-ash","limestone","tungsten-ore","hydrogen","air","rock-salt","water","ammonia","carbon-dioxide","lime","trona","natural-gas","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Blow bulbs from a ribbon","process":"blow","text":"A continuous ribbon of glass rides a conveyor through a furnace. Aligned air nozzles blow it down through holes in the belt into molds below. A typical machine makes 50,000 to 120,000 bulbs an hour.","inputs":["glass"],"spec":"50,000–120,000 bulbs an hour"},{"name":"Draw the tungsten wire","process":"draw","text":"Sintered tungsten was made ductile in 1906 by William D. Coolidge, so it could be drawn into the fine wire used for filaments.","inputs":["tungsten"]},{"name":"Coil the filament","process":"machine","text":"The wire is wound into a coil, and in a coiled-coil bulb that coil is wound into a second coil on a mandrel. Coiling packs a long filament into a small space.","inputs":[]},{"name":"Mount it on the stem","process":"assemble","text":"The filament is held on a glass stem with small support wires, and contact wires run through the glass without letting air or gas leak.","inputs":[]},{"name":"Pump out, fill and seal","process":"fill","text":"The bulb is either evacuated or filled with inert gas to protect the filament from oxidation. Irving Langmuir found that inert gas, nitrogen at first and later argon, doubled the light per watt and reduced blackening.","inputs":["nitrogen","argon"]},{"name":"Cap the base","process":"assemble","text":"A base with two or more conductors carries current from the socket to the filament.","inputs":[]},{"name":"Burn-test the lamp","process":"inspect","text":"Bulbs are checked for light and life. Designers trade efficiency against longevity, typically setting life at 1,000 to 2,000 hours for general lighting.","inputs":[],"spec":"1,000–2,000 hours"}],"facts":["Less than 5% of the energy a typical incandescent bulb uses becomes visible light, and the rest is released as heat.","A glowing filament runs at 2,000 to 3,300 K, below tungsten's melting point of 3,695 K.","By 1939 the Ribbon Machine at Corning was producing 1,000 bulbs per minute, compared with around 150 bulbs per hour blown by hand in the 1880s."],"where":[],"whereNote":null,"sources":[{"title":"Incandescent light bulb","url":"https://en.wikipedia.org/wiki/Incandescent_light_bulb"},{"title":"Glass production","url":"https://en.wikipedia.org/wiki/Glass_production"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"incense","name":"Incense","kind":"product","category":"body-health","title":"How incense is made","url":"https://assemblyline.org/make/incense","stations":5,"upstream":4,"downstream":0,"depth":2,"dek":"Incense that smolders on its own contains a fuel such as charcoal or wood powder, mixed in with the perfume.","answer":"Incense is made by grinding fragrant woods, barks, herbs and resins to powder and mixing them with a binder and water into a paste. The paste is shaped by extruding, pressing or coating it onto a stick, then cut and dried. Direct-burning types also carry a fuel such as charcoal or wood powder so they keep glowing.","aka":["joss sticks","agarbatti","incense sticks"],"inputs":["timber","charcoal","water","bamboo"],"uses":[],"grounds":["timber","water","bamboo"],"upstreamSlugs":["timber","charcoal","water","bamboo"],"downstreamSlugs":[],"steps":[{"name":"Collect resins and woods","process":"harvest","text":"Fragrant materials such as frankincense and myrrh resin, woods, barks and leaves are gathered. Frankincense trees begin producing resin at about eight to ten years old and are tapped two to three times a year.","inputs":["timber"]},{"name":"Grind to powder","process":"grind","text":"The raw materials are powdered. Oily resins are balanced with dry wood, bark and leaf powders, since too much oil stops the incense from smoldering.","inputs":[]},{"name":"Mix with binder and water","process":"mix","text":"A paste is made with a binder such as makko, from the bark of Persea trees, or a gum such as gum arabic. For direct-burning types, charcoal or wood powder supplies the fuel. Too much water or too much compression makes the stick burn unevenly.","inputs":["charcoal","water"]},{"name":"Shape the paste","process":"extrude","text":"The paste is extruded into sticks or coils, pressed into forms, or coated thickly onto a bamboo core. A cored stick burns away with its core, and a coil can burn for hours to days.","inputs":["bamboo"]},{"name":"Cut and dry","process":"dry","text":"Paste cut into pieces is dried until hard, so the sticks can be handled and burn evenly.","inputs":[]}],"facts":["Resin balls found in prehistoric tombs at El Mahasna show that ancient Egyptians burned incense.","Incense has been used as a clock, because a coil or stick burns at a steady pace.","Dhoop, solid incense with no core, is the most common form made in Japan and Tibet."],"where":[],"whereNote":null,"sources":[{"title":"Incense","url":"https://en.wikipedia.org/wiki/Incense"},{"title":"Frankincense","url":"https://en.wikipedia.org/wiki/Frankincense"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"indigo-plant","name":"Indigo","kind":"raw","category":"farm","title":"How indigo dye is made from plants","url":"https://assemblyline.org/make/indigo-plant","stations":3,"upstream":0,"downstream":2,"depth":0,"dek":"The blue in a living indigo vat is born yellow and turns blue only when it meets air.","answer":"True indigo is a shrub whose leaves contain a colorless compound called indican. Soaking cut leaves in a vat for 12 to 15 hours releases it, and it turns into a yellow soluble form. Cloth dipped in that vat comes out yellow-green and turns blue as the air hits it.","aka":["true indigo","natural indigo","Indigofera tinctoria"],"inputs":[],"uses":["denim"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["denim","jeans"],"steps":[{"name":"Cut the leafy shrubs","process":"harvest","text":"Indigofera tinctoria is a shrub one to two meters high with light green leaves. Leaves hold between 0.2 and 0.8 percent of the colorless precursor, so a lot of foliage is needed.","inputs":[],"spec":"0.2 to 0.8% indican in leaves"},{"name":"Soak the leaves in a vat","process":"ferment","text":"Pressed into a vat and soaked, the leaves release the precursor. After 12 to 15 hours of fermentation the liquid holds the yellow, water-soluble leucoindigo.","inputs":[],"spec":"12 to 15 hours"},{"name":"Air it blue","process":"react","text":"Exposure to oxygen turns the yellow liquid into insoluble blue indigo. The pigment is collected as a paste, which can be dried into cakes.","inputs":[]}],"facts":["Most indigo today is synthetic, about 80,000 tonnes each year as of 2023.","A pair of blue jeans uses only 3 to 12 grams of indigo.","Blue colorants are relatively rare in nature, which is part of why indigo was so prized."],"where":[],"whereNote":null,"sources":[{"title":"Indigo dye","url":"https://en.wikipedia.org/wiki/Indigo_dye"},{"title":"Indigofera tinctoria","url":"https://en.wikipedia.org/wiki/Indigofera_tinctoria"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"indium","name":"Indium","kind":"material","category":"electronics","title":"How indium is recovered","url":"https://assemblyline.org/make/indium","stations":5,"upstream":5,"downstream":14,"depth":2,"dek":"Indium is about as scarce as silver, and all of it is a by-product of refining other metals, chiefly zinc.","answer":"Indium forms no mineable deposits of its own. It is recovered from sulfidic zinc ores, where it rides along in the mineral sphalerite. During the roast-leach-electrowinning route for zinc, indium builds up in the iron-rich residues, and refiners then extract it. LCD screens use about half of it.","aka":["In","indium metal"],"inputs":["zinc-ore","sulfuric-acid"],"uses":["led","indium-tin-oxide"],"grounds":["zinc-ore","sulfur","air","water"],"upstreamSlugs":["zinc-ore","sulfuric-acid","sulfur","air","water"],"downstreamSlugs":["led","indium-tin-oxide","led-bulb","lcd-screen","television","computer-mouse","pinball-machine","e-reader","remote-control","oled-screen","laptop","smartwatch","digital-camera","smartphone"],"steps":[{"name":"Roast the zinc concentrate","process":"fire","text":"Zinc ore concentrate is roasted. Indium travels with the zinc through the early steps.","inputs":["zinc-ore"]},{"name":"Leach with acid","process":"react","text":"The roasted material is dissolved in acid so the zinc can be recovered by electrowinning. Not everything dissolves.","inputs":["sulfuric-acid"]},{"name":"Collect it in the residue","process":"separate","text":"Indium accumulates in the iron-rich residues left from zinc leaching. These residues are the feedstock for indium refiners.","inputs":[]},{"name":"Refine to metal","process":"refine","text":"Indium is separated from the residue and refined to a soft, silvery metal. Output is limited by how much zinc ore is mined each year.","inputs":[]},{"name":"Cast into ingots","process":"cast","text":"The refined metal is melted and cast into ingots for sale to display makers.","inputs":[]}],"facts":["Indium sits at about 50 parts per billion in Earth's crust, a similar abundance to silver.","LCD screens account for about half of indium consumption.","The first large-scale use of indium was coating bearings in World War II aircraft engines."],"where":[{"place":"China","share":"290 tonnes"},{"place":"South Korea","share":"195 tonnes"},{"place":"Japan","share":"70 tonnes"},{"place":"Canada","share":"65 tonnes"}],"whereNote":"2016 indium output (Wikipedia).","sources":[{"title":"Indium","url":"https://en.wikipedia.org/wiki/Indium"},{"title":"Indium tin oxide","url":"https://en.wikipedia.org/wiki/Indium_tin_oxide"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"indium-tin-oxide","name":"Indium tin oxide","kind":"material","category":"electronics","title":"How indium tin oxide coatings are made","url":"https://assemblyline.org/make/indium-tin-oxide","stations":7,"upstream":36,"downstream":7,"depth":8,"dek":"A film of this oxide carries current yet lets light through, so a touch screen can work without hiding the picture.","answer":"Indium tin oxide is typically about 74 percent indium, 8 percent tin and 18 percent oxygen by weight. Makers press mixed oxide powders into a plate, sinter it hard and machine it into a sputtering target. In a vacuum chamber, gas ions knock material off that target and onto glass, leaving a clear film that conducts electricity.","aka":["ITO","transparent conductive oxide"],"inputs":["indium","tin","glass","photoresist"],"uses":["lcd-screen","oled-screen"],"grounds":["zinc-ore","tin-ore","silica-sand","limestone","sulfur","air","water","coal","rock-salt","trona","natural-gas","corn","crude-oil","sugarcane","sugar-beet"],"upstreamSlugs":["indium","tin","glass","photoresist","zinc-ore","sulfuric-acid","tin-ore","coke","silica-sand","soda-ash","limestone","phenolic-resin","sulfur","air","water","coal","rock-salt","ammonia","carbon-dioxide","lime","trona","phenol","formaldehyde","natural-gas","corn","yeast","benzene","propylene","methanol","molasses","naphtha","hydrogen","toluene","crude-oil","sugarcane","sugar-beet"],"downstreamSlugs":["lcd-screen","oled-screen","laptop","television","smartwatch","digital-camera","smartphone"],"steps":[{"name":"Mix the two powders","process":"mix","text":"Indium oxide and tin oxide powders are blended, in patent examples at weight ratios of 95:5 and 90:10. Ball mills are one tool for the job. Getting the two oxides to react fully avoids unwanted phases that disturb coating later.","inputs":["indium","tin"]},{"name":"Press a green compact","process":"press","text":"The powder is press-molded into a plate at ordinary temperature. This fragile block, called a green compact, holds its shape until the furnace.","inputs":[]},{"name":"Sinter the plate hard","process":"fire","text":"These oxides resist sintering. In ordinary air firing, the plate reaches only about 60 to 70% of theoretical density, and a low-density target sputters slowly and sheds dust. Hot pressing reaches about 94% but costs far more, and one patent uses pressurized oxygen instead.","inputs":[],"spec":"1,250 to 1,650 °C"},{"name":"Grind and cut the target","process":"grind","text":"In one patent's examples, a surface grinder flattens the sintered body and a diamond cutter trims its sides. The finished piece is the source of atoms for the coating machine.","inputs":[]},{"name":"Sputter onto glass","process":"deposit","text":"In a vacuum chamber, inert gas ions strike the target and knock material onto the glass as a thin film. Sputtering won out because it covers large areas and repeats well. Electron beam evaporation is another route.","inputs":["glass"]},{"name":"Balance clarity and conductivity","process":"inspect","text":"Thicker films carry more current but pass less light, so every coating is a compromise. A thin film can transmit more than 80% of visible light.","inputs":[]},{"name":"Etch fine patterns","process":"etch","text":"Photoresist masks the film, and etching cuts it into precise lines and pads. These become the transparent wiring of a display or touch panel. Precise etching is the main edge this material holds over aluminum-doped zinc oxide in LCDs.","inputs":["photoresist"]}],"facts":["Few transparent conductors are as widely used as this one.","It is also used on glass doors of supermarket freezers and on architectural windows.","A coating of it gives the F-22 Raptor's canopy a gold tint while absorbing radar waves and reflecting infrared."],"where":[],"whereNote":null,"sources":[{"title":"Indium tin oxide","url":"https://en.wikipedia.org/wiki/Indium_tin_oxide"},{"title":"Photoresist","url":"https://en.wikipedia.org/wiki/Photoresist"},{"title":"US5094787A, Method of manufacturing ITO sputtering target","url":"https://patents.google.com/patent/US5094787"},{"title":"US5435826A, Sputtering target and method for producing same","url":"https://patents.google.com/patent/US5435826"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"inflatable-pool-toy","name":"Inflatable pool toy","kind":"product","category":"play","title":"How inflatable pool toys are made","url":"https://assemblyline.org/make/inflatable-pool-toy","stations":7,"upstream":22,"downstream":0,"depth":6,"dek":"A pool float is flat vinyl panels fused at the seams by a high-frequency electric field, with no glue or stitching.","answer":"Most pool toys are thin PVC vinyl. Two flat sheets are cut to size, a flat strip valve is welded inside one of them, and the pair goes under a welding die shaped like the toy. A high-frequency electric field heats the plastic from within until the layers melt together along the seam. Excess is trimmed, and the toy gets inflated for a test.","aka":["pool float","inflatable toy","pool floatie","air mattress"],"inputs":["pvc"],"uses":[],"grounds":["water","natural-gas","rock-salt","iron-ore","sulfur","air","crude-oil","titanium-ore","coal"],"upstreamSlugs":["pvc","ethylene","chlorine","water","pigment","plasticizer","naphtha","natural-gas","rock-salt","sulfuric-acid","iron-ore","titanium-dioxide","carbon-black","sulfur","air","propylene","crude-oil","hydrogen","titanium-ore","coke","oxygen","coal"],"downstreamSlugs":[],"steps":[{"name":"Roll out the vinyl sheet","process":"roll","text":"Polyvinyl chloride, often called vinyl, is the most common material for pool floats and air mattresses, because it is cheap, durable and water-resistant. It is made into thin flexible sheet.","inputs":["pvc"]},{"name":"Cut the panels","process":"cut","text":"Flat sheets are cut to the size the toy requires. They usually run about 0.18 to 0.35 millimeters thick, and their edges become the future seams.","inputs":[]},{"name":"Weld in the valve","process":"weld","text":"One patent builds a one-way valve from two heat-weldable strips joined into a flat tube. It is welded to the inner face of one sheet before the toy closes up, and a non-weldable coating inside stops the weld from sealing its opening.","inputs":["pvc"]},{"name":"Stack under the die","process":"assemble","text":"One sheet is laid over the other under a high-frequency welding machine, whose die follows the outline of the finished toy.","inputs":[]},{"name":"Weld the seams","process":"weld","text":"The die comes down and clamps the sheets between a pair of electrodes. A high-frequency field excites the molecules in the plastic, which heats from inside and fuses under pressure. The clamp holds until the joint hardens.","inputs":[]},{"name":"Trim the flange","process":"cut","text":"Excess vinyl outside the seam is cut away, either by a cutting die built into the welding machine or after the shell comes out.","inputs":[]},{"name":"Inflate and test","process":"inspect","text":"The airtight toy is inflated and checked, since the material must not let air leak through the seams.","inputs":[]}],"facts":["Radio-frequency welding only works on plastics whose molecules carry an electrical dipole, such as PVC.","For heavy-duty inflatables, panels of coated nylon or polyester are stitched and then sealed with glue or seam tape, because stitching leaves thousands of tiny holes.","The welded flange that sticks out around a pool float is a cheap and fairly weak seam, and it wears by catching on things."],"where":[],"whereNote":null,"sources":[{"title":"US6558498, Process of fabricating an inflatable item","url":"https://patents.google.com/patent/US6558498"},{"title":"US6027394, One way valve for inflatables and process for production","url":"https://patents.google.com/patent/US6027394"},{"title":"Radio frequency welding","url":"https://en.wikipedia.org/wiki/Radio_frequency_welding"},{"title":"What are inflatables made of?, EngineerFix","url":"https://engineerfix.com/what-are-inflatables-made-of-from-pvc-to-tpu/"},{"title":"Inflatable construction, Newport Vessels","url":"https://newportvessels.com/blogs/blog/inflatable-construction"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ink","name":"Ink","kind":"material","category":"chemicals","title":"How ink is made","url":"https://assemblyline.org/make/ink","stations":8,"upstream":37,"downstream":135,"depth":7,"dek":"Ink is color ground into a liquid fine enough to pass through a printing press without clogging it.","answer":"Printing ink starts with pigment wetted by a varnish of resin and oil, using rotating blades to build a thick mill base. Shot mills or three-roll mills then break up the clumps, sometimes over three passes. More varnish and additives thin the base to press strength. Bag filters catch oversize particles, and each batch is tested for tack and fineness.","aka":["printing ink","printer ink","writing ink"],"inputs":["vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol"],"uses":["syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella"],"grounds":["water","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","coal","natural-gas","sugar-beet"],"upstreamSlugs":["vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","ethylene","hydrogen","benzene","propylene","methanol","rock-salt","coal","molasses","naphtha","natural-gas","toluene","sugar-beet"],"downstreamSlugs":["syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","vacuum-cleaner","electric-kettle","cotton-candy","pillow","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","car","electric-car","soap","toothpaste","detergent","nitrile-glove","washing-machine","paperclip","donut","corn-flakes","popcorn","crayon","fireworks","candle","salsa","fish-sticks","zip-bag","blender","dishwasher","cotton-swab","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","refrigerator","microwave-oven","pencil","scissors","mirror","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","padlock"],"steps":[{"name":"Ready the varnish","process":"mix","text":"Resin and oil or solvent form the clear vehicle that carries the pigment. A sheetfed offset ink might use a long-oil alkyd or phenolic litho varnish.","inputs":["vegetable-oil","phenolic-resin"]},{"name":"Wet the pigment","process":"mix","text":"Rotating blades force varnish into clumps of dry pigment, and more oil and resin make a mill base. Carbon black gives black and titanium dioxide gives white.","inputs":["carbon-black","titanium-dioxide","pigment"]},{"name":"Or flush wet presscake","process":"mix","text":"Flush pigments skip dry clumping. Varnish added to wet pigment presscake displaces the water, which is poured off, and a heavy mixer works the stiff mass. Such inks need much less premixing.","inputs":[]},{"name":"Grind in a shot mill","process":"grind","text":"The base is forced through a chamber where rotating disks drive metal pellets through it, breaking up clumps. Waxes and driers often join here.","inputs":[]},{"name":"Shear on three rolls","process":"grind","text":"Stiff paste inks go between rolls turning at different speeds, and a doctor blade takes the ink off the fastest one. Hard pigments can need up to three passes. Skimping saves money but costs color strength and can wear printing plates.","inputs":[]},{"name":"Thin it to press strength","process":"mix","text":"Base ink is let down with more varnish, wax compound, solvent and additives. One patent turns about 216 parts of base into 833 parts of press-ready ink. Inks for inkjet cartridges are thinned much further with water or alcohol.","inputs":["water","ethanol"]},{"name":"Filter out oversize grit","process":"separate","text":"Bag filters with shrinking pores, starting at 150 microns, trap oversized particles. A magnetic filter may be added for metal fragments.","inputs":[]},{"name":"Test tack and grind","process":"inspect","text":"Technicians measure tack, fineness of grind and how fast the ink picks up water. Only then does it go off for packing.","inputs":[]}],"facts":["The earliest Chinese inksticks date to around 256 BC, and they were made from soot and animal glue.","Egyptian red and black inks used iron and ocher as pigments, with lead as a drier."],"where":[],"whereNote":null,"sources":[{"title":"Ink Manufacture, ZXC Print","url":"https://www.zxcprint.com/printing-knowledge/ink-manufacture.html"},{"title":"US4664710A, Direct process for the production of printing inks","url":"https://patents.google.com/patent/US4664710/en"},{"title":"Ink","url":"https://en.wikipedia.org/wiki/Ink"},{"title":"Pigment","url":"https://en.wikipedia.org/wiki/Pigment"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"inkjet-printer","name":"Inkjet printer","kind":"product","category":"electronics","title":"How inkjet printers are made","url":"https://assemblyline.org/make/inkjet-printer","stations":6,"upstream":102,"downstream":0,"depth":9,"dek":"An inkjet printhead fires droplets of ink one at a time, either by heating the ink or by squeezing a crystal.","answer":"An inkjet printer is built around a printhead with rows of tiny nozzles that propel droplets of ink onto paper. A heater or a piezoelectric crystal behind each nozzle forces out one drop on demand. The printhead rides on a belt-driven carriage, with rollers feeding the paper and a circuit board running it all.","aka":["ink printer","bubble jet printer","desktop printer"],"inputs":["silicon-wafer","abs-plastic","polystyrene","steel","electric-motor","rubber","ink","printed-circuit-board","microchip","solder","paper"],"uses":[],"grounds":["quartz","air","natural-latex","sulfur","water","kaolin","limestone","crude-oil","natural-gas","iron-ore","dolomite","manganese-ore","soybeans","rapeseed","clay","titanium-ore","corn","sugarcane","copper-ore","silica-sand","tin-ore","coal","gold-ore","lead-ore","silver-ore","zinc-ore","timber","rock-salt","trona","bauxite","sugar-beet"],"upstreamSlugs":["silicon-wafer","abs-plastic","polystyrene","steel","electric-motor","rubber","ink","printed-circuit-board","microchip","solder","paper","polysilicon","quartz","argon","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","sheet-steel","copper-wire","epoxy","ball-bearing","natural-latex","synthetic-rubber","carbon-black","sulfur","vegetable-oil","phenolic-resin","titanium-dioxide","water","ethanol","copper","fiberglass","photoresist","tin","aluminum","gold","lead","silver","wood-pulp","kaolin","limestone","silicon","hydrochloric-acid","trichlorosilane","hydrogen","nitrogen","crude-oil","natural-gas","toluene","iron-ore","coke","dolomite","propane","manganese-ore","sulfuric-acid","zinc","phenol","acetone","chlorine","caustic-soda","steel-wire","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","corn","sugarcane","yeast","copper-ore","silica-sand","soda-ash","tin-ore","coal","petroleum-coke","alumina","gold-ore","lead-ore","silver-ore","zinc-ore","timber","hydrogen-peroxide","charcoal","rock-salt","methanol","molasses","carbon-dioxide","trona","bauxite","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Make the printhead","process":"etch","text":"Nozzles, ink channels and heating elements or piezo crystals are patterned onto a silicon or metal plate. The nozzles are tiny, and each channel has to be the same size or the drops will not match.","inputs":["silicon-wafer"]},{"name":"Mold the plastic frame","process":"mold","text":"Plastic pellets are melted and injected into molds to make the chassis, the paper tray, the rollers' housings and the cover.","inputs":["abs-plastic","polystyrene"]},{"name":"Fit the carriage and motors","process":"assemble","text":"A carriage that holds the printhead is mounted on a steel rod and belt, driven by a small motor. A second motor turns the rollers that pull paper through.","inputs":["steel","electric-motor","rubber"]},{"name":"Fill the ink","process":"fill","text":"Cartridges or refillable tanks are filled with liquid ink and sealed. Printers work with inks of cyan, magenta, yellow and black, which mix to make color.","inputs":["ink"]},{"name":"Populate the control board","process":"assemble","text":"A processor, memory and driver chips are soldered to a circuit board. The board fires each nozzle at the right moment as the carriage moves.","inputs":["printed-circuit-board","microchip","solder"]},{"name":"Test print","process":"inspect","text":"Each machine prints a test pattern. A scanner or a technician checks for missing nozzles, banding and paper jams before the printer is boxed.","inputs":["paper"]}],"facts":["Piezoelectric inkjet heads, using a crystal to squeeze out drops, were developed in the early 1980s.","Inkjet technology is also used in industry to deposit materials directly onto surfaces."],"where":[],"whereNote":null,"sources":[{"title":"Inkjet printing","url":"https://en.wikipedia.org/wiki/Inkjet_printing"},{"title":"Injection moulding","url":"https://en.wikipedia.org/wiki/Injection_moulding"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"insect-repellent","name":"Insect repellent","kind":"product","category":"body-health","title":"How insect repellent is made","url":"https://assemblyline.org/make/insect-repellent","stations":5,"upstream":48,"downstream":0,"depth":9,"dek":"The U.S. Army developed DEET in 1946 for soldiers, and civilians could not buy it until it was registered in 1957.","answer":"Most insect repellent is a spray or lotion built around one active ingredient made in a chemical plant. DEET, the oldest, is produced from an acid and an amine, then diluted into a base and filled into pump bottles or aerosol cans. Higher concentrations beyond 50 percent do not protect longer.","aka":["bug spray","mosquito repellent","DEET spray"],"inputs":["ethanol","aluminum-can"],"uses":[],"grounds":["corn","sugarcane","water","natural-gas","crude-oil","coal","sugar-beet","bauxite","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","rock-salt","limestone"],"upstreamSlugs":["ethanol","aluminum-can","corn","sugarcane","water","yeast","ethylene","aluminum","ink","epoxy","molasses","naphtha","natural-gas","crude-oil","coal","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","phenol","propylene","acetone","chlorine","caustic-soda","sugar-beet","hydrogen","bauxite","lime","soybeans","rapeseed","hexane","clay","formaldehyde","air","titanium-ore","coke","oxygen","sulfuric-acid","iron-ore","sulfur","benzene","rock-salt","limestone","methanol","toluene"],"downstreamSlugs":[],"steps":[{"name":"Synthesize the active","process":"react","text":"DEET is a slightly yellow oil made in a chemical plant from a toluic acid and an amine. Other actives such as icaridin are made by their own routes.","inputs":[]},{"name":"Dilute into a base","process":"mix","text":"The active is blended into a carrier. A later formulation added polymers to slow evaporation, and was registered in 1991.","inputs":["ethanol"]},{"name":"Check the batch","process":"inspect","text":"Samples are tested so the active ingredient is at the concentration printed on the label.","inputs":[]},{"name":"Fill the bottles","process":"fill","text":"The liquid goes into pump sprays, lotion bottles or aerosol cans, with concentrations ranging from under 10 percent to nearly 100 percent.","inputs":["aluminum-can"]},{"name":"Label and box","process":"package","text":"Packages are labeled with the concentration of the active ingredient, which is what sets how long the protection lasts.","inputs":[]}],"facts":["It was first tested as an agricultural insecticide before its military use began in 1946.","The American Academy of Pediatrics considers products at 10 to 30 percent DEET safe on children.","About 120 products containing DEET are registered with the EPA, from about 30 companies."],"where":[],"whereNote":null,"sources":[{"title":"Insect repellent","url":"https://en.wikipedia.org/wiki/Insect_repellent"},{"title":"DEET","url":"https://en.wikipedia.org/wiki/DEET"},{"title":"DEET (EPA)","url":"https://www.epa.gov/insect-repellents/deet"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"instant-coffee","name":"Instant coffee","kind":"product","category":"drink","title":"How instant coffee is made","url":"https://assemblyline.org/make/instant-coffee","stations":7,"upstream":3,"downstream":0,"depth":2,"dek":"Instant coffee is real coffee, brewed in a factory vat and then dried to powder so you can brew it again.","answer":"Instant coffee is brewed first and dried second. Roasted beans are ground and brewed in giant percolators into a strong extract. A factory then removes the water by freezing and vacuum-drying the extract, or by spraying it as a mist into hot air. Either way, the dry solids dissolve again in hot water.","aka":["soluble coffee","coffee crystals","freeze-dried coffee"],"inputs":["coffee","water"],"uses":[],"grounds":["water","coffee-cherries"],"upstreamSlugs":["coffee","water","coffee-cherries"],"downstreamSlugs":[],"steps":[{"name":"Grind the roasted beans","process":"crush","text":"Coffee that has been roasted in a rotating drum is cooled and ground to the size of coarse sand, so water can reach the whole bean.","inputs":["coffee"],"spec":"0.5 to 1.1 millimetres"},{"name":"Brew it by the tonne","process":"separate","text":"Industrial percolators push hot water through banks of ground coffee. Water runs at high temperature and under pressure, which frees larger carbohydrates from the bean that help the powder dry later. The spent grounds weigh about twice as much as the soluble coffee made, and can be burned for heat.","inputs":["water"],"spec":"up to 175 °C"},{"name":"Boil off the water","process":"refine","text":"The thin extract is concentrated in evaporators until it is a thick, dark syrup. Aroma compounds are captured along the way so they can go back in later.","inputs":[]},{"name":"Freeze it and mill it","process":"chill","text":"For freeze-dried instant, the extract is frozen quickly so only small ice crystals form. The frozen slab is milled into granules and sifted for an even size.","inputs":[]},{"name":"Vacuum away the ice","process":"dry","text":"In a vacuum chamber the ice sublimates, turning directly to vapor without melting. The dry granules are left behind and expand to many times their frozen volume.","inputs":[],"spec":"granules swell tenfold"},{"name":"Spray into hot air","process":"dry","text":"In the cheaper spray-dry route, the concentrate is atomized into a tower of hot air through a nozzle or a wheel spinning at about 20,000 rpm. Each droplet dries in seconds and falls as a fine, dust-sized particle.","inputs":[],"spec":"5 to 30 seconds"},{"name":"Fuse into granules","process":"mold","text":"Spray-dried dust is too fine to use, so steam sticks the particles together into larger granules. Aroma recovered earlier is added back before jars are filled.","inputs":[]}],"facts":["Instant coffee was invented in 1890 in Invercargill, New Zealand, by David Strang.","Close to 50% of the world's green coffee is used to make instant coffee, according to a 2009 paper.","The first spray-dried Nestlé product was half maltodextrin, which kept the powder from turning sticky and clumping."],"where":[],"whereNote":null,"sources":[{"title":"Instant coffee","url":"https://en.wikipedia.org/wiki/Instant_coffee"},{"title":"Freeze drying","url":"https://en.wikipedia.org/wiki/Freeze_drying"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"instant-noodles","name":"Instant noodles","kind":"product","category":"food","title":"How instant noodles are made","url":"https://assemblyline.org/make/instant-noodles","stations":7,"upstream":33,"downstream":0,"depth":9,"dek":"Instant ramen blocks are steamed, then fried for a minute or two so they rehydrate in boiling water.","answer":"Wheat flour is mixed with salty, alkaline water into a dough, rolled into thin sheets, slit into ribbons and crimped into waves. The noodles are steamed to cook the starch, cut into blocks, and then dried by flash-frying or hot air. Dehydrated blocks soften in hot water in a few minutes.","aka":["instant ramen","ramen","cup noodles","packet noodles"],"inputs":["water","table-salt","soda-ash","flour","palm-oil"],"uses":[],"grounds":["water","rock-salt","seawater","limestone","trona","wheat","oil-palm-fruit","natural-gas","air","corn","sugarcane","sugar-beet","crude-oil"],"upstreamSlugs":["water","table-salt","soda-ash","flour","palm-oil","rock-salt","seawater","ammonia","limestone","carbon-dioxide","lime","trona","wheat","vitamin-c","oil-palm-fruit","natural-gas","air","corn","yeast","corn-starch","hydrogen","sugar","plastic-bottle","molasses","sugarcane","sugar-beet","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Dissolve salt and alkali","process":"mix","text":"Salt and kansui, an alkaline mineral water, are dissolved in water. Salt strengthens the gluten, and the alkali gives the noodles their chew and slight yellow color.","inputs":["water","table-salt","soda-ash"]},{"name":"Mix and knead the dough","process":"knead","text":"The liquid is added to wheat flour, and the dough is rested so water spreads evenly, then kneaded. The water is about 30 to 38 percent of the flour weight.","inputs":["flour"]},{"name":"Roll it into a belt","process":"roll","text":"Two sheets of dough are pressed together by rollers into one belt, and the pass is repeated until it is thin. Rolling builds gluten structure and gives the noodle strength.","inputs":[]},{"name":"Slit and crimp the ribbons","process":"cut","text":"Rotating slitters cut the sheet into strands. The conveyor belt moves slower than the blades, so the strands pile into the characteristic waves.","inputs":[]},{"name":"Steam to cook the starch","process":"cook","text":"A steam tunnel gelatinizes the starch so the noodles are already cooked. This step and the frying are what let the block take up water quickly later.","inputs":[]},{"name":"Fry or blow-dry the blocks","process":"dry","text":"Cut portions are flash-fried for 1 to 2 minutes at 140 to 160 °C, dropping moisture from 30 to 50 percent to 2 to 5 percent. Air-dried noodles instead spend 30 to 40 minutes in hot air at 70 to 90 °C. Frying oil is often palm oil.","inputs":["palm-oil"],"spec":"140 to 160 °C for 1 to 2 minutes"},{"name":"Cool, pack and add flavor","process":"package","text":"Blocks are cooled, sealed in a pouch or cup with a packet of seasoning powder and oil, and counted.","inputs":[]}],"facts":["Momofuku Ando's company Nissin launched the first instant noodles, Chikin Ramen, on 25 August 1958.","Around 103 billion servings of instant noodles were eaten worldwide in 2018.","Nissin introduced Cup Noodles, the first cup version, in 1971."],"where":[],"whereNote":null,"sources":[{"title":"Instant noodles","url":"https://en.wikipedia.org/wiki/Instant_noodles"},{"title":"Pasta","url":"https://en.wikipedia.org/wiki/Pasta"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"insulin","name":"Insulin","kind":"product","category":"body-health","title":"How insulin is made","url":"https://assemblyline.org/make/insulin","stations":7,"upstream":23,"downstream":0,"depth":6,"dek":"Most insulin today is brewed by yeast or bacteria carrying a human gene.","answer":"Engineered E. coli or yeast carrying the human gene grow in stainless steel bioreactors, making a precursor called proinsulin. Bacteria must be broken open and their protein refolded, while yeast secretes it. Centrifuges, filters and several chromatography columns purify the protein, and enzymes convert it to its final form. It is then blended with buffers and filled aseptically in a cleanroom.","aka":["recombinant insulin","human insulin"],"inputs":["yeast","sugar","water","air","glass-bottle"],"uses":[],"grounds":["water","air","sugarcane","sugar-beet","silica-sand","limestone","rock-salt","trona","natural-gas","corn","crude-oil"],"upstreamSlugs":["yeast","sugar","water","air","glass-bottle","molasses","sugarcane","sugar-beet","lime","silica-sand","soda-ash","limestone","polyethylene","rock-salt","ammonia","carbon-dioxide","trona","ethylene","natural-gas","corn","naphtha","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Build the strain","process":"grow","text":"Scientists insert the human gene into E. coli or yeast, then validate the modified cells for productivity, stability and safety before scaling up.","inputs":[]},{"name":"Ferment in steel bioreactors","process":"ferment","text":"The microbe grows in stainless steel vessels while operators hold temperature, pH, dissolved oxygen and nutrient feed in tight ranges, to get as much cell growth and precursor as they can.","inputs":["yeast","sugar","water","air"]},{"name":"Harvest the precursor","process":"separate","text":"E. coli locks the protein in clumps called inclusion bodies and has to be broken open. Yeast secretes it more readily. Centrifuges and filters remove unwanted solids.","inputs":[]},{"name":"Refold and purify","process":"refine","text":"Bacterial clumps are dissolved and refolded. Precipitation and several chromatography columns then sort molecules by size, charge and how they interact with water. Ultrafiltration concentrates the result.","inputs":[]},{"name":"Cut to the final form","process":"react","text":"Enzymes or chemicals trim the precursor into human insulin or one of its rapid- or long-acting analogues, under carefully monitored conditions. A final polishing column cleans it up.","inputs":[]},{"name":"Formulate the solution","process":"mix","text":"The pure protein is mixed with buffers, preservatives and stabilizers in water for injection. Contamination is the main danger here, so utilities like pure steam have to be flawless.","inputs":["water"]},{"name":"Fill aseptically","process":"fill","text":"Sterile piping carries the solution to lines in a controlled cleanroom that fill vials, cartridges or pens. Each is inspected, labeled and packed.","inputs":["glass-bottle"]}],"facts":["Frederick Banting and Charles Best first isolated insulin from dog pancreas in 1921.","In 1951 Frederick Sanger sequenced insulin, making it the first protein to be fully sequenced.","Genentech developed the technique for the first biosynthetic human insulin, Humulin, and Eli Lilly marketed it in 1982."],"where":[],"whereNote":null,"sources":[{"title":"Boccard: Industrial insulin production explained","url":"https://www.boccard.com/?p=86757"},{"title":"Bioresources and Bioprocessing: Downstream processing of recombinant human insulin from E. coli inclusion bodies","url":"https://link.springer.com/10.1186/s40643-021-00419-w"},{"title":"Insulin","url":"https://en.wikipedia.org/wiki/Insulin"},{"title":"Insulin (medication)","url":"https://en.wikipedia.org/wiki/Insulin_(medication)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"iridium","name":"Iridium","kind":"material","category":"metals","title":"How iridium is made","url":"https://assemblyline.org/make/iridium","stations":6,"upstream":14,"downstream":0,"depth":4,"dek":"For every 190 tonnes of platinum, refiners isolate only 7.5 tonnes of this metal, which even aqua regia cannot touch.","answer":"Nobody mines for it alone. It rides along in platinum ores and in copper and nickel deposits, and it is what remains after nearly everything else has dissolved. Refiners collect the sludge from electrorefining cells, dissolve away the platinum and palladium, then force the stubborn residue into solution and drop it out as a salt that is reduced to powder.","aka":["Ir","platinum group metal","iridium metal"],"inputs":["platinum-ore","nickel-ore","copper-ore","nitric-acid","hydrochloric-acid","chlorine","ammonia","hydrogen"],"uses":[],"grounds":["platinum-ore","nickel-ore","copper-ore","air","water","rock-salt","natural-gas","sulfur"],"upstreamSlugs":["platinum-ore","nickel-ore","copper-ore","nitric-acid","hydrochloric-acid","chlorine","ammonia","hydrogen","air","water","rock-salt","sulfuric-acid","natural-gas","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Smelt the host ores","process":"melt","text":"Platinum ore from South Africa's Bushveld, and copper and nickel ores from places such as Sudbury and Norilsk, are mined and smelted for their main metals. A trace of this metal comes along, with crustal rock averaging just 0.001 ppm.","inputs":["platinum-ore","nickel-ore","copper-ore"]},{"name":"Collect the anode mud","process":"electrolyze","text":"During electrorefining of copper and nickel, noble metals do not dissolve. They settle to the bottom of the cell as anode mud, along with silver, gold, selenium and tellurium. This sludge is the starting point.","inputs":[]},{"name":"Dissolve away the platinum","process":"separate","text":"Acid treatment takes platinum and palladium into solution. This metal stays behind in the acid-insoluble residue, which is how it was found in 1803.","inputs":["nitric-acid","hydrochloric-acid"]},{"name":"Force the residue open","process":"react","text":"Refiners make the stubborn solids soluble by fusing them with sodium peroxide and extracting with acid, or by treating them with chlorine in hydrochloric acid.","inputs":["chlorine"]},{"name":"Drop out the salt","process":"separate","text":"From solution, an ammonium salt with an intense dark color is precipitated, or organic amines pull the metal out. This compound is the main intermediate in purification.","inputs":["ammonia"]},{"name":"Reduce and sinter powder","process":"fire","text":"The purified compound is reduced to a metal powder. Solid pieces are so hard and brittle that they are hard to machine or form, so powder metallurgy shapes most of the parts, such as spark plug tips and crucibles.","inputs":["hydrogen"]}],"facts":["Only about 6,800 kilograms of iridium were produced in 2023.","A layer of unusually iridium-rich clay at the Cretaceous-Paleogene boundary pointed to the impact behind the extinction of the non-avian dinosaurs.","The international prototype kilogram is an alloy of 90 percent platinum and 10 percent iridium."],"where":[],"whereNote":null,"sources":[{"title":"Iridium","url":"https://en.wikipedia.org/wiki/Iridium"},{"title":"Iridium (Britannica)","url":"https://www.britannica.com/science/iridium"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"iron-ore","name":"Iron ore","kind":"raw","category":"ground","title":"How iron ore is mined","url":"https://assemblyline.org/make/iron-ore","stations":4,"upstream":0,"downstream":264,"depth":0,"dek":"Iron is mined more than every other metal put together. Almost all of it ends up as steel.","answer":"Iron ore is rock rich in iron oxides, dug from huge open pits. The best ore can go straight to a blast furnace. Poorer ore, such as the banded rock called taconite, is crushed to powder and passed under magnets to pull out the iron, leaving a quartz-rich waste behind. Nearly all of it becomes steel.","aka":["hematite","magnetite","taconite"],"inputs":[],"uses":["lipstick","pig-iron","manganese","vanadium","pigment","ferrite"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["lipstick","pig-iron","manganese","vanadium","pigment","ferrite","steel","cast-iron-pan","car-engine","piano","dumbbell","sailboat","thermometer","lithium-ion-cell","aa-battery","wrench","toothbrush","nail-polish","mascara","pvc","abs-plastic","ink","paint","lego-brick","lcd-screen","porcelain","chalk","candy-cane","sprinkles","crayon","plastic-straw","pencil-eraser","printer-toner","billiard-ball","foundation-makeup","eyeshadow","eyeglass-frame","towel","headphones","phone-charger","loudspeaker","ev-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","usb-cable","inkjet-printer","electric-toothbrush","car","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","credit-card","plastic-wrap","garden-hose","football","volleyball","yoga-mat","action-figure","fashion-doll","globe","inflatable-pool-toy","chain-link-fence","pvc-pipe","vinyl-floor","power-cable","smoke-detector","flip-flops","vinyl-record","hearing-aid","3d-printer-filament","computer-keyboard","computer-mouse","ballpoint-pen","game-console","wifi-router","graphics-card","remote-control","syringe","plastic-bag","tin-can","aluminum-can","windshield","golf-ball","baseball","basketball","soccer-ball","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","frisbee","board-game","jigsaw-puzzle","trading-cards","candy-coated-chocolate","floor-tile","underwear","flag","compact-disc","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","mirror","electric-car","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","bowling-ball","dartboard","dice","snow-globe","coil-spring","wheelbarrow","fire-extinguisher","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","donut","blender","air-conditioner","treadmill","safety-pin","airbag","hinge","saw-blade","shovel","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","violin","clothespin","staple","sofa","slinky","cello","guitar-string","bolt","chain","light-switch","mattress","concrete","skyscraper","roller-skates","wine","bourbon","scotch","cognac","port-wine","popcorn","cotton-candy","pillow","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","soap","toothpaste","detergent","nitrile-glove","corn-flakes","fireworks","candle","salsa","fish-sticks","zip-bag","cotton-swab","mouthwash","cough-syrup","facial-tissue","envelope","power-outlet","champagne","toffee"],"steps":[{"name":"Blast and dig the pit","process":"mine","text":"Crews drill, blast and haul away the rock. Alongside the ore comes a lot of waste, both the bedrock above it and the unwanted minerals mixed into it. Rich hematite ore can be sold almost as it comes out of the ground.","inputs":[]},{"name":"Crush and screen","process":"crush","text":"Lower-grade ore is broken in stages, first coarse crushing and then fine grinding. Magnetite-bearing rock has to be milled to a very small particle size before the iron grains let go of the quartz around them.","inputs":[],"spec":"ground to 32 to 45 micrometers"},{"name":"Pull out the iron","process":"separate","text":"The powder is passed under magnetic separators, which lift the magnetite away and leave the quartz behind. Hematite is denser than the rock around it, so it is separated by sinking it in a heavy slurry or by froth flotation instead. The result is a fine powder called fines.","inputs":[]},{"name":"Dump the tailings","process":"separate","text":"What the magnets leave behind is mostly quartz, which is chemically inert. It is stored as a slurry in regulated settling ponds. Every ton of concentrate leaves between 2.5 and 3.0 tons of this waste.","inputs":[]}],"facts":["About 98% of mined iron ore is used to make steel.","Taconite is rolled into pellets about 10 millimeters across that are about 65% iron, then fired hard so they survive the trip to the furnace.","Taconite is the North American name for banded iron formation, a rock made of thin layers of iron oxide and silica."],"where":[{"place":"Australia","share":"largest producer"},{"place":"Brazil","share":"second, with 16% of world production"}],"whereNote":"Ranking and Brazil's 16% share as given in the Wikipedia iron ore article; Brazil produced 440 million tonnes in 2023.","sources":[{"title":"Iron ore","url":"https://en.wikipedia.org/wiki/Iron_ore"},{"title":"Taconite","url":"https://en.wikipedia.org/wiki/Taconite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"jam","name":"Jam","kind":"product","category":"food","title":"How jam is made","url":"https://assemblyline.org/make/jam","stations":6,"upstream":19,"downstream":0,"depth":7,"dek":"A factory can make jam at 65 to 80 °C, well below boiling, by cooking it under a vacuum.","answer":"Crushed fruit is cooked with about its own weight in sugar until pectin from the fruit links up and the mixture will set when cool. Factories boil in open pans or in a vacuum vessel, which lowers the boiling point and saves flavor. The jam is heated briefly for safety and filled hot into jars.","aka":["fruit preserves","preserves","fruit spread"],"inputs":["sugar","glass-jar"],"uses":[],"grounds":["sugarcane","sugar-beet","water","limestone","silica-sand","rock-salt","trona","natural-gas","air","corn"],"upstreamSlugs":["sugar","glass-jar","sugarcane","sugar-beet","water","lime","glass","limestone","silica-sand","soda-ash","rock-salt","ammonia","carbon-dioxide","trona","natural-gas","air","corn","yeast","molasses"],"downstreamSlugs":[],"steps":[{"name":"Crush the fruit","process":"crush","text":"Fruit is mashed or chopped into pulp. The fruit also supplies pectin, which is the gelling agent. Tart apples, currants and quinces carry plenty, while strawberries and peaches are low in it.","inputs":[]},{"name":"Cook with sugar","process":"cook","text":"The fruit is boiled with sugar and water. A common starting point is equal weights of fruit and sugar. Sugar both sweetens and preserves.","inputs":["sugar"]},{"name":"Top up the pectin","process":"mix","text":"For low-pectin fruit, makers add commercial pectin or high-pectin fruit, which also cuts cooking time. Pectin chains link into a network that holds the jam in a gel.","inputs":[]},{"name":"Boil down to the set point","process":"refine","text":"The batch cooks until the acid and pectin react with the sugar and it will set on cooling. In an open pan this happens at 104 °C. Under a vacuum the boiling point falls so far that water leaves the jam at a lower temperature, which keeps more fruit aroma and avoids burnt sugar.","inputs":[],"spec":"104 °C open pan; 65 to 80 °C under vacuum"},{"name":"Pasteurize briefly","process":"pasteurize","text":"A short heating kills pathogens that would otherwise grow.","inputs":[],"spec":"95 to 100 °C"},{"name":"Fill jars while hot","process":"fill","text":"A flame sterilizes the rim and lid of each jar, and steam is injected just before lidding. When that steam condenses, it makes a vacuum that pulls down the lid's safety button.","inputs":["glass-jar"]}],"facts":["Jam making became a great industry in 19th-century England, once sugar duties were repealed in 1874.","Marmalade is jam made with citrus peel, and Seville oranges are prized for it because they carry so much pectin."],"where":[],"whereNote":null,"sources":[{"title":"Jam","url":"https://en.wikipedia.org/wiki/Jam"},{"title":"Canning","url":"https://en.wikipedia.org/wiki/Canning"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"salsa","name":"Jarred salsa","kind":"product","category":"food","title":"How jarred salsa is made","url":"https://assemblyline.org/make/salsa","stations":9,"upstream":70,"downstream":0,"depth":10,"dek":"Factory salsa cooks either 45 minutes at 71 °C or just 30 seconds at 121 °C under pressure.","answer":"Tomatoes are inspected and peeled with lye, chilies are roasted or blanched, and machines dice the rest of the vegetables. A batch kettle cooks everything with vinegar and spices, either slowly at low heat or in seconds under pressure. Warm salsa is filled by volume into jars, sealed and cooled, and the shrinking contents pull a partial vacuum under the lid.","aka":["picante sauce","salsa roja","tomato salsa"],"inputs":["tomatoes","chili-pepper","onions","vinegar","water","table-salt","glass-jar","cardboard-box"],"uses":[],"grounds":["tomatoes","chili-pepper","onions","water","grapes","rock-salt","seawater","corn","sugarcane","barley","silica-sand","limestone","natural-gas","sugar-beet","trona","timber","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","coal"],"upstreamSlugs":["tomatoes","chili-pepper","onions","vinegar","water","table-salt","glass-jar","cardboard-box","grapes","ethanol","malted-barley","yeast","rock-salt","seawater","glass","cardboard","ink","adhesive","corn","sugarcane","ethylene","barley","molasses","silica-sand","soda-ash","limestone","wood-pulp","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","naphtha","natural-gas","sugar-beet","ammonia","carbon-dioxide","lime","trona","timber","caustic-soda","oxygen","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","propylene","methanol","acetone","nitric-acid","hydrogen","benzene","coal","toluene"],"downstreamSlugs":[],"steps":[{"name":"Peel the tomatoes","process":"wash","text":"Plants buy produce fresh, frozen or dehydrated. Tomatoes are inspected and peeled with lye, then stems, seeds and leftover skin come off.","inputs":["tomatoes"]},{"name":"Roast and blanch peppers","process":"cook","text":"Some makers roast green chilies before washing them. Stems, seeds and calyx are pulled, the peppers are blanched, and citric acid adjusts their pH.","inputs":["chili-pepper"]},{"name":"Wash and dice","process":"cut","text":"Onions, garlic and other vegetables pass through water tanks or high-pressure sprays, and machines remove skins and stems. Preset cutters dice them for a chunky jar or take them down to tomato consistency for a smooth one.","inputs":["onions"]},{"name":"Fill the premix kettle","process":"mix","text":"Tomato paste or processed tomatoes, water, vinegar, salt and spices go into a kettle big enough for several batches. Acid sets the rest of the process, since food below pH 4.6 can be safely processed at boiling temperature.","inputs":["vinegar","water","table-salt"],"spec":"pH below 4.6"},{"name":"Cook in the batch kettle","process":"cook","text":"Premix joins the onions and chilies in a batch kettle. The slow method holds 71 °C for 45 minutes, and the fast one hits 121 °C under pressure for 30 seconds.","inputs":[],"spec":"71 °C for 45 minutes or 121 °C for 30 seconds"},{"name":"Fill by volume","process":"fill","text":"A filler measures still-warm salsa by volume into glass jars or heat-resistant plastic. Fresh salsa takes the reverse order, going in cold and getting steam heated in the container.","inputs":["glass-jar"]},{"name":"Seal and cool","process":"chill","text":"Lids go on, and cold water or air cools the jars. The hot salsa contracts as it cools and draws a partial vacuum under each seal.","inputs":[]},{"name":"Taste and swab","process":"inspect","text":"Experienced tasters check flavor and heat against the label. Kettles are swabbed and the swabs incubated for a day or two, and samples of finished salsa get the same lab treatment.","inputs":[]},{"name":"Label and box","process":"package","text":"Containers without preprinted information get labels, then go into corrugated cartons for shipping.","inputs":["cardboard-box"]}],"facts":["By 1992, the dollar value of salsa sold in the United States was higher than the value of tomato ketchup.","The word salsa simply means sauce in Spanish, but in English it refers to Mexican table sauces.","Tortilla chips with salsa are a routine starter at Mexican-American restaurants, yet not south of the border."],"where":[],"whereNote":null,"sources":[{"title":"Salsa, How Products Are Made (Gale), Encyclopedia.com","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/salsa"},{"title":"Salsa (food)","url":"https://en.wikipedia.org/wiki/Salsa_(food)"},{"title":"Canning","url":"https://en.wikipedia.org/wiki/Canning"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"jeans","name":"Jeans","kind":"product","category":"textiles","title":"How jeans are made","url":"https://assemblyline.org/make/jeans","stations":7,"upstream":51,"downstream":0,"depth":9,"dek":"The copper rivets on jeans were added in 1871 to stop miners' pockets from ripping.","answer":"Jeans start as bolts of indigo denim, cut into stacked panels by the dozen. Workers sew pockets and long seams, punch copper rivets into stress points, fit the zipper and button, then hem the legs. Most pairs are washed afterward to soften the cloth and cut shrinkage, then pressed and packed.","aka":["blue jeans","denim trousers","dungarees"],"inputs":["denim","thread","zipper","copper","button","water"],"uses":[],"grounds":["water","indigo-plant","copper-ore","air","raw-cotton","crude-oil","coal","sulfur","natural-gas","zinc-ore","lead-ore","tin-ore","bauxite","rock-salt","limestone","corn","sugarcane","sugar-beet"],"upstreamSlugs":["denim","thread","zipper","copper","button","water","cotton-yarn","indigo-plant","polyester","nylon","brass","aluminum","copper-ore","oxygen","air","sulfuric-acid","raw-cotton","pet-plastic","benzene","nitric-acid","ammonia","zinc","lead","tin","crude-oil","coal","petroleum-coke","alumina","sulfur","p-xylene","ethylene","ethylene-glycol","naphtha","hydrogen","toluene","natural-gas","zinc-ore","lead-ore","coke","tin-ore","bauxite","caustic-soda","lime","carbon-dioxide","rock-salt","limestone","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Stack and cut the panels","process":"cut","text":"Bolts of denim are spread in many layers on a long table. A cutter follows a marked pattern to slice out the legs, pockets and waistbands of dozens of pairs at once.","inputs":["denim"]},{"name":"Stitch pockets and seams","process":"sew","text":"Sewers attach the pockets to the front and back panels, then run the long inner and outer seams. Jeans have had the same five-pocket layout since a rear pocket was added in 1901.","inputs":["thread"]},{"name":"Set the zipper","process":"assemble","text":"The fly gets a zipper before the long seams are closed. By the 1960s, jeans for men and women had a zipper down the front.","inputs":["zipper","thread"]},{"name":"Hem the legs","process":"sew","text":"The legs are folded, hemmed and finished with a final row of stitching. The waistband is closed over the zipper tape, and loops are added for a belt.","inputs":["thread"]},{"name":"Punch in rivets and button","process":"assemble","text":"Copper rivets are pressed through the corners of the pockets, where the cloth gets the most strain, and the waistband button is set. Jacob Davis added rivets to work trousers in 1871.","inputs":["copper","button"]},{"name":"Wash them softer","process":"wash","text":"Many denim garments are washed after sewing, which makes them softer and cuts shrinkage beyond what the cloth treatment already prevents. A worn look comes from abrading the cloth or treating it with chemicals.","inputs":["water"]},{"name":"Press and pack","process":"package","text":"The finished pairs are pressed, tagged and folded for shipping.","inputs":[]}],"facts":["Davis and Levi Strauss received a patent for rivet-reinforced trousers on May 20, 1873.","A typical pair of blue jeans uses 3,479 liters of water over its life, counting the cotton crop, the factory and the washes at home.","Levi's introduced its own pre-shrunk jeans in 1962, and Lee and Wrangler had long done it already."],"where":[],"whereNote":null,"sources":[{"title":"Jeans","url":"https://en.wikipedia.org/wiki/Jeans"},{"title":"Denim","url":"https://en.wikipedia.org/wiki/Denim"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"jelly-beans","name":"Jelly beans","kind":"product","category":"food","title":"How jelly beans are made","url":"https://assemblyline.org/make/jelly-beans","stations":6,"upstream":12,"downstream":0,"depth":3,"dek":"A jelly bean starts as a soft gel center cast in cornstarch, then gets a hard shell built up in a spinning drum.","answer":"Jelly beans have two parts. A soft center of sugar, corn syrup and pectin or starch is cooked and poured into bean-shaped dents in trays of cornstarch to set. The centers are then tumbled in a spinning drum while layers of sugar syrup build a thin candy shell, and a final coat of edible wax gives the shine.","aka":["jellybeans","jelly bean candy"],"inputs":["sugar","corn-syrup","corn-starch","water","carnauba","beeswax"],"uses":[],"grounds":["water","carnauba","sugarcane","sugar-beet","corn","honeycomb","limestone"],"upstreamSlugs":["sugar","corn-syrup","corn-starch","water","carnauba","beeswax","sugarcane","sugar-beet","lime","corn","honeycomb","limestone"],"downstreamSlugs":[],"steps":[{"name":"Cook the gel centers","process":"cook","text":"Sugar, corn syrup and a gelling agent such as pectin or starch are boiled together. Tapioca can be included in the mix. Flavor and color are added at the end, and each flavor has its own small adjustments.","inputs":["sugar","corn-syrup","corn-starch","water"]},{"name":"Cast beans in starch","process":"mold","text":"In a starch mogul, bean-shaped dents are stamped into trays of dry starch and filled with the liquid. Starch pulls moisture from the surface while the gel sets.","inputs":[]},{"name":"Let the centers cure","process":"dry","text":"Trays rest in a warm room until the centers are firm enough to roll around without losing their shape. Extra starch is then shaken and brushed away.","inputs":[]},{"name":"Tumble on sugar syrup","process":"coat","text":"The centers go into a large rotating pan. Workers or machines drizzle in sugar syrup, which dries onto the beans in thin layers until a soft candy shell builds up.","inputs":["sugar"]},{"name":"Buff with edible wax","process":"coat","text":"Alternating coats of confectioner's glaze and carnauba wax, with beeswax sometimes used too, go into the pan with the finished beans. Tumbling spreads each into a thin layer that makes the shell glossy and keeps the beans from sticking together.","inputs":["carnauba","beeswax"]},{"name":"Sort and pack","process":"package","text":"Beans are inspected for dents and blobs, weighed by flavor and bagged. Some factories blend dozens of flavors into a single bag.","inputs":[]}],"facts":["A Jelly Belly bean takes a week or more to make, because the candies rest three times along the way.","The shell-building in the spinning drums makes each candy about 40 percent bigger.","In 1910s American slang, a jellybean was a stylish young man with little else to recommend him."],"where":[],"whereNote":null,"sources":[{"title":"Jelly bean","url":"https://en.wikipedia.org/wiki/Jelly_bean"},{"title":"Starch mogul","url":"https://en.wikipedia.org/wiki/Starch_mogul"},{"title":"Dragée","url":"https://en.wikipedia.org/wiki/Dragée"},{"title":"Gummy candy","url":"https://en.wikipedia.org/wiki/Gummy_candy"},{"title":"Jelly bean: how products are made","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/jelly-bean"},{"title":"Inside the factory where Jelly Belly makes its beans","url":"https://www.popsci.com/technology/jelly-belly-bean-factory-photos/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"jet-engine","name":"Jet engine","kind":"product","category":"machines","title":"How jet engines are made","url":"https://assemblyline.org/make/jet-engine","stations":7,"upstream":49,"downstream":1,"depth":7,"dek":"The turbine blades in a jet engine run in gas hotter than the metal they are made of would normally survive.","answer":"A jet engine sucks in air, squeezes it with a bank of spinning compressor blades, burns fuel in it and passes the hot gas through a turbine that drives the compressor. Its parts are forged titanium and cast nickel superalloy, machined to tight limits, balanced, assembled in modules and run on a test stand.","aka":["gas turbine","turbofan","turbojet"],"inputs":["titanium","nickel","turbine-blade","jet-fuel"],"uses":["airplane"],"grounds":["titanium-ore","nickel-ore","crude-oil","rock-salt","water","dolomite","air","sulfur","clay","kaolin","feldspar","quartz","cobalt-ore","chromite","limestone","natural-gas","coal","timber","trona","bauxite","corn","sugarcane","sugar-beet"],"upstreamSlugs":["titanium","nickel","turbine-blade","jet-fuel","titanium-ore","chlorine","magnesium","argon","nickel-ore","sulfuric-acid","paraffin-wax","ceramic","cobalt","chromium","crude-oil","hydrogen","rock-salt","water","dolomite","silicon","air","sulfur","clay","kaolin","feldspar","quartz","cobalt-ore","aluminum","chromite","coke","soda-ash","limestone","natural-gas","coal","charcoal","timber","petroleum-coke","alumina","ammonia","carbon-dioxide","lime","trona","bauxite","caustic-soda","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["airplane"],"steps":[{"name":"Forge the fan and compressor blades","process":"forge","text":"Titanium is pressed hot into blade shapes that must withstand centrifugal pull and the impact of air at speed. The blades are then machined and polished.","inputs":["titanium"]},{"name":"Forge the heavy disks","process":"forge","text":"The disks that hold the blades are forged from nickel-based alloys and titanium, then heat-treated and machined. They spin faster and hotter than almost anything else in a machine.","inputs":["nickel","titanium"]},{"name":"Fit the cast turbine blades","process":"assemble","text":"Turbine blades come from a specialist foundry, where they are cast from superalloy around ceramic cores and coated against heat. They sit directly behind the combustor.","inputs":["turbine-blade"]},{"name":"Weld the combustor and casings","process":"weld","text":"Sheets of nickel alloy are formed and welded into the burner liner and outer casings, with a ring of fine holes that let cool air in.","inputs":["nickel"]},{"name":"Balance the rotor","process":"grind","text":"The shaft and disks are stacked up and spun on a balancing machine. Material is ground off wherever a heavy spot shows up.","inputs":[]},{"name":"Build it up in modules","process":"assemble","text":"Fan, compressor, combustor and turbine are each put together as a module. Modules are then joined, and the fuel, oil and control systems are piped on.","inputs":[]},{"name":"Run it on a test stand","process":"inspect","text":"The engine is run through its full power range, and thrust, temperatures and vibration are logged before it is cleared for an airplane.","inputs":["jet-fuel"]}],"facts":["The GE90 turbofan of the 1990s produced 115,000 pounds of thrust, against 5,000 for a 1950s turbojet.","In-flight shutdowns fell from 40 per 100,000 engine flight hours to under 1 per 100,000 by the late 1990s.","A Heinkel He 178 with a gasoline-fuelled HeS 3 engine flew on August 27, 1939."],"where":[],"whereNote":null,"sources":[{"title":"Jet engine","url":"https://en.wikipedia.org/wiki/Jet_engine"},{"title":"Turbine blade","url":"https://en.wikipedia.org/wiki/Turbine_blade"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"jet-fuel","name":"Jet fuel","kind":"product","category":"chemicals","title":"How jet fuel is made","url":"https://assemblyline.org/make/jet-fuel","stations":6,"upstream":4,"downstream":2,"depth":2,"dek":"Jet fuel is kerosene, held to an international specification so tight that it must stay liquid at altitude.","answer":"Jet fuel is made from the kerosene cut of crude oil. The cut is drawn from the middle of a distillation tower, treated with hydrogen to remove sulfur and other contaminants, and filtered. Additives are blended in, and each batch is tested against a standard that sets its freezing point and smoke point.","aka":["aviation turbine fuel","Jet A-1","kerosene","avtur"],"inputs":["crude-oil","hydrogen"],"uses":["airplane","jet-engine"],"grounds":["crude-oil","natural-gas","water"],"upstreamSlugs":["crude-oil","hydrogen","natural-gas","water"],"downstreamSlugs":["airplane","jet-engine"],"steps":[{"name":"Heat and boil the crude","process":"refine","text":"Desalted crude oil is heated and fed into the atmospheric distillation tower. The kerosene cut condenses on a tray above the diesel and below the naphtha.","inputs":["crude-oil"]},{"name":"Treat it with hydrogen","process":"react","text":"The kerosene is reacted with hydrogen over a catalyst to remove sulfur and other contaminants. Some refineries use a milder chemical wash instead.","inputs":["hydrogen"]},{"name":"Filter out water and grit","process":"separate","text":"Clay filters and water separators strip out the last traces of water, dirt and polar compounds. Water would freeze into ice crystals at cruising altitude.","inputs":[]},{"name":"Blend in the additives","process":"mix","text":"Additives are dosed into the fuel to prevent static buildup, corrosion and oxidation.","inputs":[]},{"name":"Test every batch","process":"inspect","text":"Samples are tested for freezing point, smoke point, flash point and more against the specification. A batch that fails is blended or reprocessed.","inputs":[]},{"name":"Pipe it to the airport","process":"fill","text":"Pipelines, trains and tanker trucks carry the fuel to airport depots. It is filtered again before it goes into the aircraft.","inputs":[]}],"facts":["The main difference between Jet A and Jet A-1, the two fuels most airlines use, is that Jet A-1 has the lower freezing point.","Kerosene-type jet fuel molecules have about 8 to 16 carbon atoms, while wide-cut fuel such as Jet B has about 5 to 15."],"where":[],"whereNote":null,"sources":[{"title":"Jet fuel","url":"https://en.wikipedia.org/wiki/Jet_fuel"},{"title":"Kerosene","url":"https://en.wikipedia.org/wiki/Kerosene"},{"title":"Oil refinery","url":"https://en.wikipedia.org/wiki/Oil_refinery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"jigsaw-puzzle","name":"Jigsaw puzzle","kind":"product","category":"play","title":"How jigsaw puzzles are made","url":"https://assemblyline.org/make/jigsaw-puzzle","stations":7,"upstream":58,"downstream":0,"depth":10,"dek":"A puzzle is cut in one stroke, as a hydraulic press drives a hand-built steel cutter through printed board.","answer":"Most modern jigsaw puzzles are paperboard. The picture is offset-printed on paper, glued to thick cardboard and coated for protection. A hydraulic press then drives a die, a set of steel blades bent into the piece pattern, through the board so every piece is cut at once. Pieces are inspected, bagged and boxed.","aka":["jigsaw","puzzle","dissected puzzle"],"inputs":["ink","paper","cardboard","adhesive","plastic","cardboard-box"],"uses":[],"grounds":["water","kaolin","limestone","natural-gas","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","timber","rock-salt","coal","sugar-beet"],"upstreamSlugs":["ink","paper","cardboard","adhesive","plastic","cardboard-box","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","wood-pulp","kaolin","limestone","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","naphtha","natural-gas","ethylene","propylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","timber","caustic-soda","lime","hydrogen-peroxide","ammonia","methanol","acetone","nitric-acid","hydrogen","benzene","rock-salt","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Offset-print the picture","process":"print","text":"The image runs through an offset press onto high-quality paper.","inputs":["ink","paper"]},{"name":"Glue it to board","process":"laminate","text":"A water-based adhesive bonds the printed sheet to a thick cardboard backing, which is cheaper and easier to mass-produce than the wood used for puzzles in the 18th century.","inputs":["cardboard","adhesive"]},{"name":"Coat the image","process":"coat","text":"A UV coating or laminate protects the picture from wear and gives it a gloss.","inputs":[]},{"name":"Build the steel cutter","process":"machine","text":"At Ravensburger each piece is first sketched by hand on paper draped over the image, so that no two share a shape. Metal is then bent into that pattern, which takes about four weeks.","inputs":[],"spec":"about four weeks per cutter"},{"name":"Press every piece out","process":"stamp","text":"A hydraulic press forces the die through the board. The pressure has to be controlled closely so the cuts stay clean without crushing the cardboard.","inputs":[]},{"name":"Inspect the cut pieces","process":"inspect","text":"Pieces that are badly cut or flawed are thrown out.","inputs":[]},{"name":"Bag and box","process":"package","text":"The loose pieces go into a plastic bag, which goes into the printed box.","inputs":["plastic","cardboard-box"]}],"facts":["The first commercial jigsaw puzzle was a map cut along national borders around 1760, made to teach geography.","Ravensburger can resharpen a dulled cutter only once before scrapping it.","A 1,000-piece Ravensburger puzzle has 1,000 different shapes, so that no piece can fit in the wrong place by accident."],"where":[],"whereNote":null,"sources":[{"title":"How Are Puzzles Made?","url":"https://www.galison.com/blogs/articles/how-are-puzzles-made"},{"title":"Here's How Those Hot Jigsaw Puzzles Are Made","url":"https://www.bespacific.com/?p=75138"},{"title":"Jigsaw puzzle","url":"https://en.wikipedia.org/wiki/Jigsaw_puzzle"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"juniper-berries","name":"Juniper berries","kind":"raw","category":"farm","title":"Where juniper berries come from","url":"https://assemblyline.org/make/juniper-berries","stations":3,"upstream":0,"downstream":1,"depth":0,"dek":"A juniper berry is really a conifer cone whose scales fused into something fleshy.","answer":"Juniper berries are the female seed cones of juniper shrubs, with scales that stay fleshy and merge into one purple-black skin. They ripen slowly, over about 18 months for the common juniper. Pickers gather them and sell them fresh or dried. They are crushed to release a piney, resinous flavor.","aka":["juniper berry","juniper cones","galbulus"],"inputs":[],"uses":["gin"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["gin"],"steps":[{"name":"Let the cones ripen slowly","process":"grow","text":"The cone starts green and takes about 18 months to turn purple-black on the common juniper. A single bush carries cones of several ages at once.","inputs":[],"spec":"about 18 months to ripen"},{"name":"Strip the ripe cones","process":"harvest","text":"Gatherers take the mature dark cones for cooking. Gin makers want fully grown but still unripe ones, so the same bush supplies two different crops.","inputs":[]},{"name":"Dry and crush for flavor","process":"dry","text":"Berries are sold fresh or dried, but their scent is strongest right after picking and fades in storage. Cooks crush them lightly, because the outer scales have almost no flavor.","inputs":[]}],"facts":["The word gin comes from the French genièvre or the Dutch jenever, both meaning juniper.","Romans used juniper berries as a cheap stand-in for imported black pepper.","Juniper berries are among the few spices that come from conifers."],"where":[],"whereNote":null,"sources":[{"title":"Juniper berry","url":"https://en.wikipedia.org/wiki/Juniper_berry"},{"title":"Juniperus communis","url":"https://en.wikipedia.org/wiki/Juniperus_communis"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"kaolin","name":"Kaolin","kind":"raw","category":"ground","title":"How kaolin is mined","url":"https://assemblyline.org/make/kaolin","stations":3,"upstream":0,"downstream":41,"depth":0,"dek":"Kaolin is named after a Chinese hill, and the English word traces to a 1712 report on making porcelain.","answer":"Kaolin, also called china clay, is a soft, white clay rock made mainly of the mineral kaolinite, which forms when feldspar weathers. Miners dig it from open pits, then slurry and refine it into a bright white product. It is shipped as powder, lumps, semi-dried noodles or slurry for paper and porcelain.","aka":["china clay"],"inputs":[],"uses":["ceramic","porcelain","toilet","eyeshadow","paper"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["ceramic","porcelain","toilet","eyeshadow","paper","hip-implant","faucet","turbine-blade","snow-globe","soap","adhesive-bandage","aa-battery","vacuum-cleaner","drywall","popcorn","crayon","fireworks","plastic-straw","paper-straw","paper-cup","paper-bag","pizza-box","egg-carton","wallpaper","laminate-floor","board-game","jigsaw-puzzle","tampon","sanitary-pad","cotton-swab","loudspeaker","vinyl-record","compact-disc","inkjet-printer","newspaper","book","envelope","sticky-notes","playing-cards","jet-engine","airplane"],"steps":[{"name":"Strip the white clay","process":"mine","text":"Kaolin lies in thick beds formed by the chemical weathering of aluminum silicate minerals such as feldspar. Open pits remove the overlying soil and cut into the clay.","inputs":[]},{"name":"Slurry and screen","process":"wash","text":"The clay is mixed with water into a slurry and screened to remove sand and rock. Iron oxide can tint it pink, orange or red, so purity is judged by how white it is.","inputs":[]},{"name":"Dry and ship","process":"dry","text":"After dewatering, kaolin ships as powder, lumps, semi-dried noodle or slurry, depending on what the customer will do with it.","inputs":[]}],"facts":["The English word kaolin was borrowed in 1727 from a 1712 French report on how Jingdezhen made porcelain.","The Chinese name gaoling means high ridge and comes from a village near Jingdezhen.","Sandersville, Georgia, calls itself the Kaolin Capital of the World."],"where":[],"whereNote":null,"sources":[{"title":"Kaolinite","url":"https://en.wikipedia.org/wiki/Kaolinite"},{"title":"Clay","url":"https://en.wikipedia.org/wiki/Clay"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ketchup","name":"Ketchup","kind":"product","category":"food","title":"How ketchup is made","url":"https://assemblyline.org/make/ketchup","stations":8,"upstream":36,"downstream":0,"depth":7,"dek":"Ketchup is tomato puree boiled down thick with vinegar and sugar, and it does not run until you shake it.","answer":"Water carries tomatoes from the truck into the plant, where they are washed, sorted, chopped and pre-cooked, then pulped to strip out seeds and skins. The pulp boils for 30 to 45 minutes with salt, herbs, sugar and vinegar. It is filtered, deaerated, heated to at least 88 °C, filled into bottles, capped and cooled at once.","aka":["catsup","tomato ketchup","tomato sauce"],"inputs":["tomatoes","water","table-salt","sugar","vinegar","glass-bottle","plastic-bottle"],"uses":[],"grounds":["tomatoes","water","rock-salt","seawater","sugarcane","sugar-beet","grapes","silica-sand","limestone","corn","barley","trona","natural-gas","air","crude-oil"],"upstreamSlugs":["tomatoes","water","table-salt","sugar","vinegar","glass-bottle","plastic-bottle","rock-salt","seawater","sugarcane","sugar-beet","lime","grapes","ethanol","malted-barley","yeast","silica-sand","soda-ash","limestone","polyethylene","pet-plastic","corn","ethylene","barley","molasses","ammonia","carbon-dioxide","trona","p-xylene","ethylene-glycol","naphtha","natural-gas","air","oxygen","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Flume and wash the tomatoes","process":"wash","text":"A stream of water floats the tomatoes off the trucks, which avoids bruising and gives them a first rinse. After a short wait they tumble through rotating drums for a second wash, and the water drains away.","inputs":["tomatoes","water"]},{"name":"Sort, chop and pre-cook","process":"cook","text":"A sorting machine picks out fruit of consistent quality. The tomatoes are then reduced and pre-cooked in stainless steel vessels, which preserves them and kills microorganisms.","inputs":[]},{"name":"Pulp out seeds and skins","process":"separate","text":"A cyclone turns the hot fruit into pulp and throws off seeds, skins and stems. The pulp and juice are filtered before moving on. Some plants skip these steps and start from bought-in tomato puree, with a shorter boil.","inputs":[]},{"name":"Boil with the seasoning","process":"cook","text":"The pulp boils in a combined mixing and cooking kettle until it reaches the right concentration. Salt and herbs go in at the start. Sugar may come later to prevent burning, and vinegar arrives at the end with any volatile herbs so their aroma survives.","inputs":["table-salt","sugar","vinegar"],"spec":"30 to 45 minutes"},{"name":"Filter and homogenize","process":"separate","text":"A final filtration removes remaining fibers and particles. Some makers then homogenize the sauce, which raises its viscosity.","inputs":[]},{"name":"Pull out the air","process":"separate","text":"Filtering beats air into the sauce, which would feed bacteria, form bubbles and discolor it. A vent removes the air, or the sauce is held at 90 °C for a set time.","inputs":[]},{"name":"Fill hot and cap","process":"fill","text":"The sauce is heated to at least 88 °C so nothing can contaminate it during filling, then goes into glass or plastic bottles. Narrow necks limit its contact with air, and caps go on immediately.","inputs":["glass-bottle","plastic-bottle"],"spec":"at least 88 °C"},{"name":"Cool the bottles fast","process":"chill","text":"Cold air or cold water brings the filled bottles down straight away, since long storage at high temperature costs flavor. They are labeled and checked, and boxes are often stored upside down to prevent browning in the neck.","inputs":[]}],"facts":["The word ketchup first appeared in print in 1682, long before tomatoes were in the recipe.","Early ketchups were made from mushrooms, oysters, mussels, egg whites, grapes or walnuts."],"where":[],"whereNote":null,"sources":[{"title":"Safe Food Factory: Tomato ketchup","url":"https://www.safefoodfactory.com/en/knowledge/75-tomatenketchup-en/"},{"title":"Ketchup","url":"https://en.wikipedia.org/wiki/Ketchup"},{"title":"Vinegar","url":"https://en.wikipedia.org/wiki/Vinegar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"kevlar","name":"Kevlar","kind":"material","category":"plastics","title":"How Kevlar is made","url":"https://assemblyline.org/make/kevlar","stations":6,"upstream":12,"downstream":2,"depth":4,"dek":"Stephanie Kwolek's cloudy, runny liquid was nearly thrown away, and it turned into a fiber that did not break.","answer":"Kevlar is made by joining two petrochemicals, para-phenylenediamine and terephthaloyl chloride, into a rigid polymer. The polymer is dissolved in concentrated sulfuric acid, which keeps it liquid. The solution is spun through fine holes into cold water, and the fibers are washed, dried and stretched.","aka":["para-aramid","aramid fiber"],"inputs":["p-xylene","ammonia","chlorine","sulfuric-acid"],"uses":["brake-pad","canoe"],"grounds":["natural-gas","water","air","rock-salt","sulfur","crude-oil"],"upstreamSlugs":["p-xylene","ammonia","chlorine","sulfuric-acid","naphtha","natural-gas","water","air","rock-salt","sulfur","crude-oil","hydrogen"],"downstreamSlugs":["brake-pad","canoe"],"steps":[{"name":"Make the two building blocks","process":"react","text":"One monomer is a diamine built from refinery aromatics and ammonia. Its partner is a chlorinated form of terephthalic acid, which is made from p-xylene and chlorine.","inputs":["p-xylene","ammonia","chlorine"]},{"name":"Join them in solution","process":"react","text":"In a solvent, the two react in a condensation reaction that yields hydrochloric acid as a byproduct. Long, stiff polymer chains settle out as a yellow powder.","inputs":[]},{"name":"Dissolve it in strong acid","process":"mix","text":"The water-insoluble polymer is dissolved in concentrated sulfuric acid. This is difficult to handle, which is a reason Kevlar costs so much to make.","inputs":["sulfuric-acid"]},{"name":"Spin it into a cold bath","process":"spin","text":"The thick liquid is pushed through a spinneret and drops into cold water, where the polymer solidifies. The stiff chains line up along the thread as they come out.","inputs":[]},{"name":"Wash out the acid","process":"wash","text":"Water rinses the sulfuric acid from the new fiber, and the acid is neutralized or reclaimed. The fiber is then dried on heated rolls.","inputs":[]},{"name":"Wind it onto spools","process":"package","text":"The yarn is wound onto bobbins for weavers. It is cut into short lengths or woven into cloth for armor, tires and ropes.","inputs":[]}],"facts":["Stephanie Kwolek developed Kevlar at DuPont in 1965, and its first commercial use in the early 1970s was in racing tires as a replacement for steel.","Her polymer solution was cloudy and runny and was usually thrown away, until she persuaded technician Charles Smullen to try spinning it.","By tensile strength for its weight, Kevlar is five times stronger than steel."],"where":[],"whereNote":null,"sources":[{"title":"Kevlar","url":"https://en.wikipedia.org/wiki/Kevlar"},{"title":"Nylon","url":"https://en.wikipedia.org/wiki/Nylon"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"key","name":"Key","kind":"product","category":"hardware","title":"How keys are made","url":"https://assemblyline.org/make/key","stations":6,"upstream":27,"downstream":0,"depth":5,"dek":"Linus Yale Sr. invented the modern pin tumbler lock in 1848, and a key is just its cheap, shaped partner.","answer":"A house key usually starts as a blank punched from flat sheet brass or nickel silver in a heavy press. Long grooves milled down the blade fit it to one style of keyway, and it can then be plated. Blanks ship uncut. A key machine traces an original with a guide while a spinning wheel copies its notches into the blank.","aka":["door key","house key"],"inputs":["brass","nickel"],"uses":[],"grounds":["nickel-ore","copper-ore","water","air","zinc-ore","lead-ore","tin-ore","crude-oil","coal","sulfur","bauxite","rock-salt","limestone"],"upstreamSlugs":["brass","nickel","copper","zinc","lead","tin","aluminum","nickel-ore","sulfuric-acid","copper-ore","water","oxygen","air","zinc-ore","lead-ore","coke","tin-ore","crude-oil","coal","petroleum-coke","alumina","sulfur","bauxite","caustic-soda","lime","rock-salt","limestone"],"downstreamSlugs":[],"steps":[{"name":"Punch the blank","process":"stamp","text":"A heavy press punches key shapes from flat sheet metal, usually brass or nickel silver because they are soft enough to work and to cut later. Some factories die-cast a rough shape instead.","inputs":["brass"]},{"name":"Size the blade","process":"machine","text":"Edges are sheared clean, and each blank is milled to the correct thickness and trimmed to length.","inputs":[]},{"name":"Mill the grooves","process":"machine","text":"Cutters or a stamping die run lengthwise down the blade, forming the slots that match the shape of the keyhole. The cross-section is what ties a blank to a particular brand or style of lock.","inputs":[]},{"name":"Plate it","process":"coat","text":"A 1942 patent sends its stamped blank straight to plating once the slots are in. Finished keys commonly come as plated brass or nickel silver, and the blanks then ship uncut to locksmiths and hardware stores.","inputs":["nickel"]},{"name":"Clamp beside the original","process":"assemble","text":"A duplicating machine holds the original and a matching blank side by side in separate clamps. Both are lined up by the same reference edge.","inputs":[]},{"name":"Trace the notches","process":"machine","text":"A tracer rides along the peaks and valleys of the original while a linked cutter wheel carves the same pattern into the blank. Each notch has to match the lock it was made for.","inputs":[]}],"facts":["Archaeologists found the oldest known lock at Nineveh in ancient Assyria, and people have used locks for more than 6000 years.","Robert Barron invented the lever tumbler lock in 1778.","American Linus Yale Sr. invented the modern pin tumbler lock in 1848."],"where":[],"whereNote":null,"sources":[{"title":"US2301531A, Key blank and method of making the same","url":"https://patents.google.com/patent/US2301531"},{"title":"US5167171A, Universal key blank and key duplication method","url":"https://patents.google.com/patent/US5167171"},{"title":"How Are Keys Made? From Blanks to Duplicates, Climb the Ladder","url":"https://climbtheladder.com/how-are-keys-made-from-blanks-to-duplicates/"},{"title":"Key (lock)","url":"https://en.wikipedia.org/wiki/Key_(lock)"},{"title":"Brass","url":"https://en.wikipedia.org/wiki/Brass"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"kimchi","name":"Kimchi","kind":"product","category":"food","title":"How kimchi is made","url":"https://assemblyline.org/make/kimchi","stations":6,"upstream":11,"downstream":0,"depth":3,"dek":"Kimchi ferments so energetically that the jar builds up carbon dioxide and has to be burped.","answer":"Napa cabbage or radish is cut up and salted to draw out water, then drained and coated with a paste of chili powder, garlic, ginger, scallions and salted seafood. Packed into airtight containers, the mixture ferments for a day or two at room temperature, then keeps ripening more slowly in the cold.","aka":["gimchi","fermented napa cabbage"],"inputs":["cabbage","table-salt","sugar","chili-pepper"],"uses":[],"grounds":["cabbage","chili-pepper","rock-salt","seawater","sugarcane","sugar-beet","water","limestone"],"upstreamSlugs":["cabbage","table-salt","sugar","chili-pepper","rock-salt","seawater","sugarcane","sugar-beet","water","lime","limestone"],"downstreamSlugs":[],"steps":[{"name":"Cut the vegetables","process":"cut","text":"Napa cabbage or Korean radish is sliced or quartered into uniform pieces. More cut surface means salt and seasoning reach everywhere.","inputs":["cabbage"]},{"name":"Salt it down","process":"mix","text":"Coarse brining salt coats the pieces, pulls out water and stops harmful microbes. Cabbage may be salted twice.","inputs":["table-salt"],"spec":"5 to 7% salt for 12 hours"},{"name":"Drain off the water","process":"separate","text":"The excess water is drained away. The vegetables are limp, salty and ready to take up seasoning.","inputs":[]},{"name":"Rub in the seasoning","process":"mix","text":"A paste of gochugaru chili powder, scallions, garlic, ginger and salted seafood or fish sauce is worked through the vegetables, with sugar to bind remaining water. The chili powder and salt help the good bacteria outcompete the harmful ones.","inputs":["sugar","chili-pepper"]},{"name":"Pack airtight to ferment","process":"ferment","text":"The seasoned vegetables go into airtight jars or containers and ferment at room temperature. Gas builds as bacteria work, so the container needs to be vented.","inputs":[],"spec":"24 to 48 hours, about 3% salt"},{"name":"Ripen in the cold","process":"chill","text":"Cold slows the bacteria to a crawl, and the kimchi continues to sour gradually. Leuconostoc dominates early. As acid rises, Lactobacillus and Weissella take over.","inputs":[]}],"facts":["Napa cabbage only arrived in Korea at the end of the 19th century, so earlier kimchi was mostly made with radish.","In 2008 South Korean scientists made a sterile, bacteria-free space kimchi for the first Korean astronaut, since cosmic rays might mutate live cultures."],"where":[],"whereNote":null,"sources":[{"title":"Kimchi","url":"https://en.wikipedia.org/wiki/Kimchi"},{"title":"Pickling","url":"https://en.wikipedia.org/wiki/Pickling"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"kitchen-knife","name":"Kitchen knife","kind":"product","category":"hardware","title":"How kitchen knives are made","url":"https://assemblyline.org/make/kitchen-knife","stations":6,"upstream":36,"downstream":0,"depth":7,"dek":"A cheap kitchen knife is cut from a rolled steel sheet like a cookie from dough, then hardened.","answer":"Most kitchen knife blades are either stamped or forged. Stamped blades are cut from a sheet of cold-rolled steel, heat-treated for strength, then ground, polished and sharpened. Forged blades are hammered hot, quenched and tempered. A handle is fixed on at the end.","aka":["chef's knife","cook's knife"],"inputs":["stainless-steel","lumber"],"uses":[],"grounds":["timber","chromite","limestone","air","water","nickel-ore","natural-gas","crude-oil","coal","rock-salt","trona","sulfur","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["stainless-steel","lumber","steel-scrap","chromium","nickel","oxygen","argon","timber","propane","chromite","coke","soda-ash","limestone","air","water","aluminum","nickel-ore","sulfuric-acid","natural-gas","crude-oil","coal","rock-salt","ammonia","carbon-dioxide","lime","trona","petroleum-coke","alumina","sulfur","corn","yeast","bauxite","caustic-soda","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Stamp out the blade shape","process":"stamp","text":"A press cuts blade-shaped blanks from a sheet of cold-rolled steel. Stamped blades often lack the thick collar called a bolster, which is one way to tell them from forged ones.","inputs":["stainless-steel"]},{"name":"Harden in the furnace","process":"heat-treat","text":"Blanks go through a furnace and a quench so the steel turns hard enough to hold an edge, then a gentler reheat takes away the brittleness.","inputs":[]},{"name":"Grind the bevels","process":"grind","text":"Abrasive belts take the flat blank down toward its edge. The cross-section can be a straight wedge or a hollow curve, which decides how food slides off.","inputs":[]},{"name":"Polish the flats","process":"grind","text":"The sides are buffed smooth so the blade looks even and resists sticking and staining.","inputs":[]},{"name":"Fit the handle","process":"assemble","text":"Scales of wood or plastic are riveted to the tang, or a handle is molded on, and the blade is checked for balance.","inputs":["lumber"]},{"name":"Hone the edge","process":"grind","text":"Fine wheels or stones give the final edge before the knife is cleaned and packed.","inputs":[]}],"facts":["Carbon-steel kitchen knives hold an edge well and contain about 1 percent carbon.","Stainless knife steel is roughly 10 to 15 percent chromium, which resists rust.","Ceramic knife blades are made from sintered zirconium dioxide, which stays sharp for a long time but is brittle."],"where":[],"whereNote":null,"sources":[{"title":"Kitchen knife","url":"https://en.wikipedia.org/wiki/Kitchen_knife"},{"title":"Stamping (metalworking)","url":"https://en.wikipedia.org/wiki/Stamping_(metalworking)"},{"title":"Forging","url":"https://en.wikipedia.org/wiki/Forging"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"kitchen-sponge","name":"Kitchen sponge","kind":"product","category":"body-health","title":"How kitchen sponges are made","url":"https://assemblyline.org/make/kitchen-sponge","stations":7,"upstream":46,"downstream":0,"depth":8,"dek":"The holes in a cellulose sponge start as salt crystals that melt away inside a hot mold.","answer":"Cellulose sponges start from viscose: wood cellulose dissolved with caustic soda and carbon disulfide. Fibers such as hemp or jute and crystals of sodium sulfate are kneaded in, and the paste fills big molds. Heating solidifies the cellulose while the salt melts and drains out, leaving pores. Blocks are washed, bleached, dried and cut. Synthetic sponges use polyurethane foam instead.","aka":["scrub sponge","cellulose sponge","dish sponge"],"inputs":["wood-pulp","caustic-soda","flax","bleach","water","polyester","adhesive"],"uses":[],"grounds":["flax","water","timber","rock-salt","limestone","air","crude-oil","natural-gas","sulfur","corn","coal","sugarcane","sugar-beet"],"upstreamSlugs":["wood-pulp","caustic-soda","flax","bleach","water","polyester","adhesive","timber","lime","oxygen","hydrogen-peroxide","rock-salt","chlorine","plastic-bottle","pet-plastic","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","limestone","air","hydrogen","sulfuric-acid","p-xylene","ethylene","ethylene-glycol","propylene","ammonia","methanol","phenol","acetone","nitric-acid","crude-oil","natural-gas","sulfur","naphtha","carbon-dioxide","benzene","corn","yeast","toluene","molasses","coal","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Turn cellulose into viscose","process":"react","text":"Cellulose is treated with caustic soda and carbon disulfide in a closed reactor. The product dissolves to a thick liquid called viscose, which ripens and is filtered.","inputs":["wood-pulp","caustic-soda"]},{"name":"Knead in fiber and crystals","process":"mix","text":"Strength-giving fibers such as hemp or jute go in with sodium sulfate crystals. Crystal size decides pore size, with bigger crystals making a coarser sponge.","inputs":["flax"]},{"name":"Heat in big molds","process":"cook","text":"The paste fills large rectangular molds and is heated. The crystals melt and drain through openings in the bottom, while the viscose regenerates into firm, porous cellulose.","inputs":[]},{"name":"Wash and bleach","process":"wash","text":"The blocks soak in a vat of bleach, then rinse in water to remove soluble salts and make the material flexible.","inputs":["bleach","water"]},{"name":"Dry and slice","process":"cut","text":"After drying, an automatic cutting machine slices the big blocks to size. Many plants sell blocks on to converters for this step.","inputs":[]},{"name":"Bond on the scourer","process":"laminate","text":"A scouring pad can be laminated to one face with sponge glue, and antibacterial agents can be added.","inputs":["polyester","adhesive"]},{"name":"Wrap and box","process":"package","text":"Finished sponges are wrapped and boxed for sale.","inputs":[]}],"facts":["Competitors in the ancient Olympic Games bathed with sea sponges soaked in olive oil or perfume.","Some sponges can harbor Salmonella for more than seven days."],"where":[],"whereNote":null,"sources":[{"title":"US2853395A: Cellulosic sponge process","url":"https://patents.google.com/patent/US2853395"},{"title":"Sciencing: How to make cellulose sponges","url":"https://sciencing.com/how-to-make-cellulose-sponges-13640005.html"},{"title":"Sponge (tool)","url":"https://en.wikipedia.org/wiki/Sponge_(tool)"},{"title":"Polyurethane","url":"https://en.wikipedia.org/wiki/Polyurethane"},{"title":"Polyurethane foam","url":"https://en.wikipedia.org/wiki/Polyurethane_foam"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"kite","name":"Kite","kind":"product","category":"play","title":"How kites are made","url":"https://assemblyline.org/make/kite","stations":10,"upstream":50,"downstream":0,"depth":8,"dek":"Kite panels are cut with a hot iron, which seals the fibers so the edges will not fray.","answer":"Hi Fly Kites, a kite wholesaler, walks through its line step by step. Sail fabric is rolled out and panels are cut with a hot iron from templates, 8 of them for one model. Panels shuttle between sewer and cutter up to 5 times. Reinforcements get glued, sleeves and hems sewn, and fiberglass spars and bridle lines added before a final check.","aka":["flying kite","diamond kite","stunt kite"],"inputs":["nylon","polyester","thread","adhesive","fiberglass","carbon-fiber","bamboo","rope"],"uses":[],"grounds":["bamboo","water","silica-sand","limestone","air","natural-gas","crude-oil","rock-salt","trona","coal","sulfur","corn","sugarcane","sugar-beet"],"upstreamSlugs":["nylon","polyester","thread","adhesive","fiberglass","carbon-fiber","bamboo","rope","benzene","nitric-acid","ammonia","pet-plastic","water","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","silica-sand","limestone","soda-ash","propylene","air","polypropylene","naphtha","hydrogen","toluene","natural-gas","p-xylene","ethylene","ethylene-glycol","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","crude-oil","rock-salt","carbon-dioxide","lime","trona","coal","oxygen","sulfur","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Hot-cut the panels","process":"cut","text":"The cutting table takes the fabric off its roll, and templates mark out each panel. A hot iron does the cutting. Modern sails are commonly ripstop nylon or polyester, with reinforcing yarns woven in to stop tears spreading.","inputs":["nylon","polyester"]},{"name":"Cut reinforcements and pockets","process":"cut","text":"Cutters also make extra patches for the nose, spine and wingtips, plus the pockets that will hold the spars.","inputs":[]},{"name":"Sew and trim panels","process":"sew","text":"Center panels are sewn together, wing panels are sewn together, and both return to the cutter for trimming. Wings then join the center and get trimmed to size. Seams have to run straight, so a sail may go back and forth up to 5 times.","inputs":["thread"]},{"name":"Glue and mark","process":"laminate","text":"Those patches get glued on at the nose, spine and wingtips, and a template marks the sail. It gets a check before the last sewing.","inputs":["adhesive"]},{"name":"Sew sleeves and hems","process":"sew","text":"Sleeves for the wing spars go on, the spine tape is sewn down and the trailing edge is hemmed. Pockets and reinforcements follow, and loose threads are cut.","inputs":["thread"]},{"name":"Cut spars and fittings","process":"cut","text":"Fiberglass spars are cut to size, and wing and spine fittings are prepared. Many modern kites use carbon fiber tube or rod, and traditional makers split bamboo.","inputs":["fiberglass","carbon-fiber","bamboo"]},{"name":"Assemble the frame","process":"assemble","text":"Stand-off connectors are fitted at the trailing edge, and the spars go into the skin until the fabric pulls taut.","inputs":[]},{"name":"Set the bridle","process":"assemble","text":"Lines are measured, cut, attached and adjusted. A bridle divides the pull so the face of the kite tilts into the wind.","inputs":["rope"]},{"name":"Inspect it taut","process":"inspect","text":"With the skin stretched, it is easy to spot odd creases. Pockets, sleeves, fittings, end caps, knots and bridle settings each get checked.","inputs":[]},{"name":"Break down and pack","process":"package","text":"Lines are wound on reels and bags are cut and sewn. The kite comes apart for packing and hangs on racks until it ships. Every so often one is pulled at random for a flight test.","inputs":[]}],"facts":["One of the oldest claims for the kite credits two Chinese philosophers in the 5th century BC, who flew wooden ones.","Kite fighters in India, Pakistan and Brazil coat their lines to cut each other's kites out of the sky.","The largest kite built for Japan's Yokaichi festival weighed 3,307 pounds."],"where":[],"whereNote":null,"sources":[{"title":"Cutting of Kite Panels, Hi Fly Kites","url":"https://hiflykites.co.za/cutting/"},{"title":"Sewing and Trimming, Hi Fly Kites","url":"https://hiflykites.co.za/sewing-and-trimming/"},{"title":"Kite Marking, Hi Fly Kites","url":"https://hiflykites.co.za/kite-marking/"},{"title":"Final Sewing, Hi Fly Kites","url":"https://hiflykites.co.za/final-sewing/"},{"title":"Kite Assembly, Hi Fly Kites","url":"https://hiflykites.co.za/?p=354"},{"title":"Kite Packing, Hi Fly Kites","url":"https://hiflykites.co.za/kite-packing/"},{"title":"Kite","url":"https://en.wikipedia.org/wiki/Kite"},{"title":"Ripstop","url":"https://en.wikipedia.org/wiki/Ripstop"},{"title":"Kite types","url":"https://en.wikipedia.org/wiki/Kite_types"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"koji","name":"Koji","kind":"material","category":"food","title":"How koji is made","url":"https://assemblyline.org/make/koji","stations":5,"upstream":3,"downstream":2,"depth":1,"dek":"Koji is steamed grain colonized by a mold that turns starch into sugar, the first step in sake, miso and soy sauce.","answer":"Koji is grain grown over with the mold Aspergillus oryzae. Makers steam rice, soybeans or wheat, seed it with the mold, and keep it warm so the fungus spreads through it. The mold makes enzymes that break starch down into sugar and proteins into amino acids, which feed later fermentation.","aka":["kōji","Aspergillus oryzae","rice koji"],"inputs":["rice","soybeans","wheat"],"uses":["soy-sauce","sake"],"grounds":["rice","soybeans","wheat"],"upstreamSlugs":["rice","soybeans","wheat"],"downstreamSlugs":["soy-sauce","sake"],"steps":[{"name":"Steam the grain","process":"cook","text":"Rice is steamed and loosened so each grain is soft but not mushy. Soybeans and wheat are also used for different foods.","inputs":["rice","soybeans","wheat"]},{"name":"Sprinkle on the mold spores","process":"mix","text":"Once the grain has cooled, spores of Aspergillus oryzae are dusted over it and mixed in.","inputs":[]},{"name":"Keep it warm while it grows","process":"grow","text":"The inoculated grain rests for two to three days in a warm, humid room as the mold grows through each kernel. Solid-state cultivation of this kind is thought to have started in China.","inputs":[],"spec":"two to three days at 30 °C"},{"name":"Turn and cool the batch","process":"knead","text":"Workers turn the mass so it does not overheat, since the growing mold gives off heat. Even temperature gives an even growth.","inputs":[]},{"name":"Break it up and use it","process":"knead","text":"Finished koji is broken apart and mixed into steamed rice for sake, or into soybeans for soy sauce and miso. The mold's enzymes saccharify the starch.","inputs":[]}],"facts":["Aspergillus oryzae is used in East Asia to saccharify rice, sweet potato and barley for sake and shochu.","For soy sauce and miso, a related mold called Aspergillus sojae is sometimes used."],"where":[],"whereNote":null,"sources":[{"title":"Aspergillus oryzae","url":"https://en.wikipedia.org/wiki/Aspergillus_oryzae"},{"title":"Jiuqu","url":"https://en.wikipedia.org/wiki/Jiuqu"},{"title":"Kōji (food)","url":"https://en.wikipedia.org/wiki/Koji_(food)"},{"title":"Sake","url":"https://en.wikipedia.org/wiki/Sake"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"kombucha","name":"Kombucha","kind":"product","category":"drink","title":"How kombucha is made","url":"https://assemblyline.org/make/kombucha","stations":5,"upstream":25,"downstream":0,"depth":6,"dek":"A jellyfish-like mat of bacteria and yeast turns sweet tea sour, and a new mat grows on top every batch.","answer":"Kombucha is made by steeping tea in sugar water, cooling it, and adding a living culture of bacteria and yeast along with some already fermented kombucha. The jar sits at room temperature for up to 14 days while the microbes convert sugar into acids and a little alcohol. A new culture mat forms on the surface.","aka":["fermented tea","tea mushroom drink"],"inputs":["tea","sugar","water","glass-bottle"],"uses":[],"grounds":["water","tea-leaves","sugarcane","sugar-beet","silica-sand","limestone","rock-salt","trona","natural-gas","air","corn","crude-oil"],"upstreamSlugs":["tea","sugar","water","glass-bottle","tea-leaves","sugarcane","sugar-beet","lime","silica-sand","soda-ash","limestone","polyethylene","rock-salt","ammonia","carbon-dioxide","trona","ethylene","natural-gas","air","corn","yeast","naphtha","molasses","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Steep the sweet tea","process":"cook","text":"Sugar is dissolved in non-chlorinated boiling water and tea leaves are steeped in it. The leaves are then removed, leaving sweet tea.","inputs":["tea","sugar","water"]},{"name":"Cool and add the culture","process":"mix","text":"Once cool, the tea is poured into a sterilized vessel with the culture of bacteria and yeast, called the mother, plus some previously fermented kombucha.","inputs":[]},{"name":"Ferment at room temperature","process":"ferment","text":"The yeast turns sugar into alcohol, and the acetic acid bacteria turn that alcohol into acids. A daughter culture forms across the top, growing to the width of the container.","inputs":[],"spec":"10 to 14 days, 18 to 26 °C"},{"name":"Pull the culture out","process":"separate","text":"The culture is lifted out and stored with a little of the new tea, ready to start the next batch.","inputs":[]},{"name":"Bottle with flavors","process":"fill","text":"Juice, spices or fruit can be added before bottling. The drink carries on fizzing a little in the sealed bottle.","inputs":["glass-bottle"]}],"facts":["The stories that kombucha was served to a Chinese emperor in the Qin dynasty have no evidence behind them.","Dried kombucha culture becomes a leather-like microbial cellulose that can be molded into clothing.","The alcohol content is usually below 0.5 percent but rises the longer the tea ferments."],"where":[],"whereNote":null,"sources":[{"title":"Kombucha","url":"https://en.wikipedia.org/wiki/Kombucha"},{"title":"Black tea","url":"https://en.wikipedia.org/wiki/Black_tea"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"synthetic-diamond","name":"Lab-grown diamond","kind":"product","category":"hardware","title":"How lab-grown diamonds are made","url":"https://assemblyline.org/make/synthetic-diamond","stations":6,"upstream":5,"downstream":0,"depth":3,"dek":"A Swedish team made diamond in 1953 and stayed quiet until after General Electric went public in 1955.","answer":"Lab-grown diamonds are made two ways. In a giant press, carbon dissolves in molten metal around 1,500 °C and crystallizes on tiny diamond seeds. In a sealed chamber, energized methane and hydrogen form a plasma, and carbon settles on a thin seed plate layer by layer. Both take weeks or less, and the rough is then sawn, cut and polished like a mined stone.","aka":["synthetic diamond","laboratory-grown diamond","CVD diamond","HPHT diamond"],"inputs":["synthetic-graphite","natural-gas"],"uses":[],"grounds":["natural-gas","crude-oil","coal"],"upstreamSlugs":["synthetic-graphite","natural-gas","crude-oil","petroleum-coke","coal"],"downstreamSlugs":[],"steps":[{"name":"Prepare the carbon source","process":"mix","text":"Pressure growth packs high-purity carbon such as graphite beside a solvent metal such as nickel. Vapor growth feeds in a gas mix that is typically 1 part methane to 99 parts hydrogen.","inputs":["synthetic-graphite","natural-gas"]},{"name":"Squeeze and heat","process":"press","text":"In the high-pressure route, a belt, cubic or split-sphere press clamps the cell between hard anvils, reaching about 5 GPa. Current through the anvils heats it above 1,400 °C and melts the metal.","inputs":[],"spec":"5 GPa at about 1,500 °C"},{"name":"Crystallize on seeds","process":"grow","text":"The molten metal dissolves the carbon and carries it to small seeds at the bottom of the press, where it precipitates as a growing crystal. A stone takes days to a few weeks.","inputs":[]},{"name":"Or deposit from plasma","process":"deposit","text":"In the vapor route, microwaves or another energy source ionize the gas above a substrate kept at about 800 °C. Carbon settles on a thin seed layer by layer, while hydrogen etches away any non-diamond carbon.","inputs":[],"spec":"about 800 °C substrate"},{"name":"Assess the rough","process":"inspect","text":"The rough crystal comes out of the press or chamber and is assessed. Stones from a press can hold inclusions from the nickel, and chamber materials can contaminate plasma-grown ones.","inputs":[]},{"name":"Saw, cut and polish","process":"grind","text":"From here the work matches that on mined stones: rough gets cleaved or sawn, cutters polish it on the same kinds of wheels, and it is later graded on the usual four measures.","inputs":[]}],"facts":["Sweden's ASEA made the first known synthetic diamond on February 16, 1953, but its board chose not to publicize or patent it.","Howard Tracy Hall at General Electric achieved the first commercially successful diamond synthesis on December 16, 1954.","Lab-grown stones mostly stayed under half a carat until about 2010."],"where":[],"whereNote":null,"sources":[{"title":"Synthetic diamond","url":"https://en.wikipedia.org/wiki/Synthetic_diamond"},{"title":"Diamond","url":"https://en.wikipedia.org/wiki/Diamond"},{"title":"How Are Lab-Grown Diamonds Made?, Reve Diamonds","url":"https://www.revediamonds.com/us/blog/how-are-lab-grown-diamonds-made-a-comprehensive-guide"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lacquer","name":"Lacquer","kind":"material","category":"chemicals","title":"How lacquer is made","url":"https://assemblyline.org/make/lacquer","stations":8,"upstream":19,"downstream":65,"depth":5,"dek":"True lacquer is tree sap that hardens into glossy armor in warm, damp air.","answer":"Asian lacquer starts as sap scraped from cuts in the bark of Toxicodendron vernicifluum, in Japan about 180 grams from a tree that took 10 years to grow. Refiners strain out wood particles, whip the sap smooth, then stir and heat it to drive off water. Coats harden in a humid cabinet. Modern lacquers instead dry as a solvent evaporates.","aka":["urushi","Asian lacquer","lacquerware finish"],"inputs":["ethanol","acrylic"],"uses":["tin-can","guitar","electric-guitar","trumpet","chopsticks","door","chess-set","saxophone","ukulele","felt-hat","vinyl-record","compact-disc","baseball-bat"],"grounds":["corn","sugarcane","water","natural-gas","crude-oil","air","sulfur","sugar-beet"],"upstreamSlugs":["ethanol","acrylic","corn","sugarcane","water","yeast","ethylene","propylene","ammonia","sulfuric-acid","methanol","molasses","naphtha","natural-gas","crude-oil","air","sulfur","sugar-beet","hydrogen"],"downstreamSlugs":["tin-can","guitar","electric-guitar","trumpet","chopsticks","door","chess-set","saxophone","ukulele","felt-hat","vinyl-record","compact-disc","baseball-bat","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","scissors","mirror","car","electric-car","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","golf-ball","wallpaper","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","padlock"],"steps":[{"name":"Score the bark","process":"harvest","text":"Harvesters slice several horizontal grooves into the bark, then gather the sap the tree pushes out to heal them. In Japan a tree gives about 180 grams and is harvested only once. The sap contains urushiol, a skin allergen until cured.","inputs":[],"spec":"about 180 grams per tree"},{"name":"Strain out the wood","process":"separate","text":"Wood particles are removed from the collected sap. Now called kiurushi, or raw lacquer, it can already serve as a base coat on wooden vessels.","inputs":[]},{"name":"Whip it smooth","process":"mix","text":"A step called nayashi whips the raw lacquer into an even mixture.","inputs":[]},{"name":"Stir over gentle heat","process":"cook","text":"The kurome step stirs and warms the sap slowly until excess water evaporates. What remains is a see-through, brownish, viscous coating material called refined lacquer.","inputs":[]},{"name":"Tint the refined sap","process":"mix","text":"The refined sap is dyed for colored lacquerware. Japan imports 98% of its lacquer now, mostly from China.","inputs":[]},{"name":"Or dissolve a resin","process":"mix","text":"Modern lacquers dissolve shellac or synthetic polymer, such as nitrocellulose or acrylic resin, in a thinner. Shellac-based types use alcohol.","inputs":["ethanol","acrylic"]},{"name":"Brush on thin coats","process":"coat","text":"Lacquer goes on in several coats over a base, usually wood. Each layer stays thin so it can set properly.","inputs":[]},{"name":"Cure in a humid cabinet","process":"dry","text":"Sap coatings do not really dry, since no solvent is involved. They harden over several days inside a humid cabinet known as an urushiburo. Modern lacquers harden as their solvent leaves.","inputs":[]}],"facts":["The word urushiol comes from the Japanese name of the lacquer tree.","Compared with oil-based or latex paint, a modern lacquer finish usually dries harder and snaps more easily.","The English word lacquer traces back through Portuguese and Arabic to the Sanskrit word for lac."],"where":[],"whereNote":null,"sources":[{"title":"Daigo Urushi: Japan's Top Lacquer, Nippon.com","url":"https://www.nippon.com/en/articles/-/12489"},{"title":"Lacquerware, The Japanese Table, Kikkoman","url":"https://www.kikkoman.com/en/culture/foodforum/the-japanese-table/40-2_japanese_tableware.html"},{"title":"Lacquer","url":"https://en.wikipedia.org/wiki/Lacquer"},{"title":"Urushiol","url":"https://en.wikipedia.org/wiki/Urushiol"},{"title":"Urushi","url":"https://en.wikipedia.org/wiki/Urushi"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"laminate-floor","name":"Laminate flooring","kind":"product","category":"wood-paper","title":"How laminate flooring is made","url":"https://assemblyline.org/make/laminate-floor","stations":6,"upstream":60,"downstream":0,"depth":8,"dek":"Laminate flooring is mostly wood waste, with a photograph of wood fused on top.","answer":"Sawdust and wood chips are ground, mixed with resin and pressed into dense fiberboard. A high-resolution photo of wood grain is printed on resin-soaked paper. The core, a stabilizing backing, the photo layer and a clear wear layer are stacked and pressed together under heat until the resin sets. The big sheet is cut into planks with locking edges.","aka":["laminate floor","floating floor"],"inputs":["lumber","adhesive","melamine-resin","paper","ink","alumina"],"uses":[],"grounds":["timber","water","kaolin","limestone","bauxite","crude-oil","natural-gas","air","corn","soybeans","rapeseed","clay","titanium-ore","iron-ore","sulfur","sugarcane","rock-salt","coal","sugar-beet"],"upstreamSlugs":["lumber","adhesive","melamine-resin","paper","ink","alumina","timber","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","ammonia","carbon-dioxide","formaldehyde","wood-pulp","kaolin","limestone","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","bauxite","caustic-soda","lime","ethylene","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","hydrogen","natural-gas","air","corn","yeast","oxygen","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","titanium-ore","coke","iron-ore","sulfur","sugarcane","rock-salt","naphtha","benzene","molasses","coal","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Press the fiberboard core","process":"press","text":"Sawdust, chips and other leftovers from wood factories are ground up, mixed with melamine resin and dried, then formed into panels of high-density fiberboard. This is the thick middle layer that gives the plank its strength.","inputs":["lumber","adhesive","melamine-resin"],"spec":"6 to 12 mm thick"},{"name":"Print the wood-grain photo","process":"print","text":"A sharp photograph of a plank, or of tile or stone, is printed on paper. The paper is soaked in melamine resin so it will fuse with the layers around it.","inputs":["paper","ink","melamine-resin"]},{"name":"Add the backing sheet","process":"coat","text":"A backing sheet of paper or melamine plastic goes on the underside to balance the top layers and keep the plank from warping. It also blocks moisture rising from the floor below.","inputs":["paper","melamine-resin"]},{"name":"Add the clear wear layer","process":"coat","text":"The top is a clear coating of melamine, aluminum oxide, or both. It takes the scuffs and scratches so the picture underneath stays intact.","inputs":["alumina","melamine-resin"]},{"name":"Stack and hot-press","process":"laminate","text":"Core, backing, photo and wear layer are stacked and pressed with great force at nearly 400 degrees Fahrenheit, so the resin cures into a solid plastic. In the one-step direct-pressure method this all happens at once.","inputs":[],"spec":"over 600 psi, nearly 400 °F"},{"name":"Cut planks and locking edges","process":"machine","text":"The large pressed boards are cut into planks. Special cutters shape tongues and grooves on all four edges, so planks snap into each other.","inputs":[]}],"facts":["Direct-pressure laminate is made in one pressing, while high-pressure laminate presses its top layers separately onto kraft paper first, at over 1000 psi.","Laminate's clear top coat is often advertised as the second hardest substance after diamond, and that claim is not quite right."],"where":[],"whereNote":null,"sources":[{"title":"How Laminate Is Made","url":"https://www.floorstoyourhome.com/resource-center/laminate-flooring/how-laminate-is-made/"},{"title":"Laminate flooring","url":"https://en.wikipedia.org/wiki/Laminate_flooring"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"laptop","name":"Laptop","kind":"product","category":"electronics","title":"How laptops are made","url":"https://assemblyline.org/make/laptop","stations":6,"upstream":106,"downstream":0,"depth":10,"dek":"A 1981 Epson with an LCD, a battery and a built-in printer was already being called a laptop.","answer":"A laptop is assembled in a metal or plastic clamshell. The motherboard, memory and storage are fixed into the lower half, where most of the hardware lives. A keyboard and trackpad go on top, a lithium-ion battery fills much of the underside, and a hinged lid carries the flat-panel screen.","aka":["notebook computer","notebook","portable computer"],"inputs":["printed-circuit-board","microchip","memory-chip","abs-plastic","aluminum","solid-state-drive","lithium-ion-cell","computer-keyboard","lcd-screen"],"uses":[],"grounds":["air","crude-oil","coal","copper-ore","water","silica-sand","limestone","quartz","tin-ore","gold-ore","natural-gas","iron-ore","sulfur","bauxite","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","natural-latex","rock-salt","trona","lead-ore","silver-ore","zinc-ore","titanium-ore","dolomite","corn","timber","sugarcane","sugar-beet"],"upstreamSlugs":["printed-circuit-board","microchip","memory-chip","abs-plastic","aluminum","solid-state-drive","lithium-ion-cell","computer-keyboard","lcd-screen","copper","fiberglass","epoxy","photoresist","solder","silicon-wafer","oxygen","tin","gold","nitrogen","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","crude-oil","coal","petroleum-coke","alumina","lithium-carbonate","cobalt","nickel","manganese","synthetic-graphite","polyethylene","steel","rubber","glass","indium-tin-oxide","led","acrylic","copper-ore","water","sulfuric-acid","silica-sand","limestone","soda-ash","phenol","acetone","chlorine","caustic-soda","phenolic-resin","lead","silver","polysilicon","quartz","argon","tin-ore","coke","gold-ore","lime","zinc","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","carbon-black","sulfur","bauxite","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","pig-iron","magnesium","steel-scrap","natural-latex","synthetic-rubber","indium","gallium","plastic","methanol","rock-salt","carbon-dioxide","trona","formaldehyde","lead-ore","silver-ore","zinc-ore","silicon","hydrochloric-acid","trichlorosilane","titanium-ore","dolomite","propane","corn","yeast","charcoal","timber","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Build the motherboard","process":"assemble","text":"Surface-mount machines populate a multilayer board with the processor and memory, and a reflow oven solders them.","inputs":["printed-circuit-board","microchip","memory-chip"]},{"name":"Mold or machine the case","process":"mold","text":"The lower and upper halves of the case are molded in plastic or machined from metal.","inputs":["abs-plastic","aluminum"]},{"name":"Fit storage and battery","process":"assemble","text":"A solid-state drive and a rechargeable lithium-ion battery are fitted in the base.","inputs":["solid-state-drive","lithium-ion-cell"]},{"name":"Install keyboard and trackpad","process":"assemble","text":"A thin keyboard, usually with scissor switches, and a trackpad go in the top of the base.","inputs":["computer-keyboard"]},{"name":"Hinge on the display","process":"assemble","text":"The flat-panel screen, usually 11 to 17 inches diagonally, goes in the lid with a webcam above it.","inputs":["lcd-screen"]},{"name":"Load and burn in","process":"inspect","text":"Software is installed and the machine is run for hours to find early failures before shipping.","inputs":[]}],"facts":["Seiko Epson showed an early machine called a laptop in 1981 with an LCD screen, a rechargeable battery and a built-in printer, weighing 1.6 kg.","Laptop keyboards more often use scissor switches than the rubber domes common on full-size keyboards.","Most of a laptop's hardware sits in the lower half under the keyboard, and the lid holds little besides the screen."],"where":[],"whereNote":null,"sources":[{"title":"Laptop","url":"https://en.wikipedia.org/wiki/Laptop"},{"title":"Computer keyboard","url":"https://en.wikipedia.org/wiki/Computer_keyboard"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"detergent","name":"Laundry detergent","kind":"product","category":"body-health","title":"How laundry detergent is made","url":"https://assemblyline.org/make/detergent","stations":7,"upstream":62,"downstream":0,"depth":10,"dek":"Powdered detergent is sprayed as a hot slurry down a tower and lands as dry hollow beads.","answer":"Laundry detergent is a cleaning surfactant blended with builders that soften water, plus bleach, enzymes and fragrance. Powders start as a hot slurry that is sprayed from the top of a tall tower, where hot air dries the droplets into hollow beads. Liquids are simply mixed in tanks and bottled.","aka":["washing powder","laundry soap","washing liquid"],"inputs":["vegetable-oil","crude-oil","sulfuric-acid","caustic-soda","soda-ash","water","cardboard-box","plastic-bottle"],"uses":[],"grounds":["crude-oil","water","soybeans","rapeseed","clay","sulfur","air","rock-salt","limestone","trona","natural-gas","corn","timber","titanium-ore","iron-ore","sugarcane","sugar-beet","coal"],"upstreamSlugs":["vegetable-oil","crude-oil","sulfuric-acid","caustic-soda","soda-ash","water","cardboard-box","plastic-bottle","soybeans","rapeseed","hexane","clay","sulfur","air","rock-salt","ammonia","limestone","carbon-dioxide","lime","trona","cardboard","ink","adhesive","pet-plastic","hydrogen","natural-gas","corn","yeast","wood-pulp","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","p-xylene","ethylene","ethylene-glycol","molasses","timber","oxygen","hydrogen-peroxide","phenol","formaldehyde","titanium-ore","chlorine","coke","iron-ore","sugarcane","propylene","methanol","acetone","nitric-acid","naphtha","sugar-beet","benzene","coal","toluene"],"downstreamSlugs":[],"steps":[{"name":"Make the surfactant","process":"react","text":"Oils or petrochemicals are turned into molecules with an oily end and a water-loving end, usually sulfonated or sulfated. These do most of the cleaning, lifting greasy dirt into the wash water.","inputs":["vegetable-oil","crude-oil","sulfuric-acid"]},{"name":"Neutralize it","process":"react","text":"The acid form of the surfactant is neutralized with caustic soda or soda ash. That makes it a stable salt that dissolves in water.","inputs":["caustic-soda","soda-ash"]},{"name":"Mix the slurry","process":"mix","text":"Surfactant, builder salts that tie up the minerals in hard water, and a filler are stirred with water into a thick, hot slurry.","inputs":["water"]},{"name":"Spray into the tower","process":"dry","text":"A pump forces the slurry through nozzles at the top of a tall tower. Hot air rises through the falling spray and dries each droplet into a hollow bead.","inputs":[]},{"name":"Dose the delicate parts","process":"mix","text":"Heat-sensitive ingredients such as enzymes, bleach and fragrance are added after drying. Spray-drying would destroy them.","inputs":[]},{"name":"Mix the liquid kind","process":"mix","text":"For liquid detergent, the same ingredients are stirred into water in tanks. Thickeners and dyes are checked and the liquid is filtered.","inputs":[]},{"name":"Fill and box","process":"fill","text":"Powder goes into cartons and liquid into plastic jugs on high-speed lines. Both are weighed and packed into cases.","inputs":["cardboard-box","plastic-bottle"]}],"facts":["Laundry detergents can contain about 50% builders by weight, 15% surfactants, 7% bleach and 2% enzymes.","By volume, powdered detergents sell about twice as much as liquids worldwide.","German chemical companies developed an alkyl sulfate surfactant in 1917 in response to shortages of soap ingredients during World War I."],"where":[],"whereNote":null,"sources":[{"title":"Laundry detergent","url":"https://en.wikipedia.org/wiki/Laundry_detergent"},{"title":"Surfactant","url":"https://en.wikipedia.org/wiki/Surfactant"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lcd-screen","name":"LCD screen","kind":"product","category":"electronics","title":"How LCD screens are made","url":"https://assemblyline.org/make/lcd-screen","stations":6,"upstream":54,"downstream":4,"depth":9,"dek":"Liquid crystals were discovered in 1888 in a form of cholesterol extracted from carrots.","answer":"An LCD is two big glass sheets joined with liquid crystal between them. One sheet carries a grid of thin-film transistors. The other carries red, green and blue color filters printed with pigmented photoresist. After the sheets are glued, cut into panels and fitted with polarizers, a backlight of LEDs is added behind.","aka":["liquid crystal display","TFT LCD","flat panel display"],"inputs":["glass","indium-tin-oxide","photoresist","pigment","led","acrylic"],"uses":["laptop","television","smartwatch","digital-camera"],"grounds":["silica-sand","limestone","iron-ore","sulfur","rock-salt","water","trona","zinc-ore","tin-ore","titanium-ore","crude-oil","air","bauxite","natural-gas","gold-ore","corn","coal","sugarcane","sugar-beet"],"upstreamSlugs":["glass","indium-tin-oxide","photoresist","pigment","led","acrylic","silica-sand","soda-ash","limestone","indium","tin","phenolic-resin","iron-ore","titanium-dioxide","carbon-black","sulfur","gallium","ammonia","hydrogen","gold","plastic","propylene","sulfuric-acid","methanol","rock-salt","water","carbon-dioxide","lime","trona","zinc-ore","tin-ore","coke","phenol","formaldehyde","titanium-ore","chlorine","oxygen","crude-oil","air","bauxite","caustic-soda","natural-gas","gold-ore","zinc","naphtha","ethylene","corn","yeast","coal","benzene","molasses","toluene","sugarcane","sugar-beet"],"downstreamSlugs":["laptop","television","smartwatch","digital-camera"],"steps":[{"name":"Pattern transistors on glass","process":"etch","text":"A large sheet of glass is coated with thin films and etched into a grid of thin-film transistors, one for each subpixel, with transparent electrodes of indium tin oxide.","inputs":["glass","indium-tin-oxide","photoresist"]},{"name":"Print the color filters","process":"print","text":"On a second glass sheet, black photoresist is applied first, exposed to ultraviolet through a mask and washed to leave a black grid. Red, green and blue resists then fill the holes in turn. Their pigment particles are just 40 nm wide.","inputs":["glass","photoresist","pigment"],"spec":"40 nm pigment particles"},{"name":"Glue the sheets with crystal inside","process":"laminate","text":"The two sheets are glued together with spacers and liquid crystal sandwiched between. In a twisted nematic panel, alignment layers on the inside surfaces make the molecules lie in a twist when no voltage is applied.","inputs":[]},{"name":"Cut the big sheet","process":"cut","text":"Several finished cells share one large pair of sheets, and they are cut apart into individual screens.","inputs":[]},{"name":"Stick on polarizers","process":"laminate","text":"Polarizing sheets go on the front and back with their axes crossed. A pixel then passes light only when the liquid crystal twists its polarization.","inputs":[]},{"name":"Add the LED backlight","process":"assemble","text":"Liquid crystals do not make light. A row of white LEDs along the edge shines into a light guide plate, usually of acrylic, which spreads it evenly behind the panel.","inputs":["led","acrylic"]}],"facts":["Each color filter pigment is ground to particles only 40 nanometers across.","Backlights using cold cathode fluorescent lamps needed about 1,000 volts, so thin screens needed bulky inverters."],"where":[],"whereNote":null,"sources":[{"title":"Liquid-crystal display","url":"https://en.wikipedia.org/wiki/Liquid-crystal_display"},{"title":"Television set","url":"https://en.wikipedia.org/wiki/Television_set"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lead","name":"Lead","kind":"material","category":"metals","title":"How lead is made","url":"https://assemblyline.org/make/lead","stations":6,"upstream":9,"downstream":86,"depth":3,"dek":"More lead now comes from recycling, mostly old batteries, than from the ground.","answer":"Lead is made from galena, a lead sulfide. The ore is crushed and floated to a concentrate, which is smelted with coke into crude lead bullion. Zinc is added to pull out silver and gold, other impurities are skimmed off, and the clean lead is cast. In 2014 recycling gave 5.64 million tonnes, against 4.58 million from ore.","aka":["refined lead","pig lead","lead bullion"],"inputs":["lead-ore","coke","zinc"],"uses":["brass","solder","chess-set","stained-glass","car-battery","sailboat"],"grounds":["lead-ore","coal","zinc-ore","air","sulfur","water"],"upstreamSlugs":["lead-ore","coke","zinc","coal","zinc-ore","air","sulfuric-acid","sulfur","water"],"downstreamSlugs":["brass","solder","chess-set","stained-glass","car-battery","sailboat","aa-battery","wristwatch","faucet","padlock","tire","electric-guitar","trumpet","ballpoint-pen","pencil-eraser","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","light-switch","power-outlet","leather-belt","handbag","flag","phone-charger","usb-cable","zipper","hearing-aid","pacemaker","printed-circuit-board","led-bulb","solid-state-drive","solar-panel","refrigerator","drone","air-conditioner","flute","smoke-detector","eyeglass-frame","smartwatch","wireless-earbuds","microphone","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","car","electric-car","bicycle","motorcycle","down-jacket","raincoat","backpack","suitcase","jeans","thermometer","ev-battery","smartphone","laptop","television","hard-drive","computer-keyboard","computer-mouse","wind-turbine","microwave-oven","washing-machine","satellite","airbag","airplane","rocket","locomotive","elevator","blender","ceiling-fan","treadmill","pinball-machine","digital-camera","e-reader","skyscraper"],"steps":[{"name":"Crush the galena ore","process":"crush","text":"Lead ore, mainly galena, is mostly found with zinc ores. It is crushed and ground so the lead mineral is freed from the rock.","inputs":["lead-ore"]},{"name":"Float a concentrate","process":"separate","text":"Froth flotation lifts the lead sulfide off the waste rock to give a concentrate that is rich in lead.","inputs":[]},{"name":"Smelt it with carbon","process":"melt","text":"The sulfide is oxidized to lead oxide in a furnace, then reduced to metal with coke or coal gas. Lead bullion collects below a layer of slag that holds the leftovers. Lead melts at only 327.5 °C.","inputs":["coke"]},{"name":"Skim off the impurities","process":"refine","text":"Air, steam or sulfur is blown through the melt in a furnace. Arsenic, antimony, copper and other metals oxidize and float to the top, where they are skimmed away.","inputs":[]},{"name":"Pull out the silver with zinc","process":"refine","text":"Zinc is stirred into the molten lead, in what is called the Parkes process. Silver and gold dissolve into the zinc, which is separated and sent on to recover the precious metals.","inputs":["zinc"]},{"name":"Cast the refined lead","process":"cast","text":"Clean lead is cast into ingots for battery makers and others. For the purest lead, an electrolytic route called the Betts process plates it from an impure anode onto a pure cathode.","inputs":[]}],"facts":["Lead was first smelted in the 7th millennium BC, because it is so easily worked and turns up with silver ores.","Interest in silver helped start widespread lead mining in ancient Rome.","Lead from secondary production is indistinguishable from lead made from ore, so the two can be mixed in the same plant."],"where":[],"whereNote":null,"sources":[{"title":"Lead","url":"https://en.wikipedia.org/wiki/Lead"},{"title":"Smelting","url":"https://en.wikipedia.org/wiki/Smelting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lead-ore","name":"Lead ore","kind":"raw","category":"ground","title":"How lead ore is mined","url":"https://assemblyline.org/make/lead-ore","stations":4,"upstream":0,"downstream":95,"depth":0,"dek":"Galena is 86.6% lead, yet the rock it sits in usually gives up only about 4%.","answer":"Lead ore is a thin prize in a lot of rock. Miners pull galena from veins and lodes, often alongside zinc and silver, and a mill crushes it as fine as 0.1 mm. Churned with water, air and chemicals, the sulfide grains rise in an oily froth that is skimmed and dried. Concentrate reaches the smelter at 40 to 80% lead or more.","aka":["galena","lead glance"],"inputs":[],"uses":["lead","silver"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["lead","silver","brass","solder","chess-set","stained-glass","car-battery","sailboat","solar-cell","coin","gold-ring","mirror","trumpet","thermos","flute","saxophone","medal","light-switch","smoke-detector","vinyl-record","aa-battery","wristwatch","faucet","padlock","tire","electric-guitar","ballpoint-pen","pencil-eraser","fountain-pen","garden-hose","harmonica","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","power-outlet","leather-belt","handbag","flag","phone-charger","usb-cable","zipper","hearing-aid","pacemaker","printed-circuit-board","led-bulb","solid-state-drive","solar-panel","refrigerator","drone","air-conditioner","eyeglass-frame","smartwatch","wireless-earbuds","microphone","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","car","electric-car","bicycle","motorcycle","down-jacket","raincoat","backpack","suitcase","jeans","thermometer","ev-battery","smartphone","laptop","television","hard-drive","computer-keyboard","computer-mouse","wind-turbine","microwave-oven","washing-machine","satellite","airbag","airplane","rocket","locomotive","elevator","blender","ceiling-fan","treadmill","pinball-machine","digital-camera","e-reader","skyscraper"],"steps":[{"name":"Dig veins and lodes","process":"mine","text":"Ore comes from narrow veins and rounded lodes, usually about 60 m down, though big mixed deposits go far deeper. Mount Isa in Australia opens large sections by stoping from sub-levels and backfills the voids with process waste, rock and cement.","inputs":[]},{"name":"Crush it fine","process":"crush","text":"Concentrating mills reduce the rock until the galena comes free of its waste, sometimes to particles under 0.1 mm across.","inputs":[],"spec":"under 0.1 mm"},{"name":"Float the sulfide grains","process":"separate","text":"Crushed ore is diluted with water and beaten with air in a tank dosed with pine oil or similar chemicals. Sulfide grains rise in an oily froth, and the mostly worthless rock sinks. Alum and lime help the fine particles clump together, and xanthate helps them float.","inputs":[]},{"name":"Dry the concentrate","process":"dry","text":"Froth flows off the tank and is dried for shipping. The dried concentrate can still carry up to 30% sulfur and up to 15% zinc, which the smelter has to remove.","inputs":[]}],"facts":["In some deposits galena carries up to 0.5% silver, a by-product that far surpasses the lead in revenue.","Galena can be smelted in an ordinary wood fire, which is why humans used lead from the earliest times.","Zinc and silver mines yield nearly 90% of primary lead ore as a side product."],"where":[{"place":"China","share":"first in mined lead concentrate"},{"place":"Australia","share":"second"},{"place":"United States","share":"third"}],"whereNote":"Ranked by mined lead concentrate in 2014.","sources":[{"title":"Lead processing: Mining and concentrating","url":"https://www.britannica.com/technology/lead-processing/Mining-and-concentrating"},{"title":"Lead processing","url":"https://www.britannica.com/technology/lead-processing"},{"title":"Mount Isa Lead/Zinc Mine","url":"https://www.mining-technology.com/projects/mount_isla_lead/"},{"title":"Galena","url":"https://en.wikipedia.org/wiki/Galena"},{"title":"Lead","url":"https://en.wikipedia.org/wiki/Lead"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"leather","name":"Leather","kind":"material","category":"textiles","title":"How leather is made","url":"https://assemblyline.org/make/leather","stations":6,"upstream":26,"downstream":15,"depth":6,"dek":"A hide is rotting the moment it comes off the animal, and tanning permanently locks its protein so it never rots.","answer":"Leather is animal hide whose protein has been permanently chemically changed. Hides are salted, soaked, limed to loosen hair, fleshed, and bathed in a tanning agent, mostly chromium salts. Afterward the hide is split, dyed, oiled and dried, and it no longer decays.","aka":["tanned hide","cowhide leather","chrome-tanned leather"],"inputs":["cattle-hide","rock-salt","water","lime","chromium"],"uses":["wristwatch","baseball","basketball","ice-skates","tennis-racket","football","saxophone","winter-gloves","leather-belt","handbag","wallet","hiking-boots","high-heels","digital-camera","leather-shoe"],"grounds":["cattle-hide","rock-salt","water","limestone","chromite","air","coal","trona","crude-oil","natural-gas","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["cattle-hide","rock-salt","water","lime","chromium","limestone","chromite","coke","soda-ash","air","aluminum","coal","ammonia","carbon-dioxide","trona","crude-oil","petroleum-coke","alumina","natural-gas","corn","yeast","bauxite","caustic-soda","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["wristwatch","baseball","basketball","ice-skates","tennis-racket","football","saxophone","winter-gloves","leather-belt","handbag","wallet","hiking-boots","high-heels","digital-camera","leather-shoe"],"steps":[{"name":"Salt the hides","process":"dry","text":"Fresh hides are cured with salt as soon as possible. Salt draws out water by osmosis and stops bacteria from eating the collagen before the hides reach the tannery.","inputs":["cattle-hide","rock-salt"]},{"name":"Soak them soft","process":"wash","text":"In a rotating drum, clean water washes the salt out and puts the water back so the hide can be treated.","inputs":["water"]},{"name":"Lime off the hair","process":"react","text":"Milk of lime makes the hide swell, loosens the hair and breaks the bonds that hold it in place. Machines then strip the hair and scrape off fat and flesh from the underside.","inputs":["lime"]},{"name":"Bate and pickle","process":"react","text":"The lime is washed out, enzymes soften the hide and a salt and acid bath lowers its pH so the tanning agent can get in.","inputs":["rock-salt"]},{"name":"Tan with chromium","process":"react","text":"Chromium(III) sulfate is added to the drum. It forms bridges between the collagen chains, and the bath is then made less acidic so the bonds lock in. The pale blue result is called wet blue. Chrome tanning takes about a day and makes most of the world's leather.","inputs":["chromium"],"spec":"about 1 day"},{"name":"Crust, dye and finish","process":"dye","text":"The tanned hide is split to thickness, shaved, dyed, oiled, then dried and softened. A surface finish can be added, including buffing flaws away and embossing a grain.","inputs":[]}],"facts":["Chrome tanning accounts for 85 to 90 percent of modern leather making.","Traditional tanning stank so badly that tanneries were pushed to the outskirts of towns."],"where":[{"place":"China","share":"one of the two leading producers"},{"place":"India","share":"one of the two leading producers"}],"whereNote":"Today, per Wikipedia; no year or quantity is given.","sources":[{"title":"Leather","url":"https://en.wikipedia.org/wiki/Leather"},{"title":"Tanning (leather)","url":"https://en.wikipedia.org/wiki/Tanning_(leather)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"leather-belt","name":"Leather belt","kind":"product","category":"textiles","title":"How leather belts are made","url":"https://assemblyline.org/make/leather-belt","stations":10,"upstream":85,"downstream":0,"depth":10,"dek":"One maker bevels every strap twice and spaces its holes about 5/8 inch apart, not the usual inch.","answer":"Full sides of vegetable-tanned hide, about 8 feet long at one Scottsdale shop, are inspected, blocked and run through a strap cutter. The buckle end is skived thin, edges are beveled, holes punched, and coats of edge dye burnished while tacky. Many factories roll-coat edges and bake them in conveyor ovens instead. A keeper loop and stitching finish it.","aka":["leather strap belt","dress belt"],"inputs":["leather","paint","thread","brass","steel"],"uses":[],"grounds":["cattle-hide","rock-salt","water","limestone","chromite","air","titanium-ore","iron-ore","sulfur","copper-ore","zinc-ore","lead-ore","tin-ore","crude-oil","coal","dolomite","manganese-ore","natural-gas","trona","bauxite","quartz","timber","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["leather","paint","thread","brass","steel","cattle-hide","rock-salt","water","lime","chromium","titanium-dioxide","pigment","acrylic","tin-can","polyester","copper","zinc","lead","tin","aluminum","pig-iron","magnesium","steel-scrap","oxygen","manganese","argon","limestone","chromite","coke","soda-ash","air","titanium-ore","chlorine","sulfuric-acid","iron-ore","carbon-black","sulfur","propylene","ammonia","methanol","tinplate","lacquer","ink","pet-plastic","copper-ore","zinc-ore","lead-ore","tin-ore","crude-oil","coal","petroleum-coke","alumina","dolomite","silicon","propane","manganese-ore","natural-gas","carbon-dioxide","trona","naphtha","ethanol","vegetable-oil","phenolic-resin","p-xylene","ethylene","ethylene-glycol","bauxite","caustic-soda","quartz","charcoal","timber","corn","yeast","hydrogen","sugarcane","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","molasses","benzene","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Inspect the hide","process":"inspect","text":"Belt leather arrives as full sides, inspected and then blocked for cutting. Full grain has the strongest fibers. Typical thickness runs 3.5 to 4.5 mm for men's belts and 2.8 to 3.5 mm for women's, and thin or overworked leather stretches for good.","inputs":["leather"]},{"name":"Cut the straps","process":"cut","text":"A strap cutter slices long strips from the side. Cuts must run clean and straight with the grain consistent, since off-grain or pieced sections weaken the finished strap.","inputs":[]},{"name":"Skive the buckle end","process":"machine","text":"A bench skiver removes about 20% of the strap's lower side at the buckle end, starting just before the second hole. The thinner end lets the buckle sit properly.","inputs":[]},{"name":"Bevel the corners","process":"machine","text":"Rotary cutting dials take the square corners off all four long edges. One shop sends each strap through twice, and the underside gets a slightly deeper cut than the top.","inputs":[]},{"name":"Punch the holes","process":"stamp","text":"A multi-hole cutting plate punches the row in one go. Holes must come out clean with no tearing, because this is where a strap takes the most stress and cracks first.","inputs":[]},{"name":"Dye and burnish edges","process":"coat","text":"Edge dye goes on twice and is burnished while tacky, which forces it into the fibers. Further passes use gum tragacanth, a plant-based smoothing agent. Painted edges look clean but can crack if the prep is poor.","inputs":["paint"]},{"name":"Condition the strap","process":"coat","text":"Saddle soap and heavy canvas clean and work the surface. Dry leather cracks faster, so skipping this saves time and costs durability.","inputs":[]},{"name":"Lockstitch the strap","process":"sew","text":"An industrial lockstitch machine sews the strap with even spacing, set tension and reinforced ends. The buckle sits on the thinned end. Buckles are usually brass or steel, bought in ready-made.","inputs":["thread","brass","steel"]},{"name":"Make the keeper","process":"assemble","text":"The small loop that holds back the free end gets nearly the same treatment as the strap: cut, dyed, beveled and smoothed, then stapled, stitched and molded. A blocker squares up its edges.","inputs":[]},{"name":"Brand and test","process":"inspect","text":"An electric brander marks the maker's name into the leather. Thorough checks flex the belt along its length, stress the holes and look at the edges after bending.","inputs":[]}],"facts":["Most belts have a keeper loop to stop the loose end from flapping, and many carry a metal tip on the end to protect it.","Chrome tanning, the method behind most modern leather, takes about a day, while one belt maker's vegetable-tanned hides take about 40 days.","Setting belt holes close together can stop owners drilling their own, which one maker blames for later cracks."],"where":[],"whereNote":null,"sources":[{"title":"21 Step Process, AZBelt","url":"https://azbelt.com/pages/21-step-process"},{"title":"How to Manufacture Leather Belts, Sourcify","url":"https://sourcify.com/blog/how-to-manufacture-leather-belts/"},{"title":"Belt (clothing)","url":"https://en.wikipedia.org/wiki/Belt_(clothing)"},{"title":"Leather","url":"https://en.wikipedia.org/wiki/Leather"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"winter-gloves","name":"Leather gloves","kind":"product","category":"textiles","title":"How leather gloves are made","url":"https://assemblyline.org/make/winter-gloves","stations":7,"upstream":40,"downstream":0,"depth":8,"dek":"A glove cutter squeezes about 11.5 inches of damp leather into a 9-inch length, so the glove stretches across the hand.","answer":"A leather glove starts as tanned skin that is dampened and stretched by hand. A cutter marks out the pair, and a hydraulic press stamps the shape on a hand-shaped metal frame. The thumb and the narrow strips between the fingers are sewn in. A silk, wool or cashmere lining is added last, and the glove is shaped on a heated hand form.","aka":["leather gloves","winter gloves","driving gloves"],"inputs":["leather","thread","silk","fleece"],"uses":[],"grounds":["fleece","cattle-hide","rock-salt","water","silk-cocoons","limestone","chromite","air","coal","trona","crude-oil","natural-gas","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["leather","thread","silk","fleece","cattle-hide","rock-salt","water","lime","chromium","polyester","silk-cocoons","hydrogen-peroxide","limestone","chromite","coke","soda-ash","air","aluminum","pet-plastic","hydrogen","coal","ammonia","carbon-dioxide","trona","crude-oil","petroleum-coke","alumina","p-xylene","ethylene","ethylene-glycol","natural-gas","corn","yeast","bauxite","caustic-soda","naphtha","oxygen","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Dampen and stretch the skin","process":"wash","text":"Skins are moistened to make them supple, then pulled along their length to refine the grain. A glover looks for flaws and works out where each glove will sit on the skin.","inputs":["leather"]},{"name":"Table-cut the blanks","process":"cut","text":"Cardboard patterns are laid on either side of the spine, and the leather is pulled by hand so about 11.5 inches goes into a 9-inch length. This makes the stretch in the finished glove run across the hand.","inputs":[],"spec":"11.5 in drawn to 9 in"},{"name":"Press out the shape","process":"stamp","text":"The blank is stamped onto a metal frame with sharpened edges by a hydraulic press. Each size has its own frame, with inserts for different styles.","inputs":[]},{"name":"Stitch the shell","process":"sew","text":"Any decoration on the back goes in first. The separate thumb, the three strips between the fingers called fourchettes and the small triangles called quirks are then joined on.","inputs":["thread"]},{"name":"Add the lining","process":"sew","text":"A winter glove gets a lining of silk, wool or cashmere, cut and stitched as its own glove and fixed inside the shell. With a lining, a pair can run to 52 pieces.","inputs":["silk","fleece"]},{"name":"Shape on a hand form","process":"press","text":"A small machine spreads the fingers to test the seams. The glove then goes on a heated hand form, which sets the leather and gives it its final shape.","inputs":[]},{"name":"Pair and pack","process":"package","text":"Gloves are paired by color and size, inspected and packed.","inputs":[]}],"facts":["Dents still sews on Singer machines so old that the only way to repair them is with parts from equally old models.","In 17th-century France, glove makers who also scented their leather with musk and ambergris became a recognized trade of their own."],"where":[],"whereNote":null,"sources":[{"title":"Glove","url":"https://en.wikipedia.org/wiki/Glove"},{"title":"Factory visit: Dents gloves (Permanent Style)","url":"https://www.permanentstyle.com/2011/01/factory-visit-dents-gloves.html"},{"title":"Savoir-faire (Maison Courtois Paris)","url":"https://courtoisparis.fr/en/pages/savoir-faire-gantier"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"handbag","name":"Leather handbag","kind":"product","category":"textiles","title":"How leather handbags are made","url":"https://assemblyline.org/make/handbag","stations":6,"upstream":67,"downstream":0,"depth":9,"dek":"Some leather bags are made from almost 100 separate pattern pieces, and each visible cut edge is painted by hand.","answer":"A leather handbag starts as tanned hides, which are checked for flaws and cut into flat panels with steel dies. The edges of the panels are thinned so seams do not bulk up. Stitching builds the bag from the inside out, linings go in, and metal hardware such as clasps and rings is riveted on.","aka":["leather bag","purse","tote"],"inputs":["leather","cotton-fabric","nylon","adhesive","thread","brass","zipper"],"uses":[],"grounds":["cattle-hide","rock-salt","water","limestone","chromite","air","raw-cotton","corn","natural-gas","crude-oil","copper-ore","zinc-ore","lead-ore","tin-ore","coal","trona","sulfur","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["leather","cotton-fabric","nylon","adhesive","thread","brass","zipper","cattle-hide","rock-salt","water","lime","chromium","cotton-yarn","corn-starch","benzene","nitric-acid","ammonia","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","polyester","copper","zinc","lead","tin","aluminum","limestone","chromite","coke","soda-ash","air","raw-cotton","corn","naphtha","hydrogen","toluene","natural-gas","ethylene","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","crude-oil","pet-plastic","copper-ore","oxygen","zinc-ore","lead-ore","tin-ore","coal","petroleum-coke","alumina","carbon-dioxide","trona","sulfur","p-xylene","ethylene-glycol","bauxite","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Inspect the hides","process":"inspect","text":"Each hide is examined for scars, insect bites and thin spots. Cutters plan which part of the hide goes into which piece, because the strongest and most even leather goes where the bag takes the strain.","inputs":["leather"]},{"name":"Die-cut the panels","process":"cut","text":"Cutters use a razor-sharp knife for one-off pieces and machines for regular shapes, working around scars and flaws. Lining pieces are cut from cotton, nylon or a lighter leather.","inputs":["cotton-fabric","nylon"]},{"name":"Skive and paint the edges","process":"machine","text":"A skiving knife shaves the edges of each panel thinner, so seams with several layers stay flat. Any cut edge that will show is stained, sealed and polished, either with a small wheel or by hand on tricky shapes.","inputs":[]},{"name":"Glue and reinforce","process":"laminate","text":"Stiffening and foam are glued behind the leather to give the bag its structure. Contact cement holds seam edges together so they can be stitched evenly.","inputs":["adhesive"]},{"name":"Stitch the bag","process":"sew","text":"Heavy-duty machines or craftspeople sew the panels together with waxed thread, usually in several passes. Handles and straps are stitched to the body with extra stitching at the stress points.","inputs":["thread"]},{"name":"Fix the hardware","process":"assemble","text":"Buckles, clasps, rings, rivets and zip pulls, which are cast or stamped from brass or steel, are riveted or screwed on. The lining is then closed, and the bag is stuffed with paper to hold its shape.","inputs":["brass","zipper"]}],"facts":["Tusting cuts only one thickness of hide at a time, so a hidden defect cannot slip through into a bag.","The oldest known surviving handbag is thought to be the Courtauld bag, made in Mosul in the early 1300s."],"where":[],"whereNote":null,"sources":[{"title":"Handbag","url":"https://en.wikipedia.org/wiki/Handbag"},{"title":"In the making (Tusting)","url":"https://tusting.co.uk/pages/in-the-making"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"leather-shoe","name":"Leather shoe","kind":"product","category":"textiles","title":"How leather shoes are made","url":"https://assemblyline.org/make/leather-shoe","stations":6,"upstream":61,"downstream":0,"depth":9,"dek":"Finer leather shoes still have their soles sewn on, a method that has been standard since the 17th century.","answer":"A leather shoe begins as pieces of leather cut to pattern and stitched into an upper. The upper is stretched over a wooden or plastic foot-form called a last, attached to an insole, then joined to an outsole by stitching or cement. A heel is added and the shoe is polished.","aka":["dress shoe","Oxford shoe","leather boot"],"inputs":["leather","thread","cardboard","rubber","adhesive"],"uses":[],"grounds":["cattle-hide","rock-salt","water","natural-latex","sulfur","limestone","chromite","air","timber","crude-oil","coal","trona","natural-gas","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["leather","thread","cardboard","rubber","adhesive","cattle-hide","rock-salt","water","lime","chromium","polyester","wood-pulp","natural-latex","synthetic-rubber","carbon-black","sulfur","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","limestone","chromite","coke","soda-ash","air","aluminum","pet-plastic","timber","caustic-soda","oxygen","hydrogen-peroxide","naphtha","benzene","ethylene","styrene","crude-oil","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","hydrogen","coal","carbon-dioxide","trona","petroleum-coke","alumina","p-xylene","ethylene-glycol","toluene","natural-gas","corn","yeast","bauxite","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the pattern pieces","process":"cut","text":"A die or knife cuts the vamp, quarters and lining out of leather, avoiding scars and weak spots in the hide.","inputs":["leather"]},{"name":"Stitch the upper","process":"sew","text":"Sewers join the pieces with heavy stitching to make the part of the shoe that covers the top of the foot, and add eyelets or hooks for the laces.","inputs":["thread"]},{"name":"Fit the insole board","process":"assemble","text":"An insole made of stiff paperboard or a synthetic nonwoven board forms the inside floor of the shoe. The edge of the upper is attached to it.","inputs":["cardboard"]},{"name":"Last the upper","process":"mold","text":"The upper is wrapped tight around a last, a foot-shaped form, and its bottom margin is pulled over the insole. The shoe takes its shape here.","inputs":[]},{"name":"Attach the sole","process":"assemble","text":"On finer shoes the outsole is stitched on, a method that has been standard since the 17th century. Cheaper shoes cement the sole in place with adhesive.","inputs":["rubber","adhesive"]},{"name":"Add the heel and finish","process":"assemble","text":"A heel is nailed or glued on, the edges are trimmed and the shoe is polished. A rubber heel plate adds traction.","inputs":[]}],"facts":["Marc Brunel developed machinery to mass-produce boots for the British Army during the Napoleonic Wars.","A rubber heel for boots and shoes was patented on January 24, 1899, by Humphrey O'Sullivan of Lowell, Massachusetts.","Shoe manufacturers in China account for 63 percent of world shoe production."],"where":[{"place":"China","share":"63 percent of world shoe production"}],"whereNote":"2007, share of world shoe production.","sources":[{"title":"Shoe","url":"https://en.wikipedia.org/wiki/Shoe"},{"title":"Leather","url":"https://en.wikipedia.org/wiki/Leather"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wallet","name":"Leather wallet","kind":"product","category":"textiles","title":"How leather wallets are made","url":"https://assemblyline.org/make/wallet","stations":10,"upstream":52,"downstream":0,"depth":8,"dek":"Each piece of wallet leather is split to a millimeter or less, or the finished stack would be far too thick.","answer":"A wallet holds more small parts than a handbag: inner and outer panels, linings, card slots, flaps, coin and bill pockets. At France's Ateliers Fourès, each is die-cut in a press, split to a millimeter or less, and thinned again at the edges so it can fold. Gluing and machine stitching then alternate, and the leather is rubbed to a shine.","aka":["billfold","bifold wallet","cardholder"],"inputs":["leather","adhesive","thread"],"uses":[],"grounds":["cattle-hide","rock-salt","water","limestone","chromite","air","crude-oil","coal","trona","natural-gas","sulfur","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["leather","adhesive","thread","cattle-hide","rock-salt","water","lime","chromium","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","polyester","limestone","chromite","coke","soda-ash","air","aluminum","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","pet-plastic","coal","carbon-dioxide","trona","petroleum-coke","alumina","naphtha","natural-gas","sulfur","benzene","p-xylene","ethylene-glycol","corn","yeast","bauxite","toluene","oxygen","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Die-cut the pieces","process":"cut","text":"Cutters read each skin for scars, insect bites and wrinkles, then place every part to dodge them or hide small flaws under a seam. A die in an arm press or bridge press stamps out the shape. Small parts are nested beside large ones, so only millimeters of scrap remain.","inputs":["leather"]},{"name":"Hot-stamp the logo","process":"press","text":"A heated stamp marks the brand on the leather. Each piece sits in a jig so the mark lands exactly in place.","inputs":[]},{"name":"Split to thickness","process":"machine","text":"Whole pieces are shaved thinner. Leather that arrives at about one and a half millimeters comes down to a millimeter or less for a wallet.","inputs":[]},{"name":"Pare the edges","process":"machine","text":"Now only the borders get thinned. A pared edge can fold over without building a thick ridge.","inputs":[]},{"name":"Fold the edges","process":"assemble","text":"Glue goes on the pared strip and the leather folds back on itself, leaving a clean, tough edge.","inputs":["adhesive"]},{"name":"Glue the parts","process":"assemble","text":"Leather, linings, reinforcements, card slots, flaps and zips are joined with glue or double-sided tape. So many small parts go into a wallet that this bench needs many assemblers.","inputs":["adhesive"]},{"name":"Machine-stitch the layers","process":"sew","text":"Assembled work goes to the sewing machines in batches, then often returns for more gluing and more stitching. A wallet's seams are short, so it takes fewer stitchers than a bag.","inputs":["thread"]},{"name":"Burn off thread ends","process":"cut","text":"Loose threads left by the machines are cut away with a hot-tipped tool.","inputs":[]},{"name":"Buff the surface","process":"grind","text":"A woolly sheepskin rubs the surface to a shine. On leather without a pigment coating, the heat and friction make small scratches disappear.","inputs":[]},{"name":"Label and box","process":"package","text":"Labels go on during a last quality check, and the wallet is boxed and wrapped.","inputs":[]}],"facts":["Before paper money, people kept coins in simple drawstring leather pouches.","Early wallets used cow or horse hide, with a little pocket for printed calling cards.","Leather is about 25% of the final cost of goods at one French workshop, which is why its cutters leave only millimeters of scrap."],"where":[],"whereNote":null,"sources":[{"title":"Craftsmanship, Ateliers Fourès","url":"https://ateliersfoures.fr/en/blogs/project/our-expertise"},{"title":"Wallet","url":"https://en.wikipedia.org/wiki/Wallet"},{"title":"Leather","url":"https://en.wikipedia.org/wiki/Leather"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"led","name":"LED","kind":"product","category":"electronics","title":"How LEDs are made","url":"https://assemblyline.org/make/led","stations":8,"upstream":24,"downstream":10,"depth":5,"dek":"A white LED is a blue light with a yellow phosphor on top, which is why it looks yellow when switched off.","answer":"Bright LEDs begin as a sapphire wafer inside a reactor, where metalorganic vapor lays down thin crystal films. Metal contacts are patterned on top, and the wafer is sawn or snapped into tiny dies. Each die is mounted and wired with gold. For white light, a blue die gets a yellow phosphor, which turns part of the blue light yellow.","aka":["light-emitting diode","white LED","LED chip"],"inputs":["gallium","indium","ammonia","hydrogen","gold","plastic"],"uses":["led-bulb","lcd-screen","television","computer-mouse","pinball-machine","e-reader","remote-control"],"grounds":["bauxite","zinc-ore","natural-gas","water","air","gold-ore","rock-salt","sulfur","limestone","crude-oil"],"upstreamSlugs":["gallium","indium","ammonia","hydrogen","gold","plastic","bauxite","caustic-soda","zinc-ore","sulfuric-acid","natural-gas","water","air","gold-ore","lime","zinc","chlorine","naphtha","ethylene","propylene","rock-salt","sulfur","limestone","crude-oil"],"downstreamSlugs":["led-bulb","lcd-screen","television","computer-mouse","pinball-machine","e-reader","remote-control","laptop","smartwatch","digital-camera"],"steps":[{"name":"Grow crystal layers from gas","process":"grow","inputs":["gallium","indium","ammonia","hydrogen"],"text":"A sapphire wafer rests on a heated holder called a susceptor while a carrier gas brings metalorganic molecules across it. They react on the surface and build single-crystal films layer by layer. For blue and green LEDs the film is indium gallium nitride."},{"name":"Pattern the contacts","process":"etch","inputs":[],"text":"Liquid photoresist is dripped on the spinning wafer and hardened. Ultraviolet light through a mask copies the contact pattern onto it, and a developer washes the exposed areas away."},{"name":"Evaporate on metal","process":"deposit","inputs":[],"text":"In a vacuum chamber, a chunk of metal is heated until it vaporizes and condenses on the open areas of the wafer, the way steam fogs a cold window. Solvent lifts off the resist, and a furnace bonds metal to crystal so it will not flake."},{"name":"Cut out the dies","process":"cut","inputs":[],"text":"The wafer is snapped along a crystal plane or sawn with a diamond blade. This step is hard and error prone, and it costs far more dies than the pattern promises.","spec":"up to 6,000 on a 2-inch wafer"},{"name":"Mount and wire","process":"assemble","inputs":["gold"],"text":"Each die goes onto its package, its metal back touching one lead. A tiny gold wire runs from the other lead to the top contact, pressed on with a fine needle so the soft gold deforms and sticks."},{"name":"Coat with yellow phosphor","process":"coat","inputs":[],"text":"For white light, a blue die is covered with cerium-doped yttrium aluminium garnet crystals suspended in the package. Some blue light passes through and some turns yellow, and the mix looks white."},{"name":"Seal in plastic","process":"mold","inputs":["plastic"],"text":"The die and wires sit in a mold while clear plastic seals around them. The plastic's shape and tint decide whether the light scatters or leaves in a narrow beam."},{"name":"Test brightness and color","process":"inspect","inputs":[],"text":"Every LED is checked to see that a set current gives the right brightness. Color is tested batch by batch, and some units go off for lifetime, heat and damage tests."}],"facts":["The first white LEDs went on sale in autumn 1996, and the cerium-doped garnet phosphor they use is itself grown with the Czochralski method.","Green LEDs could in theory reach 683 lumens per watt, yet in 2010 few exceeded 100."],"where":[],"whereNote":null,"sources":[{"title":"Light-Emitting Diode (LED) (How Products Are Made)","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/light-emitting-diode-led"},{"title":"Brighter and cheaper LEDs thanks to better semiconductor processing equipment","url":"https://machinedesign.com/community/article/21819116/brighter-and-cheaper-leds-thanks-to-better-semiconductor-processing-equipment"},{"title":"Light-emitting diode","url":"https://en.wikipedia.org/wiki/Light-emitting_diode"},{"title":"Metalorganic vapour-phase epitaxy","url":"https://en.wikipedia.org/wiki/Metalorganic_vapour-phase_epitaxy"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"led-bulb","name":"LED light bulb","kind":"product","category":"electronics","title":"How LED light bulbs are made","url":"https://assemblyline.org/make/led-bulb","stations":7,"upstream":67,"downstream":0,"depth":9,"dek":"An LED bulb needs a power supply inside the base and an aluminum back to carry away the heat.","answer":"LED bulbs are built more like electronics than lamps. Solder paste goes on an aluminum circuit board, machines place the LEDs and chips at high speed, and a reflow oven melts the solder. The boards snap apart and go to a line that glues them into bases, attaches cords and covers, and tests each bulb's light twice.","aka":["LED lamp","LED light","LED globe"],"inputs":["led","printed-circuit-board","aluminum","solder","adhesive","polycarbonate"],"uses":[],"grounds":["crude-oil","coal","water","bauxite","zinc-ore","natural-gas","air","gold-ore","copper-ore","silica-sand","limestone","tin-ore","lead-ore","silver-ore","rock-salt","sulfur","trona","corn","sugarcane","sugar-beet"],"upstreamSlugs":["led","printed-circuit-board","aluminum","solder","adhesive","polycarbonate","gallium","indium","ammonia","hydrogen","gold","plastic","copper","fiberglass","epoxy","photoresist","crude-oil","coal","petroleum-coke","alumina","tin","lead","silver","polyethylene","acrylic","polyurethane","paraffin-wax","water","phenol","propylene","acetone","caustic-soda","chlorine","bauxite","zinc-ore","sulfuric-acid","natural-gas","air","gold-ore","lime","zinc","naphtha","ethylene","copper-ore","oxygen","silica-sand","limestone","soda-ash","phenolic-resin","tin-ore","coke","lead-ore","silver-ore","methanol","nitric-acid","benzene","rock-salt","sulfur","carbon-dioxide","trona","formaldehyde","toluene","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Place chips by machine","process":"assemble","text":"Boards are thin aluminum sheets that act as heat sinks, coated with an insulator and copper traces. After solder paste goes on, surface-mount machines place LEDs and driver chips at very high speed, working on large panels that hold many circles.","inputs":["led","printed-circuit-board","aluminum","solder"]},{"name":"Melt the solder","process":"heat-treat","text":"The panels pass through a reflow oven, a hot air furnace that melts the paste. They then snap apart like cupcakes from a tray, and power wires are soldered on by hand.","inputs":[]},{"name":"Build the driver","process":"assemble","text":"The small power supply goes through surface-mount machines too, then along a row of workers adding one large component at a time. Some factories buy it in from elsewhere.","inputs":["printed-circuit-board"]},{"name":"Glue into bases","process":"assemble","text":"Workers mark the bases and load them onto a conveyor to a gluing stage. Modules are pressed in tight so heat flows into the base.","inputs":["adhesive","aluminum"]},{"name":"Attach cords and cover","process":"assemble","text":"AC cords are fixed and automatically straightened. With the cover on, each lamp faces its first automatic lighting check.","inputs":["polycarbonate"]},{"name":"Rivet the cap","process":"assemble","text":"Lamps that light have their extra cord cut and riveted to the cap, then the cover is glued and pressed on.","inputs":[]},{"name":"Test and pack","process":"inspect","text":"A second lighting check removes any failures to repair. Passing lamps get a printed date, an appearance check and an automatic pack. A blower at the end sends any unpacked lamp back to the start of packing.","inputs":[]}],"facts":["The most efficient commercial LED lamps exceed 200 lumens per watt, while incandescent lamps manage only 10 to 17.","Lighting consumes roughly 12% of electrical energy produced by industrialized countries."],"where":[],"whereNote":null,"sources":[{"title":"PCSTATS: Ever wonder how an LED light bulb is made?","url":"https://www.pcstats.com/articles/2423/index.html"},{"title":"Rang Dong: LED bulb production line","url":"https://en.rangdong.com.vn/news/led-bulb-production-line-a-state-of-the-art-production-line-of-rang-dong-factory"},{"title":"LED lamp","url":"https://en.wikipedia.org/wiki/LED_lamp"},{"title":"Light-emitting diode","url":"https://en.wikipedia.org/wiki/Light-emitting_diode"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"leggings","name":"Leggings","kind":"product","category":"textiles","title":"How leggings are made","url":"https://assemblyline.org/make/leggings","stations":8,"upstream":35,"downstream":0,"depth":8,"dek":"Leggings fabric has to rest before anyone cuts it, because knitting and rolling leave it under tension.","answer":"Leggings are knit from nylon or polyester yarn blended with spandex, a polyurethane fiber that stretches far and snaps back. The knit tube is dyed, cut in mirror-image leg panels, and sewn with stretch seams. Elastic is stitched into the waistband, and the garment is pressed, checked and folded.","aka":["tights","yoga pants","running tights"],"inputs":["polyurethane","nylon","polyester","spandex","thread"],"uses":[],"grounds":["water","crude-oil","air","rock-salt","natural-gas","sulfur","coal","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["polyurethane","nylon","polyester","spandex","thread","propylene","nitric-acid","chlorine","water","benzene","ammonia","pet-plastic","formaldehyde","ethylene-glycol","naphtha","crude-oil","air","rock-salt","sulfuric-acid","hydrogen","toluene","natural-gas","p-xylene","ethylene","methanol","oxygen","carbon-dioxide","sulfur","coal","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Make the stretch fiber","process":"react","text":"Spandex is made from a polyurethane formed by reacting a diol with a diisocyanate. The polymer is then dissolved and drawn out through tiny holes into a fine, very elastic filament.","inputs":["polyurethane"]},{"name":"Combine with nylon or polyester","process":"spin","text":"The spandex core is wrapped or twisted together with a harder fiber. The nylon or polyester gives the cloth its look and its strength, and the spandex gives the stretch.","inputs":["nylon","polyester","spandex"]},{"name":"Knit the tube","process":"weave","text":"A circular knitting loom loops the blended yarn into a tube of weft-knit fabric. The tight, smooth knit is what gives leggings their sleek surface.","inputs":[]},{"name":"Dye in a hot bath","process":"dye","text":"The fabric is dyed in a hot bath and then dried. Synthetic fibers take dye under heat.","inputs":[]},{"name":"Inspect and relax the rolls","process":"inspect","text":"Rolls are checked for flaws and left to relax. High-stretch cloth stays under tension from knitting, dyeing and rolling, and cutting it straight off the roll gives panels that shrink out of size later.","inputs":[]},{"name":"Cut the leg panels","process":"cut","text":"Cutters cut left and right leg panels and a waist piece from spread layers. The cut pieces have to mirror each other or the finished leg will twist.","inputs":[]},{"name":"Sew with stretch stitches","process":"sew","text":"Flatlock or overlock machines close the inner and outer leg seams and the seat. These stitches are loops, so they stretch with the cloth instead of snapping.","inputs":["thread"]},{"name":"Fit the waistband","process":"assemble","text":"A wide band of fabric is folded and stitched around the top, with reinforcement where it takes strain. The finished pairs are inspected, pressed and folded.","inputs":[]}],"facts":["Spandex, invented by DuPont chemist Joseph Shivers in 1958, can stretch up to five times its length.","Spandex fibers cannot be melted and spun like most synthetic fibers, because the polymer breaks down when it melts."],"where":[],"whereNote":null,"sources":[{"title":"Leggings","url":"https://en.wikipedia.org/wiki/Leggings"},{"title":"Elastane","url":"https://en.wikipedia.org/wiki/Elastane"},{"title":"How yoga wear is made (Wonderx)","url":"https://www.wonderxfans.com/it/blogs/notizia/how-yoga-wear-is-made"},{"title":"Where does our performance fabric come from (Art of Where)","url":"https://blog.artofwhere.com/where-does-our-performance-fabric-come-from/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lego-brick","name":"LEGO brick","kind":"product","category":"plastics","title":"How LEGO bricks are made","url":"https://assemblyline.org/make/lego-brick","stations":6,"upstream":25,"downstream":0,"depth":7,"dek":"LEGO makes roughly 36 billion bricks a year, or about 1140 pieces every second.","answer":"LEGO bricks are made of ABS plastic. Colored granules are dried and melted, then injected into steel molds under very high pressure. The mold cools the plastic into a finished brick in seconds, and the brick drops out. Bricks are checked against a standard and packed into boxes for sets.","aka":["LEGO","toy brick","interlocking brick"],"inputs":["abs-plastic","pigment"],"uses":[],"grounds":["air","iron-ore","sulfur","crude-oil","water","natural-gas","titanium-ore","coal","rock-salt"],"upstreamSlugs":["abs-plastic","pigment","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","iron-ore","titanium-dioxide","carbon-black","sulfur","crude-oil","water","hydrogen","natural-gas","toluene","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","coal","rock-salt"],"downstreamSlugs":[],"steps":[{"name":"Color and dry the granules","process":"mix","text":"ABS granules are blended with color pigment and dried. Each color is stored in its own silo so that shades never mix.","inputs":["abs-plastic","pigment"]},{"name":"Melt it in the barrel","process":"melt","text":"A screw inside a heated barrel melts the granules. It pushes the soft plastic forward toward the mold.","inputs":[]},{"name":"Inject it into a steel mold","process":"mold","text":"The molten plastic is forced into a cavity machined to precise dimensions. The tight fit of a brick on its neighbors depends on the mold being exact.","inputs":[]},{"name":"Cool and eject the bricks","process":"chill","text":"Water channels in the mold chill the plastic until it holds its shape. The mold opens and the finished bricks drop into a bin.","inputs":[]},{"name":"Check a sample","process":"inspect","text":"Bricks are tested for fit and clutch, which is how firmly they snap together and come apart. Any that fail are discarded and ground up for reuse.","inputs":[]},{"name":"Pack into set boxes","process":"package","text":"Machines count out the right bricks for each set and seal them in bags. The bags go into boxes with instructions.","inputs":[]}],"facts":["The machines that make Lego bricks hold tolerances as small as 10 micrometers.","By July 2015, 600 billion LEGO parts had been produced.","LEGO began making interlocking bricks in 1949, inspired by the self-locking bricks invented by English toymaker Hilary Page in 1939."],"where":[],"whereNote":null,"sources":[{"title":"Lego","url":"https://en.wikipedia.org/wiki/Lego"},{"title":"Acrylonitrile butadiene styrene","url":"https://en.wikipedia.org/wiki/Acrylonitrile_butadiene_styrene"},{"title":"Injection moulding","url":"https://en.wikipedia.org/wiki/Injection_moulding"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"licorice","name":"Licorice","kind":"product","category":"food","title":"How licorice candy is made","url":"https://assemblyline.org/make/licorice","stations":6,"upstream":27,"downstream":0,"depth":9,"dek":"The main sweet compound in licorice root is about 30 to 50 times sweeter than sugar, and some candy uses little of it.","answer":"Licorice candy starts with a dark extract from the root of the licorice plant. The extract is dissolved with sugar, a starch or flour base and often molasses, and the whole mix is cooked at 135 degrees Celsius. It is poured into molds pressed into trays of starch powder, dried and sprayed with beeswax so it shines.","aka":["liquorice","black licorice","liquorice sweets"],"inputs":["sugar","flour","molasses","water","beeswax"],"uses":[],"grounds":["water","sugarcane","sugar-beet","wheat","honeycomb","limestone","air","corn","natural-gas","crude-oil"],"upstreamSlugs":["sugar","flour","molasses","water","beeswax","sugarcane","sugar-beet","lime","wheat","vitamin-c","honeycomb","limestone","corn-starch","hydrogen","air","plastic-bottle","corn","natural-gas","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","crude-oil","yeast"],"downstreamSlugs":[],"steps":[{"name":"Dig up the roots","process":"harvest","text":"The licorice plant is a legume with a long sweet root. It is harvested in autumn, two to three years after planting, in places such as Turkey, Greece, Iran and Iraq.","inputs":[]},{"name":"Draw out the sweet extract","process":"refine","text":"The sweet, aromatic part of the root is pulled out as a concentrated dark extract. The main sweet compound is glycyrrhizin, and its flavor builds slowly and lingers longer than sugar does.","inputs":[]},{"name":"Cook the candy mass","process":"cook","text":"Extract, sugar, a binder of starch or flour and often molasses are dissolved in water and heated to 135 degrees Celsius. The binder is what turns a syrup into a chewy sweet.","inputs":["sugar","flour","molasses","water"],"spec":"135 °C"},{"name":"Pour into starch molds","process":"cast","text":"Holes are pressed into a tray of starch powder and the hot liquid is poured into them. The powder soaks up surface moisture and holds the shape until the candy sets, and is sifted off and used again. Common ropes and twists are extruded instead.","inputs":[]},{"name":"Dry the pieces","process":"dry","text":"The poured candy dries in its molds until it can be handled. The pieces are then lifted out of the powder.","inputs":[]},{"name":"Spray with wax","process":"coat","text":"A light spray of beeswax gives the surface a shine and keeps the pieces from sticking together.","inputs":["beeswax"]}],"facts":["In most licorice-flavored candy the taste is boosted with aniseed oil, so the actual licorice content is low.","In the Netherlands, salty licorice is made with ammonium chloride and sold as zoute drop.","The word licorice comes from the Greek for sweet root."],"where":[],"whereNote":null,"sources":[{"title":"Liquorice","url":"https://en.wikipedia.org/wiki/Liquorice"},{"title":"Liquorice (confectionery)","url":"https://en.wikipedia.org/wiki/Licorice_(confectionery)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"light-beer","name":"Light beer","kind":"product","category":"drink","title":"How light beer is made","url":"https://assemblyline.org/make/light-beer","stations":6,"upstream":54,"downstream":0,"depth":9,"dek":"An added enzyme lets yeast eat starch fragments it normally leaves, cutting carbs from about 14 grams to under 3.","answer":"Light beer is brewed like regular beer, but the brewer reduces the starch fragments called dextrins that give beer about a third of its calories. An enzyme, a longer mash or part-replacement of malt with corn syrup does it. Carbohydrates can fall from about 14 grams to under 3 per 12-ounce serving.","aka":["lite beer","low-calorie beer"],"inputs":["barley","water","malted-barley","hops","corn-syrup","yeast","carbon-dioxide","aluminum-can"],"uses":[],"grounds":["barley","water","hops","corn","natural-gas","limestone","sugarcane","sugar-beet","crude-oil","coal","bauxite","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","rock-salt"],"upstreamSlugs":["barley","water","malted-barley","hops","corn-syrup","yeast","carbon-dioxide","aluminum-can","corn","corn-starch","molasses","natural-gas","limestone","aluminum","ink","epoxy","sugarcane","sugar-beet","crude-oil","coal","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","phenol","propylene","acetone","chlorine","caustic-soda","bauxite","lime","soybeans","rapeseed","hexane","clay","formaldehyde","air","titanium-ore","coke","oxygen","sulfuric-acid","iron-ore","sulfur","ethylene","benzene","naphtha","rock-salt","hydrogen","methanol","toluene"],"downstreamSlugs":[],"steps":[{"name":"Mash the grain","process":"mix","text":"Malted barley is soaked in hot water to turn its starch to sugar, making a sweet liquid called wort. Some light-beer makers use high-enzyme barley malt and a longer mash to convert more starch.","inputs":["barley","water","malted-barley"]},{"name":"Boil with hops","process":"cook","text":"The wort is boiled for roughly one to two hours with hops, which adds bitterness and aroma. Some brewers replace part of the malt with corn syrup, which leaves fewer dextrins behind.","inputs":["hops","corn-syrup"]},{"name":"Break down the dextrins","process":"react","text":"The enzyme amyloglucosidase goes into the cooled wort. It turns dextrins, starch fragments yeast cannot normally eat, into fermentable sugar.","inputs":[]},{"name":"Ferment with yeast","process":"ferment","text":"Yeast eats the sugar for around ten days, turning it into alcohol and carbon dioxide. With more sugar available the beer comes out stronger than the finished product should be.","inputs":["yeast"]},{"name":"Dilute and carbonate","process":"mix","text":"Brewers add carbonated water to bring the alcohol back down. The beer is conditioned and filtered a last time before packaging.","inputs":["water","carbon-dioxide"]},{"name":"Can or keg it","process":"fill","text":"The finished beer is filled into cans, bottles or kegs.","inputs":["aluminum-can"]}],"facts":["Dr. Hersch Gablinger applied for patents on his amyloglucosidase process in Switzerland in 1964, and the United States granted his in 1968.","Miller Lite was not marketed nationally in the United States until 1975.","In Australia, Canada and the United Kingdom, light beer means lower alcohol, not lower calories."],"where":[],"whereNote":null,"sources":[{"title":"Light beer","url":"https://en.wikipedia.org/wiki/Light_beer"},{"title":"Beer","url":"https://en.wikipedia.org/wiki/Beer"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"light-switch","name":"Light switch","kind":"product","category":"electronics","title":"How light switches are made","url":"https://assemblyline.org/make/light-switch","stations":8,"upstream":85,"downstream":0,"depth":10,"dek":"The quick-break switch, invented in 1884, snaps the contacts apart so they do not burn.","answer":"Presses stamp copper or brass into contacts, terminals and spring parts. Hot plastic is molded around metal inserts to make one solid body. Assembly machines feed parts, lock screws and test force as they go, and finished switches are checked for contact resistance and insulation, with life tests that flip them thousands of times.","aka":["wall switch","toggle switch"],"inputs":["brass","copper","silver","steel-wire","plastic","screw","cardboard-box"],"uses":[],"grounds":["copper-ore","water","air","silver-ore","lead-ore","zinc-ore","natural-gas","tin-ore","crude-oil","coal","sulfur","limestone","bauxite","iron-ore","dolomite","manganese-ore","timber","soybeans","rapeseed","clay","titanium-ore","corn","sugarcane","rock-salt","quartz","sugar-beet"],"upstreamSlugs":["brass","copper","silver","steel-wire","plastic","screw","cardboard-box","zinc","lead","tin","aluminum","copper-ore","water","oxygen","air","sulfuric-acid","silver-ore","lead-ore","zinc-ore","lime","steel","naphtha","natural-gas","ethylene","propylene","cardboard","ink","adhesive","coke","tin-ore","crude-oil","coal","petroleum-coke","alumina","sulfur","limestone","pig-iron","magnesium","steel-scrap","manganese","argon","hydrogen","wood-pulp","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","bauxite","caustic-soda","iron-ore","dolomite","silicon","propane","manganese-ore","timber","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","titanium-ore","chlorine","corn","sugarcane","yeast","ammonia","methanol","acetone","nitric-acid","rock-salt","quartz","charcoal","benzene","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Stamp the contacts","process":"stamp","text":"High-speed presses punch and bend copper or brass sheet through a continuous die to make contacts and terminals. One stamping supplier holds errors to within 0.01 to 0.05 millimeters, so parts touch tightly and do not arc or overheat.","inputs":["brass","copper"]},{"name":"Rivet the silver points","process":"assemble","text":"A plug and socket maker in Wenzhou, China, adds silver contact points with automatic welding and riveting. Integrated dies can punch, bend and rivet a part in one run.","inputs":["silver"]},{"name":"Form the spring","process":"press","text":"A spring is formed that sets the feel of the flip and, in a quick-break design, snaps the contacts apart.","inputs":["steel-wire"]},{"name":"Mold the body","process":"mold","text":"Hot flame-retardant plastic flows into a mold around metal pieces and cools into one strong part. At the Wenzhou plant, five-axis robot arms place the copper inserts and chilled water cools the work.","inputs":["plastic"]},{"name":"Assemble the mechanism","process":"assemble","text":"Parts go together on a line where machines feed pieces, lock screws, test force and run high-pressure checks while skilled workers watch. One company reports working 30% faster with automated assembly.","inputs":["screw"]},{"name":"Check function and contacts","process":"inspect","text":"Inspectors measure incoming parts and coating thickness, adjust molds and tools during assembly, then test each finished switch for function and contact resistance.","inputs":[]},{"name":"Flip it thousands of times","process":"inspect","text":"Life testing flips the switch thousands of times. Other tests cycle its load and temperature, expose it to humid air and check insulation resistance before shipping.","inputs":[]},{"name":"Pack for shipping","process":"package","text":"Blister packs or plastic trays keep switches apart, and antistatic materials protect inner parts on the way to the store.","inputs":["cardboard-box"]}],"facts":["John Henry Holmes invented the first quick-break light switch in 1884 in Newcastle upon Tyne.","The quick-break design fixed the problem of contacts burning from arcing as they slowly came apart.","William J. Newton invented the toggle light switch in 1916."],"where":[],"whereNote":null,"sources":[{"title":"Light switch","url":"https://en.wikipedia.org/wiki/Light_switch"},{"title":"Injection molding","url":"https://en.wikipedia.org/wiki/Injection_moulding"},{"title":"Wall Switch Basics: Easy Guide to How They're Made","url":"https://www.onesto-ep.com/blog/wall-switch-basics-easy-guide-to-how-theyre-made/"},{"title":"Analysis of Switch Socket Precision Custom Metal Stamping Parts","url":"https://www.stamping-welding.com/info/analysis-of-switch-socket-precision-custom-met-103532547.html"},{"title":"Stamping Riveting Electrical Copper Press Parts For Switch Sockets","url":"https://www.china-electronic-components.com/news/stamping-riveting-electrical-copper-press-part-85540537.html"},{"title":"Factory Show & Manufacturing Capacity (Kripal)","url":"https://www.kripal.net/?p=163"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"limestone","name":"Limestone","kind":"raw","category":"ground","title":"How limestone is quarried","url":"https://assemblyline.org/make/limestone","stations":3,"upstream":0,"downstream":447,"depth":0,"dek":"A quarter of all sedimentary rock is carbonate, and the white filler in toothpaste is often ground limestone.","answer":"Limestone is a rock made mostly of calcium carbonate that settled out of water, often with help from shells and corals. Quarries drill holes in the rock face, blast it into pieces and crush it to size. The crushed stone becomes road base, cement and the lime used in steelmaking and agriculture.","aka":["calcium carbonate rock","carbonate rock"],"inputs":[],"uses":["toothpaste","lime","soda-ash","fiberglass","pig-iron","chromium","glass","window-glass","glass-bottle","cement","marble-toy","baking-soda","chewing-gum","carbon-dioxide","roof-shingle","vinyl-floor","stained-glass","paper"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["toothpaste","lime","soda-ash","fiberglass","pig-iron","chromium","glass","window-glass","glass-bottle","cement","marble-toy","baking-soda","chewing-gum","carbon-dioxide","roof-shingle","vinyl-floor","stained-glass","paper","steel","alumina","gold","silver","sugar","gelatin","tortilla","wood-pulp","leather","detergent","lithium-carbonate","smartphone-glass","instant-noodles","vanadium","printed-circuit-board","wind-turbine","surfboard","ski","snowboard","fishing-rod","kite","canoe","sailboat","umbrella","cast-iron-pan","car-engine","piano","dumbbell","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","stent","wrench","nichrome","thermometer","lcd-screen","oled-screen","camera-sensor","solar-panel","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","floor-tile","neon-sign","smartwatch","e-reader","mirror","skyscraper","windshield","double-glazed-window","nail-polish","perfume","penicillin","insulin","vaccine","ketchup","cola","sparkling-water","beer","wine","champagne","whiskey","vodka","gin","rum","tequila","sake","hard-cider","hot-sauce","soda","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","port-wine","prosecco","non-alcoholic-beer","washing-machine","concrete","pretzel","frozen-pizza","bagel","crackers","cake-mix","fire-extinguisher","aspirin","fertilizer","decaf-coffee","refrigerant","popping-candy","energy-drink","light-beer","caffeine","melamine-resin","ethylene-glycol","soap","adhesive-bandage","aa-battery","vacuum-cleaner","drywall","popcorn","crayon","fireworks","plastic-straw","paper-straw","paper-cup","paper-bag","pizza-box","egg-carton","wallpaper","laminate-floor","board-game","jigsaw-puzzle","tampon","sanitary-pad","cotton-swab","loudspeaker","vinyl-record","compact-disc","inkjet-printer","newspaper","book","envelope","sticky-notes","playing-cards","toothbrush","lithium-ion-cell","ev-battery","television","electric-motor","transformer","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","golf-club","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","drill-bit","gas-cylinder","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","electric-toothbrush","aluminum","microchip","led","needle","gold-ring","fountain-pen","gold-bar","medal","smoke-detector","solar-cell","solder","coin","trumpet","thermos","flute","light-switch","vitamin-c","brown-sugar","yogurt","ice-cream","mayonnaise","peanut-butter","croissant","donut","sandwich-cookie","corn-flakes","bacon","chocolate","gummy-bears","marshmallow","jelly-beans","candy-cane","cotton-candy","sprinkles","condensed-milk","pickles","kimchi","jam","hazelnut-spread","imitation-crab","salami","ham","beef-jerky","canned-meat","white-chocolate","caramel-color","candy-coated-chocolate","licorice","caramel","lollipop","toffee","gelatin-dessert","cough-syrup","gelatin-capsule","banknote","kitchen-sponge","cellulose-acetate","cardboard","toilet-paper","facial-tissue","rayon","diaper","baseball","basketball","tennis-racket","football","winter-gloves","handbag","wallet","hiking-boots","digital-camera","leather-shoe","smartphone","hearing-aid","pacemaker","led-bulb","laptop","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","car","electric-car","airbag","rocket","blender","ceiling-fan","treadmill","pinball-machine","wireless-earbuds","phone-charger","game-console","wifi-router","graphics-card","remote-control","syringe","electric-kettle","kitchen-knife","fork","water-bottle","pressure-cooker","asthma-inhaler","jet-engine","mustard","salsa","sauerkraut","aluminum-window-frame","shampoo","deodorant","air-freshener","dish-soap","hairspray","foundation-makeup","refrigerator","air-conditioner","pet-plastic","spandex","hinge","saw-blade","shovel","wheelbarrow","brake-pad","tin-can","canned-tuna","wire-rope","nail","screw","paperclip","tire","guitar","electric-guitar","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","suspension-bridge-cable","mattress","roller-skates","lipstick","pencil","aluminum-foil","brass","cobalt","nonstick-pan","aluminum-can","pencil-eraser","eyeshadow","prosthetic-leg","ladder","microphone","camera-lens","zipper","n95-mask","credit-card","flour","dice","shoelace","duct-tape","plastic-wrap","clear-tape","trading-cards","hair-dye","cardboard-box","match","polyester","plastic-bottle","3d-printer-filament","bottled-water","underwear","leggings","swimsuit","paint","baby-formula","coconut-milk","canned-soup","action-figure","power-outlet","condom","garden-hose","key","flag","tungsten-carbide","insect-repellent","down-jacket","raincoat","backpack","jeans","bread","chicken-nuggets","baguette","sourdough","fish-sticks","modeling-clay","plastic-bag","nitrile-glove","candle","zip-bag","pillow","mouthwash","soccer-ball","marker-pen","highlighter","volleyball","wet-wipes","hoodie","curtain","sneaker","button","thread","teddy-bear","sunscreen","bleach","golf-ball","wooden-chair","billiard-ball","fashion-doll","dress-shirt","suit","baseball-cap","bike-helmet","silk-tie","felt-hat","blanket","t-shirt","socks","sweater","towel"],"steps":[{"name":"Drill the quarry face","process":"mine","text":"Holes are drilled into the rock and loaded with explosives. Limestone is normally worked in open quarries, one bench at a time.","inputs":[]},{"name":"Blast it loose","process":"mine","text":"A controlled blast cracks the face into truck-sized blocks and smaller pieces. Loaders scoop the broken rock and haul it to the crusher.","inputs":[]},{"name":"Crush and sort","process":"crush","text":"Jaw and cone crushers reduce the rock in stages, and screens sort the pieces into sizes. Large pieces go on to a kiln for lime or cement, and smaller grades are sold as aggregate.","inputs":[]}],"facts":["Limestone is mostly calcite and aragonite, two crystal forms of calcium carbonate.","Ground fine, it is the white pigment or filler in toothpaste and paint.","It is also an additive in glass making, paper and plastics."],"where":[],"whereNote":null,"sources":[{"title":"Limestone","url":"https://en.wikipedia.org/wiki/Limestone"},{"title":"Quarry","url":"https://en.wikipedia.org/wiki/Quarry"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"linen","name":"Linen","kind":"material","category":"textiles","title":"How linen is made","url":"https://assemblyline.org/make/linen","stations":6,"upstream":2,"downstream":0,"depth":1,"dek":"Linen comes from flax stems that are left to rot on purpose so the fibers inside come loose.","answer":"Linen is cloth made from the inner bast fibers of the flax plant. Farmers pull or cut the stalks near the root, strip the seeds, then ret them, letting bacteria rot the glue that binds the fibers. The dried stalks are crushed and combed, leaving long fibers that are spun into yarn and woven.","aka":["flax cloth","Irish linen","flax fabric"],"inputs":["flax","water"],"uses":[],"grounds":["flax","water"],"upstreamSlugs":["flax","water"],"downstreamSlugs":[],"steps":[{"name":"Pull the flax","process":"harvest","text":"To get the longest fibers, flax is pulled up whole or cut very close to the root. The stalks are dried, and a threshing step called rippling removes the seeds.","inputs":["flax"]},{"name":"Rot the stalks loose","process":"ferment","text":"In retting, bacteria decompose the pectin that glues the fibers to the woody core. It happens in tanks or pools, or straight in the field. Chemical retting is faster but harsher on the fibers and the environment.","inputs":["water"]},{"name":"Crush the woody core","process":"crush","text":"In scutching, the retted stalks are crushed between metal rollers so the woody part breaks away from the fibers. Seeds, shives and tow are set aside for other uses.","inputs":[]},{"name":"Comb out the short fibers","process":"separate","text":"Heckling combs pull the short fibers away and leave only the long, soft flax fibers, which range from about 25 to 150 mm.","inputs":[]},{"name":"Spin into yarn","process":"spin","text":"The long fibers are drawn and twisted into yarn. Fine linen yarns for handkerchiefs are much lighter per yard than coarse ones.","inputs":[]},{"name":"Weave or knit","process":"weave","text":"The yarn is woven or knitted into cloth, which can then be bleached, dyed, printed on or finished.","inputs":[]}],"facts":["Dyed flax fibers found in a cave in the Caucasus suggest that humans may have used woven linen over 30,000 years ago.","United States currency paper is 25 percent linen and 75 percent cotton.","At one time Russia produced about 80 percent of the world's fiber flax crop."],"where":[{"place":"China","share":"$732.3 million of woven linen fabric exported"},{"place":"Italy","share":"$173.0 million exported"},{"place":"Belgium","share":"$68.9 million exported"},{"place":"United Kingdom","share":"$51.7 million exported"}],"whereNote":"2018, value of woven linen fabric exports, from United Nations trade statistics.","sources":[{"title":"Linen","url":"https://en.wikipedia.org/wiki/Linen"},{"title":"Spinning (textiles)","url":"https://en.wikipedia.org/wiki/Spinning_(textiles)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"linseed-oil","name":"Linseed oil","kind":"material","category":"chemicals","title":"How linseed oil is made","url":"https://assemblyline.org/make/linseed-oil","stations":7,"upstream":1,"downstream":1,"depth":1,"dek":"A pile of rags soaked in this oil can catch fire by itself, because it warms up as it hardens in air.","answer":"Flaxseed holds 38 to 45 percent oil. Mills often cook the seed to rupture its cells, then squeeze it in an expeller press, while food oil is cold pressed raw. Industrial plants soak pre-pressed seed in hexane to dissolve out the rest. Refining strips gums and free fatty acids, and heating or blowing air through it speeds its drying.","aka":["flaxseed oil","flax oil","boiled linseed oil"],"inputs":["flax"],"uses":["stained-glass"],"grounds":["flax"],"upstreamSlugs":["flax"],"downstreamSlugs":["stained-glass"],"steps":[{"name":"Clean the dried seed","process":"separate","text":"Dried, ripened flaxseed is cleaned at the mill. Varieties grown for seed yield more of it than those grown for linen fiber, and flax needs less pretreatment than oilseeds that must be cracked or flaked.","inputs":["flax"]},{"name":"Cook the seed","process":"cook","text":"Stacked cooking and drying vessels heat the seed until its cell walls rupture, which lets the oil escape more easily. High heat harms the flavor, so food-grade lines skip this.","inputs":[]},{"name":"Squeeze in an expeller","process":"press","text":"A screw press crushes the seed. Without cooking the press works harder, and processors often press twice. Friction alone can warm cold-pressed oil to 104 degrees Fahrenheit.","inputs":[]},{"name":"Dissolve out the rest","process":"separate","text":"Industrial oil comes from heat-treated, pre-pressed seed soaked in hexane. Further processing drives the solvent out of both the oil and the meal. High-protein meal gets heated and pressed into cakes for livestock.","inputs":[]},{"name":"Refine the raw oil","process":"wash","text":"Refining removes free fatty acids, gums and other stray material, and alkali treatment gives one common grade. Other lots are left in the sun to bleach or thicken for painters.","inputs":[]},{"name":"Heat or blow it","process":"cook","text":"Heat sets off polymerization, thickening the oil and cutting its drying time. Boiled oil, despite the name, usually means raw oil and stand oil blended with metallic or petroleum-based drying agents.","inputs":[]},{"name":"Ship by grade","process":"package","text":"Oil leaves as raw, refined, boiled or blown. Raw dries slowest, and boiled and blown form the hardest films, which suits paints and printing inks.","inputs":[]}],"facts":["The 1991 fire that badly damaged One Meridian Plaza in Philadelphia, killing three firefighters, was thought to be caused by rags soaked in linseed oil.","Linoleum, invented in 1860, binds wood dust and cork particles together with linseed oil.","Artists' oil paint is made by grinding raw pigment into linseed oil."],"where":[],"whereNote":null,"sources":[{"title":"Optimizing flaxseed oil production, Anderson International","url":"https://www.andersonintl.com/optimizing-flaxseed-oil-production"},{"title":"Linseed oil, Britannica","url":"https://www.britannica.com/science/linseed-oil"},{"title":"Linseed oil","url":"https://en.wikipedia.org/wiki/Linseed_oil"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lipstick","name":"Lipstick","kind":"product","category":"body-health","title":"How lipstick is made","url":"https://assemblyline.org/make/lipstick","stations":7,"upstream":35,"downstream":0,"depth":7,"dek":"Red lipstick was once colored with carmine, a dye crushed from cactus-feeding insects.","answer":"Lipstick is a blend of waxes, oils and pigment. Pigments are ground into oil until smooth, then mixed with melted waxes. The hot liquid is poured into a metal mold, chilled until it sets, popped out as a stick and flamed lightly on the surface for shine before it is placed in its case.","aka":["lip color","lip stick"],"inputs":["castor-beans","titanium-dioxide","iron-ore","pigment","honeycomb","paraffin-wax","aluminum","abs-plastic"],"uses":[],"grounds":["castor-beans","iron-ore","honeycomb","titanium-ore","sulfur","crude-oil","coal","air","rock-salt","water","natural-gas","bauxite","limestone"],"upstreamSlugs":["castor-beans","titanium-dioxide","iron-ore","pigment","honeycomb","paraffin-wax","aluminum","abs-plastic","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","carbon-black","sulfur","crude-oil","hydrogen","coal","petroleum-coke","alumina","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","rock-salt","water","natural-gas","bauxite","caustic-soda","lime","toluene","limestone"],"downstreamSlugs":[],"steps":[{"name":"Grind pigment into oil","process":"grind","text":"Pigments and mineral powders are rolled with castor oil or similar oil through steel rollers until no gritty specks remain. A smooth paste means an even color on the lips.","inputs":["castor-beans","titanium-dioxide","iron-ore","pigment"]},{"name":"Melt the waxes","process":"melt","text":"Beeswax, other waxes and lanolin are heated together in a kettle. They give the stick its firmness and set how it glides.","inputs":["honeycomb","paraffin-wax"]},{"name":"Blend the batch","process":"mix","text":"Pigment paste is stirred into the hot wax, along with flavor and a small amount of fragrance. Operators hold the mixture liquid and check it against a color standard.","inputs":[]},{"name":"Pour into molds","process":"cast","text":"Hot liquid goes into a metal mold with many stick-shaped cavities.","inputs":[]},{"name":"Chill until firm","process":"chill","text":"Loaded molds go into a cooler until the lipstick hardens enough to come out whole. Cold also gives the wax a fine grain.","inputs":[]},{"name":"Flame the surface","process":"coat","text":"Each stick is released from the mold and passed briefly through a flame. A light melt glazes the surface to a glossy finish and hides small marks.","inputs":[]},{"name":"Seat it in the case","process":"assemble","text":"Sticks are pushed into twist-up metal or plastic cases, capped, inspected and labeled.","inputs":["aluminum","abs-plastic"]}],"facts":["The first commercial lipstick appeared in Paris in 1884, wrapped in silk paper and made from deer tallow, castor oil and beeswax.","Carminic acid makes up 17% to 24% of the weight of the dried cochineal insects that supplied the red dye."],"where":[],"whereNote":null,"sources":[{"title":"Lipstick","url":"https://en.wikipedia.org/wiki/Lipstick"},{"title":"Mascara","url":"https://en.wikipedia.org/wiki/Mascara"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lng","name":"Liquefied natural gas","kind":"product","category":"chemicals","title":"How natural gas is liquefied","url":"https://assemblyline.org/make/lng","stations":5,"upstream":1,"downstream":0,"depth":1,"dek":"Chilling natural gas to -162 °C shrinks it to one six-hundredth of its volume so ships can carry it.","answer":"Liquefied natural gas is natural gas cooled until it condenses into a liquid at about -162 °C, taking up roughly one six-hundredth of the gas volume. Plants first strip out dust, carbon dioxide, water and heavy hydrocarbons, then run it through successive refrigeration stages. Insulated tanks and ships hold the liquid at that temperature.","aka":["liquid natural gas","LNG","cryogenic natural gas"],"inputs":["natural-gas"],"uses":[],"grounds":["natural-gas"],"upstreamSlugs":["natural-gas"],"downstreamSlugs":[],"steps":[{"name":"Clean the gas","process":"wash","text":"Dust, carbon dioxide, helium, water and heavy hydrocarbons are removed first. Left in, they would freeze and cause upsets in the cold equipment.","inputs":["natural-gas"]},{"name":"Pre-cool with propane","process":"chill","text":"In the cascade process, three refrigeration cycles are chained, each sealed off from the gas. Propane circulating in its own loop does the first stage of cooling.","inputs":[]},{"name":"Cool further with ethylene","process":"chill","text":"Ethylene or ethane, also in a closed loop, takes the gas to a lower temperature in the intermediate stage.","inputs":[]},{"name":"Condense with methane","process":"chill","text":"A methane cycle brings the gas down to a liquid. Liquefaction is an energy-intensive process.","inputs":[],"spec":"-162 °C"},{"name":"Store in insulated tanks","process":"fill","text":"The liquid is kept in tanks with a cold inner shell inside an insulated outer one. Specialized tankers carry it to import terminals, where it is turned back into gas.","inputs":[]}],"facts":["Its energy per liter is about 2.4 times that of compressed natural gas, and 60 percent that of diesel.","The first commercial LNG plant opened in Cleveland, Ohio, in 1940, and a tank failure there in 1944 killed well over a hundred people."],"where":[],"whereNote":null,"sources":[{"title":"Liquefied natural gas","url":"https://en.wikipedia.org/wiki/Liquefied_natural_gas"},{"title":"Natural-gas processing","url":"https://en.wikipedia.org/wiki/Natural-gas_processing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lithium-brine","name":"Lithium brine","kind":"raw","category":"ground","title":"How lithium brine is pumped","url":"https://assemblyline.org/make/lithium-brine","stations":3,"upstream":0,"downstream":13,"depth":0,"dek":"Some lithium comes out of a desert salt flat where the sun does the work of a refinery.","answer":"Lithium brine is salty groundwater under dry salt flats, such as the Salar de Atacama in Chile. Wells pump it to the surface, where it is spread in large shallow ponds. Sun and wind evaporate the water for months, concentrating the lithium, which is then converted at a plant into lithium carbonate.","aka":["salar brine","lithium salt flat"],"inputs":[],"uses":["lithium-carbonate"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["lithium-carbonate","lithium-ion-cell","ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","electric-car"],"steps":[{"name":"Pump the brine up","process":"drill","text":"Wells sunk into the salt flat bring up lithium-rich brine from beneath the crust. In the Salar de Atacama the brine carries about 2,700 parts per million of lithium.","inputs":[],"spec":"about 2,700 ppm lithium"},{"name":"Let the sun concentrate it","process":"dry","text":"Brine is fed into a chain of shallow ponds. The Atacama gets under 30 millimeters of rain a year but loses 3,500 millimeters to evaporation, so the water leaves and salts and lithium stay behind.","inputs":[]},{"name":"Collect the strong solution","process":"separate","text":"As the brine moves from pond to pond, other salts crystallize out first. The lithium solution that remains is pumped to a plant and converted to lithium carbonate.","inputs":[]}],"facts":["The Salar de Atacama supplied about 36% of the world's lithium carbonate in 2017, followed by China with 23%.","Anaconda Company found the lithium in the brines in 1962 while searching for fresh water for its copper mining.","Chile, Bolivia and Argentina form the Lithium Triangle, known for its salt flats."],"where":[{"place":"Chile","share":"about 36% of world lithium carbonate, from the Salar de Atacama alone"},{"place":"China","share":"23% of world lithium carbonate"}],"whereNote":"Share of the world's lithium carbonate supply in 2017.","sources":[{"title":"Salar de Atacama","url":"https://en.wikipedia.org/wiki/Salar_de_Atacama"},{"title":"Lithium","url":"https://en.wikipedia.org/wiki/Lithium"},{"title":"Salt evaporation pond","url":"https://en.wikipedia.org/wiki/Salt_evaporation_pond"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lithium-carbonate","name":"Lithium carbonate","kind":"material","category":"electronics","title":"How lithium carbonate is made","url":"https://assemblyline.org/make/lithium-carbonate","stations":8,"upstream":19,"downstream":12,"depth":5,"dek":"Brine can sit in open ponds for months or years until the sun has taken most of its water.","answer":"Lithium carbonate comes from two places. Salar brine is pumped into sun-baked ponds for months or years, cleaned of contaminants and dosed with sodium carbonate. Spodumene rock is mined, crushed, roasted until reactive and treated with sulfuric acid, giving a lithium sulfate solution that meets the same sodium carbonate. Either way, the solid product is filtered, washed and dried.","aka":["Li2CO3","battery-grade lithium"],"inputs":["lithium-brine","spodumene","sulfuric-acid","soda-ash","water"],"uses":["lithium-ion-cell"],"grounds":["lithium-brine","spodumene","water","sulfur","air","rock-salt","limestone","trona","natural-gas","corn","sugarcane","sugar-beet"],"upstreamSlugs":["lithium-brine","spodumene","sulfuric-acid","soda-ash","water","sulfur","air","rock-salt","ammonia","limestone","carbon-dioxide","lime","trona","natural-gas","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["lithium-ion-cell","ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","electric-car"],"steps":[{"name":"Pump up salar brine","process":"drill","text":"Salty groundwater enriched with dissolved lithium sits under high-altitude salt flats in places such as Chile and Argentina. It is pumped to the surface and spread across evaporation ponds.","inputs":["lithium-brine"]},{"name":"Evaporate through the ponds","process":"dry","text":"The sun takes most of the water over months or years. Each move to a new pond leaves a stronger solution, and potassium may be pulled from the younger ponds while the lithium builds.","inputs":[]},{"name":"Clean the concentrate","process":"separate","text":"At the recovery plant, filters or ion exchange remove unwanted material. Reagents then drop other salts out of solution, and a second filtering takes those solids away. The details vary with each brine field.","inputs":[]},{"name":"Mine and crush the ore","process":"crush","text":"On the hard-rock route, crews blast and dig spodumene from granitic pegmatites. It is graded and crushed so the plant gets a steady feed, and concentrates for this use hold 75 to 87% spodumene.","inputs":["spodumene"]},{"name":"Roast the concentrate","process":"bake","text":"Spodumene in its natural alpha form barely reacts. Strong heat converts it to the more open beta form, which can trade its lithium for hydrogen in the next step.","inputs":[],"spec":"about 1,070 °C"},{"name":"React with sulfuric acid","process":"react","text":"Cooled and mixed with concentrated acid, the roasted mineral gives up its lithium as lithium sulfate. Calcium hydroxide neutralizes the mix, and the waste solids are dewatered and washed. Further neutralizing steps take out iron, aluminum and magnesium.","inputs":["sulfuric-acid"]},{"name":"Precipitate with soda ash","process":"react","text":"Sodium carbonate goes into the purified solution from either route. The product dissolves poorly compared with other lithium salts, so it falls out as a solid. One outline of the spodumene route puts the conversion at 98%.","inputs":["soda-ash"]},{"name":"Wash and dry the powder","process":"wash","text":"A rotary vacuum filter washes the crystals, and the solids are dried for sale. Some is later slurried with calcium hydroxide to make lithium hydroxide for battery makers.","inputs":["water"]}],"facts":["Seawater contains an estimated 230 billion tonnes of lithium, yet only 0.14 to 0.25 parts in every million of it are lithium.","Lithium carbonate colors fireworks red.","A mild carbon dioxide pressure makes it appear ten times more soluble in water."],"where":[],"whereNote":null,"sources":[{"title":"Lithium carbonate","url":"https://en.wikipedia.org/wiki/Lithium_carbonate"},{"title":"Lithium","url":"https://en.wikipedia.org/wiki/Lithium"},{"title":"Lithium Deposits Australia, Earth Science Australia","url":"https://earthsci.org/mineral/mindep/lithium/lithium.html"},{"title":"Global demand for green minerals is rising, Mining Technology","url":"https://www.mining-technology.com/sponsored/global-demand-for-green-minerals-is-rising/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lithium-ion-cell","name":"Lithium-ion cell","kind":"product","category":"electronics","title":"How lithium-ion cells are made","url":"https://assemblyline.org/make/lithium-ion-cell","stations":10,"upstream":54,"downstream":11,"depth":6,"dek":"Lithium ions shuttle between a graphite sheet on copper foil and a metal oxide on aluminum foil.","answer":"Cell plants mix cathode and anode slurries, coat them onto aluminum and copper foil, dry the sheets and roll them to a set thickness. Electrodes slit to width are wound or stacked with a separator, welded to terminals and enclosed. A partial vacuum then draws in electrolyte, and the first slow charge builds a protective film inside.","aka":["Li-ion cell","lithium-ion battery cell","18650 cell","lithium polymer cell"],"inputs":["lithium-carbonate","cobalt","nickel","manganese","synthetic-graphite","aluminum","copper","polyethylene","steel"],"uses":["ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush"],"grounds":["lithium-brine","spodumene","water","cobalt-ore","nickel-ore","manganese-ore","iron-ore","natural-gas","crude-oil","coal","copper-ore","air","sulfur","rock-salt","limestone","trona","bauxite","dolomite","corn","quartz","timber","sugarcane","sugar-beet"],"upstreamSlugs":["lithium-carbonate","cobalt","nickel","manganese","synthetic-graphite","aluminum","copper","polyethylene","steel","lithium-brine","spodumene","sulfuric-acid","soda-ash","water","cobalt-ore","nickel-ore","manganese-ore","iron-ore","coke","natural-gas","crude-oil","petroleum-coke","coal","alumina","copper-ore","oxygen","air","ethylene","pig-iron","magnesium","steel-scrap","lime","argon","sulfur","rock-salt","ammonia","limestone","carbon-dioxide","trona","bauxite","caustic-soda","naphtha","dolomite","silicon","propane","corn","yeast","hydrogen","quartz","charcoal","timber","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","electric-car"],"steps":[{"name":"Mix the slurries","process":"mix","text":"Active powders are blended with binders and conductive additives into something like thick paint, with magnetic filters catching stray metal. Cathode and anode batches stay separate.","inputs":["lithium-carbonate","cobalt","nickel","manganese","synthetic-graphite"]},{"name":"Coat the foils","process":"coat","text":"A slot die lays slurry onto moving foil, metal oxide onto aluminum for the cathode and graphite onto copper for the anode. Width has to be right to within 0.1 mm, and the edges are the hard part.","inputs":["aluminum","copper"]},{"name":"Dry the coating","process":"dry","text":"Convective air dryers run right after coating, and the solvent is recovered. Anode lines add infrared as a booster.","inputs":[]},{"name":"Calender to thickness","process":"roll","text":"Rollers press the sheet to a controlled thickness and porosity, without letting it crack.","inputs":[]},{"name":"Slit and dry again","process":"cut","text":"Electrodes run up to 1.5 m wide until blades cut them to cell width. A burr here could pierce the separator later and cause a short. A second drying removes the last solvent and water.","inputs":[]},{"name":"Wind or stack","process":"assemble","text":"For a cylinder, anode, separator and cathode wind into a spiral. Pouch cells stack the layers one by one. Alignment matters, as does avoiding any puncture.","inputs":["polyethylene"]},{"name":"Weld the terminals","process":"weld","text":"Gathered foils are joined to their tabs by laser, spot or ultrasonic welding, with care that no spatter stays in the cell.","inputs":[]},{"name":"Close the can","process":"assemble","text":"The roll or stack goes into a can or heat-sealed pouch. A high-voltage test then checks for debris, folds and holes in the separator.","inputs":["steel"]},{"name":"Fill with electrolyte","process":"fill","text":"A partial vacuum pulls a set dose of electrolyte through every layer of the dry cell. Weighing the cell before and after confirms the fill.","inputs":[]},{"name":"Form and age","process":"inspect","text":"Each cell gets its first charge under tight control of current and temperature, which builds a microscopic protective layer on the anode. Cells rest for days or weeks while sensors watch for voltage drift, and every one is graded.","inputs":[]}],"facts":["In the three decades since Li-ion batteries were first sold in 1991, their volumetric energy density tripled and their cost dropped tenfold.","Cells come in three shapes: cylindrical cans, prismatic cases and soft pouches."],"where":[],"whereNote":null,"sources":[{"title":"Battery Design: Battery cell manufacturing process","url":"https://www.batterydesign.net/manufacture/cell-manufacturing/battery-cell-manufacturing-process/"},{"title":"MeraEV: How an EV battery is made","url":"https://www.meraev.com/blog/how-an-ev-battery-is-made-the-lithium-ion-manufacturing-process-from-powder-to-pack"},{"title":"Lithium-ion battery","url":"https://en.wikipedia.org/wiki/Lithium-ion_battery"},{"title":"Lithium carbonate","url":"https://en.wikipedia.org/wiki/Lithium_carbonate"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"locomotive","name":"Locomotive","kind":"product","category":"machines","title":"How locomotives are made","url":"https://assemblyline.org/make/locomotive","stations":8,"upstream":94,"downstream":0,"depth":10,"dek":"Most diesel locomotives do not drive the wheels with the engine. The diesel makes electricity, and motors turn the axles.","answer":"A diesel-electric locomotive is a steel frame carrying a big diesel engine, a generator or alternator and electric traction motors. The frame is welded, the wheelsets and bogies are built separately, and the engine and electrics are mounted and wired. The body is lowered on the bogies, painted, and tested on track.","aka":["engine","diesel-electric locomotive","train engine"],"inputs":["steel","steel-beam","ball-bearing","electric-motor","car-engine","copper-wire","printed-circuit-board","paint","diesel"],"uses":[],"grounds":["silica-sand","water","crude-oil","iron-ore","limestone","air","dolomite","manganese-ore","natural-gas","coal","copper-ore","titanium-ore","sulfur","quartz","timber","zinc-ore","rock-salt","bauxite","corn","sugarcane","trona","tin-ore","lead-ore","silver-ore","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["steel","steel-beam","ball-bearing","electric-motor","car-engine","copper-wire","printed-circuit-board","paint","diesel","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","steel-wire","sheet-steel","epoxy","aluminum","silica-sand","gasoline","copper","fiberglass","photoresist","solder","water","titanium-dioxide","pigment","acrylic","tin-can","crude-oil","hydrogen","biodiesel","iron-ore","coke","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","zinc","phenol","propylene","acetone","chlorine","caustic-soda","coal","petroleum-coke","alumina","naphtha","ethanol","copper-ore","soda-ash","phenolic-resin","tin","lead","silver","titanium-ore","carbon-black","sulfur","ammonia","methanol","tinplate","lacquer","ink","vegetable-oil","quartz","charcoal","timber","zinc-ore","benzene","rock-salt","bauxite","corn","sugarcane","yeast","ethylene","carbon-dioxide","trona","formaldehyde","tin-ore","lead-ore","silver-ore","soybeans","rapeseed","hexane","clay","toluene","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Weld the underframe","process":"weld","text":"Heavy steel plate and beams are welded into the underframe, the backbone that carries the engine and takes the pull of a train.","inputs":["steel","steel-beam"]},{"name":"Forge the wheels and axles","process":"forge","text":"Wheels and axles are forged and machined to shape, then pressed together as wheelsets. They have to cope with huge weights on small contact patches.","inputs":["steel"]},{"name":"Build the bogies","process":"assemble","text":"Wheelsets, bearings and springs are mounted in a steel truck, called a bogie. Each axle has a traction motor hung on it, with gears linking motor to axle.","inputs":["ball-bearing","electric-motor"]},{"name":"Assemble the diesel engine","process":"assemble","text":"The prime mover is a large diesel with many cylinders. It is built up from a cast block, crankshaft, pistons and heads in the same way as a car engine, only far bigger.","inputs":["car-engine"]},{"name":"Couple the generator","process":"assemble","text":"The engine drives a main generator, or on bigger units an alternator with rectifier, whose electricity is carried by thick cables to the traction motors.","inputs":["copper-wire"]},{"name":"Wire the control system","process":"assemble","text":"Governor and electronic controls manage engine speed and the electrical load. A single throttle lever coordinates engine and generator, a scheme worked out by Hermann Lemp.","inputs":["printed-circuit-board"]},{"name":"Lower the body on the bogies","process":"assemble","text":"A crane lifts the finished body and sets it down on its bogies. Brake lines and cabling are then connected.","inputs":[]},{"name":"Paint and test on track","process":"coat","text":"After painting, the locomotive is fueled and run on a test track, pulling load units to confirm power and braking.","inputs":["paint","diesel"]}],"facts":["Werner von Siemens showed an electric locomotive in Berlin in 1879. Its 2.2 kW motor pulled three cars at 13 km/h, and it carried 90,000 passengers in four months.","By 1925 a small number of diesel locomotives of 600 horsepower were in service in the United States."],"where":[],"whereNote":null,"sources":[{"title":"Locomotive","url":"https://en.wikipedia.org/wiki/Locomotive"},{"title":"Diesel locomotive","url":"https://en.wikipedia.org/wiki/Diesel_locomotive"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lollipop","name":"Lollipop","kind":"product","category":"food","title":"How lollipops are made","url":"https://assemblyline.org/make/lollipop","stations":6,"upstream":9,"downstream":0,"depth":3,"dek":"A lollipop is sugar glass, and it only stays clear because corn syrup keeps the sugar from crystallizing.","answer":"A lollipop is a stick of hard candy made by boiling sugar and corn syrup with water until almost all the moisture is gone. The syrup cools into a glassy solid instead of crystals, with less than 2 percent water left. Flavor and color go in near the end, and the candy is shaped around a stick.","aka":["sucker","lolly","hard candy on a stick"],"inputs":["sugar","corn-syrup","water"],"uses":[],"grounds":["water","sugarcane","sugar-beet","corn","limestone"],"upstreamSlugs":["sugar","corn-syrup","water","sugarcane","sugar-beet","lime","corn","corn-starch","limestone"],"downstreamSlugs":[],"steps":[{"name":"Dissolve the sugar","process":"mix","text":"Sugar and corn syrup are stirred into water. Water is needed only at the start. The corn syrup is the ingredient that blocks crystal growth later.","inputs":["sugar","corn-syrup","water"]},{"name":"Boil away the water","process":"cook","text":"The syrup is heated well past the boiling point of water so nearly all the moisture leaves. Many hard candies are cooked to around 154 degrees Celsius, though the exact figure depends on the batch.","inputs":[],"spec":"around 154 °C"},{"name":"Stir in flavor and color","process":"mix","text":"Flavoring and dye go into the hot syrup. Extras such as a bubble gum center can be added as well, though they are not part of the basic structure.","inputs":[]},{"name":"Shape it on the stick","process":"mold","text":"The thick hot syrup is formed into its shape while it still flows, with a stick set into it.","inputs":[]},{"name":"Cool into glass","process":"chill","text":"As the candy cools it passes through the glass transition and goes hard without crystallizing. The finished moisture is only 1 to 2 percent, compared with 8 to 12 percent in crystalline candies.","inputs":[],"spec":"1 to 2% water"},{"name":"Wrap each one","process":"package","text":"Each lollipop is wrapped to keep out humidity, because moisture from the air would make the glass sticky.","inputs":[]}],"facts":["One account says George Smith of New Haven started making hard candy on sticks in 1908 and named it after a racehorse called Lolly Pop.","Candy on sticks goes back to the Middle Ages, when nobles ate boiled sugar with the help of handles.","Some lollipops carry medicine, a way of giving children medicine without a fuss."],"where":[],"whereNote":null,"sources":[{"title":"Lollipop","url":"https://en.wikipedia.org/wiki/Lollipop"},{"title":"Hard candy","url":"https://en.wikipedia.org/wiki/Hard_candy"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"loudspeaker","name":"Loudspeaker","kind":"product","category":"electronics","title":"How loudspeakers are made","url":"https://assemblyline.org/make/loudspeaker","stations":10,"upstream":70,"downstream":0,"depth":9,"dek":"The magnet in a loudspeaker is not a magnet at all until the assembly reaches the end of the production line.","answer":"A speaker driver pairs a voice coil with a permanent magnet. The coil is wound on a steel mandrel and baked, metal plates are stamped and coated, and a magnet is sandwiched between them. The cone, spider and surround are glued in, the magnet is charged at the end of the line, and the driver is bolted into a cabinet.","aka":["speaker","speaker driver","woofer"],"inputs":["copper-wire","adhesive","steel","epoxy","paper","polypropylene","neodymium-magnet","ferrite","rubber","mdf","plywood","screw"],"uses":[],"grounds":["water","kaolin","limestone","rare-earth-ore","iron-ore","manganese-ore","natural-latex","sulfur","timber","copper-ore","air","crude-oil","dolomite","natural-gas","rock-salt","nickel-ore","zinc-ore","coal","quartz"],"upstreamSlugs":["copper-wire","adhesive","steel","epoxy","paper","polypropylene","neodymium-magnet","ferrite","rubber","mdf","plywood","screw","copper","polyethylene","acrylic","polyurethane","paraffin-wax","water","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","phenol","propylene","acetone","chlorine","caustic-soda","wood-pulp","kaolin","limestone","rare-earth-ore","nickel","zinc","iron-ore","zinc-oxide","manganese-ore","natural-latex","synthetic-rubber","carbon-black","sulfur","timber","steel-wire","copper-ore","air","sulfuric-acid","ethylene","ammonia","methanol","nitric-acid","crude-oil","hydrogen","coke","dolomite","silicon","propane","natural-gas","benzene","naphtha","rock-salt","hydrogen-peroxide","nickel-ore","zinc-ore","styrene","coal","quartz","charcoal","toluene"],"downstreamSlugs":[],"steps":[{"name":"Wind the voice coil","process":"assemble","text":"A former of paper, Kapton or fiberglass is wrapped around a steel mandrel that keeps it round. Copper wire is wound on, and the coil is baked to cure the adhesive coating the wire.","inputs":["copper-wire","adhesive"]},{"name":"Stamp the metal parts","process":"stamp","text":"Top and back plates are stamped from rolls of steel, and baskets are stamped from steel or cast in aluminum. The plates are welded or staked to the basket and the core.","inputs":["steel"]},{"name":"E-coat the metal","process":"coat","text":"The assembled metal parts go through an electro-coat paint line, which puts an even layer of cationic epoxy over the whole surface to stop corrosion.","inputs":["epoxy"]},{"name":"Form the cone","process":"mold","text":"Paper pulp, polypropylene or another light material is pressed into a shallow cone. It has to be stiff enough not to flex and light enough to start and stop quickly.","inputs":["paper","polypropylene"]},{"name":"Assemble the motor","process":"assemble","text":"A ferrite or neodymium magnet, not yet magnetized, is sandwiched between the plates, which focus its field into a narrow gap around the core.","inputs":["neodymium-magnet","ferrite"]},{"name":"Join cone and suspension","process":"assemble","text":"The voice coil goes into the gap without touching the sides, and the cone is glued to it. A flexible surround at the outer edge and a corrugated spider hold the coil centered.","inputs":["rubber","adhesive"]},{"name":"Charge the magnet","process":"assemble","text":"At the end of the line the finished assembly passes through a magnetizer, and the magnet takes on its permanent field.","inputs":[]},{"name":"Build the cabinet","process":"machine","text":"Fiberboard or plywood panels are cut, glued and sealed into a box. The cabinet is needed so that sound from the back of the driver does not cancel the sound from the front.","inputs":["mdf","plywood","adhesive"]},{"name":"Wire the crossover","process":"assemble","text":"In multi-driver speakers, a small circuit of coils and capacitors splits the signal into frequency ranges for each driver. The drivers and crossover are screwed in and wired.","inputs":["copper-wire","screw"]},{"name":"Test the response","process":"inspect","text":"Each speaker plays test tones in a measuring chamber, and the response is compared with a reference curve before it is packed.","inputs":[]}],"facts":["Eminence, a Kentucky speaker maker, uses over 360,000 magnets each year.","In a powered speaker, the amplifier is built into the cabinet, which is common in computer and Bluetooth speakers."],"where":[],"whereNote":null,"sources":[{"title":"Loudspeaker","url":"https://en.wikipedia.org/wiki/Loudspeaker"},{"title":"Voice coil","url":"https://en.wikipedia.org/wiki/Voice_coil"},{"title":"How speakers are built (Eminence)","url":"https://www.eminence.com/how-speakers-are-built/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lumber","name":"Lumber","kind":"material","category":"wood-paper","title":"How lumber is made","url":"https://assemblyline.org/make/lumber","stations":6,"upstream":1,"downstream":23,"depth":1,"dek":"A two-by-four is neither two inches nor four inches. It shrank on the way from the log to the store.","answer":"Lumber is a log sawn into boards and beams. A sawmill strips the bark, runs the log through saws that turn it into rough boards, then dries them in a kiln or in open air so they stop warping. Planers smooth the faces to standard sizes, and graders sort every board by strength and defects.","aka":["timber boards","sawn wood","dimensional lumber","planks"],"inputs":["timber"],"uses":["pencil","kitchen-knife","whiskey","rum","tequila","electric-guitar","piano","clothespin","laminate-floor","wooden-chair","door","sofa","ski","snowboard","chess-set","harmonica","ukulele","cello","drumstick","hammer","shovel","canoe","match"],"grounds":["timber"],"upstreamSlugs":["timber"],"downstreamSlugs":["pencil","kitchen-knife","whiskey","rum","tequila","electric-guitar","piano","clothespin","laminate-floor","wooden-chair","door","sofa","ski","snowboard","chess-set","harmonica","ukulele","cello","drumstick","hammer","shovel","canoe","match"],"steps":[{"name":"Strip the bark","process":"machine","text":"Logs arrive at the mill and go through a debarker that scrubs the bark off. The bark is not wasted. Mills burn it for heat or sell it as landscaping mulch.","inputs":["timber"]},{"name":"Saw the log into boards","process":"cut","text":"A big saw works its way through the log. Cutting straight through gives plain-sawn boards with the grain running across the width, while turning the log between cuts gives boards whose growth rings stand more upright. Sawing is far quicker than hewing or splitting a log by hand.","inputs":[]},{"name":"Trim and split to width","process":"cut","text":"Edgers square off the wavy sides of each board, and resaws split thick pieces into thinner ones of the same length.","inputs":[]},{"name":"Dry out the boards","process":"dry","text":"Fresh wood is full of water that sits inside its cell walls. Boards are stacked and dried in a heated kiln or left to air-dry, because wood that dries unevenly splits, bows and develops hidden cracks. Dry wood below about 25 percent moisture can stay free of decay for centuries.","inputs":[],"spec":"below 25% moisture"},{"name":"Plane to standard size","process":"machine","text":"Rotating knives shave the faces and edges smooth. This is where a 2x4 shrinks. Modern standards describe the finished size, and a 2x4 ends up 38 by 89 mm.","inputs":[],"spec":"38 by 89 mm"},{"name":"Grade every board","process":"inspect","text":"Inspectors, or machines that measure stiffness or density, sort the boards by knots, splits and strength. The grade stamp tells a builder how much load a board can be trusted to carry.","inputs":[]}],"facts":["About 80 percent of lumber comes from softwood trees such as pine, fir and spruce.","A Dutch windmill owner built the first wind-powered sawmill in 1593, and it cut logs into planks thirty times faster than hand sawing.","Historically, a board's nominal size, such as 2x4, was the size of the green, rough-sawn board, and finished lumber is smaller than its nominal dimensions after drying and planing."],"where":[],"whereNote":null,"sources":[{"title":"Lumber","url":"https://en.wikipedia.org/wiki/Lumber"},{"title":"Sawmill","url":"https://en.wikipedia.org/wiki/Sawmill"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"magnesium","name":"Magnesium","kind":"material","category":"metals","title":"How magnesium metal is made","url":"https://assemblyline.org/make/magnesium","stations":5,"upstream":7,"downstream":162,"depth":3,"dek":"Most magnesium metal is baked out of dolomite rock in vacuum-sealed steel tubes.","answer":"Magnesium rarely occurs as a metal, so it is smelted from rock. In the Pidgeon process, dolomite is fired into magnesium oxide, mixed with ferrosilicon and heated in a vacuum until magnesium vapor condenses as crystals. Electrolysis of magnesium chloride, often from brine or seawater, is the other main route.","aka":["magnesium metal","Mg"],"inputs":["dolomite","silicon"],"uses":["steel","titanium","water-heater","toy-car","digital-camera"],"grounds":["dolomite","quartz","coal","timber"],"upstreamSlugs":["dolomite","silicon","quartz","coke","coal","charcoal","timber"],"downstreamSlugs":["steel","titanium","water-heater","toy-car","digital-camera","toothbrush","lithium-ion-cell","ev-battery","aa-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","inkjet-printer","electric-toothbrush","pacemaker","hip-implant","jet-engine","prosthetic-leg","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","e-reader","electric-car","refrigerator","microwave-oven","washing-machine","blender","air-conditioner","treadmill","game-console","graphics-card","phone-charger","safety-pin","car","airbag","ceiling-fan","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","concrete","skyscraper","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sailboat","action-figure","power-outlet","champagne","electric-kettle","pencil","mirror","golf-ball","wallpaper","wooden-chair","water-bottle","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","snow-globe","neon-sign","aluminum-window-frame","toffee"],"steps":[{"name":"Fire the dolomite","process":"fire","text":"Dolomite is calcined to drive off carbon dioxide. What remains is a mixed oxide of magnesium and calcium.","inputs":["dolomite"]},{"name":"Blend in the reducing agent","process":"mix","text":"The calcined rock is mixed with ferrosilicon, which strips the oxygen from the magnesium. Ferrosilicon is used in place of pure silicon because it is cheaper.","inputs":["silicon"],"spec":"75% ferrosilicon"},{"name":"Heat it in a vacuum tank","process":"melt","text":"The mixture is heated from outside in a sealed reduction tank under vacuum. Magnesium comes off as a vapor, while the calcium ends up as calcium silicate.","inputs":[]},{"name":"Collect the crystals","process":"separate","text":"The vapor condenses on a cooler part of the tank as crystals, which crews pull out once the tank is opened.","inputs":[]},{"name":"Remelt into ingots","process":"cast","inputs":[],"text":"The crystals are remelted and cast into ingots, which go to alloy makers and die casters."}],"facts":["Magnesium is the second-most-abundant cation in seawater, so the ocean is a workable ore for plants that use electrolysis.","The United States supplied 45 percent of world magnesium as recently as 1995, and only 7 percent by 2013 as China took over.","Magnesium ranks eighth in abundance among elements in Earth's crust."],"where":[{"place":"China","share":"930 kt of about 1,100 kt"},{"place":"Russia","share":"60 kt"}],"whereNote":"World production in 2017, per Wikipedia.","sources":[{"title":"Magnesium","url":"https://en.wikipedia.org/wiki/Magnesium"},{"title":"Pidgeon process","url":"https://en.wikipedia.org/wiki/Pidgeon_process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"malted-barley","name":"Malted barley","kind":"material","category":"food","title":"How malted barley is made","url":"https://assemblyline.org/make/malted-barley","stations":5,"upstream":2,"downstream":18,"depth":1,"dek":"Maltsters trick barley into thinking it is spring, then roast it just as its enzymes peak.","answer":"Grain gets soaked until it starts to sprout, because a sprouting seed makes the enzymes that turn starch into sugar. The maltster lets that run for several days, then stops it with hot air before the young plant uses up the starch. Brewers and distillers buy the result, with its enzymes still alive.","aka":["malt","barley malt","pale malt","base malt"],"inputs":["barley","water"],"uses":["vinegar","corn-flakes","beer","whiskey","bagel","caramel-color","scotch","light-beer","non-alcoholic-beer"],"grounds":["barley","water"],"upstreamSlugs":["barley","water"],"downstreamSlugs":["vinegar","corn-flakes","beer","whiskey","bagel","caramel-color","scotch","light-beer","non-alcoholic-beer","mayonnaise","ketchup","mustard","hot-sauce","salsa","pickles","cola","rum","soda"],"steps":[{"name":"Dry and rest the grain","process":"dry","text":"Barley arriving with more than 13% moisture is dried with air up to 50 °C, gently enough to keep the embryo alive. It then sits in silos for around six weeks to get past seed dormancy, with temperature watched for signs of insects.","inputs":["barley"]},{"name":"Steep in water","process":"wash","text":"Water covers the grain and moisture climbs from around 12% to as much as 46%. Modern plants alternate wet stands with air rests for two or three cycles. Tiny white rootlets called chit show that the seeds have woken up.","inputs":["water"]},{"name":"Germinate on a slotted floor","process":"grow","text":"For about four to six days the grain grows while fans blow air up through the bed and big mechanical turners keep it loose. Enzymes build up inside each kernel. Barley's husk stays on and protects the growing shoot from damage.","inputs":[]},{"name":"Kiln the green grain","process":"dry","text":"The sprouted grain, called green malt, goes into a kiln where hot air stops the growth. Temperature sets the type. Keeping to 55 °C leaves the enzymes working, and hotter kilning gives darker colors.","inputs":[]},{"name":"Knock off the rootlets","process":"separate","text":"Soon after leaving the kiln, the dried rootlets, called culms, are removed and sold as animal feed. The clean malt goes to brewers and distillers, who later crack it and warm it in water to set the enzymes loose on the remaining starch.","inputs":[]}],"facts":["Malting barley takes about 7% of its extractable starch and turns it into other carbohydrates before the brewer ever sees it.","Floor maltings, where workers raked the grain by hand, began to be phased out in the 1940s.","Barley is the favorite grain for malting partly because its husk survives threshing and later forms a filter bed in the brewery."],"where":[],"whereNote":null,"sources":[{"title":"Malt","url":"https://en.wikipedia.org/wiki/Malt"},{"title":"Malting","url":"https://en.wikipedia.org/wiki/Malting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"manganese","name":"Manganese","kind":"material","category":"metals","title":"How manganese is made","url":"https://assemblyline.org/make/manganese","stations":6,"upstream":9,"downstream":158,"depth":2,"dek":"Nearly all manganese goes into steel, where it grabs sulfur and oxygen that would otherwise make the steel brittle.","answer":"Manganese is mined as pyrolusite and other ores, crushed, and most of it is smelted with iron ore and carbon into ferromanganese, 30 to 80 percent manganese, for steelmaking. Pure manganese for iron-free alloys is made by leaching ore with sulfuric acid and plating the metal out by electrowinning.","aka":["ferromanganese","manganese metal"],"inputs":["manganese-ore","iron-ore","coke","sulfuric-acid","natural-gas"],"uses":["thermometer","lithium-ion-cell","aa-battery","steel"],"grounds":["manganese-ore","iron-ore","natural-gas","coal","sulfur","air","water"],"upstreamSlugs":["manganese-ore","iron-ore","coke","sulfuric-acid","natural-gas","coal","sulfur","air","water"],"downstreamSlugs":["thermometer","lithium-ion-cell","aa-battery","steel","ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","toothbrush","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","inkjet-printer","electric-car","refrigerator","microwave-oven","washing-machine","blender","air-conditioner","treadmill","game-console","graphics-card","phone-charger","safety-pin","car","airbag","ceiling-fan","water-heater","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","concrete","skyscraper","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sailboat","action-figure","power-outlet","champagne","electric-kettle","pencil","mirror","golf-ball","wallpaper","wooden-chair","water-bottle","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","snow-globe","neon-sign","aluminum-window-frame","toffee"],"steps":[{"name":"Dig the ore","process":"mine","text":"The main ore is pyrolusite, manganese dioxide, which is dark brown to black. About 80 percent of the known manganese resource lies in South Africa, mostly in the Kalahari field near Hotazel.","inputs":["manganese-ore"]},{"name":"Crush and grind","process":"crush","text":"Ore is crushed and ground so that smelting or acid can reach every grain. For heap-leach routes the ore is ground to between 150 and 250 micrometers.","inputs":[]},{"name":"Smelt with iron ore and carbon","process":"melt","text":"To make ferromanganese, the ore is mixed with iron ore and carbon and reduced in a blast furnace or an electric arc furnace. The product holds 30 to 80 percent manganese.","inputs":["iron-ore","coke"]},{"name":"Tap the alloy","process":"cast","text":"Molten ferromanganese is run off and cast, then broken up for steelmakers who add it to ladles to fix sulfur and remove oxygen.","inputs":[]},{"name":"Leach in sulfuric acid","process":"react","text":"For iron-free manganese, ore is leached with sulfuric acid so that the manganese goes into solution. A different route reduces low-grade ore with natural gas at at least 850 °C so that it can be leached.","inputs":["sulfuric-acid","natural-gas"]},{"name":"Plate it out","process":"electrolyze","text":"The solution goes to an electrowinning plant, where an electric current deposits pure manganese metal.","inputs":[]}],"facts":["Manganese in steel fixes sulfur, removes oxygen and adds strength, and steelmaking accounts for 85 to 90 percent of demand.","Beverage cans are usually made from aluminum alloys 3004 and 3104, which hold 0.8 to 1.5 percent manganese.","Cave paintings at Gargas, 30,000 to 24,000 years old, are made from manganese dioxide pigment."],"where":[{"place":"South Africa","share":"3.4 million tons, the largest producer"}],"whereNote":"2011, manganese ore produced.","sources":[{"title":"Manganese","url":"https://en.wikipedia.org/wiki/Manganese"},{"title":"Ferroalloy","url":"https://en.wikipedia.org/wiki/Ferroalloy"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"manganese-ore","name":"Manganese ore","kind":"raw","category":"ground","title":"How manganese ore is mined","url":"https://assemblyline.org/make/manganese-ore","stations":5,"upstream":0,"downstream":161,"depth":0,"dek":"Manganese is why steel does not crack: it soaks up sulfur and oxygen before they can do harm.","answer":"Manganese ore is usually dug from open pits, and it only counts as commercial above about 35% manganese. Crews drill, blast, load and haul the rock to a plant that crushes and screens it, and some of it ships straight from there. Other ore is washed or run through gravity separation to raise its grade, while undersized pieces can be sintered into lumps.","aka":["pyrolusite"],"inputs":[],"uses":["manganese","ferrite"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["manganese","ferrite","thermometer","lithium-ion-cell","aa-battery","steel","headphones","phone-charger","loudspeaker","ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","toothbrush","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","inkjet-printer","electric-car","refrigerator","microwave-oven","washing-machine","blender","air-conditioner","treadmill","game-console","graphics-card","safety-pin","car","airbag","ceiling-fan","water-heater","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","concrete","skyscraper","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sailboat","action-figure","power-outlet","champagne","electric-kettle","pencil","mirror","golf-ball","wallpaper","wooden-chair","water-bottle","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","snow-globe","neon-sign","aluminum-window-frame","toffee"],"steps":[{"name":"Drill and blast the beds","process":"mine","text":"Conventional open-pit work breaks the ore with drilling and blasting, then loads and hauls it. South Africa's Kalahari field holds beds of pyrolusite and other oxides, and Tshipi Borwa near Hotazel is one of its big pits.","inputs":[]},{"name":"Crush and screen","process":"crush","text":"A plant crushes the rock, screens it and stockpiles it. Some of the output is ready to transport at this point, with no further treatment.","inputs":[]},{"name":"Wash off the waste","process":"wash","text":"Some ores are upgraded simply by washing, which raises the share of manganese before shipment.","inputs":[]},{"name":"Split by density","process":"separate","text":"At Tshipi, banded iron contaminants are broken down small and a gravity separation system turns out high-grade concentrate suited to steelmaking.","inputs":[]},{"name":"Sinter the undersize","process":"fire","text":"Pieces too small to use directly can be agglomerated by sintering, which binds them into larger lumps.","inputs":[]}],"facts":["South Africa holds about 80% of the manganese resources known worldwide.","South Africa's Kalahari manganese fields near Hotazel hold a 2011 estimate of 15 billion tons.","Aluminum with roughly 1.5% manganese resists corrosion well enough to be used for most beverage cans."],"where":[{"place":"South Africa","share":"3.4 million tons, the most of any nation"}],"whereNote":"Manganese mined in 2011.","sources":[{"title":"Manganese processing","url":"https://www.britannica.com/technology/manganese-processing"},{"title":"Tshipi Borwa Open Pit Mine","url":"https://www.mining-technology.com/projects/tshipi-mine/"},{"title":"Manganese","url":"https://en.wikipedia.org/wiki/Manganese"},{"title":"Pyrolusite","url":"https://en.wikipedia.org/wiki/Pyrolusite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"maple-sap","name":"Maple sap","kind":"raw","category":"farm","title":"How maple sap is collected","url":"https://assemblyline.org/make/maple-sap","stations":3,"upstream":0,"downstream":1,"depth":0,"dek":"Maple sap only runs on days above freezing, and a tree gives up just seven percent of it each season.","answer":"Maple sap is gathered in late winter and spring from trees tapped in a stand called a sugarbush. Each tree is tapped by boring a hole and driving in a spout. Sap flows on days when the temperature rises above freezing, and the taps stay in place for the four to eight weeks of the season.","aka":["maple tapping","sugar maple sap","sugaring","sugarbush"],"inputs":[],"uses":["maple-syrup"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["maple-syrup"],"steps":[{"name":"Bore the tap hole","process":"harvest","text":"Maples are usually tapped from 30 to 40 years of age. A hole is bored into the trunk and a spile is driven into it. A tree supports between one and three taps, depending on the width of its trunk.","inputs":[]},{"name":"Wait for a thaw","process":"harvest","text":"Sucrose stored in the roots rises through the trunk as sugary sap. It flows during the day when the temperature is above freezing, and the tap season lasts roughly four to eight weeks in late winter and spring.","inputs":[]},{"name":"Collect into containers","process":"harvest","text":"Sap drains from the spile into buckets, bags or tubing that leads to a central tank. An average tree gives 35 to 50 litres a season, up to 12 litres in a day, which is about seven percent of its sap. A tree can be tapped until it is over 100 years old.","inputs":[]}],"facts":["Syrup makers boil between 20 and 50 volumes of sap to get one volume of syrup.","Increasing late-winter warmth shifts the sap season earlier in the year.","Buckets have been largely replaced by plastic bags and tubing systems that carry sap to a central container."],"where":[{"place":"Canada","share":"more than 75% of world output"},{"place":"United States","share":"around 25%"}],"whereNote":"2025, share of world maple syrup production. Quebec makes about 90% of Canada's syrup.","sources":[{"title":"Maple syrup","url":"https://en.wikipedia.org/wiki/Maple_syrup"},{"title":"Sugar maple","url":"https://en.wikipedia.org/wiki/Sugar_maple"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"maple-syrup","name":"Maple syrup","kind":"product","category":"food","title":"How maple syrup is made","url":"https://assemblyline.org/make/maple-syrup","stations":7,"upstream":1,"downstream":0,"depth":1,"dek":"It takes 20 to 50 buckets of maple sap to boil down to a single bucket of syrup.","answer":"In late winter, maple trees are tapped and the sap, only a few percent sugar, runs through tubing to a sugar shack. Evaporator pans boil 20 to 50 volumes of sap down to one of syrup, ending a few degrees above the boiling point of water. The syrup is filtered and packed hot.","aka":["pure maple syrup","maple sugar"],"inputs":["maple-sap"],"uses":[],"grounds":["maple-sap"],"upstreamSlugs":["maple-sap"],"downstreamSlugs":[],"steps":[{"name":"Drill the tap holes","process":"harvest","text":"In late winter, starch stored in the trunk turns to sugar and rises with the sap. Workers drill into trunks and set spouts. A tree is usually tapped beginning at 30 to 40 years of age, with one to three taps depending on trunk size.","inputs":["maple-sap"]},{"name":"Pipe the sap downhill","process":"harvest","text":"Plastic tubing runs the sap from tree to tree and on to a central tank, often helped by vacuum pumps. An average tree gives 35 to 50 litres over a whole season.","inputs":[]},{"name":"Preheat the sap","process":"cook","text":"The sap is warmed with hot vapor from the evaporator, which saves fuel. Sap at this stage is only two to five percent sugar.","inputs":[]},{"name":"Boil it down","process":"cook","text":"In a shallow evaporator pan, between 20 and 50 volumes of sap are boiled to get one volume of syrup. Sweeter sap needs less. Sap at 1.5% sugar takes 57 units to make 1, and sap at 3.5% takes 25.","inputs":[]},{"name":"Draw off at the right density","process":"inspect","text":"The syrup maker watches the boiling point. Syrup is done at about 4.1 °C above the boiling point of water, or 66 on the Brix scale. Boiled too long, it crystallizes. Under-boiled syrup is watery and spoils quickly.","inputs":[],"spec":"66 Brix"},{"name":"Filter out sugar sand","process":"separate","text":"Hot syrup passes through a filter press that catches sugar sand, tiny crystals of sugar and calcium malate, which would cloud the syrup.","inputs":[]},{"name":"Grade and pack hot","process":"fill","text":"Syrup is graded by color and taste and packed into containers at about 82 °C or hotter. The sealed containers are tipped over so the hot syrup sterilizes the cap.","inputs":[]}],"facts":["Quebec alone makes 72% of the world's maple syrup.","In Canada, maple syrup must be at least 66 percent sugar and made only from maple sap.","Maples can keep being tapped until they are over 100 years old."],"where":[{"place":"Quebec","share":"72% of global output"}],"whereNote":"Share of world maple syrup output as reported by Wikipedia; almost all of the rest comes from the United States and other parts of Canada.","sources":[{"title":"Maple syrup","url":"https://en.wikipedia.org/wiki/Maple_syrup"},{"title":"Sugar","url":"https://en.wikipedia.org/wiki/Sugar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"marble","name":"Marble","kind":"raw","category":"ground","title":"How marble is quarried","url":"https://assemblyline.org/make/marble","stations":3,"upstream":0,"downstream":0,"depth":0,"dek":"Marble is limestone that was cooked and squeezed underground until its grains locked into a crystal mosaic.","answer":"Marble is limestone or dolomite that has recrystallized under heat and pressure. It is quarried, mostly as large blocks, by drilling and blasting, water jets or wedges. The blocks are sawn into slabs for floors, counters and sculpture.","aka":["carrara marble","polished stone"],"inputs":[],"uses":[],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":[],"steps":[{"name":"Drill and wedge the face","process":"mine","text":"Quarries make blocks, not rubble. Crews use drilling and blasting, water jets or wedges to separate a block from the rock face without cracking it.","inputs":[]},{"name":"Saw the blocks","process":"cut","text":"Blocks are hauled to a mill and sliced into slabs, keeping the veins and swirls that come from clay, silt, sand and iron oxides in the original limestone.","inputs":[]},{"name":"Polish for the finish","process":"grind","text":"Slabs are ground and polished until the crystals reflect light. White marble was prized for sculpture partly because it is soft enough to carve easily.","inputs":[]}],"facts":["Pure white marble comes from very clean limestone or dolomite, and veins come from impurities in the original rock.","In stonemasonry, the word marble is used more broadly than in geology, and includes unmetamorphosed limestone.","In 2018 Turkey was the world leader in marble export, with a 42% share in global marble trade."],"where":[{"place":"China","share":"34% of world marble and decorative stone"},{"place":"Italy","share":"19%"}],"whereNote":"Shares of world production of marble and decorative stone, as reported in the Wikipedia marble article (no year given).","sources":[{"title":"Marble","url":"https://en.wikipedia.org/wiki/Marble"},{"title":"Dimension stone","url":"https://en.wikipedia.org/wiki/Dimension_stone"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"margarine","name":"Margarine","kind":"product","category":"food","title":"How margarine is made","url":"https://assemblyline.org/make/margarine","stations":7,"upstream":14,"downstream":0,"depth":4,"dek":"Margarine is a water-in-fat emulsion invented in 1869 as an answer to a challenge from Napoleon III.","answer":"A margarine plant blends refined vegetable oils, some of them hardened or reshuffled to be solid at room temperature, with a water or soured-milk phase. Emulsifiers hold the mix together. It is then chilled rapidly, worked until smooth, and packed. Hippolyte Mege-Mouries invented margarine in 1869.","aka":["oleomargarine","spread","oleo"],"inputs":["vegetable-oil","palm-oil","hydrogen","water","table-salt"],"uses":[],"grounds":["water","soybeans","rapeseed","clay","oil-palm-fruit","natural-gas","rock-salt","seawater","crude-oil"],"upstreamSlugs":["vegetable-oil","palm-oil","hydrogen","water","table-salt","soybeans","rapeseed","hexane","clay","oil-palm-fruit","natural-gas","rock-salt","seawater","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Refine the oils","process":"refine","text":"Seed oils and palm oil are pressed or extracted, then refined to remove gums, color and flavor. The fat blend sets how hard the spread is.","inputs":["vegetable-oil","palm-oil"]},{"name":"Harden some of the oil","process":"react","text":"Part of the oil may be hardened by passing hydrogen through it over a nickel catalyst. This turns carbon double bonds into single ones and raises the melting point. Many brands now rely on fractionation and interesterification to avoid hydrogenation.","inputs":["hydrogen"]},{"name":"Make the water phase","process":"mix","text":"Water or skimmed milk, which may be soured, is mixed with salt, citric or lactic acid, a preservative and sometimes powdered skim milk.","inputs":["water","table-salt"]},{"name":"Dose the fat-soluble extras","process":"mix","text":"The fats are warmed until liquid. Emulsifiers such as lecithin, carotenoids for yellow color and antioxidants are stirred into the oil.","inputs":[]},{"name":"Emulsify the two phases","process":"mix","text":"Oil is run slowly into the water phase under constant stirring. The result is a smooth emulsion of tiny water droplets scattered through the fat.","inputs":[]},{"name":"Chill and work it","process":"chill","text":"The emulsion is chilled rapidly inside scraped-surface tubes, which prevents large fat crystals and gives a smooth texture. It is then rolled or kneaded.","inputs":[]},{"name":"Aerate and pack","process":"package","text":"Soft tub margarine may be whipped with nitrogen so it spreads more easily. It is packed into tubs or wrapped in paper blocks.","inputs":[]}],"facts":["The spread was first named oleomargarine; margarite is Greek for pearl, a nod to its luster.","Many brands launched spreads in the 21st century with only one-third of the fat of traditional spreads."],"where":[],"whereNote":null,"sources":[{"title":"Margarine","url":"https://en.wikipedia.org/wiki/Margarine"},{"title":"Hydrogenation","url":"https://en.wikipedia.org/wiki/Hydrogenation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"marker-pen","name":"Marker pen","kind":"product","category":"plastics","title":"How marker pens are made","url":"https://assemblyline.org/make/marker-pen","stations":5,"upstream":45,"downstream":0,"depth":8,"dek":"The tip of a marker pen is a plug of fibers that soaks up ink like a wick.","answer":"A marker's barrel, cap and plugs are injection-molded plastic. A polyester reservoir is dropped into the barrel and filled with ink, and a porous nib is pressed in at the writing end. Ink travels from reservoir to tip by capillary action, the same way a wick draws oil up to a flame.","aka":["felt-tip pen","permanent marker","felt tip"],"inputs":["plastic","polyester","ink"],"uses":[],"grounds":["natural-gas","water","crude-oil","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","coal","limestone","sugar-beet"],"upstreamSlugs":["plastic","polyester","ink","naphtha","natural-gas","ethylene","propylene","pet-plastic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","crude-oil","hydrogen","p-xylene","ethylene-glycol","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","air","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","carbon-dioxide","benzene","methanol","rock-salt","coal","molasses","limestone","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the barrel and cap","process":"mold","text":"Plastic resin is injected into precision molds and cooled to set. Caps and plugs come from the same process.","inputs":["plastic"]},{"name":"Form the nib","process":"mold","text":"Old felt tips were made from a powder mixed with water, molded and baked. Today most nibs are acrylic or polyester fiber, cut or ground to a point or a chisel edge.","inputs":["polyester"]},{"name":"Prepare the ink","process":"mix","text":"Ink is a coloring agent, either dye or pigment, in a liquid carrier. Permanent markers use solvents, and washable markers use water.","inputs":["ink"]},{"name":"Insert the reservoir","process":"assemble","text":"A polyester cylinder, a thick tube of bonded fibers, slides into the barrel. It will hold the ink the way a sponge holds water.","inputs":["polyester"]},{"name":"Fill and fit the nib","process":"fill","text":"Ink is metered in until it saturates the reservoir. The nib goes in, touching the reservoir so ink can reach it, and the cap closes the pen.","inputs":["ink"]}],"facts":["Lee Newman patented a felt-tipped marking pen in 1910, decades before Sidney Rosenthal's Magic Marker of 1953 made the idea popular.","Rosenthal's Magic Marker Corporation went bankrupt in 1980, after rivals made markers that worked on ordinary paper."],"where":[],"whereNote":null,"sources":[{"title":"Marker","url":"https://encyclopedia.com/manufacturing/news-wires-white-papers-and-books/marker"},{"title":"The History, Production, and Future of Markers","url":"https://www.mfgrobots.com/Article/mfg/mpm/2429.html"},{"title":"Felt-tip pen","url":"https://en.wikipedia.org/wiki/Felt-tip_pen"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"marshmallow","name":"Marshmallow","kind":"product","category":"food","title":"How marshmallows are made","url":"https://assemblyline.org/make/marshmallow","stations":6,"upstream":12,"downstream":0,"depth":3,"dek":"A marshmallow is about half air, whipped into hot sugar syrup and trapped by gelatin before it can escape.","answer":"Marshmallows are a foam. Sugar, corn syrup and gelatin are cooked into a syrup, cooled a little, then whipped with compressed air until the mix doubles in volume. The foam is squeezed out as a long rope, cooled until the gelatin sets, chopped into pieces and dusted with starch so the pieces do not stick.","aka":["marshmallows","marshmallow candy"],"inputs":["corn-syrup","sugar","gelatin","water","corn-starch"],"uses":[],"grounds":["water","corn","sugarcane","sugar-beet","pigs","cattle-hide","limestone"],"upstreamSlugs":["corn-syrup","sugar","gelatin","water","corn-starch","corn","sugarcane","sugar-beet","lime","pigs","cattle-hide","limestone"],"downstreamSlugs":[],"steps":[{"name":"Cook gelatin into syrup","process":"cook","text":"Corn syrup, sugar and water are cooked with the gelatin in a fast cooker. Because the syrup spends so little time hot, hardly any gelatin breaks down. A mostly-corn-syrup recipe stays smooth because the mix of sugars resists forming crystals.","inputs":["corn-syrup","sugar","gelatin","water"],"spec":"112–116 °C in 20–30 minutes"},{"name":"Whip in compressed air","process":"mix","text":"The warm syrup passes through an aerator, where pins on a spinning cylinder pass between pins fixed to the wall. Compressed air is injected and the shearing breaks it into countless tiny bubbles.","inputs":[],"spec":"about 50% air"},{"name":"Squeeze out a rope","process":"extrude","text":"A round nozzle lets the foam out of the aerator as a continuous rope. The temperature must stay just above the gelatin's melting point, or the rope slumps and the marshmallows come out oval.","inputs":[]},{"name":"Cool until it sets","process":"chill","text":"The rope travels on a belt through a cooling stretch. As the gelatin cools it forms a net of tangled protein chains that locks the bubbles in place.","inputs":[]},{"name":"Chop to size","process":"cut","text":"Blades slice the set rope into equal pieces. Other lines deposit the foam onto belts for shaped candies, or into starch trays in a mogul.","inputs":[]},{"name":"Dust with starch","process":"coat","text":"Cornstarch is tumbled over the pieces to stop them sticking to each other. They are then sealed in bags.","inputs":["corn-starch"]}],"facts":["The first marshmallows were made by boiling pieces of marsh-mallow root pulp with honey until thick, which is where the candy gets its name.","Alex Doumak patented the extrusion process for marshmallows in 1956.","Gelatin melts at around 95 °F (35 °C), just below body temperature, which gives marshmallows their melt-in-the-mouth feel."],"where":[],"whereNote":null,"sources":[{"title":"Marshmallow","url":"https://en.wikipedia.org/wiki/Marshmallow"},{"title":"Starch mogul","url":"https://en.wikipedia.org/wiki/Starch_mogul"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mascara","name":"Mascara","kind":"product","category":"body-health","title":"How mascara is made","url":"https://assemblyline.org/make/mascara","stations":6,"upstream":32,"downstream":0,"depth":6,"dek":"Mascara is pigment suspended in wax, oil and water, so it clings to lashes and stays flexible.","answer":"Mascara is an emulsion of waxes, oils, pigments and preservatives. Waxes and oils are melted in one vessel, water and thickeners are heated in another, and the two are combined under a high-speed mixer with black pigment. The thick liquid is filled into tubes and a brush is fitted.","aka":["eyelash makeup","lash color"],"inputs":["honeycomb","paraffin-wax","vegetable-oil","water","carbon-black","pigment","nylon","polypropylene"],"uses":[],"grounds":["honeycomb","water","crude-oil","soybeans","rapeseed","clay","air","iron-ore","sulfur","natural-gas","titanium-ore","rock-salt","coal"],"upstreamSlugs":["honeycomb","paraffin-wax","vegetable-oil","water","carbon-black","pigment","nylon","polypropylene","crude-oil","hydrogen","soybeans","rapeseed","hexane","clay","air","iron-ore","titanium-dioxide","sulfur","benzene","nitric-acid","ammonia","propylene","natural-gas","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","naphtha","toluene","rock-salt","coal"],"downstreamSlugs":[],"steps":[{"name":"Melt the wax phase","process":"melt","text":"Beeswax and other waxes are heated with oils until they form a clear liquid. The waxes coat each lash and keep the color on it.","inputs":["honeycomb","paraffin-wax","vegetable-oil"]},{"name":"Prepare the water phase","process":"mix","text":"Water and a thickener are heated in a second tank to the same temperature as the wax phase.","inputs":["water"]},{"name":"Disperse the pigment","process":"grind","text":"Black pigment, typically a carbon black or an iron oxide, is milled until each particle is separated. Clumps would show up as streaks.","inputs":["carbon-black","pigment"]},{"name":"Emulsify the batch","process":"mix","text":"The two phases and the pigment are blended under a high-speed mixer. Droplets of oil and wax end up evenly spread through the water, giving a thick, glossy black paste.","inputs":[]},{"name":"Add the extras","process":"mix","text":"Preservatives go in as the mixture cools. Some formulas also add short fibers of nylon that stick to lashes and make them look longer.","inputs":["nylon"]},{"name":"Fill the tubes","process":"fill","text":"A nozzle fills each tube from the bottom or top. The wand, with its brush end, is pressed into the neck.","inputs":["polypropylene"]}],"facts":["Thomas Lyle Williams made a mascara-like product for his sister Mabel in 1915, and in 1917 it became a mail-order business that grew into Maybelline.","Most mascara formulas share the same basic components: pigments, oils, waxes and preservatives."],"where":[],"whereNote":null,"sources":[{"title":"Mascara","url":"https://en.wikipedia.org/wiki/Mascara"},{"title":"Lipstick","url":"https://en.wikipedia.org/wiki/Lipstick"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"match","name":"Match","kind":"product","category":"wood-paper","title":"How matches are made","url":"https://assemblyline.org/make/match","stations":5,"upstream":35,"downstream":0,"depth":9,"dek":"A safety match will not light on its own box. The chemistry is split between the head and the strip on the side.","answer":"A match is a wooden splint with a chemical head. Factories cut thin splints, soak them in paraffin so they burn evenly, and dip the tips in a paste that holds oxidizing and fuel chemicals. The reactive ingredients are split between the head and a rough strip on the box, so a safety match only lights when scraped on that strip.","aka":["safety match","matchstick","matchbook"],"inputs":["lumber","paraffin-wax","sulfur","cardboard","adhesive"],"uses":[],"grounds":["sulfur","timber","crude-oil","water","natural-gas","rock-salt","limestone","air","coal"],"upstreamSlugs":["lumber","paraffin-wax","sulfur","cardboard","adhesive","timber","crude-oil","hydrogen","wood-pulp","water","polyethylene","acrylic","epoxy","polyurethane","natural-gas","caustic-soda","lime","oxygen","hydrogen-peroxide","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","rock-salt","limestone","air","naphtha","benzene","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Cut thin splints","process":"cut","text":"Wood is sliced into thin sticks. Early mass-production matches were made from wooden blocks with cuts separating the splints, or from combs of splints that were broken off when needed.","inputs":["lumber"]},{"name":"Soak in paraffin","process":"coat","text":"Splints were once soaked in sulfur. Safety matches switched to paraffin, which keeps the flame burning steadily and improves the smell.","inputs":["paraffin-wax"]},{"name":"Dip the heads","process":"coat","text":"One end of each splint is dipped into a paste that dries into a hard head. The head carries an oxidizer and fuel, together with starch and a little sulfur to bind and burn it. In a true safety match the part of the chemistry that ignites easily is kept off the head altogether.","inputs":["sulfur"]},{"name":"Coat the striking strip","process":"coat","text":"A rough strip containing abrasive material and red phosphorus is applied to the side of the box. The two halves of the reaction meet only when the head is dragged across it. Red phosphorus replaced the poisonous white form that crippled early match workers.","inputs":["cardboard","adhesive"]},{"name":"Pack into boxes","process":"package","text":"Matches are counted into sliding boxes or folded into paper books, with the striking surface on the outside of the package.","inputs":[]}],"facts":["The first commercially successful friction match was invented by English pharmacist John Walker, with a sale first recorded on 7 April 1827.","The idea of putting red phosphorus on a separate striking surface was patented in 1844 by the Swede Gustaf Erik Pasch.","White phosphorus matches caused a bone disease called phossy jaw in factory workers, and Finland banned them in 1872."],"where":[],"whereNote":null,"sources":[{"title":"Match","url":"https://en.wikipedia.org/wiki/Match"},{"title":"Lumber","url":"https://en.wikipedia.org/wiki/Lumber"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"matcha","name":"Matcha","kind":"product","category":"drink","title":"How matcha is made","url":"https://assemblyline.org/make/matcha","stations":5,"upstream":1,"downstream":0,"depth":1,"dek":"The tea bushes are kept in the shade for weeks before picking, which keeps the umami and holds back the bitterness.","answer":"Matcha is a fine green powder made from tea plants shaded for 2 to 3 weeks before harvest. The picked leaves are steamed, dried flat without rolling to become tencha, and ground to a powder, traditionally in a stone mill. The shading stops the leaf from turning its umami amino acid into bitter tannins.","aka":["powdered green tea","ceremonial tea"],"inputs":["tea-leaves"],"uses":[],"grounds":["tea-leaves"],"upstreamSlugs":["tea-leaves"],"downstreamSlugs":[],"steps":[{"name":"Shade the bushes","process":"grow","text":"Japanese labeling standards require the tea plants to be covered for 2 to 3 weeks before harvest. Less sunlight slows photosynthesis, so theanine, which carries the umami flavor, is not converted into bitter tannins.","inputs":[],"spec":"2 to 3 weeks of shade"},{"name":"Pick the young leaves","process":"harvest","text":"The shaded leaves, which are bright green, are picked. Japanese standards allow matcha to be made only from leaves.","inputs":["tea-leaves"]},{"name":"Steam the leaves","process":"cook","text":"Steaming stops the leaf from oxidizing and darkening, which locks in the vivid green color.","inputs":[]},{"name":"Dry them flat","process":"dry","text":"The steamed leaves are dried without being rolled. The result is called tencha, which is leaf tea that has not yet been ground.","inputs":[]},{"name":"Mill to powder","process":"grind","text":"Tencha is ground to a fine powder. A stone mill specialized for tea appeared in Japan in the 14th century and produced finer powder than the earlier grinders.","inputs":[]}],"facts":["The monk Myoan Eisai presented a book on drinking tea to a shogun in 1214.","Cheaper powdered tea made from unshaded leaves is sold as matcha for flavoring foods, but does not meet the definition.","Matcha's powder form goes back to Tang dynasty China, where tea was pounded and milled into fine powder and pressed into cakes."],"where":[],"whereNote":null,"sources":[{"title":"Matcha","url":"https://en.wikipedia.org/wiki/Matcha"},{"title":"Green tea","url":"https://en.wikipedia.org/wiki/Green_tea"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mattress","name":"Mattress","kind":"product","category":"textiles","title":"How mattresses are made","url":"https://assemblyline.org/make/mattress","stations":6,"upstream":57,"downstream":0,"depth":8,"dek":"The coil spring inside most mattresses was adapted from carriage seat springs of the 19th century.","answer":"Most mattresses sold in North America are innersprings. Steel wire is coiled into springs, which are linked into a single unit. Layers of foam or fiber are placed above and below to cushion the sleeper, and a quilted fabric cover called ticking is stitched around everything. The cover is closed and the mattress is packed.","aka":["innerspring mattress","foam mattress","bed mattress"],"inputs":["steel-wire","polyurethane","adhesive","polyester","thread"],"uses":[],"grounds":["water","crude-oil","air","rock-salt","iron-ore","limestone","dolomite","manganese-ore","natural-gas","sulfur","coal","quartz","timber","corn","sugarcane","sugar-beet"],"upstreamSlugs":["steel-wire","polyurethane","adhesive","polyester","thread","steel","propylene","nitric-acid","chlorine","water","polyethylene","acrylic","epoxy","paraffin-wax","pet-plastic","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","naphtha","crude-oil","ammonia","air","rock-salt","sulfuric-acid","ethylene","methanol","phenol","acetone","caustic-soda","hydrogen","p-xylene","ethylene-glycol","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","sulfur","benzene","carbon-dioxide","coal","quartz","charcoal","timber","toluene","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Coil the wire","process":"stamp","text":"Machines bend steel wire into hourglass-shaped coils. Thicker wire makes a firmer spring, and 14-gauge wire at 1.63 mm is typical of higher-quality coils. The oldest and most common type is the Bonnell coil, a knotted, round-top coil.","inputs":["steel-wire"]},{"name":"Lace into a spring unit","process":"assemble","text":"Rows of coils are linked together by interconnecting wires or hinged with helical wires. The connections help the mattress hold its shape. Pocket springs skip the wires and are instead sewn into individual fabric sleeves.","inputs":[]},{"name":"Pour the comfort foam","process":"mold","text":"Flexible polyurethane foam is poured, cured and sliced into sheets, including bumpy egg-crate foam, for the comfort layers. Some mattresses use latex or memory foam here.","inputs":["polyurethane"]},{"name":"Stack the layers","process":"laminate","text":"A fiber or mesh insulator goes over the springs to keep the padding from sinking in. The padding goes on next, then a quilt of light foam or fiber.","inputs":["adhesive"]},{"name":"Quilt the cover","process":"sew","text":"Ticking, the protective fabric cover, is stitched to a thin layer of foam or fiber to make a soft quilted top. The fabric can be knit, damask or printed woven.","inputs":["polyester","thread"]},{"name":"Close it up","process":"sew","text":"The cover is sewn around the finished core and padding, and the edges are bound with a border. The mattress is then wrapped for delivery.","inputs":["thread"]}],"facts":["The word mattress comes from an Arabic word meaning something thrown down.","Early mattresses were stuffed with straw, feathers or horsehair.","In the first half of the 20th century, a typical mattress sold in North America had an innerspring core and cotton batting or fiberfill."],"where":[],"whereNote":null,"sources":[{"title":"Mattress","url":"https://en.wikipedia.org/wiki/Mattress"},{"title":"Sewing thread","url":"https://en.wikipedia.org/wiki/Sewing_thread"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mayonnaise","name":"Mayonnaise","kind":"product","category":"food","title":"How mayonnaise is made","url":"https://assemblyline.org/make/mayonnaise","stations":6,"upstream":38,"downstream":0,"depth":8,"dek":"A jar of mayonnaise is mostly oil, held in tiny droplets by the lecithin in a little egg yolk.","answer":"Mayonnaise lives or dies on droplet size. Factories start from a water phase with egg yolk, then inject oil into a high-intensity mixer, often a rotor-stator mixer or a colloid mill, which tears it into tiny droplets that the yolk coats. Smaller droplets make it thicker, whiter and milder tasting. Too much shear thins the batch or breaks it.","aka":["mayo","salad dressing"],"inputs":["eggs","water","table-salt","sugar","mustard","vinegar","vegetable-oil"],"uses":[],"grounds":["eggs","water","rock-salt","seawater","sugarcane","sugar-beet","mustard-seed","grapes","soybeans","rapeseed","clay","limestone","corn","barley","crude-oil","silica-sand","natural-gas","trona","air"],"upstreamSlugs":["eggs","water","table-salt","sugar","mustard","vinegar","vegetable-oil","rock-salt","seawater","sugarcane","sugar-beet","lime","mustard-seed","glass-jar","grapes","ethanol","malted-barley","yeast","soybeans","rapeseed","hexane","clay","limestone","glass","corn","ethylene","barley","molasses","crude-oil","hydrogen","silica-sand","soda-ash","naphtha","natural-gas","ammonia","carbon-dioxide","trona","air"],"downstreamSlugs":[],"steps":[{"name":"Disperse yolk in water","process":"mix","text":"Egg yolk goes into water in the mixing vessel. It works as both emulsifier and texturizer, so more yolk gives a thicker product with smaller droplets.","inputs":["eggs","water"]},{"name":"Add seasonings","process":"mix","text":"Salt, sugar, mustard and vinegar join the water phase. The blend can run in batches or continuously, depending on how the plant combines its mixers and tanks.","inputs":["table-salt","sugar","mustard","vinegar"]},{"name":"Inject cooled oil","process":"mix","text":"Oil is metered into the vessel under strong agitation. Starting with cooled oil gives a firmer texture, and good flow in the vessel lets it go in faster without hurting quality or stretching the mixing time.","inputs":["vegetable-oil"]},{"name":"Shear the droplets small","process":"mix","text":"A high-speed rotor-stator mixer or colloid mill pours its energy into a tiny volume of product, ripping oil droplets apart. Smaller droplets scatter light differently too, which is why fine mayonnaise looks whiter.","inputs":[]},{"name":"Mill at the discharge","process":"grind","text":"An inline mill at the outlet of the batch tank gives the emulsion its final shear. Too little or too much leaves it thin, and too much can split it, so operators adjust the mill gap or speed with care.","inputs":[]},{"name":"Check, fill and seal","process":"fill","text":"Each batch is checked by a taste panel and by lab instruments that measure texture, yield stress and viscosity. A jar of the finished product holds its shape until stirred. It is then pumped into jars or bottles and sealed.","inputs":[]}],"facts":["Mayonnaise is thought to come from Mahon in Menorca, during the French occupation in the Seven Years' War.","In 1815 the chef Antonin Carême wrote of a cold magnonaise emulsified with egg yolk, the same year the word mayonnaise is first attested in English."],"where":[],"whereNote":null,"sources":[{"title":"Tetra Pak: How to achieve high-quality mayonnaise","url":"https://processinginsights.tetrapak.com/high-quality-mayonnaise-processing/"},{"title":"Admix: Addressing mayonnaise processing inconsistencies","url":"https://media.admix.com/mayo-processing"},{"title":"Mayonnaise","url":"https://en.wikipedia.org/wiki/Mayonnaise"},{"title":"Vinegar","url":"https://en.wikipedia.org/wiki/Vinegar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mdf","name":"MDF","kind":"material","category":"wood-paper","title":"How MDF is made","url":"https://assemblyline.org/make/mdf","stations":7,"upstream":28,"downstream":3,"depth":8,"dek":"MDF is wood torn into single fibers, then blown through a pipe that widens from 40 mm to 1,500 mm.","answer":"Medium-density fiberboard is wood broken all the way down into fibers, then pressed back together. Chips are steamed soft, torn apart between grooved spinning discs, mixed with wax and resin in a fast-moving pipe, formed into a thick mat and squeezed in a hot press. The result is a smooth, grainless panel.","aka":["medium-density fibreboard","fiberboard"],"inputs":["timber","paraffin-wax","adhesive"],"uses":["sofa","treadmill","loudspeaker"],"grounds":["timber","crude-oil","water","natural-gas","air","sulfur","rock-salt","coal"],"upstreamSlugs":["timber","paraffin-wax","adhesive","crude-oil","hydrogen","polyethylene","acrylic","epoxy","polyurethane","water","natural-gas","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","naphtha","air","sulfur","benzene","rock-salt","toluene","coal"],"downstreamSlugs":["sofa","treadmill","loudspeaker"],"steps":[{"name":"Chip the logs","process":"cut","text":"Logs are debarked and fed to a chipper with a ring of blades. Sawmill leftovers and thinnings work too. The chips are washed and checked for defects.","inputs":["timber"]},{"name":"Steam the chips soft","process":"cook","text":"A screw feeder packs the chips into plugs, which are heated so the natural glue holding the wood fibers together turns soft.","inputs":[],"spec":"30 to 120 seconds"},{"name":"Tear them into fibers","process":"crush","text":"Softened chips are fed into the center of two counter-rotating discs with grooves in their faces. Centrifugal force carries them outward, and the grooves, which get finer toward the edge, pull the chips apart into individual fibers.","inputs":[]},{"name":"Blow in wax and resin","process":"mix","text":"The fibers shoot into a pipe that widens from 40 mm to 1500 mm. Wax is sprayed in first to help the board resist moisture, then a resin glue. The fibers dry on the way out and expand into a light, fluffy cloud.","inputs":["paraffin-wax","adhesive"]},{"name":"Lay down the mat","process":"mold","text":"The dry fibers are sucked into a machine that spreads them into an even mat, hundreds of millimeters thick. The mat is lightly compressed so it can move on.","inputs":[]},{"name":"Press under heat","process":"press","text":"A hot press cures the resin and squeezes the mat in stages. The two faces end up denser than the core, which gives the board its strength and a hard, smooth surface.","inputs":[]},{"name":"Cool, trim and sand","process":"grind","text":"Boards cool in a rotating rack, are trimmed to size and are sanded smooth. Some are laminated afterward for extra strength.","inputs":[]}],"facts":["A typical MDF panel is about 82 percent wood fiber, 9 percent glue, 8 percent water and 1 percent wax.","Large-scale MDF production only began in the 1980s, in both North America and Europe.","MDF has no grain, so a veneer glued to it will not show a texture telegraphing through from below."],"where":[],"whereNote":null,"sources":[{"title":"Medium-density fibreboard","url":"https://en.wikipedia.org/wiki/Medium-density_fibreboard"},{"title":"Pulp (paper)","url":"https://en.wikipedia.org/wiki/Pulp_(paper)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mead","name":"Mead","kind":"product","category":"drink","title":"How mead is made","url":"https://assemblyline.org/make/mead","stations":5,"upstream":24,"downstream":0,"depth":6,"dek":"Mead may be the oldest alcoholic drink, and it needs nothing but honey, water and yeast.","answer":"Mead is made by mixing honey with water and fermenting it with a yeast like the ones used for white wine. The first fermentation takes 28 to 56 days. The liquid is then moved off the dead yeast and aged for six to nine months. The finished drink ranges from about 3.5 to more than 20 percent alcohol.","aka":["honey wine","hydromel"],"inputs":["honey","water","yeast","glass-bottle"],"uses":[],"grounds":["water","honeycomb","silica-sand","limestone","sugarcane","sugar-beet","rock-salt","trona","natural-gas","air","corn","crude-oil"],"upstreamSlugs":["honey","water","yeast","glass-bottle","honeycomb","molasses","silica-sand","soda-ash","limestone","polyethylene","sugarcane","sugar-beet","rock-salt","ammonia","carbon-dioxide","lime","trona","ethylene","natural-gas","air","corn","naphtha","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Thin the honey","process":"mix","text":"Honey is mixed with water, and sometimes fruit, spices, grains or hops. The sugars in the honey are what the yeast will feed on, and the added water sets how strong the mead can get.","inputs":["honey","water"]},{"name":"Add the yeast","process":"ferment","text":"Mead ferments at about the same temperatures as wine, often with wine yeast. A hydrometer or refractometer tracks the sugar left, and from it the alcohol.","inputs":["yeast"],"spec":"28 to 56 days"},{"name":"Rack off the lees","process":"separate","text":"The mead is drawn off the dead yeast cells at the bottom, called lees, into a clean container for a second fermentation.","inputs":[]},{"name":"Age the mead","process":"dry","text":"In the second vessel the mead rests for six to nine months. Length varies with the honey, water content, acidity and yeast strain.","inputs":[],"spec":"6 to 9 months"},{"name":"Bottle it","process":"fill","text":"Some meads keep the sweetness of the honey and are served as dessert wines, others are bottled dry or sparkling.","inputs":["glass-bottle"]}],"facts":["A mead with fruit is called a melomel, one with spices is a metheglin, and one made with grape juice is a pyment.","Mead may have been discovered 20,000 to 40,000 years ago, before farming and pottery.","Mead's name comes from Old English meodu, related to Sanskrit madhu."],"where":[],"whereNote":null,"sources":[{"title":"Mead","url":"https://en.wikipedia.org/wiki/Mead"},{"title":"Honey","url":"https://en.wikipedia.org/wiki/Honey"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wristwatch","name":"Mechanical wristwatch","kind":"product","category":"machines","title":"How mechanical wristwatches are made","url":"https://assemblyline.org/make/wristwatch","stations":6,"upstream":58,"downstream":0,"depth":7,"dek":"A watch's balance wheel swings up to ten times a second, and every swing lets the gears advance one step.","answer":"A mechanical wristwatch movement has five parts: a mainspring that stores energy, a gear train, a balance wheel that oscillates, an escapement that releases the gears one step at a time, and a winding mechanism. Makers machine and finish these parts, assemble the movement by hand, regulate it, then fit it in a case.","aka":["watch","mechanical watch","automatic watch"],"inputs":["brass","steel","stainless-steel","glass","leather"],"uses":[],"grounds":["silica-sand","limestone","cattle-hide","rock-salt","water","copper-ore","air","zinc-ore","lead-ore","tin-ore","crude-oil","coal","iron-ore","dolomite","manganese-ore","natural-gas","chromite","nickel-ore","trona","sulfur","bauxite","quartz","timber","corn","sugarcane","sugar-beet"],"upstreamSlugs":["brass","steel","stainless-steel","glass","leather","copper","zinc","lead","tin","aluminum","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","chromium","nickel","silica-sand","soda-ash","limestone","cattle-hide","rock-salt","water","copper-ore","air","sulfuric-acid","zinc-ore","lead-ore","coke","tin-ore","crude-oil","coal","petroleum-coke","alumina","iron-ore","dolomite","silicon","propane","manganese-ore","natural-gas","chromite","nickel-ore","ammonia","carbon-dioxide","trona","sulfur","bauxite","caustic-soda","quartz","charcoal","timber","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Machine the plates and gears","process":"machine","text":"Brass and steel are machined into the plates, wheels and pinions of the gear train. This train carries the force of the mainspring to the balance wheel and counts its swings into seconds, minutes and hours.","inputs":["brass","steel"]},{"name":"Make the mainspring","process":"roll","text":"A long thin strip of spring steel is wound into a barrel. It stores the mechanical energy that runs the watch.","inputs":["steel"]},{"name":"Build the escapement","process":"grind","text":"The escape wheel and pallets are ground and polished. At each swing of the balance, the escapement lets the gears advance a set amount, and that stop-start action is the ticking sound.","inputs":[]},{"name":"Assemble the movement","process":"assemble","text":"Watchmakers fit every part into the plates, oil the pivots and bring the movement to life. A self-winding watch adds a rotating weight that winds the spring as the wrist moves.","inputs":[]},{"name":"Regulate the rate","process":"inspect","text":"A regulator lever on the balance spring is moved until the movement keeps accurate time in several positions, because the swings of the balance wheel set the pace.","inputs":[]},{"name":"Case, dial and hands","process":"assemble","text":"The movement is placed in a case with a dial, hands and crystal, and fitted with a strap.","inputs":["stainless-steel","glass","leather"]}],"facts":["Most watch balance wheels oscillate at 5, 6, 8 or 10 beats per second, which is 18,000 to 36,000 beats per hour.","A tourbillon is a rotating cage around the balance wheel that was meant to cancel out the pull of gravity in a pocket watch."],"where":[],"whereNote":null,"sources":[{"title":"Mechanical watch","url":"https://en.wikipedia.org/wiki/Mechanical_watch"},{"title":"Watch","url":"https://en.wikipedia.org/wiki/Watch"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"melamine-resin","name":"Melamine resin","kind":"material","category":"plastics","title":"How melamine resin is made","url":"https://assemblyline.org/make/melamine-resin","stations":6,"upstream":13,"downstream":1,"depth":4,"dek":"That hard, glossy plate and the Formica counter come from urea and formaldehyde. So does the Magic Eraser.","answer":"Molten urea turns into melamine, a ring-shaped molecule that is 66% nitrogen. Reacted with formaldehyde, it gives a syrupy resin that sets permanently under heat and pressure. Paper soaked in it becomes the top skin of laminate flooring and countertops, and powder pressed in a hot mold becomes tableware, one of the hardest plastics made.","aka":["melamine formaldehyde","melamine","Formica resin","MF resin"],"inputs":["ammonia","carbon-dioxide","formaldehyde"],"uses":["laminate-floor"],"grounds":["natural-gas","water","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["ammonia","carbon-dioxide","formaldehyde","natural-gas","water","air","corn","yeast","limestone","methanol","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["laminate-floor"],"steps":[{"name":"Make the urea","process":"react","text":"Ammonia and carbon dioxide combine into urea. Melamine plants are often built alongside urea plants because of the feedstock and the gases they hand back.","inputs":["ammonia","carbon-dioxide"]},{"name":"Turn urea into rings","process":"react","text":"Molten urea goes onto a fluidized bed of catalyst, kept moving by hot ammonia gas, or into a high-pressure liquid reactor. Six molecules of urea give one of melamine, and the waste gases return to the urea plant.","inputs":[]},{"name":"Crystallize the white solid","process":"chill","text":"The output is cooled, and off-gas is separated from a melamine-rich slurry. That slurry is concentrated and crystallized into a white solid.","inputs":[]},{"name":"Condense with formaldehyde","process":"react","text":"Formaldehyde attaches to the melamine rings, up to six at a time ideally. The result is a resin that can still flow. Further heating with acid would link it up permanently, so the reaction is stopped short.","inputs":["formaldehyde"]},{"name":"Saturate paper or dry powder","process":"coat","text":"Decorative paper is soaked in the liquid resin for laminates. Other batches become powder for molding or stay liquid as adhesive for particle board.","inputs":[]},{"name":"Press it hard with heat","process":"press","text":"Heat and high pressure in a press or closed mold cross-link the molecules into one network. After this it cannot melt again. Cross-link density can be tuned by mixing in related molecules such as benzoguanamine.","inputs":[]}],"facts":["Molded plates and food containers switched from urea resin to this one beginning in the 1950s, because it resists moisture better and is harder.","The foam sold as the Magic Eraser is a special form of the same resin.","Farmers were once expected to use melamine as fertilizer because of its 66% nitrogen, but it cost too much to produce."],"where":[],"whereNote":null,"sources":[{"title":"Melamine resin","url":"https://en.wikipedia.org/wiki/Melamine_resin"},{"title":"Melamine","url":"https://en.wikipedia.org/wiki/Melamine"},{"title":"Melamine-formaldehyde resin (Britannica)","url":"https://www.britannica.com/science/melamine-formaldehyde-resin"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"memory-chip","name":"Memory chip","kind":"product","category":"electronics","title":"How memory chips are made","url":"https://assemblyline.org/make/memory-chip","stations":7,"upstream":33,"downstream":8,"depth":8,"dek":"Each bit of DRAM is one transistor and one tiny capacitor, and the capacitor leaks, so it is refilled constantly.","answer":"Memory chips are made on silicon wafers with the same layered lithography as processors, but the pattern is a vast repeating grid of cells. DRAM cells hold a charge in a microscopic capacitor. Flash cells trap electrons in an insulating layer, and 3D flash stacks those layers vertically before dies are tested, sawed and stacked in a package.","aka":["RAM chip","DRAM","NAND flash","flash memory chip"],"inputs":["silicon-wafer","nitrogen","photoresist","copper"],"uses":["smartphone","laptop","solid-state-drive","smartwatch","digital-camera","game-console","wifi-router","graphics-card"],"grounds":["quartz","air","copper-ore","water","sulfur","coal","timber","natural-gas","rock-salt","crude-oil"],"upstreamSlugs":["silicon-wafer","nitrogen","photoresist","copper","polysilicon","quartz","argon","air","phenolic-resin","copper-ore","water","oxygen","sulfuric-acid","silicon","hydrochloric-acid","trichlorosilane","hydrogen","phenol","formaldehyde","sulfur","coke","coal","charcoal","timber","chlorine","natural-gas","benzene","propylene","methanol","rock-salt","naphtha","toluene","crude-oil"],"downstreamSlugs":["smartphone","laptop","solid-state-drive","smartwatch","digital-camera","game-console","wifi-router","graphics-card"],"steps":[{"name":"Prepare the wafer","process":"heat-treat","text":"Polished wafers are oxidized and prepared in the same cleanroom flow used for any chip, with wafers moving in sealed nitrogen-filled boxes.","inputs":["silicon-wafer","nitrogen"]},{"name":"Print the cell grid","process":"etch","text":"Light patterns a repeating array of cells across each die. A DRAM cell needs only a transistor and a microscopic capacitor, while a static memory cell needs four or six transistors, which is why DRAM packs so densely.","inputs":["photoresist"]},{"name":"Build up the stack","process":"deposit","text":"In charge-trap flash, a silicon nitride layer replaces the floating gate and traps electrons. In 3D NAND the cells are stacked vertically. Samsung's first device in 2013 had 24 layers, and later dies went well past that.","inputs":[]},{"name":"Wire the cells together","process":"deposit","text":"Metal lines are deposited and etched on top to reach every row and column of cells.","inputs":["copper"]},{"name":"Test the wafer","process":"inspect","text":"Automatic test equipment checks each die before it is cut out of the wafer.","inputs":[]},{"name":"Stack the dies","process":"assemble","text":"Good dies are cut out and piled in a package, linked by through-silicon vias. A package with 16 stacked dies and a separate controller die can hold up to 1 tebibyte.","inputs":[]},{"name":"Test the finished part","process":"inspect","text":"The packaged chip is run through final tests on equipment like that used at wafer probe.","inputs":[]}],"facts":["A DRAM capacitor loses its charge gradually, so a refresh circuit must rewrite every bit again and again, which is what the word dynamic means.","Only three major suppliers (Micron Technology, SK Hynix and Samsung Electronics) dominated DRAM in 2018.","Toshiba announced 3D flash in 2007, and Samsung shipped the first stacked V-NAND device in 2013."],"where":[],"whereNote":null,"sources":[{"title":"Flash memory","url":"https://en.wikipedia.org/wiki/Flash_memory"},{"title":"Dynamic random-access memory","url":"https://en.wikipedia.org/wiki/Dynamic_random-access_memory"},{"title":"Semiconductor device fabrication","url":"https://en.wikipedia.org/wiki/Semiconductor_device_fabrication"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mercury","name":"Mercury","kind":"material","category":"metals","title":"How mercury is made","url":"https://assemblyline.org/make/mercury","stations":5,"upstream":2,"downstream":1,"depth":1,"dek":"Roast a soft red rock in moving air, chill what comes off, and a metal that stays liquid at room temperature runs out.","answer":"Even the richest ore holds only 2.5% of this metal, locked up as the red sulfide cinnabar. Plants heat crushed ore in moving air, so oxygen takes the sulfur and the freed metal rises as vapor. A cooled column turns that vapor into liquid, distillation cleans it, and it ships in iron flasks.","aka":["quicksilver","Hg"],"inputs":["cinnabar","air"],"uses":["neon-sign"],"grounds":["cinnabar","air"],"upstreamSlugs":["cinnabar","air"],"downstreamSlugs":["neon-sign"],"steps":[{"name":"Crush the red ore","process":"crush","text":"Ore from the mine is broken small so heat and air can reach the cinnabar inside it. Cinnabar is soft, with a Mohs hardness of 2 to 2.5, and grinds readily.","inputs":["cinnabar"]},{"name":"Roast in a rotary furnace","process":"react","text":"The crushed ore tumbles through a rotary furnace in a current of air. Oxygen binds to the sulfur and leaves as sulfur dioxide gas, and the metal evaporates. Spent rock comes out as calcines, and runoff from abandoned calcine piles is a recognized source of ecological damage.","inputs":["air"]},{"name":"Condense the vapor","process":"chill","text":"Hot furnace gas climbs into a condensing column, where the metal cools from vapor back to liquid. Refining this metal is hazardous work and a historic cause of poisoning.","inputs":[]},{"name":"Distill out impurities","process":"refine","text":"The collected liquid is heated again and purified by distillation. Different substances boil at different temperatures, so the metal comes off apart from whatever it dragged along.","inputs":[]},{"name":"Fill iron flasks","process":"fill","text":"Finished metal is most often shipped in iron flasks. It forms amalgams with almost every common metal, and iron is the exception. Prices are quoted by the flask.","inputs":[],"spec":"76 pounds to a flask"}],"facts":["Mercury became the first known superconductor in 1911, when it was chilled below 4 K.","The mines at Almadén in Spain have produced about 250,000 metric tons of mercury over the past 2000 years.","Nevada's McDermitt Mine, the last mercury mine in the United States, closed in 1992."],"where":[{"place":"China","share":"88% of world output, 2200 tonnes"},{"place":"Tajikistan","share":"178 tonnes"},{"place":"Russia","share":"50 tonnes"},{"place":"Mexico","share":"32 tonnes"}],"whereNote":"Mine output in 2020, out of about 2500 tonnes worldwide, as given on Wikipedia.","sources":[{"title":"Mercury (element)","url":"https://en.wikipedia.org/wiki/Mercury_(element)"},{"title":"Cinnabar","url":"https://en.wikipedia.org/wiki/Cinnabar"},{"title":"Mercury, Chemistry Explained","url":"https://www.chemistryexplained.com/elements/L-P/Mercury.html"},{"title":"Mercury Statistics and Information, USGS","url":"https://www.usgs.gov/centers/national-minerals-information-center/mercury-statistics-and-information"},{"title":"Almadén","url":"https://en.wikipedia.org/wiki/Almad%C3%A9n"},{"title":"Cinnabar, Geology.com","url":"https://geology.com/minerals/cinnabar.shtml"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"silicon","name":"Metallurgical silicon","kind":"material","category":"electronics","title":"How metallurgical silicon is made","url":"https://assemblyline.org/make/silicon","stations":8,"upstream":5,"downstream":191,"depth":2,"dek":"Silicon smelters guard their carbon balance, because too much carbon fills the furnace hearth with silicon carbide.","answer":"Metallurgical silicon comes from smelting quartz with coke, coal, charcoal and wood chips in a submerged arc furnace, near 2000 °C at the electrode tip. Carbon strips the oxygen and leaves liquid silicon. It is tapped into a ladle, purged with an air-oxygen mix to drive calcium and aluminum into slag, then cast and crushed. Most of this grade goes into aluminum alloys.","aka":["silicon metal","metallurgical grade silicon","MG-Si"],"inputs":["quartz","coke","coal","charcoal","timber"],"uses":["silicone","polysilicon","magnesium","trichlorosilane"],"grounds":["quartz","coal","timber"],"upstreamSlugs":["quartz","coke","coal","charcoal","timber"],"downstreamSlugs":["silicone","polysilicon","magnesium","trichlorosilane","shampoo","deodorant","syringe","condom","hearing-aid","solar-panel","contact-lens","airbag","cork-stopper","pressure-cooker","blender","foundation-makeup","eyeshadow","prosthetic-leg","double-glazed-window","remote-control","electric-toothbrush","silicon-wafer","steel","titanium","water-heater","toy-car","digital-camera","satellite","car","electric-car","champagne","aluminum-window-frame","microchip","memory-chip","camera-sensor","solar-cell","inkjet-printer","toothbrush","lithium-ion-cell","ev-battery","aa-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","pacemaker","hip-implant","jet-engine","thermometer","credit-card","smartphone","laptop","solid-state-drive","computer-keyboard","computer-mouse","drone","rocket","smartwatch","wireless-earbuds","phone-charger","game-console","wifi-router","e-reader","graphics-card","refrigerator","microwave-oven","washing-machine","air-conditioner","treadmill","safety-pin","ceiling-fan","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","concrete","skyscraper","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sailboat","action-figure","power-outlet","electric-kettle","pencil","mirror","golf-ball","wallpaper","wooden-chair","water-bottle","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","snow-globe","neon-sign","toffee"],"steps":[{"name":"Size the quartz","process":"crush","text":"Quartz or quartzite goes through crushers and is screened to lumps of a set size, since the furnace charge needs to stay porous.","inputs":["quartz"]},{"name":"Charge the furnace","process":"mix","text":"Crushed quartz goes in with a blend of reductants: coke, coal, charcoal and wood chips. Charcoal reacts readily, coal can bring in iron that ends up in the metal, and fine petroleum coke can blow straight out with the furnace gas.","inputs":["quartz","coke","coal","charcoal","timber"]},{"name":"Smelt in an arc","process":"melt","text":"Electrodes run down into the charge. Near their tips the carbon pulls oxygen from the silica, through silicon monoxide gas and silicon carbide, and liquid silicon collects below. Operators keep silica in excess so silicon carbide does not pile up.","inputs":[],"spec":"about 2000 °C near the electrode"},{"name":"Tap into a ladle","process":"cast","text":"Liquid metal runs from the furnace directly into a ladle. Refining often starts here, as the tap jet drags air into the melt.","inputs":[]},{"name":"Blow the ladle","process":"refine","text":"An air-oxygen mix is purged through the melt. Silica forms on the bubbles, reacts with calcium and aluminum impurities, and carries them off into a slag.","inputs":[]},{"name":"Cast into molds","process":"cast","text":"Refined silicon is poured into molds, then cooled until solid.","inputs":[]},{"name":"Crush and size","process":"crush","text":"The ingots are crushed, sized and packaged for buyers.","inputs":[]},{"name":"Sort by purity grade","process":"inspect","text":"Output is sorted by purity. Grades of 95 to 99% count as metallurgical silicon, and a share goes on to be purified for semiconductors.","inputs":[]}],"facts":["Most elemental silicon never leaves the steel industry as ferrosilicon, and only about 20% is refined to metallurgical-grade purity.","About 55% of metallurgical-grade silicon goes into aluminum-silicon alloys, mainly for cast car parts.","Only an estimated 15% of metallurgical-grade silicon is refined further to semiconductor purity."],"where":[],"whereNote":null,"sources":[{"title":"Silicon","url":"https://en.wikipedia.org/wiki/Silicon"},{"title":"Polysilicon","url":"https://en.wikipedia.org/wiki/Polysilicon"},{"title":"Production of metallurgical-grade silicon from Egyptian quartz, Journal of the SAIMM","url":"https://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532018000200011"},{"title":"Refining Kinetics of Selected Elements in the Industrial Silicon Process, Metallurgical and Materials Transactions B","url":"https://link.springer.com/article/10.1007/s11663-015-0305-2"},{"title":"Silicon metal manufacturing process, KXG Alloy","url":"https://www.kxgalloy.com/info/silicon-metal-manufacturing-process-81969158.html"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"methanol","name":"Methanol","kind":"material","category":"chemicals","title":"How methanol is made","url":"https://assemblyline.org/make/methanol","stations":5,"upstream":2,"downstream":273,"depth":1,"dek":"Factories make methanol from natural gas over copper, and living plants still give off two to three times as much.","answer":"Methanol plants turn natural gas and steam into synthesis gas, a mix of hydrogen and carbon oxides. That gas flows over a copper-based catalyst in a reactor and comes out as liquid methanol, which is distilled clean. The product becomes formaldehyde, acetic acid and fuel additives. Biodiesel makers use it too.","aka":["methyl alcohol","wood alcohol","CH3OH"],"inputs":["natural-gas","water"],"uses":["acrylic","silicone","glycerin","acetic-anhydride","biodiesel","formaldehyde","polyvinyl-alcohol"],"grounds":["natural-gas","water"],"upstreamSlugs":["natural-gas","water"],"downstreamSlugs":["acrylic","silicone","glycerin","acetic-anhydride","biodiesel","formaldehyde","polyvinyl-alcohol","paint","adhesive","lcd-screen","sunglasses","lacquer","globe","shampoo","deodorant","syringe","condom","hearing-aid","solar-panel","contact-lens","airbag","cork-stopper","pressure-cooker","blender","foundation-makeup","eyeshadow","prosthetic-leg","double-glazed-window","remote-control","electric-toothbrush","soap","toothpaste","sunscreen","chewing-gum","snow-globe","cough-syrup","gelatin-capsule","aspirin","acetaminophen","ibuprofen","cellulose-acetate","diesel","super-glue","billiard-ball","spandex","melamine-resin","phenolic-resin","polyvinylpyrrolidone","pvb","banknote","refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","scissors","mirror","car","electric-car","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","golf-ball","wallpaper","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","dartboard","dice","action-figure","fashion-doll","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","adhesive-bandage","credit-card","duct-tape","led-bulb","ev-battery","nail","insulation","popcorn","windshield","skateboard","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","door","pencil-eraser","clear-tape","staple","sofa","ski","snowboard","ice-skates","volleyball","cricket-bat","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","sailboat","dress-shirt","suit","raincoat","handbag","suitcase","wallet","flip-flops","hiking-boots","high-heels","smartwatch","wireless-earbuds","loudspeaker","microphone","camera-lens","e-reader","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","sneaker","leather-shoe","baseball-cap","carpet","mattress","diaper","laptop","television","digital-camera","tin-can","electric-guitar","trumpet","chopsticks","saxophone","felt-hat","vinyl-record","compact-disc","baseball-bat","satellite","champagne","shoelace","underwear","leggings","swimsuit","ink","photoresist","hairspray","padlock","dishwasher","treadmill","toothbrush","fireworks","plastic-wrap","trading-cards","cake-mix","soda","energy-drink","hair-dye","tampon","detergent","plastic-bag","nitrile-glove","vacuum-cleaner","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","light-switch","smoke-detector","game-console","wifi-router","facial-tissue","condensed-milk","baby-formula","coconut-milk","canned-soup","aluminum-can","soccer-ball","ballpoint-pen","paper-cup","marker-pen","highlighter","frisbee","candy-coated-chocolate","floor-tile","vinyl-floor","flag","inkjet-printer","newspaper","t-shirt","umbrella","microchip","memory-chip","printed-circuit-board","indium-tin-oxide","aa-battery","candy-cane","toffee","cola","sparkling-water","beer","hard-cider","root-beer","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","pacemaker","thermometer","smartphone","solid-state-drive","computer-keyboard","computer-mouse","drone","rocket","phone-charger","usb-cable","graphics-card","hard-drive","wind-turbine","elevator","oled-screen","skyscraper"],"steps":[{"name":"Reform gas into syngas","process":"react","text":"Natural gas and steam react over a catalyst to give synthesis gas, a mixture of hydrogen and carbon monoxide. The plant is built around this step.","inputs":["natural-gas","water"]},{"name":"Pass it over copper","process":"react","text":"Compressed synthesis gas flows through a reactor packed with a copper-based catalyst. Modern catalysts allow much gentler conditions than the extreme pressures of the first synthetic process.","inputs":[]},{"name":"Condense the crude liquid","process":"chill","text":"The gas leaving the reactor is cooled until the methanol condenses. Unreacted gas loops back to the reactor for another pass.","inputs":[]},{"name":"Distill it clean","process":"refine","text":"Distillation columns strip off water and lighter by-products. The finished methanol is a clear liquid shipped in tankers.","inputs":[]},{"name":"Send it to chemical plants","process":"fill","text":"Most methanol goes on to make formaldehyde, acetic acid and fuel additives. Biodiesel makers use it to split vegetable oil.","inputs":[]}],"facts":["A 1924 BASF patent application described making methanol at up to 220 atmospheres and 450 °C.","Astronomers have found a methanol cloud in space 0.463 terametres across.","In 2019 China used as much as 7 million tons of methanol as transportation fuel."],"where":[],"whereNote":null,"sources":[{"title":"Methanol","url":"https://en.wikipedia.org/wiki/Methanol"},{"title":"Methanol economy","url":"https://en.wikipedia.org/wiki/Methanol_economy"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mezcal","name":"Mezcal","kind":"product","category":"drink","title":"How mezcal is made","url":"https://assemblyline.org/make/mezcal","stations":6,"upstream":23,"downstream":0,"depth":6,"dek":"The smoky taste comes from roasting the agave hearts for about three days in an earthen pit full of hot rocks.","answer":"Mezcal is a spirit distilled from any type of agave. The plant takes seven to fifteen years to mature, then the heart is cut out and cooked for about three days, often in a pit oven with hot rocks. It is crushed, fermented in vats and distilled twice in clay or copper pots.","aka":["mescal","agave spirit"],"inputs":["agave","glass-bottle"],"uses":[],"grounds":["agave","silica-sand","limestone","rock-salt","water","trona","natural-gas","air","corn","crude-oil","sugarcane","sugar-beet"],"upstreamSlugs":["agave","glass-bottle","silica-sand","soda-ash","limestone","polyethylene","rock-salt","water","ammonia","carbon-dioxide","lime","trona","ethylene","natural-gas","air","corn","yeast","naphtha","molasses","crude-oil","hydrogen","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut out the agave heart","process":"harvest","text":"A mezcal agave takes between seven and fifteen years to mature. Workers cut off the leaves and roots to leave the piña, or heart, which can weigh about 40 kilograms.","inputs":["agave"]},{"name":"Roast in an earth pit","process":"cook","text":"The piñas are cooked for about three days, often in earthen mounds over pits of hot rocks. That underground roasting gives mezcal its intense smoky flavor.","inputs":[],"spec":"about 3 days"},{"name":"Crush the cooked hearts","process":"crush","text":"The softened piñas are crushed and mashed, traditionally by a stone wheel turned by a horse.","inputs":[]},{"name":"Ferment in open vats","process":"ferment","text":"The mash ferments in large vats or barrels, and the liquid is collected. Traditional rules for artisanal mezcal allow animal skins, stone, clay or wooden tanks.","inputs":[]},{"name":"Distill in clay or copper","process":"refine","text":"The liquid is distilled twice in clay or copper pots, which further shape the flavor. Mezcal can reach an alcohol content of 55 percent.","inputs":[]},{"name":"Bottle young or age it","process":"fill","text":"Unaged mezcal is called joven. Some is aged in barrels from one month to four years, and a little as long as 12 years.","inputs":["glass-bottle"]}],"facts":["Mezcal does not contain mescaline or any other psychedelic substance despite the similar name.","The distilling technology came with Filipino sailors and migrants during the Manila galleon trade between 1565 and 1815.","Some traditional mezcales de pechuga include fruit, meat or herbs in the second or third distillation."],"where":[],"whereNote":null,"sources":[{"title":"Mezcal","url":"https://en.wikipedia.org/wiki/Mezcal"},{"title":"Tequila","url":"https://en.wikipedia.org/wiki/Tequila"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mica","name":"Mica","kind":"raw","category":"ground","title":"How mica is mined","url":"https://assemblyline.org/make/mica","stations":3,"upstream":0,"downstream":3,"depth":0,"dek":"A mica crystal peels apart into thin, flexible plates like the pages of a book.","answer":"Mica is a group of silicate minerals whose crystals split into thin, bendy, transparent plates. Large crystals are mined from granite pegmatites and split into sheets. Scrap and flake mica is ground into powder that gives shimmer to cosmetics, and goes into paint, drywall and car parts.","aka":["muscovite","isinglass","mica sheet"],"inputs":[],"uses":["toaster","foundation-makeup","eyeshadow"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["toaster","foundation-makeup","eyeshadow"],"steps":[{"name":"Dig the pegmatite","process":"mine","text":"Large mica crystals sit in coarse granite called pegmatite. Miners dig out the rock and pull out the books of mica by hand or machine.","inputs":[]},{"name":"Split the books into sheets","process":"cut","text":"Mica has perfect cleavage because its layers are held together by weak ionic bonds. Workers peel a book into thin sheets that are chemically inert, flexible and good electrical insulators.","inputs":[]},{"name":"Grind scrap into flakes","process":"crush","text":"Scrap and small flake mica are ground to powder. Ground mica is sold for paint, drywall compound, cosmetics and car parts.","inputs":[]}],"facts":["The largest documented mica crystal weighed about 330 tonnes and was found at Lacey Mine in Ontario.","Mica gives cosmetics and some foods their shimmer or frost.","The mica group includes 37 different phyllosilicate minerals."],"where":[{"place":"Russia","share":"100,000 tonnes of scrap and flake"},{"place":"Finland","share":"68,000 tonnes"},{"place":"United States","share":"53,000 tonnes"},{"place":"South Korea","share":"50,000 tonnes"},{"place":"France","share":"20,000 tonnes"}],"whereNote":"2010 scrap and flake mica output; global total 350,000 tonnes, with no reliable data for China (Wikipedia).","sources":[{"title":"Mica","url":"https://en.wikipedia.org/wiki/Mica"},{"title":"Muscovite","url":"https://en.wikipedia.org/wiki/Muscovite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"microchip","name":"Microchip","kind":"product","category":"electronics","title":"How microchips are made","url":"https://assemblyline.org/make/microchip","stations":8,"upstream":46,"downstream":28,"depth":8,"dek":"The newest chips are drawn with light that air absorbs, made by blasting flying tin droplets with a laser.","answer":"A microchip is built on a polished silicon wafer, layer by layer, in a cleanroom. Each layer is coated with light-sensitive resist, exposed through a mask, etched and filled with dopants or copper. This cycle repeats many times. Finished dies are tested, sawed apart and wired into packages.","aka":["integrated circuit","IC","silicon chip","processor chip"],"inputs":["silicon-wafer","oxygen","photoresist","tin","copper","aluminum","gold"],"uses":["hearing-aid","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","rocket","smartwatch","wireless-earbuds","phone-charger","usb-cable","digital-camera","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush"],"grounds":["quartz","air","tin-ore","copper-ore","water","crude-oil","coal","gold-ore","sulfur","bauxite","limestone","zinc-ore","rock-salt","timber","natural-gas"],"upstreamSlugs":["silicon-wafer","oxygen","photoresist","tin","copper","aluminum","gold","polysilicon","quartz","argon","air","phenolic-resin","tin-ore","coke","copper-ore","water","sulfuric-acid","crude-oil","coal","petroleum-coke","alumina","gold-ore","lime","zinc","chlorine","silicon","hydrochloric-acid","trichlorosilane","hydrogen","nitrogen","phenol","formaldehyde","sulfur","bauxite","caustic-soda","limestone","zinc-ore","rock-salt","charcoal","timber","natural-gas","benzene","propylene","methanol","naphtha","toluene"],"downstreamSlugs":["hearing-aid","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","rocket","smartwatch","wireless-earbuds","phone-charger","usb-cable","digital-camera","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","car"],"steps":[{"name":"Grow an oxide skin","process":"heat-treat","text":"Wafers travel in sealed boxes and are heated in oxygen until a thin layer of glassy silicon dioxide forms on top. This layer insulates and protects the silicon below.","inputs":["silicon-wafer","oxygen"]},{"name":"Spread on light-sensitive resist","process":"coat","text":"A liquid made from resin, a light-sensitive chemical and solvent is spread across the whole wafer, then baked solid.","inputs":["photoresist"]},{"name":"Draw circuits with ultraviolet","process":"etch","text":"In the most advanced machines, a laser hits tin droplets about 25 micrometers wide, flying at roughly 70 meters per second, and the resulting plasma emits light at 13.5 nm. Glass and air absorb that light, so mirrors in a vacuum steer it onto the wafer.","inputs":["tin"],"spec":"13.5 nm light"},{"name":"Etch and implant","process":"etch","text":"A developer washes away the exposed resist. Plasma etching then cuts the pattern into the layer below, or ion implantation embeds dopant atoms in the open areas to change how well silicon conducts.","inputs":[]},{"name":"Lay down copper wiring","process":"deposit","text":"Thin films of insulator and copper are deposited on top, forming the wires that connect transistors.","inputs":["copper"]},{"name":"Repeat layer by layer","process":"etch","text":"A complex chip goes through the coat, expose, etch cycle many times. At advanced nodes the whole run takes up to 15 weeks, and 11 to 13 weeks is the industry average.","inputs":[],"spec":"11 to 15 weeks"},{"name":"Probe every die","process":"inspect","text":"Automatic test equipment touches each die on the wafer and checks that it works, so faulty chips are not built into expensive packages.","inputs":[]},{"name":"Saw and wire up","process":"cut","text":"The wafer is cut into individual dies. Each good die is connected to a package with fine aluminum or gold bond wires, or flipped over onto bumps, and tested again.","inputs":["aluminum","gold"]}],"facts":["Each tin droplet is hit twice by the laser: a weak pulse flattens it into a pancake of vapor, and a strong pulse turns it into glowing plasma.","Since 1994 the nanometer number in a process node name has had no standard relation to the real size of any feature on the chip.","Ambient urban air holds 35,000,000 particles of 0.5 micrometers and larger per cubic meter, which matches the ISO 9 cleanroom rating."],"where":[],"whereNote":null,"sources":[{"title":"Semiconductor device fabrication","url":"https://en.wikipedia.org/wiki/Semiconductor_device_fabrication"},{"title":"Extreme ultraviolet lithography","url":"https://en.wikipedia.org/wiki/Extreme_ultraviolet_lithography"},{"title":"Photolithography","url":"https://en.wikipedia.org/wiki/Photolithography"},{"title":"Cleanroom","url":"https://en.wikipedia.org/wiki/Cleanroom"},{"title":"Integrated circuit","url":"https://en.wikipedia.org/wiki/Integrated_circuit"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"microphone","name":"Microphone","kind":"product","category":"electronics","title":"How microphones are made","url":"https://assemblyline.org/make/microphone","stations":8,"upstream":62,"downstream":0,"depth":8,"dek":"A microphone is a loudspeaker in reverse, with moving air creating the current instead of current moving the air.","answer":"A dynamic model starts as a pressed aluminum or molded plastic case. Fine enameled copper wire is wound on a plastic bobbin and glued to a thin diaphragm, then the pair is lowered into a sintered neodymium magnet. A soldered cable, a foam spacer and a grille finish it. Condenser types swap the coil for two closely spaced metal plates.","aka":["mic","dynamic microphone","condenser microphone"],"inputs":["aluminum","plastic","copper-wire","adhesive","neodymium-magnet","polyester","solder"],"uses":[],"grounds":["crude-oil","coal","natural-gas","water","rare-earth-ore","bauxite","copper-ore","air","nickel-ore","zinc-ore","tin-ore","lead-ore","silver-ore","rock-salt","limestone","sulfur","corn","sugarcane","sugar-beet"],"upstreamSlugs":["aluminum","plastic","copper-wire","adhesive","neodymium-magnet","polyester","solder","crude-oil","coal","petroleum-coke","alumina","naphtha","natural-gas","ethylene","propylene","copper","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","rare-earth-ore","nickel","zinc","pet-plastic","tin","lead","silver","bauxite","caustic-soda","lime","hydrogen","copper-ore","oxygen","air","sulfuric-acid","ammonia","methanol","phenol","acetone","chlorine","nitric-acid","nickel-ore","zinc-ore","p-xylene","ethylene-glycol","tin-ore","coke","lead-ore","silver-ore","rock-salt","limestone","sulfur","benzene","carbon-dioxide","toluene","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Form the case","process":"press","inputs":["aluminum","plastic"],"text":"A hydraulic punch forces thin aluminum sheet into a die, and the excess is trimmed off. Plastic cases are injection molded instead. Any switch is then fixed in place with small screws or rivets."},{"name":"Wind the coil","process":"assemble","inputs":["copper-wire","adhesive"],"text":"Very fine enameled copper wire is wound many turns around a small plastic bobbin and glued so it stays put."},{"name":"Sinter the magnet","process":"press","inputs":["neodymium-magnet"],"text":"Neodymium iron boron powder is squeezed and heated in a high-pressure die until it fuses solid. It can also be bonded with plastic binders."},{"name":"Glue on the diaphragm","process":"assemble","inputs":["polyester","adhesive"],"text":"A pre-cut plastic diaphragm sits in a holding fixture while the bobbin is glued exactly in its center. The joint is left alone to cure.","spec":"about 24 hours"},{"name":"Lower into the magnet","process":"assemble","inputs":[],"text":"The cured diaphragm and coil are set down into the magnet assembly and glued. Sound will now push the coil along its axis and induce a current."},{"name":"Measure the response","process":"inspect","inputs":[],"text":"The coil assembly goes on a test station that plays white noise, which holds every audible frequency at once. Its response has to land within specification."},{"name":"Solder in the cable","process":"assemble","inputs":["solder","copper-wire"],"text":"A coaxial cable is cut and stripped, and one end gets a soldered audio connector. The free end threads up through the bottom of the case and is soldered to the switch and coil."},{"name":"Close with the grille","process":"assemble","inputs":[],"text":"A foam rubber spacer wraps the coil assembly, which is lowered into the case and locked in place by a grille and cap."}],"facts":["RCA's ribbon microphone of 1931 weighed about 8 pounds and could be damaged just by blowing into it.","Alexander Graham Bell's first microphone of 1876, a telephone transmitter, relied on liquid and was far from practical."],"where":[],"whereNote":null,"sources":[{"title":"Microphone (How Products Are Made)","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/microphone"},{"title":"Microphone","url":"https://en.wikipedia.org/wiki/Microphone"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"microwave-oven","name":"Microwave oven","kind":"product","category":"machines","title":"How microwave ovens are made","url":"https://assemblyline.org/make/microwave-oven","stations":10,"upstream":87,"downstream":0,"depth":10,"dek":"The part that cooks your food is a vacuum tube first developed to power wartime radar.","answer":"Inside each oven sits a vacuum tube, the magnetron, making waves near 2.45 gigahertz. Presses stamp the steel frame, a charged paint tank coats it, and workers build the tube from its anode, cathode, magnet and cooling fins. Chassis, door, transformer and stirrer fan bolt together, a roll-formed case slips over them, and scanners hunt for leakage around the door before shipping.","aka":["microwave","microwave cooker"],"inputs":["sheet-steel","paint","copper","glass","transformer","electric-motor","printed-circuit-board"],"uses":[],"grounds":["water","copper-ore","air","silica-sand","limestone","zinc-ore","titanium-ore","iron-ore","sulfur","rock-salt","trona","dolomite","manganese-ore","natural-gas","coal","crude-oil","corn","tin-ore","lead-ore","silver-ore","quartz","timber","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["sheet-steel","paint","copper","glass","transformer","electric-motor","printed-circuit-board","steel","zinc","water","titanium-dioxide","pigment","acrylic","tin-can","copper-ore","oxygen","air","sulfuric-acid","silica-sand","soda-ash","limestone","copper-wire","epoxy","ball-bearing","fiberglass","photoresist","solder","pig-iron","magnesium","steel-scrap","lime","manganese","argon","zinc-ore","titanium-ore","chlorine","coke","iron-ore","carbon-black","sulfur","propylene","ammonia","methanol","tinplate","lacquer","ink","rock-salt","carbon-dioxide","trona","phenol","acetone","caustic-soda","steel-wire","phenolic-resin","tin","lead","silver","dolomite","silicon","propane","manganese-ore","natural-gas","coal","crude-oil","naphtha","ethanol","vegetable-oil","corn","yeast","benzene","formaldehyde","tin-ore","lead-ore","silver-ore","quartz","charcoal","timber","hydrogen","sugarcane","ethylene","soybeans","rapeseed","hexane","clay","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Press the frame","process":"stamp","text":"Automatic metal-forming presses shape the cavity and door parts from steel, often galvanized or stainless. An alkaline wash takes off dirt and oil, and plain water rinses away the wash.","inputs":["sheet-steel"],"spec":"12 to 15 parts per minute"},{"name":"Dip in charged paint","process":"coat","text":"A zinc phosphate treatment prepares each part for electro-deposition. Parts sink into a live paint tank and pick up a coat about 1.5 mils thick, which is then baked hard.","inputs":["paint"],"spec":"200 volts for 2.5 minutes, then 300 °F for 20 minutes"},{"name":"Fix the door screen","process":"assemble","text":"A perforated metal plate goes over the window opening in the painted door. Its holes are far smaller than the waves, so it turns them back while light still gets through.","inputs":["sheet-steel"]},{"name":"Build the magnetron","process":"assemble","text":"A filament goes on the cathode, and the cathode goes inside an anode cylinder, almost always copper. Cooling fins are welded on and a strong magnet wraps around. An antenna in a glass tube is fitted on top, and air is pumped out of the tube to leave a vacuum.","inputs":["copper","glass"]},{"name":"Mount cavity on chassis","process":"assemble","text":"Working on a pallet, assemblers screw the cavity to the main chassis, hang the door on its hinges and bolt the magnetron to the side. A waveguide carries the waves into the cavity.","inputs":[]},{"name":"Wire the high voltage","process":"assemble","text":"The circuit that powers the tube needs a big transformer, a rectifier and a capacitor filled with oil. All three sit right on the chassis near the magnetron.","inputs":["transformer"]},{"name":"Fit stirrer or turntable","process":"assemble","text":"A fan on top of the cavity scatters the waves, driven by a pulley from the blower motor or by its own motor. A shield keeps out grease that could cause arcing in the waveguide. Many models rotate the food on a ceramic or glass plate as well.","inputs":["electric-motor","glass"]},{"name":"Add switches and controls","process":"assemble","text":"Relays, timers and door switches are mounted, and the front panel goes on with its circuit board behind it. Regulations demand two independent interlocks that kill the waves the moment the door opens.","inputs":["printed-circuit-board"]},{"name":"Roll the outer case","process":"roll","text":"A roll former wraps metal into a one-piece case. It slides over the built-up unit and is bolted to the chassis, and the power cord and knobs go on.","inputs":["sheet-steel"]},{"name":"Run and scan","process":"inspect","text":"One older account says makers ran each unit continuously for 50 to 100 hours, though modern lines generally use much shorter power tests. A computer-controlled scanner checks for leaks around the door, window and back, against a federal limit of 5 milliwatts per square centimeter about 2 inches away.","inputs":[],"spec":"5 milliwatts per square centimeter leak limit"}],"facts":["Over one billion magnetrons are in use in microwave ovens.","The first Radarange was 1.8 meters tall and weighed 340 kilograms.","Early commercial microwave ovens cost about $3,000, a price that kept them in hospitals and hotels."],"where":[],"whereNote":null,"sources":[{"title":"Microwave Oven, How Products Are Made","url":"https://encyclopedia.com/manufacturing/news-wires-white-papers-and-books/microwave-oven"},{"title":"Microwave oven","url":"https://en.wikipedia.org/wiki/Microwave_oven"},{"title":"Cavity magnetron","url":"https://en.wikipedia.org/wiki/Magnetron"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"popcorn","name":"Microwave popcorn","kind":"product","category":"food","title":"How microwave popcorn is made","url":"https://assemblyline.org/make/popcorn","stations":8,"upstream":64,"downstream":0,"depth":10,"dek":"One patented popcorn line fills 50 to 100 bags a minute, shooting in melted fat as a thin vertical jet.","answer":"Dried popcorn is shelled, screened and polished at a processing plant, then sent to a bag line. Each bag is folded, filled with kernels at one station and a melted fat and salt slurry at the next, then sealed across the top. A second fold, a moisture-barrier overwrap and a carton finish the package. Microwaves do the popping at home.","aka":["microwave popcorn","popped corn"],"inputs":["corn","paper","palm-oil","table-salt","adhesive","plastic-wrap","cardboard-box"],"uses":[],"grounds":["corn","water","kaolin","limestone","oil-palm-fruit","rock-salt","seawater","timber","crude-oil","air","natural-gas","sulfur","iron-ore","soybeans","rapeseed","clay","titanium-ore","sugarcane","coal","sugar-beet"],"upstreamSlugs":["corn","paper","palm-oil","table-salt","adhesive","plastic-wrap","cardboard-box","wood-pulp","water","kaolin","limestone","oil-palm-fruit","rock-salt","seawater","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","pvc","cardboard","ink","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","hydrogen","pigment","plasticizer","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","ethanol","air","naphtha","natural-gas","sulfur","benzene","iron-ore","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","coke","sugarcane","yeast","toluene","coal","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cure on the stalk","process":"harvest","text":"Growers leave the crop standing as long as they dare, weighing drier kernels against fall damp and toppling stalks. Machines now do almost all the picking.","inputs":["corn"]},{"name":"Dry to popping moisture","process":"dry","text":"Picked ears dry in ventilated cribs or with heated air until they hold 13.5 to 14 percent water. A cereal chemistry study found that the best level shifts a little with kernel size, and that missing it costs expansion.","inputs":[],"spec":"13.5 to 14% moisture"},{"name":"Shell, screen and polish","process":"separate","text":"At the plant the kernels come off the cob and ride over screens and separators that pull out broken pieces and debris. Polishing machines then rub away any clinging chaff.","inputs":[]},{"name":"Fold the empty bag","process":"assemble","text":"Tubular bag stock, usually paper plies around a microwave susceptor film, is cut to length and sealed at the bottom. The lower third folds up, so the charge will sit in the middle of the bag.","inputs":["paper"]},{"name":"Drop in the kernels","process":"fill","text":"A chain with clips carries each open bag upright to a filling station, where a device such as a dispensing wheel measures out the kernels.","inputs":[]},{"name":"Jet in the slurry","process":"fill","text":"At the next station melted fat carrying very fine salt shoots down as a confined stream called a pencil jet. One patent's example gives about 35 grams in half a second. Coarse salt can plug that nozzle, so that patent drops it in at a third station.","inputs":["palm-oil","table-salt"]},{"name":"Seal the top","process":"assemble","text":"Jaws close on the open end with heat or pressure and lock the charge inside. Heat or an adhesive holds the seal.","inputs":["adhesive"]},{"name":"Fold and overwrap","process":"package","text":"A second fold gives the familiar three-folded packet. A moisture-barrier overwrap goes around it, and the wrapped bags are counted into cartons.","inputs":["plastic-wrap","cardboard-box"]}],"facts":["Charles Cretors introduced the first patented steam-driven popcorn machine at the Columbian Exposition in 1893.","Fossil evidence from Peru suggests corn grew there by 4,700 BCE.","A popped kernel is known in the industry as a flake, and butterfly flakes are more tender than mushroom ones."],"where":[],"whereNote":null,"sources":[{"title":"From the Field to the Table, USDA National Agricultural Library","url":"https://www.nal.usda.gov/exhibits/speccoll/exhibits/show/popcorn/from-the-field-to-the-table"},{"title":"US5897894A, Microwave popcorn with coarse salt crystals","url":"https://patents.google.com/patent/US5897894/en"},{"title":"Optimum Popping Moisture Content for Popcorn Kernels of Different Sizes, Cereal Chemistry","url":"https://www.cerealsgrains.org/publications/cc/backissues/1994/Documents/CC1994a117.html"},{"title":"Popcorn","url":"https://en.wikipedia.org/wiki/Popcorn"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mirror","name":"Mirror","kind":"product","category":"minerals","title":"How mirrors are made","url":"https://assemblyline.org/make/mirror","stations":5,"upstream":78,"downstream":0,"depth":10,"dek":"A bathroom mirror is plain window glass with a film of silver on the back, hidden under a coat of paint.","answer":"A household mirror is a plate of soda-lime glass coated on its back with a thin film of metal, usually silver, and then sealed under paint. The silver is deposited by a chemical reduction of silver nitrate, a method Justus von Liebig invented in 1835. Telescope mirrors instead get a vacuum-deposited aluminum coating.","aka":["looking glass","glass mirror","silvered glass"],"inputs":["window-glass","silver","aluminum","paint"],"uses":[],"grounds":["silica-sand","limestone","dolomite","silver-ore","lead-ore","zinc-ore","copper-ore","crude-oil","coal","water","rock-salt","trona","tin-ore","air","natural-gas","sulfur","bauxite","titanium-ore","iron-ore","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet","manganese-ore","quartz","timber"],"upstreamSlugs":["window-glass","silver","aluminum","paint","silica-sand","soda-ash","limestone","dolomite","tin","nitrogen","hydrogen","silver-ore","lead-ore","zinc-ore","copper-ore","zinc","sulfuric-acid","lime","crude-oil","coal","petroleum-coke","alumina","water","titanium-dioxide","pigment","acrylic","tin-can","rock-salt","ammonia","carbon-dioxide","trona","tin-ore","coke","air","natural-gas","sulfur","bauxite","caustic-soda","titanium-ore","chlorine","oxygen","iron-ore","carbon-black","propylene","methanol","tinplate","lacquer","ink","corn","yeast","naphtha","steel","ethanol","vegetable-oil","phenolic-resin","molasses","pig-iron","magnesium","steel-scrap","manganese","argon","sugarcane","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","sugar-beet","silicon","propane","manganese-ore","benzene","quartz","charcoal","timber","toluene"],"downstreamSlugs":[],"steps":[{"name":"Cut the glass plate","process":"cut","text":"The base is a plate of transparent glass, usually soda-lime float glass. Lead glass is sometimes used for decorative effect, and plastic is used where weight or breakage matters.","inputs":["window-glass"]},{"name":"Silver the back","process":"coat","text":"In the wet process, a solution of silver nitrate is chemically reduced onto the glass, leaving a thin layer of metallic silver. This replaced the old tin-mercury amalgam and made mirrors affordable.","inputs":["silver"]},{"name":"Or vacuum-coat aluminum","process":"deposit","text":"Mirrors for optical instruments are usually made in a vacuum chamber, where aluminum is sputtered or evaporated onto the glass. Many of them carry the metal on the front face so light does not have to cross the glass twice.","inputs":["aluminum"]},{"name":"Paint over the metal","process":"coat","text":"A layer of paint goes over the metal to shield it from abrasion and corrosion. Without it the thin film would scratch or tarnish within months.","inputs":["paint"]},{"name":"Bond a safety film","process":"laminate","text":"A flexible transparent plastic film is sometimes bonded to the front or back, so that if the glass breaks, the pieces stay in place instead of falling.","inputs":[]}],"facts":["Obsidian mirrors found at Çatalhöyük in Anatolia date to around 6000 BCE.","In the late seventeenth century, the Countess de Fiesque reportedly traded an entire wheat farm for a Venetian mirror and considered it a bargain.","Aluminum reflects 85 to 90% of visible light, and it resists tarnishing better than silver does."],"where":[],"whereNote":null,"sources":[{"title":"Mirror","url":"https://en.wikipedia.org/wiki/Mirror"},{"title":"Silvered glass","url":"https://en.wikipedia.org/wiki/Silvered_glass"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"modeling-clay","name":"Modeling compound","kind":"product","category":"play","title":"How modeling compound is made","url":"https://assemblyline.org/make/modeling-clay","stations":7,"upstream":33,"downstream":0,"depth":9,"dek":"Play-Doh began as a wallpaper cleaner, and it is mostly flour, salt and water.","answer":"Flour-based modeling compound starts as a dry blend. One patent premixes dyes with a little acid, tumbles that with salt, flour and talc in a conical mixer, then pours in oil. Adding water and heat swells the flour's starch into a dough. The dough is kneaded smooth and scented, then sealed away from the air so it stays soft.","aka":["play dough","playdough","Play-Doh","modelling clay"],"inputs":["flour","table-salt","vegetable-oil","water"],"uses":[],"grounds":["water","wheat","rock-salt","seawater","soybeans","rapeseed","clay","air","crude-oil","corn","natural-gas","sugarcane","sugar-beet","limestone"],"upstreamSlugs":["flour","table-salt","vegetable-oil","water","wheat","vitamin-c","rock-salt","seawater","soybeans","rapeseed","hexane","clay","corn-starch","hydrogen","air","sugar","plastic-bottle","crude-oil","corn","natural-gas","sugarcane","sugar-beet","lime","pet-plastic","limestone","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","yeast","molasses"],"downstreamSlugs":[],"steps":[{"name":"Premix dye and acid","process":"mix","text":"One patent stirs its dyes into tartaric acid first, because that premix spreads the color evenly through the much bigger batch to come.","inputs":[]},{"name":"Blend the dry powders","process":"mix","text":"Salt goes into a conical auger mixer, followed slowly by the premix, flour and sterilized talc. Mixing runs about five minutes. Flour is the binder that gives the compound its body.","inputs":["flour","table-salt"],"spec":"about 5 minutes"},{"name":"Pour in the oil","process":"mix","text":"Oil trickles in as the mixer turns, for about five more minutes, until evenly spread. It coats the flour particles and later reduces stickiness.","inputs":["vegetable-oil"]},{"name":"Work in hot water","process":"cook","text":"Water and heat gelatinize the flour, swelling the starch granules until the mixture thickens into a dough. Done right, this avoids a sticky paste that would be messy to handle.","inputs":["water"]},{"name":"Knead it smooth","process":"knead","text":"The batch is worked until it is uniform, soft and cohesive. A lubricant in the recipe gives it a smooth feel.","inputs":[]},{"name":"Add the scent","process":"mix","text":"Fragrance is mixed in. One brand's trademarked scent mixes a sweet, vanilla-like note with the smell of a salted, wheat-based dough.","inputs":[]},{"name":"Seal it from the air","process":"package","text":"Finished compound is pressed into tubs and sealed so the water stays in. Random samples from the packing line get a pH check.","inputs":[]}],"facts":["Play-Doh began in the 1930s as a putty to clean coal soot from wallpaper.","Declining coal heat and the arrival of washable vinyl wallpaper shrank the market for the cleaner, and the maker turned to schoolchildren.","The Play-Doh Fun Factory press that squeezes the dough into shapes was invented in 1960."],"where":[],"whereNote":null,"sources":[{"title":"US4386964A, Modelling compounds","url":"https://patents.google.com/patent/US4386964/en"},{"title":"Modeling compound patent US6713624","url":"https://patents.google.com/patent/US6713624"},{"title":"Play-Doh","url":"https://en.wikipedia.org/wiki/Play-Doh"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"molasses","name":"Molasses","kind":"material","category":"food","title":"How molasses is made","url":"https://assemblyline.org/make/molasses","stations":5,"upstream":2,"downstream":351,"depth":1,"dek":"Molasses is what is left after cane juice has been boiled and stripped of sugar crystals three times.","answer":"Molasses is the thick syrup left behind when sugar is crystallized from cane or beet juice. Cane is crushed and the juice boiled, and sugar crystals are drawn off. After the first boiling comes the lightest syrup. A third boiling leaves dark, bitter blackstrap, from which most of the sucrose has been removed.","aka":["blackstrap molasses","black treacle","cane syrup"],"inputs":["sugarcane","sugar-beet"],"uses":["brown-sugar","yeast","rum","caramel-color","licorice","root-beer"],"grounds":["sugarcane","sugar-beet"],"upstreamSlugs":["sugarcane","sugar-beet"],"downstreamSlugs":["brown-sugar","yeast","rum","caramel-color","licorice","root-beer","insulin","ethanol","vinegar","bread","croissant","donut","pretzel","beer","wine","champagne","whiskey","vodka","gin","tequila","sake","hard-cider","frozen-pizza","bagel","baguette","crackers","carbon-dioxide","bourbon","scotch","mead","port-wine","prosecco","light-beer","non-alcoholic-beer","cola","soda","deodorant","perfume","vaccine","gasoline","ink","vanilla-extract","lacquer","super-glue","insect-repellent","air-freshener","hairspray","mouthwash","mayonnaise","ketchup","mustard","hot-sauce","salsa","pickles","fish-sticks","aspirin","soda-ash","fertilizer","baking-soda","decaf-coffee","sparkling-water","refrigerant","popping-candy","energy-drink","tonic-water","caffeine","melamine-resin","ethylene-glycol","shampoo","dish-soap","foundation-makeup","car","car-engine","motorcycle","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","ice-cream","white-chocolate","caramel","guitar","electric-guitar","trumpet","chopsticks","door","chess-set","saxophone","ukulele","felt-hat","baseball-bat","detergent","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","instant-noodles","stained-glass","vanadium","cake-mix","fire-extinguisher","refrigerator","air-conditioner","asthma-inhaler","pet-plastic","spandex","locomotive","vacuum-cleaner","electric-kettle","cotton-candy","pillow","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","electric-car","soap","toothpaste","nitrile-glove","washing-machine","paperclip","corn-flakes","popcorn","crayon","fireworks","candle","zip-bag","blender","dishwasher","cotton-swab","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","printed-circuit-board","wind-turbine","surfboard","fishing-rod","kite","roof-shingle","canoe","sailboat","lithium-ion-cell","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather","thermometer","lcd-screen","oled-screen","camera-sensor","solar-panel","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","neon-sign","smartwatch","e-reader","mirror","skyscraper","double-glazed-window","nail-polish","penicillin","kombucha","cognac","mezcal","smartphone","polyester","plastic-bottle","3d-printer-filament","drum-kit","bottled-water","leggings","swimsuit","pencil","scissors","airplane","container-ship","shipping-container","bicycle","wooden-chair","water-bottle","ceiling-fan","tennis-racket","golf-club","billiard-ball","dartboard","dice","action-figure","fashion-doll","toy-car","coil-spring","hammer","gas-cylinder","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","hearing-aid","pacemaker","led-bulb","ev-battery","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","airbag","rocket","elevator","treadmill","pinball-machine","phone-charger","digital-camera","graphics-card","electric-toothbrush","kitchen-knife","fork","fountain-pen","thermos","pressure-cooker","jet-engine","football","winter-gloves","handbag","wallet","hiking-boots","high-heels","leather-shoe","sauerkraut","jam","hazelnut-spread","tire","sofa","office-chair","garden-hose","volleyball","kitchen-sponge","wet-wipes","seat-belt","hoodie","raincoat","backpack","suitcase","shoelace","curtain","microphone","sneaker","mattress","zipper","button","thread","teddy-bear","sunscreen","bleach","vitamin-c","hair-dye","padlock","down-jacket","jeans","dress-shirt","suit","baseball-cap","bike-helmet","yo-yo","tampon","silk-tie","blanket","socks","sweater","towel","flour","tortilla","sandwich-cookie","chicken-nuggets","sourdough","modeling-clay"],"steps":[{"name":"Crush the cane for juice","process":"press","text":"Cane is stripped of its leaves, then cut, crushed or mashed until the juice runs out. Sugar beet juice gives a similar syrup.","inputs":["sugarcane","sugar-beet"]},{"name":"Boil the juice down","process":"cook","text":"Boiling the juice to a concentrate makes sugar crystallize. What is left after this first boiling is the first syrup.","inputs":[]},{"name":"Spin out the crystals","process":"separate","text":"Crystals of raw sugar are drawn out of the thick liquid. What remains is molasses.","inputs":[]},{"name":"Boil it twice more","process":"cook","text":"Boiling the syrup again and again pulls out more sucrose. A third boiling yields dark, viscous blackstrap molasses.","inputs":[],"spec":"third boiling gives blackstrap"},{"name":"Ship it onward","process":"package","text":"Blackstrap is drummed and tanked for rum distillers, feed makers and yeast producers. The syrup is sold in smaller jars for baking.","inputs":[]}],"facts":["Blackstrap molasses is used for yeast production and cattle feed, and to make ethanol.","Molasses was a common sweetener across the Americas before the 20th century.","George Washington kept a recipe for molasses beer in a notebook."],"where":[],"whereNote":null,"sources":[{"title":"Molasses","url":"https://en.wikipedia.org/wiki/Molasses"},{"title":"Caramel color","url":"https://en.wikipedia.org/wiki/Caramel_color"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"motor-oil","name":"Motor oil","kind":"product","category":"chemicals","title":"How motor oil is made","url":"https://assemblyline.org/make/motor-oil","stations":5,"upstream":4,"downstream":0,"depth":2,"dek":"A bottle of motor oil is refined heavy crude plus a kit of additives that can top a fifth of the contents.","answer":"Motor oil begins as the heavy fraction distilled from crude oil, which refiners clean of aromatics and waxes and treat with hydrogen to form base oil. Blenders then add detergents, dispersants, anti-wear compounds and viscosity improvers. The bulk of the oil is hydrocarbons with 18 to 34 carbon atoms per molecule.","aka":["engine oil","engine lubricant","lube oil"],"inputs":["crude-oil","hydrogen"],"uses":[],"grounds":["crude-oil","natural-gas","water"],"upstreamSlugs":["crude-oil","hydrogen","natural-gas","water"],"downstreamSlugs":[],"steps":[{"name":"Distill the heavy fraction","process":"refine","text":"Heating crude oil lets the light parts be taken off for fuels. What stays behind becomes lubricant base stock.","inputs":["crude-oil"]},{"name":"Strip out aromatics","process":"separate","text":"The heavy cut is mixed with a solvent that preferentially dissolves aromatic compounds, such as phenol or furfural. The aromatics are drawn away and the solvent is recovered.","inputs":[]},{"name":"Remove the waxes","process":"refine","text":"Long-chain waxes precipitate at relatively high temperature, so they would clog oil in the cold. They are crystallized out or rearranged into branched molecules.","inputs":[]},{"name":"Treat with hydrogen","process":"react","text":"Hydrogenation removes leftover aromatics and nitrogen and sulfur compounds. The more of this treatment, the higher the base oil group.","inputs":["hydrogen"]},{"name":"Blend with additives","process":"mix","text":"Base oil is blended with detergents, dispersants, antiwear additives, corrosion inhibitors and viscosity index improvers. Some blends add synthetic polyalphaolefins.","inputs":[]}],"facts":["The top piston ring can expose oil to 160 °C in a gasoline engine and over 315 °C in a diesel engine.","Certain types of motor oil contain more than twenty percent additives.","John Ellis got into lubricating oil in 1866 while studying whether crude oil could heal people."],"where":[],"whereNote":null,"sources":[{"title":"Motor oil","url":"https://en.wikipedia.org/wiki/Motor_oil"},{"title":"Base oil","url":"https://en.wikipedia.org/wiki/Base_oil"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"motorcycle","name":"Motorcycle","kind":"product","category":"machines","title":"How motorcycles are made","url":"https://assemblyline.org/make/motorcycle","stations":8,"upstream":101,"downstream":0,"depth":10,"dek":"A small 1958 Honda, the Super Cub, is the biggest-selling vehicle of all time.","answer":"A motorcycle is a steel or aluminum frame with an engine bolted in, telescopic forks up front and a swingarm at the back. Frames are welded and painted. Engines are cast and machined, then fitted with a transmission. Wheels, brakes, wiring and bodywork go on, and the bike is fueled and tested.","aka":["motorbike","bike"],"inputs":["steel","aluminum","paint","car-engine","tire","ball-bearing","copper-wire","printed-circuit-board","gasoline"],"uses":[],"grounds":["crude-oil","coal","water","silica-sand","natural-latex","sulfur","iron-ore","limestone","air","dolomite","manganese-ore","natural-gas","bauxite","titanium-ore","copper-ore","corn","sugarcane","quartz","timber","rock-salt","zinc-ore","lead-ore","tin-ore","trona","silver-ore","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["steel","aluminum","paint","car-engine","tire","ball-bearing","copper-wire","printed-circuit-board","gasoline","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","crude-oil","coal","petroleum-coke","alumina","water","titanium-dioxide","pigment","acrylic","tin-can","silica-sand","synthetic-rubber","natural-latex","carbon-black","sulfur","steel-wire","brass","nylon","polyester","sheet-steel","copper","fiberglass","epoxy","photoresist","solder","naphtha","hydrogen","ethanol","iron-ore","coke","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","bauxite","caustic-soda","titanium-ore","chlorine","propylene","ammonia","methanol","tinplate","lacquer","ink","benzene","ethylene","styrene","zinc","lead","tin","nitric-acid","pet-plastic","copper-ore","soda-ash","phenol","acetone","phenolic-resin","silver","corn","sugarcane","yeast","quartz","charcoal","timber","rock-salt","vegetable-oil","toluene","zinc-ore","lead-ore","tin-ore","p-xylene","ethylene-glycol","carbon-dioxide","trona","formaldehyde","silver-ore","molasses","soybeans","rapeseed","hexane","clay","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Weld the frame","process":"weld","text":"Steel or aluminum tubes and pressings are welded into the frame, the skeleton that carries the engine, wheels and rider. It includes the steering head for the front forks.","inputs":["steel","aluminum"]},{"name":"Cast and machine the engine","process":"cast","text":"Aluminum is poured into molds for the crankcase and cylinder head. A typical bike has one to four cylinders, and a few have more.","inputs":["aluminum"]},{"name":"Build the gearbox","process":"assemble","text":"Gears and shafts are fitted in the crankcase to make a manual transmission, commonly five- or six-speed. A chain, belt or driveshaft links the output to the rear wheel.","inputs":["steel"]},{"name":"Paint the tank and frame","process":"coat","text":"Fuel tank, fenders and frame are primed and sprayed, often with several layers of color and clear coat.","inputs":["paint"]},{"name":"Drop the engine in","process":"assemble","text":"The engine is lowered into the frame and bolted at several mounting points. Throttle, clutch and exhaust follow.","inputs":["car-engine"]},{"name":"Fit forks, swingarm and wheels","process":"assemble","text":"Telescopic forks hold the front wheel, and a swingarm with a shock absorber carries the rear one. Wheels arrive with tires already fitted.","inputs":["tire","ball-bearing"]},{"name":"Mount brakes and wire it","process":"assemble","text":"Disc brakes are bolted on, and a wiring loom is run for lights, ignition and charging.","inputs":["copper-wire","printed-circuit-board"]},{"name":"Fuel up and run it","process":"inspect","text":"Each bike is filled with oil and fuel, started, and run on rollers before it leaves the line.","inputs":["gasoline"]}],"facts":["The top four motorcycle producers by volume are Honda, Yamaha, Kawasaki and Suzuki.","The 1958 Honda Super Cub became the biggest-selling vehicle of all time, with its 60 millionth unit built in April 2008."],"where":[],"whereNote":null,"sources":[{"title":"Motorcycle","url":"https://en.wikipedia.org/wiki/Motorcycle"},{"title":"Bicycle frame","url":"https://en.wikipedia.org/wiki/Bicycle_frame"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mouthwash","name":"Mouthwash","kind":"product","category":"body-health","title":"How mouthwash is made","url":"https://assemblyline.org/make/mouthwash","stations":8,"upstream":60,"downstream":0,"depth":10,"dek":"A mouthwash batch can run 3,000 gallons, and a high-speed line then bottles over 20,000 an hour.","answer":"Compounders mix mouthwash in stainless steel tanks holding thousands of gallons. Deionized water and alcohol arrive by pipe, while flavors, antibacterial agents and dye are added by the operators, sometimes with a heating and cooling cycle. Once the lab approves a sample, the batch moves to a holding tank, and piston fillers load bottles at high speed.","aka":["mouth rinse","oral rinse","mouth wash"],"inputs":["water","ethanol","plastic-bottle","cardboard-box"],"uses":[],"grounds":["water","corn","sugarcane","natural-gas","sugar-beet","crude-oil","timber","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","limestone","rock-salt","coal"],"upstreamSlugs":["water","ethanol","plastic-bottle","cardboard-box","corn","sugarcane","yeast","ethylene","pet-plastic","cardboard","ink","adhesive","molasses","naphtha","natural-gas","p-xylene","ethylene-glycol","wood-pulp","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","sugar-beet","crude-oil","hydrogen","oxygen","carbon-dioxide","timber","caustic-soda","lime","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","propylene","ammonia","methanol","acetone","nitric-acid","limestone","rock-salt","benzene","coal","toluene"],"downstreamSlugs":[],"steps":[{"name":"Deionize the water","process":"refine","text":"Water makes up over half of most formulas. It is treated first to strip the particles and ions that could change the flavor.","inputs":["water"]},{"name":"Charge the main tank","process":"mix","text":"Forklifts bring raw materials to the compounding area, where operators add them to a stainless tank holding 2,000 to 3,000 gallons. Alcohol and water, used in bulk, are pumped in at the push of a button.","inputs":["ethanol"],"spec":"2,000 to 3,000 gallon batch"},{"name":"Carry in the flavor","process":"mix","text":"Flavor oils resist water. One patent mixes citrus flavor with ethanol first, then adds that blend to water already holding an emulsifier, along with a humectant and dyes. Agents such as thymol kill bacteria.","inputs":[]},{"name":"Heat, cool and stir","process":"mix","text":"Some formulas are heated and cooled so the materials combine quickly. Computers hold mixing speed and temperature, and a batch takes one to three hours.","inputs":[]},{"name":"Send a sample to QC","process":"inspect","text":"Lab staff examine appearance and flavor, and may run pH and viscosity. A batch out of range can be corrected, for example with more dye.","inputs":[]},{"name":"Fill on the carousel","process":"fill","text":"Approved liquid is pumped to a holding tank connected to the line. A hopper stands empty bottles upright on a conveyor, and piston heads on a carousel dose each one as it travels around.","inputs":["plastic-bottle"]},{"name":"Cap and label","process":"assemble","text":"A second hopper lines up caps, which are twisted or pushed on. Labels feed from spools and are stuck on with adhesive or heat pressed.","inputs":[]},{"name":"Box and palletize","process":"package","text":"Bottles are gathered in groups of 12 or 24, dropped into boxes and stacked on pallets. Fast lines top 20,000 bottles an hour.","inputs":["cardboard-box"]}],"facts":["In the late 1960s, Harald Loe of the Royal Dental College in Aarhus showed that chlorhexidine can stop dental plaque from forming.","Some mouthwashes contain up to 27 percent alcohol by volume as a carrier for flavor."],"where":[],"whereNote":null,"sources":[{"title":"Mouthwash, How Products Are Made (Gale), Encyclopedia.com","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/mouthwash"},{"title":"US4420471A, Citrus flavored mouthwash formulation method","url":"https://patents.google.com/patent/US4420471/en"},{"title":"Mouthwash","url":"https://en.wikipedia.org/wiki/Mouthwash"},{"title":"Chlorhexidine","url":"https://en.wikipedia.org/wiki/Chlorhexidine"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mozzarella","name":"Mozzarella","kind":"product","category":"food","title":"How mozzarella is made","url":"https://assemblyline.org/make/mozzarella","stations":7,"upstream":5,"downstream":1,"depth":2,"dek":"Mozzarella is hot curd kneaded and pulled like taffy until it turns stringy.","answer":"Milk is curdled, the curd is cut and drained, and then it rests until it is acidic enough to stretch. Workers or machines knead the curd in very hot water until it turns smooth and elastic, pull off portions and shape them into balls. The balls are chilled and held in brine or whey.","aka":["fior di latte","pizza cheese","pasta filata cheese"],"inputs":["pasteurized-milk","table-salt"],"uses":["frozen-pizza"],"grounds":["raw-milk","rock-salt","seawater"],"upstreamSlugs":["pasteurized-milk","table-salt","raw-milk","rock-salt","seawater"],"downstreamSlugs":["frozen-pizza"],"steps":[{"name":"Curdle the milk","process":"ferment","text":"Milk is warmed, soured with starter bacteria and set with rennet. It rests until it has gelled into a single soft block.","inputs":["pasteurized-milk"]},{"name":"Cut the curd small","process":"cut","text":"Wires slice the gel into small pieces, which lets whey drain out of each one. Smaller pieces mean a drier cheese.","inputs":[],"spec":"1 to 1.5 cm pieces"},{"name":"Stir and drain","process":"cook","text":"Stirring and gentle heat shrink the curds and push out whey. Whey drains away and the curds are collected into a solid mass.","inputs":[]},{"name":"Rest until stretchy","process":"ferment","text":"The curd mass sits while acid keeps building. Once the pH reaches the right window, the proteins will pull into long strands instead of crumbling.","inputs":[],"spec":"pH 5.2 to 5.5"},{"name":"Knead in hot water","process":"knead","text":"Curd is steeped in a bath of hot whey or water and then worked until it is smooth, shiny and stringy. Hot water pulls calcium out of the protein network, so the strands slide and stretch.","inputs":[],"spec":"95 °C for buffalo mozzarella"},{"name":"Pull off and shape","process":"cut","text":"A thick strand of the hot paste is drawn out and chopped off in portions, which is where the name comes from. Each portion is rolled into a ball or other shape.","inputs":[]},{"name":"Chill and brine","process":"fill","text":"Fresh balls soak in salty water or whey and are packed in liquid. Low-moisture mozzarella for pizza is made drier and keeps far longer than the wet kind.","inputs":["table-salt"]}],"facts":["Fresh mozzarella was traditionally eaten the day it was made, but shredded low-moisture mozzarella can be sold with a shelf life of up to six months.","Stretching removes a lot of calcium, so mozzarella has about 40 percent less calcium than cheddar."],"where":[],"whereNote":null,"sources":[{"title":"Mozzarella","url":"https://en.wikipedia.org/wiki/Mozzarella"},{"title":"Pasta filata","url":"https://en.wikipedia.org/wiki/Pasta_filata"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"vaccine","name":"mRNA vaccine","kind":"product","category":"body-health","title":"How mRNA vaccines are made","url":"https://assemblyline.org/make/vaccine","stations":7,"upstream":23,"downstream":0,"depth":6,"dek":"An mRNA vaccine is built in a tube from a DNA template, not grown in eggs or cells.","answer":"An mRNA vaccine is assembled in vitro. A DNA template carrying the code for one protein is copied by an enzyme into messenger RNA. The RNA is purified and then mixed with fats under controlled conditions so it wraps itself in tiny lipid nanoparticles. The product is filtered, filled into vials and kept cold.","aka":["mRNA vaccine","COVID-19 vaccine","messenger RNA vaccine"],"inputs":["water","air","ethanol","glass-bottle"],"uses":[],"grounds":["water","air","corn","sugarcane","silica-sand","limestone","natural-gas","rock-salt","trona","sugar-beet","crude-oil"],"upstreamSlugs":["water","air","ethanol","glass-bottle","corn","sugarcane","yeast","ethylene","silica-sand","soda-ash","limestone","polyethylene","molasses","naphtha","natural-gas","rock-salt","ammonia","carbon-dioxide","lime","trona","sugar-beet","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Make the DNA template","process":"grow","text":"A ring of plasmid DNA carrying the gene for the target protein is copied inside bacteria in a fermenter. The DNA is later purified and cut so it can serve as a pattern.","inputs":["water","air"]},{"name":"Copy it into RNA","process":"react","text":"An enzyme called T7 RNA polymerase reads the template and builds a strand of messenger RNA from its building blocks. This is in vitro transcription, and it happens in a bioreactor, with no living cells involved.","inputs":[]},{"name":"Remove the template","process":"separate","text":"Enzymes digest the leftover DNA. The RNA then goes through filtration and chromatography to strip out enzymes and fragments.","inputs":[]},{"name":"Cap and tail the strand","process":"react","text":"The RNA gets a protective cap on one end and a tail on the other so cells will read it and it will last long enough to work.","inputs":[]},{"name":"Wrap it in fat","process":"mix","text":"A stream of RNA solution meets a stream of fats dissolved in ethanol inside a mixer. The fats fall out of solution and close around the RNA, forming lipid nanoparticles.","inputs":["ethanol","water"]},{"name":"Purify and concentrate","process":"refine","text":"Cross-flow filtration swaps the liquid for a buffer and removes the alcohol. The nanoparticle suspension is checked for size and RNA content.","inputs":[]},{"name":"Fill and freeze","process":"fill","text":"Sterile lines fill glass vials, which are stoppered, inspected and stored cold. Some mRNA vaccines require ultracold freezers.","inputs":["glass-bottle"]}],"facts":["Lab-made mRNA injected into mouse muscle produced the encoded protein in living tissue, which led to the idea of mRNA vaccines.","Some mRNA vaccines need ultracold storage before distribution, while others do not."],"where":[],"whereNote":null,"sources":[{"title":"mRNA vaccine","url":"https://en.wikipedia.org/wiki/MRNA_vaccine"},{"title":"Insulin","url":"https://en.wikipedia.org/wiki/Insulin"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mustard","name":"Mustard","kind":"product","category":"food","title":"How mustard is made","url":"https://assemblyline.org/make/mustard","stations":6,"upstream":30,"downstream":1,"depth":7,"dek":"The heat in mustard does not exist until water touches the ground seed and two compounds meet.","answer":"Yellow mustard seed is soaked for about two days to soften its hulls, then milled and ground again to remove hard pieces. Mixed with vinegar, water, salt and turmeric, it runs through mills that make the slurry thicker with each pass. Most big producers now use heat to speed things up. Raye's in Maine still ages it for weeks in barrels.","aka":["yellow mustard","Dijon mustard","prepared mustard"],"inputs":["mustard-seed","water","vinegar","table-salt","glass-jar"],"uses":["mayonnaise"],"grounds":["mustard-seed","water","grapes","rock-salt","seawater","corn","sugarcane","barley","silica-sand","limestone","natural-gas","sugar-beet","trona","crude-oil","air"],"upstreamSlugs":["mustard-seed","water","vinegar","table-salt","glass-jar","grapes","ethanol","malted-barley","yeast","rock-salt","seawater","glass","corn","sugarcane","ethylene","barley","molasses","silica-sand","soda-ash","limestone","naphtha","natural-gas","sugar-beet","ammonia","carbon-dioxide","lime","trona","crude-oil","hydrogen","air"],"downstreamSlugs":["mayonnaise"],"steps":[{"name":"Soak the seed","process":"wash","text":"Yellow seeds sit in water for about two days so the hulls break down. Many commercial makers skip this and buy already processed mustard powder.","inputs":["mustard-seed","water"]},{"name":"Mill off the hulls","process":"crush","text":"Milling breaks each soaked seed into tiny pieces and separates it from its hull. A further grind takes out any hard fragments that got through.","inputs":[]},{"name":"Mix the slurry","process":"mix","text":"Crushed seed joins water, distilled vinegar and salt in a large container. Turmeric goes in for the yellow color.","inputs":["vinegar","table-salt"]},{"name":"Run through the stones","process":"grind","text":"At Raye's in Eastport, Maine, the slurry passes through sets of quartz millstones dating to 1900, growing smoother and thicker each time. Cold well water protects the flavor. Most commercial plants use heat instead, for speed and yield.","inputs":[]},{"name":"Age the paste","process":"ferment","text":"The mustard rests for a few weeks before packing, which takes away some of the bite.","inputs":[]},{"name":"Fill jars and bottles","process":"fill","text":"The finished paste is filled into containers and labeled. At Raye's this still happens two jars at a time.","inputs":["glass-jar"]}],"facts":["The oldest known evidence of humans eating mustard is a seed cake from Syria dated to between 9224 and 8753 BC.","The word mustard comes from the Latin mustum, because the Romans mixed ground seed with grape must.","Mustard can act as an emulsifier and keep Hollandaise from curdling."],"where":[],"whereNote":null,"sources":[{"title":"Holly Eats: Raye's Mustard Mill","url":"https://www.hollyeats.com/rayesmustard/"},{"title":"Zingerman's Roadhouse: Raye's yellow mustard from Maine","url":"https://www.zingermansroadhouse.com/2018/06/rayes-yellow-mustard-from-maine/"},{"title":"Sous Chef: How mustard is made","url":"https://www.souschef.co.uk/collections/mustard"},{"title":"Mustard (condiment)","url":"https://en.wikipedia.org/wiki/Mustard_(condiment)"},{"title":"Vinegar","url":"https://en.wikipedia.org/wiki/Vinegar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"mustard-seed","name":"Mustard seed","kind":"raw","category":"farm","title":"How mustard seed is grown","url":"https://assemblyline.org/make/mustard-seed","stations":3,"upstream":0,"downstream":3,"depth":0,"dek":"A mustard seed can be as little as 1 millimeter across and yet close to half oil by weight.","answer":"Mustard seed comes from three plants: black, brown and white mustard. The seeds are 1 to 2 millimeters across and can be nearly half oil by weight. Farmers in cool, temperate regions sow it as a specialty crop, and the plants flower for a few weeks before the seed is harvested and dried.","aka":["mustard seeds","yellow mustard seed","brown mustard seed"],"inputs":[],"uses":["mustard","pickles"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["mustard","pickles","mayonnaise"],"steps":[{"name":"Sow in cool, moist soil","process":"grow","text":"Seeds germinate in eight to ten days when the soil is cold and damp. Mustard prefers temperate regions, and Canada and the northern United States are big growers.","inputs":[]},{"name":"Flower and set seed","process":"grow","text":"Buds appear about five weeks after seedlings emerge and the plant reaches full bloom a week or so later. A longer bloom gives a bigger seed yield.","inputs":[],"spec":"85 to 95 days to maturity"},{"name":"Cut and dry the crop","process":"harvest","text":"Growers harvest when the plant matures, then dry and clean the seed. The seed comes yellowish white to black depending on the plant, and the black seed is the smallest.","inputs":[]}],"facts":["In South Asia the seeds are fried in oil until they pop before going into a dish.","In 2021 Nepal grew the most mustard seed in the world, ahead of Russia and Canada."],"where":[],"whereNote":null,"sources":[{"title":"Mustard seed","url":"https://en.wikipedia.org/wiki/Mustard_seed"},{"title":"Brassica juncea","url":"https://en.wikipedia.org/wiki/Brassica_juncea"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"n95-mask","name":"N95 mask","kind":"product","category":"textiles","title":"How N95 masks are made","url":"https://assemblyline.org/make/n95-mask","stations":8,"upstream":16,"downstream":0,"depth":5,"dek":"Respirators are welded rather than sewn, because a needle hole is a way through the mask.","answer":"An N95 is a stack of nonwovens, with a charged melt-blown filter sandwiched between spunbond layers. Cup styles are pressed between mating mold halves, and folded styles run through ultrasonic welders that fuse layers, cut contours and attach straps without a single needle hole. A bendable nose band and straps complete the seal against the face, and NIOSH approves the finished design.","aka":["N95 respirator","filtering facepiece respirator","FFP2 mask"],"inputs":["polypropylene","aluminum"],"uses":[],"grounds":["crude-oil","coal","bauxite","water","rock-salt","limestone","natural-gas"],"upstreamSlugs":["polypropylene","aluminum","propylene","crude-oil","coal","petroleum-coke","alumina","naphtha","bauxite","caustic-soda","lime","water","hydrogen","rock-salt","limestone","natural-gas"],"downstreamSlugs":[],"steps":[{"name":"Melt-blow the filter web","process":"extrude","text":"Melted polypropylene is pushed through a die with many tiny holes while hot air stretches the strands into extremely fine fibers. They land on a belt as a web, which is wound onto rolls. The filter layer usually carries a charge.","inputs":["polypropylene"]},{"name":"Spin the outer layers","process":"extrude","text":"Outer layers are spunbond polypropylene, spun and laid straight into a web in one continuous process. Melt-blown fabric is fine but weak, so tougher spunbond supports it.","inputs":["polypropylene"]},{"name":"Stack the rolls","process":"laminate","text":"Roll-fed fabric enters an automated line with the filter between the outer layers. Counts vary: many respirators use three layers, and one German FFP2 design, comparable to an N95, uses four with a moisture-absorbing fleece against the skin.","inputs":[]},{"name":"Weld the layers","process":"weld","text":"Ultrasonic welders fuse the stack and cut its contours. A needle and thread can leave a path through the mask, and welding avoids that. The embossed marks on a finished respirator are the welds, running around the rim and holding the nose piece.","inputs":[]},{"name":"Mold or fold the shape","process":"mold","text":"Cup-shaped respirators are formed between male and female mold halves. Many use a stiff shell layer laminated to the filter, while one patent describes a single-layer web stiff enough alone. Flat-fold designs are folded and cut to their finished shape after welding.","inputs":[]},{"name":"Add the nose band","process":"assemble","text":"A soft strip of aluminum or polypropylene runs across the nose. The wearer bends it to the face, which cuts leakage past the welded edge.","inputs":["aluminum"]},{"name":"Attach the straps","process":"weld","text":"Welders fix head straps or loops, or punch reinforced holes for elastic bands. On the German line, two of each machine's four welding stations do only this, fixing left and right loops at once in under a quarter of a second.","inputs":[]},{"name":"Inspect and certify","process":"inspect","text":"Finished respirators leave the line for inspection before packing. To carry the N95 name, a design must be approved by NIOSH as filtering at least 95 percent of airborne particles of 0.3 micrometers.","inputs":[]}],"facts":["N95 means non-resistant to oil, and filtering at least 95 percent of airborne particles of 0.3 micrometers.","Under US law, nobody may call a respirator N95 unless NIOSH has approved it, since the term is a trademark held by the federal health department.","A single German respirator maker expected to turn out 3.5 to 4 million FFP2 masks a week once all its new machines were running."],"where":[],"whereNote":null,"sources":[{"title":"Univent Medical Finds Better Ultrasonic Welds Boost Respirator Quality And Yield, Textile World","url":"https://www.textileworld.com/textile-world/nonwovens-technical-textiles/2021/03/univent-medical-finds-better-ultrasonic-welds-boost-respirator-quality-and-yield/"},{"title":"PPE Manufacturing and Welding Solutions, Branson (Emerson)","url":"https://www.branson.emerson.com/en/branson-ppe-manufacturing-solutions"},{"title":"US7905973B2, Molded monocomponent monolayer respirator","url":"https://patents.google.com/patent/US7905973B2/en"},{"title":"N95 respirator","url":"https://en.wikipedia.org/wiki/N95_respirator"},{"title":"Nonwoven fabric","url":"https://en.wikipedia.org/wiki/Nonwoven_fabric"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"nail","name":"Nail","kind":"product","category":"hardware","title":"How nails are made","url":"https://assemblyline.org/make/nail","stations":6,"upstream":48,"downstream":0,"depth":8,"dek":"In 1913, nine out of ten nails made were wire nails, and a machine still shapes each one in a blink.","answer":"A modern nail starts as a coil of steel wire. A machine straightens the wire, grips it, squeezes one end flat into a head and shears the other end to a point, all within a fraction of a second. The nails are then tumbled clean, often dipped in zinc or glue, and weighed into boxes.","aka":["wire nail","common nail"],"inputs":["steel-wire","zinc","adhesive"],"uses":[],"grounds":["zinc-ore","air","water","sulfur","crude-oil","iron-ore","limestone","dolomite","manganese-ore","natural-gas","rock-salt","coal","quartz","timber"],"upstreamSlugs":["steel-wire","zinc","adhesive","steel","zinc-ore","air","sulfuric-acid","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","sulfur","ethylene","propylene","ammonia","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","naphtha","benzene","rock-salt","coal","quartz","charcoal","timber","toluene"],"downstreamSlugs":[],"steps":[{"name":"Straighten and feed it in","process":"machine","text":"The coil unwinds through a set of offset rollers that take out the curl. A feeder pushes exactly the right length of straight wire into the heading machine.","inputs":["steel-wire"]},{"name":"Squeeze the head flat","process":"forge","text":"Clamps hold the wire while a punch hits the protruding end under high pressure and spreads it into a head. The metal is simply pushed sideways, so nothing is cut away.","inputs":[]},{"name":"Shear the tip","process":"cut","text":"A blade cuts the free end at an angle to leave a point. Other dies can press grooves or ridges into the shank for extra grip in wood.","inputs":[]},{"name":"Tumble them clean","process":"wash","text":"Fresh nails spill into a rotating drum where they rub against each other and shed oil and burrs.","inputs":[]},{"name":"Dip against rust or slippage","process":"coat","text":"Nails for outdoor use are galvanized with a skin of zinc. Others get a coat of glue-like cement that melts from friction as the nail is driven and then grips as it cools.","inputs":["zinc","adhesive"]},{"name":"Weigh and box","process":"package","text":"Nails are sold by weight and by length. Scales fill the boxes, or the nails are strung into collated strips for nail guns.","inputs":[]}],"facts":["By 1913, about 90 percent of manufactured nails were wire nails.","The word penny in nail sizes probably began in medieval England as the price of a hundred nails.","The Roman army left behind seven tons of nails when it abandoned the fortress of Inchtuthil in Scotland."],"where":[],"whereNote":null,"sources":[{"title":"Nail (fastener)","url":"https://en.wikipedia.org/wiki/Nail_(fastener)"},{"title":"Wire drawing","url":"https://en.wikipedia.org/wiki/Wire_drawing"},{"title":"Cold heading","url":"https://en.wikipedia.org/wiki/Cold_heading"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"nail-polish","name":"Nail polish","kind":"product","category":"body-health","title":"How nail polish is made","url":"https://assemblyline.org/make/nail-polish","stations":6,"upstream":41,"downstream":0,"depth":6,"dek":"Nail polish is mostly solvent. As it evaporates, it leaves behind a thin hard film of plastic.","answer":"Nail polish is a solution of a film-forming polymer, usually nitrocellulose, in a fast-evaporating solvent, with resins, a plasticizer and pigment. Cotton or wood cellulose is treated with acids to make the nitrocellulose. The polymer is dissolved, the color is ground in, and the thick liquid is filled into small glass bottles with a steel ball inside.","aka":["nail varnish","nail lacquer","manicure polish"],"inputs":["raw-cotton","wood-pulp","nitric-acid","sulfuric-acid","plasticizer","titanium-dioxide","pigment","glass-bottle"],"uses":[],"grounds":["raw-cotton","timber","water","air","sulfur","titanium-ore","iron-ore","silica-sand","limestone","rock-salt","natural-gas","crude-oil","coal","trona","corn","sugarcane","sugar-beet"],"upstreamSlugs":["raw-cotton","wood-pulp","nitric-acid","sulfuric-acid","plasticizer","titanium-dioxide","pigment","glass-bottle","timber","caustic-soda","water","lime","oxygen","hydrogen-peroxide","ammonia","air","sulfur","naphtha","propylene","titanium-ore","chlorine","coke","iron-ore","carbon-black","silica-sand","soda-ash","limestone","polyethylene","rock-salt","hydrogen","natural-gas","crude-oil","coal","carbon-dioxide","trona","ethylene","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Nitrate the cellulose","process":"react","text":"Cotton or wood-pulp cellulose is nitrated in a bath of nitric and sulfuric acids, washed carefully and kept wet, since the dry material burns very easily.","inputs":["raw-cotton","wood-pulp","nitric-acid","sulfuric-acid"]},{"name":"Dissolve the polymer","process":"mix","text":"Nitrocellulose is stirred into solvents such as ethyl or butyl acetate until it forms a clear, thick lacquer.","inputs":[]},{"name":"Add resin and plasticizer","process":"mix","text":"A resin helps the film stick to the nail, and a plasticizer keeps it flexible. Without them the coat would crack and flake off.","inputs":["plasticizer"]},{"name":"Grind in the color","process":"grind","text":"Pigment is dispersed into some of the lacquer in a mill until it is smooth. Titanium dioxide gives white and pastel shades their opacity.","inputs":["titanium-dioxide","pigment"]},{"name":"Match the shade","process":"inspect","text":"The colored base is combined with the clear lacquer in tanks. A technician compares a painted sample against the master, adjusting until the shades match.","inputs":[]},{"name":"Fill the bottles","process":"fill","text":"Glass bottles are filled, a small mixing ball is dropped in, and a brush cap is screwed on tight so the solvent cannot escape.","inputs":["glass-bottle"]}],"facts":["Ming dynasty nail polish was made from a mixture that included beeswax, egg whites, gelatin, vegetable dyes and gum arabic.","Gel nail polish uses an acrylate copolymer that is cured under light, not nitrocellulose."],"where":[],"whereNote":null,"sources":[{"title":"Nail polish","url":"https://en.wikipedia.org/wiki/Nail_polish"},{"title":"Lipstick","url":"https://en.wikipedia.org/wiki/Lipstick"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"naphtha","name":"Naphtha","kind":"material","category":"chemicals","title":"How naphtha is made","url":"https://assemblyline.org/make/naphtha","stations":5,"upstream":4,"downstream":409,"depth":2,"dek":"Naphtha is the light liquid that boils off crude oil, and steam crackers turn it into the building blocks of plastic.","answer":"Naphtha is made by heating crude oil in a furnace and feeding it into a tall distillation tower. Light liquid collects near the top, above the kerosene and diesel cuts. A hydrogen treater removes sulfur, and the naphtha is sent to a steam cracker to make plastics or to a reformer to be turned into gasoline.","aka":["petroleum naphtha","white gas","light distillate"],"inputs":["crude-oil","water","hydrogen"],"uses":["gasoline","ethylene","propylene","polystyrene","abs-plastic","synthetic-rubber","benzene","p-xylene","plastic","toluene","plasticizer"],"grounds":["crude-oil","water","natural-gas"],"upstreamSlugs":["crude-oil","water","hydrogen","natural-gas"],"downstreamSlugs":["gasoline","ethylene","propylene","polystyrene","abs-plastic","synthetic-rubber","benzene","p-xylene","plastic","toluene","plasticizer","car","car-engine","motorcycle","shampoo","polyethylene","pvc","pet-plastic","ethanol","styrene","polyvinyl-alcohol","ethylene-glycol","polypropylene","acrylic","polycarbonate","epoxy","polyurethane","carbon-fiber","phenol","pvb","acrylic-acid","acetone","surfboard","bike-helmet","ballpoint-pen","polystyrene-foam","foam-cup","smoke-detector","compact-disc","inkjet-printer","lipstick","hearing-aid","thermometer","lego-brick","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","snowboard","action-figure","harmonica","globe","suitcase","high-heels","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","e-reader","graphics-card","remote-control","electric-toothbrush","toothbrush","syringe","rubber","nitrile-glove","chewing-gum","tire","golf-ball","basketball","pencil-eraser","flip-flops","rubber-boots","nylon","spandex","kevlar","duct-tape","led","aa-battery","solar-panel","refrigerator","washing-machine","vacuum-cleaner","nonstick-pan","marker-pen","highlighter","fountain-pen","printer-toner","toaster","roller-skates","tennis-racket","bowling-ball","dice","yo-yo","board-game","jigsaw-puzzle","trading-cards","snow-globe","toy-car","tampon","wet-wipes","asthma-inhaler","prosthetic-leg","wheelchair","light-switch","power-outlet","seat-belt","backpack","eyeglass-frame","microphone","umbrella","nail-polish","yoga-mat","hairspray","vinyl-floor","cellulose-acetate","locomotive","toothpaste","hip-implant","adhesive","plastic-bag","lithium-ion-cell","glass-bottle","frozen-peas","bubble-wrap","plastic-wrap","zip-bag","paper-cup","thermos","ski","frisbee","sanitary-pad","power-cable","car-battery","diaper","credit-card","dishwasher","garden-hose","football","volleyball","fashion-doll","inflatable-pool-toy","chain-link-fence","pvc-pipe","vinyl-record","polyester","plastic-bottle","drum-kit","bottled-water","deodorant","perfume","vaccine","ink","vanilla-extract","vinegar","gin","lacquer","super-glue","port-wine","insect-repellent","air-freshener","mouthwash","banknote","mascara","electric-kettle","plastic-straw","clear-tape","office-chair","cotton-swab","dental-floss","loudspeaker","baseball-cap","carpet","rope","n95-mask","paint","lcd-screen","sunglasses","led-bulb","drone","eyeglass-lens","blender","smartwatch","digital-camera","camera-lens","printed-circuit-board","wind-turbine","electric-motor","rebar","aluminum-can","airplane","fishing-rod","adhesive-bandage","pacemaker","skateboard","soccer-ball","hardwood-floor","water-heater","sofa","underwear","leggings","swimsuit","raincoat","sneaker","mattress","satellite","bicycle","golf-club","kite","aspirin","acetaminophen","billiard-ball","brake-pad","phenolic-resin","windshield","superabsorbent-polymer","shoelace","pencil","shipping-container","tennis-ball","baseball","cricket-bat","dumbbell","treadmill","ladder","wheelbarrow","fire-extinguisher","hiking-boots","leather-shoe","electric-car","airbag","guitar","violin","velcro","ukulele","drumstick","eyeshadow","aluminum-window-frame","down-jacket","handbag","flag","socks","zipper","canoe","pinball-machine","ev-battery","nail","insulation","popcorn","piano","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","staple","ice-skates","dartboard","chess-set","cello","kitchen-sponge","roof-shingle","double-glazed-window","sailboat","dress-shirt","suit","wallet","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","cotton-candy","pillow","smartphone","penicillin","insulin","ketchup","cola","sparkling-water","beer","wine","champagne","whiskey","vodka","rum","tequila","sake","hard-cider","hot-sauce","soda","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","prosecco","non-alcoholic-beer","candy-cane","hoodie","curtain","button","thread","teddy-bear","sunscreen","detergent","bleach","vitamin-c","dish-soap","hair-dye","foundation-makeup","cough-syrup","tin-can","wallpaper","candy-coated-chocolate","floor-tile","newspaper","t-shirt","ice-cream","white-chocolate","caramel","mayonnaise","mustard","salsa","pickles","electric-guitar","trumpet","chopsticks","saxophone","felt-hat","baseball-bat","microwave-oven","scissors","mirror","container-ship","water-bottle","ceiling-fan","coil-spring","hammer","gas-cylinder","neon-sign","suspension-bridge-cable","subway-train","leather-belt","hard-drive","solid-state-drive","rocket","elevator","air-conditioner","concrete","skyscraper","energy-drink","light-beer","photoresist","jeans","fireworks","cake-mix","soap","paperclip","donut","corn-flakes","crayon","candle","canned-meat","fish-sticks","facial-tissue","silk-tie","winter-gloves","blanket","sweater","towel","flour","condensed-milk","baby-formula","coconut-milk","canned-soup","padlock","microchip","memory-chip","indium-tin-oxide","bread","instant-noodles","tortilla","croissant","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","modeling-clay","licorice","toffee","oled-screen"],"steps":[{"name":"Wash the crude","process":"wash","text":"Crude oil is mixed with fresh water to dissolve salt, then spun or charged in an electric field so that the salty water drops out. Salt left in the oil would corrode the equipment ahead.","inputs":["crude-oil","water"]},{"name":"Heat it in a furnace","process":"melt","text":"The crude flows through coiled pipes inside a furnace and leaves as a hot mix of liquid and vapor. It is pumped into the bottom of the distillation tower.","inputs":[]},{"name":"Split it in a tower","process":"refine","text":"Vapor rises through a tall column of trays, cooling as it climbs. Each fraction condenses at its own height, and the light naphtha collects near the top, well above the heavier kerosene and diesel.","inputs":[]},{"name":"Strip out sulfur","process":"react","text":"Naphtha is passed over a catalyst with hydrogen, which turns sulfur compounds into hydrogen sulfide gas that is removed. Later catalysts are sensitive to sulfur, so this protects them.","inputs":["hydrogen"]},{"name":"Send it to crackers or reformers","process":"package","text":"Steam crackers use naphtha to make plastic building blocks, and reformers use it to make high-octane gasoline blending stock. A small share ends up in camp stoves as white gas.","inputs":[]}],"facts":["Naphtha has such a low boiling point that it is sold in camping stores as white gas for stoves and lanterns.","Crude oil was distilled by Persian chemists, with clear descriptions in handbooks, centuries before modern refineries."],"where":[],"whereNote":null,"sources":[{"title":"Naphtha","url":"https://en.wikipedia.org/wiki/Naphtha"},{"title":"Oil refinery","url":"https://en.wikipedia.org/wiki/Oil_refinery"},{"title":"Hydrodesulfurization","url":"https://en.wikipedia.org/wiki/Hydrodesulfurization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"natural-gas","name":"Natural gas","kind":"raw","category":"ground","title":"How natural gas is produced","url":"https://assemblyline.org/make/natural-gas","stations":4,"upstream":0,"downstream":528,"depth":0,"dek":"Natural gas is about 95% methane, and it has to be stripped of water and other gases before anyone can burn it.","answer":"Natural gas forms when buried marine microorganisms are cooked for millions of years without oxygen. Wells tap the gas in rock, and it flows up the pipe under its own pressure. Plants then strip out water, hydrogen sulfide, carbon dioxide and heavier hydrocarbons, leaving methane for pipelines or for liquefying into LNG.","aka":["methane","fossil gas"],"inputs":[],"uses":["deodorant","ammonia","hydrogen","ethylene","ptfe","manganese","methanol","carbon-dioxide","plastic","propane","lng","synthetic-diamond","pentane","carbon-monoxide","polyvinylpyrrolidone"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["deodorant","ammonia","hydrogen","ethylene","ptfe","manganese","methanol","carbon-dioxide","plastic","propane","lng","synthetic-diamond","pentane","carbon-monoxide","polyvinylpyrrolidone","soda-ash","nitric-acid","fertilizer","abs-plastic","nylon","acrylic","carbon-fiber","kevlar","led","platinum","baking-soda","caramel-color","refrigerant","hair-dye","melamine-resin","iridium","acetaminophen","vitamin-c","naphtha","gasoline","diesel","jet-fuel","paraffin-wax","polysilicon","tungsten","window-glass","margarine","rocket","benzene","hydrochloric-acid","hexane","germanium","motor-oil","hydrogen-peroxide","shampoo","polyethylene","pvc","pet-plastic","polystyrene","synthetic-rubber","ethanol","styrene","polyvinyl-alcohol","ethylene-glycol","razor-blade","nonstick-pan","raincoat","thermometer","lithium-ion-cell","aa-battery","steel","silicone","glycerin","acetic-anhydride","biodiesel","formaldehyde","aspirin","decaf-coffee","cola","sparkling-water","beer","popping-candy","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","caffeine","duct-tape","solar-panel","refrigerator","washing-machine","vacuum-cleaner","marker-pen","highlighter","fountain-pen","printer-toner","toaster","roller-skates","tennis-racket","bowling-ball","dice","yo-yo","board-game","jigsaw-puzzle","trading-cards","globe","snow-globe","toy-car","tampon","wet-wipes","asthma-inhaler","prosthetic-leg","wheelchair","light-switch","power-outlet","smoke-detector","seat-belt","backpack","eyeglass-frame","microphone","e-reader","umbrella","steel-scrap","air-freshener","hairspray","polystyrene-foam","foam-cup","detergent","fiberglass","lithium-carbonate","chromium","glass","glass-bottle","smartphone-glass","marble-toy","instant-noodles","stained-glass","vanadium","nail-polish","polyurethane","lipstick","hearing-aid","lego-brick","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","ballpoint-pen","snowboard","action-figure","harmonica","suitcase","high-heels","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","toothbrush","mascara","drone","tire","airbag","guitar","violin","basketball","bike-helmet","velcro","dishwasher","office-chair","volleyball","kite","fashion-doll","ukulele","drumstick","eyeshadow","dental-floss","aluminum-window-frame","underwear","leggings","swimsuit","down-jacket","handbag","hiking-boots","flag","socks","carpet","zipper","rope","paint","adhesive","lcd-screen","sunglasses","lacquer","wind-turbine","satellite","airplane","bicycle","golf-club","fishing-rod","brake-pad","canoe","led-bulb","pinball-machine","hard-drive","pretzel","frozen-pizza","bagel","crackers","cake-mix","fire-extinguisher","rum","air-conditioner","laminate-floor","flour","propylene","p-xylene","toluene","plasticizer","car","car-engine","motorcycle","locomotive","jet-engine","sunscreen","pencil","chewing-gum","turbine-blade","crayon","candle","cork-stopper","mdf","match","silicon-wafer","light-bulb","tungsten-carbide","drill-bit","mirror","skyscraper","windshield","double-glazed-window","phenol","spandex","acetone","trichlorosilane","vegetable-oil","optical-fiber","wood-pulp","silk","towel","toothpaste","hip-implant","plastic-bag","frozen-peas","bubble-wrap","plastic-wrap","zip-bag","paper-cup","thermos","ski","frisbee","sanitary-pad","power-cable","car-battery","flip-flops","diaper","credit-card","garden-hose","football","yoga-mat","inflatable-pool-toy","chain-link-fence","pvc-pipe","vinyl-floor","vinyl-record","polyester","plastic-bottle","drum-kit","bottled-water","surfboard","compact-disc","syringe","rubber","nitrile-glove","golf-ball","pencil-eraser","rubber-boots","perfume","vaccine","ink","vanilla-extract","vinegar","gin","super-glue","port-wine","insect-repellent","mouthwash","pvb","banknote","ev-battery","smartphone","smartwatch","digital-camera","electric-motor","transformer","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","container-ship","shipping-container","elevator","skateboard","wine-barrel","ice-skates","dumbbell","saxophone","barbed-wire","hammer","wrench","gas-cylinder","spark-plug","subway-train","leather-belt","loudspeaker","condom","contact-lens","pressure-cooker","blender","foundation-makeup","soap","cough-syrup","gelatin-capsule","ibuprofen","cellulose-acetate","billiard-ball","phenolic-resin","stainless-steel","cast-iron-pan","printed-circuit-board","roof-shingle","sailboat","safety-pin","faucet","stent","nichrome","leather","oled-screen","camera-sensor","microwave-oven","eyeglass-lens","indium-tin-oxide","glass-jar","water-heater","floor-tile","neon-sign","penicillin","insulin","ketchup","wine","champagne","whiskey","vodka","tequila","sake","hard-cider","hot-sauce","kombucha","bourbon","scotch","cognac","mezcal","mead","prosecco","adhesive-bandage","pacemaker","soccer-ball","hardwood-floor","sofa","sneaker","mattress","electric-car","jeans","electric-kettle","wallpaper","wooden-chair","water-bottle","ceiling-fan","dartboard","coil-spring","wheelbarrow","suspension-bridge-cable","nail","insulation","popcorn","piano","tennis-ball","baseball","paper-straw","paper-bag","pizza-box","door","clear-tape","staple","cricket-bat","chess-set","cello","kitchen-sponge","cotton-swab","dress-shirt","suit","wallet","camera-lens","plywood","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","leather-shoe","baseball-cap","tin-can","electric-guitar","trumpet","chopsticks","felt-hat","baseball-bat","bread","tortilla","croissant","donut","sandwich-cookie","chicken-nuggets","baguette","sourdough","fish-sticks","modeling-clay","licorice","polypropylene","polycarbonate","epoxy","acrylic-acid","treadmill","microchip","memory-chip","solar-cell","saw-blade","shoelace","mayonnaise","peanut-butter","potato-chips","french-fries","canned-tuna","baby-formula","oat-milk","wooden-spoon","paper","facial-tissue","rayon","silk-tie","winter-gloves","cotton-candy","pillow","candy-cane","hoodie","curtain","button","thread","teddy-bear","bleach","dish-soap","ladder","aluminum-can","candy-coated-chocolate","newspaper","t-shirt","ice-cream","white-chocolate","caramel","mustard","salsa","pickles","hinge","shovel","wire-rope","screw","paperclip","needle","clothespin","slinky","guitar-string","bolt","chain","concrete","photoresist","kitchen-knife","fork","solid-state-drive","sauerkraut","jam","hazelnut-spread","fireworks","corn-flakes","canned-meat","condensed-milk","coconut-milk","canned-soup","plastic-straw","n95-mask","superabsorbent-polymer","drywall","egg-carton","blanket","sweater","toffee"],"steps":[{"name":"Drill into the gas pocket","process":"drill","text":"A well is bored into rock that traps gas, or into an oil field where gas is dissolved in the oil. Gas from oil wells is called associated gas.","inputs":[]},{"name":"Let pressure carry it up","process":"drill","text":"Reservoir pressure pushes the gas to the surface. In some formations, pressurized liquid is pumped in to open up the rock, so that the gas flows more easily.","inputs":[]},{"name":"Strip out the impurities","process":"refine","text":"Raw gas almost always has to be processed before it is burned. Water, carbon dioxide, hydrogen sulfide and sometimes helium and nitrogen are removed, and heavier hydrocarbons such as ethane, propane and butane are separated and sold separately.","inputs":[]},{"name":"Send it down the pipe","process":"package","text":"Cleaned gas goes into pipelines. For shipping across oceans, it can be cooled into liquefied natural gas, which takes far less space.","inputs":[]}],"facts":["The hydrogen sulfide removed from natural gas may be converted into pure sulfur.","The world's largest gas field is South Pars/North Dome, offshore and shared between Iran and Qatar."],"where":[],"whereNote":null,"sources":[{"title":"Natural gas","url":"https://en.wikipedia.org/wiki/Natural_gas"},{"title":"Hydraulic fracturing","url":"https://en.wikipedia.org/wiki/Hydraulic_fracturing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"natural-graphite","name":"Natural graphite","kind":"raw","category":"ground","title":"How graphite is mined","url":"https://assemblyline.org/make/natural-graphite","stations":4,"upstream":0,"downstream":1,"depth":0,"dek":"Graphite is so soft it smears onto the waste rock around it and drags that rock along during cleaning.","answer":"Graphite forms when carbon-rich sedimentary rock or coal is cooked deep underground. Miners reach it by open pit or tunnel, then crush the ore and float the graphite off in tanks of froth. Because graphite coats the waste rock, the crushing and floating may repeat up to seven times, or acid may dissolve what is left.","aka":["plumbago","black lead"],"inputs":[],"uses":["pencil"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["pencil"],"steps":[{"name":"Dig out the ore","process":"mine","text":"Deposits are worked by both open pits and underground tunnels. Flake graphite comes from metamorphic rock, lump graphite from veins, and amorphous graphite from coal that was baked by heat underground.","inputs":[]},{"name":"Crush the rock","process":"crush","text":"Ore is broken down to free the graphite from the surrounding rock. Crews handle coarse flakes carefully at this point, since large flakes are worth more than fine powder.","inputs":[]},{"name":"Float it on froth","process":"separate","text":"In flotation tanks, light graphite rises with the froth and the waste rock sinks. Graphite's softness makes this harder than it sounds. It smears over waste particles and carries them up too, so the concentrate is reground and floated again, up to seven times.","inputs":[],"spec":"up to 7 rounds"},{"name":"Sort by flake size","process":"separate","text":"The finished concentrate is screened into size fractions and tested for carbon content. Blends are then made to order, because a crucible maker and a brake-lining maker want different flakes.","inputs":[]}],"facts":["Modern froth flotation, a process now used across mining, traces its beginnings to graphite and an 1877 German patent.","Graphite is carbon, the same element as diamond, with its atoms arranged in sheets that slide past one another."],"where":[],"whereNote":null,"sources":[{"title":"Graphite","url":"https://en.wikipedia.org/wiki/Graphite"},{"title":"Pencil","url":"https://en.wikipedia.org/wiki/Pencil"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"natural-latex","name":"Natural rubber latex","kind":"raw","category":"farm","title":"How natural rubber latex is harvested","url":"https://assemblyline.org/make/natural-latex","stations":3,"upstream":0,"downstream":43,"depth":0,"dek":"Rubber trees are tapped before dawn, because the milky sap keeps dripping longer while the air is still cool.","answer":"Natural rubber latex is the white sap of the Amazonian rubber tree. Tappers shave a thin half-spiral groove into the bark, and the latex runs down it into a cup. They work in the cool of the night or early morning so it drips longer before it clots, and ammonia can keep it liquid.","aka":["rubber tapping","rubber sap","Para rubber latex","Hevea latex"],"inputs":[],"uses":["condom","rubber","balloon","duct-tape","tire","hockey-puck","rubber-band","pencil-eraser","rubber-boots"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["condom","rubber","balloon","duct-tape","tire","hockey-puck","rubber-band","pencil-eraser","rubber-boots","computer-keyboard","vacuum-cleaner","electric-kettle","pencil","shipping-container","tennis-ball","baseball","soccer-ball","ski","snowboard","roller-skates","golf-club","football","volleyball","cricket-bat","dumbbell","treadmill","wheelchair","ladder","wheelbarrow","fire-extinguisher","hiking-boots","high-heels","loudspeaker","inkjet-printer","electric-toothbrush","sneaker","leather-shoe","umbrella","car","electric-car","bicycle","motorcycle","laptop"],"steps":[{"name":"Raise the plantation trees","process":"grow","text":"Rubber trees grown on plantations have an economic life of around 32 years. Up to 7 years of that is an immature phase, and the remaining 25 or so are the years the tree is tapped.","inputs":[],"spec":"about 25 productive years"},{"name":"Slice a spiral groove","process":"harvest","text":"The tapper peels a thin strip of bark away along a downward half spiral with a hooked knife, cutting to a depth of 6.4 mm. A tree needs to be about 150 mm across before it is tapped, and it is never cut down to get the latex.","inputs":[],"spec":"6.4 mm deep"},{"name":"Catch the milky drip","process":"harvest","text":"Latex runs along the groove into a cup, and a fresh panel will keep yielding for up to five hours. Work happens at night or early morning so the latex drips longer before it coagulates and seals the cut. An ammonia solution can be added to stop it from clotting.","inputs":[]}],"facts":["In 1876 Henry Wickham smuggled 70,000 rubber tree seeds out of Brazil to Kew Gardens, and only 2,400 of them germinated.","More than 29 million tonnes of rubber were produced in 2022, and over half of it was synthetic, so oil prices pull on the price of the natural kind.","Slaughter tapping, a destructive late nineteenth-century method, pulled out large amounts of latex in a short time."],"where":[],"whereNote":null,"sources":[{"title":"Rubber tapping","url":"https://en.wikipedia.org/wiki/Rubber_tapping"},{"title":"Natural rubber","url":"https://en.wikipedia.org/wiki/Natural_rubber"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"neodymium-magnet","name":"Neodymium magnet","kind":"material","category":"metals","title":"How neodymium magnets are made","url":"https://assemblyline.org/make/neodymium-magnet","stations":8,"upstream":9,"downstream":6,"depth":3,"dek":"The strongest permanent magnets sold are sintered from powder, aligned by an electromagnet while they are pressed.","answer":"A neodymium magnet is made from an alloy of neodymium, iron and boron. The alloy is melted, cast into ingots, milled to a fine powder, pressed in a strong magnetic field so the grains line up, and sintered into dense blocks. The blocks are heat-treated, cut, plated against corrosion, and magnetized last.","aka":["NdFeB magnet","neo magnet","rare-earth magnet"],"inputs":["rare-earth-ore","nickel","zinc"],"uses":["headphones","wind-turbine","wireless-earbuds","loudspeaker","microphone","electric-toothbrush"],"grounds":["rare-earth-ore","nickel-ore","zinc-ore","air","sulfur","water"],"upstreamSlugs":["rare-earth-ore","nickel","zinc","nickel-ore","sulfuric-acid","zinc-ore","air","sulfur","water"],"downstreamSlugs":["headphones","wind-turbine","wireless-earbuds","loudspeaker","microphone","electric-toothbrush"],"steps":[{"name":"Melt the alloy","process":"melt","text":"Neodymium, extracted from rare earth ore, is melted in a furnace with iron and boron. The target compound is Nd2Fe14B, which has a tetragonal crystal structure.","inputs":["rare-earth-ore"]},{"name":"Cast ingots","process":"cast","text":"Molds take the melt, and it cools to form ingots of the alloy.","inputs":[]},{"name":"Mill to powder","process":"crush","text":"Ingots are pulverized and milled to a fine powder, each grain a tiny crystal.","inputs":[]},{"name":"Align and press the powder","process":"press","text":"Grains of the microcrystalline powder are lined up in a powerful magnetic field during manufacture. Each crystal magnetizes easily along one axis, and holding them parallel is what gives the finished block its strength.","inputs":[]},{"name":"Sinter into dense blocks","process":"fire","text":"The pressed powder is heated until the grains fuse into a dense solid block without melting the whole mass.","inputs":[]},{"name":"Heat-treat and cut","process":"heat-treat","text":"The blocks are heat-treated, then cut to the shape the customer needs.","inputs":[]},{"name":"Plate the surface","process":"coat","text":"Sintered magnets corrode along their grain boundaries and can crumble into powder. A coating of nickel, nickel-copper-nickel or zinc is the standard defense.","inputs":["nickel","zinc"]},{"name":"Magnetize it last","process":"assemble","text":"Only at the end is the finished block magnetized. Bonded magnets, a second kind, instead use melt-spun ribbon crushed and mixed with polymer, then molded.","inputs":[]}],"facts":["General Motors and Sumitomo Special Metals discovered the neodymium-iron-boron compound independently, almost at the same time, in 1984.","By energy per volume, a neodymium magnet is about 18 times stronger than an ordinary ferrite magnet.","Above 100 °C the coercivity of a neodymium magnet drops sharply, and its Curie temperature is around 320 °C."],"where":[{"place":"China","share":"at least 85% of output"},{"place":"Japan","share":"about 7%"}],"whereNote":"2024 estimate, of global NdFeB magnet output of roughly 220,000 to 240,000 tonnes.","sources":[{"title":"Neodymium magnet","url":"https://en.wikipedia.org/wiki/Neodymium_magnet"},{"title":"Rare-earth magnet","url":"https://en.wikipedia.org/wiki/Rare-earth_magnet"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"neon","name":"Neon","kind":"material","category":"chemicals","title":"How neon is made","url":"https://assemblyline.org/make/neon","stations":6,"upstream":2,"downstream":1,"depth":2,"dek":"One pound of the gas takes 88,000 pounds of a rare mix drawn from a huge air plant. Air is its only source.","answer":"All of it comes out of the atmosphere, which holds just 18.2 parts per million. Air separation plants liquefy air for oxygen and nitrogen, and this gas stays behind in the small fraction that refuses to condense. A side column concentrates it, then charcoal removes helium and added oxygen burns off hydrogen, before it is bottled for lasers, chip plants and glowing signs.","aka":["neon gas","Ne"],"inputs":["air","oxygen"],"uses":["neon-sign"],"grounds":["air"],"upstreamSlugs":["air","oxygen"],"downstreamSlugs":["neon-sign"],"steps":[{"name":"Filter and compress air","process":"press","text":"Air is cleaned of dust and compressed. Water condenses out between stages, and a molecular sieve bed catches the remaining water vapor and carbon dioxide, which would freeze and plug the cold equipment.","inputs":["air"]},{"name":"Liquefy in the cold box","process":"chill","text":"Inside an insulated enclosure, heat exchangers and expansion turbines cool the air until most of it turns liquid. This gas boils at −246 °C, so it stays as vapor while nitrogen condenses at −195.8 °C.","inputs":[]},{"name":"Tap the top condenser","process":"separate","text":"A gas mix of mainly nitrogen, neon, helium and hydrogen is withdrawn from the main condenser at the top of the high-pressure column. It is a tiny stream from a very large plant.","inputs":[]},{"name":"Rectify in a side column","process":"refine","text":"The mix enters the bottom of a separate side column, where rectification concentrates the rare gas. What comes out is a crude stream still carrying helium and hydrogen.","inputs":[]},{"name":"Remove helium and hydrogen","process":"separate","text":"Contact with activated charcoal separates out the helium. Added oxygen reacts with the hydrogen to form water, which is then condensed away.","inputs":["oxygen"]},{"name":"Bottle the pure gas","process":"fill","text":"Finished gas is compressed into cylinders for buyers such as sign makers and laser makers. Chip makers buy it too, and some changed suppliers after a price spike of about 600% in 2014.","inputs":[]}],"facts":["Before 2022, about 70% of the world's neon was produced in Ukraine, as a by-product of steel production in Russia.","Neon tubes failed as home lighting because homeowners objected to the color, and they found their market in advertising signs from 1912.","Earth's atmosphere holds 1 part neon in 55,000 by volume."],"where":[],"whereNote":null,"sources":[{"title":"Neon","url":"https://en.wikipedia.org/wiki/Neon"},{"title":"Air separation","url":"https://en.wikipedia.org/wiki/Air_separation"},{"title":"Neon (Britannica)","url":"https://www.britannica.com/science/neon-chemical-element"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"neon-sign","name":"Neon sign","kind":"product","category":"minerals","title":"How neon signs are made","url":"https://assemblyline.org/make/neon-sign","stations":9,"upstream":69,"downstream":0,"depth":10,"dek":"A neon sign is a glass tube bent by hand over a flame, emptied of air and refilled with a trace of gas.","answer":"Straight lead-glass tubes 8 to 15 mm across soften in about 30 seconds over a ribbon burner, then get bent by hand against a drawn pattern, with a puff of air keeping the bore round. Electrodes are fused on. A pump and a blast of high current clear the air and impurities, and neon or argon goes in before sealing.","aka":["neon light","neon tube"],"inputs":["glass","mercury","neon","argon","paint"],"uses":[],"grounds":["silica-sand","limestone","cinnabar","air","water","rock-salt","trona","titanium-ore","iron-ore","sulfur","natural-gas","corn","coal","crude-oil","tin-ore","sugarcane","soybeans","rapeseed","clay","sugar-beet","dolomite","manganese-ore","quartz","timber"],"upstreamSlugs":["glass","mercury","neon","argon","paint","silica-sand","soda-ash","limestone","cinnabar","air","oxygen","water","titanium-dioxide","pigment","acrylic","tin-can","rock-salt","ammonia","carbon-dioxide","lime","trona","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","carbon-black","sulfur","propylene","methanol","tinplate","lacquer","ink","natural-gas","corn","yeast","coal","crude-oil","naphtha","steel","tin","ethanol","vegetable-oil","phenolic-resin","molasses","hydrogen","pig-iron","magnesium","steel-scrap","manganese","tin-ore","sugarcane","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","sugar-beet","dolomite","silicon","propane","manganese-ore","benzene","quartz","charcoal","timber","toluene"],"downstreamSlugs":[],"steps":[{"name":"Bend over a ribbon burner","process":"blow","text":"The bender marks the tube against a pattern laid out on a fire-resistant sheet, heats each spot in a propane flame, and bends it gently. Blowing into the open end restores the original diameter, and each bend is checked against the pattern.","inputs":["glass"],"spec":"about 30 seconds at 1200 F"},{"name":"Fuse on the electrodes","process":"weld","text":"A hand torch melts an electrode onto each end. These are lead glass with a small metal shell and two wires running through. One end is sealed and the other stays open.","inputs":[]},{"name":"Add a side passage","process":"weld","text":"A crossfire burner makes a small bubble of glass that opens into the unsealed electrode, the way in for the gas. Argon tubes get a drop of mercury here to brighten their light.","inputs":["mercury"]},{"name":"Pump and bombard","process":"refine","text":"An end torch fuses the passage to a vacuum system. While the pump draws out the air, a bombarding transformer forces high current through the tube, which clears impurities.","inputs":[],"spec":"15,000 to 25,000 V, 500 to 1000 mA"},{"name":"Fill with gas","process":"fill","text":"A little gas goes in at low pressure, between 3 and 20 Torr. Clear tubing gives red with neon and steel blue with argon. Phosphor coatings inside the glass stretch that to many more colors.","inputs":["neon","argon"],"spec":"3 to 20 Torr"},{"name":"Seal off the passage","process":"weld","text":"The crossfire burner takes off the side passage and closes the electrode, trapping the gas. In argon tubes the mercury has to drop into the electrode first.","inputs":[]},{"name":"Black out the back","process":"coat","text":"Stretches of tube that should stay dark get black paint, brushed even so the lettering stands out. One shop dips the whole back of the tube.","inputs":["paint"]},{"name":"Burn in the tube","process":"inspect","text":"The finished tube burns for about 30 minutes at high voltage. That dries the paint and turns the liquid mercury into vapor that spreads through the whole length.","inputs":[]},{"name":"Mount and wire up","process":"assemble","text":"Clear clips hold the tube to a plexiglass backing, and its electrode wires connect to a transformer that steps wall current up to several thousand volts.","inputs":[]}],"facts":["William Ramsay and Morris W. Travers of Britain discovered neon in 1898.","Earle C. Anthony bought two neon signs from Georges Claude in 1923 for a Packard dealership in Los Angeles, and people stopped to stare.","Neon tubes can be as long as 30 meters with standard electrical equipment."],"where":[],"whereNote":null,"sources":[{"title":"Neon lighting","url":"https://en.wikipedia.org/wiki/Neon_lighting"},{"title":"Neon sign","url":"https://en.wikipedia.org/wiki/Neon_sign"},{"title":"How Neon Signs are Made, Bright Neon Signs","url":"https://www.brightneonsigns.com/pages/making-a-neon-sign"},{"title":"How Neon is Made and a Guide to Choosing Colors, Patrick Nash Design","url":"https://www.patricknashdesign.com/blog/how-neon-is-made-and-a-guide-to-choosing-colors"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"newspaper","name":"Newspaper","kind":"product","category":"wood-paper","title":"How newspapers are printed","url":"https://assemblyline.org/make/newspaper","stations":6,"upstream":50,"downstream":0,"depth":8,"dek":"A newspaper is printed on a continuous ribbon of cheap paper that runs through the press like a flag in a gale.","answer":"Newspapers are printed on newsprint, a cheap, strong wood-pulp paper that comes in huge rolls. Photographic plates carry each page, ink moves from plate to rubber blanket to paper, and cutters and folders slice and fold the moving web into finished copies. Bundles are loaded onto trucks.","aka":["daily paper","the press","broadsheet"],"inputs":["paper","aluminum","ink","water"],"uses":[],"grounds":["water","kaolin","limestone","crude-oil","coal","timber","bauxite","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","natural-gas","sugar-beet"],"upstreamSlugs":["paper","aluminum","ink","water","wood-pulp","kaolin","limestone","crude-oil","coal","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","bauxite","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","ethylene","rock-salt","hydrogen","benzene","propylene","methanol","molasses","naphtha","natural-gas","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Roll out the newsprint","process":"roll","text":"Mills make newsprint mostly from wood pulp, and it goes to the press as a giant roll. It is cheap and strong enough to survive a fast web press, but it yellows with age because of the lignin in it.","inputs":["paper"]},{"name":"Image the plates","process":"etch","text":"Each page is converted into the four process colors, and a plate is made for each one. Light transfers the page onto a thin aluminum sheet, and the sheet is chemically treated so that ink clings to the image areas only.","inputs":["aluminum"]},{"name":"Ink the plates","process":"print","text":"Plates are curved around cylinders on the press. Oil-based ink sticks to the image and water-dampened blank areas repel it, because oil and water do not mix.","inputs":["ink","water"]},{"name":"Offset onto the web","process":"print","text":"The inked image is pressed onto a rubber blanket, and the blanket prints on the paper. Two blankets squeeze the web between them to print both sides at once, and the soft rubber hugs the rough paper surface.","inputs":[]},{"name":"Cut and fold the web","process":"cut","text":"The printed ribbon runs on to a folder that slices it into pages and folds the sections together at speed.","inputs":[]},{"name":"Count and bundle","process":"package","text":"Finished copies are counted into stacks, strapped and sent by conveyor to loading docks. Zoned editions of the same paper can carry different ads and local pages for each delivery area.","inputs":[]}],"facts":["Charles Fenerty of Nova Scotia invented newsprint in 1844 by making paper from wood, and showed a sample to the Acadian Recorder in Halifax.","A good offset plate can print more than a million impressions."],"where":[],"whereNote":null,"sources":[{"title":"Newspaper","url":"https://en.wikipedia.org/wiki/Newspaper"},{"title":"Newsprint","url":"https://en.wikipedia.org/wiki/Newsprint"},{"title":"Offset printing","url":"https://en.wikipedia.org/wiki/Offset_printing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"nichrome","name":"Nichrome","kind":"material","category":"metals","title":"How nichrome is made","url":"https://assemblyline.org/make/nichrome","stations":8,"upstream":29,"downstream":2,"depth":6,"dek":"The glowing wire in a toaster protects itself. Heat grows a skin of chromium oxide that keeps out the air.","answer":"Eighty percent nickel and twenty percent chromium give the classic grade of this heating alloy, patented back in 1906. It resists current about 66 times better than copper. One supplier melts it under vacuum, anneals the ingot, forges and rolls it hot, cold-draws it through many passes, anneals again, then pickles and polishes the wire.","aka":["nickel-chromium","NiCr","resistance wire","heating wire"],"inputs":["nickel","chromium"],"uses":["electric-kettle","toaster"],"grounds":["nickel-ore","chromite","limestone","air","water","sulfur","coal","rock-salt","trona","crude-oil","natural-gas","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["nickel","chromium","nickel-ore","sulfuric-acid","chromite","coke","soda-ash","limestone","air","water","aluminum","sulfur","coal","rock-salt","ammonia","carbon-dioxide","lime","trona","crude-oil","petroleum-coke","alumina","natural-gas","corn","yeast","bauxite","caustic-soda","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["electric-kettle","toaster"],"steps":[{"name":"Melt the alloy charge","process":"melt","text":"Nickel and chromium go into a vacuum induction furnace, with traces of iron, silicon or manganese at the supplier FANMETAL. ASTM and DIN standards specify the percentages. The A grade is 80% nickel and 20% chromium by mass.","inputs":["nickel","chromium"]},{"name":"Soak the ingot","process":"heat-treat","text":"The solid ingot is annealed so that metals which separated as it cooled spread evenly through it again.","inputs":[]},{"name":"Forge and roll hot","process":"forge","text":"Hot ingots are forged, then rolled. A solution treatment between these steps refines the grain and relieves internal stress. The alloy's good ductility allows this and the drawing to come.","inputs":[]},{"name":"Draw to thin wire","process":"draw","text":"Rod is pulled cold through narrowing dies in many passes until it reaches a set electrical resistance per meter. Standards hold wire over 0.127 millimeters to within 5 percent of that value.","inputs":[]},{"name":"Anneal under vacuum","process":"heat-treat","text":"Cold drawing leaves the wire hard. A vacuum anneal gives back its plasticity.","inputs":[]},{"name":"Pickle and polish","process":"wash","text":"Pickling strips off oxide scale, and electrolytic polishing leaves a smooth surface.","inputs":[]},{"name":"Coil or flatten","process":"roll","text":"Round wire is wound tightly into coils or flattened into ribbon 0.3 to 4 millimeters wide, a form toasters wind around a mica card. Coils can relax to up to 10 times their wound length in use.","inputs":[]},{"name":"Test the batch","process":"inspect","text":"FANMETAL runs composition analysis, mechanical tests, non-destructive testing and visual inspection before shipping.","inputs":[]}],"facts":["Albert Marsh patented nichrome in 1906, making it the oldest documented resistance heating alloy.","Hot-wire foam cutters use nichrome wire.","Sculptors use nichrome wire inside clay to help soft pieces hold their shape in the kiln."],"where":[],"whereNote":null,"sources":[{"title":"Nichrome","url":"https://en.wikipedia.org/wiki/Nichrome"},{"title":"Heating element","url":"https://en.wikipedia.org/wiki/Heating_element"},{"title":"Nichrome Wire (FANMETAL)","url":"https://www.fanmetalloy.com/nickel-and-alloys/nickel-alloy/nichrome-wire.html"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"nickel","name":"Nickel","kind":"material","category":"metals","title":"How nickel is made","url":"https://assemblyline.org/make/nickel","stations":5,"upstream":5,"downstream":58,"depth":2,"dek":"The purest nickel is made by turning it into a gas with carbon monoxide and then letting it plate itself onto pellets.","answer":"Nickel comes from sulfide or laterite ores. Sulfide ore is crushed, floated and smelted to a matte, which is refined by leaching and plating out nickel electrically, or by the Mond process. In that process nickel is turned into a gas with carbon monoxide and then decomposed to give metal over 99.99 percent pure.","aka":["refined nickel","electrolytic nickel"],"inputs":["nickel-ore","sulfuric-acid"],"uses":["thermometer","lithium-ion-cell","aa-battery","stainless-steel","neodymium-magnet","safety-pin","needle","faucet","coin","sunglasses","jet-engine","turbine-blade","trumpet","toaster","flute","key","wrench","spark-plug","eyeglass-frame","usb-cable","vinyl-record","compact-disc","nichrome"],"grounds":["nickel-ore","sulfur","air","water"],"upstreamSlugs":["nickel-ore","sulfuric-acid","sulfur","air","water"],"downstreamSlugs":["thermometer","lithium-ion-cell","aa-battery","stainless-steel","neodymium-magnet","safety-pin","needle","faucet","coin","sunglasses","jet-engine","turbine-blade","trumpet","toaster","flute","key","wrench","spark-plug","eyeglass-frame","usb-cable","vinyl-record","compact-disc","nichrome","ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","syringe","washing-machine","electric-kettle","wristwatch","kitchen-knife","fork","razor-blade","elevator","fountain-pen","thermos","water-bottle","pressure-cooker","blender","dishwasher","ice-skates","golf-club","asthma-inhaler","subway-train","headphones","wind-turbine","loudspeaker","microphone","airplane","electric-car","skyscraper"],"steps":[{"name":"Crush the nickel ore","process":"crush","text":"Nickel ores are either oxides, such as laterite, or sulfides, mainly pentlandite. About 60 percent of known resources are in laterites and 40 percent in sulfide deposits. Sulfide rock is crushed and ground.","inputs":["nickel-ore"]},{"name":"Float the sulfides","process":"separate","text":"Most sulfide deposits are first concentrated by froth flotation, which lifts the nickel minerals away from waste rock.","inputs":[]},{"name":"Smelt it to a matte","process":"melt","text":"Furnaces roast and smelt the concentrate into a nickel matte. A conventional route like this produces metal that is at least 75 percent nickel, good enough for many stainless steel uses without further refining.","inputs":[]},{"name":"Leach and plate it","process":"electrolyze","text":"In one refining route the matte is leached into a nickel salt solution, and the nickel is electroplated from solution onto cathodes as electrolytic nickel.","inputs":["sulfuric-acid"]},{"name":"Turn it to a gas and back","process":"refine","text":"In the Mond process, nickel is treated with carbon monoxide and forms nickel carbonyl gas. Heating the gas makes it fall apart, depositing pure nickel onto pellets that are constantly stirred.","inputs":[],"spec":"over 99.99% pure"}],"facts":["About 68 percent of the nickel produced goes into stainless steel.","The five-cent coins that Canada struck from 1922 to 1981 were 99.9 percent nickel, so they were magnetic.","Nickel carbonyl, which makes the Mond process work, is a volatile and highly toxic liquid at room temperature."],"where":[{"place":"Indonesia","share":"2,600,000 tonnes mined"},{"place":"Philippines","share":"270,000 tonnes mined"},{"place":"Russia","share":"200,000 tonnes mined"},{"place":"Canada","share":"140,000 tonnes mined"},{"place":"New Caledonia","share":"140,000 tonnes mined"}],"whereNote":"2025, nickel mined, out of about 3.9 million tonnes worldwide.","sources":[{"title":"Nickel","url":"https://en.wikipedia.org/wiki/Nickel"},{"title":"Froth flotation","url":"https://en.wikipedia.org/wiki/Froth_flotation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"nickel-ore","name":"Nickel ore","kind":"raw","category":"ground","title":"How nickel ore is mined","url":"https://assemblyline.org/make/nickel-ore","stations":5,"upstream":0,"downstream":60,"depth":0,"dek":"Nickel mining splits in two: earth-moving through soft tropical laterite, or tunneling after hard sulfide rock.","answer":"Nickel ore comes in two kinds, and each gets its own mine. Laterite is soft, claylike and near the surface, so shovels and draglines load it into trucks like dirt. Sulfide ore is hard rock mined mostly underground, then ground and floated into a concentrate of 10 to 20% nickel. Either way, ore is generally worth mining above about 1.3% nickel.","aka":["pentlandite","laterite"],"inputs":[],"uses":["nickel","iridium"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["nickel","iridium","thermometer","lithium-ion-cell","aa-battery","stainless-steel","neodymium-magnet","safety-pin","needle","faucet","coin","sunglasses","jet-engine","turbine-blade","trumpet","toaster","flute","key","wrench","spark-plug","eyeglass-frame","usb-cable","vinyl-record","compact-disc","nichrome","ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","syringe","washing-machine","electric-kettle","wristwatch","kitchen-knife","fork","razor-blade","elevator","fountain-pen","thermos","water-bottle","pressure-cooker","blender","dishwasher","ice-skates","golf-club","asthma-inhaler","subway-train","headphones","wind-turbine","loudspeaker","microphone","airplane","electric-car","skyscraper"],"steps":[{"name":"Scrape the laterite","process":"mine","text":"Long weathering of peridotite leaves nickel concentrated in soft strata near the surface. Big shovels, draglines or front-end loaders dig those layers, throw aside boulders and waste, and load trucks at the face.","inputs":[]},{"name":"Screen the soft ore","process":"separate","text":"Laterite is crushed and screened, and wet plants add hydrocyclones, stripping out waste until the nickel content has typically doubled. The richer feed then goes to a smelter.","inputs":[]},{"name":"Tunnel the sulfide rock","process":"mine","text":"Sulfide deposits are usually mined underground in much the same way as copper, though some began as open pits. The ore mixes pentlandite, the main nickel mineral, with pyrrhotite and copper minerals.","inputs":[]},{"name":"Crush and ball-mill","process":"crush","text":"One common route starts with a gyratory crusher and then a ball mill fed wet, which frees the sulfide grains from the rock.","inputs":[]},{"name":"Float the pentlandite","process":"separate","text":"Air bubbles carry water-repelling pentlandite to the surface. A flotation stage splits the feed into nickel concentrate at 10 to 20% nickel, a separate copper concentrate, and barren waste under 0.3% nickel.","inputs":[],"spec":"10 to 20% nickel"}],"facts":["Land-based nickel resources averaging 1% nickel or more are about 60% in laterites and 40% in sulfide deposits.","Canada struck its five-cent coins from 99.9% nickel from 1922 to 1981, which is why those coins stick to a magnet.","Ore bound for the smelter at Le Nickel in New Caledonia held 9% nickel in 1900 and holds only 1 to 3% today."],"where":[{"place":"Indonesia","share":"2,600,000 t"},{"place":"Philippines","share":"270,000 t"},{"place":"Russia","share":"200,000 t"},{"place":"Canada","share":"140,000 t"},{"place":"New Caledonia","share":"140,000 t"}],"whereNote":"Nickel mined in 2025 (estimate), out of about 3.9 million tonnes worldwide.","sources":[{"title":"Nickel processing","url":"https://www.britannica.com/technology/nickel-processing"},{"title":"Nickel extraction","url":"https://en.wikipedia.org/wiki/Nickel_extraction"},{"title":"Nickel","url":"https://en.wikipedia.org/wiki/Nickel"},{"title":"Pentlandite","url":"https://en.wikipedia.org/wiki/Pentlandite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"nitric-acid","name":"Nitric acid","kind":"material","category":"chemicals","title":"How nitric acid is made","url":"https://assemblyline.org/make/nitric-acid","stations":5,"upstream":4,"downstream":179,"depth":2,"dek":"Nitric acid is made by burning ammonia on a screen of platinum wire, the way it has been since 1902.","answer":"Nitric acid is made from ammonia. Ammonia gas is mixed with air and burned over a fine mesh of platinum and rhodium, forming nitric oxide. The gas is cooled so it reacts further with oxygen, then it is absorbed in water to make dilute nitric acid, which is distilled to a higher strength.","aka":["aqua fortis","HNO3","Ostwald process"],"inputs":["ammonia","air","water"],"uses":["nail-polish","acetaminophen","fertilizer","nylon","polyurethane","platinum","iridium"],"grounds":["air","water","natural-gas"],"upstreamSlugs":["ammonia","air","water","natural-gas"],"downstreamSlugs":["nail-polish","acetaminophen","fertilizer","nylon","polyurethane","platinum","iridium","toothbrush","mascara","drone","tire","airbag","guitar","violin","basketball","bike-helmet","velcro","dishwasher","office-chair","roller-skates","tennis-racket","volleyball","kite","action-figure","fashion-doll","ukulele","drumstick","eyeshadow","dental-floss","aluminum-window-frame","underwear","leggings","swimsuit","down-jacket","raincoat","handbag","backpack","hiking-boots","flag","electric-toothbrush","socks","carpet","zipper","rope","adhesive-bandage","pacemaker","adhesive","refrigerator","car","skateboard","surfboard","golf-ball","soccer-ball","hardwood-floor","water-heater","sofa","bowling-ball","wheelchair","sneaker","mattress","hard-drive","electric-car","bicycle","motorcycle","suitcase","jeans","credit-card","duct-tape","led-bulb","ev-battery","pencil","nail","insulation","popcorn","windshield","piano","drum-kit","tennis-ball","baseball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","pencil-eraser","clear-tape","staple","ski","snowboard","ice-skates","golf-club","fishing-rod","cricket-bat","dartboard","chess-set","board-game","jigsaw-puzzle","cello","globe","snow-globe","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","brake-pad","sailboat","dress-shirt","suit","wallet","flip-flops","high-heels","smartwatch","wireless-earbuds","loudspeaker","microphone","camera-lens","e-reader","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","leather-shoe","baseball-cap","diaper","digital-camera","shipping-container","ceiling-fan","treadmill","fireworks","plastic-wrap","trading-cards","cake-mix","soda","energy-drink","hair-dye","tampon","soap","toothpaste","deodorant","detergent","plastic-bag","nitrile-glove","washing-machine","vacuum-cleaner","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","blender","pillow","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","game-console","wifi-router","remote-control","facial-tissue","aa-battery","candy-cane","syringe"],"steps":[{"name":"Mix ammonia with air","process":"mix","text":"Ammonia gas is vaporized and blended with filtered air in carefully controlled proportions. That blend is the fuel for the entire process.","inputs":["ammonia","air"]},{"name":"Burn it over platinum gauze","process":"react","text":"The mixture flows through several layers of fine platinum and rhodium wire mesh and burns in a fraction of a second, giving nitric oxide and steam. The burn gives off plenty of heat, so once it has started it keeps itself going.","inputs":[]},{"name":"Cool and oxidize the gas","process":"chill","text":"Heat exchangers cool the gas, recovering the heat as steam. As it cools, nitric oxide picks up more oxygen from the air and turns into brown nitrogen dioxide.","inputs":[]},{"name":"Absorb it in water","process":"react","text":"The brown gas rises through a column of plates while water trickles down. It dissolves into dilute nitric acid, and some of the gas that is left over turns back into nitric oxide and goes round again.","inputs":["water"]},{"name":"Concentrate by distilling","process":"refine","text":"The weak acid is distilled to the strength a buyer needs. Most of it goes straight on to make fertilizer.","inputs":[]}],"facts":["The platinum catalyst slowly degrades into a cauliflower-like texture in the furnace, and plants swap the gauze out regularly.","Wilhelm Ostwald patented the method in 1902, but it became economical only after the Haber-Bosch process began supplying ammonia.","Germany kept making nitric acid during the First World War, when the Allied blockade cut off imports of Chilean nitrate, because it could make ammonia from air."],"where":[],"whereNote":null,"sources":[{"title":"Ostwald process","url":"https://en.wikipedia.org/wiki/Ostwald_process"},{"title":"Nitric acid","url":"https://en.wikipedia.org/wiki/Nitric_acid"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"nitrile-glove","name":"Nitrile glove","kind":"product","category":"plastics","title":"How nitrile gloves are made","url":"https://assemblyline.org/make/nitrile-glove","stations":8,"upstream":57,"downstream":0,"depth":10,"dek":"Nitrile gloves are made by dipping hand-shaped ceramic formers into liquid synthetic rubber.","answer":"A clean hand-shaped mold is preheated to about 58 °C, dipped in calcium nitrate, dried and dipped into compounded nitrile emulsion, where a gelled glove forms. A bead is rolled at the cuff, and water soaks out soluble materials. Ovens dry it, then higher heat lets sulfur crosslink the rubber. It is stripped and treated with chlorinated water to reduce tack.","aka":["exam glove","disposable glove","nitrile butadiene rubber glove"],"inputs":["water","synthetic-rubber","sulfur","chlorine","cardboard-box"],"uses":[],"grounds":["water","sulfur","rock-salt","crude-oil","natural-gas","air","coal","timber","soybeans","rapeseed","clay","titanium-ore","iron-ore","corn","sugarcane","limestone","sugar-beet"],"upstreamSlugs":["water","synthetic-rubber","sulfur","chlorine","cardboard-box","naphtha","benzene","ethylene","styrene","rock-salt","sulfuric-acid","cardboard","ink","adhesive","crude-oil","hydrogen","toluene","natural-gas","air","wood-pulp","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","coal","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","titanium-ore","coke","iron-ore","corn","sugarcane","yeast","propylene","ammonia","methanol","acetone","nitric-acid","limestone","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Clean and preheat molds","process":"wash","text":"Hand-shaped molds are washed clean and warmed to about 55 to 60 °C for the first dip.","inputs":["water"],"spec":"55-60 °C"},{"name":"Dip in coagulant","process":"coat","text":"The mold dips into a water solution of calcium nitrate. It dries and reheats to about 70 °C, leaving a coating that will make the rubber gel on contact.","inputs":[]},{"name":"Dip in nitrile emulsion","process":"coat","text":"Next comes a bath of compounded nitrile emulsion, where a gelled glove forms on the mold. Faster entry and exit give a more even thickness from fingertip to cuff.","inputs":["synthetic-rubber","sulfur"]},{"name":"Bead the cuff","process":"mold","text":"A bead is rolled at the top of the cuff while the film is still gel.","inputs":[]},{"name":"Soak out solubles","process":"wash","text":"The mold and gel soak in water that removes water-soluble material.","inputs":["water"]},{"name":"Dry and cure","process":"heat-treat","text":"Ovens dry the gel at about 80 °C to just below 100 °C. A higher temperature then starts the sulfur reaction that crosslinks the polymer.","inputs":[]},{"name":"Strip and treat","process":"wash","text":"The glove comes off the mold, and its surfaces are treated with chlorinated water to reduce tack.","inputs":["chlorine"]},{"name":"Dry and pack","process":"package","text":"The gloves are dried and readied for packaging.","inputs":["cardboard-box"]}],"facts":["Medical gloves are made from latex, nitrile rubber, polyvinyl chloride and neoprene, either powdered with corn starch or unpowdered.","William Halsted asked the Goodyear Rubber Company for thin rubber gloves for his future wife, Caroline Hampton, after she developed a skin reaction in 1889 or 1890, and he introduced sterilized gloves at Johns Hopkins in 1894."],"where":[],"whereNote":null,"sources":[{"title":"US8250672B2: Exterior-coated nitrile rubber article having natural rubber characteristics","url":"https://patents.google.com/patent/US8250672"},{"title":"Nitrile rubber","url":"https://en.wikipedia.org/wiki/Nitrile_rubber"},{"title":"Medical glove","url":"https://en.wikipedia.org/wiki/Medical_glove"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"nitrogen","name":"Nitrogen gas","kind":"material","category":"chemicals","title":"How nitrogen gas is made","url":"https://assemblyline.org/make/nitrogen","stations":5,"upstream":1,"downstream":46,"depth":1,"dek":"Industrial nitrogen is simply air, chilled until it liquefies and then boiled apart again.","answer":"Nitrogen gas is separated from air by cooling air until it turns to liquid, then distilling it. Nitrogen boils at a lower temperature than oxygen, so it rises as a vapor out of the top of a tall column while oxygen collects at the bottom. Small sites often use membranes or pressure-swing beds instead.","aka":["N2","liquid nitrogen","air separation"],"inputs":["air"],"uses":["polysilicon","memory-chip","window-glass","light-bulb","potato-chips","beef-jerky","office-chair","fire-extinguisher"],"grounds":["air"],"upstreamSlugs":["air"],"downstreamSlugs":["polysilicon","memory-chip","window-glass","light-bulb","potato-chips","beef-jerky","office-chair","fire-extinguisher","silicon-wafer","smartphone","laptop","solid-state-drive","smartwatch","digital-camera","game-console","wifi-router","graphics-card","mirror","skyscraper","windshield","double-glazed-window","microchip","camera-sensor","solar-cell","inkjet-printer","car","electric-car","aluminum-window-frame","hearing-aid","pacemaker","thermometer","credit-card","television","computer-keyboard","computer-mouse","drone","satellite","airbag","rocket","wireless-earbuds","phone-charger","usb-cable","e-reader","remote-control","electric-toothbrush","solar-panel"],"steps":[{"name":"Suck in and compress air","process":"press","text":"Big compressors draw in outside air and squeeze it, and the compression is the energy source for the whole plant. The water that condenses on the way is drained off.","inputs":["air"]},{"name":"Strip out water and CO2","process":"wash","text":"The air passes through beds of molecular sieve that trap remaining moisture and carbon dioxide. Left in, these would freeze solid and plug the frigid equipment.","inputs":[]},{"name":"Chill it near liquefaction","process":"chill","text":"In a plate-fin heat exchanger the incoming air is cooled against the cold product streams leaving the plant. Part of the air condenses to a liquid with extra oxygen in it.","inputs":[]},{"name":"Boil it apart in a column","process":"refine","text":"Nitrogen boils at a lower temperature than oxygen, so it rises as vapor through the column while oxygen-rich liquid trickles down. The nitrogen at the top can reach better than one part per million of impurity.","inputs":[]},{"name":"Store as liquid or pipe as gas","process":"fill","text":"Nitrogen is shipped as a liquid in insulated tankers or piped to nearby factories as a gas. The cold equipment sits inside an insulated enclosure called a cold box.","inputs":[]}],"facts":["Nitrogen makes up about 78% of Earth's atmosphere, which makes it the most common chemical species in the air.","Carl von Linde developed air liquefaction in 1895, and it was first used in industry in 1902.","Pressure-swing and membrane systems can pull one gas from ordinary air, but the highest-purity nitrogen and oxygen still require cryogenic distillation."],"where":[],"whereNote":null,"sources":[{"title":"Air separation","url":"https://en.wikipedia.org/wiki/Air_separation"},{"title":"Nitrogen","url":"https://en.wikipedia.org/wiki/Nitrogen"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"non-alcoholic-beer","name":"Non-alcoholic beer","kind":"product","category":"drink","title":"How non-alcoholic beer is made","url":"https://assemblyline.org/make/non-alcoholic-beer","stations":6,"upstream":58,"downstream":0,"depth":9,"dek":"Most non-alcoholic beer starts as ordinary beer, and the alcohol is then pulled out of it.","answer":"Typical non-alcoholic beer is brewed as normal beer, then run through an alcohol-removing step just before finishing. Vacuum evaporation boils off the alcohol at low temperature. Reverse osmosis filters it out through a membrane. The cheapest method is simply diluting with water. The result must contain under 0.5 percent alcohol by volume in many places.","aka":["alcohol-free beer","near beer","zero beer"],"inputs":["barley","hops","water","malted-barley","yeast","carbon-dioxide","glass-bottle","aluminum-can"],"uses":[],"grounds":["barley","hops","water","natural-gas","corn","limestone","silica-sand","sugarcane","sugar-beet","rock-salt","trona","crude-oil","coal","air","bauxite","soybeans","rapeseed","clay","titanium-ore","iron-ore","sulfur"],"upstreamSlugs":["barley","hops","water","malted-barley","yeast","carbon-dioxide","glass-bottle","aluminum-can","molasses","natural-gas","corn","limestone","silica-sand","soda-ash","polyethylene","aluminum","ink","epoxy","sugarcane","sugar-beet","rock-salt","ammonia","lime","trona","ethylene","crude-oil","coal","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","phenol","propylene","acetone","chlorine","caustic-soda","air","naphtha","bauxite","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","coke","oxygen","sulfuric-acid","iron-ore","sulfur","benzene","hydrogen","methanol","toluene"],"downstreamSlugs":[],"steps":[{"name":"Brew the wort","process":"cook","text":"Malted grain is mashed in hot water, and the wort is boiled for roughly one to two hours with hops and other grains that add flavor, color and aroma.","inputs":["barley","hops","water","malted-barley"]},{"name":"Ferment as usual","process":"ferment","text":"The cooled wort is saturated with air and yeast is added in the fermentation tank. This takes around ten days.","inputs":["yeast"]},{"name":"Condition the beer","process":"dry","text":"The fresh beer sits in a conditioning tank to age. Rushing this gives a green-apple off flavor called acetaldehyde.","inputs":[]},{"name":"Remove the alcohol","process":"separate","text":"Older plants heat the beer to boil alcohol off. Most modern breweries use vacuum evaporation to lower the boiling point, or push the beer through a membrane by reverse osmosis so no heating is needed.","inputs":[]},{"name":"Filter and carbonate","process":"separate","text":"The beer gets a last filtration, is carbonated and moves to a storage tank for bottling or kegging.","inputs":["carbon-dioxide"]},{"name":"Bottle or can","process":"fill","text":"The finished beer is filled into bottles, cans or kegs.","inputs":["glass-bottle","aluminum-can"]}],"facts":["During Prohibition the Volstead Act limited drinks to 0.5 percent alcohol, and the weak brews were called near beer.","Dealcoholized beer is over 0.05 but under 0.5 percent alcohol, while alcohol-free is lower than that.","A newer process called dual-stage vacuum filtration captures flavor first, then removes the alcohol, then puts the flavor back."],"where":[],"whereNote":null,"sources":[{"title":"Non-alcoholic beer","url":"https://en.wikipedia.org/wiki/Non-alcoholic_beer"},{"title":"Brewing","url":"https://en.wikipedia.org/wiki/Brewing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"nonstick-pan","name":"Nonstick pan","kind":"product","category":"hardware","title":"How nonstick pans are made","url":"https://assemblyline.org/make/nonstick-pan","stations":7,"upstream":23,"downstream":0,"depth":5,"dek":"Nonstick pans began with a French engineer who coated his fishing tackle and then his wife's pans.","answer":"Aluminum pan blanks are sprayed clean with alkaline cleaner and hot water, then blasted with hard iron grit so a coating can grip. After another wash and an acid clean, PTFE is sprayed, brushed or flowed on and air dried. Baking for about five minutes sinters it. Some aluminum pans are pressed from discs already coated.","aka":["Teflon pan","nonstick skillet","frying pan"],"inputs":["aluminum","water","ptfe","plastic"],"uses":[],"grounds":["water","crude-oil","coal","fluorspar","natural-gas","bauxite","sulfur","air","rock-salt","limestone"],"upstreamSlugs":["aluminum","water","ptfe","plastic","crude-oil","coal","petroleum-coke","alumina","sulfuric-acid","fluorspar","natural-gas","chlorine","naphtha","ethylene","propylene","bauxite","caustic-soda","lime","sulfur","air","rock-salt","hydrogen","limestone"],"downstreamSlugs":[],"steps":[{"name":"Press the shell","process":"stamp","text":"A press forms the shell from an aluminum disc. Softer aluminum can even be shaped after coating, while harder metals like steel are coated once they are formed.","inputs":["aluminum"]},{"name":"Wash the blanks","process":"wash","text":"High-pressure hoses spray a mild alkaline cleaner and then hot water to remove oil and dirt. A hot rinse and air drying prevent any marks.","inputs":["water"]},{"name":"Blast with iron grit","process":"grind","text":"A centrifuge throws hard, sharp iron grit evenly across the aluminum, roughening its surface. An air blast then clears away loose grit.","inputs":[]},{"name":"Clean with acid","process":"wash","text":"The blanks are washed and rinsed again, and acids restore the bright metal. Etching leaves more surface for the coating to hold.","inputs":[]},{"name":"Apply the coating","process":"coat","text":"PTFE is sprayed, brushed or flowed across the dry metal, then air dried. Layers build up from a primer that grips both metal and topcoat.","inputs":["ptfe"]},{"name":"Sinter in the oven","process":"heat-treat","text":"An oven bakes the coating for about five minutes at a heat that fuses it into a slick film.","inputs":[],"spec":"about five minutes"},{"name":"Rivet on the handle","process":"assemble","text":"A handle is fixed on after the coating is done, and the pan is packed.","inputs":["plastic"]}],"facts":["PTFE was discovered by accident in 1938 by Roy Plunkett.","Tefal was formed in 1956 after French engineer Marc Grégoire coated his wife's pans with the material he used on fishing tackle.","Past about 260 °C, PTFE begins to break down and give off fumes that can be lethal to pet birds."],"where":[],"whereNote":null,"sources":[{"title":"Explain that Stuff: How nonstick pans are made","url":"https://explainthatstuff.com/nonstickpans.html"},{"title":"Judge: How is the coating applied to the pan?","url":"https://judge.co.uk/knowledge-base/how-is-the-coating-applied-to-the-pan"},{"title":"Non-stick surface","url":"https://en.wikipedia.org/wiki/Non-stick_surface"},{"title":"Polytetrafluoroethylene","url":"https://en.wikipedia.org/wiki/Polytetrafluoroethylene"},{"title":"Deep drawing","url":"https://en.wikipedia.org/wiki/Deep_drawing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"nori","name":"Nori","kind":"product","category":"food","title":"How nori is made","url":"https://assemblyline.org/make/nori","stations":6,"upstream":1,"downstream":0,"depth":1,"dek":"Nori sheets are made much like paper: seaweed is shredded, spread on screens and dried.","answer":"Nori is grown on nets suspended at the sea surface. Farmers harvest the red seaweed by machine every ten days or so, chop it into a slurry and spread the slurry onto screens in a process much like making paper. The thin sheets are dried on racks, then often toasted. A desiccant keeps them crisp in the pack.","aka":["laver","sushi seaweed","dried seaweed sheets"],"inputs":["seaweed"],"uses":[],"grounds":["seaweed"],"upstreamSlugs":["seaweed"],"downstreamSlugs":[],"steps":[{"name":"Seed the nets","process":"grow","text":"Nori farmers seed nets with young Pyropia and suspend them at the sea surface, working from boats. About 45 days pass before the first harvest.","inputs":[],"spec":"about 45 days to first harvest"},{"name":"Harvest by machine","process":"harvest","text":"Mechanical harvesters cut the blades from the nets. A single seeding can be harvested repeatedly, about every ten days.","inputs":["seaweed"],"spec":"about every 10 days"},{"name":"Chop to a slurry","process":"crush","text":"The seaweed is washed and shredded into small pieces in water.","inputs":[]},{"name":"Spread onto screens","process":"cast","text":"Automated machines pour the seaweed slurry onto flat screens in thin layers, a mechanical copy of the hand method, which was borrowed from Japanese papermaking around 1750.","inputs":[]},{"name":"Dry on racks","process":"dry","text":"Racks of screens carry the wet sheets through drying. What comes off is a paper-thin, black, dried sheet.","inputs":[]},{"name":"Toast and pack","process":"bake","text":"Sheets are often toasted and sometimes seasoned with soy sauce, sugar and other flavors. Because nori soaks up moisture from the air and degrades, packs include a desiccant.","inputs":[]}],"facts":["Japan's nori industry was rescued after World War II by the work of British phycologist Kathleen Drew-Baker, who had unraveled the seaweed's life cycle.","Japan devotes more than 600 square kilometers of coastal water to producing 350,000 tonnes of nori.","Nori was used as currency in Japan and counted as a form of taxation in the Taiho Code of 701."],"where":[],"whereNote":null,"sources":[{"title":"Nori","url":"https://en.wikipedia.org/wiki/Nori"},{"title":"Pyropia","url":"https://en.wikipedia.org/wiki/Pyropia"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"nylon","name":"Nylon","kind":"material","category":"plastics","title":"How nylon is made","url":"https://assemblyline.org/make/nylon","stations":6,"upstream":11,"downstream":43,"depth":5,"dek":"Nylon was invented at DuPont and announced in 1938, after an eleven-year research program.","answer":"Nylon 66 is made by combining adipic acid with hexamethylenediamine into a salt, then heating the salt in a pressure vessel so water leaves and long chains form. The molten polymer is cast into ribbon and chopped into chips, or melted again and spun through tiny holes into filaments that are stretched to align the chains.","aka":["polyamide","nylon 66","PA66"],"inputs":["benzene","nitric-acid","ammonia"],"uses":["toothbrush","mascara","drone","tire","airbag","guitar","violin","basketball","bike-helmet","velcro","dishwasher","office-chair","roller-skates","tennis-racket","volleyball","kite","action-figure","fashion-doll","ukulele","drumstick","eyeshadow","dental-floss","aluminum-window-frame","underwear","leggings","swimsuit","down-jacket","raincoat","handbag","backpack","hiking-boots","flag","electric-toothbrush","socks","carpet","zipper","rope"],"grounds":["air","water","natural-gas","crude-oil","coal"],"upstreamSlugs":["benzene","nitric-acid","ammonia","naphtha","hydrogen","toluene","air","water","natural-gas","crude-oil","coal"],"downstreamSlugs":["toothbrush","mascara","drone","tire","airbag","guitar","violin","basketball","bike-helmet","velcro","dishwasher","office-chair","roller-skates","tennis-racket","volleyball","kite","action-figure","fashion-doll","ukulele","drumstick","eyeshadow","dental-floss","aluminum-window-frame","underwear","leggings","swimsuit","down-jacket","raincoat","handbag","backpack","hiking-boots","flag","electric-toothbrush","socks","carpet","zipper","rope","car","electric-car","bicycle","motorcycle","suitcase","jeans"],"steps":[{"name":"Make adipic acid","process":"react","text":"Benzene from refined naphtha is converted through intermediate compounds, and the last step is oxidation with nitric acid. The product is a white crystalline acid.","inputs":["benzene","nitric-acid"]},{"name":"Make the diamine","process":"react","text":"Adipic acid is processed with ammonia into the other half of the nylon, hexamethylenediamine. Both halves have six carbon atoms, which gives nylon 66 its name.","inputs":["ammonia"]},{"name":"Marry them into a salt","process":"mix","text":"The acid and the diamine are mixed in water in equal amounts, which forms nylon salt. A salt makes the balance exact, and the chains will only grow long if the halves match.","inputs":[]},{"name":"Heat it into long chains","process":"react","text":"The salt solution is concentrated and heated in a sealed vessel. Water boils off as the molecules join, and the thickened melt becomes polyamide.","inputs":[]},{"name":"Spin it into filaments","process":"spin","text":"The melt is forced through a plate pierced with fine holes, and the strands harden in a flow of cool air. Dozens of them are gathered into a single yarn.","inputs":[]},{"name":"Stretch to line up the chains","process":"draw","text":"The yarn is stretched to several times its length, which aligns the molecules along the fiber and makes it strong. It is then wound onto bobbins for weavers and knitters.","inputs":[]}],"facts":["Wallace Hume Carothers first made nylon 66 on February 28, 1935, at DuPont's Experimental Station.","When nylon stockings first went on public sale in Wilmington, Delaware, in October 1939, all 4,000 pairs sold within three hours.","Paul Schlack at IG Farben developed nylon 6, based on caprolactam, in January 1938."],"where":[],"whereNote":null,"sources":[{"title":"Nylon","url":"https://en.wikipedia.org/wiki/Nylon"},{"title":"Kevlar","url":"https://en.wikipedia.org/wiki/Kevlar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wine-barrel","name":"Oak wine barrel","kind":"product","category":"wood-paper","title":"How oak wine barrels are made","url":"https://assemblyline.org/make/wine-barrel","stations":7,"upstream":25,"downstream":6,"depth":5,"dek":"A wine barrel holds its wine with no glue and no fixings, only tight-fitting staves squeezed by hoops.","answer":"Long oak staves are seasoned outdoors for two or three years, then shaped so their edges fit tightly. A cooper raises them inside metal hoops, softens them with steam or heat, and bends them together. The barrel is toasted over a fire, fitted with its round heads, sanded, and hooped again.","aka":["oak barrel","wine cask","barrique"],"inputs":["timber","steel"],"uses":["wine","bourbon","scotch","cognac","port-wine"],"grounds":["timber","iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","coal","quartz","crude-oil","sulfur"],"upstreamSlugs":["timber","steel","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","coal","quartz","charcoal","crude-oil","sulfur"],"downstreamSlugs":["wine","bourbon","scotch","cognac","port-wine","champagne"],"steps":[{"name":"Season the staves outdoors","process":"dry","text":"Long planks of oak called staves are stacked outside and left to weather. The rain and sun draw out harsh compounds that would otherwise make wine bitter.","inputs":["timber"],"spec":"two or three years"},{"name":"Shape each stave","process":"machine","text":"Every stave is cut to a tapered shape with beveled edges. The fit matters, because the finished barrel is watertight without glue or fixings.","inputs":[]},{"name":"Raise them in hoops","process":"assemble","text":"The cooper stands the staves upright inside a metal hoop to form a cage with a wide middle and open ends.","inputs":[]},{"name":"Steam and bend","process":"cook","text":"Heat or steam softens the lignin in the wood, so the staves can be pulled together at one end with a cable and extra hoops without cracking.","inputs":[]},{"name":"Toast over a fire","process":"bake","text":"The inside of the barrel is toasted over a low flame. The heat caramelizes sugars in the wood and sets the flavors the barrel will pass on to wine. A wine barrel is toasted for about 35 minutes.","inputs":[],"spec":"about 35 minutes"},{"name":"Cut and fit the heads","process":"machine","text":"Round heads are cut from boards, then wedged into grooves cut near each end of the staves.","inputs":[]},{"name":"Sand and rehoop","process":"grind","text":"Work hoops are knocked off, the outside is sanded, and the final hoops are driven into position.","inputs":["steel"]}],"facts":["A wall painting in an Egyptian tomb from 2600 BC shows a tub made of staves bound with hoops.","A whiskey barrel is charred for about 45 seconds on a high fire, while a wine barrel is toasted at low heat for about 35 minutes.","Pliny the Elder reported that coopering began with the Gauls in Alpine villages."],"where":[],"whereNote":null,"sources":[{"title":"How oak barrels for wine are made: an illustrated guide","url":"https://wineanorak.com/howoakbarrelsaremade.htm"},{"title":"Cooperage","url":"https://en.wikipedia.org/wiki/Cooperage"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"oat-milk","name":"Oat milk","kind":"product","category":"food","title":"How oat milk is made","url":"https://assemblyline.org/make/oat-milk","stations":8,"upstream":13,"downstream":0,"depth":4,"dek":"Oat milk only works because enzymes chop the starch in oats before it can turn the drink to glue.","answer":"Oats are milled, stirred into warm water and ground to a slurry. Enzymes and heat break the starch into smaller sugars and make a thick oat base. A centrifuge or filter removes the solids. Vitamins, oil and salt are added, then the liquid is homogenized and heat-treated to last.","aka":["oat drink","oat beverage"],"inputs":["oats","water","vegetable-oil","table-salt"],"uses":[],"grounds":["oats","water","soybeans","rapeseed","clay","rock-salt","seawater","crude-oil","natural-gas"],"upstreamSlugs":["oats","water","vegetable-oil","table-salt","soybeans","rapeseed","hexane","clay","rock-salt","seawater","crude-oil","hydrogen","natural-gas"],"downstreamSlugs":[],"steps":[{"name":"Mill the oats","process":"crush","text":"Measured oats are milled to break the grains open so water can reach the inside.","inputs":["oats"]},{"name":"Grind into warm slurry","process":"mix","text":"Warm water joins the oat meal in a grinder, which turns it into a thin slurry.","inputs":["water"]},{"name":"Dose with enzymes","process":"react","text":"Enzymes and heat are added to the slurry. Oats are 50 to 60 percent starch, which would gel and clog the process. Amylase enzymes chop the starch into smaller sugars before that happens, and the slurry thins into an oat base.","inputs":[],"spec":"oats are 50 to 60% starch"},{"name":"Spin out the solids","process":"separate","text":"Decanting, filters and centrifuges pull the liquid away from the leftover fiber.","inputs":[]},{"name":"Fortify and season","process":"mix","text":"Oil, salt, sweetener and flavorings may be stirred in. Oat milk is naturally low in calcium, iron and vitamin A compared with cow's milk, so makers add vitamins and minerals.","inputs":["vegetable-oil","table-salt"]},{"name":"Homogenize it smooth","process":"mix","text":"The liquid is forced through a homogenizer to shrink and even out the particle sizes. Stabilizers may also be used for steadiness.","inputs":[]},{"name":"Heat-treat for shelf life","process":"pasteurize","text":"Pasteurization, or ultra-high temperature treatment for shelf-stable cartons, kills microbes. Without the starch-cutting step earlier the starch would have gelled in this heat.","inputs":[]},{"name":"Fill the cartons","process":"fill","text":"The finished drink is filled into cartons or bottles and sealed.","inputs":[]}],"facts":["Oat milk was developed in the 1990s by Swedish scientists, and a first patent application was filed in 1994.","In the United States, oat milk sales jumped 303 percent in one year, from 2019 to 2020."],"where":[],"whereNote":null,"sources":[{"title":"Oat milk","url":"https://en.wikipedia.org/wiki/Oat_milk"},{"title":"Soy milk","url":"https://en.wikipedia.org/wiki/Soy_milk"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"oats","name":"Oats","kind":"raw","category":"farm","title":"How oats are grown and harvested","url":"https://assemblyline.org/make/oats","stations":3,"upstream":0,"downstream":3,"depth":0,"dek":"Oats thrive in cool, wet summers where wheat and corn struggle, and they must be dried below 13% moisture to keep.","answer":"Oats are an annual grass sown in spring in cooler regions and in autumn in warmer ones. They tolerate poor soil and wet summers better than other cereals. A combine harvests them either directly or after the crop has dried in windrows, because the grain must be at 13% moisture or below to store safely.","aka":["oat farming","oat crop","oat harvest","grain oats"],"inputs":[],"uses":["oat-milk","oatmeal"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["oat-milk","oatmeal","granola-bar"],"steps":[{"name":"Sow in cool, damp ground","process":"grow","text":"Oats suit regions with cool, wet summers, such as Northwest Europe. They handle low-nutrient soil better than wheat or maize, but sustained cold below −7 °C harms them. In the US Midwest they are sown in spring and in the South in autumn.","inputs":[]},{"name":"Rotate with other crops","process":"grow","text":"In the Corn Belt oats follow corn, soybeans and forage crops in a rotation. Farmers traditionally grew them with red clover and alfalfa, which fixed nitrogen and fed livestock.","inputs":[]},{"name":"Combine and dry the grain","process":"harvest","text":"A combine cuts the crop directly, or picks up windrows that have dried in the field. Stored grain must not exceed 13% moisture, or it spoils.","inputs":[],"spec":"13% moisture or below"}],"facts":["Winter oats can be grazed for a while, then left to head out for grain, or plowed under in spring as green fertilizer.","Oats are thought to have emerged as a secondary crop, from what was once a weed in fields of wheat and other cereals."],"where":[{"place":"Canada","share":"15% of world output"},{"place":"Russia","share":"13%"}],"whereNote":"2024, share of the 22 million tonnes of oats produced worldwide.","sources":[{"title":"Oat","url":"https://en.wikipedia.org/wiki/Oat"},{"title":"Combine harvester","url":"https://en.wikipedia.org/wiki/Combine_harvester"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"office-chair","name":"Office chair","kind":"product","category":"machines","title":"How office chairs are made","url":"https://assemblyline.org/make/office-chair","stations":7,"upstream":54,"downstream":0,"depth":7,"dek":"The height adjuster in an office chair is a sealed cylinder of compressed gas.","answer":"Plastic is injection-molded into the shell and often the five-star base, while metal bases are die-cast. Two-part polyurethane poured into a heated mold makes the cushion, and a sewn cover goes over it. Casters press into the base, a gas lift of sealed pressurized nitrogen drops into its center, and the seat sits on top.","aka":["desk chair","swivel chair","task chair"],"inputs":["polypropylene","nylon","aluminum","nitrogen","steel","polyurethane","polyester"],"uses":[],"grounds":["crude-oil","coal","air","water","natural-gas","bauxite","iron-ore","limestone","dolomite","manganese-ore","rock-salt","quartz","timber","sulfur","corn","sugarcane","sugar-beet"],"upstreamSlugs":["polypropylene","nylon","aluminum","nitrogen","steel","polyurethane","polyester","propylene","benzene","nitric-acid","ammonia","crude-oil","coal","petroleum-coke","alumina","air","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","chlorine","water","pet-plastic","naphtha","hydrogen","toluene","natural-gas","bauxite","caustic-soda","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","sulfuric-acid","rock-salt","p-xylene","ethylene","ethylene-glycol","quartz","charcoal","timber","sulfur","carbon-dioxide","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the seat shell","process":"mold","text":"Molten plastic, often polypropylene or glass-filled nylon, is injected into a steel mold to make the seat and back shells.","inputs":["polypropylene"]},{"name":"Make the star base","process":"mold","text":"A five-armed base is injection-molded from nylon, sometimes reinforced with glass fibers, or die-cast from aluminum and then machined and polished.","inputs":["nylon","aluminum"]},{"name":"Fill the gas lift","process":"fill","text":"Gas springs are sealed cylinders holding high-pressure gas, usually nitrogen, with a piston and some oil. Pulling the lever lets gas move from one side of the piston to the other, which raises or lowers the seat. Many chair makers buy these from specialists.","inputs":["nitrogen","steel"]},{"name":"Mold the seat cushion","process":"mold","text":"Two-part polyurethane is mixed and poured into a heated aluminum mold, where it expands and cures in minutes into a contoured cushion.","inputs":["polyurethane"]},{"name":"Cover the cushion","process":"sew","text":"Fabric is cut, sewn into a cover, wrapped over the foam and glued or stapled to the underside of the seat.","inputs":["polyester"]},{"name":"Assemble the chair","process":"assemble","text":"Casters press into the arms of the base, and the gas lift drops into the center hole. The tilt mechanism is bolted under the seat and seats onto the gas lift by a tapered fit.","inputs":[]},{"name":"Test on the line","process":"inspect","text":"Every adjustment and wheel is checked on the line. Sample chairs go through the destructive and durability tests of the ANSI/BIFMA X5.1 standard.","inputs":[]}],"facts":["Charles Darwin was one of the earliest known people to put wheels on a chair, to move around his study.","A swiveling chair with casters appears in a 1505 manuscript by Martin Loeffelholz von Kolberg."],"where":[],"whereNote":null,"sources":[{"title":"Office chair","url":"https://en.wikipedia.org/wiki/Office_chair"},{"title":"Gas spring","url":"https://en.wikipedia.org/wiki/Gas_spring"},{"title":"Polyurethane foam","url":"https://en.wikipedia.org/wiki/Polyurethane_foam"},{"title":"How Are Office Chairs Made? A Stage-by-Stage Guide","url":"https://www.ergoprise.com/blog/how-are-office-chairs-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"oil-palm-fruit","name":"Oil palm fruit","kind":"raw","category":"farm","title":"How oil palm fruit is grown and harvested","url":"https://assemblyline.org/make/oil-palm-fruit","stations":3,"upstream":0,"downstream":15,"depth":0,"dek":"One hectare of oil palm averages 20 tonnes of fruit a year, and the palm is harvested all year round.","answer":"Oil palms are single-stemmed palms that grow up to 20 meters tall and carry fruit in large bunches. A fruit takes 5 to 6 months to ripen after pollination, and the harvest runs year-round. Each hectare averages 20 tonnes of fruit, which yields 4,000 kg of palm oil and 750 kg of seed kernels.","aka":["palm fruit","oil palm farming","oil palm bunches","palm oil plantation","fresh fruit bunches"],"inputs":[],"uses":["palm-oil"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["palm-oil","soap","glycerin","margarine","instant-noodles","sandwich-cookie","popcorn","hazelnut-spread","toffee","toothpaste","sunscreen","chewing-gum","snow-globe","cough-syrup","gelatin-capsule"],"steps":[{"name":"Plant hybrid palms","process":"grow","text":"All modern commercial planting material is tenera palm or hybrids made by crossing thick-shelled dura with shell-less pisifera. The resulting palm bears thin-shelled fruit with more oil in the flesh.","inputs":[]},{"name":"Let insects pollinate","process":"grow","text":"The palm is pollinated almost entirely by insects, not wind. An African insect, Elaeidobius kamerunicus, was deliberately introduced to southeast Asia in 1981 with dramatic results.","inputs":[]},{"name":"Cut the ripe bunches","process":"harvest","text":"Fruit takes 5 to 6 months to mature after pollination, reddish and about the size of a large plum. Bunches are cut down all year, and the oil-rich flesh around a hard-shelled kernel gives two oils, palm oil and palm kernel oil.","inputs":[]}],"facts":["A bunch yields 17 to 27% palm oil by weight and 4 to 10% palm kernels.","Palm oil is reddish because of its high beta-carotene content.","Palm oil and kernel meal from the same hectare also supply livestock feed, as the kernel meal is processed for animal use."],"where":[{"place":"Indonesia","share":"57% of world palm oil output"},{"place":"Malaysia","share":"second largest, 19.7 million tonnes"}],"whereNote":"2023 to 2024, share of 77.3 million tonnes of palm oil produced worldwide.","sources":[{"title":"Elaeis guineensis","url":"https://en.wikipedia.org/wiki/Elaeis_guineensis"},{"title":"Palm oil","url":"https://en.wikipedia.org/wiki/Palm_oil"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"oled-screen","name":"OLED screen","kind":"product","category":"electronics","title":"How OLED screens are made","url":"https://assemblyline.org/make/oled-screen","stations":6,"upstream":42,"downstream":3,"depth":9,"dek":"Every pixel is a thin organic film that glows by itself, so there is no backlight at all.","answer":"An OLED screen starts with a glass sheet carrying a transistor grid. Transparent indium tin oxide forms the anode, thin organic films are deposited above it, and a metal cathode goes on top. Small-molecule films are evaporated in a vacuum, while polymer films can be spin-coated or inkjet printed.","aka":["organic LED","AMOLED","organic light-emitting diode display"],"inputs":["glass","indium-tin-oxide","aluminum"],"uses":["smartphone","television","smartwatch"],"grounds":["silica-sand","limestone","crude-oil","coal","rock-salt","water","trona","zinc-ore","tin-ore","bauxite","natural-gas","air","corn","sulfur","sugarcane","sugar-beet"],"upstreamSlugs":["glass","indium-tin-oxide","aluminum","silica-sand","soda-ash","limestone","indium","tin","photoresist","crude-oil","coal","petroleum-coke","alumina","rock-salt","water","ammonia","carbon-dioxide","lime","trona","zinc-ore","sulfuric-acid","tin-ore","coke","phenolic-resin","bauxite","caustic-soda","natural-gas","air","corn","yeast","sulfur","phenol","formaldehyde","molasses","benzene","propylene","methanol","sugarcane","sugar-beet","naphtha","hydrogen","toluene"],"downstreamSlugs":["smartphone","television","smartwatch"],"steps":[{"name":"Build the transistor grid","process":"etch","text":"A thin-film transistor backplane is etched onto glass so that each pixel can be switched on its own. This is the active-matrix form, called AMOLED.","inputs":["glass"]},{"name":"Lay a clear anode","process":"deposit","text":"Indium tin oxide is deposited as the anode because it is transparent and good at injecting positive charge into the organic layer.","inputs":["indium-tin-oxide"]},{"name":"Evaporate the organic films","process":"deposit","text":"Small-molecule materials are vapor-deposited in vacuum chambers, layer by layer, which keeps the film growth and the device build in one controlled environment. Polymer films, which would break apart in vacuum, are spin-coated or printed from solution instead.","inputs":[]},{"name":"Cap with a metal cathode","process":"deposit","text":"A low work function metal such as barium or calcium injects electrons. It is reactive, so it gets a capping layer of aluminum that also reflects light forward.","inputs":["aluminum"]},{"name":"Seal against air","process":"laminate","text":"The organic stack is sealed beneath a barrier layer or glass cover, because moisture and oxygen degrade the films.","inputs":[]},{"name":"Test every pixel","process":"inspect","text":"Panels are lit and inspected for dead pixels and uneven color before they are shipped.","inputs":[]}],"facts":["The first commercial shipment of inkjet-printed OLED panels began on 5 December 2017.","In 1990, researchers at Cambridge reported a green polymer OLED using films only 100 nm thick.","OLED pixels emit their own light, so black pixels simply switch off."],"where":[],"whereNote":null,"sources":[{"title":"OLED","url":"https://en.wikipedia.org/wiki/OLED"},{"title":"Liquid-crystal display","url":"https://en.wikipedia.org/wiki/Liquid-crystal_display"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"olive-oil","name":"Olive oil","kind":"product","category":"food","title":"How olive oil is made","url":"https://assemblyline.org/make/olive-oil","stations":6,"upstream":1,"downstream":0,"depth":1,"dek":"Extra virgin olive oil is only crushed olives and a spinning centrifuge, with no chemistry at all.","answer":"Olives are crushed to a paste, stirred slowly so the tiny oil droplets merge, then spun in a centrifuge that separates oil from water and solids. If the oil is made only by mechanical means it counts as virgin, and extra virgin must also pass chemical and taste tests, including free acidity under 0.8 percent.","aka":["extra virgin olive oil","EVOO","virgin olive oil"],"inputs":["olives"],"uses":[],"grounds":["olives"],"upstreamSlugs":["olives"],"downstreamSlugs":[],"steps":[{"name":"Strip the leaves and wash","process":"wash","text":"Harvested olives pass through blowers and washers that remove leaves, twigs and dirt before milling. The quality of the oil depends heavily on the weather, the cultivar and the time of harvest.","inputs":["olives"]},{"name":"Crush to a paste","process":"crush","text":"The whole fruit, pit included, is ground. Traditional stone mills keep the paste under the stones for 30 to 40 minutes. Modern hammer, blade or disk mills reduce the olives to paste in seconds.","inputs":[]},{"name":"Stir the paste slowly","process":"knead","text":"The paste is churned gently in warmed troughs, usually for 20 to 30 minutes. Small droplets of oil bump together and merge into large ones that are easy to separate.","inputs":[],"spec":"20 to 30 minutes"},{"name":"Spin out the oil","process":"separate","text":"A horizontal centrifuge called a decanter whirls the paste so the heavy solids, the water and the oil split into layers. Older mills pressed the paste on stacked fiber disks and let the oil settle slowly by gravity.","inputs":[]},{"name":"Polish and filter","process":"separate","text":"A second centrifuge clears out remaining water. Some oil is filtered to take out fine particles that shorten shelf life, and some is bottled unfiltered, which looks slightly cloudy.","inputs":[]},{"name":"Grade and bottle","process":"inspect","text":"Chemists test free acidity and tasters check for defects. Oil that fails the extra virgin standards is sold as a lower grade or refined and blended.","inputs":[]}],"facts":["The world's largest olive oil mill, in Villacarrillo in Jaen, Spain, can process 2,500 tonnes of olives a day.","Spain alone makes 24% of the world's olive oil."],"where":[{"place":"Spain","share":"24% of world production"}],"whereNote":"2022 world production of 2.7 million tonnes.","sources":[{"title":"Olive oil","url":"https://en.wikipedia.org/wiki/Olive_oil"},{"title":"Vegetable oil","url":"https://en.wikipedia.org/wiki/Vegetable_oil"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"olives","name":"Olives","kind":"raw","category":"farm","title":"How olives are grown and harvested","url":"https://assemblyline.org/make/olives","stations":5,"upstream":0,"downstream":1,"depth":0,"dek":"Hand-picking California table olives can eat 50 to 75% of the gross return, so growers now hedge trees for machines.","answer":"Olive growers root cuttings or bud and graft their trees, because trees from seed or suckers yield poorly. In the Mediterranean, harvest starts in autumn, mostly by shaking the tree or its branches. In California, where table olives come off immature and bruise easily, growers top and hedge trees so trunk shakers and canopy machines can reach the fruit. About 80% of all olives become oil.","aka":["olive farming","olive harvest","olive grove","olive trees"],"inputs":[],"uses":["olive-oil"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["olive-oil"],"steps":[{"name":"Propagate the trees","process":"grow","text":"Olives root easily from cuttings and layering, and they throw up suckers from a cut stump. Trees from suckers or seed give poor yields, though, so growers root cuttings or bud and graft onto better stock.","inputs":[]},{"name":"Wait for flower and fruit","process":"grow","text":"Small white flowers form on the previous year's wood, and the buds take 4 to 6 weeks to grow before they bloom. The fruit that follows is a small drupe, 1 to 2.5 cm long when ripe.","inputs":[]},{"name":"Hedge for the harvester","process":"cut","text":"Older California orchards have tall trees, with fruit on flexible hanging shoots that machines handle badly. Growers adapt them by hand-pruning limbs in the way and hedging the rows. A Tulare County trial topped trees at 12 ft and hedged alternate sides each year, with no significant change in cumulative yield.","inputs":[]},{"name":"Shake trunks or canopies","process":"harvest","text":"Most olives come off by shaking the tree or single branches. A trunk shaker suits upright trees with smooth trunks, and a canopy-contact machine suits hedgerows, each carried on a mobile platform with a catch frame. University of California trials of both removed at least 75% of the fruit.","inputs":[],"spec":"at least 75% of fruit removed in UC trials"},{"name":"Pick table fruit gently","process":"harvest","text":"Damaged table olives turn bitter, so pickers use baskets hung around the neck. On ladders, others milk fruit into a sack tied at the waist. In mountainous parts of Italy, Croatia and Greece the crop is still picked by hand, because machines cannot work the terrain.","inputs":[]}],"facts":["Commercial production is led by Spain, Italy and Greece.","In a 2012 California evaluation, a trunk shaker cost about $200 a ton, against an estimated $400 a ton for hand picking.","Manzanillo table olives come off while immature, so they cling harder than ripe fruit and take about 0.5 kg of pull to remove."],"where":[],"whereNote":null,"sources":[{"title":"Olive","url":"https://en.wikipedia.org/wiki/Olive"},{"title":"Innovative Progress in the Mechanical Harvest of California Black Ripe Olives, UC Agriculture and Natural Resources","url":"https://www.ucanr.edu/blog/topics-subtropics/article/innovative-progress-mechanical-harvest-california-black-ripe-olives"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"medal","name":"Olympic-style medal","kind":"product","category":"hardware","title":"How Olympic-style medals are made","url":"https://assemblyline.org/make/medal","stations":8,"upstream":22,"downstream":0,"depth":4,"dek":"Vancouver's gold medals spent about 100 minutes in a plating bath to gain a gold skin 20 micrometers thick.","answer":"Olympic medals are struck much the way coins are. A mint cuts and hardens steel dies, prepares blanks from rolled metal, and a hydraulic press squeezes each blank between the dies, sometimes several times with annealing in between. Gold medals are mostly silver, electroplated with gold. Silver medals stay silver, and bronze is a copper alloy. A ribbon fitting and name engraving come near the end.","aka":["gold medal","Olympic medal"],"inputs":["silver","copper","zinc","tin","gold"],"uses":[],"grounds":["silver-ore","lead-ore","zinc-ore","copper-ore","water","air","tin-ore","gold-ore","sulfur","limestone","coal","rock-salt"],"upstreamSlugs":["silver","copper","zinc","tin","gold","silver-ore","lead-ore","zinc-ore","copper-ore","sulfuric-acid","lime","water","oxygen","air","tin-ore","coke","gold-ore","chlorine","sulfur","limestone","coal","rock-salt"],"downstreamSlugs":[],"steps":[{"name":"Cut the steel dies","process":"machine","text":"Each design becomes a 3D model, then tools cut it into steel, which is heat treated and hardened. For Vancouver 2010 the Royal Canadian Mint milled 12 undulated dies by CNC.","inputs":[]},{"name":"Cast and roll the metal","process":"roll","text":"Cast bar is rolled to the required thickness. Gold and silver medals are mainly sterling silver, while bronze ones are a mix of copper, zinc and tin.","inputs":["silver","copper","zinc","tin"]},{"name":"Prepare the blanks","process":"stamp","text":"Blanks are cut from the rolled metal to precise width and thickness. At the Austrian Mint they are also rimmed, annealed to relax the hardened grain, and then ball polished, washed or brushed.","inputs":[]},{"name":"Strike between the dies","process":"press","text":"A press drives the dies into the blank, and the metal takes the design. The Austrian Mint uses up to 12,000 kN per strike, far more than for coins. Vancouver's blanks were triple struck three separate times, polished and annealed between groups.","inputs":[],"spec":"up to 12,000 kN per strike"},{"name":"Fix the ribbon fitting","process":"assemble","text":"Some medals get ribbon eyes soldered on after finishing by hand. Vancouver's mint pressed a hanger into the body and tested it to withstand 200 lb of pressure.","inputs":[]},{"name":"Clean for plating","process":"wash","text":"Gold-medal bodies are degreased, cleaned again electrically, and passed through an acid dip that removes any tarnish.","inputs":[]},{"name":"Plate the gold","process":"coat","text":"A thin first gold layer gives good adhesion and traps stray contamination. A richer bath then builds the deposit to its final thickness, with each medal hung on a rack. The IOC asks for at least 6 grams of gold.","inputs":["gold"],"spec":"at least 6 grams of gold"},{"name":"Seal and test","process":"inspect","text":"A clear protective coat guards the surface against tarnish. Vancouver's were cold-tested to -20 °C, and winners' names and results are laser engraved. The ribbon is threaded through last.","inputs":[]}],"facts":["The International Olympic Committee requires a gold medal to be at least 92.5% silver plated with 6 grams of gold.","Medals must be at least 60 mm in diameter and 3 mm thick.","Vancouver 2010 produced 1,014 unique medal designs by cropping parts of two large artworks."],"where":[],"whereNote":null,"sources":[{"title":"Olympic medal","url":"https://en.wikipedia.org/wiki/Olympic_medal"},{"title":"Precious Medals, Products Finishing","url":"https://www.pfonline.com/articles/precious-medals"},{"title":"Contract Manufacturing of Medals, Austrian Mint","url":"https://www.muenzeoesterreich.com/en/info-centre/for-companies/contract-manufacturing-of-medals"},{"title":"What are Olympic Medals really made of?, AZoM","url":"https://www.azom.com/article.aspx?ArticleID=6046"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"onions","name":"Onions","kind":"raw","category":"farm","title":"How onions are grown","url":"https://assemblyline.org/make/onions","stations":5,"upstream":0,"downstream":1,"depth":0,"dek":"An onion's papery skin is finished in a shed, where hot air dries its outer scales into a wrapper for the wet flesh.","answer":"A rope dragged across the bed rolls ripe onions out of the soil just as a blade slices under them. Georgia's sweet crop mostly starts as seedlings pulled from dense beds and replanted in rows. After days drying in the field, the bulbs lose roots and tops, then sit in a stream of warm air until their outer scales turn brittle.","aka":["bulb onion","common onion","Allium cepa","dry onion"],"inputs":[],"uses":["salsa"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["salsa"],"steps":[{"name":"Sow the seedling beds","process":"grow","text":"Georgia growers sow seed in September in fumigated, weed-free beds. After 8 to 10 weeks each seedling is about as thick as a pencil. Crews pull them, tie them in bundles of 50 to 80 with a rubber band, and chop off roughly half the tops.","inputs":[],"spec":"8 to 10 weeks in the bed"},{"name":"Set out the rows","process":"grow","text":"Seedlings go into raised beds about 4 ft wide, four rows to a bed, with a gap of 4.5 to 6 in. between plants. Day length then tells the plant when to start swelling a bulb, which is why long-day and short-day varieties suit different regions.","inputs":[]},{"name":"Undercut the mature bulbs","process":"harvest","text":"Growers pinch the necks to judge ripeness, since a limp neck means a mature plant. A rotating bar or fixed blade runs about 1 in. below the bulbs while a dragged rope rolls them out of the ground to dry for 3 to 5 sunny days.","inputs":[]},{"name":"Clip roots and tops","process":"cut","text":"Shears or a mechanical topper take the roots off completely and leave 1 to 2 in. of neck. Too short a neck invites disease. Bulbs ride to the packing shed in bags or large bins, and every hard drop along the way bruises them.","inputs":[]},{"name":"Cure under forced air","process":"dry","text":"Fans push heated air through stacked bins for 24 to 48 hours. Only the outer scales, roots and neck dry out, so the flesh stays wet inside a brittle skin. Workers then sort the bulbs by size and quality before shipping or cold storage.","inputs":[],"spec":"97 to 100 °F for 24 to 48 hours"}],"facts":["Traces of onion were found in the eye sockets of the Egyptian pharaoh Ramesses IV.","New Zealand researchers built a genetically modified \"no tears\" onion in 2008 by blocking the enzyme behind the sting.","Vidalia onions began in 1931, when a Georgia grower named Mose Coleman planted a mild short-day crop in Toombs County."],"where":[{"place":"China","share":"listed first among top producers"},{"place":"India","share":"listed second"},{"place":"United States","share":"listed third"},{"place":"Turkey","share":"listed fourth"}],"whereNote":"Top global onion producers in 2021, in the order Wikipedia lists them. The source gives no shares.","sources":[{"title":"Vidalia Onion Production Guide, University of Georgia Extension","url":"https://extension.uga.edu/publications/detail.html?number=B1198"},{"title":"Onion Production, Penn State Extension","url":"https://extension.psu.edu/onion-production"},{"title":"Onion","url":"https://en.wikipedia.org/wiki/Onion"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"optical-fiber","name":"Optical fiber","kind":"product","category":"minerals","title":"How optical fiber is made","url":"https://assemblyline.org/make/optical-fiber","stations":6,"upstream":25,"downstream":0,"depth":6,"dek":"A telecom fiber is pulled from a glass rod built layer by layer out of gas, and it ends up about as thin as a hair.","answer":"Optical fiber starts as a large glass preform made by burning silicon and germanium chlorides with oxygen so fine glass soot settles in layers. The preform is heated to a clear solid, then pulled in a drawing tower into a strand about the size of a human hair. Plastic coatings go on during the draw.","aka":["fiber optic cable","optical fibre","fiber-optic strand"],"inputs":["glass","oxygen","germanium"],"uses":[],"grounds":["silica-sand","limestone","air","zinc-ore","rock-salt","water","trona","sulfur","natural-gas","corn","sugarcane","sugar-beet"],"upstreamSlugs":["glass","oxygen","germanium","silica-sand","soda-ash","limestone","air","zinc-ore","sulfuric-acid","hydrochloric-acid","hydrogen","rock-salt","water","ammonia","carbon-dioxide","lime","trona","sulfur","chlorine","natural-gas","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Burn gas into glass soot","process":"react","text":"A hollow glass tube about 40 centimeters long turns slowly on a lathe. Silicon tetrachloride and germanium tetrachloride gas flow in with oxygen while a burner outside heats the tube to about 1,600 °C. The gases react and drop a fine soot of glass onto the inner wall.","inputs":["glass","oxygen","germanium"],"spec":"about 1,600 °C"},{"name":"Layer the core and cladding","process":"deposit","text":"The torch travels the length of the tube again and again, melting each pass of soot into a clear layer. Changing the gas mix from layer to layer tunes the refractive index precisely, so light stays trapped in the center.","inputs":[]},{"name":"Collapse it to a solid rod","process":"melt","text":"When enough layers are down, the preform is consolidated into a transparent, solid rod at about 1,500 °C. Surface flaws on the preform would carry into the fiber, so careful polishing matters.","inputs":[],"spec":"about 1,500 °C"},{"name":"Pull it in the tower","process":"draw","text":"The preform hangs in a drawing tower. Its tip is heated, and the fiber is pulled out like a string. The tension on the strand is controlled to keep the thickness uniform.","inputs":[]},{"name":"Coat the strand","process":"coat","text":"Two layers of UV-cured urethane acrylate go on while the fiber is still being drawn. The inner layer absorbs shocks, and the outer layer guards against knocks and may be colored to tell strands apart in a cable.","inputs":[]},{"name":"Test the loss","process":"inspect","text":"Fiber is proof-tested and measured for light loss. A good modern strand loses so little that, at 0.148 dB/km, a 10 km length still passes nearly 71% of the light.","inputs":[],"spec":"0.148 dB/km"}],"facts":["In 1965 Charles Kao and George Hockham proposed that impurities, not physics, were what limited fiber, and the 20 dB/km loss target was first reached in 1970.","Early high-quality fiber could only be drawn at two meters per second, and by 1983 Corning had raised that to over 50 meters per second.","A fiber fuse, where damage vaporizes the glass, crawls back toward the laser at 1–3 meters per second."],"where":[],"whereNote":null,"sources":[{"title":"Optical fiber","url":"https://en.wikipedia.org/wiki/Optical_fiber"},{"title":"Glass","url":"https://en.wikipedia.org/wiki/Glass"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"orange-juice","name":"Orange juice","kind":"product","category":"drink","title":"How orange juice is made","url":"https://assemblyline.org/make/orange-juice","stations":8,"upstream":2,"downstream":0,"depth":1,"dek":"Orange juice can sit in oxygen-free tanks for up to a year, and then get its fresh flavor sprayed back on.","answer":"Oranges are washed, inspected and squeezed by machines that ream out the juice. A screen removes seeds and heavy pulp. The juice is heated to destroy enzymes, stripped of air and either chilled and stored as not-from-concentrate or boiled under vacuum to a thick concentrate. Lost aromas are added back before the juice is packed.","aka":["OJ","not from concentrate","frozen concentrated orange juice"],"inputs":["oranges","water"],"uses":[],"grounds":["oranges","water"],"upstreamSlugs":["oranges","water"],"downstreamSlugs":[],"steps":[{"name":"Inspect and wash fruit","process":"wash","text":"Trucks tip oranges onto roller conveyors where inspectors pull out moldy, rotten or split fruit. The rest is washed and sorted by size so the extractors can grip it evenly.","inputs":["oranges"]},{"name":"Peel off the oil","process":"press","text":"Rollers scrub oil from the peel before the juice is taken. The cold-pressed orange oil is saved, because it is the main ingredient of the flavor packs added later.","inputs":[]},{"name":"Ream out the juice","process":"press","text":"Machines halve the oranges and press out the juice, or push a tube through each fruit. The fruit is squeezed gently so the bitter peel does not leak into the juice.","inputs":[]},{"name":"Screen out the solids","process":"separate","text":"Finishers push the juice through a perforated screen with a conical screw. Seeds and large pieces of pulp are removed, and some pulp is added back later for pulpy juice.","inputs":[]},{"name":"Strip out the air","process":"refine","text":"A vacuum chamber removes dissolved air so the juice does not foam when it is filled, and so it keeps longer.","inputs":[]},{"name":"Flash-heat the juice","process":"pasteurize","text":"Juice is quickly heated to inactivate the enzymes that would spoil it. The heating also destroys microbes. Quick heating keeps the damage to flavor and vitamins small.","inputs":[],"spec":"197 °F for about 40 seconds"},{"name":"Concentrate under vacuum","process":"refine","text":"Juice for concentrate is boiled at low temperature under vacuum until most of the water is gone. The thick result is about 65% sugar by weight and is stored in a freezer.","inputs":[],"spec":"stored at about 10 °F (−12 °C)"},{"name":"Restore the flavor","process":"mix","text":"Processing strips out aroma, so makers blend in a flavor pack. It is built from compounds taken from orange peel oil. Concentrate is diluted with water, and the juice is chilled and packed.","inputs":["water"]}],"facts":["Not-from-concentrate juice is often held in aseptic tanks stripped of oxygen for up to a year.","Frozen concentrated orange juice was developed in 1948 at the University of Florida's Citrus Research and Education Center.","Futures contracts on frozen concentrated orange juice have traded in New York since 1966.","Flavor packs are not mentioned on the label."],"where":[],"whereNote":null,"sources":[{"title":"Orange juice","url":"https://en.wikipedia.org/wiki/Orange_juice"},{"title":"Pasteurization","url":"https://en.wikipedia.org/wiki/Pasteurization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"oranges","name":"Oranges","kind":"raw","category":"farm","title":"How oranges are grown and harvested","url":"https://assemblyline.org/make/oranges","stations":3,"upstream":0,"downstream":9,"depth":0,"dek":"Every commercial orange tree is a graft, and ripe oranges are often gassed with ethylene to turn them orange.","answer":"Orange trees are propagated by grafting a bud from a mature variety onto a rootstock grown from seed, so every tree gives identical fruit. Oranges are picked when mature, often by shaking the tree canopy with a machine. Green skin may be turned orange afterward with ethylene gas.","aka":["orange farming","orange harvest","citrus grove","sweet oranges"],"inputs":[],"uses":["perfume","orange-juice","cola"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["perfume","orange-juice","cola","shampoo","deodorant","air-freshener","dish-soap","hairspray","foundation-makeup"],"steps":[{"name":"Graft onto rootstock","process":"grow","text":"Growers first raise a rootstock from seed. When it is about one year old, the leafy top is cut off and a bud from a mature cultivar is attached, which guarantees the same yield and fruit traits and disease resistance every year.","inputs":[]},{"name":"Shake the canopy","process":"harvest","text":"Canopy-shaking machines are used increasingly in Florida. They push tines six to seven feet long through the tree to shake the fruit down at a steady stroke and frequency. Oranges are picked once pale orange.","inputs":[]},{"name":"Degreen with ethylene","process":"dry","text":"Ripe oranges often have green or yellow-green skin. Ethylene gas turns the skin orange, a step called degreening, gassing, sweating or curing. Laws forbid harvesting immature fruit for human consumption in several US states.","inputs":[]}],"facts":["Citrus greening disease has been the most serious threat to orange production since 2010, and in affected areas trees live only five to eight years.","Oranges can be stored in controlled-atmosphere chambers for up to twelve weeks after harvest.","The earliest mention of the sweet orange is in Chinese literature in 314 BC."],"where":[{"place":"Brazil","share":"23% of world output"},{"place":"China","share":"second largest producer"},{"place":"Mexico","share":"third largest producer"},{"place":"Egypt","share":"fourth largest producer"}],"whereNote":"2024, share of the 67 million tonnes of oranges produced worldwide.","sources":[{"title":"Orange (fruit)","url":"https://en.wikipedia.org/wiki/Orange_(fruit)"},{"title":"Citrus","url":"https://en.wikipedia.org/wiki/Citrus"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rocket","name":"Orbital rocket","kind":"product","category":"machines","title":"How orbital rockets are made","url":"https://assemblyline.org/make/rocket","stations":7,"upstream":67,"downstream":0,"depth":9,"dek":"To reach orbit a rocket has to climb to about 150 km and then reach a sideways speed of at least 7,814 m/s.","answer":"An orbital rocket is mostly thin-walled tanks, with engines at the bottom and a payload on top. Plants weld aluminum tank sections, build engines from precisely machined parts, and join the stages and avionics. Engines are fired on a test stand, and the stages are then shipped and stacked at the launch site.","aka":["launch vehicle","space rocket","booster"],"inputs":["aluminum","copper","printed-circuit-board","microchip","copper-wire","oxygen","hydrogen"],"uses":[],"grounds":["crude-oil","coal","copper-ore","water","air","natural-gas","bauxite","sulfur","silica-sand","limestone","quartz","tin-ore","gold-ore","rock-salt","trona","lead-ore","silver-ore","zinc-ore","corn","timber","sugarcane","sugar-beet"],"upstreamSlugs":["aluminum","copper","printed-circuit-board","microchip","copper-wire","oxygen","hydrogen","crude-oil","coal","petroleum-coke","alumina","copper-ore","water","air","sulfuric-acid","fiberglass","epoxy","photoresist","solder","silicon-wafer","tin","gold","natural-gas","bauxite","caustic-soda","lime","sulfur","silica-sand","limestone","soda-ash","phenol","propylene","acetone","chlorine","phenolic-resin","lead","silver","polysilicon","quartz","argon","tin-ore","coke","gold-ore","zinc","rock-salt","ammonia","carbon-dioxide","trona","benzene","naphtha","formaldehyde","lead-ore","silver-ore","zinc-ore","silicon","hydrochloric-acid","trichlorosilane","nitrogen","corn","yeast","toluene","methanol","charcoal","timber","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Form and weld the tanks","process":"weld","text":"Most of a rocket by volume is propellant tank. Thin aluminum alloy sheets are formed into barrels and domes, then welded into tall cylinders. They must be light and still hold pressure.","inputs":["aluminum"]},{"name":"Machine the engine parts","process":"machine","text":"Combustion chambers, injectors, nozzles and turbopumps are machined to tight tolerances. The engine's injectors are arrays of holes that spray propellants into the chamber.","inputs":[]},{"name":"Assemble the engines","process":"assemble","text":"Pumps, chambers and nozzles are joined with their plumbing and valves into complete engines. A liquid engine needs a way to push propellant in at higher pressure than the chamber.","inputs":["copper"]},{"name":"Wire up the avionics","process":"assemble","text":"Computers, sensors, radios and guidance electronics are installed in the upper stage and in a ring around the base.","inputs":["printed-circuit-board","microchip","copper-wire"]},{"name":"Fire the engines on a stand","process":"inspect","text":"Engines, and sometimes whole stages, are bolted to a test stand and fired to verify thrust and cooling before flight.","inputs":["oxygen"]},{"name":"Join the stages at the pad","process":"assemble","text":"Stages travel to the launch site and are stacked one on top of another with the payload at the very top.","inputs":[]},{"name":"Fill the tanks","process":"fill","text":"Shortly before launch, super-cold liquid propellants, such as liquid oxygen and a fuel, are pumped into the tanks. The vehicle is then ready to count down.","inputs":["oxygen","hydrogen"]}],"facts":["A modified SS-520 sounding rocket put a 4-kilogram payload, TRICOM-1R, into orbit in 2018.","As of 2023, every reusable launch vehicle that had operated was only partially reusable."],"where":[],"whereNote":null,"sources":[{"title":"Launch vehicle","url":"https://en.wikipedia.org/wiki/Launch_vehicle"},{"title":"Rocket engine","url":"https://en.wikipedia.org/wiki/Rocket_engine"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"oxygen","name":"Oxygen gas","kind":"material","category":"chemicals","title":"How industrial oxygen is made","url":"https://assemblyline.org/make/oxygen","stations":5,"upstream":1,"downstream":380,"depth":1,"dek":"Industrial oxygen is liquefied air, boiled apart in a column so tall that nitrogen and oxygen separate by height.","answer":"Industrial oxygen is made by cooling air until it liquefies and then distilling it in tall columns. Oxygen boils at a higher temperature than nitrogen, so it collects as a liquid at the bottom. The oxygen is drawn off at purities between 97.5% and 99.5%, then trucked as a liquid or piped to nearby steel and chemical plants.","aka":["O2","liquid oxygen","LOX"],"inputs":["air"],"uses":["titanium-dioxide","microchip","steel","stainless-steel","copper","optical-fiber","rocket","steel-scrap","neon","polyvinyl-alcohol","ethylene-glycol","wood-pulp"],"grounds":["air"],"upstreamSlugs":["air"],"downstreamSlugs":["titanium-dioxide","microchip","steel","stainless-steel","copper","optical-fiber","rocket","steel-scrap","neon","polyvinyl-alcohol","ethylene-glycol","wood-pulp","toothpaste","sunscreen","lipstick","nail-polish","ink","paint","crayon","pencil-eraser","candy-coated-chocolate","foundation-makeup","pvc-pipe","e-reader","pigment","hearing-aid","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","smartwatch","wireless-earbuds","phone-charger","usb-cable","digital-camera","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","toothbrush","lithium-ion-cell","ev-battery","aa-battery","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","loudspeaker","syringe","washing-machine","electric-kettle","kitchen-knife","fork","razor-blade","fountain-pen","thermos","water-bottle","pressure-cooker","blender","asthma-inhaler","memory-chip","printed-circuit-board","camera-sensor","solar-panel","refrigerator","microwave-oven","copper-wire","brass","bronze","solder","faucet","coin","gold-ring","air-conditioner","flute","medal","bell","light-switch","power-outlet","brake-pad","jeans","cast-iron-pan","neon-sign","pvb","banknote","pet-plastic","spandex","kitchen-sponge","sanitary-pad","cellulose-acetate","paper","cardboard","toilet-paper","facial-tissue","rayon","diaper","plastic-bag","tin-can","aluminum-can","windshield","golf-ball","baseball","basketball","soccer-ball","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","cardboard-box","newspaper","book","sticky-notes","playing-cards","t-shirt","umbrella","pencil","mirror","car","wooden-chair","ceiling-fan","water-heater","tennis-racket","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","coil-spring","wheelbarrow","fire-extinguisher","suspension-bridge-cable","aluminum-window-frame","mascara","pvc","abs-plastic","lego-brick","lcd-screen","porcelain","chalk","candy-cane","sprinkles","plastic-straw","printer-toner","eyeshadow","towel","treadmill","safety-pin","hinge","saw-blade","shovel","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","clothespin","staple","sofa","slinky","cello","guitar-string","bolt","chain","chain-link-fence","mattress","concrete","skyscraper","roller-skates","wine","bourbon","scotch","cognac","port-wine","led-bulb","pinball-machine","smoke-detector","headphones","toaster","power-cable","microphone","trumpet","garden-hose","key","handbag","zipper","bronze-statue","polyester","plastic-bottle","3d-printer-filament","bottled-water","leggings","swimsuit","sunglasses","shoelace","soap","adhesive-bandage","drywall","popcorn","fireworks","paper-straw","paper-bag","egg-carton","tampon","cotton-swab","envelope","duct-tape","plastic-wrap","clear-tape","cake-mix","soda","energy-drink","hair-dye","match","leather-shoe","cotton-candy","pillow","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","deodorant","cola","sparkling-water","beer","hard-cider","root-beer","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","detergent","nitrile-glove","donut","corn-flakes","candle","salsa","fish-sticks","zip-bag","mouthwash","cough-syrup","football","volleyball","yoga-mat","inflatable-pool-toy","sailboat","champagne","down-jacket","raincoat","backpack","kite","wet-wipes","canoe","hoodie","curtain","sneaker","button","thread","teddy-bear","shampoo","aspirin","bleach","vitamin-c","ketchup","dish-soap","toffee","dress-shirt","suit","baseball-cap","bike-helmet","silk-tie","winter-gloves","wallet","hiking-boots","felt-hat","blanket","socks","sweater","flour","bread","instant-noodles","tortilla","croissant","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","modeling-clay","licorice"],"steps":[{"name":"Compress the air","process":"press","text":"Outside air is drawn in and compressed. The compressor supplies the energy that the plant's refrigeration needs, so no separate cooling machine is required.","inputs":["air"]},{"name":"Clean out moisture and gas","process":"wash","text":"Beds of molecular sieve adsorb water vapor, carbon dioxide and heavy hydrocarbons, none of which may reach the cold section of the plant.","inputs":[]},{"name":"Cool it until it liquefies","process":"chill","text":"Air is cooled against the cold gases leaving the plant, and expansion turbines chill it further. Part of the air becomes a pale blue liquid enriched in oxygen.","inputs":[]},{"name":"Distill in two stacked columns","process":"refine","text":"A high-pressure column and a low-pressure column work together. Their shared condenser runs on a temperature difference of just one or two kelvins, so oxygen drains out at the bottom as nitrogen vents off the top.","inputs":[]},{"name":"Fill tankers and pipelines","process":"fill","text":"Liquid oxygen is stored in insulated tanks and loaded onto tankers. Customers near the plant, such as steel mills, are connected by pipe.","inputs":[]}],"facts":["Hydrocarbons are scrubbed out of the air before it is liquefied, because they could build up in the liquid oxygen and become an explosion hazard.","Almost all the oxygen in Earth's air was made by photosynthesis, and it would vanish if living things did not keep replacing it."],"where":[],"whereNote":null,"sources":[{"title":"Air separation","url":"https://en.wikipedia.org/wiki/Air_separation"},{"title":"Oxygen","url":"https://en.wikipedia.org/wiki/Oxygen"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pacemaker","name":"Pacemaker","kind":"product","category":"body-health","title":"How pacemakers are made","url":"https://assemblyline.org/make/pacemaker","stations":7,"upstream":72,"downstream":0,"depth":9,"dek":"A pacemaker battery's cathode is poured in molten, then hardens inside a cell sealed against moisture.","answer":"Three parts are built separately, often with help from outside suppliers: a lithium-iodine battery, insulated metal leads and a circuit board smaller than a postage stamp. Workers join battery and board, close them in a titanium case made in pieces, and add a fitting where the leads connect. Each device is tested repeatedly, including under humidity and stress.","aka":["artificial cardiac pacemaker","heart pacemaker"],"inputs":["polyurethane","printed-circuit-board","microchip","solder","titanium"],"uses":[],"grounds":["water","titanium-ore","crude-oil","air","rock-salt","copper-ore","silica-sand","limestone","quartz","tin-ore","coal","gold-ore","lead-ore","silver-ore","zinc-ore","dolomite","natural-gas","sulfur","trona","bauxite","timber","corn","sugarcane","sugar-beet"],"upstreamSlugs":["polyurethane","printed-circuit-board","microchip","solder","titanium","propylene","nitric-acid","chlorine","water","copper","fiberglass","epoxy","photoresist","silicon-wafer","oxygen","tin","aluminum","gold","lead","silver","titanium-ore","magnesium","argon","naphtha","crude-oil","ammonia","air","rock-salt","sulfuric-acid","copper-ore","silica-sand","limestone","soda-ash","phenol","acetone","caustic-soda","phenolic-resin","polysilicon","quartz","tin-ore","coke","coal","petroleum-coke","alumina","gold-ore","lime","zinc","lead-ore","silver-ore","zinc-ore","dolomite","silicon","hydrogen","natural-gas","sulfur","carbon-dioxide","trona","benzene","formaldehyde","hydrochloric-acid","trichlorosilane","nitrogen","bauxite","charcoal","timber","corn","yeast","toluene","methanol","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Pour the battery","process":"melt","inputs":[],"text":"Iodine and a polymer are heated into a molten blend and poured into a half-moon cell that already holds the lithium anode and a collector screen. It solidifies into the cathode, and the cell is sealed airtight."},{"name":"Extrude the lead wires","process":"extrude","inputs":["polyurethane"],"text":"Molten metal alloy is pushed through a small opening to make wire. Many wires are bundled and insulated with a polymer such as polyurethane, then one end gets a shaped tip and the other a connector."},{"name":"Build the circuit board","process":"assemble","inputs":["printed-circuit-board","microchip","solder"],"text":"Semiconductor chips, resistors and capacitors are placed on a tiny mapped board and fixed with as few solder joints as possible, forming one complex circuit.","spec":"under 2 sq cm"},{"name":"Form the shell pieces","process":"press","inputs":["titanium"],"text":"The case is typically titanium or a titanium alloy, made in several pieces so the parts can go in before it closes."},{"name":"Join battery and circuit","process":"assemble","inputs":[],"text":"With every component ready, battery and circuit are wired together and set into the metal case."},{"name":"Seal and add fitting","process":"assemble","inputs":[],"text":"The case pieces are sealed together around the electronics, and a fitting is attached to give the leads a place to connect."},{"name":"Test and pack","process":"inspect","inputs":[],"text":"Visual and electrical checks run through the whole line. Finished devices are tested again, some under high humidity and stress, and packed with their accessories."}],"facts":["In the late 1960s some pacemakers were powered by heat from plutonium-238 inside a titanium case, until the lithium iodide cell arrived in 1971.","Early pacemakers failed because water vapor from body fluids diffused through their epoxy coating, which is why makers moved to hermetically sealed metal cases.","In 1932, American physiologist Albert Hyman described a pacing instrument driven by a hand-cranked, spring-wound motor."],"where":[],"whereNote":null,"sources":[{"title":"Pacemaker (How Products Are Made)","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/pacemaker"},{"title":"Artificial cardiac pacemaker","url":"https://en.wikipedia.org/wiki/Artificial_cardiac_pacemaker"},{"title":"Implantable cardioverter-defibrillator","url":"https://en.wikipedia.org/wiki/Implantable_cardioverter-defibrillator"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"padlock","name":"Padlock","kind":"product","category":"hardware","title":"How padlocks are made","url":"https://assemblyline.org/make/padlock","stations":7,"upstream":76,"downstream":0,"depth":11,"dek":"The classic padlock body is a stack of punched steel plates riveted together like a deck of cards.","answer":"A laminated padlock body is built from sheets of steel punched into plates, stacked and riveted so that a hollow in the middle holds the lock mechanism. The riveted body is electroplated against rust. The shackle is a hardened steel bar bent into a U, and a brass cylinder with pins and springs goes in last.","aka":["lock","laminated padlock"],"inputs":["sheet-steel","copper","tin","steel","brass","coil-spring"],"uses":[],"grounds":["copper-ore","water","air","tin-ore","zinc-ore","sulfur","coal","iron-ore","limestone","dolomite","manganese-ore","natural-gas","lead-ore","crude-oil","quartz","timber","bauxite","titanium-ore","rock-salt","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["sheet-steel","copper","tin","steel","brass","coil-spring","zinc","copper-ore","water","oxygen","air","sulfuric-acid","tin-ore","coke","pig-iron","magnesium","steel-scrap","lime","manganese","argon","lead","aluminum","steel-wire","paint","zinc-ore","sulfur","coal","iron-ore","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","lead-ore","crude-oil","petroleum-coke","alumina","titanium-dioxide","pigment","acrylic","tin-can","quartz","charcoal","timber","bauxite","caustic-soda","titanium-ore","chlorine","carbon-black","propylene","ammonia","methanol","tinplate","lacquer","ink","rock-salt","naphtha","ethanol","vegetable-oil","phenolic-resin","hydrogen","corn","sugarcane","yeast","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","molasses","benzene","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Punch the plates","process":"stamp","text":"A press cuts plates from steel sheet, each with a hole in the middle. When the plates are stacked, the holes line up to make the cavity for the lock.","inputs":["sheet-steel"]},{"name":"Stack and rivet","process":"assemble","text":"Workers collect the plates in order and rivet them together. Those rivets must clamp hard without squeezing the bores out of shape.","inputs":[]},{"name":"Electroplate the body","process":"coat","text":"The whole riveted casing goes into a plating bath, which puts on a metal skin against rust. Plating the casing as one piece saves doing every plate singly.","inputs":["copper","tin"]},{"name":"Bend and harden the shackle","process":"heat-treat","text":"Steel rod is bent into a U and heat-treated until it is hard enough to resist bolt cutters and saws.","inputs":["steel"]},{"name":"Make the lock cylinder","process":"machine","text":"Brass bar is machined into a cylinder with holes for pins and springs, and the keyway is cut.","inputs":["brass"]},{"name":"Fit the mechanism","process":"assemble","text":"Pins and springs are loaded into the cylinder, which is slid into the cavity, and the shackle is latched into place.","inputs":["coil-spring"]},{"name":"Cycle the key","process":"inspect","text":"The key is turned to check that the lock engages and releases.","inputs":[]}],"facts":["Padlocks have been used in China since the late Eastern Han dynasty, 25 to 220 AD.","A padlock with spring tines, dated to 850 AD, was found at the Jorvik Viking settlement in York, England.","Harry Soref started Master Lock in the early 1920s with the first laminated padlock."],"where":[],"whereNote":null,"sources":[{"title":"Padlock","url":"https://en.wikipedia.org/wiki/Padlock"},{"title":"Stamping (metalworking)","url":"https://en.wikipedia.org/wiki/Stamping_(metalworking)"},{"title":"Laminated padlock (US4899560)","url":"https://patents.google.com/patent/US4899560"},{"title":"Laminated padlock (US4098100)","url":"https://patents.google.com/patent/US4098100A"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"paint","name":"Paint","kind":"product","category":"chemicals","title":"How paint is made","url":"https://assemblyline.org/make/paint","stations":6,"upstream":60,"downstream":45,"depth":9,"dek":"Latex wall paint is white pigment and plastic glue floated in water, and it sets as the water leaves.","answer":"Water-based paint starts with a mill-base: water, glycol, dispersants and defoamer premixed for five minutes, then loaded with titanium dioxide and extenders under a high-speed blade. Meanwhile resin is stirred with thickener in a larger let-down vat for about 30 minutes. The mill-base is pumped in, the batch is adjusted against lab tests, and it goes to cans.","aka":["latex paint","house paint","emulsion paint"],"inputs":["water","titanium-dioxide","pigment","acrylic","tin-can"],"uses":["refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","scissors","mirror","car","electric-car","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","golf-ball","wallpaper","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame"],"grounds":["water","titanium-ore","iron-ore","sulfur","rock-salt","coal","air","crude-oil","natural-gas","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","limestone","dolomite","manganese-ore","quartz","timber","sugar-beet"],"upstreamSlugs":["water","titanium-dioxide","pigment","acrylic","tin-can","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","carbon-black","sulfur","propylene","ammonia","methanol","tinplate","lacquer","ink","rock-salt","coal","air","crude-oil","naphtha","natural-gas","steel","tin","ethanol","vegetable-oil","phenolic-resin","hydrogen","pig-iron","magnesium","steel-scrap","lime","manganese","argon","tin-ore","corn","sugarcane","yeast","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","limestone","dolomite","silicon","propane","manganese-ore","molasses","benzene","quartz","charcoal","timber","sugar-beet","toluene"],"downstreamSlugs":["refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","scissors","mirror","car","electric-car","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","golf-ball","wallpaper","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","padlock"],"steps":[{"name":"Premix the liquids","process":"mix","text":"Water, propylene glycol, surfactants, dispersants, defoamer and biocide are measured into a dispersion vat and stirred for about five minutes. This is the start of the mill-base.","inputs":["water"]},{"name":"Load and disperse pigment","process":"grind","text":"With the disperser running, titanium dioxide and extenders such as calcite, talc and barytes go in a set order. Blade speed climbs as the load grows, and shear breaks clumps of pigment so resin and additives can wet every particle.","inputs":["titanium-dioxide","pigment"]},{"name":"Prepare the let-down","process":"mix","text":"In a larger vat, the emulsion resin is mixed with defoamer, thickener and coalescent solvent for about 30 minutes. The resin is the part that later forms the film.","inputs":["acrylic"]},{"name":"Pump in the mill-base","process":"mix","text":"The finished mill-base flows into the let-down while hydraulic mixers keep everything moving. The nearly complete paint is stirred for another 30 minutes before the last thickeners and additives go in.","inputs":[]},{"name":"Test and adjust","process":"inspect","text":"The lab samples the batch for viscosity, density, hiding power, gloss and dry time. The batch may be fine tuned and mixed again, and tinted lines also get checked for color strength.","inputs":[]},{"name":"Fill the cans","process":"fill","text":"Approved batches go to canning. Two samples are taken here: one kept in case it is needed later, and one for final inspection.","inputs":["tin-can"]}],"facts":["Interior walls at the Ness of Brodgar, which are 5,000 years old, include stones painted in yellows, reds and oranges using ochre pigment.","In 1718 an English inventor patented a machine for grinding colors and claimed that paint ground in his horse-driven mill went more than twice as far as paint ground any other way."],"where":[],"whereNote":null,"sources":[{"title":"Resene: What is paint and how is it made?","url":"https://www.resene.co.nz/whatispaint.htm"},{"title":"Paint","url":"https://en.wikipedia.org/wiki/Paint"},{"title":"Titanium dioxide","url":"https://en.wikipedia.org/wiki/Titanium_dioxide"},{"title":"Latex paint","url":"https://en.wikipedia.org/wiki/Latex_paint"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"palm-oil","name":"Palm oil","kind":"material","category":"food","title":"How palm oil is made","url":"https://assemblyline.org/make/palm-oil","stations":8,"upstream":2,"downstream":14,"depth":1,"dek":"Palm oil comes from the orange pulp around the nut, and the kernel inside is pressed separately into a different oil.","answer":"Fresh fruit bunches are trucked to a mill and steamed, which stops the enzymes that spoil the oil. A rotating drum knocks the fruit off the stalks, stirred digesters mash it, and a screw press squeezes out liquor. Diluted liquor settles in tanks at 90 to 95 °C, and the skimmed oil is spun and vacuum dried into crude palm oil. Nuts left in the press cake are cracked for their kernels, which are pressed elsewhere.","aka":["crude palm oil","palm kernel oil","RBD palm oil"],"inputs":["oil-palm-fruit","water"],"uses":["soap","glycerin","margarine","instant-noodles","sandwich-cookie","popcorn","hazelnut-spread","toffee"],"grounds":["oil-palm-fruit","water"],"upstreamSlugs":["oil-palm-fruit","water"],"downstreamSlugs":["soap","glycerin","margarine","instant-noodles","sandwich-cookie","popcorn","hazelnut-spread","toffee","toothpaste","sunscreen","chewing-gum","snow-globe","cough-syrup","gelatin-capsule"],"steps":[{"name":"Cut and haul the bunches","process":"harvest","text":"Fresh fruit bunches are cut in the plantation and trucked to the mill, where they are received and loaded for steaming.","inputs":["oil-palm-fruit"]},{"name":"Steam the bunches","process":"cook","text":"Horizontal, vertical or continuous sterilizers steam the bunches, halting the enzymes and loosening the fruit. Condensate drains off as a waste stream.","inputs":[]},{"name":"Thresh off the fruit","process":"separate","text":"Bunches tumble through a horizontal drum turning about 22 times a minute. Fruit falls through bars, often after a second stage, and the empty stalks leave for mulch or fuel.","inputs":[]},{"name":"Mash in the digester","process":"mix","text":"Vertical digesters heat the fruit with steam while stirring arms mash it for about 30 minutes, loosening flesh from nuts and breaking open oil cells.","inputs":[]},{"name":"Screw press the mash","process":"press","text":"A continuous screw press squeezes out oily liquor and leaves a cake of fibers and nuts. Double screws get more oil and break fewer nuts.","inputs":[]},{"name":"Dilute and settle","process":"separate","text":"The liquor is thinned with water, screened of coarse dirt and held in a vertical tank at 90 to 95 °C. Oil rises and is skimmed off the top.","inputs":["water"]},{"name":"Purify and dry","process":"refine","text":"A high-speed centrifuge removes remaining impurities and a vacuum dryer pulls out moisture. The crude oil is then pumped to storage for the refinery.","inputs":[]},{"name":"Crack out the kernels","process":"crush","text":"Nuts recovered from the press cake are cracked and the kernels separated. They go on to make a separate kernel oil.","inputs":[]}],"facts":["Red palm oil gets its intense orange color from a high content of carotenoids.","Palm oil is much more efficient than other oils in land and water use, yet the deforestation it drives causes greater biodiversity loss than switching oils would."],"where":[{"place":"Indonesia","share":"44 million tonnes"},{"place":"Malaysia","share":"19.7 million tonnes"}],"whereNote":"2023 to 2024 production; the world total was 77.3 million tonnes.","sources":[{"title":"IntechOpen: Palm oil milling operations and sustainable technologies","url":"https://www.intechopen.com/chapters/88739"},{"title":"Palm oil","url":"https://en.wikipedia.org/wiki/Palm_oil"},{"title":"Vegetable oil","url":"https://en.wikipedia.org/wiki/Vegetable_oil"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"paper","name":"Paper","kind":"material","category":"wood-paper","title":"How paper is made","url":"https://assemblyline.org/make/paper","stations":7,"upstream":13,"downstream":30,"depth":4,"dek":"A paper machine starts with a slurry that is under 0.4 percent fiber, and a roll of paper comes out the far end.","answer":"Paper is a mat of cellulose fibers drained from water. Pulp is diluted into a thin slurry, sprayed across a fast-moving mesh screen so the water drains away, pressed between rollers, then dried over steam-heated cylinders. A final smoothing squeeze finishes the sheet, and it is wound onto a reel weighing several tons.","aka":["writing paper","printer paper","sheet paper"],"inputs":["wood-pulp","water","kaolin","limestone"],"uses":["soap","adhesive-bandage","aa-battery","vacuum-cleaner","drywall","popcorn","crayon","fireworks","plastic-straw","paper-straw","paper-cup","paper-bag","pizza-box","egg-carton","wallpaper","laminate-floor","board-game","jigsaw-puzzle","tampon","sanitary-pad","cotton-swab","loudspeaker","vinyl-record","compact-disc","inkjet-printer","newspaper","book","envelope","sticky-notes","playing-cards"],"grounds":["water","kaolin","limestone","timber","rock-salt","air","natural-gas"],"upstreamSlugs":["wood-pulp","water","kaolin","limestone","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","rock-salt","air","hydrogen","natural-gas"],"downstreamSlugs":["soap","adhesive-bandage","aa-battery","vacuum-cleaner","drywall","popcorn","crayon","fireworks","plastic-straw","paper-straw","paper-cup","paper-bag","pizza-box","egg-carton","wallpaper","laminate-floor","board-game","jigsaw-puzzle","tampon","sanitary-pad","cotton-swab","loudspeaker","vinyl-record","compact-disc","inkjet-printer","newspaper","book","envelope","sticky-notes","playing-cards"],"steps":[{"name":"Thin the stock","process":"mix","text":"Pulp is blended in the right ratio of hardwood, softwood or recycled fiber and diluted in tanks. Mills mix in whitening agents, fillers and chemicals that give the sheet strength or water resistance.","inputs":["wood-pulp","water","kaolin"]},{"name":"Beat the fibers","process":"grind","text":"The slurry passes through a refiner that roughs up the surface of each fiber, which lets the fibers grab each other when the sheet forms.","inputs":[]},{"name":"Spray onto the wire","process":"cast","text":"A headbox spreads the slurry across the full width of a fast-moving woven mesh. Less than 0.4 percent of what sprays out is fiber, and the rest is water, which drains through the mesh or is sucked out by vacuum boxes.","inputs":[],"spec":"under 0.4% fiber"},{"name":"Squeeze between rolls","process":"press","text":"The wet sheet is carried on felts through the nips of heavy rolls that wring out more water. Leaving the press, the web is still more than half water.","inputs":[]},{"name":"Dry over hot cylinders","process":"dry","text":"The sheet snakes around a long row of steam-heated cylinders that boil off the remaining water. It comes out with only about 6 percent water, the level it will keep in a room.","inputs":[],"spec":"about 6% water"},{"name":"Size and smooth","process":"coat","text":"A thin layer of starch can be rolled on to cut dust and improve how ink sits. Stacks of rolls called calenders then squeeze the sheet to make it smooth and even in thickness. Glossy grades get a coating of kaolin clay or calcium carbonate.","inputs":["kaolin","limestone"]},{"name":"Wind and slit","process":"cut","text":"The finished sheet is wound onto a giant reel, then unrolled and slit into narrower rolls or chopped into sheets of standard sizes like A4 and letter.","inputs":[]}],"facts":["Louis-Nicolas Robert of France patented the first continuous paper-making machine in 1799.","Papermakers used pulped rags for nearly 2,000 years until wood pulp took over after 1844.","Printing and writing paper usually weighs between 60 and 120 grams per square meter, and anything heavier than 160 is considered card."],"where":[],"whereNote":null,"sources":[{"title":"Papermaking","url":"https://en.wikipedia.org/wiki/Papermaking"},{"title":"Paper machine","url":"https://en.wikipedia.org/wiki/Paper_machine"},{"title":"Paper","url":"https://en.wikipedia.org/wiki/Paper"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"paper-bag","name":"Paper bag","kind":"product","category":"wood-paper","title":"How paper bags are made","url":"https://assemblyline.org/make/paper-bag","stations":6,"upstream":35,"downstream":0,"depth":8,"dek":"A paper bag is a roll of kraft paper folded into a tube and cut so fast that a machine can finish more than two a second.","answer":"A paper bag machine unwinds a big roll of kraft paper, folds and glues it into a long flat tube, then cuts the tube to bag length. The bottom is creased, glued and folded to a base, and handles are glued on if the bag needs them. One line can turn out well over a hundred bags a minute.","aka":["kraft bag","shopping bag","grocery bag"],"inputs":["paper","adhesive"],"uses":[],"grounds":["water","kaolin","limestone","timber","crude-oil","rock-salt","air","natural-gas","sulfur","coal"],"upstreamSlugs":["paper","adhesive","wood-pulp","water","kaolin","limestone","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","hydrogen","rock-salt","air","naphtha","natural-gas","sulfur","benzene","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Unroll the paper","process":"assemble","text":"A reel of kraft paper, strong paper pulped from softwood, feeds into the machine. Printed rolls arrive pre-patterned.","inputs":["paper"]},{"name":"Glue on the handles","process":"laminate","text":"On carrier bags, a separate unit cuts handle strips or twists paper rope, glues them, and presses them onto the edge of the moving paper.","inputs":["adhesive"]},{"name":"Fold and paste a tube","process":"assemble","text":"The ribbon of paper is folded around so its edges overlap and are pasted, giving a continuous flat tube.","inputs":["adhesive"]},{"name":"Cut the tube to length","process":"cut","text":"A knife slices the tube into sections the height of a bag, with the cut timed to the printing.","inputs":[]},{"name":"Crease and glue the base","process":"assemble","text":"The end of each section is creased and glue is applied. The base folds into a flat, square-bottomed shape and is pressed shut.","inputs":["adhesive"]},{"name":"Stack and pack","process":"package","text":"Finished bags are counted into stacks, and a camera or an operator checks for defects.","inputs":[]}],"facts":["The first machine to mass-produce paper bags was invented in 1852 by Francis Wolle, a Pennsylvania schoolteacher.","Sack kraft paper is made on purpose to be porous, so air escapes quickly while powder is poured in, letting a 25 kg sack fill in about 3.5 seconds.","Charles Stilwell's 1883 bag with pleated sides was called the S.O.S., short for Self-Opening Sack."],"where":[],"whereNote":null,"sources":[{"title":"Paper bag","url":"https://en.wikipedia.org/wiki/Paper_bag"},{"title":"Fully Automatic Paper Bag Machine With Twisted Rope and Flat Handle Inline Machine","url":"https://www.nesscoindia.com/ad/en/products/paper-bag-machine/ns-fpbmtf"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"paper-cup","name":"Paper cup","kind":"product","category":"wood-paper","title":"How paper cups are made","url":"https://assemblyline.org/make/paper-cup","stations":7,"upstream":47,"downstream":0,"depth":8,"dek":"A paper cup is a plastic-lined paperboard wall wrapped around a bottom disc that was pressed into a shallow dish.","answer":"Cup board is paperboard with a waterproof coating, usually polyethylene. A machine cuts a curved wall blank and a round bottom blank. The bottom is pressed into a shallow tray with an upturned lip, the wall is wrapped around a rod, its seam is heated shut, and the wall edge is folded over the lip and sealed.","aka":["disposable cup","coffee cup"],"inputs":["paper","polyethylene","ink"],"uses":[],"grounds":["water","kaolin","limestone","timber","natural-gas","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","coal","sugar-beet"],"upstreamSlugs":["paper","polyethylene","ink","wood-pulp","water","kaolin","limestone","ethylene","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","naphtha","natural-gas","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","rock-salt","hydrogen","benzene","propylene","methanol","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Coat the cup board","process":"coat","text":"Paper is made on a multi-ply machine into stiff board and given a waterproof layer so hot or cold drinks cannot soak through. Polyethylene replaced the old clay and wax coatings.","inputs":["paper","polyethylene"]},{"name":"Print the pattern","process":"print","text":"Designs are printed on the board in long runs using flexographic plates, one for each color.","inputs":["ink"]},{"name":"Die-cut the blanks","process":"cut","text":"One cutter punches out the curved wall blank, shaped like a fan segment. A second cutter punches a plain circle for the bottom.","inputs":[]},{"name":"Press the bottom lip","process":"stamp","text":"The circle is pushed through an opening smaller than itself, so its outer edge bends down into a lip. Cup makers work hard to avoid pleats in this lip, because pleats can leak.","inputs":[]},{"name":"Wrap the wall seam","process":"weld","text":"The wall blank wraps around a rod that carries the bottom. The overlapping edges are heated and squeezed together so the plastic coating fuses them.","inputs":[]},{"name":"Fold and seal the base","process":"assemble","text":"The bottom of the wall is folded over the lip and pressed against it, sandwiching the lip and sealing the base.","inputs":[]},{"name":"Roll the rim","process":"mold","text":"The top edge is curled outward into a rolled rim, which makes the cup stiffer and easier to drink from.","inputs":[]}],"facts":["The Dixie Cup was first called the Health Kup, and was renamed in 1919 after a line of dolls.","Early cups for hot drinks were made watertight by dropping clay into the bottom and spinning the cup at high speed, but the drinks tasted of cardboard.","Because cups are lined with plastic, they are hard to recycle with ordinary paper."],"where":[],"whereNote":null,"sources":[{"title":"Paper cup","url":"https://en.wikipedia.org/wiki/Paper_cup"},{"title":"Paper cup bottoms and methods and apparatus for forming same","url":"https://patents.google.com/patent/US6264100"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"paper-straw","name":"Paper straw","kind":"product","category":"wood-paper","title":"How paper straws are made","url":"https://assemblyline.org/make/paper-straw","stations":6,"upstream":35,"downstream":0,"depth":8,"dek":"A paper straw is a long ribbon of paper wound around a rod like a candy stripe, with glue in every seam.","answer":"Reels of food-grade paper feed into a machine that coats them with water-based glue and winds them around a mandrel in a spiral. The stripes of paper overlap and stick, forming a hollow tube. Rotary blades cut the tube into lengths, and the straws are dried and collected on a conveyor.","aka":["eco straw","biodegradable straw"],"inputs":["paper","adhesive"],"uses":[],"grounds":["water","kaolin","limestone","timber","crude-oil","rock-salt","air","natural-gas","sulfur","coal"],"upstreamSlugs":["paper","adhesive","wood-pulp","water","kaolin","limestone","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","hydrogen","rock-salt","air","naphtha","natural-gas","sulfur","benzene","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Feed the paper reels","process":"assemble","text":"Several reels of food-grade kraft paper unwind together. Two, three or four layers go in at once, depending on how stiff the straw needs to be.","inputs":["paper"],"spec":"paper weight 60 to 120 gsm"},{"name":"Glue the layers","process":"laminate","text":"A water-based adhesive goes between the layers just before they meet, so they bond as they are wound together.","inputs":["adhesive"]},{"name":"Spiral-wind a tube","process":"assemble","text":"The glued ribbons wrap around a fixed rod at an angle, each turn overlapping the last. The result is a continuous hollow tube with a spiral seam.","inputs":[]},{"name":"Dry the glue","process":"dry","text":"Some machines rely on the winding itself to set the glue. Others pass the tube through a warm oven so the seam sets firm before it is cut.","inputs":[]},{"name":"Cut to length","process":"cut","text":"Rotary blades slice the moving tube into straws of uniform length.","inputs":[]},{"name":"Collect and pack","process":"package","text":"A conveyor carries the finished straws away for counting and packing.","inputs":[]}],"facts":["Marvin C. Stone patented the modern drinking straw in 1888 after finding that rye stalks made his mint julep taste like grass. He wound paper around a pencil to make his first one.","Older paper straws were coated in wax, but still went soggy."],"where":[],"whereNote":null,"sources":[{"title":"Paper Straw Machine","url":"https://www.nesscoindia.com/cc/en/products/paper-straw-machine/ns-ps9"},{"title":"Drinking straw","url":"https://en.wikipedia.org/wiki/Drinking_straw"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"paperclip","name":"Paperclip","kind":"product","category":"hardware","title":"How paperclips are made","url":"https://assemblyline.org/make/paperclip","stations":5,"upstream":68,"downstream":0,"depth":10,"dek":"The classic clip is one bent wire, folded one and a half times, and it was never patented.","answer":"Clip machines feed coiled steel wire through straightening rollers and a cutter, then bend it around dies. In one patented design, cut wires are held by magnets on a moving belt and handed to a turning set of forming dies, where rams bend each piece three times. Finished clips drop out and a counter sends a set number to each box.","aka":["paper clip","gem clip"],"inputs":["steel-wire","cardboard-box"],"uses":[],"grounds":["water","iron-ore","limestone","air","dolomite","manganese-ore","natural-gas","timber","soybeans","rapeseed","clay","crude-oil","titanium-ore","sulfur","corn","sugarcane","coal","quartz","rock-salt","sugar-beet"],"upstreamSlugs":["steel-wire","cardboard-box","steel","cardboard","ink","adhesive","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","wood-pulp","water","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","iron-ore","coke","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","timber","caustic-soda","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","titanium-ore","chlorine","sulfur","corn","sugarcane","yeast","ethylene","propylene","ammonia","methanol","acetone","nitric-acid","hydrogen","coal","quartz","charcoal","rock-salt","benzene","molasses","naphtha","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Straighten the coil","process":"draw","text":"Wire comes off a coil with a curve in it. Rollers take out the bend before any forming starts, since tension or curl in the wire makes the clip's size hard to control.","inputs":["steel-wire"]},{"name":"Snip each length","process":"cut","text":"A cutter severs a length for one clip. In one patented Gem machine, the blade first cuts only partway so the wire stays gripped while the first loops form, then finishes the cut.","inputs":[]},{"name":"Line up on magnets","process":"assemble","text":"In a higher-speed patented design, cut pieces land on a belt fitted with magnets at regular intervals. A chain and toothed wheels pass them along, and a second set of magnets hands each one to the forming station facing the right way.","inputs":[]},{"name":"Bend the loops","process":"stamp","text":"Rams push the wire around segmented rings on three turning annular dies, or around spindles in older machines. Each station adds a bend until the flat double loop is complete. Several clips form per cycle in the newer design, where earlier machines made one at a time.","inputs":[]},{"name":"Count into boxes","process":"package","text":"The finished clips fall out of the dies. A counter on the machine deposits a set number into each box before it is closed.","inputs":["cardboard-box"]}],"facts":["A regular metal paper clip weighs about a gram.","The Gem design, the most common clip still in use, was never patented.","Johan Vaaler of Norway, often credited as the inventor, patented a clip that lacked the second full loop and was harder to use."],"where":[],"whereNote":null,"sources":[{"title":"US4434818A: Wire feeding and wire forming device for paper clip making machine","url":"https://patents.google.com/patent/US4434818"},{"title":"US2297156A: Machine for making Gem paper clips","url":"https://patents.google.com/patent/US2297156"},{"title":"Paper clip","url":"https://en.wikipedia.org/wiki/Paper_clip"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"p-xylene","name":"Para-xylene","kind":"material","category":"chemicals","title":"How para-xylene is made","url":"https://assemblyline.org/make/p-xylene","stations":5,"upstream":5,"downstream":111,"depth":3,"dek":"Para-xylene is the chemical backbone of polyester bottles. About 37 million tons were wanted in 2014.","answer":"Para-xylene is produced by catalytic reforming of petroleum naphtha, which creates a mix of benzene, toluene and xylene isomers. Plants then separate para-xylene from its look-alikes by distillation, adsorption or crystallization. Nearly all of it goes on to become terephthalic acid for polyester and PET.","aka":["p-xylene","1,4-dimethylbenzene","PX"],"inputs":["naphtha"],"uses":["pet-plastic","kevlar"],"grounds":["crude-oil","water","natural-gas"],"upstreamSlugs":["naphtha","crude-oil","water","hydrogen","natural-gas"],"downstreamSlugs":["pet-plastic","kevlar","polyester","plastic-bottle","credit-card","3d-printer-filament","drum-kit","bottled-water","brake-pad","canoe","tire","soccer-ball","marker-pen","highlighter","sofa","office-chair","pillow","garden-hose","volleyball","kite","kitchen-sponge","wet-wipes","seat-belt","sailboat","hoodie","leggings","swimsuit","raincoat","backpack","suitcase","shoelace","curtain","flag","wireless-earbuds","microphone","sneaker","mattress","umbrella","zipper","button","thread","teddy-bear","shampoo","sunscreen","aspirin","detergent","bleach","vitamin-c","ketchup","cola","sparkling-water","soda","dish-soap","hair-dye","foundation-makeup","mouthwash","cough-syrup","car","electric-car","bicycle","motorcycle","down-jacket","handbag","jeans","dress-shirt","suit","baseball-cap","airbag","baseball","fireworks","bike-helmet","candle","ice-skates","fishing-rod","football","yo-yo","fashion-doll","tampon","silk-tie","underwear","winter-gloves","leather-belt","wallet","hiking-boots","high-heels","felt-hat","blanket","book","t-shirt","socks","sweater","leather-shoe","towel","flour","bread","instant-noodles","tortilla","croissant","donut","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","fish-sticks","modeling-clay","licorice","cake-mix"],"steps":[{"name":"Reform the naphtha","process":"react","text":"Catalytic reforming turns naphtha into a stream rich in aromatic compounds. This stream is called reformate.","inputs":["naphtha"]},{"name":"Extract the BTX group","process":"refine","text":"Benzene, toluene and the xylene isomers are pulled out of the reformate together. The three xylenes boil so close to each other that plain distillation cannot finish the job.","inputs":[]},{"name":"Isolate the para isomer","process":"separate","text":"A series of distillation, adsorption or crystallization steps separates para-xylene from ortho and meta. These separations are major cost factors in the process.","inputs":[]},{"name":"Convert the leftover isomers","process":"react","text":"Isomers that are not para-xylene are reacted over catalysts to make more of it, and sent back through the separation. The loop wastes little.","inputs":[]},{"name":"Ship to polyester plants","process":"fill","text":"Para-xylene is stored and sent to plants that turn it into terephthalic acid. That acid is the raw material for polyester and PET.","inputs":[]}],"facts":["Annual demand for para-xylene was estimated at 37 million tons in 2014 and still rising.","It is one of three xylene isomers that differ only in where two methyl groups sit on the ring.","Para-xylene is also the starting point for parylene, a plastic used as a thin protective coating."],"where":[],"whereNote":null,"sources":[{"title":"Para-xylene","url":"https://en.wikipedia.org/wiki/Para-xylene"},{"title":"Purified terephthalic acid","url":"https://en.wikipedia.org/wiki/Purified_terephthalic_acid"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"paraffin-wax","name":"Paraffin wax","kind":"material","category":"chemicals","title":"How paraffin wax is made","url":"https://assemblyline.org/make/paraffin-wax","stations":6,"upstream":4,"downstream":148,"depth":2,"dek":"Paraffin is the waxy sludge that clogs lubricating oil in the cold, filtered out and refined into candle wax.","answer":"Paraffin wax is a byproduct of making lubricating oil. A heavy cut from crude oil is chilled so that the waxy part crystallizes, and filters strain it out. The crude wax, called slack wax, is de-oiled and treated with hydrogen to remove color and odor, then cast into slabs or sold as liquid.","aka":["candle wax","petroleum wax","paraffin"],"inputs":["crude-oil","hydrogen"],"uses":["deodorant","sunscreen","lipstick","mascara","adhesive","pencil","chewing-gum","turbine-blade","crayon","candle","cork-stopper","printer-toner","golf-club","eyeshadow","dental-floss","mdf","match"],"grounds":["crude-oil","natural-gas","water"],"upstreamSlugs":["crude-oil","hydrogen","natural-gas","water"],"downstreamSlugs":["deodorant","sunscreen","lipstick","mascara","adhesive","pencil","chewing-gum","turbine-blade","crayon","candle","cork-stopper","printer-toner","golf-club","eyeshadow","dental-floss","mdf","match","adhesive-bandage","credit-card","duct-tape","led-bulb","ev-battery","nail","insulation","popcorn","windshield","skateboard","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","pencil-eraser","clear-tape","staple","sofa","ski","snowboard","ice-skates","fishing-rod","volleyball","cricket-bat","dartboard","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","globe","snow-globe","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","brake-pad","sailboat","dress-shirt","suit","raincoat","handbag","suitcase","wallet","flip-flops","hiking-boots","high-heels","smartwatch","wireless-earbuds","loudspeaker","microphone","camera-lens","e-reader","plywood","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","sneaker","leather-shoe","baseball-cap","carpet","mattress","diaper","jet-engine","champagne","treadmill","electric-car","dishwasher","car","aluminum-window-frame","digital-camera","shipping-container","ceiling-fan","toothbrush","fireworks","plastic-wrap","trading-cards","cake-mix","soda","energy-drink","hair-dye","tampon","soap","toothpaste","detergent","plastic-bag","nitrile-glove","washing-machine","vacuum-cleaner","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","salsa","canned-meat","fish-sticks","zip-bag","blender","pillow","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","game-console","wifi-router","remote-control","facial-tissue","airplane","aa-battery","candy-cane","syringe"],"steps":[{"name":"Draw a heavy oil cut","process":"refine","text":"Vacuum distillation of crude oil yields heavy lubricating oil fractions. These fractions are rich in long, straight hydrocarbons that turn solid in the cold.","inputs":["crude-oil"]},{"name":"Chill until wax crystallizes","process":"chill","text":"The oil is mixed with a solvent and cooled until the wax forms crystals. The remaining oil stays liquid and flows freely.","inputs":[]},{"name":"Filter out the wax","process":"separate","text":"Rotating drum filters strain the crystals from the cold oil. What stays on the filter is slack wax, a greasy, oily solid.","inputs":[]},{"name":"Sweat out the oil","process":"refine","text":"Slack wax is warmed slowly or washed with solvent so the remaining oil drains away. This leaves a harder, drier wax with a higher melting point.","inputs":[]},{"name":"Hydrotreat it clean","process":"react","text":"The wax is treated with hydrogen over a catalyst to remove color, smell and reactive compounds. The wax comes out white and nearly odorless.","inputs":["hydrogen"]},{"name":"Cast into slabs","process":"cast","text":"Liquid wax is poured into molds or onto a cooling belt and cut into slabs. Candle, crayon and packaging makers buy it by the pallet.","inputs":[]}],"facts":["Carl Reichenbach first made paraffin wax in Germany in 1830, and it burned more cleanly and reliably than tallow candles.","Paraffin wax is a mix of hydrocarbons with 20 to 40 carbon atoms, and it begins to melt above approximately 37 °C.","Paraffin phase-change cooling was used for the electronics of the Lunar Roving Vehicle in the early 1970s."],"where":[],"whereNote":null,"sources":[{"title":"Paraffin wax","url":"https://en.wikipedia.org/wiki/Paraffin_wax"},{"title":"Oil refinery","url":"https://en.wikipedia.org/wiki/Oil_refinery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"parmesan","name":"Parmesan","kind":"product","category":"food","title":"How Parmesan is made","url":"https://assemblyline.org/make/parmesan","stations":8,"upstream":4,"downstream":0,"depth":2,"dek":"Every wheel of real Parmigiano Reggiano is tapped with a tiny hammer to listen for cracks inside.","answer":"Raw cow's milk goes into copper-lined vats with a whey starter and calf rennet. The curd is cut to rice-sized grains, cooked hot, and lifted out in muslin to be split into two wheels. After weeks in brine, the wheels age on wooden shelves for at least a year before inspectors test each one.","aka":["Parmigiano Reggiano","parmigiano"],"inputs":["raw-milk","table-salt"],"uses":[],"grounds":["raw-milk","rock-salt","seawater"],"upstreamSlugs":["raw-milk","table-salt","rock-salt","seawater"],"downstreamSlugs":[],"steps":[{"name":"Mix last night with this morning","process":"mix","text":"Whole milk from the morning milking is blended with naturally skimmed milk from the evening before. The result is a part-skim mixture, and it is not pasteurized.","inputs":["raw-milk"]},{"name":"Warm it in copper vats","process":"cook","text":"The milk is pumped into copper-lined vats, which heat evenly and add copper ions to the mix. Starter whey carrying heat-loving bacteria goes in, and the milk is brought up to a gentle warmth.","inputs":[],"spec":"33 to 35 °C"},{"name":"Set and shatter the curd","process":"cut","text":"Calf rennet turns the milk to a gel in a few minutes. Machines then break the gel into pieces about the size of rice grains.","inputs":[],"spec":"10 to 12 minutes to set"},{"name":"Cook the grains hot","process":"cook","text":"The cheesemaker raises the temperature with great care, then lets the grains settle to the bottom of the vat as a single mass.","inputs":[],"spec":"55 °C, settle 45 to 60 minutes"},{"name":"Lift out two wheels","process":"mold","text":"The settled curd is gathered in muslin, cut in two and dropped into molds. Each vat holds 1,100 liters of milk and yields two wheels, each starting at about 45 kilograms of curd. A belt pressed around each wheel stamps in the dairy number and date.","inputs":[]},{"name":"Float in salt brine","process":"dry","text":"Wheels sit in tanks of brine saturated almost to the limit with salt. Salt is the only seasoning, and the wheels soak it up slowly.","inputs":["table-salt"],"spec":"20 to 25 days"},{"name":"Age on wooden shelves","process":"dry","text":"Wheels move to aging rooms with shelves stacked 24 high. Every seven days each wheel and its shelf are cleaned and the wheel is turned.","inputs":[],"spec":"at least 12 months"},{"name":"Tap every wheel","process":"inspect","text":"At 12 months a trained grader taps each wheel with a small hammer and listens for hidden cracks and voids. The sound sorts wheels into three grades, and only the top grade gets the official brand.","inputs":[]}],"facts":["Parmigiano Reggiano uses about 18 percent of all the milk produced in Italy.","Some Italian banks accept wheels of Parmesan as collateral for a loan.","Between November 2013 and January 2015 a gang stole 2,039 wheels from warehouses in northern and central Italy.","In the European Union only the Italian cheese may legally be called Parmesan."],"where":[],"whereNote":null,"sources":[{"title":"Parmigiano-Reggiano","url":"https://en.wikipedia.org/wiki/Parmigiano-Reggiano"},{"title":"Cheese","url":"https://en.wikipedia.org/wiki/Cheese"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pasta","name":"Pasta","kind":"product","category":"food","title":"How dried pasta is made","url":"https://assemblyline.org/make/pasta","stations":7,"upstream":3,"downstream":0,"depth":2,"dek":"Dried pasta is a dough of just semolina and water, pressed through a die, then dried slowly.","answer":"A pasta factory mixes semolina from durum wheat with water into a crumbly dough, then kneads and forces it through a die under pressure. The die decides the shape. Cutters slice the strands or tubes to length, and long dryers remove the water at low temperature. Dried pasta keeps for years.","aka":["dried pasta","spaghetti","macaroni","noodles"],"inputs":["durum-wheat","semolina","water"],"uses":[],"grounds":["durum-wheat","water"],"upstreamSlugs":["durum-wheat","semolina","water"],"downstreamSlugs":[],"steps":[{"name":"Mill the durum into semolina","process":"crush","text":"Hard durum wheat is milled to coarse, golden granules called semolina, rather than fine flour. The bran is sifted out, and vitamins and minerals lost in milling may be added back.","inputs":["durum-wheat"]},{"name":"Hydrate into a stiff dough","process":"mix","text":"Semolina and water are mixed in a vacuum chamber into a crumbly mass like damp sand. Eggs can be added for richness but are not required.","inputs":["semolina","water"]},{"name":"Knead and push through a die","process":"extrude","text":"A screw presses and kneads the dough into one mass and forces it through a die. Holes in the die can be round for spaghetti, shaped for macaroni or formed with inserts for fusilli. Most dried pasta is made by extrusion.","inputs":[]},{"name":"Cut to length","process":"cut","text":"A rotating knife slices short shapes right at the die face. Long strands are hung over rods and cut to size later.","inputs":[]},{"name":"Pre-dry the surface","process":"dry","text":"Warm air blows over the fresh pasta so its outside sets. This stops the pieces from sticking to each other or sagging.","inputs":[]},{"name":"Dry slowly in a long chamber","process":"dry","text":"Pasta needs low-temperature drying for several hours in humidity-controlled chambers. Drying too fast leaves cracks that cause it to break in the pot.","inputs":[]},{"name":"Cool, pack and ship","process":"package","text":"The brittle pasta is cooled, weighed and boxed or bagged. Dried pasta can be shipped far and has a long shelf life.","inputs":[]}],"facts":["There are 310 specific pasta forms known by over 1,300 documented names.","A license for the first pasta factory was issued in Venice in 1740.","Pasta dough kept in a drying chamber too fast cracks, so factories dry it slowly for hours at low temperature."],"where":[],"whereNote":null,"sources":[{"title":"Pasta","url":"https://en.wikipedia.org/wiki/Pasta"},{"title":"Flour","url":"https://en.wikipedia.org/wiki/Flour"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pasteurized-milk","name":"Pasteurized milk","kind":"product","category":"food","title":"How pasteurized milk is made","url":"https://assemblyline.org/make/pasteurized-milk","stations":6,"upstream":1,"downstream":8,"depth":1,"dek":"Milk is flash-heated for 15 seconds and chilled again, killing disease germs and not the taste.","answer":"Raw milk is cooled on the farm and trucked to a dairy. There a centrifuge separates the cream, which is added back to set the fat level. Then the milk is homogenized and pasteurized, usually at 72 °C for 15 seconds, cooled fast and bottled. Kept cold, it stays fresh for up to three weeks.","aka":["milk","homogenized milk","UHT milk","skim milk"],"inputs":["raw-milk"],"uses":["cheese","yogurt","ice-cream","croissant","mozzarella","cheddar","caramel"],"grounds":["raw-milk"],"upstreamSlugs":["raw-milk"],"downstreamSlugs":["cheese","yogurt","ice-cream","croissant","mozzarella","cheddar","caramel","frozen-pizza"],"steps":[{"name":"Milk and chill on the farm","process":"harvest","text":"Cows are milked by machine and the milk goes straight into a cooled tank. Cold slows the bacteria that would sour it.","inputs":["raw-milk"]},{"name":"Test it at the dairy","process":"inspect","text":"Tankers deliver milk to a dairy, where each load is sampled for fat, protein, temperature and antibiotics before it is allowed into the silos.","inputs":[]},{"name":"Spin out the cream","process":"separate","text":"Fresh milk will separate into cream and skim milk by itself after 12 to 24 hours. A centrifugal separator does it in moments, and the dairy puts back exactly as much cream as it needs for full cream, reduced fat or skim milk.","inputs":[]},{"name":"Break up the fat globules","process":"mold","text":"In homogenization the milk is pumped at high pressure through narrow gaps. Turbulence breaks the fat globules into smaller droplets, so cream stays mixed in and no layer forms on top.","inputs":[]},{"name":"Heat it briefly","process":"pasteurize","text":"In the standard high-temperature short-time process, a stack of steel plates heats the milk to 72 °C for 15 seconds. A plate on the other side lets cold incoming milk soak up the heat from the outgoing milk, which saves energy.","inputs":[],"spec":"72 °C for 15 seconds"},{"name":"Chill and bottle","process":"fill","text":"The milk is cooled right away and filled into cartons or jugs. Dairies print a best before date on every one.","inputs":[]}],"facts":["Louis Pasteur developed his gentler heating method during an 1864 summer holiday, to fix acidic wine.","Ultra-high-temperature treatment heats milk to 135 °C for just 1 to 2 seconds."],"where":[],"whereNote":null,"sources":[{"title":"Milk","url":"https://en.wikipedia.org/wiki/Milk"},{"title":"Pasteurization","url":"https://en.wikipedia.org/wiki/Pasteurization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"peanut-butter","name":"Peanut butter","kind":"product","category":"food","title":"How peanut butter is made","url":"https://assemblyline.org/make/peanut-butter","stations":6,"upstream":18,"downstream":0,"depth":4,"dek":"Peanut butter is just roasted peanuts ground fine, and a small dose of hardened oil stops it separating.","answer":"Shelled peanuts are roasted in large ovens, cooled, and blanched to rub off their skins. They are then ground in mills, first coarsely and then to a smooth paste, with salt and sugar added. Many brands add a stabilizer so the oil stays mixed. The paste is cooled and filled into jars.","aka":["peanut spread","nut butter","creamy peanut butter"],"inputs":["peanuts","table-salt","sugar","vegetable-oil"],"uses":[],"grounds":["peanuts","rock-salt","seawater","sugarcane","sugar-beet","water","soybeans","rapeseed","clay","limestone","crude-oil","natural-gas"],"upstreamSlugs":["peanuts","table-salt","sugar","vegetable-oil","rock-salt","seawater","sugarcane","sugar-beet","water","lime","soybeans","rapeseed","hexane","clay","limestone","crude-oil","hydrogen","natural-gas"],"downstreamSlugs":[],"steps":[{"name":"Shell and sort the nuts","process":"separate","text":"Harvested peanuts are dried, shelled and screened. Machines and workers pull out moldy or damaged kernels, which can carry toxins.","inputs":["peanuts"]},{"name":"Roast in the oven","process":"bake","text":"Dry roasting is done in a revolving batch oven or a continuous roaster. In one batch method the nuts are held at about 160 °C for roughly 40 to 60 minutes. Roasting makes the flavor and loosens the skins.","inputs":[],"spec":"about 160 °C for 40 to 60 minutes"},{"name":"Cool and blanch","process":"separate","text":"Roasted nuts are cooled quickly by air so they stop cooking. Rollers and air blowers rub off the skins, and the nuts are split to remove the bitter heart.","inputs":[]},{"name":"Grind the nuts","process":"grind","text":"Mills grind the nuts into a thick paste. The friction warms it, and the oil in the nuts liquefies and turns the crumbly grind into a flowing paste.","inputs":[]},{"name":"Season and stabilize","process":"mix","text":"Salt and sweetener go in. Smooth conventional brands may also get hydrogenated or palm-based oil that sets and traps the peanut oil, while natural peanut butter is just peanuts and a little salt and will separate.","inputs":["table-salt","sugar","vegetable-oil"]},{"name":"Cool and fill jars","process":"fill","text":"The warm paste is chilled and pumped into jars. Cooling the jar while it sits sets the stabilizer and keeps the oil in suspension.","inputs":[]}],"facts":["The Aztecs and Incas ground roasted peanuts into a paste.","John Harvey Kellogg was issued a peanut butter patent on May 24, 1898, and he boiled the peanuts rather than roasting them.","In 1922 the chemist Joseph Rosefield invented a way to keep the oil from separating, using partially hydrogenated oil."],"where":[],"whereNote":null,"sources":[{"title":"Peanut butter","url":"https://en.wikipedia.org/wiki/Peanut_butter"},{"title":"Hydrogenation","url":"https://en.wikipedia.org/wiki/Hydrogenation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"peanuts","name":"Peanuts","kind":"raw","category":"farm","title":"How peanuts are grown and harvested","url":"https://assemblyline.org/make/peanuts","stations":5,"upstream":0,"downstream":1,"depth":0,"dek":"A machine slices the taproot, flips the plant upside down and leaves the pods to dry in the open air for days.","answer":"Peanuts flower above ground, then push their pods into light, sandy soil on stalks called pegs. At harvest a digger-inverter cuts the taproot below the pods, shakes off the dirt and flips the plants into a fluffy windrow. Two or three days later a combine threshes the pods from the vines and blows them into a basket.","aka":["groundnuts","peanut farming","peanut harvest","goobers"],"inputs":[],"uses":["peanut-butter"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["peanut-butter"],"steps":[{"name":"Plant in sandy loam","process":"grow","text":"The crop wants light, sandy loam and warm weather all season, and harvest usually comes 90 to 150 days after planting, depending on type. Bacteria in root nodules fix nitrogen, so the plants gain little from nitrogen fertilizer and leave the soil better for the next crop.","inputs":[]},{"name":"Peg into the soil","process":"grow","text":"After fertilization a thread-like stalk called a peg lengthens and grows into the ground. The pod develops underground, a habit called geocarpy. Pods measure 3 to 7 centimeters.","inputs":[]},{"name":"Judge the digging date","process":"inspect","text":"Flowers keep opening while pods fill, so a field never ripens all at once. Dig too early and many pods are unripe. Dig too late and they snap off and stay in the soil. Growers lean on the hull-scrape method to judge maturity.","inputs":[]},{"name":"Cut, shake and invert","process":"harvest","text":"A horizontal blade clips the taproot just below the pods, and its slight pitch lifts the plant onto a conveyor of vibrating bars that knocks the soil loose. Wheels and rods then flip the plants into a well-aerated windrow with very few pods on the ground.","inputs":[],"spec":"3.5 to 5 mph digging speed"},{"name":"Thresh from the windrow","process":"separate","text":"Combining starts when the windrow has dried to 18 to 24 percent moisture. Cylinders pull pods off the vines, sieves and an air blast take out the trash, and stemmer saws cut off the stems. An air stream lifts the pods into an overhead basket, which empties into a drying wagon.","inputs":[],"spec":"18 to 24 percent moisture"}],"facts":["Peanut plants are 30 to 50 centimeters tall and their leaves close at night.","Peanuts are not true nuts but legumes, in the same family as peas.","American growers sort the crop into four market classes: Spanish, Runner, Virginia and Valencia."],"where":[{"place":"China","share":"36% of world output"},{"place":"India","share":"19%"}],"whereNote":"2023, share of the 54 million tonnes of groundnuts, excluding shelled, produced worldwide.","sources":[{"title":"Peanut","url":"https://en.wikipedia.org/wiki/Peanut"},{"title":"Peanut Digger and Combine Efficiency, University of Georgia Extension","url":"https://fieldreport.caes.uga.edu/publications/B1087/peanut-digger-and-combine-efficiency/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pearl-oyster","name":"Pearl oysters","kind":"raw","category":"farm","title":"How pearl oysters are farmed for pearls","url":"https://assemblyline.org/make/pearl-oyster","stations":5,"upstream":0,"downstream":1,"depth":0,"dek":"A cultured pearl begins as a surgical graft, a shell bead and a scrap of tissue from a donor oyster.","answer":"Pearl oysters are saltwater bivalves with a thick lining of nacre, and farmers run them as living pearl makers. A technician implants a polished shell bead and a scrap of mantle tissue from a donor oyster. The tissue forms a sac that coats the bead in nacre, and some oysters survive to take a larger bead.","aka":["pearl oyster","Akoya oyster","pearl farming"],"inputs":[],"uses":["cultured-pearl"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["cultured-pearl"],"steps":[{"name":"Raise the young shellfish","process":"grow","inputs":[],"spec":"about 2 years old at first seeding","text":"These oysters belong to the genus Pinctada and are not closely related to the edible kind. The big South Sea species is raised until it is about 2 years old before its first seeding."},{"name":"Graft bead and tissue","process":"assemble","inputs":[],"text":"A technician places a polished bead, cut from freshwater mussel shell, inside the host along with a small piece of mantle tissue from a donor. The tissue makes a pearl sac around the bead."},{"name":"Let the nacre build","process":"grow","text":"The sac secretes layer after layer of nacre, made of calcium carbonate and a fibrous protein. Oysters hang in the sea, and each layer thickens the pearl.","inputs":[],"spec":"twelve to eighteen months for a beaded pearl"},{"name":"Open the shells and sort","process":"harvest","inputs":[],"text":"Pearls are taken out and graded. Sea oysters usually carry one bead at a time, so volume stays low, while freshwater mussels take many grafts."},{"name":"Reseed the survivors","process":"assemble","inputs":[],"text":"South Sea and Tahitian oysters that survive the harvest are often given a new, larger bead in the same operation. They can be reseeded up to 3 or 4 times."}],"facts":["Before pearl farming, divers might find only three or four perfect pearls in a haul of three tons of oysters.","X-rays tell cultured from natural pearls, because a bead shows a solid center without growth rings.","A keshi pearl is made entirely of nacre when the tissue slips off the bead."],"where":[],"whereNote":null,"sources":[{"title":"Pearl","url":"https://en.wikipedia.org/wiki/Pearl"},{"title":"Cultured pearl","url":"https://en.wikipedia.org/wiki/Cultured_pearl"},{"title":"Pinctada","url":"https://en.wikipedia.org/wiki/Pearl_oyster"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"peas","name":"Peas","kind":"raw","category":"farm","title":"How peas are grown","url":"https://assemblyline.org/make/peas","stations":4,"upstream":0,"downstream":1,"depth":0,"dek":"Picked pods go off fast. Peas bound for the freezer race to the plant within a few hours of harvest.","answer":"This cool-season crop goes into the ground as soon as the soil warms to 10 °C and reaches maturity about 60 days later in many varieties. Viner machines strip the peas straight from the vines in the field. They spoil quickly once picked, so the crop is frozen, canned or dried within hours.","aka":["green peas","garden peas","Pisum sativum"],"inputs":[],"uses":["frozen-peas"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["frozen-peas"],"steps":[{"name":"Sow into cool soil","process":"grow","text":"Seed goes in once the soil reaches 10 °C. Depending on location, planting can run from winter to early summer. The crop grows best at 13 to 18 °C and does poorly in summer heat.","inputs":[]},{"name":"Let them climb together","process":"grow","text":"Plants pollinate themselves and fix nitrogen through bacteria in root nodules. In dense plantings the vines hold each other up. Each pod holds 5 to 10 seeds attached by short stalks.","inputs":[]},{"name":"Strip the vines","process":"harvest","text":"Specialized viner machines pull the immature peas from the vines at field scale. Snow peas and snap peas, whose tender pods are eaten whole, are still usually picked by hand.","inputs":[]},{"name":"Rush them to processing","process":"chill","text":"Pods do not keep once picked. Unless the peas are going to market fresh, they have to be frozen, canned or dried within a few hours. Field peas are the exception, left to mature and dry on the plant.","inputs":[]}],"facts":["Gregor Mendel used peas in a monastery garden for his pioneering work on heredity.","Eating fresh immature green peas was once an innovation of early modern European cuisine.","Peas were among the first vegetables to be canned."],"where":[{"place":"China and India combined","share":"86% of world output"}],"whereNote":"2023 world production of green peas, 21.5 million tonnes, as quoted on Wikipedia.","sources":[{"title":"Pea","url":"https://en.wikipedia.org/wiki/Pea"},{"title":"Pea (Britannica)","url":"https://www.britannica.com/plant/pea"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pencil","name":"Pencil","kind":"product","category":"wood-paper","title":"How pencils are made","url":"https://assemblyline.org/make/pencil","stations":8,"upstream":79,"downstream":0,"depth":10,"dek":"There is no lead in a pencil. There never was. The core is baked graphite and clay.","answer":"A pencil core starts as ground graphite and clay mixed with water, squeezed into thin strings, then fired in a kiln and soaked in wax. Machines lay those strings into grooves cut in a plank of cedar, glue a second plank on top, and slice the sandwich into separate pencils. Paint, a metal ferrule and an eraser finish it.","aka":["lead pencil","graphite pencil","wooden pencil"],"inputs":["natural-graphite","clay","water","paraffin-wax","lumber","adhesive","paint","aluminum","rubber"],"uses":[],"grounds":["natural-graphite","clay","water","crude-oil","timber","coal","natural-latex","sulfur","natural-gas","titanium-ore","iron-ore","bauxite","air","rock-salt","limestone","tin-ore","corn","sugarcane","soybeans","rapeseed","dolomite","manganese-ore","quartz","sugar-beet"],"upstreamSlugs":["natural-graphite","clay","water","paraffin-wax","lumber","adhesive","paint","aluminum","rubber","crude-oil","hydrogen","timber","polyethylene","acrylic","epoxy","polyurethane","titanium-dioxide","pigment","tin-can","coal","petroleum-coke","alumina","natural-latex","synthetic-rubber","carbon-black","sulfur","natural-gas","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","titanium-ore","coke","oxygen","iron-ore","tinplate","lacquer","ink","bauxite","lime","naphtha","benzene","styrene","air","rock-salt","steel","tin","ethanol","vegetable-oil","phenolic-resin","limestone","toluene","pig-iron","magnesium","steel-scrap","manganese","argon","tin-ore","corn","sugarcane","yeast","soybeans","rapeseed","hexane","formaldehyde","dolomite","silicon","propane","manganese-ore","molasses","quartz","charcoal","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Wet-mix the core paste","process":"mix","text":"Finely ground graphite and clay powder are cleaned, dried and combined with water. The recipe sets the grade. More clay gives a harder, paler line, and less clay gives a softer, blacker one.","inputs":["natural-graphite","clay","water"],"spec":"grades from 9H to 9B"},{"name":"Squeeze out thin strings","process":"extrude","text":"The paste is forced through a narrow die and comes out looking like spaghetti. The strings are straightened, dried and cut to length while they are still fragile.","inputs":[]},{"name":"Fire the strings","process":"fire","text":"A kiln tempers the dried strings so the clay fuses around the graphite. They go in crumbly and come out hard enough to survive a sharpener.","inputs":[]},{"name":"Soak them in wax","process":"coat","text":"Firing leaves tiny pores. Dipping the strings in oil or molten wax fills those pores, and that filling is why a good pencil glides over paper instead of scratching.","inputs":["paraffin-wax"]},{"name":"Groove the cedar slats","process":"machine","text":"Planks of incense-cedar or juniper get a row of long parallel grooves. Each groove is half of the channel that will hold one core.","inputs":["lumber"]},{"name":"Sandwich and glue","process":"laminate","text":"Strings drop into the grooves of one slat. A second grooved slat is glued on top, closing every channel around its core.","inputs":["adhesive"]},{"name":"Slice into separate sticks","process":"cut","text":"Cutters run through the glued sandwich along the lines between the cores. One block falls apart into a row of individual pencils.","inputs":[]},{"name":"Paint and add the eraser","process":"assemble","text":"The pencils are painted or varnished, and a shoulder is cut at one end. A metal ferrule grips that shoulder and holds a rubber plug.","inputs":["paint","aluminum","rubber"]}],"facts":["Pencil cores have always been graphite, but early users mistook it for a form of lead and the name stuck.","More than 14 billion pencils are made worldwide each year.","Two pencils with the same grade stamp can differ widely, with graphite content running from about 30 to 65 percent."],"where":[],"whereNote":null,"sources":[{"title":"Pencil","url":"https://en.wikipedia.org/wiki/Pencil"},{"title":"Graphite","url":"https://en.wikipedia.org/wiki/Graphite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"penicillin","name":"Penicillin","kind":"product","category":"body-health","title":"How penicillin is made","url":"https://assemblyline.org/make/penicillin","stations":7,"upstream":23,"downstream":0,"depth":6,"dek":"The best penicillin-making mold was found on a moldy cantaloupe in a market in Peoria, Illinois.","answer":"Penicillin is grown, not assembled. A mold, Penicillium chrysogenum, is fed sugars and corn steep liquor in large stirred, aerated tanks. After days of fermentation the drug is filtered from the broth and purified. For many drugs in the penicillin family, the natural molecule is then chemically modified, and the final powder is made sterile.","aka":["antibiotic","penicillin G","penicillin V"],"inputs":["corn","sugar","water","air","glass-bottle"],"uses":[],"grounds":["corn","water","air","sugarcane","sugar-beet","silica-sand","limestone","rock-salt","trona","natural-gas","crude-oil"],"upstreamSlugs":["corn","sugar","water","air","glass-bottle","sugarcane","sugar-beet","lime","silica-sand","soda-ash","limestone","polyethylene","rock-salt","ammonia","carbon-dioxide","trona","ethylene","natural-gas","yeast","naphtha","molasses","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Prepare the seed culture","process":"grow","text":"A small sample of mold is grown in flasks and then in progressively larger vessels. This builds up enough healthy mold to start a full-size tank.","inputs":[]},{"name":"Mix the nutrient broth","process":"mix","text":"Corn steep liquor, a by-product of corn wet milling, is mixed with sugar and water and sterilized with steam. It is rich in the nutrients the mold needs.","inputs":["corn","sugar","water"]},{"name":"Ferment in deep tanks","process":"ferment","text":"Mold goes into enormous stainless steel tanks and stirred while sterile air is pumped in. The mold needs oxygen, so airflow and agitation are monitored continuously.","inputs":["air"]},{"name":"Filter out the mold","process":"separate","text":"When the broth holds as much drug as it will, filters remove the mold. What remains is a liquid containing dilute penicillin.","inputs":[]},{"name":"Extract and purify","process":"refine","text":"The drug is moved from the broth into a solvent and back into water, then crystallized. These steps strip away the other products of fermentation.","inputs":[]},{"name":"Modify the molecule","process":"react","text":"Many penicillins used today are semisynthetic. The natural core is chemically altered in a plant to make versions that work against more bacteria or survive stomach acid.","inputs":[]},{"name":"Sterilize and pack","process":"pasteurize","text":"The purified drug is filtered through sterile membranes and dried. It is then filled into vials or made into tablets and capsules.","inputs":["glass-bottle"]}],"facts":["Alexander Fleming discovered penicillin in 1928 as a crude extract of a mold.","The moldy cantaloupe from Peoria held a strain that made six times as much penicillin as Fleming's mold.","Research on corn steep liquor let the United States make 2.3 million doses in time for the invasion of Normandy in spring 1944."],"where":[],"whereNote":null,"sources":[{"title":"Penicillin","url":"https://en.wikipedia.org/wiki/Penicillin"},{"title":"Fermentation in food processing","url":"https://en.wikipedia.org/wiki/Fermentation_in_food_processing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pentane","name":"Pentane","kind":"material","category":"chemicals","title":"How pentane is made","url":"https://assemblyline.org/make/pentane","stations":5,"upstream":2,"downstream":2,"depth":1,"dek":"It boils near 36 °C, close to body temperature, and that is exactly why foam makers trap it in plastic beads.","answer":"This five-carbon hydrocarbon is already in crude oil and natural gas, so nothing has to be built. Gas plants and refineries separate it from heavier and lighter molecules by fractional distillation, then rectify it further. Most of its fame comes from foam, where it boils inside polystyrene beads and swells them up.","aka":["n-pentane","isopentane","pentanes","C5"],"inputs":["natural-gas","crude-oil"],"uses":["polystyrene-foam","foam-cup"],"grounds":["natural-gas","crude-oil"],"upstreamSlugs":["natural-gas","crude-oil"],"downstreamSlugs":["polystyrene-foam","foam-cup"],"steps":[{"name":"Strip liquids from gas","process":"separate","text":"Raw natural gas is cooled so that heavier hydrocarbons condense. Pressure drops across a control valve flash the lightest ones away from a liquid called condensate, which holds propane, butane, pentane and hexane.","inputs":["natural-gas"]},{"name":"Distill from crude","process":"refine","text":"Refineries get the same molecules from fractional distillation of petroleum. A light cut comes off with a boiling range that takes in the five-carbon compounds.","inputs":["crude-oil"]},{"name":"Rectify the cut","process":"refine","text":"Repeated distillations narrow the stream down until five-carbon hydrocarbons dominate. The three isomers boil from about 9 to 36 °C, and the most branched boils lowest.","inputs":[]},{"name":"Rearrange some isomers","process":"react","text":"An acid catalyst turns part of the normal form into isopentane, valued in high-octane fuel. The straight-chain form alone rates just 62.","inputs":[]},{"name":"Send out for foam","process":"fill","text":"Sealed tankers take it to chemical plants. There it soaks into polystyrene beads as a blowing agent, a job it took over from CFCs in the 1970s. Other shipments go to refrigerant blenders and geothermal power stations.","inputs":[]}],"facts":["Polystyrene foams are 95 to 98 percent air.","Carl Schorlemmer discovered normal pentane in 1862 while analyzing products from the cannel coal mined in Wigan.","Pentane occurs in hop oil and in alcoholic drinks."],"where":[],"whereNote":null,"sources":[{"title":"Pentane","url":"https://en.wikipedia.org/wiki/Pentane"},{"title":"Natural-gas condensate","url":"https://en.wikipedia.org/wiki/Natural-gas_condensate"},{"title":"Polystyrene","url":"https://en.wikipedia.org/wiki/Polystyrene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"perfume","name":"Perfume","kind":"product","category":"body-health","title":"How perfume is made","url":"https://assemblyline.org/make/perfume","stations":7,"upstream":25,"downstream":6,"depth":6,"dek":"Even pure perfume is only 15 to 30% scent oil, and the rest is mostly alcohol.","answer":"Perfume starts with fragrant oils pulled from plants, by steam distillation, solvent extraction or pressing, or built in a chemical plant. A perfumer blends dozens of these into a concentrate, which is diluted in alcohol, left to rest for weeks, chilled, filtered and filled into glass bottles.","aka":["parfum","fragrance","eau de parfum","cologne"],"inputs":["oranges","vanilla-pods","water","ethanol","glass-bottle"],"uses":["shampoo","deodorant","air-freshener","dish-soap","hairspray","foundation-makeup"],"grounds":["oranges","vanilla-pods","water","corn","sugarcane","silica-sand","limestone","natural-gas","rock-salt","trona","sugar-beet","crude-oil","air"],"upstreamSlugs":["oranges","vanilla-pods","water","ethanol","glass-bottle","corn","sugarcane","yeast","ethylene","silica-sand","soda-ash","limestone","polyethylene","molasses","naphtha","natural-gas","rock-salt","ammonia","carbon-dioxide","lime","trona","sugar-beet","crude-oil","hydrogen","air"],"downstreamSlugs":["shampoo","deodorant","air-freshener","dish-soap","hairspray","foundation-makeup"],"steps":[{"name":"Collect the plant oils","process":"harvest","text":"Flowers, citrus peel, vanilla pods, resins and woods are gathered. Each material is harvested at the point its aroma is strongest.","inputs":["oranges","vanilla-pods"]},{"name":"Distill the scent","process":"refine","text":"Steam from boiling water passes through the raw material and carries the volatile aroma compounds with it. The steam condenses, and the oil separates and floats to the top of the water.","inputs":["water"]},{"name":"Extract the delicate ones","process":"separate","text":"Fragile flowers such as jasmine would be ruined by steam, so a solvent or fat draws out their scent instead. The waxy residue is then washed with ethanol to leave the pure oil.","inputs":["ethanol"]},{"name":"Build the blend","process":"mix","text":"A perfumer combines natural oils with lab-made aroma molecules into a concentrate called the compound. Some formulas contain dozens of ingredients.","inputs":[]},{"name":"Dilute in alcohol","process":"mix","text":"The concentrate is mixed into ethanol, or ethanol and water. A strong pure perfume holds 15 to 30% aromatic compounds, and lighter eau de toilette sprays hold far less.","inputs":["ethanol"]},{"name":"Rest and filter","process":"separate","text":"The mixture is left to settle so the ingredients stabilize, then it is chilled and filtered to remove any sediment and cloud.","inputs":[]},{"name":"Bottle it","process":"fill","text":"Filtered perfume is filled into glass bottles under a spray pump, and the cap is fitted.","inputs":["glass-bottle"]}],"facts":["The strongest form, parfum, holds 15 to 30% aromatic compounds.","Perfume can also be diluted in neutral-smelling oils, such as jojoba, instead of alcohol."],"where":[],"whereNote":null,"sources":[{"title":"Perfume","url":"https://en.wikipedia.org/wiki/Perfume"},{"title":"Deodorant","url":"https://en.wikipedia.org/wiki/Deodorant"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pet-plastic","name":"PET plastic","kind":"material","category":"plastics","title":"How PET plastic is made","url":"https://assemblyline.org/make/pet-plastic","stations":6,"upstream":17,"downstream":108,"depth":5,"dek":"The plastic in a soda bottle is the same polyester as a fleece jacket, made by joining two petrochemicals.","answer":"PET is made by reacting terephthalic acid with ethylene glycol, which releases water and links the molecules into chains. The molten polymer is cooled, chopped into chips and then heated in a dryer until the chains grow longer and the chips turn from clear to semi-crystalline. Bottle makers remelt the chips.","aka":["PETE","polyethylene terephthalate","polyester resin"],"inputs":["p-xylene","ethylene","ethylene-glycol"],"uses":["polyester","plastic-bottle","credit-card","3d-printer-filament","drum-kit","bottled-water"],"grounds":["natural-gas","water","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","water","oxygen","carbon-dioxide","crude-oil","hydrogen","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["polyester","plastic-bottle","credit-card","3d-printer-filament","drum-kit","bottled-water","tire","soccer-ball","marker-pen","highlighter","sofa","office-chair","pillow","garden-hose","volleyball","kite","kitchen-sponge","wet-wipes","seat-belt","canoe","sailboat","hoodie","leggings","swimsuit","raincoat","backpack","suitcase","shoelace","curtain","flag","wireless-earbuds","microphone","sneaker","mattress","umbrella","zipper","button","thread","teddy-bear","shampoo","sunscreen","aspirin","detergent","bleach","vitamin-c","ketchup","cola","sparkling-water","soda","dish-soap","hair-dye","foundation-makeup","mouthwash","cough-syrup","car","electric-car","bicycle","motorcycle","down-jacket","handbag","jeans","dress-shirt","suit","baseball-cap","airbag","baseball","fireworks","bike-helmet","candle","ice-skates","fishing-rod","football","yo-yo","fashion-doll","tampon","silk-tie","underwear","winter-gloves","leather-belt","wallet","hiking-boots","high-heels","felt-hat","blanket","book","t-shirt","socks","sweater","leather-shoe","towel","flour","bread","instant-noodles","tortilla","croissant","donut","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","fish-sticks","modeling-clay","licorice","cake-mix"],"steps":[{"name":"Make the acid and the glycol","process":"react","text":"Terephthalic acid is made by oxidizing p-xylene, an aromatic compound that comes from refining naphtha. Ethylene glycol is made from ethylene.","inputs":["p-xylene","ethylene"]},{"name":"Combine them into short chains","process":"react","text":"The acid and glycol are heated together in a condensation reaction. Water leaves as vapor, and the product is a short-chained compound called BHET.","inputs":["ethylene-glycol"]},{"name":"Grow the chains under vacuum","process":"react","text":"Under vacuum and heat, the short chains link up into long ones, and excess glycol is drawn off. The liquid thickens like warm honey.","inputs":[]},{"name":"Extrude and chip the strands","process":"cut","text":"Molten polymer is pushed through a die into strands, cooled in water, and cut into small chips. At this point the plastic is amorphous and transparent.","inputs":[]},{"name":"Bake the chips in a dryer","process":"dry","text":"Chips are heated in the solid state, which crystallizes them and lengthens the chains further. The chips go from clear to cloudy white, and the plastic becomes stronger.","inputs":[]},{"name":"Bag the resin","process":"package","text":"Chips are loaded into silos and shipped to bottle makers and fiber spinners. Because moisture degrades molten PET, the chips are dried once more before they are melted again.","inputs":[]}],"facts":["More than 60% of PET goes into polyester fibers rather than packaging.","PET can be either transparent and amorphous or semi-crystalline and opaque, depending on how it is processed and cooled."],"where":[],"whereNote":null,"sources":[{"title":"Polyethylene terephthalate","url":"https://en.wikipedia.org/wiki/Polyethylene_terephthalate"},{"title":"Terephthalic acid","url":"https://en.wikipedia.org/wiki/Terephthalic_acid"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"petroleum-coke","name":"Petroleum coke","kind":"material","category":"chemicals","title":"How petroleum coke is made","url":"https://assemblyline.org/make/petroleum-coke","stations":6,"upstream":1,"downstream":159,"depth":1,"dek":"Refineries bake the last dregs of crude into rock, then cut it out of steel drums with high-pressure water.","answer":"After a refinery has taken what it can from crude, a heavy residue is left. A delayed coker heats that to about 480 to 505 °C and sends it into a tall drum, where it cracks into lighter oils and a solid carbon rock. Water jets cut the solid out. Clean grades become anodes for aluminum smelters, and the rest is fuel.","aka":["petcoke","pet coke","green coke","needle coke","calcined petroleum coke"],"inputs":["crude-oil"],"uses":["synthetic-graphite","aluminum"],"grounds":["crude-oil"],"upstreamSlugs":["crude-oil"],"downstreamSlugs":["synthetic-graphite","aluminum","lithium-ion-cell","synthetic-diamond","deodorant","lipstick","microchip","led-bulb","oled-screen","ev-battery","smartphone","laptop","hard-drive","solid-state-drive","solar-cell","solar-panel","refrigerator","washing-machine","satellite","pencil","aluminum-foil","brass","cobalt","chromium","nonstick-pan","aluminum-can","mirror","skyscraper","car","electric-car","car-engine","airplane","rocket","bicycle","motorcycle","skateboard","drum-kit","pencil-eraser","pressure-cooker","toaster","air-conditioner","ceiling-fan","office-chair","ski","yo-yo","toy-car","eyeshadow","asthma-inhaler","prosthetic-leg","wheelchair","ladder","double-glazed-window","aluminum-window-frame","subway-train","sailboat","suitcase","smartwatch","microphone","camera-lens","vinyl-record","compact-disc","game-console","graphics-card","vanadium","newspaper","zipper","n95-mask","drone","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","hearing-aid","pacemaker","thermometer","credit-card","television","computer-keyboard","computer-mouse","airbag","phone-charger","usb-cable","wifi-router","inkjet-printer","remote-control","toothpaste","aspirin","condom","aa-battery","wristwatch","faucet","padlock","tire","electric-guitar","trumpet","ballpoint-pen","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","light-switch","power-outlet","leather-belt","handbag","flag","hip-implant","turbine-blade","tungsten-carbide","stent","stainless-steel","safety-pin","razor-blade","ice-skates","dumbbell","wrench","nichrome","leather","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","locomotive","down-jacket","raincoat","backpack","jeans","jet-engine","saw-blade","syringe","electric-kettle","kitchen-knife","fork","elevator","thermos","water-bottle","blender","dishwasher","golf-club","baseball","basketball","tennis-racket","football","winter-gloves","wallet","hiking-boots","high-heels","leather-shoe"],"steps":[{"name":"Collect the heavy residue","process":"refine","text":"Residual oil left at the bottom of vacuum distillation is pumped to the coker's main fractionator. Hot vapors preheat it there before it goes on to the furnace.","inputs":["crude-oil"]},{"name":"Fire through the furnace","process":"cook","text":"The oil and some injected steam run through furnace tubes and reach about 480 to 505 °C, its cracking temperature. The steam keeps the flow fast, so the solid does not form in the tubes. That delay gives the process its name.","inputs":[]},{"name":"Crack it in a drum","process":"react","text":"Cracking finishes in a huge drum, up to 10 meters across and 43 meters tall. Lighter oils leave as vapor, and solid carbon builds up inside over 12 to 24 hours while a second drum waits its turn.","inputs":[]},{"name":"Steam and quench","process":"chill","text":"Steam sweeps out remaining hydrocarbons from the filled drum. Water then floods it for several hours to cool the mass, and is drained away.","inputs":[]},{"name":"Cut it out with water","process":"cut","text":"With the heads of the drum removed, a high-pressure water jet on a rotating drill stem bores through the mass and cuts it free. Green lumps fall into a pit below.","inputs":[]},{"name":"Calcine the best grades","process":"fire","text":"Low-sulfur, low-metal coke tumbles through a rotary kiln that drives off remaining volatile hydrocarbons. It goes on to make aluminum anodes and synthetic graphite. High-metal coke skips this and is burned as fuel.","inputs":[]}],"facts":["Delayed coking turns about 18 to 30 percent of the residue into solid coke by weight.","Some refineries produce as much as 2,000 to 3,000 tons of petroleum coke a day.","Burned for energy, petcoke emits 5% to 10% more carbon dioxide than coal."],"where":[],"whereNote":null,"sources":[{"title":"Petroleum coke","url":"https://en.wikipedia.org/wiki/Petroleum_coke"},{"title":"Delayed coker","url":"https://en.wikipedia.org/wiki/Delayed_coker"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"phenol","name":"Phenol","kind":"material","category":"chemicals","title":"How phenol is made","url":"https://assemblyline.org/make/phenol","stations":5,"upstream":10,"downstream":244,"depth":5,"dek":"Phenol was once pulled from coal tar. Now a chain reaction in air makes it, with acetone as a free passenger.","answer":"Most phenol comes from the cumene process. Benzene and propylene are joined into cumene, the cumene is oxidized with air, and an acid then splits the product into phenol and acetone. Plants turn out about 10.8 million tonnes of phenol this way each year, and most of it becomes plastics and resins.","aka":["carbolic acid","hydroxybenzene"],"inputs":["benzene","propylene","air"],"uses":["aspirin","acetaminophen","polycarbonate","epoxy","billiard-ball","brake-pad","phenolic-resin"],"grounds":["air","crude-oil","water","natural-gas","coal"],"upstreamSlugs":["benzene","propylene","air","naphtha","hydrogen","toluene","crude-oil","water","natural-gas","coal"],"downstreamSlugs":["aspirin","acetaminophen","polycarbonate","epoxy","billiard-ball","brake-pad","phenolic-resin","led-bulb","drone","eyeglass-lens","sunglasses","bike-helmet","blender","suitcase","smartwatch","wireless-earbuds","phone-charger","digital-camera","camera-lens","compact-disc","game-console","thermometer","adhesive","printed-circuit-board","wind-turbine","electric-motor","rebar","aluminum-can","airplane","surfboard","ski","snowboard","tennis-racket","fishing-rod","prosthetic-leg","loudspeaker","umbrella","ink","photoresist","eyeglass-frame","adhesive-bandage","credit-card","duct-tape","ev-battery","pencil","nail","insulation","popcorn","windshield","skateboard","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","pencil-eraser","clear-tape","staple","sofa","ice-skates","golf-club","volleyball","cricket-bat","dartboard","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","globe","snow-globe","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","sailboat","dress-shirt","suit","raincoat","handbag","wallet","flip-flops","hiking-boots","high-heels","microphone","e-reader","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","sneaker","leather-shoe","baseball-cap","carpet","mattress","diaper","hearing-aid","pacemaker","smartphone","laptop","television","hard-drive","solid-state-drive","computer-keyboard","computer-mouse","microwave-oven","washing-machine","satellite","car","electric-car","airbag","rocket","locomotive","motorcycle","elevator","ceiling-fan","treadmill","smoke-detector","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","refrigerator","vacuum-cleaner","dishwasher","air-conditioner","subway-train","concrete","skyscraper","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","syringe","plastic-bag","tin-can","golf-ball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","wallpaper","marker-pen","highlighter","frisbee","trading-cards","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flag","vinyl-record","newspaper","banknote","t-shirt","microchip","memory-chip","lcd-screen","indium-tin-oxide","aluminum-window-frame","shipping-container","toothbrush","fireworks","plastic-wrap","cake-mix","hair-dye","tampon","soap","toothpaste","detergent","nitrile-glove","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","cough-syrup","wheelbarrow","light-switch","facial-tissue","paint","condensed-milk","baby-formula","coconut-milk","canned-soup","usb-cable","oled-screen","aa-battery","candy-cane","scissors","mirror","container-ship","bicycle","water-bottle","water-heater","bowling-ball","dice","action-figure","fashion-doll","toy-car","coil-spring","hammer","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","leather-belt","toffee","padlock"],"steps":[{"name":"Join benzene and propylene","process":"react","text":"The two cheap feedstocks are compressed together with an acid catalyst. They combine into cumene, which is isopropyl benzene.","inputs":["benzene","propylene"]},{"name":"Oxidize the cumene with air","process":"react","text":"Air is bubbled through the cumene with a small amount of a radical starter. A chain reaction builds up cumene hydroperoxide, an unstable intermediate that plants keep under pressure and carefully controlled.","inputs":["air"]},{"name":"Split it with acid","process":"react","text":"An acid breaks the hydroperoxide into two products in a single step. The result is phenol plus acetone, two chemicals with a ready market.","inputs":[]},{"name":"Distill the two apart","process":"refine","text":"Columns separate acetone, phenol and left-over cumene. Unused cumene returns to the start of the line.","inputs":[]},{"name":"Ship the liquid","process":"fill","text":"Phenol is stored as a liquid and moved to plants that make resins and plastics.","inputs":[]}],"facts":["Nearly 10.8 million tonnes of phenol were made by the cumene process in 2022.","The process was invented in the Soviet Union in 1942 and independently by Heinrich Hock in 1944.","Joseph Lister used phenol, then called carbolic acid, in his pioneering antiseptic surgery."],"where":[],"whereNote":null,"sources":[{"title":"Phenol","url":"https://en.wikipedia.org/wiki/Phenol"},{"title":"Cumene process","url":"https://en.wikipedia.org/wiki/Cumene_process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"phenolic-resin","name":"Phenolic resin","kind":"material","category":"plastics","title":"How phenolic resin is made","url":"https://assemblyline.org/make/phenolic-resin","stations":5,"upstream":13,"downstream":171,"depth":6,"dek":"This was the first commercial synthetic resin. Its biggest job today is gluing plywood together.","answer":"Phenol and formaldehyde, heated together with a catalyst, build a soft prepolymer. Excess phenol with an acid gives a solid novolac, and excess formaldehyde with a base gives a liquid resole. Heat and pressure then cross-link either one into a hard, heat-resistant solid that will never melt again, found in plywood, billiard balls and brake linings.","aka":["phenol formaldehyde resin","Bakelite","novolac","resole","phenoplast"],"inputs":["phenol","formaldehyde"],"uses":["ink","photoresist","brake-pad"],"grounds":["air","water","crude-oil","natural-gas","coal"],"upstreamSlugs":["phenol","formaldehyde","benzene","propylene","air","methanol","water","naphtha","hydrogen","toluene","crude-oil","natural-gas","coal"],"downstreamSlugs":["ink","photoresist","brake-pad","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","microchip","memory-chip","printed-circuit-board","lcd-screen","indium-tin-oxide","vacuum-cleaner","electric-kettle","cotton-candy","pillow","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","car","electric-car","soap","toothpaste","detergent","nitrile-glove","washing-machine","paperclip","donut","corn-flakes","popcorn","crayon","fireworks","candle","salsa","fish-sticks","zip-bag","blender","dishwasher","cotton-swab","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","hearing-aid","pacemaker","thermometer","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","airbag","rocket","smartwatch","phone-charger","usb-cable","digital-camera","e-reader","graphics-card","electric-toothbrush","led-bulb","ev-battery","hard-drive","wind-turbine","microwave-oven","airplane","locomotive","motorcycle","elevator","ceiling-fan","treadmill","pinball-machine","oled-screen","refrigerator","pencil","scissors","mirror","container-ship","shipping-container","bicycle","wooden-chair","water-bottle","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","subway-train","leather-belt","eyeglass-frame","toffee","skyscraper","padlock"],"steps":[{"name":"Charge the reactor","process":"mix","text":"Phenol and formaldehyde go into a vessel with a catalyst. The ratio decides the product. Excess phenol with an acid heads for novolac, and excess formaldehyde with a base in water heads for resole.","inputs":["phenol","formaldehyde"]},{"name":"Cook the prepolymer","process":"react","text":"Heating attaches formaldehyde to the phenol rings, then links the rings into short chains of about 10 to 20 units. The reaction stops well before the batch sets solid.","inputs":[]},{"name":"Grind the solid grade","process":"grind","text":"Cooled novolac is a solid that can still soften with heat. It is ground to powder. Resole usually stays liquid or in solution, ready to spread between wood veneers.","inputs":[]},{"name":"Add filler and hardener","process":"mix","text":"Molding powders get fillers such as wood flour, minerals or glass fibers, plus a hardener such as hexamethylenetetramine, which supplies formaldehyde when hot. The filler adds strength to a resin that would otherwise be brittle.","inputs":[]},{"name":"Cure under heat and pressure","process":"press","text":"A pressurized hot mold or a veneer press finishes the job. Cross-links form throughout, creating a network that cannot melt or dissolve. Baekeland's insight was that pressure stops the batch foaming into a brittle mess.","inputs":[]}],"facts":["Leo Baekeland began this research after selling the rights to his Velox photographic paper to Eastman Kodak for $750,000.","Baekeland's first goal was a replacement for shellac, a material made from the secretion of lac insects.","Baekeland filed for his Bakelite process in 1907, and it was the first synthetic thermosetting plastic."],"where":[],"whereNote":null,"sources":[{"title":"Phenol formaldehyde resin","url":"https://en.wikipedia.org/wiki/Phenol_formaldehyde_resin"},{"title":"Bakelite","url":"https://en.wikipedia.org/wiki/Bakelite"},{"title":"Phenol-formaldehyde resin (Britannica)","url":"https://www.britannica.com/science/phenol-formaldehyde-resin"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"phone-charger","name":"Phone charger","kind":"product","category":"electronics","title":"How phone chargers are made","url":"https://assemblyline.org/make/phone-charger","stations":8,"upstream":89,"downstream":0,"depth":9,"dek":"About 30 workers can build 8,000 phone chargers in an eight-hour day, and each one takes more than 20 steps.","answer":"A phone charger contains a small circuit board that turns mains alternating current into low-voltage direct current. Parts are plugged into the board and soldered, and the flux is brushed off. The board is tested, fitted into a plastic case, run under load in an aging test, then sealed by ultrasonic welding and tested again before packing.","aka":["USB charger","wall adapter","power adapter"],"inputs":["copper-wire","transformer","ferrite","printed-circuit-board","microchip","solder","polycarbonate","abs-plastic","brass"],"uses":[],"grounds":["iron-ore","manganese-ore","air","copper-ore","water","silica-sand","limestone","quartz","tin-ore","crude-oil","coal","gold-ore","lead-ore","silver-ore","zinc-ore","rock-salt","natural-gas","sulfur","dolomite","trona","bauxite","titanium-ore","timber","corn","sugarcane","sugar-beet"],"upstreamSlugs":["copper-wire","transformer","ferrite","printed-circuit-board","microchip","solder","polycarbonate","abs-plastic","brass","copper","sheet-steel","steel","iron-ore","zinc-oxide","manganese-ore","fiberglass","epoxy","photoresist","silicon-wafer","oxygen","tin","aluminum","gold","lead","silver","phenol","propylene","acetone","caustic-soda","chlorine","naphtha","ammonia","air","benzene","ethylene","styrene","pigment","zinc","copper-ore","water","sulfuric-acid","pig-iron","magnesium","steel-scrap","lime","manganese","argon","silica-sand","limestone","soda-ash","phenolic-resin","polysilicon","quartz","tin-ore","coke","crude-oil","coal","petroleum-coke","alumina","gold-ore","lead-ore","silver-ore","zinc-ore","rock-salt","hydrogen","natural-gas","toluene","titanium-dioxide","carbon-black","sulfur","dolomite","silicon","propane","carbon-dioxide","trona","formaldehyde","hydrochloric-acid","trichlorosilane","nitrogen","bauxite","titanium-ore","charcoal","timber","corn","yeast","methanol","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Wind the transformer","process":"assemble","text":"Fine copper wire is wound around a small core in two separate coils. The transformer steps the wall voltage down and keeps the high-voltage side electrically separate from the phone cable.","inputs":["copper-wire","transformer","ferrite"]},{"name":"Place the components","process":"assemble","text":"Capacitors, resistors, diodes, the transformer and a controller chip are placed on the printed board, some by machine and some plugged in by hand.","inputs":["printed-circuit-board","microchip"]},{"name":"Solder and brush the board","process":"weld","text":"Solder joins every part to the board. Workers then brush away the flux residue and check the joints.","inputs":["solder"]},{"name":"Test the bare board","process":"inspect","text":"The assembled board is powered on and checked for output and load, so bad units are caught before they go into a case.","inputs":[]},{"name":"Mold the case","process":"mold","text":"Flame-retardant polycarbonate or ABS plastic is injected into steel molds to make the two halves of the casing. Flame resistance is a safety requirement for anything plugged into the wall.","inputs":["polycarbonate","abs-plastic"]},{"name":"Fit the prongs and port","process":"assemble","text":"Brass prongs are pressed into the back half and a USB port is mounted on the front. The board is soldered to them and set into the case.","inputs":["brass"]},{"name":"Run the aging test","process":"inspect","text":"Assembled chargers run under load for a period on an aging rack. Weak parts tend to fail here, before the case is sealed.","inputs":[]},{"name":"Weld the case shut","process":"weld","text":"An ultrasonic welder melts the plastic where the two halves meet, with no glue or screws. Each unit gets a last check before packing.","inputs":[]}],"facts":["A charger's transformer can be tiny because it switches at several hundred kilohertz or more, where a linear supply's transformer works at 50 or 60 Hz.","Lithium-ion batteries cannot handle indefinite trickle charging, so the charging has to stop on its own."],"where":[],"whereNote":null,"sources":[{"title":"Battery charger","url":"https://en.wikipedia.org/wiki/Battery_charger"},{"title":"Switched-mode power supply","url":"https://en.wikipedia.org/wiki/Switched-mode_power_supply"},{"title":"Charger production and testing process (IET Charger)","url":"https://www.ietcharger.com/charger-production-and-testing-process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"phosphate-rock","name":"Phosphate rock","kind":"raw","category":"ground","title":"How phosphate rock is mined","url":"https://assemblyline.org/make/phosphate-rock","stations":3,"upstream":0,"downstream":4,"depth":0,"dek":"Phosphate rock is sometimes made of fossil bone beds, and raw ore holds as little as 4% phosphorus pentoxide.","answer":"Phosphate rock is a sedimentary rock rich in apatite, laid down on ancient sea floors. Miners strip off the surface and dig the ore. A plant crushes and washes it into a slurry, floats the phosphate away from waste with froth, and may heat it. The enriched rock is mostly turned into fertilizer.","aka":["phosphorite","rock phosphate"],"inputs":[],"uses":["fertilizer","phosphoric-acid"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["fertilizer","phosphoric-acid","cola","soda"],"steps":[{"name":"Dig the phosphorite","process":"mine","text":"Phosphorite forms dark brown to black beds, from centimeters to several meters thick, often with limestone and mudstone. Most mines remove the soil above and dig the bed in open cuts.","inputs":[]},{"name":"Crush and wash to slurry","process":"wash","text":"The mined ore is crushed and washed with water, which makes a slurry and carries off the finest clay.","inputs":[]},{"name":"Float and calcine","process":"separate","text":"Froth flotation concentrates the phosphate into marketable rock phosphate, and some plants calcine it as well. Grade matters, since raw ore varies widely in how much phosphate it holds.","inputs":[]}],"facts":["Bone beds, made of small fragments of fossil skeletons, are one kind of phosphate deposit.","Commercially mined phosphorites occur in France, Belgium, Spain, Morocco, Tunisia, Saudi Arabia and Algeria."],"where":[{"place":"China","share":"77 megatonnes"},{"place":"United States","share":"29.4 megatonnes"},{"place":"Morocco","share":"26.8 megatonnes"}],"whereNote":"Phosphate rock mined in 2012, out of 195 megatonnes worldwide.","sources":[{"title":"Phosphate rock","url":"https://en.wikipedia.org/wiki/Phosphate_rock"},{"title":"Limestone","url":"https://en.wikipedia.org/wiki/Limestone"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"phosphoric-acid","name":"Phosphoric acid","kind":"material","category":"chemicals","title":"How phosphoric acid is made","url":"https://assemblyline.org/make/phosphoric-acid","stations":5,"upstream":8,"downstream":2,"depth":2,"dek":"Most phosphoric acid is made by dissolving rock in sulfuric acid, and the waste is a mountain of gypsum.","answer":"In the wet process, ground phosphate rock is treated with sulfuric acid. That makes a dilute phosphoric acid and a solid by-product, gypsum, which is filtered out. The acid is then concentrated by evaporation. A pricier electric-furnace route gives the purer acid used in food and drink.","aka":["orthophosphoric acid","H3PO4"],"inputs":["phosphate-rock","sulfuric-acid","coke","silica-sand"],"uses":["cola","soda"],"grounds":["phosphate-rock","silica-sand","sulfur","air","water","coal"],"upstreamSlugs":["phosphate-rock","sulfuric-acid","coke","silica-sand","sulfur","air","water","coal"],"downstreamSlugs":["cola","soda"],"steps":[{"name":"Grind the phosphate rock","process":"crush","text":"Phosphate minerals such as fluorapatite are ground fine so the acid can reach them.","inputs":["phosphate-rock"]},{"name":"Digest it in sulfuric acid","process":"react","text":"Sulfuric acid is added to the rock. It reacts to make phosphoric acid, calcium sulfate and some hydrogen fluoride gas.","inputs":["sulfuric-acid"]},{"name":"Filter off the gypsum","process":"separate","text":"The calcium sulfate, better known as gypsum, is filtered off. Phosphate gypsum can carry traces of radium, so it often cannot be used in construction.","inputs":[]},{"name":"Boil off water to concentrate","process":"cook","text":"The crude acid is 32 to 46 percent H3PO4. Evaporation lifts it to merchant grade at 75 to 85 percent.","inputs":[],"spec":"75 to 85% H3PO4"},{"name":"Or reduce rock in a furnace","process":"melt","text":"For food-grade acid, phosphate ore is reduced with coke in an electric arc furnace to give elemental phosphorus. The phosphorus is burned and dissolved in water to make a purer acid.","inputs":["coke","silica-sand"]}],"facts":["Phosphoric acid is rarely sold stronger than 85 percent, a grade that freezes at 21 °C.","The wet process is the most common way to make phosphoric acid for fertilizer.","The hydrogen fluoride by-product can be scrubbed with water to make hydrofluoric acid."],"where":[],"whereNote":null,"sources":[{"title":"Phosphoric acid","url":"https://en.wikipedia.org/wiki/Phosphoric_acid"},{"title":"Hydrofluoric acid","url":"https://en.wikipedia.org/wiki/Hydrofluoric_acid"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"photoresist","name":"Photoresist","kind":"material","category":"electronics","title":"How photoresist is made","url":"https://assemblyline.org/make/photoresist","stations":6,"upstream":14,"downstream":51,"depth":7,"dek":"Photoresist is a liquid that hardens or dissolves where light hits it, and that lets chips be drawn with light.","answer":"Conventional photoresist has three parts: a resin binder, a photoactive sensitizer and a solvent that keeps it liquid. Makers prepare and refine the resin, dissolve each component in solvent, and combine the solutions in a mixing vessel. The raw liquid then passes through fine plastic filters, sometimes twice, because stray particles and by-products leave defects in the printed pattern.","aka":["resist","photolithography resist"],"inputs":["phenolic-resin"],"uses":["microchip","memory-chip","printed-circuit-board","lcd-screen","indium-tin-oxide","compact-disc"],"grounds":["air","water","crude-oil","natural-gas","coal"],"upstreamSlugs":["phenolic-resin","phenol","formaldehyde","benzene","propylene","air","methanol","water","naphtha","hydrogen","toluene","crude-oil","natural-gas","coal"],"downstreamSlugs":["microchip","memory-chip","printed-circuit-board","lcd-screen","indium-tin-oxide","compact-disc","hearing-aid","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","rocket","smartwatch","wireless-earbuds","phone-charger","usb-cable","digital-camera","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","led-bulb","ev-battery","hard-drive","wind-turbine","microwave-oven","washing-machine","car","airplane","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","smoke-detector","oled-screen","skyscraper"],"steps":[{"name":"Prepare the resin","process":"react","text":"Resists for g-line and i-line lithography use novolak, a resin made by condensing phenols or cresols with formaldehyde. Far-ultraviolet resists use polymers with groups that an acid can cleave off.","inputs":["phenolic-resin"]},{"name":"Refine the crude polymer","process":"separate","text":"Unwanted short and overlong chains left over from polymerization cause scum and bridging in the final pattern. One patent dissolves the crude resin at a lower strength than the finished resist uses, then filters it to remove them.","inputs":[]},{"name":"Dissolve each component","process":"mix","text":"Resin goes into one portion of solvent and the light-sensitive agent into another. Far-ultraviolet types carry an acid generator and a quencher instead. Solvents named in one patent include ethyl lactate and 2-heptanone.","inputs":[]},{"name":"Combine in a mixing vessel","process":"mix","text":"The separate solutions run through their own valves into one vessel and are mixed until uniform. A patent diagram shows this as the first stage of the production apparatus.","inputs":[]},{"name":"Filter out fine particles","process":"separate","text":"Filters of fluorine-based resin or polyolefin catch the particles, with pores of roughly 0.01 to 1 µm. Some lines hold the liquid in a tank between two filter stages. Clogging is the running cost, so one patent back-washes filters with solvent.","inputs":[]},{"name":"Wash down between batches","process":"wash","text":"Using the same equipment for the next batch risks carrying over components and raising particle counts. One patent rinses with the resist solvent, a different solvent able to dissolve the residue, then the resist solvent again.","inputs":[]}],"facts":["A positive photoresist is weakened by light and a negative one is toughened by it.","Photoresist is used in photoengraving as well as chip photolithography."],"where":[],"whereNote":null,"sources":[{"title":"Photoresist","url":"https://en.wikipedia.org/wiki/Photoresist"},{"title":"US7264912B2, Method of producing photoresist","url":"https://patents.google.com/patent/US7264912"},{"title":"US7276575, Process for refining crude resin for resist","url":"https://patents.google.com/patent/US7276575"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"piano","name":"Piano","kind":"product","category":"play","title":"How pianos are made","url":"https://assemblyline.org/make/piano","stations":8,"upstream":51,"downstream":0,"depth":8,"dek":"The strings of a piano pull on its iron frame with more than 20 tons of force.","answer":"A piano is a wooden case holding a cast-iron frame, a spruce soundboard, and steel strings struck by felt hammers. Makers bend the wooden rim, cast the iron plate, string the frame under heavy tension, and build 88 keys with a lever action. Voicing and tuning take as long as the building.","aka":["grand piano","upright piano","pianoforte"],"inputs":["lumber","adhesive","timber","pig-iron","steel-wire","copper-wire","fleece"],"uses":[],"grounds":["timber","fleece","water","iron-ore","limestone","air","crude-oil","coal","copper-ore","natural-gas","sulfur","rock-salt","dolomite","manganese-ore","quartz"],"upstreamSlugs":["lumber","adhesive","timber","pig-iron","steel-wire","copper-wire","fleece","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","iron-ore","coke","limestone","air","steel","copper","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","coal","magnesium","steel-scrap","oxygen","lime","manganese","argon","copper-ore","naphtha","natural-gas","sulfur","benzene","rock-salt","dolomite","silicon","propane","manganese-ore","toluene","quartz","charcoal"],"downstreamSlugs":[],"steps":[{"name":"Bend the case","process":"laminate","text":"Layers of hardwood are glued and clamped round a form, giving the piano its curved outer rim. The wood is thick because the case has to take the pull of the strings.","inputs":["lumber","adhesive"]},{"name":"Build the soundboard","process":"assemble","text":"Thin boards of spruce are glued edge to edge into a large panel and ribbed underneath. Vibration from the strings crosses a bridge to this panel, which moves enough air to be heard.","inputs":["timber","adhesive"]},{"name":"Cast the iron plate","process":"cast","text":"Molten iron is poured into a sand mold to make the plate, a single massive frame. It sits above the soundboard and takes most of the strings' pull.","inputs":["pig-iron"]},{"name":"Wind the strings","process":"draw","text":"Steel wire is drawn to size for the high notes. Bass strings are wrapped with copper wire to make them heavy enough to sound low. Most notes use three strings.","inputs":["steel-wire","copper-wire"]},{"name":"Press the hammer felt","process":"press","text":"Wool felt is pressed over wooden hammer cores. Felt, first used in pianos by Jean-Henri Pape in 1826, hits the string cleanly and then falls away.","inputs":["fleece"]},{"name":"Make keys and action","process":"assemble","text":"Eighty-eight keys are cut and mounted on balance pivots. Each key moves a chain of levers that throws a hammer at the string and lets it fall back. A damper stops the string when the key is released.","inputs":["lumber"]},{"name":"String the frame","process":"assemble","text":"The plate is set into the case over the soundboard. Strings are threaded over the bridge, round pins in the plate and onto tuning pins, then hauled up to rough pitch.","inputs":[]},{"name":"Voice and tune","process":"inspect","text":"A technician tunes every string and works on the hammer felt with needles to even out the tone from note to note. The tuning settles for weeks after.","inputs":[]}],"facts":["Pianos can have over 12,000 individual parts.","Modern pianos have 88 keys, with the exception of Bosendorfer and Stuart & Sons models.","Cristofori's piano, invented around 1700, let players change loudness by touch. Its name was originally fortepiano."],"where":[],"whereNote":null,"sources":[{"title":"Piano","url":"https://en.wikipedia.org/wiki/Piano"},{"title":"Piano action","url":"https://en.wikipedia.org/wiki/Piano_action"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pickles","name":"Pickles","kind":"product","category":"food","title":"How pickles are made","url":"https://assemblyline.org/make/pickles","stations":6,"upstream":32,"downstream":0,"depth":7,"dek":"The sour in a fermented pickle comes from bacteria that live on the skin of the growing cucumber.","answer":"Cucumbers are washed and sorted, then packed into jars or tanks and covered with brine or a vinegar solution with spices. In a brine pickle, bacteria on the skin turn the sugars sour over days. In a vinegar pickle, acid does the work at once. Jars are then heat-sealed for the shelf.","aka":["pickled cucumber","gherkins","dill pickles"],"inputs":["cucumber","table-salt","water","mustard-seed","vinegar","sugar","glass-jar"],"uses":[],"grounds":["cucumber","water","mustard-seed","rock-salt","seawater","grapes","sugarcane","sugar-beet","corn","barley","limestone","silica-sand","natural-gas","trona","crude-oil","air"],"upstreamSlugs":["cucumber","table-salt","water","mustard-seed","vinegar","sugar","glass-jar","rock-salt","seawater","grapes","ethanol","malted-barley","yeast","sugarcane","sugar-beet","lime","glass","corn","ethylene","barley","molasses","limestone","silica-sand","soda-ash","naphtha","natural-gas","ammonia","carbon-dioxide","trona","crude-oil","hydrogen","air"],"downstreamSlugs":[],"steps":[{"name":"Wash and sort the cucumbers","process":"wash","text":"Small cucumbers are washed and graded by size. The bacteria that do the souring live on the skin of a growing cucumber, though commercial washing and packing can strip them off.","inputs":["cucumber"]},{"name":"Cover with brine","process":"mix","text":"Cucumbers are packed in containers and covered with salty water, usually 20 to 40 grams of salt per liter. Garlic, dill and other antimicrobial spices such as mustard seed often go in with them.","inputs":["table-salt","water","mustard-seed"],"spec":"20 to 40 g of salt per liter"},{"name":"Let bacteria sour them","process":"ferment","text":"Lactic acid bacteria multiply in the brine and turn the cucumber's own sugars into acid. A full-sour pickle sits in the brine long enough to ferment fully. A half-sour comes out sooner, still bright green and crisp.","inputs":[]},{"name":"Switch to vinegar","process":"mix","text":"Many commercial pickles skip the long fermentation. They are packed in a vinegar solution instead, sometimes with sugar and spices, as in bread-and-butter pickles. The acid starts preserving the cucumber at once.","inputs":["vinegar","sugar"]},{"name":"Jar the pickles","process":"fill","text":"Pickles go into glass jars with their liquid. Pickles were once stored in wooden barrels, but they are now sold in glass.","inputs":["glass-jar"]},{"name":"Heat and seal","process":"pasteurize","text":"A pickling solution is acidic enough, at pH 4.6 or lower, to stop enzymes and microbes. Heating the sealed jar adds a safety margin and keeps the pickles for months.","inputs":[],"spec":"pH 4.6 or lower"}],"facts":["Cucumbers were being pickled in the Tigris Valley around 2030 BCE.","A kosher dill is not necessarily kosher by religious law. The name describes a New York style heavy on garlic and dill.","The bubbly film that forms on top of a fermented brine does not mean the pickles have spoiled, and it can be removed."],"where":[],"whereNote":null,"sources":[{"title":"Pickling","url":"https://en.wikipedia.org/wiki/Pickling"},{"title":"Pickled cucumber","url":"https://en.wikipedia.org/wiki/Pickled_cucumber"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pig-iron","name":"Pig iron","kind":"material","category":"metals","title":"How pig iron is made","url":"https://assemblyline.org/make/pig-iron","stations":6,"upstream":5,"downstream":158,"depth":2,"dek":"Pig iron is named after piglets feeding at a sow, because that is what its sand molds looked like.","answer":"Pig iron is made in a blast furnace. Iron ore, coke and limestone drop in from the top while hot air roars in near the bottom. Carbon monoxide strips the oxygen from the ore, the limestone gathers the rock into slag, and molten iron with 3.8 to 4.7 percent carbon collects in the hearth, ready to be tapped.","aka":["hot metal","blast furnace iron","crude iron"],"inputs":["iron-ore","coke","limestone","air"],"uses":["steel","cast-iron-pan","car-engine","piano","dumbbell","sailboat"],"grounds":["iron-ore","limestone","air","coal"],"upstreamSlugs":["iron-ore","coke","limestone","air","coal"],"downstreamSlugs":["steel","cast-iron-pan","car-engine","piano","dumbbell","sailboat","toothbrush","lithium-ion-cell","ev-battery","aa-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","inkjet-printer","electric-toothbrush","car","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-car","refrigerator","microwave-oven","washing-machine","blender","air-conditioner","treadmill","game-console","graphics-card","phone-charger","safety-pin","airbag","ceiling-fan","water-heater","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","concrete","skyscraper","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","action-figure","power-outlet","champagne","electric-kettle","pencil","mirror","golf-ball","wallpaper","wooden-chair","water-bottle","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","snow-globe","neon-sign","aluminum-window-frame","toffee"],"steps":[{"name":"Charge the stack","process":"fill","text":"Iron ore, coke and limestone are fed in at the top of the furnace, and the stack runs without stopping for long periods. Furnaces are hard to start and stop, so they are kept going. The coke must stay strong, because the column has to stay porous for gas to rise through it.","inputs":["iron-ore","coke","limestone"]},{"name":"Blast in hot air","process":"react","text":"Pipes called tuyeres blow preheated air, sometimes enriched with oxygen, into the lower furnace. The air burns the coke and makes hot carbon monoxide, which is the real worker in the process.","inputs":["air"]},{"name":"Strip the oxygen off the ore","process":"melt","text":"As ore sinks, the carbon monoxide rising through it takes oxygen away in stages. Near the top, at 200 to 700 °C, the oxide is partly reduced. Around 850 °C it is reduced further, and by the lower furnace, at up to 1,200 °C, iron metal forms. This countercurrent flow is why the furnace is efficient.","inputs":[],"spec":"up to 1,200 °C"},{"name":"Float off the rock as slag","process":"refine","text":"The heat breaks limestone into lime, and the lime combines with silica from the ore to form silicates. These float on the iron as molten slag, which carries away much of the rock that came in with the ore.","inputs":[]},{"name":"Tap iron and slag","process":"separate","text":"At intervals the furnace is opened at the bottom and a stream of molten iron runs out, with the lighter slag skimmed from its surface. The iron is saturated with carbon, around 4 to 5 percent, which makes it brittle.","inputs":[]},{"name":"Ladle it or cast the pigs","process":"cast","text":"Most iron goes still liquid, in ladle cars, to a steel plant next door. The rest runs onto a pig-casting machine, which makes sticks that snap into pieces of 4 to 10 kilograms. The old way was a sand bed with a main channel feeding many small molds.","inputs":[]}],"facts":["Pig iron was being made in China by the later Zhou dynasty, which ended in 256 BC.","Blast furnaces run without a pause for long periods, because they are difficult to start and stop.","Blast furnaces are estimated to have caused over 4 percent of global greenhouse gas emissions between 1900 and 2015."],"where":[],"whereNote":null,"sources":[{"title":"Pig iron","url":"https://en.wikipedia.org/wiki/Pig_iron"},{"title":"Blast furnace","url":"https://en.wikipedia.org/wiki/Blast_furnace"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pigment","name":"Pigment","kind":"material","category":"chemicals","title":"How pigments are made","url":"https://assemblyline.org/make/pigment","stations":8,"upstream":14,"downstream":182,"depth":4,"dek":"People were grinding color 350,000 years ago. Titanium dioxide now goes into about two-thirds of all pigments.","answer":"Pigment plants make colored powders that will not dissolve. Red iron oxide mostly comes from two routes, Laux and Penniman. Organic colors leave synthesis as coarse crude crystals that need milling and finishing with water, solvents, acids or alkalis. Fine grinding sets how well the powder spreads, and each lot is tested against a standard before sale to paint, ink and plastic makers.","aka":["colorant","color pigment","paint pigment"],"inputs":["iron-ore","titanium-dioxide","carbon-black","sulfur"],"uses":["toothbrush","lipstick","nail-polish","mascara","pvc","abs-plastic","ink","paint","lego-brick","lcd-screen","porcelain","chalk","candy-cane","sprinkles","crayon","plastic-straw","pencil-eraser","printer-toner","billiard-ball","foundation-makeup","eyeshadow","eyeglass-frame","towel"],"grounds":["iron-ore","sulfur","titanium-ore","crude-oil","air","water","rock-salt","coal"],"upstreamSlugs":["iron-ore","titanium-dioxide","carbon-black","sulfur","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","crude-oil","air","water","rock-salt","coal"],"downstreamSlugs":["toothbrush","lipstick","nail-polish","mascara","pvc","abs-plastic","ink","paint","lego-brick","lcd-screen","porcelain","chalk","candy-cane","sprinkles","crayon","plastic-straw","pencil-eraser","printer-toner","billiard-ball","foundation-makeup","eyeshadow","eyeglass-frame","towel","credit-card","plastic-wrap","dishwasher","garden-hose","football","volleyball","yoga-mat","action-figure","fashion-doll","globe","inflatable-pool-toy","chain-link-fence","pvc-pipe","vinyl-floor","power-cable","smoke-detector","flip-flops","usb-cable","vinyl-record","hearing-aid","thermometer","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","ballpoint-pen","snowboard","harmonica","suitcase","high-heels","wireless-earbuds","phone-charger","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","syringe","plastic-bag","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","frisbee","board-game","jigsaw-puzzle","trading-cards","candy-coated-chocolate","floor-tile","underwear","flag","compact-disc","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","scissors","mirror","car","electric-car","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","dartboard","dice","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","smartwatch","digital-camera","donut","aa-battery","popcorn","vacuum-cleaner","cotton-candy","pillow","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","soap","toothpaste","detergent","nitrile-glove","paperclip","corn-flakes","fireworks","candle","salsa","fish-sticks","zip-bag","blender","cotton-swab","mouthwash","cough-syrup","light-switch","facial-tissue","envelope","padlock","toffee"],"steps":[{"name":"Dig the earth colors","process":"mine","text":"Iron oxide minerals give red and yellow ochre, the oldest colors people have used. Iron-rich earth is dug, cleaned and sorted before any processing.","inputs":["iron-ore"]},{"name":"Bring in white and black","process":"mix","text":"Two pigments make up a huge share of the market and have lines of their own. Titanium dioxide gives white and opacity, and carbon black gives the darkest tones.","inputs":["titanium-dioxide","carbon-black"]},{"name":"React iron into reds","process":"react","text":"The Laux and Penniman processes together meet more than 90% of demand for synthetic red iron oxide. Laux oxidizes iron with aromatic nitro compounds and forms its reds by calcining. Penniman can give very bright reds with a yellow undertone.","inputs":[]},{"name":"Synthesize the bright colors","process":"react","text":"Chemical reactions build colors nature supplies poorly. Ultramarine, once made from lapis lazuli, is made by treating aluminum silicate with sulfur. Phthalo blue is a metal and organic compound created in the early 20th century.","inputs":["sulfur"]},{"name":"Mill the crude crystals","process":"grind","text":"Many organic colors come out of synthesis coarse and crystalline. Patents describe dry milling, sometimes with salt, often followed by wet milling in a stirred ball mill with very small grinding media.","inputs":[]},{"name":"Finish the color","process":"wash","text":"A later treatment using water, solvents, or weak acids and alkalis turns crude crystals into the usable pigment form. Any milling salts have to be extracted, which leaves waste water to deal with.","inputs":[]},{"name":"Micronize the powder","process":"grind","text":"Downstream grinding raises the share of primary particles, so the pigment stirs into liquids more easily. Bayer introduced this micronization in Germany in 1964.","inputs":[]},{"name":"Test against standards","process":"inspect","text":"Each batch is checked by general ISO test methods for pigments and dispersion. Makers identify the color by a Colour Index number, so buyers can get the same chemical whatever the trade name.","inputs":[]}],"facts":["Prussian blue, the oldest modern synthetic color, turned up by accident in 1704.","The Colour Index catalogs over 27,000 products under over 13,000 generic names.","Egyptian blue, the first known synthetic pigment, dates to around 3250 BC."],"where":[],"whereNote":null,"sources":[{"title":"US5626662A, Fine division in the preparation of organic pigments","url":"https://patents.google.com/patent/US5626662/en"},{"title":"US6086846A, Use of synthetic iron raw materials for preparing iron oxide pigments","url":"https://patents.google.com/patent/US6086846/en"},{"title":"Minimal Eco Impact, Maximal Color Effect, Palmer Holland","url":"https://www.palmerholland.com/news-and-insights/minimal-eco-impact-maximal-color-effect"},{"title":"Pigment","url":"https://en.wikipedia.org/wiki/Pigment"},{"title":"Titanium dioxide","url":"https://en.wikipedia.org/wiki/Titanium_dioxide"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pigs","name":"Pigs","kind":"raw","category":"farm","title":"How pigs are raised","url":"https://assemblyline.org/make/pigs","stations":4,"upstream":0,"downstream":17,"depth":0,"dek":"A piglet fights for a particular teat in its first hours, and keeps feeding from the same one.","answer":"Pigs are raised mostly on intensive farms, where thousands live in climate-controlled buildings. A sow farrows a litter, and piglets nurse about every 50 to 60 minutes. They are then fed until they reach market weight. Free-range and outdoor systems exist, but intensive units raise most of the pigs.","aka":["hog farming","pig farming","swine","pork production","hogs"],"inputs":[],"uses":["gelatin","hot-dog","bacon","sausage","salami","ham","canned-meat","sausage-casing"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["gelatin","hot-dog","bacon","sausage","salami","ham","canned-meat","sausage-casing","yogurt","gummy-bears","marshmallow","wine","gelatin-dessert","gelatin-capsule","banknote","frozen-pizza","champagne"],"steps":[{"name":"Breed the sows","process":"grow","text":"Females reach sexual maturity at 3 to 12 months and come into heat every 18 to 24 days until they are bred. A sow builds a nest during the final 24 hours before farrowing, which is giving birth to a litter.","inputs":[]},{"name":"Nurse the litter","process":"grow","text":"Piglets are born precocious with sharp teeth and fight for the front teats, which give more milk. Nursing happens about every 50 to 60 minutes, and each piglet keeps feeding from the same teat or small group of them.","inputs":[]},{"name":"Fatten in the barn","process":"grow","text":"On intensive farms, commercial units house thousands of pigs in climate-controlled buildings. Pigs convert feed to meat more efficiently than cattle do, which helps keep pork cheaper.","inputs":[]},{"name":"Send to slaughter","process":"harvest","text":"More than one billion pigs are butchered each year worldwide, 100 million of them in the United States. They supply pork, bacon and ham, and the skin is used for leather.","inputs":[]}],"facts":["Around 1.5 billion pigs are raised each year, producing some 120 million tonnes of meat.","Pigs have 1,113 genes for smell receptors, compared to 1,094 in dogs, and in Europe trained pigs find underground truffles."],"where":[],"whereNote":null,"sources":[{"title":"Domestic pig","url":"https://en.wikipedia.org/wiki/Domestic_pig"},{"title":"Pig farming","url":"https://en.wikipedia.org/wiki/Pig_farming"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pillow","name":"Pillow","kind":"product","category":"textiles","title":"How pillows are made","url":"https://assemblyline.org/make/pillow","stations":6,"upstream":66,"downstream":0,"depth":11,"dek":"Pillow fiber is combed fluffy and blown into the case by a machine that can fill about 100 pillows an hour.","answer":"Cotton or cotton-polyester fabric is cut dozens of layers at a time and sewn into cases with one edge left open. A machine combs bales of polyester fiber until fluffy and blows it into each case through a tube. Workers sew the opening shut, each pillow is weighed, and a machine slips it into a plastic bag.","aka":["bed pillow","polyester pillow"],"inputs":["cotton-fabric","thread","polyester","plastic-bag","cardboard-box"],"uses":[],"grounds":["water","raw-cotton","corn","natural-gas","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","sugarcane","timber","limestone","rock-salt","coal","sugar-beet"],"upstreamSlugs":["cotton-fabric","thread","polyester","plastic-bag","cardboard-box","cotton-yarn","corn-starch","water","pet-plastic","polyethylene","ink","cardboard","adhesive","raw-cotton","corn","p-xylene","ethylene","ethylene-glycol","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","wood-pulp","acrylic","epoxy","polyurethane","paraffin-wax","naphtha","natural-gas","oxygen","carbon-dioxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","sugarcane","yeast","timber","caustic-soda","lime","hydrogen-peroxide","propylene","ammonia","methanol","acetone","nitric-acid","hydrogen","limestone","benzene","rock-salt","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the cover fabric","process":"cut","text":"Sturdy cotton or cotton-polyester fabric arrives in huge bolts. Stacks of dozens of layers are cut at once with heavy shears or cutting machines.","inputs":["cotton-fabric"]},{"name":"Sew the case","process":"sew","text":"An operator sews two rectangles together around the edges, leaving a gap of around 15 centimeters. The tag listing the contents is stitched in, and the case is turned inside out so the seams are hidden.","inputs":["thread"]},{"name":"Comb the fiber fluffy","process":"separate","text":"A whole bale of polyester, about 272 kg, is fed into a machine that opens and combs it so the fibers have loft.","inputs":["polyester"]},{"name":"Blow in the filling","process":"fill","text":"The open edge of the case is slipped over a tube and a blower pushes the fluffy fiber in. Some machines can fill up to 100 pillows an hour.","inputs":[]},{"name":"Sew it shut and weigh","process":"sew","text":"Workers close the opening on an industrial sewing machine, then weigh the pillow to check it holds the amount of fill on its label.","inputs":["thread"]},{"name":"Bag and box","process":"package","text":"A machine blows air into thin plastic bags to open them and slides one pillow into each. The bagged pillows go into cartons.","inputs":["plastic-bag","cardboard-box"]}],"facts":["A small to medium pillow plant makes between 2,000 and 3,500 pillows a day, and the largest American makers make 10,000 to 15,000.","The cover fabric is calendered, pressed smooth between rollers, so the sewn case can be blown open and separated easily during filling."],"where":[],"whereNote":null,"sources":[{"title":"Pillow","url":"https://encyclopedia.com/manufacturing/news-wires-white-papers-and-books/pillow"},{"title":"Pillow","url":"https://en.wikipedia.org/wiki/Pillow"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pinball-machine","name":"Pinball machine","kind":"product","category":"play","title":"How pinball machines are made","url":"https://assemblyline.org/make/pinball-machine","stations":7,"upstream":66,"downstream":0,"depth":9,"dek":"A pinball machine has about 3,500 parts and 400 to 800 meters of wire, wired by hand.","answer":"A modern pinball machine is built from about 3,500 parts. Incoming parts are sample-inspected, and workers hand-make a wiring bundle that runs 400 to 800 meters. Cabinets get artwork decals applied with soapy water. Mechanisms are built and tested, mounted on a playfield, and the playfield drops into the cabinet for final testing.","aka":["pinball","pin table","flipper machine"],"inputs":["copper-wire","plywood","adhesive","printed-circuit-board","led"],"uses":[],"grounds":["timber","water","copper-ore","air","crude-oil","silica-sand","limestone","bauxite","zinc-ore","natural-gas","gold-ore","sulfur","rock-salt","trona","tin-ore","lead-ore","silver-ore","corn","coal","sugarcane","sugar-beet"],"upstreamSlugs":["copper-wire","plywood","adhesive","printed-circuit-board","led","copper","timber","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","fiberglass","photoresist","solder","gallium","indium","ammonia","hydrogen","gold","plastic","copper-ore","oxygen","air","sulfuric-acid","ethylene","propylene","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","silica-sand","limestone","soda-ash","phenolic-resin","tin","lead","silver","bauxite","zinc-ore","natural-gas","gold-ore","lime","zinc","naphtha","sulfur","benzene","rock-salt","carbon-dioxide","trona","formaldehyde","tin-ore","coke","lead-ore","silver-ore","toluene","corn","yeast","coal","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Inspect incoming parts","process":"inspect","text":"About 3,500 parts arrive for each machine. A sample of 20 percent is checked, such as drop targets fitted into a gauge, and a batch is rejected if 3 percent of the sample is defective.","inputs":[]},{"name":"Build the wiring bundle","process":"assemble","text":"Workers hand-lay wire into a bundle of 400 to 800 meters in total length. It takes about 5 to 6 hours and every configuration is tested by hand.","inputs":["copper-wire"],"spec":"400 to 800 meters of wire"},{"name":"Apply the cabinet art","process":"coat","text":"Decals go on the traditionally wooden cabinet. A worker sprays soapy water so the decal can slide into place, then squeegees out the moisture.","inputs":["plywood","adhesive"]},{"name":"Build the mechanisms","process":"assemble","text":"Gimmicks such as loops with strong magnets and toys are put together and tested separately. Circuit boards drive the playfield's lights and effects.","inputs":["printed-circuit-board","led"]},{"name":"Populate the playfield","process":"assemble","text":"On a rotating stand, workers bolt rails, ball guides, posts and mechanisms onto a playfield of plywood. The huge wiring bundle is then connected to LEDs, circuit boards, coils and switches.","inputs":["plywood"]},{"name":"Test every coil","process":"inspect","text":"A computer diagnoses the machine and tells the technician what to fix. Coils, switches and lights are tested before the playfield is lowered into the cabinet.","inputs":[]},{"name":"Install, check and ship","process":"assemble","text":"The playfield goes in the cabinet and is checked again. A display screen sits in the backbox on modern machines. The machine is then cleaned and shipped.","inputs":[]}],"facts":["Coin-operated pinball began in the early 1930s with games like Baffle Ball and Ballyhoo.","Flippers were first added in 1947, on Gottlieb's Humpty Dumpty.","Stern Pinball claims 90 percent of the world pinball market, from one factory in suburban Chicago, and each machine takes about 30 hours to assemble."],"where":[],"whereNote":null,"sources":[{"title":"How are pinball machines made?","url":"https://gigazine.net/gsc_news/en/20180107-how-to-make-pinball-machine"},{"title":"Inside the world's largest pinball factory","url":"https://www.scrippsnews.com/us-news/inside-the-world-s-largest-pinball-factory-in-suburban-chicago"},{"title":"How Are Pinball Machines Built?","url":"https://www.neoteo.com/en/how-are-pinball-machines-built"},{"title":"Pinball","url":"https://en.wikipedia.org/wiki/Pinball"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pizza-box","name":"Pizza box","kind":"product","category":"wood-paper","title":"How pizza boxes are made","url":"https://assemblyline.org/make/pizza-box","stations":5,"upstream":55,"downstream":0,"depth":8,"dek":"A pizza box ships flat and folds without any glue, thanks to a cutting die that creases and slices in one stroke.","answer":"Corrugated board, a rippled paper sheet glued between flat layers, is printed and then fed to a die that cuts the outline, creases the folds and punches vent slots in one stroke. The flat blanks are stacked and shipped to the pizzeria, where staff fold the walls and flaps into a box.","aka":["pizza package","pizza carton"],"inputs":["paper","adhesive","ink"],"uses":[],"grounds":["water","kaolin","limestone","timber","crude-oil","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","natural-gas","coal","sugar-beet"],"upstreamSlugs":["paper","adhesive","ink","wood-pulp","water","kaolin","limestone","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","hydrogen","soybeans","rapeseed","hexane","clay","formaldehyde","air","titanium-ore","coke","iron-ore","sulfur","corn","sugarcane","yeast","rock-salt","naphtha","natural-gas","benzene","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Ripple the middle sheet","process":"press","text":"Paper passes between two heated, interlocking rolls that press it into waves called flutes. Pizza boxes often use fine E flutes, with a pitch of 1.0 to 1.8 millimeters.","inputs":["paper"],"spec":"E flute pitch 1.0 to 1.8 mm"},{"name":"Glue on the flat liners","process":"laminate","text":"Starch adhesive goes on the flute tips, and a flat paper liner is pressed onto each side under heat. A knife then cuts the moving board into sheets.","inputs":["paper","adhesive"]},{"name":"Print the outside","process":"print","text":"Flexible plates print the brand and instructions on the outer liner, one plate for each color.","inputs":["ink"]},{"name":"Cut, crease and slot","process":"stamp","text":"A steel-rule die presses down on each sheet, cutting the outline, creasing the fold lines and punching vent slots in the same motion. Robert Gair found the cut-and-crease trick by accident in 1890. The slots let steam out so the crust stays crisp.","inputs":[]},{"name":"Stack the flat blanks","process":"package","text":"Blanks are counted, stacked flat and strapped, which saves a great deal of truck space. Staff fold them into boxes at the shop, with no glue needed.","inputs":[]}],"facts":["Neapolitan pizza bakers once sent pizzas to street sellers in round metal containers called stufe, which means ovens.","The first patent for a corrugated pizza box, from 1963, already had flat blanks, glue-free folding and vent slots.","The little plastic stand in the middle of some pizzas is called a pizza saver, and it stops the lid from touching the cheese."],"where":[],"whereNote":null,"sources":[{"title":"Pizza box","url":"https://en.wikipedia.org/wiki/Pizza_box"},{"title":"Corrugated fiberboard","url":"https://en.wikipedia.org/wiki/Corrugated_fiberboard"},{"title":"How Corrugated Boxes Are Made: The Complete Manufacturing Guide","url":"https://www.corrugatednews.com/guides/how-corrugated-boxes-are-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"plaster","name":"Plaster of Paris","kind":"material","category":"minerals","title":"How plaster of Paris is made","url":"https://assemblyline.org/make/plaster","stations":5,"upstream":1,"downstream":2,"depth":1,"dek":"Plaster of Paris is gypsum cooked just hot enough to lose most of its water, so adding water brings it back to stone.","answer":"Plaster of Paris is made by heating gypsum to about 120 to 180 °C in a kiln. The mineral loses most of its bound water as steam and becomes a white powder. Mixed with water, the powder starts to set in about 10 minutes and is hard in about 45, as it returns to gypsum.","aka":["gypsum plaster","plaster","calcium sulfate hemihydrate"],"inputs":["gypsum"],"uses":["gold-ring","prosthetic-leg"],"grounds":["gypsum"],"upstreamSlugs":["gypsum"],"downstreamSlugs":["gold-ring","prosthetic-leg"],"steps":[{"name":"Quarry the gypsum","process":"mine","text":"Gypsum is a soft sulfate mineral found in thick evaporite beds. It is widely mined from open pits and underground workings.","inputs":["gypsum"]},{"name":"Crush the rock","process":"crush","text":"Quarried lumps are broken into small pieces so that heat can reach all the way through them.","inputs":[]},{"name":"Heat it gently in a kiln","process":"react","text":"Heated to about 120–180 °C, gypsum loses part of its water as steam and becomes calcium sulfate hemihydrate. Overheat it past 250 °C and it turns into dead-burned plaster, which no longer sets quickly.","inputs":[],"spec":"120–180 °C"},{"name":"Grind to a fine powder","process":"grind","text":"The cooked gypsum is ground into a white powder that dissolves and recrystallizes quickly when it meets water.","inputs":[]},{"name":"Seal it from moisture","process":"package","text":"Plaster is stored in moisture-proof containers, since even humid air starts to hydrate it slowly and ruins it.","inputs":[]}],"facts":["The name comes from a large gypsum deposit at Montmartre, a hill in the north end of Paris.","In ancient Egypt, burnt and crushed gypsum was mixed with water to make mortar between the blocks of pyramids.","Plaster expands slightly as it sets, which helps it fill every detail of a mold."],"where":[],"whereNote":null,"sources":[{"title":"Plaster","url":"https://en.wikipedia.org/wiki/Plaster_of_Paris"},{"title":"Gypsum","url":"https://en.wikipedia.org/wiki/Gypsum"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"plastic","name":"Plastic","kind":"material","category":"plastics","title":"How plastic is made","url":"https://assemblyline.org/make/plastic","stations":5,"upstream":7,"downstream":48,"depth":4,"dek":"Over 400 million metric tons of plastic were made in 2023, and more than half of all plastic ever produced came after 2004.","answer":"Plastic is made of long chain molecules called polymers, built by linking small repeating units called monomers. Plants make the monomers from oil or gas, join them into polymer, and add other ingredients. The product is melted into pellets, which factories mold, extrude or press into finished shapes.","aka":["polymer","plastics","synthetic resin"],"inputs":["naphtha","natural-gas","ethylene","propylene"],"uses":["duct-tape","led","aa-battery","solar-panel","refrigerator","washing-machine","vacuum-cleaner","nonstick-pan","marker-pen","highlighter","fountain-pen","printer-toner","toaster","roller-skates","tennis-racket","bowling-ball","dice","yo-yo","board-game","jigsaw-puzzle","trading-cards","globe","snow-globe","toy-car","tampon","wet-wipes","asthma-inhaler","prosthetic-leg","wheelchair","light-switch","power-outlet","smoke-detector","seat-belt","backpack","eyeglass-frame","microphone","e-reader","umbrella"],"grounds":["natural-gas","crude-oil","water"],"upstreamSlugs":["naphtha","natural-gas","ethylene","propylene","crude-oil","water","hydrogen"],"downstreamSlugs":["duct-tape","led","aa-battery","solar-panel","refrigerator","washing-machine","vacuum-cleaner","nonstick-pan","marker-pen","highlighter","fountain-pen","printer-toner","toaster","roller-skates","tennis-racket","bowling-ball","dice","yo-yo","board-game","jigsaw-puzzle","trading-cards","globe","snow-globe","toy-car","tampon","wet-wipes","asthma-inhaler","prosthetic-leg","wheelchair","light-switch","power-outlet","smoke-detector","seat-belt","backpack","eyeglass-frame","microphone","e-reader","umbrella","led-bulb","lcd-screen","television","computer-mouse","pinball-machine","remote-control","satellite","laptop","smartwatch","digital-camera"],"steps":[{"name":"Make the building blocks","process":"react","text":"Oil or natural gas is turned into small hydrocarbon molecules that can be strung together. Ethylene and propylene are the best known.","inputs":["naphtha","natural-gas"]},{"name":"Link them into chains","process":"react","text":"Monomers join into polymer chains of thousands of repeating units. The type of monomer decides which plastic comes out.","inputs":["ethylene","propylene"]},{"name":"Blend in additives","process":"mix","text":"Polymer is mixed with other ingredients that give it color, strength or flexibility. Most plastics are polymer plus additives.","inputs":[]},{"name":"Cut into pellets","process":"cut","text":"The melt is extruded in strands and chopped into small pellets. Pellets are easy to ship by the truckload.","inputs":[]},{"name":"Mold, extrude or press","process":"mold","text":"Factories reheat the pellets and form them into films, fibers, pipes, bottles and boxes. A thermoset, in contrast, can melt and take shape only once.","inputs":[]}],"facts":["About 9.2 billion metric tons of plastic were estimated to have been made between 1950 and 2017.","Roughly 80 percent of plastic is commodity plastic chosen for low cost.","Packaging takes about a third of all plastic."],"where":[],"whereNote":null,"sources":[{"title":"Plastic","url":"https://en.wikipedia.org/wiki/Plastic"},{"title":"Polystyrene","url":"https://en.wikipedia.org/wiki/Polystyrene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"plastic-bag","name":"Plastic bag","kind":"product","category":"plastics","title":"How plastic bags are made","url":"https://assemblyline.org/make/plastic-bag","stations":6,"upstream":55,"downstream":5,"depth":10,"dek":"A plastic bag starts as a tube of molten polyethylene, inflated into a bubble from a ring-shaped die.","answer":"Plastic bags are made by melting polyethylene pellets and extruding the melt upward through a ring-shaped die while air is blown in, which inflates a thin tube of film. The tube is cooled, flattened and rolled up. Another machine prints it, then heat seals and cuts it into individual bags.","aka":["polybag","carrier bag","grocery bag","poly bag"],"inputs":["polyethylene","ink","cardboard-box"],"uses":["syringe","vacuum-cleaner","electric-kettle","cotton-candy","pillow"],"grounds":["water","natural-gas","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","coal","timber","sugar-beet","limestone"],"upstreamSlugs":["polyethylene","ink","cardboard-box","ethylene","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","cardboard","adhesive","naphtha","natural-gas","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","wood-pulp","acrylic","epoxy","polyurethane","paraffin-wax","hydrogen","benzene","propylene","methanol","rock-salt","coal","molasses","timber","caustic-soda","lime","hydrogen-peroxide","ammonia","acetone","nitric-acid","toluene","sugar-beet","limestone"],"downstreamSlugs":["syringe","vacuum-cleaner","electric-kettle","cotton-candy","pillow"],"steps":[{"name":"Melt the pellets","process":"melt","text":"Pellets of high- or low-density polyethylene, made from natural gas or petroleum and increasingly mixed with recycled plastic, feed into an extruder. The choice of grade sets the bag's strength, clarity and thickness.","inputs":["polyethylene"]},{"name":"Blow a tube of film","process":"blow","text":"The melt is forced through a ring-shaped die as a continuous tube. Air inside inflates it into a bubble, stretching the plastic to the wanted width and gauge.","inputs":[]},{"name":"Cool and flatten","process":"chill","text":"An air ring chills the bubble as it rises. Once solid, the tube is collapsed flat and wound up for converting.","inputs":[]},{"name":"Print the film","process":"print","text":"Flexographic or gravure presses lay logos and text onto the film. This step is optional, and plain bags skip it.","inputs":["ink"]},{"name":"Seal and cut","process":"weld","text":"Converting machines cut the flattened film to length and heat seal the bottom of each piece. Handles can be cut in at this point.","inputs":[]},{"name":"Check and pack","process":"package","text":"Inspectors look at dimensions, seal strength and print quality. Bags that pass are packed tightly to save shipping space.","inputs":["cardboard-box"]}],"facts":["About 1 to 5 trillion plastic bags are used and discarded around the world every year.","In the late 1950s, Curt Lindquist, the CEO of Celloplast in Sweden, began experimenting with plastic, and a patent was awarded in 1965.","Bags can have gussets for extra volume, and stand-up pouches can stand on a shelf."],"where":[],"whereNote":null,"sources":[{"title":"Optima Bags: how plastic bags are manufactured","url":"https://optimabags.com/blogs/optima-manufacturing/how-are-plastic-bags-manufactured-step-by-step-process"},{"title":"Plastic bag","url":"https://en.wikipedia.org/wiki/Plastic_bag"},{"title":"Polyethylene","url":"https://en.wikipedia.org/wiki/Polyethylene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"plastic-bottle","name":"Plastic bottle","kind":"product","category":"plastics","title":"How plastic bottles are made","url":"https://assemblyline.org/make/plastic-bottle","stations":5,"upstream":18,"downstream":34,"depth":6,"dek":"A soda bottle begins as a clear plastic test tube the size of your finger, which is then inflated to bottle size.","answer":"A PET bottle is made in two steps. Dried PET chips are melted and injected into a mold to make a small, thick-walled tube called a preform, with the finished neck already formed. Later the preform is reheated, stretched with a rod and inflated by high-pressure air against a bottle-shaped mold.","aka":["PET bottle","soda bottle","water bottle"],"inputs":["pet-plastic"],"uses":["shampoo","sunscreen","aspirin","detergent","bleach","vitamin-c","ketchup","cola","sparkling-water","soda","dish-soap","hair-dye","foundation-makeup","mouthwash","cough-syrup"],"grounds":["natural-gas","water","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","water","oxygen","carbon-dioxide","crude-oil","hydrogen","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["shampoo","sunscreen","aspirin","detergent","bleach","vitamin-c","ketchup","cola","sparkling-water","soda","dish-soap","hair-dye","foundation-makeup","mouthwash","cough-syrup","kitchen-sponge","flour","bread","instant-noodles","tortilla","croissant","donut","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","fish-sticks","modeling-clay","licorice","cake-mix"],"steps":[{"name":"Dry the resin","process":"dry","text":"PET chips are dried in hot air, since even a little moisture would degrade the plastic when it melts. The dry chips go straight to the injection machine.","inputs":["pet-plastic"]},{"name":"Inject the preforms","process":"mold","text":"Melted PET is shot into a cooled mold, forming a clear tube with a closed end. The neck and thread are molded at full size, and they will not change shape later.","inputs":[]},{"name":"Reheat them to softness","process":"melt","text":"Preforms ride through an oven with infrared lamps. They soften until they are rubbery without melting, and the lamps are tuned to heat the walls evenly.","inputs":[]},{"name":"Stretch and blow","process":"blow","text":"A rod pushes the soft preform lengthwise as high-pressure air balloons it into a bottle-shaped mold. Stretching in both directions lines up the molecules and strengthens the walls.","inputs":[]},{"name":"Test every bottle","process":"inspect","text":"Cameras and sensors check wall thickness, clarity and neck dimensions. Bottles that fail go back to be recycled.","inputs":[]}],"facts":["Plastic bottles were first used commercially in 1947 but remained impractical until the 1970s, when the PET bottle was introduced.","The 28 mm PET bottle neck finish used for almost all PET beverage bottles worldwide was standardized as PCO 1881, with the guideline finalized in 2009.","PET gives very good barrier properties against alcohol and essential oils, along with a high degree of impact resistance."],"where":[],"whereNote":null,"sources":[{"title":"Plastic bottle","url":"https://en.wikipedia.org/wiki/Plastic_bottle"},{"title":"Blow molding","url":"https://en.wikipedia.org/wiki/Blow_molding"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"plastic-straw","name":"Plastic straw","kind":"product","category":"plastics","title":"How plastic straws are made","url":"https://assemblyline.org/make/plastic-straw","stations":7,"upstream":28,"downstream":0,"depth":5,"dek":"A plastic straw is a continuous tube of polypropylene chopped into lengths.","answer":"Polypropylene resin is melted together with color and stabilizers, cut into pellets, and fed to a second extruder fitted with a die shaped like a ring. The melt comes out as a continuous hollow tube. A puller draws it along, a water bath sets its shape, and a knife chops it into straws.","aka":["drinking straw","plastic drinking straw"],"inputs":["polypropylene","pigment","paper"],"uses":[],"grounds":["iron-ore","sulfur","water","kaolin","limestone","crude-oil","titanium-ore","air","timber","rock-salt","coal","natural-gas"],"upstreamSlugs":["polypropylene","pigment","paper","propylene","iron-ore","titanium-dioxide","carbon-black","sulfur","wood-pulp","water","kaolin","limestone","naphtha","crude-oil","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","air","timber","caustic-soda","lime","hydrogen-peroxide","hydrogen","rock-salt","coal","natural-gas"],"downstreamSlugs":[],"steps":[{"name":"Blend resin and color","process":"mix","text":"Polypropylene is mixed with colorants and additives that resist oxidation and sunlight. Only a small amount of pigment gives a bright, even color.","inputs":["polypropylene","pigment"]},{"name":"Pelletize the melt","process":"cut","text":"The blend leaves the compounding barrel as thin strands, which are cooled and chopped into pellets, then dried and stored.","inputs":[]},{"name":"Extrude the hollow tube","process":"extrude","text":"Pellets melt in a second extruder and are forced through a ring-shaped die. A puller draws the soft tube along, and metal sizing plates keep its diameter even.","inputs":[]},{"name":"Cool over a water bath","process":"chill","text":"The tube passes through water or over a chilled rod so the inside dimension is fixed before it hardens.","inputs":[]},{"name":"Chop to length","process":"cut","text":"A knife assembly cuts the moving tube into straws.","inputs":[]},{"name":"Crimp the bendy part","process":"mold","text":"Bendable straws get extra processing after cutting. Special equipment presses a ring of grooves into the tube so it can fold without collapsing.","inputs":[]},{"name":"Wrap and box","process":"package","text":"Many straws are sealed in paper sleeves and bundled into boxes.","inputs":["paper"]}],"facts":["Straws were mostly paper until the 1960s, when polypropylene took over.","Rejected straws are ground up and remelted, because polypropylene can be melted again and again.","The oldest known straws are from the 3rd millennium BCE, made by Sumerians to drink beer."],"where":[],"whereNote":null,"sources":[{"title":"From Paper to Polypropylene: The Modern Manufacturing of Drinking Straws","url":"https://www.mfgrobots.com/Article/mfg/mpm/2315.html"},{"title":"Drinking straw","url":"https://en.wikipedia.org/wiki/Drinking_straw"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"plastic-wrap","name":"Plastic wrap","kind":"product","category":"plastics","title":"How plastic wrap is made","url":"https://assemblyline.org/make/plastic-wrap","stations":6,"upstream":42,"downstream":3,"depth":9,"dek":"Plastic wrap clings to smooth surfaces with no glue at all, using a film only about 10 micrometers thick.","answer":"Plastic wrap is a plastic resin, most often PVC or polyethylene, melted and pushed through a die into an extremely thin film. The film is cooled, stretched to thickness, slit to width and wound onto cardboard tubes. It sticks to smooth surfaces by itself, so no adhesive is needed.","aka":["cling film","cling wrap","food wrap","Saran wrap"],"inputs":["pvc","polyethylene","cardboard"],"uses":["aa-battery","popcorn","candy-cane"],"grounds":["water","natural-gas","rock-salt","iron-ore","sulfur","air","timber","crude-oil","titanium-ore","limestone","coal"],"upstreamSlugs":["pvc","polyethylene","cardboard","ethylene","chlorine","water","pigment","plasticizer","wood-pulp","adhesive","naphtha","natural-gas","rock-salt","sulfuric-acid","iron-ore","titanium-dioxide","carbon-black","sulfur","air","propylene","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","acrylic","epoxy","polyurethane","paraffin-wax","crude-oil","hydrogen","titanium-ore","coke","limestone","ammonia","methanol","phenol","acetone","nitric-acid","coal","benzene","toluene"],"downstreamSlugs":["aa-battery","popcorn","candy-cane"],"steps":[{"name":"Blend the resin","process":"mix","text":"PVC resin is mixed with plasticizers that make it soft and clingy. Cheaper wraps start from low-density polyethylene instead, often with a second polyethylene added to make it stick better and resist tearing.","inputs":["pvc","polyethylene"]},{"name":"Melt in the extruder","process":"melt","text":"Pellets feed into an extruder, where heat and the turning screw melt them into an even plastic melt.","inputs":[]},{"name":"Form the thin film","process":"extrude","text":"Cast lines push the melt through a flat die onto chilled rolls, and the fast cooling keeps the film clear. Blown lines push it through a ring die and inflate a bubble. PVC wrap is usually cast, and polyethylene wrap goes either way.","inputs":[]},{"name":"Stretch to thickness","process":"draw","text":"The film is stretched and gauged until it reaches its target thickness. Household wraps keep getting thinner because they need very little stretch in use.","inputs":[]},{"name":"Slit and wind","process":"cut","text":"Edges are trimmed and the wide film is slit to the width of a roll, then rewound onto cardboard cores.","inputs":["cardboard"]},{"name":"Box with a cutting edge","process":"package","text":"Each roll goes into a carton with a serrated edge that tears it to length.","inputs":["cardboard"]}],"facts":["Common plastic wrap is about 12.7 micrometers thick, and most brands on shelves are now 8, 9 or 10 micrometers.","Wrapping premature babies in plastic wrap right after birth has been studied as a way to keep them warm on the way to intensive care."],"where":[],"whereNote":null,"sources":[{"title":"Plastic wrap","url":"https://en.wikipedia.org/wiki/Plastic_wrap"},{"title":"Polyethylene","url":"https://en.wikipedia.org/wiki/Polyethylene"},{"title":"How Is Cling Film Made? Materials, Process and Quality Guide","url":"https://www.runhtape.com/blog/how-is-cling-film-made-materials-process-and-quality-guide.html"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"plasticizer","name":"Plasticizer","kind":"material","category":"chemicals","title":"How plasticizers are made","url":"https://assemblyline.org/make/plasticizer","stations":5,"upstream":7,"downstream":34,"depth":4,"dek":"Flexible vinyl can be up to 65% plasticizer by weight. Without it, PVC is hard and brittle.","answer":"Most are esters, oily liquids that wedge between plastic chains so they can slide. The commonest route starts with ortho-xylene, oxidized to phthalic anhydride, which then reacts with a branched alcohol such as 2-ethylhexanol. Excess alcohol is recovered and the finished liquid is shipped, and nearly all of it ends up softening PVC.","aka":["phthalate","DEHP","DOP","softener"],"inputs":["naphtha","air","propylene"],"uses":["nail-polish","pvc","pvb","yoga-mat","hairspray","vinyl-floor","cellulose-acetate"],"grounds":["air","crude-oil","water","natural-gas"],"upstreamSlugs":["naphtha","air","propylene","crude-oil","water","hydrogen","natural-gas"],"downstreamSlugs":["nail-polish","pvc","pvb","yoga-mat","hairspray","vinyl-floor","cellulose-acetate","credit-card","plastic-wrap","dishwasher","garden-hose","football","volleyball","action-figure","fashion-doll","globe","inflatable-pool-toy","chain-link-fence","pvc-pipe","power-cable","smoke-detector","flip-flops","usb-cable","vinyl-record","windshield","sunglasses","dice","shoelace","eyeglass-frame","aa-battery","popcorn","candy-cane","car","electric-car"],"steps":[{"name":"Separate the ortho-xylene","process":"refine","text":"Reforming naphtha gives a mix of aromatics, and this one isomer is split out. It has slowly displaced naphthalene as the feedstock, partly because it is easier to transport.","inputs":["naphtha"]},{"name":"Oxidize to phthalic anhydride","process":"react","text":"Vapor and air pass over a vanadium oxide catalyst. The product is a white solid, and its main use is exactly this one. About 3 million tonnes are made each year.","inputs":["air"]},{"name":"Bring in a branched alcohol","process":"react","text":"Plants make 2-ethylhexanol on a large scale from propylene. The branch in its chain carries over to the finished ester, helping to reduce viscosity and volatility.","inputs":["propylene"]},{"name":"Join acid and alcohol","process":"react","text":"Excess alcohol reacts with the anhydride under an acid catalyst such as sulfuric acid, giving a diester. The most important one is known as DEHP. Others use adipates, terephthalates and trimellitates in place of the phthalate.","inputs":[]},{"name":"Recover and drum","process":"refine","text":"Leftover alcohol is taken off for reuse, and the oily liquid is sent to compounders in bulk. They mix it into PVC, where it stays unbound to the chains. That is why it can slowly migrate out over the years.","inputs":[]}],"facts":["Flexible PVC holds 5% to 65% plasticizer by weight.","Almost 90% of polymer plasticizers are used in PVC.","The new car smell is often blamed on plasticizers, but studies do not find phthalates in it in appreciable amounts."],"where":[],"whereNote":null,"sources":[{"title":"Plasticizer","url":"https://en.wikipedia.org/wiki/Plasticizer"},{"title":"Phthalic anhydride","url":"https://en.wikipedia.org/wiki/Phthalic_anhydride"},{"title":"Bis(2-ethylhexyl) phthalate","url":"https://en.wikipedia.org/wiki/Bis(2-ethylhexyl)_phthalate"},{"title":"2-Ethylhexanol","url":"https://en.wikipedia.org/wiki/2-Ethylhexanol"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"platinum","name":"Platinum","kind":"material","category":"metals","title":"How platinum is made","url":"https://assemblyline.org/make/platinum","stations":6,"upstream":12,"downstream":1,"depth":4,"dek":"Platinum is so rare that the Sudbury mines in Canada process huge quantities of nickel ore that hold only 0.5 ppm of it.","answer":"Platinum is mostly won from rock layers in South Africa, and as a byproduct of nickel and copper mining. Ore is concentrated and smelted, leaving the platinum-group metals in a residue or anode mud. Refiners dissolve this in aqua regia, drop out the gold, precipitate platinum as a salt with ammonium chloride, and heat it to metal.","aka":["platinum metal","platinum-group metal"],"inputs":["platinum-ore","nitric-acid","hydrochloric-acid","ammonia"],"uses":["hard-drive"],"grounds":["platinum-ore","air","water","natural-gas","rock-salt","sulfur"],"upstreamSlugs":["platinum-ore","nitric-acid","hydrochloric-acid","ammonia","air","water","chlorine","hydrogen","natural-gas","rock-salt","sulfuric-acid","sulfur"],"downstreamSlugs":["hard-drive"],"steps":[{"name":"Mine the platinum reef","process":"mine","text":"Platinum averages about 5 micrograms per kilogram of Earth's crust. The Merensky Reef in South Africa's Bushveld Igneous Complex holds around 75 percent of the world's known platinum. Nickel and copper ores at Norilsk and Sudbury carry smaller amounts.","inputs":["platinum-ore"]},{"name":"Concentrate the metals","process":"separate","text":"The ore is crushed and concentrated so the sulfide minerals that carry platinum are gathered together. Typical platinum-group ores hold only about 10 grams of metal per ton of rock.","inputs":[]},{"name":"Smelt and strip the base metals","process":"melt","text":"Smelting and refining the nickel and copper leave the platinum-group metals behind. During copper electrorefining, they settle with silver and gold into an anode mud that is the starting point for recovery.","inputs":[]},{"name":"Dissolve it in aqua regia","process":"react","text":"The platinum-rich material is treated with aqua regia, a mixture of nitric and hydrochloric acids. Platinum, palladium and gold dissolve, while osmium, iridium, ruthenium and rhodium stay behind unreacted.","inputs":["nitric-acid","hydrochloric-acid"]},{"name":"Drop out gold, then platinum","process":"react","text":"Iron(II) chloride precipitates the gold, which is filtered off. Ammonium chloride is then added to the filtrate, and platinum comes out as ammonium chloroplatinate.","inputs":["ammonia"]},{"name":"Heat it to metal","process":"fire","text":"Heating the ammonium chloroplatinate drives off everything but the platinum, which remains as a metal sponge that can be melted and cast.","inputs":[]}],"facts":["The Sudbury Basin in Canada, one of the big platinum sources, is a meteorite impact site, and platinum turns up in higher amounts where such impacts set off volcanism.","Molten glass does not wet platinum, so the glass industry uses it to handle the melt.","In 1924 Hans Merensky found a large supply of platinum in the Bushveld Igneous Complex."],"where":[{"place":"South Africa","share":"about 71% of world mine production"},{"place":"Russia","share":"about 12%"}],"whereNote":"2025, platinum mine production, out of an estimated 170,000 kilograms.","sources":[{"title":"Platinum","url":"https://en.wikipedia.org/wiki/Platinum"},{"title":"Platinum group","url":"https://en.wikipedia.org/wiki/Platinum_group"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"platinum-ore","name":"Platinum ore","kind":"raw","category":"ground","title":"How platinum ore is mined","url":"https://assemblyline.org/make/platinum-ore","stations":4,"upstream":0,"downstream":3,"depth":0,"dek":"Platinum is so thinly spread that at Sudbury it makes up only 0.5 parts per million of the ore.","answer":"Platinum ore lies in reefs that can be under half a meter thick. In South Africa's Bushveld Complex, crews drill low stopes along a reef, sometimes more than a kilometer underground, and scoop out the broken rock. A concentrator crushes it, mills it to powder and floats it, usually twice, before the thickened concentrate leaves for a smelter and refinery.","aka":["PGM ore","platinum group metals"],"inputs":[],"uses":["platinum","iridium"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["platinum","iridium","hard-drive"],"steps":[{"name":"Stope along the reef","process":"mine","text":"The Merensky Reef is only 46 cm thick, so crews work narrow breast stopes held up by strike pillars. Low-profile drills bore the rock, and load-haul-dump vehicles clear it. At the Amandelbult complex the workings run down to 1.3 km.","inputs":[]},{"name":"Crush and reject waste","process":"crush","text":"One Bushveld plant crushes Merensky contact reef to under 16 mm and sends it through a dense-media separator that throws out waste before crushing it again. Chrome-rich UG2 ore gets coarse crushing and goes straight to the mills.","inputs":[]},{"name":"Mill and float twice","process":"separate","text":"Ore is milled until about 40% of it is finer than 75 microns, then floated. Tailings from that float go to a second mill, reaching 80% below 75 microns, and float again to catch what the first pass missed.","inputs":[]},{"name":"Thicken and dispatch","process":"dry","text":"Concentrate is thickened and filtered, then shipped to smelting, converting and refining plants. Tailings are pumped to a dam, though they can be rich enough in chromite to reprocess.","inputs":[]}],"facts":["Most known platinum lies in the Merensky and UG2 reefs of South Africa's Bushveld Complex.","Hans Merensky, a geologist, traced a huge store of platinum in South Africa's Bushveld Igneous Complex after a discovery there in 1924.","In the Sudbury Basin platinum makes up only 0.5 ppm of the ore, and it is recovered because huge amounts of nickel ore are processed anyway."],"where":[],"whereNote":null,"sources":[{"title":"Tumela Mine, Thabazimbi","url":"https://www.mining-technology.com/projects/tumela-mine-thabazimbi/"},{"title":"Spiral separation for optimised recovery","url":"https://www.crown.co.za/latest-news/mechchem-africa-latest-news/28505-spiral-separation-for-optimised-recovery"},{"title":"Pilanesburg Platinum Project (DRA)","url":"https://draglobal.com/projects/pilanesburg-platinum-project"},{"title":"Merensky Reef","url":"https://en.wikipedia.org/wiki/Merensky_Reef"},{"title":"Platinum","url":"https://en.wikipedia.org/wiki/Platinum"},{"title":"Platinum group","url":"https://en.wikipedia.org/wiki/Platinum_group"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"playing-cards","name":"Playing cards","kind":"product","category":"wood-paper","title":"How playing cards are made","url":"https://assemblyline.org/make/playing-cards","stations":6,"upstream":56,"downstream":0,"depth":9,"dek":"Playing cards have a black glue layer hidden in the middle so you cannot see through them.","answer":"Playing cards are cut from pasteboard, a sandwich of paper sheets glued together with dark glue so light cannot pass through. Art is printed on each side of a big sheet, a coating gives it a smooth or textured finish, and machines cut the sheet into cards, round the corners, sort them into decks and wrap them in tuck boxes.","aka":["deck of cards","cards","pasteboard"],"inputs":["paper","adhesive","ink","cardboard"],"uses":[],"grounds":["water","kaolin","limestone","timber","crude-oil","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","natural-gas","coal","sugar-beet"],"upstreamSlugs":["paper","adhesive","ink","cardboard","wood-pulp","water","kaolin","limestone","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","hydrogen","soybeans","rapeseed","hexane","clay","formaldehyde","air","titanium-ore","coke","iron-ore","sulfur","corn","sugarcane","yeast","rock-salt","naphtha","natural-gas","benzene","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Glue sheets into pasteboard","process":"laminate","text":"Large sheets of paper are glued together into one stiff board. The glue is black or another dark color, so the finished cards are opaque and no one can read them from the back.","inputs":["paper","adhesive"]},{"name":"Print both faces","process":"print","text":"Plates carry the artwork, and each side of the pasteboard is printed. Registration must be exact, because a card whose back is off-center can give away its value.","inputs":["ink"]},{"name":"Varnish the surface","process":"coat","text":"A water-based or solvent-based coating is applied over the ink to protect it. Dyes, foils or extra coating passes can give the finish a smooth or textured feel.","inputs":[]},{"name":"Cut out single cards","process":"cut","text":"The pasteboard is split into uncut sheets, and these are cut into individual cards. The corners are then rounded, because sharp corners wear out quickly.","inputs":[]},{"name":"Sort into decks","process":"assemble","text":"Machines gather the right cards into complete decks. A standard French-suited deck has 52 cards.","inputs":[],"spec":"52 cards"},{"name":"Wrap in tuck boxes","process":"package","text":"Each deck goes into a tuck box, often wrapped in cellophane, and the box may be sealed.","inputs":["cardboard"]}],"facts":["Playing cards were most likely invented during the Tang dynasty around the 9th century, soon after woodblock printing.","The Japanese company Nintendo was founded in 1889 to make and sell hanafuda flower cards.","The joker is an American invention, devised for the game euchre."],"where":[],"whereNote":null,"sources":[{"title":"Playing card","url":"https://en.wikipedia.org/wiki/Playing_card"},{"title":"Paperboard","url":"https://en.wikipedia.org/wiki/Paperboard"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"plywood","name":"Plywood","kind":"material","category":"wood-paper","title":"How plywood is made","url":"https://assemblyline.org/make/plywood","stations":6,"upstream":28,"downstream":6,"depth":8,"dek":"Plywood starts as a log peeled like a roll of paper towels, then stacked with every layer's grain crosswise.","answer":"Plywood is made by spinning a log against a long blade, which peels it into thin sheets of wood veneer. The sheets are dried, graded, coated with glue and stacked so the grain of each layer runs at right angles to its neighbors. A hot press bakes the stack into a flat, strong panel that is trimmed and sanded.","aka":["ply","veneer board","marine ply"],"inputs":["timber","adhesive"],"uses":["shipping-container","drum-kit","door","ceiling-fan","pinball-machine","loudspeaker"],"grounds":["timber","water","crude-oil","natural-gas","air","sulfur","rock-salt","coal"],"upstreamSlugs":["timber","adhesive","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","naphtha","natural-gas","air","sulfur","benzene","rock-salt","toluene","coal"],"downstreamSlugs":["shipping-container","drum-kit","door","ceiling-fan","pinball-machine","loudspeaker"],"steps":[{"name":"Peel the log","process":"machine","text":"A straight, wide log is laid horizontally and spun on its long axis while a blade presses into it. A continuous sheet of wood unrolls, the way paper comes off a roll. A bar presses on the log beside the blade to hold the sheet to an exact thickness.","inputs":["timber"]},{"name":"Clip and dry the sheets","process":"dry","text":"The long ribbon of veneer is cut into sheets slightly bigger than the finished panel, because wood shrinks as it dries. Dryers then take out the water so the glue will bond properly.","inputs":[]},{"name":"Patch and sort the veneer","process":"inspect","text":"Workers grade the sheets and patch knot holes and splits. The best sheets are saved for the outer faces, and plainer ones go inside.","inputs":[]},{"name":"Glue and cross-stack","process":"laminate","text":"Glue is spread on each sheet and the layers are stacked with the grain turned 90 degrees from layer to layer. That alternation keeps nails from splitting the edges and stops the panel from swelling and shrinking much across its width. The number of layers is always odd. Indoor panels use a cheaper glue with limited water resistance, and outdoor and marine panels use a waterproof one.","inputs":["adhesive"]},{"name":"Bake in a hot press","process":"press","text":"The stack goes into a heated press that squeezes the layers together while the glue cures. The panel comes out as a single flat board.","inputs":[],"spec":"at least 140 °C"},{"name":"Trim and sand","process":"grind","text":"The panel is cut to its standard size, small surface flaws are filled, and sanders smooth both faces for the market it is headed to.","inputs":[]}],"facts":["The British De Havilland Mosquito aircraft used plywood for its wing surfaces and was nicknamed the Wooden Wonder.","The standard 4 by 8 foot sheet traces to a veneer-core plywood developed for the 1905 Portland World Fair.","Howard Hughes's H-4 Hercules airplane was built of plywood and resin."],"where":[],"whereNote":null,"sources":[{"title":"Plywood","url":"https://en.wikipedia.org/wiki/Plywood"},{"title":"Lumber","url":"https://en.wikipedia.org/wiki/Lumber"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"polycarbonate","name":"Polycarbonate","kind":"material","category":"plastics","title":"How polycarbonate is made","url":"https://assemblyline.org/make/polycarbonate","stations":5,"upstream":17,"downstream":15,"depth":6,"dek":"Polycarbonate is a clear plastic built from a molecule called bisphenol A, joined by a carbonate link.","answer":"Polycarbonate is made by joining bisphenol A, a molecule made of phenol and acetone, to carbonate groups. In the main factory route, the bisphenol is first dissolved in caustic soda, then reacted with a chlorine-based reagent in a solvent. The polymer is washed, dried and extruded into clear pellets.","aka":["PC","Lexan","Makrolon"],"inputs":["phenol","propylene","acetone","caustic-soda","chlorine"],"uses":["led-bulb","drone","eyeglass-lens","sunglasses","bike-helmet","blender","suitcase","smartwatch","wireless-earbuds","phone-charger","digital-camera","camera-lens","compact-disc","game-console"],"grounds":["air","crude-oil","rock-salt","water","sulfur","natural-gas","coal"],"upstreamSlugs":["phenol","propylene","acetone","caustic-soda","chlorine","benzene","air","naphtha","crude-oil","rock-salt","water","sulfuric-acid","hydrogen","toluene","sulfur","natural-gas","coal"],"downstreamSlugs":["led-bulb","drone","eyeglass-lens","sunglasses","bike-helmet","blender","suitcase","smartwatch","wireless-earbuds","phone-charger","digital-camera","camera-lens","compact-disc","game-console","eyeglass-frame"],"steps":[{"name":"Make bisphenol A","process":"react","text":"Phenol and acetone, both made from propylene and benzene, are condensed into bisphenol A. Crystals are purified until they are very clean.","inputs":["phenol","propylene","acetone"]},{"name":"Dissolve it in lye","process":"mix","text":"The bisphenol A is treated with sodium hydroxide, which prepares its hydroxyl groups to link up. This turns the crystals into a water-soluble salt.","inputs":["caustic-soda"]},{"name":"Join it with the carbonate unit","process":"react","text":"The salt reacts with a chlorine-based carbonyl reagent made from chlorine. A closed, tightly controlled reactor grows the chains where water and solvent meet.","inputs":["chlorine"]},{"name":"Wash out the salts","process":"wash","text":"The polymer solution is washed free of salt and leftover reagents. The solvent is then evaporated and recycled.","inputs":[]},{"name":"Extrude and pellet it","process":"extrude","text":"An extruder melts the polymer, filters it, and cuts it into clear pellets. Molders turn the pellets into lenses, sheet, headlight covers and discs.","inputs":[]}],"facts":["About 10 million tonnes of bisphenol A were produced worldwide in 2022.","Making polycarbonate is the largest single use of bisphenol A, accounting for 65 to 70% of all of it.","Polycarbonate is used instead of glass in some displays, though other screens still need glass for its higher melting temperature."],"where":[],"whereNote":null,"sources":[{"title":"Polycarbonate","url":"https://en.wikipedia.org/wiki/Polycarbonate"},{"title":"Bisphenol A","url":"https://en.wikipedia.org/wiki/Bisphenol_A"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"polyester","name":"Polyester","kind":"material","category":"plastics","title":"How polyester fiber is made","url":"https://assemblyline.org/make/polyester","stations":6,"upstream":18,"downstream":69,"depth":6,"dek":"Polyester fiber is the same plastic as a soda bottle, melted and pushed through a plate full of tiny holes.","answer":"Polyester fiber is made from PET. Dried PET chips are melted and pumped through a plate full of tiny holes, called a spinneret. The strands cool in air, are stretched to align their molecules, and are either wound as continuous filament or crimped and cut into short lengths for spinning like cotton.","aka":["polyester fiber","PET fiber","Dacron"],"inputs":["pet-plastic"],"uses":["tire","soccer-ball","marker-pen","highlighter","sofa","office-chair","pillow","garden-hose","volleyball","kite","kitchen-sponge","wet-wipes","seat-belt","canoe","sailboat","hoodie","leggings","swimsuit","raincoat","backpack","suitcase","shoelace","curtain","flag","wireless-earbuds","microphone","sneaker","mattress","umbrella","zipper","button","thread","teddy-bear"],"grounds":["natural-gas","water","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","water","oxygen","carbon-dioxide","crude-oil","hydrogen","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["tire","soccer-ball","marker-pen","highlighter","sofa","office-chair","pillow","garden-hose","volleyball","kite","kitchen-sponge","wet-wipes","seat-belt","canoe","sailboat","hoodie","leggings","swimsuit","raincoat","backpack","suitcase","shoelace","curtain","flag","wireless-earbuds","microphone","sneaker","mattress","umbrella","zipper","button","thread","teddy-bear","car","electric-car","bicycle","motorcycle","down-jacket","handbag","jeans","dress-shirt","suit","baseball-cap","airbag","baseball","fireworks","bike-helmet","candle","ice-skates","fishing-rod","football","yo-yo","fashion-doll","tampon","silk-tie","underwear","winter-gloves","leather-belt","wallet","hiking-boots","high-heels","felt-hat","blanket","book","t-shirt","socks","sweater","leather-shoe","towel"],"steps":[{"name":"Dry the PET chips","process":"dry","text":"Chips of PET are dried in a hot airstream, because even a trace of water would break the chains when the plastic melts. Dry chips are fed straight to the spinning machine.","inputs":["pet-plastic"]},{"name":"Melt them in an extruder","process":"melt","text":"A screw pushes the chips through a heated barrel where they melt into a clear, thick liquid. A pump meters the melt precisely into each spinning position.","inputs":[]},{"name":"Press it through the spinneret","process":"spin","text":"The molten polymer is forced through a metal plate drilled with many fine holes. Each hole makes one filament, and cool air blown across them freezes the strands.","inputs":[]},{"name":"Stretch the filaments","process":"draw","text":"The strands are drawn to several times their spun length, which lines up the molecules and makes the fiber strong and less stretchy.","inputs":[]},{"name":"Crimp, cut or wind","process":"cut","text":"Continuous filament is wound onto bobbins for weaving. For staple fiber, the tow is crimped into waves and cut into short lengths that can be spun like cotton or wool.","inputs":[]},{"name":"Spin it into yarn","process":"spin","text":"Staple fibers are blended, often with cotton, and twisted into yarn. It resists water, wind and weather better than plant-derived fibers do.","inputs":[]}],"facts":["Polyester is increasingly made from recycled PET, especially post-consumer plastic bottles.","Sold as Dacron, it also makes sailboat sails, and it is blended with natural fibers to give cloth that combines the properties of both."],"where":[],"whereNote":null,"sources":[{"title":"Polyester","url":"https://en.wikipedia.org/wiki/Polyester"},{"title":"Polyethylene terephthalate","url":"https://en.wikipedia.org/wiki/Polyethylene_terephthalate"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"polyethylene","name":"Polyethylene","kind":"material","category":"plastics","title":"How polyethylene is made","url":"https://assemblyline.org/make/polyethylene","stations":6,"upstream":6,"downstream":188,"depth":4,"dek":"The most-made plastic was found by accident in 1933, when ICI chemists squeezed ethylene hard and got white wax.","answer":"Polyethylene is made by linking ethylene molecules into very long chains, using a catalyst or a high-pressure reactor. The result is a powder or molten plastic. It is melted, mixed with additives, pushed through a die and chopped into small pellets, which other factories turn into bags, bottles, pipe and film.","aka":["polythene","PE","HDPE","LDPE"],"inputs":["ethylene"],"uses":["toothpaste","hip-implant","adhesive","plastic-bag","duct-tape","lithium-ion-cell","glass-bottle","frozen-peas","bubble-wrap","plastic-wrap","zip-bag","paper-cup","thermos","ski","snowboard","frisbee","sanitary-pad","power-cable","car-battery","backpack","flip-flops","usb-cable","diaper"],"grounds":["natural-gas","water","crude-oil"],"upstreamSlugs":["ethylene","naphtha","natural-gas","water","crude-oil","hydrogen"],"downstreamSlugs":["toothpaste","hip-implant","adhesive","plastic-bag","duct-tape","lithium-ion-cell","glass-bottle","frozen-peas","bubble-wrap","plastic-wrap","zip-bag","paper-cup","thermos","ski","snowboard","frisbee","sanitary-pad","power-cable","car-battery","backpack","flip-flops","usb-cable","diaper","adhesive-bandage","credit-card","led-bulb","ev-battery","pencil","nail","insulation","popcorn","windshield","skateboard","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","pencil-eraser","clear-tape","staple","sofa","ice-skates","golf-club","fishing-rod","volleyball","cricket-bat","dartboard","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","globe","snow-globe","pinball-machine","kitchen-sponge","cotton-swab","roof-shingle","double-glazed-window","brake-pad","sailboat","dress-shirt","suit","raincoat","handbag","suitcase","wallet","hiking-boots","high-heels","smartwatch","wireless-earbuds","loudspeaker","microphone","camera-lens","e-reader","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","sneaker","leather-shoe","baseball-cap","carpet","mattress","syringe","vacuum-cleaner","electric-kettle","cotton-candy","pillow","smartphone","laptop","drone","satellite","digital-camera","electric-toothbrush","nail-polish","perfume","penicillin","insulin","vaccine","ketchup","cola","sparkling-water","beer","wine","champagne","whiskey","vodka","gin","rum","tequila","sake","hard-cider","hot-sauce","soda","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","port-wine","prosecco","non-alcoholic-beer","aa-battery","candy-cane","electric-car","dishwasher","car","aluminum-window-frame","shipping-container","ceiling-fan","treadmill","toothbrush","fireworks","trading-cards","cake-mix","energy-drink","hair-dye","tampon","soap","deodorant","detergent","nitrile-glove","washing-machine","paperclip","donut","corn-flakes","rubiks-cube","crayon","candle","salsa","canned-meat","fish-sticks","blender","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","game-console","wifi-router","remote-control","facial-tissue","shampoo","air-freshener","dish-soap","hairspray","foundation-makeup"],"steps":[{"name":"Purify the ethylene","process":"refine","text":"Ethylene gas is cleaned of moisture and traces of other compounds. Impurities would kill the catalyst and cut the chain length of the polymer.","inputs":["ethylene"]},{"name":"Link the molecules in a reactor","process":"react","text":"Inside a reactor, thousands of ethylene molecules join into long chains. A Ziegler-Natta, chromium or metallocene catalyst, or a high-pressure free-radical process, sets the chain structure and so the type of plastic.","inputs":[]},{"name":"Separate the polymer","process":"separate","text":"Unreacted gas and solvent are flashed off and recycled. What is left is a powder or a molten polymer.","inputs":[]},{"name":"Melt and mix in additives","process":"mix","text":"An extruder melts the polymer and blends in antioxidants, color and other additives. The mix is pushed through a die plate with many small holes.","inputs":[]},{"name":"Chop it into pellets","process":"cut","text":"Rotating blades slice the strands at the die into small pellets under water. The pellets are dried and sorted by size.","inputs":[]},{"name":"Bag and ship the resin","process":"package","text":"Pellets are blown into silos, bags or rail hopper cars. Film plants, bottle makers and pipe extruders buy them by the truckload.","inputs":[]}],"facts":["Polyethylene is the most commonly produced plastic, with over 100 million tonnes of resin made each year as of 2017.","Its low loss to radio waves led Britain to suppress commercial sales at the start of World War II and use it to insulate the cables of radar sets.","Its chemical resilience makes it long-lasting but also a decomposition-resistant pollutant when it is thrown away carelessly."],"where":[],"whereNote":null,"sources":[{"title":"Polyethylene","url":"https://en.wikipedia.org/wiki/Polyethylene"},{"title":"Ziegler-Natta catalyst","url":"https://en.wikipedia.org/wiki/Ziegler%E2%80%93Natta_catalyst"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"polypropylene","name":"Polypropylene","kind":"material","category":"plastics","title":"How polypropylene is made","url":"https://assemblyline.org/make/polypropylene","stations":5,"upstream":6,"downstream":25,"depth":4,"dek":"Giulio Natta found in 1954 that the right catalyst makes propylene line up its molecules like teeth on a zipper.","answer":"Polypropylene is made by linking propylene gas molecules into long chains in a reactor, using a catalyst that lines every unit up the same way. The powder that results is melted, mixed with stabilizers, pushed through a die and chopped into pellets. Other factories mold, spin or extrude the pellets into finished parts.","aka":["PP","polypropene"],"inputs":["propylene"],"uses":["toothbrush","deodorant","mascara","syringe","electric-kettle","plastic-straw","clear-tape","dishwasher","office-chair","frisbee","sanitary-pad","cotton-swab","wet-wipes","dental-floss","prosthetic-leg","car-battery","suitcase","loudspeaker","baseball-cap","carpet","rope","diaper","n95-mask"],"grounds":["crude-oil","water","natural-gas"],"upstreamSlugs":["propylene","naphtha","crude-oil","water","hydrogen","natural-gas"],"downstreamSlugs":["toothbrush","deodorant","mascara","syringe","electric-kettle","plastic-straw","clear-tape","dishwasher","office-chair","frisbee","sanitary-pad","cotton-swab","wet-wipes","dental-floss","prosthetic-leg","car-battery","suitcase","loudspeaker","baseball-cap","carpet","rope","diaper","n95-mask","car","kite"],"steps":[{"name":"Purify the propylene","process":"refine","text":"Propylene is cleaned of water, sulfur and other poisons that would foul the catalyst. The feed has to be clean for the chains to grow long.","inputs":["propylene"]},{"name":"Grow chains on a catalyst","process":"react","text":"In the reactor, propylene meets a Ziegler-Natta catalyst. The catalyst makes each new unit attach in the same orientation, which gives isotactic chains that pack tightly and make a stiff, partly crystalline plastic.","inputs":[]},{"name":"Strip off leftover gas","process":"separate","text":"Unreacted propylene is flashed off and sent back to the reactor. The powder left behind is dried.","inputs":[]},{"name":"Melt in stabilizers","process":"mix","text":"An extruder melts the powder and mixes in heat stabilizers and other additives. Without stabilizers the plastic would degrade in sunlight and heat.","inputs":[]},{"name":"Cut it into pellets","process":"cut","text":"The molten strands are chopped into pellets as they leave the die. Pellets are cooled, dried and bagged for sale.","inputs":[]}],"facts":["Polypropylene is the second most widely produced commodity plastic, after polyethylene.","Giulio Natta and Karl Rehn discovered the stereoselective polymerization of propylene in March 1954, and Montecatini began large-scale production in 1957."],"where":[],"whereNote":null,"sources":[{"title":"Polypropylene","url":"https://en.wikipedia.org/wiki/Polypropylene"},{"title":"Ziegler-Natta catalyst","url":"https://en.wikipedia.org/wiki/Ziegler%E2%80%93Natta_catalyst"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"polysilicon","name":"Polysilicon","kind":"material","category":"electronics","title":"How polysilicon is made","url":"https://assemblyline.org/make/polysilicon","stations":5,"upstream":17,"downstream":34,"depth":5,"dek":"Electronics-grade polysilicon carries fewer than one impurity atom in a billion, grown onto glowing rods.","answer":"Polysilicon starts as metallurgical silicon that is turned into liquid trichlorosilane, distilled clean, then decomposed with hydrogen onto thin silicon rods heated to 1,150 °C. The rods thicken for about two days until they reach 120 mm across. They are then broken into chunks and sealed in bags filled with nitrogen or argon.","aka":["polycrystalline silicon","poly-Si","Siemens process silicon","electronic-grade silicon"],"inputs":["silicon","hydrochloric-acid","trichlorosilane","hydrogen","nitrogen"],"uses":["silicon-wafer"],"grounds":["quartz","coal","timber","water","natural-gas","air","rock-salt","sulfur"],"upstreamSlugs":["silicon","hydrochloric-acid","trichlorosilane","hydrogen","nitrogen","quartz","coke","coal","charcoal","timber","chlorine","water","natural-gas","air","rock-salt","sulfuric-acid","sulfur"],"downstreamSlugs":["silicon-wafer","microchip","memory-chip","camera-sensor","solar-cell","inkjet-printer","hearing-aid","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","rocket","smartwatch","wireless-earbuds","phone-charger","usb-cable","digital-camera","game-console","wifi-router","e-reader","graphics-card","remote-control","electric-toothbrush","solar-panel","car"],"steps":[{"name":"Turn silicon into a gas","process":"react","text":"Metallurgical silicon of about 98% purity is reacted with hydrogen chloride gas to make trichlorosilane, a volatile liquid that boils easily, with hydrogen released as a by-product. Because silicon is now part of a molecule, metals and dopants can be separated out.","inputs":["silicon","hydrochloric-acid"]},{"name":"Distill it clean","process":"refine","text":"The trichlorosilane is distilled repeatedly, and transition metals and dopant impurities stay behind. Electronics grade ends up with impurity levels below one part per billion.","inputs":[],"spec":"under 1 part per billion"},{"name":"Grow silicon on hot rods","process":"deposit","text":"Thin silicon rods stand inside a water-cooled reactor, and an electric current heats them to 1,150 °C. Trichlorosilane and hydrogen flow over them, and silicon settles on the hot surface until the rods reach 120 mm in diameter after about 46 hours.","inputs":["trichlorosilane","hydrogen"],"spec":"1,150 °C for 46 hours"},{"name":"Harvest and break rods","process":"crush","text":"Each batch is opened and the rods are pulled out and broken into chunks. The whole cycle takes about 60 hours, and plants keep backup power because an interrupted run is ruined.","inputs":[]},{"name":"Bag it under inert gas","process":"package","text":"Chunks are packed in clean rooms inside bags filled with nitrogen or argon, so nothing settles on the surface in transit.","inputs":["nitrogen"]}],"facts":["Rods from the process run two to three meters long before they are broken up.","Plants keep backup power for the reactors, because a batch runs about 60 hours and an interrupted one is ruined.","The Siemens company invented the process in 1954, and it still accounted for close to 75% of polysilicon output in 2005."],"where":[],"whereNote":null,"sources":[{"title":"Polysilicon","url":"https://en.wikipedia.org/wiki/Polysilicon"},{"title":"Silicon","url":"https://en.wikipedia.org/wiki/Silicon"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"polystyrene","name":"Polystyrene","kind":"material","category":"plastics","title":"How polystyrene is made","url":"https://assemblyline.org/make/polystyrene","stations":6,"upstream":10,"downstream":8,"depth":6,"dek":"Foam cups and clear CD cases come from the same molecule, styrene, which is built from ethylene and benzene.","answer":"Polystyrene is made from styrene, which is built from benzene and ethylene. Styrene is linked into long chains in a reactor, then the leftover monomer is stripped out and the melt is cut into pellets. Foam versions are made by soaking beads in a gas and expanding them with steam.","aka":["PS","Styrofoam","expanded polystyrene","EPS"],"inputs":["naphtha","ethylene","benzene","styrene"],"uses":["surfboard","bike-helmet","ballpoint-pen","polystyrene-foam","foam-cup","smoke-detector","compact-disc","inkjet-printer"],"grounds":["crude-oil","water","natural-gas","coal"],"upstreamSlugs":["naphtha","ethylene","benzene","styrene","crude-oil","water","hydrogen","natural-gas","toluene","coal"],"downstreamSlugs":["surfboard","bike-helmet","ballpoint-pen","polystyrene-foam","foam-cup","smoke-detector","compact-disc","inkjet-printer"],"steps":[{"name":"Extract benzene from naphtha","process":"refine","text":"A refinery reforms naphtha to make aromatic compounds, and benzene is distilled out. It is the ring-shaped heart of styrene.","inputs":["naphtha"]},{"name":"Attach ethylene to the ring","process":"react","text":"Benzene and ethylene react over a catalyst to give ethylbenzene. Almost all ethylbenzene made in the world goes on to become styrene.","inputs":["ethylene","benzene"]},{"name":"Strip off hydrogen","process":"react","text":"Ethylbenzene is heated with steam over a catalyst, which pulls off two hydrogen atoms. The product is styrene, a liquid that is distilled clean.","inputs":[]},{"name":"Link styrene into chains","process":"react","text":"Styrene is heated in a reactor and polymerizes into polystyrene, thickening as the chains grow.","inputs":["styrene"]},{"name":"Remove leftover monomer","process":"refine","text":"A vacuum chamber pulls unreacted styrene out of the thick melt, and it is recycled to the reactor. The polymer is then ready to shape.","inputs":[]},{"name":"Pellet it or foam it","process":"mold","text":"Clear general-purpose polystyrene is extruded and cut into pellets. Foam beads are soaked with a blowing agent and puffed with steam, which fuses them into a block that is full of trapped air.","inputs":[]}],"facts":["Polystyrene turns glassy at room temperature and flows when heated above its glass transition temperature of about 100 °C.","Roughly 35 million tonnes of styrene were produced worldwide by 2018."],"where":[],"whereNote":null,"sources":[{"title":"Polystyrene","url":"https://en.wikipedia.org/wiki/Polystyrene"},{"title":"Styrene","url":"https://en.wikipedia.org/wiki/Styrene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"polyurethane","name":"Polyurethane","kind":"material","category":"plastics","title":"How polyurethane is made","url":"https://assemblyline.org/make/polyurethane","stations":6,"upstream":13,"downstream":153,"depth":4,"dek":"Polyurethane foam in a couch is a chemical reaction that happens in seconds and puffs up like bread dough.","answer":"Polyurethane is made by reacting two liquids, a polyol and an isocyanate. Metering pumps send them to a mixing head with catalysts and a little water or gas. The mixture foams and rises as it cures. On a long conveyor it forms a continuous block, which is cut into cushion shapes.","aka":["PU","PUR","polyurethane foam","spandex"],"inputs":["propylene","nitric-acid","chlorine","water"],"uses":["adhesive-bandage","pacemaker","adhesive","refrigerator","car","skateboard","surfboard","golf-ball","soccer-ball","bike-helmet","hardwood-floor","water-heater","sofa","office-chair","roller-skates","tennis-racket","volleyball","bowling-ball","wheelchair","underwear","leggings","swimsuit","raincoat","backpack","sneaker","mattress"],"grounds":["water","crude-oil","air","rock-salt","natural-gas","sulfur"],"upstreamSlugs":["propylene","nitric-acid","chlorine","water","naphtha","crude-oil","ammonia","air","rock-salt","sulfuric-acid","hydrogen","natural-gas","sulfur"],"downstreamSlugs":["adhesive-bandage","pacemaker","adhesive","refrigerator","car","skateboard","surfboard","golf-ball","soccer-ball","bike-helmet","hardwood-floor","water-heater","sofa","office-chair","roller-skates","tennis-racket","volleyball","bowling-ball","wheelchair","underwear","leggings","swimsuit","raincoat","backpack","sneaker","mattress","credit-card","duct-tape","led-bulb","ev-battery","pencil","nail","insulation","popcorn","windshield","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","pencil-eraser","clear-tape","staple","ski","snowboard","ice-skates","golf-club","fishing-rod","cricket-bat","dartboard","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","globe","snow-globe","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","brake-pad","sailboat","dress-shirt","suit","handbag","suitcase","wallet","flip-flops","hiking-boots","high-heels","smartwatch","wireless-earbuds","loudspeaker","microphone","camera-lens","e-reader","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","leather-shoe","baseball-cap","carpet","diaper","electric-car","dishwasher","aluminum-window-frame","digital-camera","shipping-container","ceiling-fan","treadmill","toothbrush","fireworks","plastic-wrap","trading-cards","cake-mix","soda","energy-drink","hair-dye","tampon","soap","toothpaste","deodorant","detergent","plastic-bag","nitrile-glove","washing-machine","vacuum-cleaner","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","blender","pillow","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","game-console","wifi-router","remote-control","facial-tissue","aa-battery","candy-cane","syringe"],"steps":[{"name":"Make the polyol","process":"react","text":"Propylene is converted to propylene oxide, which is built up into long, flexible chains with a hydroxyl group at each end. These are the polyols.","inputs":["propylene"]},{"name":"Make the isocyanate","process":"react","text":"Nitric acid and a chlorine-based reagent are used to convert aromatic petrochemicals into isocyanates in closed plants with strict safety controls. These are the reactive partners of the polyol.","inputs":["nitric-acid","chlorine"]},{"name":"Meter and mix the streams","process":"mix","text":"High-pressure pumps measure the polyol, the isocyanate, a catalyst, a surfactant and a small amount of water into a mixing head. Proportions decide whether the foam is soft or rigid.","inputs":["water"]},{"name":"Pour and let it rise","process":"cast","text":"Poured onto a moving conveyor, the mix begins to react at once. Water makes carbon dioxide bubbles that inflate the foam as the polymer sets around them.","inputs":[]},{"name":"Cure the foam block","process":"dry","text":"The block, sometimes several meters across, is left to finish reacting and cool. Heat from the reaction runs through it for hours.","inputs":[]},{"name":"Slice and shape it","process":"cut","text":"Blades slice the block into sheets for mattresses and cushions. Rigid foam for insulation panels is made by similar reactions.","inputs":[]}],"facts":["Foams are the largest use of polyurethane, accounting for 67% of all of it in 2016.","Otto Bayer and his team at IG Farben in Leverkusen first made polyurethanes in 1937.","Global polyurethane production in 2019 was 25 million metric tonnes, about 6% of all polymers."],"where":[],"whereNote":null,"sources":[{"title":"Polyurethane","url":"https://en.wikipedia.org/wiki/Polyurethane"},{"title":"Polymerization","url":"https://en.wikipedia.org/wiki/Polymerization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"polyvinyl-alcohol","name":"Polyvinyl alcohol","kind":"material","category":"plastics","title":"How polyvinyl alcohol is made","url":"https://assemblyline.org/make/polyvinyl-alcohol","stations":5,"upstream":11,"downstream":5,"depth":4,"dek":"Its building block does not exist in a usable form. So chemists make a different plastic and rewrite it afterward.","answer":"Vinyl alcohol, the obvious starting molecule, is unstable and rearranges into acetaldehyde. Plants instead make vinyl acetate from ethylene, link it into polyvinyl acetate, dissolve that in alcohol, and use a catalyst to swap the acetate groups for hydroxyl groups. The chain survives intact, and the finished plastic dissolves in water, which is why it wraps laundry pods.","aka":["PVA","PVOH","PVAl"],"inputs":["ethylene","oxygen","methanol","caustic-soda"],"uses":["pvb","banknote"],"grounds":["natural-gas","water","air","rock-salt","crude-oil"],"upstreamSlugs":["ethylene","oxygen","methanol","caustic-soda","naphtha","natural-gas","water","air","rock-salt","crude-oil","hydrogen"],"downstreamSlugs":["pvb","banknote","windshield","car","electric-car"],"steps":[{"name":"Make vinyl acetate","process":"react","text":"Ethylene, acetic acid and oxygen react over a palladium catalyst. This route has replaced the older one based on acetylene. About 80% of this monomer goes on to make the polymer in this line.","inputs":["ethylene","oxygen"]},{"name":"Link up the monomer","process":"react","text":"A free-radical reaction joins the molecules into polyvinyl acetate, the same polymer found in white wood glue. It has long been valued as an adhesive in its own right.","inputs":[]},{"name":"Dissolve in alcohol","process":"mix","text":"The polymer is dissolved in an alcohol such as methanol or ethanol, ready for the swap. An alkaline catalyst such as sodium hydroxide is added.","inputs":["methanol","caustic-soda"]},{"name":"Swap off the acetate","process":"react","text":"The catalyst removes the acetate groups and leaves the long chain undisturbed. Running this to completion gives a product that dissolves freely in water. Stopping early gives grades less soluble in water and more soluble in some organic liquids.","inputs":[]},{"name":"Dry into beads","process":"dry","text":"The finished polymer is supplied as white, odorless beads or as a solution in water. Buyers use it for textile sizing, paper coatings, adhesives and water-soluble films.","inputs":[]}],"facts":["Laundry detergent pods use polyvinyl alcohol because its film dissolves in the wash.","Water absorbed in humid air acts as a plasticizer in polyvinyl alcohol, weakening it but letting it stretch further.","World consumption was over one million metric tons in 2006."],"where":[],"whereNote":null,"sources":[{"title":"Polyvinyl alcohol","url":"https://en.wikipedia.org/wiki/Polyvinyl_alcohol"},{"title":"Polyvinyl acetate","url":"https://en.wikipedia.org/wiki/Polyvinyl_acetate"},{"title":"Vinyl acetate","url":"https://en.wikipedia.org/wiki/Vinyl_acetate"},{"title":"Polyvinyl alcohol (Britannica)","url":"https://www.britannica.com/science/polyvinyl-alcohol"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pvb","name":"Polyvinyl butyral","kind":"material","category":"plastics","title":"How polyvinyl butyral interlayer is made","url":"https://assemblyline.org/make/pvb","stations":6,"upstream":14,"downstream":3,"depth":5,"dek":"The clear film that holds a cracked windshield together is a resin built from polyvinyl alcohol.","answer":"Polyvinyl butyral begins when polyvinyl alcohol reacts with butyraldehyde under an acid catalyst. The resin is neutralized, separated, stabilized and dried, then mixed with plasticizer, because alone it is too stiff to soak up a blow. Melted and forced through a long slot die, it becomes a sheet 0.13 to 1.3 mm thick, ready to go between two panes of glass.","aka":["PVB","windshield interlayer","laminated glass film"],"inputs":["polyvinyl-alcohol","propylene","plasticizer"],"uses":["windshield"],"grounds":["crude-oil","air","natural-gas","water","rock-salt"],"upstreamSlugs":["polyvinyl-alcohol","propylene","plasticizer","ethylene","oxygen","methanol","caustic-soda","naphtha","crude-oil","air","natural-gas","water","rock-salt","hydrogen"],"downstreamSlugs":["windshield","car","electric-car"],"steps":[{"name":"React alcohol with aldehyde","process":"react","inputs":["polyvinyl-alcohol","propylene"],"text":"Polyvinyl alcohol reacts with butyraldehyde, a chemical made almost entirely from propylene, in the presence of an acid catalyst. Plants can run this in water or in solvent."},{"name":"Neutralize and dry the resin","process":"dry","inputs":[],"text":"The catalyst is neutralized, and the resin is separated, stabilized and dried. It reaches customers as powder or granules. Inks, paints and ceramic binders use it in that form."},{"name":"Blend in plasticizer","process":"mix","inputs":["plasticizer"],"text":"Plain resin would be too rigid for an interlayer, so plasticizer goes in, generally 15 to 50 parts per 100 parts of resin in one patent. Ultraviolet stabilizers and adhesion control salts may join it, and pigments make the colored sheets used for a windshield's blue or green shade band."},{"name":"Extrude through a sheeting die","process":"extrude","inputs":[],"text":"Molten, plasticized resin is forced through a wide, narrow die opening shaped to the sheet being made. Some lines instead cast the melt onto a specially surfaced die roll right at the exit.","spec":"about 0.13 to 1.3 mm thick"},{"name":"Texture the sheet surface","process":"roll","inputs":[],"text":"Valleys and peaks on the die roll leave one side of the sheet rough. The design of the die opening can roughen the other side. Melt temperature and water content offer other ways to control the texture."},{"name":"Bond between glass panes","process":"laminate","inputs":[],"text":"Glassmakers lay the sheet between two panes and bond them under heat and pressure. Only then does it turn optically clear, and the sandwich behaves as a single unit."}],"facts":["When laminated glass breaks, the fragments tend to stick to the interlayer instead of falling free.","PVB is also used to encapsulate thin-film solar modules.","The same resin works as a temporary binder in technical ceramics."],"where":[],"whereNote":null,"sources":[{"title":"Polyvinyl butyral","url":"https://en.wikipedia.org/wiki/Polyvinyl_butyral"},{"title":"Butyraldehyde","url":"https://en.wikipedia.org/wiki/Butyraldehyde"},{"title":"US5013780, Plasticized polyvinyl butyral and interlayer thereof","url":"https://patents.google.com/patent/US5013780"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"polyvinylpyrrolidone","name":"Polyvinylpyrrolidone","kind":"material","category":"plastics","title":"How polyvinylpyrrolidone is made","url":"https://assemblyline.org/make/polyvinylpyrrolidone","stations":8,"upstream":8,"downstream":1,"depth":3,"dek":"The polymer that holds a hairstyle in place was first put to work as a stand-in for blood plasma.","answer":"Better known as PVP or povidone, this water-soluble polymer starts as acetylene from burned methane. A chain of plant reactions builds a five-membered ring from it, using formaldehyde, hydrogen and ammonia, and a second dose of acetylene gives that ring a vinyl group. Radical initiators then link the monomer into long chains in water, and spray drying yields a flaky powder.","aka":["PVP","povidone","E1201"],"inputs":["natural-gas","formaldehyde","hydrogen","ammonia","water","hydrogen-peroxide"],"uses":["hairspray"],"grounds":["natural-gas","water","air"],"upstreamSlugs":["natural-gas","formaldehyde","hydrogen","ammonia","water","hydrogen-peroxide","methanol","air"],"downstreamSlugs":["hairspray"],"steps":[{"name":"Burn methane to acetylene","process":"react","text":"Partial combustion of methane is the main way the US and much of the EU have made acetylene since the 1950s. This gas supplies carbon twice along the line.","inputs":["natural-gas"]},{"name":"Build the butanediol chain","process":"react","text":"In one industrial route, each acetylene molecule reacts with two of formaldehyde to give butynediol. Hydrogenation then saturates it into 1,4-butanediol, a four-carbon chain with an alcohol group at each end.","inputs":["formaldehyde","hydrogen"]},{"name":"Close the lactone ring","process":"react","text":"A dehydrogenation unit pulls hydrogen off the chain and curls it into a five-membered ring, the liquid intermediate gamma-butyrolactone. It goes straight on to the next reactor.","inputs":[]},{"name":"Swap in nitrogen","process":"react","text":"The lactone and ammonia pass as vapor through a tubular reactor packed with solid magnesium silicate. Nitrogen replaces the oxygen in the ring, giving 2-pyrrolidone. Distillation lifts it to 99.5% purity.","inputs":["ammonia"],"spec":"75 to 85% yield"},{"name":"Attach the vinyl group","process":"react","text":"Acetylene returns and reacts with the ring under a base catalyst, adding the carbon double bond that can later link up. The result is N-vinylpyrrolidone, a colorless liquid that often looks yellowish in commercial lots.","inputs":[]},{"name":"Link up the monomer","process":"react","text":"Monomer and water, sometimes with alcohol, go into a stirred reactor, and a free radical initiator such as hydrogen peroxide starts the chains. More alcohol means shorter chains, which is how the plant sets the grade, reported as a K value.","inputs":["water","hydrogen-peroxide"],"spec":"K 10 to K 100"},{"name":"Strip out leftovers","process":"refine","text":"Distillation or vacuum removes the alcohol, and water often takes its place so the product can leave the reactor as a solution. In one patented process, acid breaks down remaining monomer until only 0.1% is left.","inputs":[]},{"name":"Spray dry the solution","process":"dry","text":"The aqueous solution ships as it is or goes through a spray dryer to become a light, flaky powder. Hair care makers dissolve it again, because it dries from solution into a film.","inputs":[]}],"facts":["Dry PVP powder can pull up to 40% of its own weight in water out of the air.","Betadine, the disinfectant, is a complex of iodine and this polymer.","The wine industry uses it as a fining agent for white wine, and some brewers do the same for beer."],"where":[],"whereNote":null,"sources":[{"title":"Polyvinylpyrrolidone","url":"https://en.wikipedia.org/wiki/Polyvinylpyrrolidone"},{"title":"N-Vinylpyrrolidone","url":"https://en.wikipedia.org/wiki/N-Vinylpyrrolidone"},{"title":"2-Pyrrolidone","url":"https://en.wikipedia.org/wiki/2-Pyrrolidone"},{"title":"1,4-Butanediol","url":"https://en.wikipedia.org/wiki/1,4-Butanediol"},{"title":"Gamma-Butyrolactone","url":"https://en.wikipedia.org/wiki/Gamma-Butyrolactone"},{"title":"Acetylene","url":"https://en.wikipedia.org/wiki/Acetylene"},{"title":"US4520180A, Polymerization of vinylpyrrolidone to various molecular weights","url":"https://patents.google.com/patent/US4520180A/en"},{"title":"US5362815A, Process for making polyvinylpyrrolidone polymer having predetermined characteristics","url":"https://patents.google.com/patent/US5362815A/en"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"popping-candy","name":"Popping candy","kind":"product","category":"food","title":"How popping candy is made","url":"https://assemblyline.org/make/popping-candy","stations":6,"upstream":11,"downstream":0,"depth":4,"dek":"Pressurized gas is locked inside the sugar, and every pop is one tiny bubble reaching the air.","answer":"Popping candy is hard candy with carbon dioxide gas trapped inside. A sugar syrup is boiled down, cooled to a thick melt, and stirred under pressurized carbon dioxide. It sets while still under pressure. When the pressure is released the candy shatters, and the sealed bubbles pop as saliva dissolves the sugar around them.","aka":["Pop Rocks","crackling candy","space dust"],"inputs":["sugar","water","carbon-dioxide"],"uses":[],"grounds":["water","sugarcane","sugar-beet","natural-gas","corn","limestone"],"upstreamSlugs":["sugar","water","carbon-dioxide","sugarcane","sugar-beet","lime","natural-gas","corn","yeast","limestone","molasses"],"downstreamSlugs":[],"steps":[{"name":"Dissolve the sugars","process":"mix","text":"Sugars, including lactose from milk, are dissolved in water to make the syrup. The patent for the product describes sugar as the main ingredient, with flavoring added.","inputs":["sugar","water"]},{"name":"Boil it nearly dry","process":"cook","text":"The syrup is boiled down at about 160 degrees Celsius until only about 3 percent water is left. What remains is a thick melt.","inputs":[],"spec":"about 3% water"},{"name":"Stir in the gas","process":"mix","text":"The melt is cooled a little and intensely stirred in a pressure vessel filled with carbon dioxide. The gas is forced into the melt as many small bubbles.","inputs":["carbon-dioxide"]},{"name":"Set under pressure","process":"chill","text":"The mixture is kept under pressure while it cools and hardens, which locks the bubbles into the solid candy.","inputs":[]},{"name":"Release and shatter","process":"crush","text":"When the pressure is let off, the hard candy fractures into irregular pieces. Most of the trapped bubbles are between 225 and 350 micrometers across.","inputs":[],"spec":"225 to 350 µm bubbles"},{"name":"Sift and seal","process":"separate","text":"The pieces are screened to size and sealed in small packets right away, because humid air would dissolve the sugar and release the gas.","inputs":[]}],"facts":["A packet of popping candy holds less carbon dioxide than half a can of soda.","A rumor in the 1970s said mixing it with soda could make your stomach explode, so General Foods mailed letters to school principals to say it was false.","Two General Foods chemists patented the idea on December 12, 1961."],"where":[],"whereNote":null,"sources":[{"title":"Popping candy","url":"https://en.wikipedia.org/wiki/Popping_candy"},{"title":"US patent 4,289,794","url":"https://patents.google.com/patent/US4289794A/en"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"popsicle-stick","name":"Popsicle stick","kind":"product","category":"wood-paper","title":"How popsicle sticks are made","url":"https://assemblyline.org/make/popsicle-stick","stations":6,"upstream":1,"downstream":0,"depth":1,"dek":"Popsicle sticks start as thick birch veneer, cut slightly oversize, and are then milled thin.","answer":"Birch logs are cut into short bolts, stripped of bark, and soaked in warm water until soft. A veneer lathe peels the bolt into sheets that are a little thicker than the finished stick. The sheets are cut into cards, and a molder with fast cutter knives trims them thin and slices them into sticks, which are bundled so the ends can be rounded.","aka":["craft stick","ice pop stick","ice cream stick"],"inputs":["timber"],"uses":[],"grounds":["timber"],"upstreamSlugs":["timber"],"downstreamSlugs":[],"steps":[{"name":"Saw logs into bolts","process":"cut","text":"Logs are sawn to a standard length. Each short log is called a bolt, and its bark is removed.","inputs":["timber"]},{"name":"Soak the bolts warm","process":"cook","text":"The bolts sit in warm water long enough to soften all the way through, so the knife will peel them cleanly.","inputs":[]},{"name":"Peel a thick veneer","process":"cut","text":"A lathe turns the bolt against a heavy knife while a pressure bar pushes on the wood. This peels a smooth sheet and also compacts the wood. The sheet is cut slightly thicker than the finished stick, with roughly 20 percent to spare.","inputs":[]},{"name":"Cut the sheet into cards","process":"cut","text":"The veneer is chopped into flat cards about as long as one stick.","inputs":[]},{"name":"Mill cards into sticks","process":"machine","text":"Cards go through a molder with fast-spinning knives that shave them to final thickness and cut each card into a row of sticks in the same pass.","inputs":[]},{"name":"Bundle and round the ends","process":"grind","text":"Sticks are packed in tight bundles so a rounding tool can shape the ends of a whole bundle at once.","inputs":[]}],"facts":["Frank Epperson of Oakland patented frozen ice on a stick in 1923, after a story that he left lemonade soda and a mixing stick out overnight as an 11-year-old.","Birch is often used for popsicle sticks because it is durable, smooth, and has a neutral flavor.","Old methods chopped sticks out of softened veneer and left ragged edges that could shed slivers."],"where":[],"whereNote":null,"sources":[{"title":"Production of sticks (US patent 2615484)","url":"https://patents.google.com/patent/US2615484"},{"title":"Birch","url":"https://en.wikipedia.org/wiki/Birch"},{"title":"Ice pop","url":"https://en.wikipedia.org/wiki/Ice_pop"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"porcelain","name":"Porcelain","kind":"material","category":"minerals","title":"How porcelain is made","url":"https://assemblyline.org/make/porcelain","stations":6,"upstream":18,"downstream":1,"depth":5,"dek":"Porcelain is fired so hot that part of the clay turns to glass, which is why light shines through a thin cup.","answer":"Porcelain is made from kaolin blended with quartz and feldspar, shaped, then fired in a kiln at 1,200 to 1,400 °C. At that heat the body vitrifies and grows crystals of the mineral mullite. That gives the ware its strength, its whiteness and its translucence.","aka":["china","fine china","bone china","hard-paste porcelain"],"inputs":["kaolin","quartz","feldspar","pigment"],"uses":["snow-globe"],"grounds":["kaolin","quartz","feldspar","iron-ore","sulfur","titanium-ore","crude-oil","air","water","rock-salt","coal"],"upstreamSlugs":["kaolin","quartz","feldspar","pigment","iron-ore","titanium-dioxide","carbon-black","sulfur","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","crude-oil","air","water","rock-salt","coal"],"downstreamSlugs":["snow-globe"],"steps":[{"name":"Blend the porcelain body","process":"mix","text":"Kaolin is the key clay, though clay minerals may be only a small part of the whole. Formulations combine kaolin with quartz and feldspar. English bone china traditionally used two parts bone ash, one part kaolin and one part china stone.","inputs":["kaolin","quartz","feldspar"]},{"name":"Shape the ware","process":"mold","text":"Porcelain is formed by throwing, by slip casting in plaster molds, or by pressing. It is harder to work than earthenware because the paste has less natural plasticity.","inputs":[]},{"name":"Fire the biscuit","process":"fire","text":"Modern porcelains are biscuit-fired at around 1,000 °C. The first firing firms the ware enough to be handled and dipped in glaze.","inputs":[],"spec":"around 1,000 °C"},{"name":"Dip it in glaze","process":"coat","text":"Porcelain needs no glaze to be watertight, because the body is already vitrified. Glaze mostly adds decoration and resistance to dirt and staining.","inputs":[]},{"name":"Fire it hot to vitrify","process":"fire","text":"The glaze firing goes to about 1,300 °C or greater. The body vitrifies and grows interlocking needles of mullite, which gives the strength and the translucence.","inputs":[],"spec":"1,200–1,400 °C"},{"name":"Decorate with enamels","process":"print","text":"Delicate pigments go on over the glaze as overglaze enamels, then ware is fired again at a lower heat so they do not burn off.","inputs":["pigment"]}],"facts":["The Meissen factory made the first European porcelain, and its kiln reached up to 1,400 °C.","The word porcelain comes from the old Italian porcellana, which means cowrie shell.","Song dynasty dragon kilns could fire as many as 25,000 pieces at a time."],"where":[],"whereNote":null,"sources":[{"title":"Porcelain","url":"https://en.wikipedia.org/wiki/Porcelain"},{"title":"Pottery","url":"https://en.wikipedia.org/wiki/Pottery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"port-wine","name":"Port wine","kind":"product","category":"drink","title":"How port wine is made","url":"https://assemblyline.org/make/port-wine","stations":6,"upstream":44,"downstream":0,"depth":6,"dek":"Port is red wine whose fermentation is stopped halfway by pouring in grape spirit, which leaves the sugar behind.","answer":"Port is a fortified wine from the Douro Valley in Portugal. Red grapes ferment into wine, and before the yeast has eaten all the sugar a neutral grape spirit is added. That stops the fermentation, leaves natural sweetness and lifts the alcohol to between 19 and 22 percent. The wine is then aged in tanks or oak barrels.","aka":["vinho do Porto","fortified wine"],"inputs":["grapes","yeast","ethanol","wine-barrel","glass-bottle"],"uses":[],"grounds":["grapes","water","corn","sugarcane","timber","silica-sand","limestone","sugar-beet","natural-gas","rock-salt","trona","crude-oil","iron-ore","air","dolomite","manganese-ore","coal","quartz","sulfur"],"upstreamSlugs":["grapes","yeast","ethanol","wine-barrel","glass-bottle","water","molasses","corn","sugarcane","ethylene","timber","steel","silica-sand","soda-ash","limestone","polyethylene","sugar-beet","naphtha","natural-gas","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","rock-salt","ammonia","carbon-dioxide","trona","crude-oil","hydrogen","iron-ore","coke","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","coal","quartz","charcoal","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Harvest Douro grapes","process":"harvest","text":"Port may only be made from grapes grown in the demarcated Douro region, whose terraced estates, called quintas, cling to steep slopes above the river.","inputs":["grapes"]},{"name":"Ferment the wine","process":"ferment","text":"The grape juice is fermented, and the yeast starts turning its sugar into alcohol.","inputs":["yeast"]},{"name":"Stop it with spirit","process":"mix","text":"A neutral grape spirit called aguardente is added to the fermenting wine. The spirit stops the fermentation early, which leaves residual sugar in the wine and raises its alcohol level.","inputs":["ethanol"]},{"name":"Age in tank or barrel","process":"dry","text":"Ruby ports rest in concrete or stainless steel tanks to keep their bright red color. Tawny ports age in wooden barrels, where slow oxidation and evaporation turn them golden brown and nutty.","inputs":["wine-barrel"]},{"name":"Blend, fine and filter","process":"separate","text":"The wine is blended to match the house style of each brand, then fined and cold filtered before bottling.","inputs":[]},{"name":"Bottle it","process":"fill","text":"Port is filled into glass bottles. Vintage ports are designed to keep aging in the bottle for 10 to 40 years or more.","inputs":["glass-bottle"]}],"facts":["The Douro is the third oldest protected wine region in the world, after Chianti and Tokaj.","Until 1986 port could only be exported from Vila Nova de Gaia, near Porto.","Vintage port, the most famous kind, is only about 2 percent of all port made."],"where":[],"whereNote":null,"sources":[{"title":"Port wine","url":"https://en.wikipedia.org/wiki/Port_wine"},{"title":"Wine","url":"https://en.wikipedia.org/wiki/Wine"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"potash","name":"Potash","kind":"raw","category":"ground","title":"How potash is mined","url":"https://assemblyline.org/make/potash","stations":3,"upstream":0,"downstream":5,"depth":0,"dek":"Potash is named for ash boiled in a pot. Today it is dug from beds left by seas that dried up long ago.","answer":"Potash is a family of potassium salts, mostly potassium chloride, found in underground beds where ancient inland seas evaporated. Mines cut the ore from those beds, and mills crush it and separate the potassium salt from the common salt mixed through it. Most of it goes to farms as fertilizer.","aka":["potassium chloride","sylvite","muriate of potash"],"inputs":[],"uses":["fertilizer","smartphone-glass","potassium-hydroxide"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["fertilizer","smartphone-glass","potassium-hydroxide","smartphone","aa-battery"],"steps":[{"name":"Mine the buried salt beds","process":"mine","text":"Potash ore is a natural mixture of sylvite, which is potassium chloride, and halite, which is table salt. The beds lie underground, covered over by later rock, and are reached by shafts.","inputs":[]},{"name":"Crush the ore","process":"crush","text":"Ore is brought to the surface and crushed so the potassium and sodium salts can be told apart.","inputs":[]},{"name":"Split the potash from salt","process":"separate","text":"Plants separate the potassium salt from the sodium chloride and clay, then grade it by particle size. Most is sold as fertilizer.","inputs":[]}],"facts":["The word potash comes from pot ash, plant ashes soaked in water in a pot.","Potash was mined in Ethiopia from the 14th century, and the Dallol area still holds a deposit of 140 to 150 million tons."],"where":[{"place":"Canada","share":"largest producer"},{"place":"Russia","share":"other major producer"},{"place":"Belarus","share":"other major producer"}],"whereNote":"Ranking by potash output in 2021, when world production exceeded 71.9 million tonnes.","sources":[{"title":"Potash","url":"https://en.wikipedia.org/wiki/Potash"},{"title":"Halite","url":"https://en.wikipedia.org/wiki/Halite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"potassium-hydroxide","name":"Potassium hydroxide","kind":"material","category":"chemicals","title":"How potassium hydroxide is made","url":"https://assemblyline.org/make/potassium-hydroxide","stations":5,"upstream":2,"downstream":1,"depth":1,"dek":"Caustic potash was once made by stirring potash into slaked lime. Now current through brine does it.","answer":"Potassium hydroxide is produced by electrolysis of potassium chloride solution, in cells that keep the two electrodes apart. Hydrogen and chlorine form as by-products at the electrodes. The liquor is boiled down, and the product is sold as flakes, pellets or solution. About 2.5 million tonnes were made in 2023.","aka":["caustic potash","KOH","lye"],"inputs":["potash","water"],"uses":["aa-battery"],"grounds":["potash","water"],"upstreamSlugs":["potash","water"],"downstreamSlugs":["aa-battery"],"steps":[{"name":"Dissolve potassium chloride","process":"mix","text":"Potash salt is dissolved in water to make a brine. The brine is purified before it goes to the cells.","inputs":["potash","water"]},{"name":"Run current through the cell","process":"electrolyze","text":"Electrolysis gives potassium hydroxide in solution, hydrogen at the cathode and chlorine at the anode. The anode and cathode spaces must be kept apart.","inputs":[]},{"name":"Boil the liquor down","process":"cook","text":"The caustic solution is evaporated to a stronger concentration. Most commercial grades are about 90 percent pure, with the rest water and carbonates.","inputs":[],"spec":"about 90% pure"},{"name":"Melt-cast it into pellets","process":"cast","text":"The molten caustic is cast into pellets or rods. They pick up moisture from air and turn tacky, so they are sealed in drums at once.","inputs":[]},{"name":"Pack by purity grade","process":"package","text":"Industrial and food uses need at least 90 percent purity. Food grade also has strict arsenic and lead limits.","inputs":[]}],"facts":["Until the late 19th century caustic potash came from mixing potash with slaked lime and filtering off the chalk, a method electrolysis replaced.","Potassium hydroxide is the precursor to most soft and liquid soaps.","It is used in cocoa processing and to debitter olives."],"where":[],"whereNote":null,"sources":[{"title":"Potassium hydroxide","url":"https://en.wikipedia.org/wiki/Potassium_hydroxide"},{"title":"Hydrochloric acid","url":"https://en.wikipedia.org/wiki/Hydrochloric_acid"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"potato-chips","name":"Potato chips","kind":"product","category":"food","title":"How potato chips are made","url":"https://assemblyline.org/make/potato-chips","stations":7,"upstream":15,"downstream":0,"depth":4,"dek":"Chip potatoes are picked for low sugar, because sugar would scorch the slices brown in the fryer.","answer":"Potatoes are washed, peeled and sliced paper-thin, then rinsed to remove surface starch. The slices ride through a bath of hot oil on a conveyor or are stirred in batch kettles. After frying, they are drained, salted and seasoned, then bagged with nitrogen to keep them crisp and unbroken.","aka":["crisps","potato crisps","kettle chips"],"inputs":["potatoes","water","vegetable-oil","table-salt","nitrogen"],"uses":[],"grounds":["potatoes","water","soybeans","rapeseed","clay","rock-salt","seawater","air","crude-oil","natural-gas"],"upstreamSlugs":["potatoes","water","vegetable-oil","table-salt","nitrogen","soybeans","rapeseed","hexane","clay","rock-salt","seawater","air","crude-oil","hydrogen","natural-gas"],"downstreamSlugs":[],"steps":[{"name":"Wash and peel the potatoes","process":"wash","text":"Potatoes tumble in washers that scrub off soil and abrasive rollers that remove the skin. Chip potatoes are chosen for high solids and low sugar so they brown golden and do not scorch.","inputs":["potatoes","water"]},{"name":"Slice them very thin","process":"cut","text":"A spinning head pushes the potatoes against blades, and thin slices fly off. Some brands use ridged blades for a wavy chip.","inputs":[]},{"name":"Rinse off the starch","process":"wash","text":"Slices are rinsed with cold water. Without rinsing, loose starch would glue the chips together in the fryer. Batch makers rinse for the same reason.","inputs":[]},{"name":"Fry in hot oil","process":"cook","text":"In a continuous process, the slices are carried through a vat of hot oil on a conveyor. In the older batch process for kettle chips, slices were fried at a low temperature of about 150 °C and raked constantly to prevent sticking.","inputs":["vegetable-oil"],"spec":"about 150 °C for kettle batches"},{"name":"Shake off the oil","process":"dry","text":"Chips leave the fryer on a mesh belt and drain. Crisp chips are carefully watched for dark spots, since fried and baked potatoes at high temperatures produce acrylamide.","inputs":[]},{"name":"Salt and season","process":"coat","text":"Chips tumble in a slowly turning drum while salt and seasoning powder are dusted over them. Flavors such as ketchup can be added in the same drum.","inputs":["table-salt"]},{"name":"Bag with nitrogen","process":"fill","text":"Weighers drop each portion into a bag. Nitrogen is flushed through, which cushions the chips and keeps oxygen away.","inputs":["nitrogen"]}],"facts":["The earliest known potato chip recipe is in William Kitchiner's 1817 cookbook The Cook's Oracle.","The popular story of George Crum inventing chips at Saratoga Springs is today known to be untrue."],"where":[],"whereNote":null,"sources":[{"title":"Potato chip","url":"https://en.wikipedia.org/wiki/Potato_chip"},{"title":"French fries","url":"https://en.wikipedia.org/wiki/French_fries"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"potatoes","name":"Potatoes","kind":"raw","category":"farm","title":"How potatoes are grown and harvested","url":"https://assemblyline.org/make/potatoes","stations":4,"upstream":0,"downstream":3,"depth":0,"dek":"Potatoes are stems, not roots, and sunlight turns them green and toxic, so growers pile soil over them.","answer":"Potatoes are grown from certified seed potatoes, tubers raised to be disease-free, planted in rows. New tubers swell at the tips of underground stolons, and growers pile soil up around the plants so light does not turn them green. Harvesters scoop up the plant and the soil, then shake the soil away from the tubers.","aka":["potato farming","potato harvest","spuds","tubers"],"inputs":[],"uses":["potato-chips","french-fries","vodka"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["potato-chips","french-fries","vodka"],"steps":[{"name":"Plant seed potatoes","process":"grow","text":"Potatoes are grown from seed potatoes, tubers raised specifically to be disease-free and give healthy, consistent plants. Sprouts emerge and roots form, then the plant puts out leaves above ground.","inputs":[]},{"name":"Hill up the rows","process":"grow","text":"Tubers that form near the surface and see light turn green and develop solanine, a toxin. Growers pile additional soil around the base of the plant, called hilling or earthing up, to keep the tubers covered.","inputs":[]},{"name":"Dig and shake out the tubers","process":"harvest","text":"A commercial harvester scoops up the plant and surrounding earth onto a steel apron chain that separates out soil. More complex designs add vine choppers, shakers and blowers.","inputs":[]},{"name":"Cure for skin-set","process":"dry","text":"Potatoes are usually cured after harvest so the skin resists scuffing and wounds heal. That prevents infection and water loss in storage.","inputs":[]}],"facts":["There are over 5,000 varieties of potato, and Peru alone grows around 3,000 of them.","After flowering, potato plants produce small green fruits like cherry tomatoes, each holding about 300 tiny seeds.","The potato is in the same genus as the tomato, Solanum, and its leaves and stems contain the toxin solanine."],"where":[{"place":"China","share":"24% of world output"},{"place":"India","share":"major secondary producer"}],"whereNote":"2024, share of the 390 million tonnes of potatoes produced worldwide.","sources":[{"title":"Potato","url":"https://en.wikipedia.org/wiki/Potato"},{"title":"Seed potato","url":"https://en.wikipedia.org/wiki/Seed_potato"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"powdered-milk","name":"Powdered milk","kind":"product","category":"food","title":"How powdered milk is made","url":"https://assemblyline.org/make/powdered-milk","stations":6,"upstream":1,"downstream":4,"depth":1,"dek":"A tall chamber of air heated to 150 to 250 °C turns a fine spray of milk into powder almost instantly.","answer":"Milk is pasteurized, then boiled down in an evaporator until it is about half milk solids. This thick concentrate is sprayed into a heated chamber, where the water vanishes almost instantly and tiny dry particles of milk solids fall out. An older route scrapes the milk off a heated drum.","aka":["milk powder","dried milk","dry milk","nonfat dry milk"],"inputs":["raw-milk"],"uses":["chocolate","hazelnut-spread","white-chocolate"],"grounds":["raw-milk"],"upstreamSlugs":["raw-milk"],"downstreamSlugs":["chocolate","hazelnut-spread","white-chocolate","candy-coated-chocolate"],"steps":[{"name":"Skim off the cream","process":"separate","text":"For nonfat powder the cream is spun out of the milk first. Whole milk powder keeps its fat, and buttermilk and whey can also be dried the same way.","inputs":["raw-milk"]},{"name":"Pasteurize the milk","process":"pasteurize","text":"Heat kills the harmful microbes. How hard the milk is heated here changes how well the finished powder dissolves, how it tastes and how densely it packs.","inputs":[]},{"name":"Boil off half the water","process":"refine","text":"An evaporator concentrates the milk until it is about 50 percent milk solids. Removing water this way takes only about 10 to 12 percent of the energy spray drying needs.","inputs":[],"spec":"about 50% milk solids"},{"name":"Spray into hot air","process":"dry","text":"High-pressure nozzles or a spinning disc throw the concentrate into a heated chamber. Each droplet loses its free water at once and leaves behind a fine particle of dry milk solids.","inputs":[],"spec":"air at 150 to 250 °C"},{"name":"Finish on a fluid bed","process":"dry","inputs":[],"text":"Many plants let the powder leave the chamber slightly damp and finish it on a vibrating bed where air blows up through a plate full of fine holes. Cyclones and bag filters catch the dust from the exhaust."},{"name":"Pack it airtight","process":"package","text":"Dry powder keeps far longer than liquid milk and needs no refrigeration, but damp air and warm storage can degrade it, so it goes into sealed bags and cans.","inputs":[]}],"facts":["The first modern process for drying milk was invented by a Russian doctor in 1802.","Drum-dried powder tastes cooked, because the milk sugars caramelize in the heat of the drum.","As of 2021, the largest producers of milk powder were New Zealand, China, Argentina and Brazil."],"where":[],"whereNote":null,"sources":[{"title":"Powdered milk","url":"https://en.wikipedia.org/wiki/Powdered_milk"},{"title":"Condensed milk","url":"https://en.wikipedia.org/wiki/Condensed_milk"},{"title":"Milk and whey powder, Dairy Processing Handbook","url":"https://dairyprocessinghandbook.tetrapak.com/chapter/milk-and-whey-powder"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"power-cable","name":"Power cable","kind":"product","category":"electronics","title":"How power cables are made","url":"https://assemblyline.org/make/power-cable","stations":9,"upstream":26,"downstream":0,"depth":6,"dek":"Edison's first cables of 1882 were copper rods wrapped in jute, in pipes filled with a bituminous compound.","answer":"Copper is drawn through diamond dies into thin wires, and many wires are stranded into a flexible conductor. An extruder melts plastic granules and forms a layer around the strand, which is cooled in a water bath. Insulated cores are twisted together into a bundle, sometimes braided in tinned copper, and sheathed by a second extrusion. Each length is printed, then tested at high voltage in a Faraday cage.","aka":["electrical cable","mains cable"],"inputs":["copper-wire","polyethylene","pvc"],"uses":[],"grounds":["water","copper-ore","air","natural-gas","rock-salt","iron-ore","sulfur","crude-oil","titanium-ore","coal"],"upstreamSlugs":["copper-wire","polyethylene","pvc","copper","ethylene","chlorine","water","pigment","plasticizer","copper-ore","oxygen","air","sulfuric-acid","naphtha","natural-gas","rock-salt","iron-ore","titanium-dioxide","carbon-black","sulfur","propylene","crude-oil","hydrogen","titanium-ore","coke","coal"],"downstreamSlugs":[],"steps":[{"name":"Draw the copper","process":"draw","text":"Copper is pulled through diamond dies on drawing machines until it is thin wire. The wire gets longer and finer with each die.","inputs":["copper-wire"]},{"name":"Strand the conductor","process":"spin","text":"Fine wires are twisted into a strand. The class of strand chosen here sets how flexible the finished cable will be.","inputs":[]},{"name":"Extrude the insulation","process":"extrude","text":"Plastic and color granules feed from hoppers into a heated screw that melts them. In the head, the melt forms around the passing copper strand.","inputs":["polyethylene"],"spec":"up to 240 °C, in some cases 300 °C"},{"name":"Cool in water","process":"chill","text":"The insulated wire runs through a water bath until it is cool to the core, so turns do not stick together on the drum.","inputs":[]},{"name":"Strand the cores","process":"spin","text":"Colored or numbered cores feed into a stranding machine in set sequence, and rotary motion brings them together into a kind of cord. Stuttgart's tube strander is 50 m long.","inputs":[]},{"name":"Braid the shield","process":"weave","text":"Servo and control cables get an inner jacket and then a tinned copper braid against electrical interference and mechanical load. The braid covers 80 to 85 % of the surface.","inputs":["copper-wire"]},{"name":"Extrude the outer sheath","process":"extrude","text":"A second extruder lays on the protective plastic sheath, with a fleece winding underneath so it does not stick to the core.","inputs":["pvc"]},{"name":"Print the legend","process":"print","text":"Type, specifications and traceability marks are printed along the sheath as it passes.","inputs":[]},{"name":"Test at high voltage","process":"inspect","text":"In a Faraday cage, simulated short circuits at up to 6,000 V check insulation between wires and against the shield. Passed cable is rewound onto wooden reels.","inputs":[]}],"facts":["Thomas Edison's first power distribution system in 1882 in New York City used copper rods wrapped in jute and placed in rigid pipes filled with a bituminous compound.","Mass-impregnated paper-insulated medium-voltage cables were commercially practical by 1895.","Armored cable, known as BX, was introduced in 1906 with a flexible steel sheath around rubber-insulated conductors."],"where":[],"whereNote":null,"sources":[{"title":"Industrial Production: Cable production, how a cable is made at Lapp","url":"https://www.industrial-production.de/electromechanics/cable-production-how-a-cable-is-made.htm"},{"title":"Anzer: Manufacturing wires and cables, 10 basics","url":"https://www.anzer-usa.com/resources/?p=1374"},{"title":"Power cable","url":"https://en.wikipedia.org/wiki/Power_cable"},{"title":"Wire drawing","url":"https://en.wikipedia.org/wiki/Wire_drawing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"power-outlet","name":"Power outlet","kind":"product","category":"electronics","title":"How wall power outlets are made","url":"https://assemblyline.org/make/power-outlet","stations":6,"upstream":47,"downstream":0,"depth":7,"dek":"Wall sockets arrived in the 1880s so appliances no longer had to be wired into a light fixture.","answer":"Springy contacts start as copper or brass sheet in a high-speed press, which punches, bends and can rivet them in one run. Injection molding machines form the plastic body, at one plant with robot arms placing copper inserts. Assembly lines fit the contacts and terminal screws, and inspections at several stages catch faults before the outlets ship.","aka":["electrical outlet","wall socket","receptacle"],"inputs":["brass","copper","plastic","screw"],"uses":[],"grounds":["copper-ore","water","air","natural-gas","zinc-ore","lead-ore","tin-ore","crude-oil","coal","sulfur","bauxite","rock-salt","limestone","iron-ore","dolomite","manganese-ore","quartz","timber"],"upstreamSlugs":["brass","copper","plastic","screw","zinc","lead","tin","aluminum","copper-ore","water","oxygen","air","sulfuric-acid","naphtha","natural-gas","ethylene","propylene","steel-wire","zinc-ore","lead-ore","coke","tin-ore","crude-oil","coal","petroleum-coke","alumina","sulfur","hydrogen","steel","bauxite","caustic-soda","lime","pig-iron","magnesium","steel-scrap","manganese","argon","rock-salt","limestone","iron-ore","dolomite","silicon","propane","manganese-ore","quartz","charcoal","timber"],"downstreamSlugs":[],"steps":[{"name":"Stamp the contacts","process":"stamp","text":"A press punches the clips and terminals from metal sheet through a fast continuous die. One supplier holds errors to within 0.01 to 0.05 millimeters, which keeps plug insertion and removal force under control.","inputs":["brass","copper"]},{"name":"Bend and rivet the clips","process":"press","text":"The same die run bends each clip and can rivet parts together. Fewer gaps between pieces mean less oxidation and loosening later.","inputs":[]},{"name":"Turn the heavy pins","process":"machine","text":"Larger industrial sockets can use machined parts. A maker in Wenzhou, China, turns brass pins and sockets on automatic lathes, with 16A and 32A parts on its high-speed machines.","inputs":["brass"]},{"name":"Mold the housing","process":"mold","text":"Plastic is injected into molds to form the face and body. The Wenzhou plant runs 50 machines from a central feed of flame-retardant engineering plastic, with five-axis robot arms placing copper inserts and chilled water cooling the work.","inputs":["plastic"]},{"name":"Fit parts together","process":"assemble","text":"Contacts are fitted in the body, terminal screws go in, and the face is fixed on. Modern plants run this on assembly lines, and the Wenzhou maker describes its assembly as automated.","inputs":["screw"]},{"name":"Inspect at every stage","process":"inspect","text":"Inspections run at several points in production, so a bad socket is caught early and corrected. Safety tests come first in design and carry on through manufacturing, because an electrical failure can do serious harm.","inputs":[]}],"facts":["In the 1880s, appliances stopped borrowing light fittings once the first wall sockets and plugs reached the market.","Commercial electric power was sold mainly for lighting at first, which is why the earliest appliances connected to light sockets."],"where":[],"whereNote":null,"sources":[{"title":"AC power plugs and sockets","url":"https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets"},{"title":"Brass","url":"https://en.wikipedia.org/wiki/Brass"},{"title":"Analysis of Switch Socket Precision Custom Metal Stamping Parts","url":"https://www.stamping-welding.com/info/analysis-of-switch-socket-precision-custom-met-103532547.html"},{"title":"Stamping Riveting Electrical Copper Press Parts For Switch Sockets","url":"https://www.china-electronic-components.com/news/stamping-riveting-electrical-copper-press-part-85540537.html"},{"title":"Factory Show & Manufacturing Capacity (Kripal)","url":"https://www.kripal.net/?p=163"},{"title":"From Concept to Reality: The Journey of electric wall socket Development","url":"https://www.paclights.com/?p=40500"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pressure-cooker","name":"Pressure cooker","kind":"product","category":"hardware","title":"How pressure cookers are made","url":"https://assemblyline.org/make/pressure-cooker","stations":8,"upstream":44,"downstream":0,"depth":7,"dek":"A pressure cooker has a calibrated release valve and at least one emergency valve, so the steam always has an exit.","answer":"A pressure cooker body is deep-drawn from a flat metal disc into a one-piece pot, and layers of aluminum are impact-bonded to its bottom to spread heat. The lid is pressed with locking edges that grip the rim, and a gasket seals it. Valves are fitted, and each unit is pressure tested.","aka":["pressure pot","stovetop pressure cooker"],"inputs":["stainless-steel","aluminum","silicone"],"uses":[],"grounds":["crude-oil","coal","water","silica-sand","chromite","limestone","air","nickel-ore","bauxite","quartz","timber","natural-gas","rock-salt","trona","sulfur","corn","sugarcane","sugar-beet"],"upstreamSlugs":["stainless-steel","aluminum","silicone","steel-scrap","chromium","nickel","oxygen","argon","crude-oil","coal","petroleum-coke","alumina","silicon","methanol","hydrochloric-acid","water","silica-sand","propane","chromite","coke","soda-ash","limestone","air","nickel-ore","sulfuric-acid","bauxite","caustic-soda","lime","quartz","charcoal","timber","natural-gas","chlorine","hydrogen","rock-salt","ammonia","carbon-dioxide","trona","sulfur","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut discs from coil","process":"cut","text":"Coils of stainless steel or aluminum are checked and blanked into flat round discs.","inputs":["stainless-steel"]},{"name":"Draw the deep pot","process":"draw","text":"A hydraulic press forces each disc into a die and draws it into a one-piece pot with no side seam.","inputs":[]},{"name":"Trim and bead the rim","process":"machine","text":"Excess metal is trimmed from the edge and the rim is reinforced, so it can seal against the lid.","inputs":[]},{"name":"Impact-bond the base","process":"press","text":"Layers of aluminum and magnetic steel are slammed onto the bottom under enormous pressure. They fuse, so the heat spreads evenly and the base will not warp.","inputs":["aluminum"]},{"name":"Form the lid and lugs","process":"stamp","text":"The lid is pressed in several steps. The rim of the pot and the lid are shaped with matching lugs so that a quarter turn locks them.","inputs":[]},{"name":"Polish and clean","process":"grind","text":"Polishing wheels give the mirror or satin finish, and an ultrasonic bath strips off oils and polishing residue.","inputs":[]},{"name":"Fit the gasket and valves","process":"assemble","text":"A sealing ring goes into the lid to seal the gap. A calibrated pressure valve is added, plus at least one emergency valve.","inputs":["silicone"]},{"name":"Pressure test each unit","process":"inspect","text":"Each finished cooker is pressurized to check the body and lid, and the valves are tested for the exact pressure at which they release.","inputs":[]}],"facts":["The ancestor of the pressure cooker was the steam digester, invented in the seventeenth century by the physicist Denis Papin.","At one bar above atmospheric pressure, water inside reaches about 120 degrees Celsius.","In 1950, 37 percent of US households owned a pressure cooker, but by 2011 only 20 percent did, partly from fear of explosions."],"where":[],"whereNote":null,"sources":[{"title":"Pressure cooker","url":"https://en.wikipedia.org/wiki/Pressure_cooker"},{"title":"Stainless Steel Pressure Cooker Manufacturing Process","url":"https://www.linktonkitchen.com/stainless-steel-pressure-cooker-manufacturing-process/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pretzel","name":"Pretzel","kind":"product","category":"food","title":"How pretzels are made","url":"https://assemblyline.org/make/pretzel","stations":7,"upstream":33,"downstream":0,"depth":9,"dek":"Soft pretzels get their dark skin from a quick dip in a lye bath just before baking.","answer":"A lean yeast dough is rolled into a long rope and twisted into the knot. The knots are dipped or sprayed with a hot alkaline solution of lye or washing soda, sprinkled with coarse salt and baked. The alkali speeds the Maillard reaction on the surface, giving the deep brown color and the pretzel flavor.","aka":["soft pretzel","lye pretzel","Brezel","hard pretzel"],"inputs":["flour","water","yeast","table-salt","caustic-soda","baking-soda"],"uses":[],"grounds":["water","wheat","rock-salt","seawater","trona","limestone","air","sugarcane","sugar-beet","natural-gas","corn","crude-oil"],"upstreamSlugs":["flour","water","yeast","table-salt","caustic-soda","baking-soda","wheat","vitamin-c","molasses","rock-salt","seawater","trona","limestone","ammonia","soda-ash","carbon-dioxide","corn-starch","hydrogen","air","sugar","plastic-bottle","sugarcane","sugar-beet","natural-gas","lime","corn","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Mix a lean dough","process":"mix","text":"Flour, water, yeast and salt are mixed, with little or no sugar or fat. The dough is firm so the shape holds as the pretzel bakes.","inputs":["flour","water","yeast","table-salt"]},{"name":"Rest the dough","process":"ferment","text":"The dough rises briefly to build flavor and make it easy to handle. Pretzels are not proofed as fully as bread.","inputs":[]},{"name":"Extrude into ropes","process":"extrude","text":"Pieces of dough are rolled or extruded into ropes with tapered ends. The ropes have to be long and thin to make the traditional shape.","inputs":[]},{"name":"Twist the knot","process":"mold","text":"The ends of each rope are crossed over in a symmetrical form and pressed down onto the loop. Machines now twist pretzels at high speed, and the knot is the distinctive shape of the product.","inputs":[]},{"name":"Dip in the alkali bath","process":"coat","text":"The knots go through a warm solution of lye (sodium hydroxide). A weaker option is a baking soda solution. The alkali changes the chemistry of the dough surface so the crust browns and tastes like a pretzel. Factories handle the lye with strict safety controls.","inputs":["caustic-soda","baking-soda"]},{"name":"Salt and slash","process":"coat","text":"Coarse salt is sprinkled on top. Many soft pretzels are slashed across the thick part so the dough can open as it bakes.","inputs":["table-salt"]},{"name":"Bake dark","process":"bake","text":"A hot oven sets the shape and browns the skin through the Maillard reaction. Hard pretzels are baked again to dry them into crisp, long-keeping snacks.","inputs":[]}],"facts":["Pretzels have been a bakers' emblem in southern Germany since at least the 12th century.","The same lye dip makes other Bavarian lye pastries such as lye rolls and lye croissants."],"where":[],"whereNote":null,"sources":[{"title":"Pretzel","url":"https://en.wikipedia.org/wiki/Pretzel"},{"title":"Bread","url":"https://en.wikipedia.org/wiki/Bread"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"printed-circuit-board","name":"Printed circuit board","kind":"product","category":"electronics","title":"How printed circuit boards are made","url":"https://assemblyline.org/make/printed-circuit-board","stations":8,"upstream":48,"downstream":42,"depth":8,"dek":"A circuit board is glass cloth soaked in epoxy and clad in copper, with wiring left behind after acid eats the rest.","answer":"A printed circuit board is a sandwich of glass-epoxy sheets and copper foil. Light exposes a pattern on a resist, and acid eats away the unprotected copper to leave traces. Layers are pressed together, holes are drilled and plated, solder paste is printed, parts are placed by machine and a reflow oven melts the solder.","aka":["PCB","circuit board","printed wiring board","motherboard"],"inputs":["copper","fiberglass","epoxy","photoresist","solder"],"uses":["hearing-aid","pacemaker","thermometer","led-bulb","ev-battery","smartphone","laptop","television","hard-drive","solid-state-drive","computer-keyboard","computer-mouse","wind-turbine","microwave-oven","washing-machine","drone","satellite","car","electric-car","airbag","airplane","rocket","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","smoke-detector","smartwatch","wireless-earbuds","phone-charger","digital-camera","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush"],"grounds":["copper-ore","water","air","silica-sand","limestone","sulfur","rock-salt","trona","crude-oil","tin-ore","lead-ore","silver-ore","zinc-ore","natural-gas","corn","coal","sugarcane","sugar-beet"],"upstreamSlugs":["copper","fiberglass","epoxy","photoresist","solder","copper-ore","water","oxygen","air","sulfuric-acid","silica-sand","limestone","soda-ash","phenol","propylene","acetone","chlorine","caustic-soda","phenolic-resin","tin","lead","silver","sulfur","rock-salt","ammonia","carbon-dioxide","lime","trona","benzene","naphtha","crude-oil","formaldehyde","tin-ore","coke","lead-ore","zinc","silver-ore","zinc-ore","natural-gas","corn","yeast","hydrogen","toluene","methanol","coal","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["hearing-aid","pacemaker","thermometer","led-bulb","ev-battery","smartphone","laptop","television","hard-drive","solid-state-drive","computer-keyboard","computer-mouse","wind-turbine","microwave-oven","washing-machine","drone","satellite","car","electric-car","airbag","airplane","rocket","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","smoke-detector","smartwatch","wireless-earbuds","phone-charger","digital-camera","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","skyscraper"],"steps":[{"name":"Bond copper to glass-epoxy","process":"laminate","text":"Copper foil is laminated onto sheets of FR-4, a woven glass cloth soaked in epoxy. This is the most common base material for boards.","inputs":["copper","fiberglass","epoxy"]},{"name":"Expose the wiring pattern","process":"etch","text":"Photoresist is coated on the copper and exposed to light projected in the pattern of the artwork. Resist that remains protects the copper that will become wires.","inputs":["photoresist"]},{"name":"Etch away the extra copper","process":"etch","text":"The etching solution dissolves every unprotected part of the copper layer. The board is then cleaned, leaving traces, pads and solid planes.","inputs":[]},{"name":"Press the layers together","process":"laminate","text":"Multilayer boards stack several etched cores with insulating layers between them, so inner traces do not take up surface space.","inputs":["epoxy"]},{"name":"Drill and plate the vias","process":"machine","text":"Holes are drilled through the stack and lined with metal, linking one copper layer to another. Since 1995, microvias have let makers build denser boards.","inputs":["copper"]},{"name":"Cover with solder mask","process":"coat","text":"A protective coating goes over the traces except the pads, which reduces the chance of solder shorts.","inputs":[]},{"name":"Print solder paste","process":"print","text":"Solder paste, a sticky mix of powdered solder and flux, is printed onto the pads.","inputs":["solder"]},{"name":"Place parts and reflow","process":"weld","text":"Machines drop components onto the paste, then the board rides through a reflow oven. Each zone is set to a temperature profile until the paste melts into permanent joints, for anywhere from one to thousands of parts.","inputs":[]}],"facts":["Albert Hanson described flat foil conductors laminated to an insulating board in layers in 1903, long before anything we would call electronics was cheap.","A 4-layer board with microvias is considered equal in quality to an 8-layer through-hole board.","Thomas Edison experimented with plating conductors onto linen paper in 1904."],"where":[],"whereNote":null,"sources":[{"title":"Printed circuit board","url":"https://en.wikipedia.org/wiki/Printed_circuit_board"},{"title":"Reflow soldering","url":"https://en.wikipedia.org/wiki/Reflow_soldering"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"printer-toner","name":"Printer toner","kind":"product","category":"chemicals","title":"How printer toner is made","url":"https://assemblyline.org/make/printer-toner","stations":7,"upstream":22,"downstream":0,"depth":5,"dek":"Laser printer toner is mostly ground plastic, and the printer melts it onto the page.","answer":"Toner makers mix plastic resin with pigment and other additives, melt the blend, and cool it into a slab. The slab is broken up and jet-milled into a fine powder, sorted by size so every particle is about the same, and coated with tiny silica particles that help it flow and carry a static charge.","aka":["laser toner","toner powder","copier toner"],"inputs":["plastic","carbon-black","paraffin-wax","pigment"],"uses":[],"grounds":["natural-gas","crude-oil","air","water","iron-ore","sulfur","titanium-ore","rock-salt","coal"],"upstreamSlugs":["plastic","carbon-black","paraffin-wax","pigment","naphtha","natural-gas","ethylene","propylene","crude-oil","air","water","hydrogen","iron-ore","titanium-dioxide","sulfur","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","rock-salt","coal"],"downstreamSlugs":[],"steps":[{"name":"Mix resin and pigment","process":"mix","text":"A plastic resin, often polyester or a styrene acrylate, is blended with pigment, wax and a charge-control additive. Black toner gets carbon black, and color toners get cyan, magenta and yellow pigments.","inputs":["plastic","carbon-black","paraffin-wax","pigment"]},{"name":"Melt-knead the blend","process":"melt","text":"A heated twin-screw extruder melts the resin and kneads the pigment all the way through it, so each future particle holds the same color.","inputs":[]},{"name":"Cool and break the slab","process":"chill","text":"The hot compound comes out as a ribbon and is cooled until brittle, then broken or chopped into small chunks.","inputs":[]},{"name":"Jet-mill to a powder","process":"crush","text":"Streams of air throw the pieces at one another at high speed. Toner resin is brittle, so the collisions shatter it into a fine powder.","inputs":[]},{"name":"Sort by size","process":"separate","text":"Air classifiers spin the powder and sort it by size. Particles that are too big go back to the mill, and dust that is too fine is removed.","inputs":[],"spec":"about 5 μm for 600 dpi"},{"name":"Coat with silica","process":"mix","text":"A high-speed blender sticks very fine fumed silica particles to the surface of the grains. This helps the powder flow and take on an electrical charge.","inputs":[]},{"name":"Screen and fill cartridges","process":"fill","text":"A vibrating screen takes out lumps, and the powder is filled into sealed cartridges.","inputs":[]}],"facts":["To print crisply at 600 dots per inch you need particles of about 5 micrometers, and at 1200 dpi about 3 micrometers.","Some makers grow toner particles chemically from molecules instead of grinding, which gives rounder particles of more even size.","Toner should never be cleaned up with a household vacuum, because the fine powder blows through the filter bag and back into the room."],"where":[],"whereNote":null,"sources":[{"title":"Toner (printing)","url":"https://en.wikipedia.org/wiki/Toner_(printing)"},{"title":"Laser printing","url":"https://en.wikipedia.org/wiki/Laser_printing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"propane","name":"Propane","kind":"product","category":"chemicals","title":"How propane is made","url":"https://assemblyline.org/make/propane","stations":5,"upstream":2,"downstream":169,"depth":1,"dek":"Propane is a by-product, caught from natural gas and from oil refining, and a smell is added so leaks are noticed.","answer":"Nobody drills for propane. It is separated as a by-product of natural gas processing and petroleum refining, then compressed into a liquid for storage and transport. The gas has no smell, so suppliers add ethyl mercaptan, which smells like rotten eggs, to make leaks easy to detect.","aka":["LPG","liquid petroleum gas","bottled gas"],"inputs":["natural-gas","crude-oil"],"uses":["steel-scrap","refrigerant","air-freshener","hairspray"],"grounds":["natural-gas","crude-oil"],"upstreamSlugs":["natural-gas","crude-oil"],"downstreamSlugs":["steel-scrap","refrigerant","air-freshener","hairspray","steel","stainless-steel","rebar","cast-iron-pan","refrigerator","air-conditioner","asthma-inhaler","toothbrush","lithium-ion-cell","ev-battery","aa-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","inkjet-printer","electric-toothbrush","syringe","washing-machine","electric-kettle","kitchen-knife","fork","razor-blade","fountain-pen","thermos","water-bottle","pressure-cooker","blender","smartwatch","concrete","skyscraper","smartphone","laptop","drone","satellite","wireless-earbuds","digital-camera","e-reader","electric-car","microwave-oven","treadmill","game-console","graphics-card","phone-charger","safety-pin","car","airbag","ceiling-fan","water-heater","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sailboat","action-figure","power-outlet","champagne","pencil","mirror","golf-ball","wallpaper","wooden-chair","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","snow-globe","neon-sign","aluminum-window-frame","toffee"],"steps":[{"name":"Strip liquids from raw gas","process":"separate","text":"Raw natural gas carries heavier hydrocarbons such as propane, butane and pentanes, collectively called natural gas liquids. Plants pull these out to produce pipeline quality gas.","inputs":["natural-gas"]},{"name":"Catch it at the refinery","process":"refine","text":"Petroleum refining also releases propane while making gasoline. Walter Snelling developed ways to liquefy these gases during refining in the early 1910s.","inputs":["crude-oil"]},{"name":"Fractionate the liquids","process":"refine","text":"Distillation columns split the mixed liquids into pure propane and other products. Propane boils at only -42 °C.","inputs":[]},{"name":"Add the warning smell","process":"mix","text":"The colorless, odorless gas gets a small dose of ethyl mercaptan so leaks can be sniffed out.","inputs":[]},{"name":"Compress into tanks","process":"fill","text":"Under modest pressure propane becomes a liquid, so it can be stored in cylinders and transported. Tanks are never filled completely, because the liquid expands as it warms.","inputs":[]}],"facts":["Because propane boils at -42 °C, it vaporizes inside a pressurized tank even in cold weather.","French chemist Marcellin Berthelot first made propane in 1857, and Edmund Ronalds found it dissolved in Pennsylvanian crude oil in 1864.","The propane industry dates to 1910, when Walter Snelling of the US Bureau of Mines flagged it as a volatile part of gasoline."],"where":[],"whereNote":null,"sources":[{"title":"Propane","url":"https://en.wikipedia.org/wiki/Propane"},{"title":"Natural-gas processing","url":"https://en.wikipedia.org/wiki/Natural-gas_processing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"propylene","name":"Propylene","kind":"material","category":"chemicals","title":"How propylene is made","url":"https://assemblyline.org/make/propylene","stations":5,"upstream":5,"downstream":304,"depth":3,"dek":"Propylene is mostly a byproduct, shaken out of a steam cracker or of the refinery unit that makes gasoline.","answer":"Propylene is mostly a coproduct. A steam cracker making ethylene from naphtha also produces propylene, and a refinery's fluid catalytic cracker releases it as a gas while turning heavy oil into gasoline. In both cases, the gas is compressed, chilled and distilled apart from its neighbors.","aka":["propene","C3H6"],"inputs":["naphtha","crude-oil"],"uses":["polypropylene","abs-plastic","acrylic","polycarbonate","epoxy","polyurethane","carbon-fiber","phenol","pvb","plastic","acrylic-acid","plasticizer","acetone"],"grounds":["crude-oil","water","natural-gas"],"upstreamSlugs":["naphtha","crude-oil","water","hydrogen","natural-gas"],"downstreamSlugs":["polypropylene","abs-plastic","acrylic","polycarbonate","epoxy","polyurethane","carbon-fiber","phenol","pvb","plastic","acrylic-acid","plasticizer","acetone","toothbrush","deodorant","mascara","syringe","electric-kettle","plastic-straw","clear-tape","dishwasher","office-chair","frisbee","sanitary-pad","cotton-swab","wet-wipes","dental-floss","prosthetic-leg","car-battery","suitcase","loudspeaker","baseball-cap","carpet","rope","diaper","n95-mask","lipstick","hearing-aid","thermometer","lego-brick","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","ballpoint-pen","snowboard","action-figure","harmonica","globe","high-heels","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","paint","adhesive","lcd-screen","sunglasses","lacquer","led-bulb","drone","eyeglass-lens","bike-helmet","blender","smartwatch","digital-camera","camera-lens","compact-disc","printed-circuit-board","wind-turbine","electric-motor","rebar","aluminum-can","airplane","surfboard","ski","tennis-racket","fishing-rod","umbrella","adhesive-bandage","pacemaker","refrigerator","car","skateboard","golf-ball","soccer-ball","hardwood-floor","water-heater","sofa","roller-skates","volleyball","bowling-ball","wheelchair","underwear","leggings","swimsuit","raincoat","backpack","sneaker","mattress","satellite","bicycle","golf-club","kite","aspirin","acetaminophen","billiard-ball","brake-pad","phenolic-resin","windshield","duct-tape","led","aa-battery","solar-panel","washing-machine","vacuum-cleaner","nonstick-pan","marker-pen","highlighter","fountain-pen","printer-toner","toaster","dice","yo-yo","board-game","jigsaw-puzzle","trading-cards","snow-globe","toy-car","tampon","asthma-inhaler","light-switch","power-outlet","smoke-detector","seat-belt","eyeglass-frame","microphone","superabsorbent-polymer","nail-polish","pvc","yoga-mat","hairspray","vinyl-floor","cellulose-acetate","shoelace","microwave-oven","pencil","scissors","mirror","electric-car","container-ship","shipping-container","locomotive","motorcycle","wallpaper","wooden-chair","water-bottle","ceiling-fan","dartboard","fashion-doll","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","subway-train","leather-belt","credit-card","ev-battery","nail","insulation","popcorn","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","door","pencil-eraser","staple","ice-skates","cricket-bat","chess-set","ukulele","cello","drumstick","pinball-machine","kitchen-sponge","roof-shingle","double-glazed-window","sailboat","dress-shirt","suit","handbag","wallet","flip-flops","hiking-boots","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","leather-shoe","tin-can","electric-guitar","trumpet","chopsticks","saxophone","felt-hat","vinyl-record","baseball-bat","smartphone","hard-drive","solid-state-drive","airbag","rocket","elevator","treadmill","air-conditioner","concrete","skyscraper","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","ink","photoresist","plastic-wrap","garden-hose","football","inflatable-pool-toy","chain-link-fence","pvc-pipe","power-cable","padlock","fireworks","cake-mix","hair-dye","soap","toothpaste","detergent","plastic-bag","nitrile-glove","paperclip","donut","corn-flakes","cotton-candy","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","cough-syrup","facial-tissue","condensed-milk","baby-formula","coconut-milk","canned-soup","paper-cup","candy-coated-chocolate","floor-tile","flag","newspaper","banknote","t-shirt","microchip","memory-chip","indium-tin-oxide","candy-cane","toffee","oled-screen"],"steps":[{"name":"Crack naphtha with steam","process":"react","text":"In the steam cracker that makes ethylene, naphtha is heated for milliseconds and a stream of propylene comes out beside it. Heavier feeds give more propylene, and ethane gives almost none.","inputs":["naphtha"]},{"name":"Crack heavy oil with a catalyst","process":"react","text":"In the refinery's fluid catalytic cracker, hot powdered catalyst meets vaporized heavy oil and breaks it into lighter molecules. The light gases include propylene, which refiners can collect or burn.","inputs":["crude-oil"]},{"name":"Quench and compress the gas","process":"chill","text":"The gas leaving the cracker is cooled and compressed, with heavy liquids and water removed first. A compressed gas is easier to separate.","inputs":[]},{"name":"Distill it away from ethylene","process":"refine","text":"Propylene is separated from propane and ethylene in tall cold columns. Propylene and propane boil at nearly the same temperature, so these columns are among the tallest in a refinery.","inputs":[]},{"name":"Store as a pressurized liquid","process":"fill","text":"Purified propylene is liquefied under pressure and stored in spherical tanks. Polypropylene plants nearby take most of it.","inputs":[]}],"facts":["Where propane is cheap, as in North America, plants also make propylene on purpose by stripping hydrogen from propane.","Fluid catalytic cracking units were running at 400 refineries worldwide as of 2006, so refineries are a big second source of propylene."],"where":[],"whereNote":null,"sources":[{"title":"Propylene","url":"https://en.wikipedia.org/wiki/Propylene"},{"title":"Steam cracking","url":"https://en.wikipedia.org/wiki/Steam_cracking"},{"title":"Fluid catalytic cracking","url":"https://en.wikipedia.org/wiki/Fluid_catalytic_cracking"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"prosecco","name":"Prosecco","kind":"product","category":"drink","title":"How prosecco is made","url":"https://assemblyline.org/make/prosecco","stations":5,"upstream":24,"downstream":0,"depth":6,"dek":"The bubbles are made in huge steel tanks instead of in each bottle, which is why prosecco costs less than champagne.","answer":"Prosecco is an Italian sparkling wine made mostly from the glera grape. After a first fermentation makes a still base wine, the wine goes into a sealed stainless steel pressure tank with sugar and yeast for a second fermentation. That Charmat method takes a minimum of 30 days and can run up to about nine months.","aka":["Italian sparkling wine","spumante"],"inputs":["grapes","yeast","sugar","glass-bottle"],"uses":[],"grounds":["grapes","water","sugarcane","sugar-beet","silica-sand","limestone","rock-salt","trona","natural-gas","air","corn","crude-oil"],"upstreamSlugs":["grapes","yeast","sugar","glass-bottle","water","molasses","sugarcane","sugar-beet","lime","silica-sand","soda-ash","limestone","polyethylene","rock-salt","ammonia","carbon-dioxide","trona","ethylene","natural-gas","air","corn","naphtha","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Pick the glera grapes","process":"harvest","text":"Prosecco grows across nine provinces in the Veneto and Friuli-Venezia Giulia regions. Up to 15 percent of the wine can come from other permitted varieties.","inputs":["grapes"]},{"name":"Ferment a still base wine","process":"ferment","text":"Pressed juice is fermented into an ordinary dry white wine with no bubbles.","inputs":["yeast"]},{"name":"Seal it in a pressure tank","process":"ferment","text":"The base wine is mixed with sugar and yeast in a stainless steel pressure tank. The second fermentation traps its carbon dioxide inside the tank, so the wine turns sparkling.","inputs":["sugar","yeast"],"spec":"30 days to about 9 months"},{"name":"Chill and filter","process":"separate","text":"Once the pressure is right the wine is chilled and filtered clear of yeast, still under pressure.","inputs":[]},{"name":"Bottle under pressure","process":"fill","text":"The sparkling wine is filled into thick glass bottles and closed. Most is spumante, fully sparkling, and some is frizzante, lightly sparkling.","inputs":["glass-bottle"]}],"facts":["The grape was called Prosecco until Italy renamed it Glera in 2009, and the wine takes its name from a village near Trieste.","The Charmat tank method was patented in 1895 by Federico Martinotti and improved by Eugène Charmat in 1907.","In 2019 the Prosecco hills of Conegliano and Valdobbiadene became a UNESCO World Heritage Site."],"where":[],"whereNote":null,"sources":[{"title":"Prosecco","url":"https://en.wikipedia.org/wiki/Prosecco"},{"title":"Sparkling wine production","url":"https://en.wikipedia.org/wiki/Sparkling_wine_production"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"prosthetic-leg","name":"Prosthetic leg","kind":"product","category":"body-health","title":"How prosthetic legs are made","url":"https://assemblyline.org/make/prosthetic-leg","stations":6,"upstream":45,"downstream":0,"depth":7,"dek":"Every socket is made on a copy of one person's leg, so no two are the same.","answer":"A prosthetic leg is made around a custom socket. A prosthetist captures the shape of the residual limb with a plaster cast or a 3D scan, modifies the model to relieve pressure points, and forms a socket over it from thermoplastic or carbon fiber and epoxy resin. The socket is then joined to a knee, a pylon and a foot.","aka":["artificial leg","prosthetic limb","prosthesis"],"inputs":["plaster","plastic","carbon-fiber","epoxy","polypropylene","silicone","titanium","aluminum"],"uses":[],"grounds":["gypsum","natural-gas","air","water","silica-sand","titanium-ore","crude-oil","coal","rock-salt","quartz","timber","dolomite","bauxite","sulfur","limestone"],"upstreamSlugs":["plaster","plastic","carbon-fiber","epoxy","polypropylene","silicone","titanium","aluminum","gypsum","naphtha","natural-gas","ethylene","propylene","ammonia","air","phenol","acetone","chlorine","caustic-soda","silicon","methanol","hydrochloric-acid","water","silica-sand","titanium-ore","magnesium","argon","crude-oil","coal","petroleum-coke","alumina","hydrogen","benzene","rock-salt","sulfuric-acid","quartz","coke","charcoal","timber","dolomite","bauxite","lime","toluene","sulfur","limestone"],"downstreamSlugs":[],"steps":[{"name":"Capture the limb shape","process":"mold","text":"A prosthetist casts the residual limb, sometimes using an air pressure system, or scans it digitally. Soft tissue changes shape under pressure, which makes this one of the hardest parts of the job.","inputs":["plaster"]},{"name":"Rectify the model","process":"machine","text":"Plaster is added to the model over areas that will need relief from pressure and removed where the limb can bear load. This can be done by hand or in software.","inputs":[]},{"name":"Try a diagnostic socket","process":"mold","text":"A test socket is formed over the model from transparent, heat-malleable plastic. It is not meant for permanent use, and it lets the prosthetist see whether the shape fits comfortably.","inputs":["plastic"]},{"name":"Form the final socket","process":"laminate","text":"The approved shape is wrapped with a heated sheet of thermoplastic or with carbon fiber coated in epoxy resin. Computerized models can also be 3D printed.","inputs":["carbon-fiber","epoxy","polypropylene"]},{"name":"Attach liner, knee and foot","process":"assemble","text":"A silicone liner fits between limb and socket and is held by suction or a pin lock. The socket is joined to a pylon, and a knee joint and foot, in lightweight metals and composites.","inputs":["silicone","titanium","aluminum"]},{"name":"Align and fit","process":"inspect","text":"The parts are aligned with the wearer standing, a step called static alignment, then adjusted as the wearer walks. A rehabilitation team then works with the user.","inputs":[]}],"facts":["A person with a leg missing above the knee uses roughly 80 percent more energy to walk.","The first commercially available microprocessor-controlled knee, the Intelligent Prosthesis, was released in 1993.","The first aluminum prosthesis was made by Marcel and Charles Desoutter."],"where":[],"whereNote":null,"sources":[{"title":"Prosthesis","url":"https://en.wikipedia.org/wiki/Prosthesis"},{"title":"Carbon fiber reinforced polymer","url":"https://en.wikipedia.org/wiki/Carbon_fiber_reinforced_polymer"},{"title":"How are Prosthetic Legs Made? (Össur)","url":"https://www.ossur.com/en-au/prosthetics/information/how-are-prosthetic-legs-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ptfe","name":"PTFE","kind":"material","category":"plastics","title":"How PTFE is made","url":"https://assemblyline.org/make/ptfe","stations":5,"upstream":8,"downstream":3,"depth":3,"dek":"PTFE was found by accident in 1938, when a cylinder of refrigerant gas turned into slippery white powder.","answer":"PTFE is made from tetrafluoroethylene gas, which a chemical plant produces from fluorspar, sulfuric acid and a chlorine-containing intermediate. The gas is polymerized in water under pressure into a slippery white powder or dispersion. It can be dried, ground, or compressed and heated into solid shapes, because it does not melt into a flowing liquid.","aka":["Teflon","polytetrafluoroethylene"],"inputs":["sulfuric-acid","fluorspar","natural-gas","chlorine","water"],"uses":["razor-blade","nonstick-pan","raincoat"],"grounds":["fluorspar","natural-gas","water","sulfur","air","rock-salt"],"upstreamSlugs":["sulfuric-acid","fluorspar","natural-gas","chlorine","water","sulfur","air","rock-salt"],"downstreamSlugs":["razor-blade","nonstick-pan","raincoat"],"steps":[{"name":"Make hydrofluoric acid","process":"react","text":"Fluorspar, the mineral calcium fluoride, is treated with sulfuric acid to give hydrofluoric acid. It is handled in specialist plants because it is dangerous.","inputs":["sulfuric-acid","fluorspar"]},{"name":"Make the fluorocarbon gas","process":"react","text":"Hydrofluoric acid reacts with chloroform, which is made from natural gas and chlorine. Heating the product forms tetrafluoroethylene.","inputs":["natural-gas","chlorine"]},{"name":"Polymerize it in water","process":"react","text":"The gas is pumped into a stirred reactor of water, where an initiator makes the molecules link into a chain of carbon wrapped in fluorine. The result is a powder or a milky dispersion.","inputs":["water"]},{"name":"Wash, dry and mill the resin","process":"dry","text":"Solids are washed, dried and ground to the grain size the buyer wants. Fine powder goes into coatings and coarse powder is pressed into blocks.","inputs":[]},{"name":"Press and sinter the shapes","process":"mold","text":"PTFE does not flow when it melts, so molders press the powder cold into a block and then bake it so the grains fuse. The block is machined into seals or skived into tape.","inputs":[]}],"facts":["Roy J. Plunkett found PTFE on 6 April 1938 when a cylinder of tetrafluoroethylene gas turned out to contain a white powder.","PTFE is a carbon chain surrounded entirely by fluorine, and it is heat resistant and chemically inert.","DuPont used PFOA for decades during PTFE production and later stopped after legal actions over health effects."],"where":[],"whereNote":null,"sources":[{"title":"Polytetrafluoroethylene","url":"https://en.wikipedia.org/wiki/Polytetrafluoroethylene"},{"title":"Polymerization","url":"https://en.wikipedia.org/wiki/Polymerization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pvc","name":"PVC","kind":"material","category":"plastics","title":"How PVC is made","url":"https://assemblyline.org/make/pvc","stations":6,"upstream":21,"downstream":22,"depth":5,"dek":"PVC is more than half chlorine by weight, which is why it starts with salt as well as oil.","answer":"PVC is made from vinyl chloride, which comes from ethylene and chlorine. The gas is stirred into water as tiny droplets and polymerized into a white powder, which is stripped of leftover monomer and dried. The powder is then blended with stabilizers and, for soft products, plasticizers, then extruded or pelletized.","aka":["polyvinyl chloride","vinyl"],"inputs":["ethylene","chlorine","water","pigment","plasticizer"],"uses":["credit-card","plastic-wrap","dishwasher","garden-hose","football","volleyball","yoga-mat","action-figure","fashion-doll","globe","inflatable-pool-toy","chain-link-fence","pvc-pipe","vinyl-floor","power-cable","smoke-detector","flip-flops","usb-cable","vinyl-record"],"grounds":["water","natural-gas","rock-salt","iron-ore","sulfur","air","crude-oil","titanium-ore","coal"],"upstreamSlugs":["ethylene","chlorine","water","pigment","plasticizer","naphtha","natural-gas","rock-salt","sulfuric-acid","iron-ore","titanium-dioxide","carbon-black","sulfur","air","propylene","crude-oil","hydrogen","titanium-ore","coke","oxygen","coal"],"downstreamSlugs":["credit-card","plastic-wrap","dishwasher","garden-hose","football","volleyball","yoga-mat","action-figure","fashion-doll","globe","inflatable-pool-toy","chain-link-fence","pvc-pipe","vinyl-floor","power-cable","smoke-detector","flip-flops","usb-cable","vinyl-record","aa-battery","popcorn","candy-cane"],"steps":[{"name":"Combine ethylene with chlorine","process":"react","text":"Ethylene and chlorine react to form ethylene dichloride, a liquid that is the main stepping stone to PVC. Plants also recycle hydrogen chloride from later steps back into this stage.","inputs":["ethylene","chlorine"]},{"name":"Crack it into vinyl chloride","process":"react","text":"Ethylene dichloride is heated in a furnace, which splits off hydrogen chloride and leaves vinyl chloride gas. The two are separated by distillation and the acid is sent back for reuse.","inputs":[]},{"name":"Polymerize it in water","process":"react","text":"In a large stirred reactor, vinyl chloride is dispersed in water as fine droplets with an initiator. Each droplet hardens into a tiny grain of polymer.","inputs":["water"]},{"name":"Strip and dry the powder","process":"dry","text":"Steam strips the unreacted vinyl chloride out of the slurry and it is recycled. The grains are spun out of the water and dried into a free-flowing white powder.","inputs":[]},{"name":"Compound with additives","process":"mix","text":"Raw PVC is a brittle white solid. Mixers add heat stabilizers, pigments and, for flexible products like cable insulation, plasticizers that make the plastic soft.","inputs":["pigment","plasticizer"]},{"name":"Extrude pipe or pellets","process":"extrude","text":"An extruder melts the compound and pushes it through a die to form pipe, window profiles or pellets. Pellets go to other factories for molding or calendering into film.","inputs":[]}],"facts":["PVC is the third most widely produced synthetic polymer, after polyethylene and polypropylene, with about 40 million tons made each year.","Eugen Baumann found PVC in 1872 as a white solid inside a flask of vinyl chloride that had sat on a shelf away from sunlight for four weeks.","Waldo Semon and the B.F. Goodrich Company developed a way to soften PVC with additives in 1926."],"where":[],"whereNote":null,"sources":[{"title":"Polyvinyl chloride","url":"https://en.wikipedia.org/wiki/Polyvinyl_chloride"},{"title":"Vinyl chloride","url":"https://en.wikipedia.org/wiki/Vinyl_chloride"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pvc-pipe","name":"PVC pipe","kind":"product","category":"plastics","title":"How PVC pipe is made","url":"https://assemblyline.org/make/pvc-pipe","stations":5,"upstream":22,"downstream":0,"depth":6,"dek":"PVC is the world's third most widely produced plastic, and pipe is one of its biggest jobs.","answer":"PVC pipe is extruded. White PVC resin powder is blended with stabilizers and other additives, melted in a screw extruder, and pushed through a ring-shaped die. The soft tube is cooled in water, hauled along at a steady speed, cut to length, and one end is flared into a socket.","aka":["plastic pipe","polyvinyl chloride pipe"],"inputs":["pvc","titanium-dioxide"],"uses":[],"grounds":["water","titanium-ore","natural-gas","rock-salt","iron-ore","sulfur","air","coal","crude-oil"],"upstreamSlugs":["pvc","titanium-dioxide","ethylene","chlorine","water","pigment","plasticizer","titanium-ore","coke","oxygen","sulfuric-acid","naphtha","natural-gas","rock-salt","iron-ore","carbon-black","sulfur","air","propylene","coal","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Blend the compound","process":"mix","text":"PVC powder is mixed with a heat stabilizer, white titanium dioxide pigment and other additives. Pipe for pressure or underground use has no plasticizer, so the plastic stays rigid.","inputs":["pvc","titanium-dioxide"]},{"name":"Melt it in the barrel","process":"melt","text":"A rotating screw drags the powder along a heated barrel, where it melts into a thick paste. PVC is more heat-sensitive than other common plastics, so the temperature is watched closely.","inputs":[]},{"name":"Extrude through the die","process":"extrude","text":"The melt is pushed through a ring-shaped opening around a central core, which forms a hollow tube of continuous length.","inputs":[]},{"name":"Cool in water","process":"chill","text":"The soft tube passes through water tanks that set its shape.","inputs":[]},{"name":"Cut and flare","process":"cut","text":"A saw cuts the tube to length, and one end is heated and flared into a socket that the next pipe fits into.","inputs":[]}],"facts":["PVC is the world's third most widely produced synthetic polymer, after polyethylene and polypropylene.","German chemist Eugen Baumann first synthesized the plastic in 1872.","Near 250 °C it starts to degrade, while polyethylene is stable to 400 °C."],"where":[],"whereNote":null,"sources":[{"title":"Polyvinyl chloride","url":"https://en.wikipedia.org/wiki/Polyvinyl_chloride"},{"title":"Extrusion","url":"https://en.wikipedia.org/wiki/Extrusion"},{"title":"Pipe (fluid conveyance)","url":"https://en.wikipedia.org/wiki/Pipe_(fluid_conveyance)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"quartz","name":"Quartz","kind":"raw","category":"ground","title":"How quartz is mined","url":"https://assemblyline.org/make/quartz","stations":5,"upstream":0,"downstream":196,"depth":0,"dek":"One North Carolina district supplies most of the world's high-purity quartz, the raw stuff of silicon-chip crucibles.","answer":"The purest quartz starts as pegmatite rock, dug at places like Spruce Pine in North Carolina alongside feldspar and mica. Crushing and grinding free the grains, though the rock is abrasive enough to contaminate itself with iron from the mills. Flotation and magnets remove other minerals, then strong acid and hot chlorine gas chase out the last traces of aluminum, iron and sodium.","aka":["rock crystal","silica"],"inputs":[],"uses":["silicon","silicon-wafer","ceramic","porcelain"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["silicon","silicon-wafer","ceramic","porcelain","silicone","polysilicon","magnesium","trichlorosilane","microchip","memory-chip","camera-sensor","solar-cell","inkjet-printer","hip-implant","faucet","turbine-blade","snow-globe","shampoo","deodorant","syringe","condom","hearing-aid","solar-panel","contact-lens","airbag","cork-stopper","pressure-cooker","blender","foundation-makeup","eyeshadow","prosthetic-leg","double-glazed-window","remote-control","electric-toothbrush","steel","titanium","water-heater","toy-car","digital-camera","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","rocket","smartwatch","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","e-reader","graphics-card","jet-engine","car","champagne","aluminum-window-frame","toothbrush","lithium-ion-cell","ev-battery","aa-battery","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","loudspeaker","refrigerator","microwave-oven","washing-machine","air-conditioner","treadmill","safety-pin","ceiling-fan","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","concrete","skyscraper","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sailboat","action-figure","power-outlet","electric-kettle","pencil","mirror","golf-ball","wallpaper","wooden-chair","water-bottle","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","neon-sign","toffee"],"steps":[{"name":"Dig the pegmatite","process":"mine","text":"Spruce Pine pegmatite holds quartz mixed with plagioclase, microcline and muscovite, and the district is mined for all of them. Quartz from this rock formed with few inclusions, which is why it suits high-purity work.","inputs":[]},{"name":"Crush, scrub and grind","process":"crush","text":"Ore passes through a primary crusher and a scrubber, then a mill. One North Carolina evaluation ground it to 60 by 140 mesh. Quartz is so hard and abrasive that ordinary grinding gear sheds iron into the product, so specialist equipment is used.","inputs":[]},{"name":"Float off other minerals","process":"separate","text":"Flotation lifts away mica, iron minerals and feldspar. Magnetic separators then clean the remaining quartz, and the product is sized.","inputs":[]},{"name":"Leach with strong acid","process":"refine","text":"A leach in strong acid cuts iron and magnesium sharply. In one North Carolina test, aluminum, calcium, sodium and potassium stayed too high after leaching, so those elements decide the final grade.","inputs":[]},{"name":"Chlorinate at high heat","process":"refine","text":"The typical flow sheet ends in a hot chlorine atmosphere that pulls out further impurities. The gas risk is serious enough that only specialist companies run this stage. Finished quartz sand goes to makers of crucibles for chips and solar cells.","inputs":[]}],"facts":["On the Mohs hardness scale, quartz sets the value of 7.","In the 17th century Nicolas Steno found that the angles between a quartz crystal's long faces stay the same, whatever its size.","Analysts call Spruce Pine a single point of failure for the chip industry, because roughly 70 to 90% of all high-purity quartz comes from there."],"where":[],"whereNote":null,"sources":[{"title":"The challenges of producing high purity quartz","url":"https://ausimm.com/publications/conference-proceedings/international-future-mining-conference-2024-proceedings/the-challenges-of-producing-high-purity-quartz"},{"title":"Evaluation of quartz resources, North Carolina (GSA abstract)","url":"https://gsa.confex.com/gsa/2006SE/webprogram/Paper101760.html"},{"title":"High Purity Quartz","url":"https://www.thequartzcorp.com/high-purity-quartz"},{"title":"Spruce Pine Mining District","url":"https://en.wikipedia.org/wiki/Spruce_Pine_Mining_District"},{"title":"Quartz","url":"https://en.wikipedia.org/wiki/Quartz"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"lime","name":"Quicklime","kind":"material","category":"chemicals","title":"How quicklime is made","url":"https://assemblyline.org/make/lime","stations":6,"upstream":2,"downstream":403,"depth":1,"dek":"Quicklime is limestone with the carbon dioxide cooked out of it, and it will grab that gas back from the air.","answer":"Quicklime is made by heating crushed limestone in a kiln until it gives off carbon dioxide and leaves calcium oxide. The white lumps are cooled and either crushed for sale as they are or mixed with water to make slaked lime, a milder but still strongly alkaline powder or putty used in mortar, steelmaking and sugar refining.","aka":["burnt lime","calcium oxide","unslaked lime","slaked lime","hydrated lime"],"inputs":["limestone","water"],"uses":["soda-ash","steel","alumina","gold","silver","sugar","gelatin","tortilla","wood-pulp","leather"],"grounds":["limestone","water"],"upstreamSlugs":["limestone","water"],"downstreamSlugs":["soda-ash","steel","alumina","gold","silver","sugar","gelatin","tortilla","wood-pulp","leather","detergent","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","baking-soda","instant-noodles","stained-glass","vanadium","toothbrush","lithium-ion-cell","ev-battery","aa-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","inkjet-printer","electric-toothbrush","aluminum","laminate-floor","microchip","led","needle","gold-ring","fountain-pen","gold-bar","medal","smoke-detector","solar-cell","solder","coin","mirror","trumpet","thermos","flute","light-switch","vinyl-record","penicillin","insulin","vitamin-c","brown-sugar","yogurt","ice-cream","mayonnaise","ketchup","peanut-butter","croissant","donut","sandwich-cookie","corn-flakes","bacon","chocolate","gummy-bears","marshmallow","jelly-beans","candy-cane","chewing-gum","cotton-candy","sprinkles","cola","champagne","hard-cider","condensed-milk","pickles","kimchi","jam","hazelnut-spread","bagel","imitation-crab","salami","ham","beef-jerky","canned-meat","white-chocolate","caramel-color","candy-coated-chocolate","licorice","caramel","lollipop","toffee","popping-candy","gelatin-dessert","cake-mix","soda","root-beer","energy-drink","kombucha","tonic-water","prosecco","cough-syrup","wine","gelatin-capsule","banknote","nail-polish","kitchen-sponge","sanitary-pad","cellulose-acetate","paper","cardboard","toilet-paper","facial-tissue","rayon","diaper","baseball","basketball","tennis-racket","football","winter-gloves","handbag","wallet","hiking-boots","digital-camera","leather-shoe","printed-circuit-board","surfboard","kite","roof-shingle","vinyl-floor","canoe","sailboat","umbrella","hip-implant","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","stent","nichrome","thermometer","lcd-screen","oled-screen","camera-sensor","solar-panel","microwave-oven","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","floor-tile","neon-sign","smartwatch","e-reader","skyscraper","windshield","double-glazed-window","perfume","vaccine","sparkling-water","beer","whiskey","vodka","gin","rum","tequila","sake","hot-sauce","bourbon","scotch","cognac","mezcal","mead","port-wine","non-alcoholic-beer","smartphone","pretzel","frozen-pizza","crackers","fire-extinguisher","laptop","drone","satellite","wireless-earbuds","electric-car","refrigerator","washing-machine","blender","air-conditioner","treadmill","game-console","graphics-card","phone-charger","car","airbag","ceiling-fan","hinge","saw-blade","shovel","wheelbarrow","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","suspension-bridge-cable","mattress","concrete","roller-skates","deodorant","lipstick","led-bulb","solid-state-drive","pencil","aluminum-foil","brass","cobalt","nonstick-pan","aluminum-can","rocket","pencil-eraser","pressure-cooker","eyeshadow","asthma-inhaler","prosthetic-leg","ladder","aluminum-window-frame","microphone","camera-lens","compact-disc","newspaper","zipper","n95-mask","hearing-aid","pacemaker","credit-card","computer-keyboard","computer-mouse","wifi-router","remote-control","pinball-machine","flour","dice","shoelace","soap","adhesive-bandage","drywall","popcorn","crayon","fireworks","plastic-straw","paper-straw","paper-cup","paper-bag","pizza-box","egg-carton","wallpaper","board-game","jigsaw-puzzle","tampon","cotton-swab","book","envelope","sticky-notes","playing-cards","duct-tape","plastic-wrap","clear-tape","trading-cards","hair-dye","cardboard-box","match","syringe","electric-kettle","kitchen-knife","fork","water-bottle","jet-engine","mustard","salsa","sauerkraut","shampoo","dish-soap","foundation-makeup","paint","baby-formula","coconut-milk","canned-soup","action-figure","power-outlet","toothpaste","aspirin","condom","garden-hose","key","flag","tungsten-carbide","light-beer","insect-repellent","down-jacket","raincoat","backpack","jeans","bread","chicken-nuggets","baguette","sourdough","fish-sticks","modeling-clay","plastic-bag","nitrile-glove","candle","zip-bag","pillow","mouthwash","golf-ball","wooden-chair","billiard-ball","fashion-doll"],"steps":[{"name":"Quarry the limestone","process":"mine","text":"Rock is blasted out of a quarry or mine. Makers pick stone by its chemistry, because the clay and magnesium inside it change how the finished lime behaves.","inputs":["limestone"]},{"name":"Crush and screen the stone","process":"crush","text":"Crushers break the rock into fist-sized pieces and screens sort them by size. Pieces of similar size heat evenly, so a kiln loaded with them cooks the whole charge at the same rate.","inputs":[]},{"name":"Burn it in a kiln","process":"fire","text":"The stone sits in a tall shaft or a long rotating kiln until it is hot enough to break apart. Carbon dioxide leaves with the exhaust, so the lumps that come out weigh far less than the stone that went in.","inputs":[],"spec":"above 900 °C"},{"name":"Cool and draw off the lumps","process":"chill","text":"Air blown through the bottom of the kiln cools the lime and carries heat back up to the stone above. The white lumps are drawn out and screened again.","inputs":[]},{"name":"Slake it with water","process":"react","text":"For many uses the lime is mixed with water, which makes it hiss and give off heat as it turns into calcium hydroxide. A little water leaves a dry powder. An excess of water leaves a thick putty.","inputs":["water"]},{"name":"Mill and bag the powder","process":"grind","text":"Lumps are ground to a fine powder, sealed and shipped quickly, because the product slowly takes carbon dioxide and moisture back from the air.","inputs":[]}],"facts":["Lime turns back into limestone on its own: slaked lime in old mortar slowly absorbs carbon dioxide from the air and reverts to calcium carbonate.","Lime kilns date back to prehistoric times, and the earliest descriptions of them differ little from the small kilns that survived into the last century."],"where":[],"whereNote":null,"sources":[{"title":"Lime (material)","url":"https://en.wikipedia.org/wiki/Lime_%28material%29"},{"title":"Lime kiln","url":"https://en.wikipedia.org/wiki/Lime_kiln"},{"title":"Calcination","url":"https://en.wikipedia.org/wiki/Calcination"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rail","name":"Railroad rail","kind":"product","category":"metals","title":"How railroad rail is made","url":"https://assemblyline.org/make/rail","stations":9,"upstream":25,"downstream":0,"depth":5,"dek":"Rail is shaped like a lopsided I-beam, with a hardened head for wheels and a wide foot for the ties.","answer":"Rail starts as high-carbon steel vacuum-degassed to pull out the hydrogen that can later crack it. Continuous casting makes a bloom, which is reheated to around 1250 °C and rolled, pass by pass, into a head, web and foot. The head may be hardened, then the rail is cooled, roller-straightened, cut, marked and checked by ultrasound before track crews weld it into long strings.","aka":["railway rail","railroad track","steel rail","T-rail"],"inputs":["steel"],"uses":[],"grounds":["iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","coal","quartz","timber","crude-oil","sulfur"],"upstreamSlugs":["steel","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","coal","quartz","charcoal","timber","crude-oil","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Make very clean steel","process":"refine","text":"A basic oxygen or electric arc furnace makes high-carbon steel, then vacuum degassing removes dissolved hydrogen and oxygen. Hydrogen left in the metal can crack a rail months or years after it is laid.","inputs":["steel"]},{"name":"Cast the blooms","process":"cast","text":"Degassed steel is continuously cast into large rectangular blooms, typically around 280×380 mm.","inputs":[],"spec":"around 280×380 mm"},{"name":"Roll through shaped grooves","process":"roll","text":"From a reheating furnace, the bloom passes through roughing, intermediate and finishing mills with grooved rolls. A universal mill usually does the last passes, setting head, web and foot at once to within about ±0.5 mm.","inputs":[],"spec":"reheated to about 1250 °C"},{"name":"Harden the head","process":"heat-treat","text":"Spray quenching with the rail's own rolling heat, or later quenching and tempering in a separate facility, can harden the running surface to HB300 or more. The core stays tougher.","inputs":[]},{"name":"Control the cooling","process":"chill","text":"On the cooling bed, mills control how the rail lies, since the thick head and thinner foot shrink at different rates. Rushed cooling locks in stress that shows up as warping weeks or months after installation.","inputs":[]},{"name":"Straighten with rollers","process":"press","text":"A roller straightener works the rail from the horizontal and vertical directions. One patent describes massive rollers exerting 100 to 180 tons.","inputs":[]},{"name":"Cut and mark","process":"cut","text":"The rail is cut to ordered length, with 12m, 25m and 100m all common, and may be drilled for bolts. Grade, melt number and maker are rolled into the web or stamped on the end.","inputs":[]},{"name":"Inspect by ultrasound","process":"inspect","text":"Ultrasonic testing looks for inclusions, voids and cracks inside the head, web and foot. Eddy current testing catches surface flaws the eye would miss.","inputs":[]},{"name":"Weld into long strings","process":"weld","text":"Lengths are joined by welding, in a depot or in the field, which removes joints, the weakest part of a line. Welded track began around the 1940s and was widespread by the 1960s.","inputs":[]}],"facts":["Robert Forester Mushet made the first steel rails in 1857 and laid them at Derby station in England.","In rail steel, tensile strength rises with carbon content while ductility falls, so the carbon is held in a narrow range.","A worn, heavy rail from a main line often gets a second life on a quieter branch line or in a yard."],"where":[],"whereNote":null,"sources":[{"title":"Rail profile","url":"https://en.wikipedia.org/wiki/Rail_profile"},{"title":"Railway Rail Manufacturing Process, RailwayPart","url":"https://www.railwaypart.com/railway-knowledge-center/railway-rail-manufacturing-process/"},{"title":"US5195573A: Continuous rail production","url":"https://patents.google.com/patent/US5195573A/en"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"raincoat","name":"Raincoat","kind":"product","category":"textiles","title":"How raincoats are made","url":"https://assemblyline.org/make/raincoat","stations":7,"upstream":59,"downstream":0,"depth":9,"dek":"Stitching punches holes in a waterproof coat, so every seam then gets a strip of tape melted over it.","answer":"Modern raincoats are made from woven nylon or polyester fabric that is coated or laminated with a thin membrane. The pores are too small for raindrops but large enough for water vapor. Panels are cut, sewn, and the seams are sealed with tape so water cannot enter through the needle holes.","aka":["rain jacket","mackintosh","waterproof jacket","rain shell"],"inputs":["nylon","polyester","ptfe","polyurethane","adhesive","thread","zipper"],"uses":[],"grounds":["fluorspar","natural-gas","water","air","sulfur","rock-salt","crude-oil","coal","copper-ore","zinc-ore","lead-ore","tin-ore","bauxite","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["nylon","polyester","ptfe","polyurethane","adhesive","thread","zipper","benzene","nitric-acid","ammonia","pet-plastic","sulfuric-acid","fluorspar","natural-gas","chlorine","water","propylene","polyethylene","acrylic","epoxy","paraffin-wax","brass","aluminum","naphtha","hydrogen","toluene","air","p-xylene","ethylene","ethylene-glycol","sulfur","rock-salt","crude-oil","methanol","phenol","acetone","caustic-soda","copper","zinc","lead","tin","coal","petroleum-coke","alumina","oxygen","carbon-dioxide","copper-ore","zinc-ore","lead-ore","coke","tin-ore","bauxite","lime","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Weave the face fabric","process":"weave","text":"Nylon or polyester yarn is woven into a tough, tightly packed cloth. The weave is the first barrier water meets, and it supports the membrane behind it.","inputs":["nylon","polyester"]},{"name":"Laminate the membrane","process":"laminate","text":"A thin plastic film with microscopic pores, or a polyurethane coating, is bonded to the back of the fabric. The pores let vapor pass but are far too small for liquid droplets.","inputs":["ptfe","polyurethane","adhesive"]},{"name":"Spray the outer repellent","process":"coat","text":"A durable water-repellent finish is applied to the outer face so rain beads up and falls off instead of soaking in. Without it the face fabric wets out and the coat stops breathing.","inputs":[]},{"name":"Cut the panels","process":"cut","text":"Cutters cut the body, sleeve, hood and pocket pieces from the coated roll, taking care not to scratch the membrane.","inputs":[]},{"name":"Sew the seams","process":"sew","text":"Panels are stitched together, and the needle holes along the seams become tiny leak paths. Zips and drawcords are added at the front and hood.","inputs":["thread","zipper"]},{"name":"Tape every seam","process":"laminate","text":"A strip of thermoplastic tape is melted over each seam on the inside with heat and pressure. Gore-Tex garments are made only in certified factories, using the tape that Gore specifies.","inputs":["adhesive"]},{"name":"Test and pack","process":"inspect","text":"Factories test sample seams in water at intervals during production. Finished coats are then checked for loose threads, folded and packed.","inputs":[]}],"facts":["Waterproof fabric is rated in millimeters of water that can stand on it before any seeps through. Mid-range fabric typically has a rating of 5,000.","Garments made from fabrics that exceed 20,000 mm have still leaked through zips, hoods and seams in rain-room testing."],"where":[],"whereNote":null,"sources":[{"title":"Raincoat","url":"https://en.wikipedia.org/wiki/Raincoat"},{"title":"Waterproof fabric","url":"https://en.wikipedia.org/wiki/Waterproof_fabric"},{"title":"What are taped seams? (Advnture)","url":"https://www.advnture.com/features/what-are-taped-seams"},{"title":"A visit to the Maegaki factory (Outdoor Gear Zine)","url":"https://outdoorgearzine.com/en/column-special-company-maegaki-01"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rapeseed","name":"Rapeseed","kind":"raw","category":"farm","title":"How rapeseed is grown and harvested","url":"https://assemblyline.org/make/rapeseed","stations":5,"upstream":0,"downstream":162,"depth":0,"dek":"Canola is rapeseed that was bred to have low erucic acid, and the name was a trademark before it became a word.","answer":"Rapeseed goes in during autumn across most of Europe and Asia and sits through winter as a leaf rosette, while Canadian crops are sown in spring. Pods ripen over 6 to 8 weeks, bottom of the plant first. Many growers cut the crop into windrows at 30 to 60% seed color change, then combine it days later.","aka":["canola","oilseed rape","rapeseed farming","rapeseed crop"],"inputs":[],"uses":["vegetable-oil"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["vegetable-oil","soap","shampoo","deodorant","sunscreen","mascara","detergent","ink","glycerin","cast-iron-pan","margarine","mayonnaise","peanut-butter","tortilla","donut","sandwich-cookie","potato-chips","french-fries","canned-tuna","chicken-nuggets","baby-formula","oat-milk","crackers","fish-sticks","biodiesel","wooden-spoon","pencil-eraser","modeling-clay","cake-mix","foundation-makeup","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","toothpaste","chewing-gum","snow-globe","cough-syrup","gelatin-capsule","diesel","vacuum-cleaner","electric-kettle","cotton-candy","pillow","paint","condensed-milk","coconut-milk","canned-meat","canned-soup","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","car","electric-car","nitrile-glove","washing-machine","paperclip","corn-flakes","popcorn","crayon","fireworks","candle","salsa","zip-bag","blender","dishwasher","cotton-swab","mouthwash","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","locomotive","refrigerator","microwave-oven","pencil","scissors","mirror","airplane","container-ship","shipping-container","bicycle","motorcycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","toy-car","coil-spring","hammer","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","padlock"],"steps":[{"name":"Sow in autumn or spring","process":"grow","text":"Winter varieties go in during autumn and need the cold to flower. Spring types, grown in Canada, northern Europe and Australia, cannot survive winter and start stem growth right after germination. In Europe the winter crop often rotates with wheat and barley every three to four years, to limit pests and disease.","inputs":[]},{"name":"Flower and fill the pods","process":"grow","text":"Flowering starts at the lowest bud and works upward. Pods grow 5 to 10 cm long and ripen from green to brown over 6 to 8 weeks, each holding a row of hard black seeds 1.5 to 3 mm across.","inputs":[],"spec":"6 to 8 weeks of pod ripening"},{"name":"Check seed color","process":"inspect","text":"Growers open main-stem pods from around the field, since hilltops ripen ahead of low spots. At 35 to 40% moisture seeds turn from green to yellow or brown. The best time to cut is at 30 to 60% color change, and seed stops filling once the crop is down.","inputs":[]},{"name":"Cut into windrows","process":"harvest","text":"A swather lays the crop in rows on the stubble, which cuts shattering and can speed dry-down by up to 10 days. Draper-belt machines do less damage than augers, and some growers roll the swath so wind cannot shift it. Others skip this step and combine the standing crop directly.","inputs":[]},{"name":"Combine the dry swaths","process":"harvest","text":"Combining waits until seed drops below 10% moisture, normally 5 to 10 days after swathing. Rubber fingers lift the row gently. The cylinder turns at about 60 percent of cereal speed, and cleaning leans on shaking over wind, since the seed is light enough to blow out the back.","inputs":[],"spec":"under 10% seed moisture"}],"facts":["Canadian scientists launched a marketing campaign in 1973 for what became canola, trademarked in 1978 by the Canola Council of Canada.","World rapeseed production rose sixfold between 1975 and 2007.","The word rape comes from the Latin for turnip, rapa."],"where":[],"whereNote":null,"sources":[{"title":"Rapeseed","url":"https://en.wikipedia.org/wiki/Rapeseed"},{"title":"Canola","url":"https://en.wikipedia.org/wiki/Canola"},{"title":"Canola Harvest Management, Alberta Agriculture and Forestry","url":"https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/inf1299"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rare-earth-ore","name":"Rare earth ore","kind":"raw","category":"ground","title":"How rare earth ore is mined","url":"https://assemblyline.org/make/rare-earth-ore","stations":4,"upstream":0,"downstream":7,"depth":0,"dek":"Rare earths are scattered so thinly through the crust that very few places hold enough to mine.","answer":"The 17 rare-earth elements reach industry by two very different routes. Hard ores such as bastnäsite come from open pits like Mountain Pass in California, where crushed rock is ball-milled and floated into a concentrate. Heavy rare earths mostly come from clays, where they cling to particle surfaces and are rinsed out with a salt solution, often right in the ground.","aka":["REE ore","bastnäsite","monazite"],"inputs":[],"uses":["neodymium-magnet"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["neodymium-magnet","headphones","wind-turbine","wireless-earbuds","loudspeaker","microphone","electric-toothbrush"],"steps":[{"name":"Dig the open pit","process":"mine","text":"At Mountain Pass in California the main mineral of value is bastnäsite. It is dug from an open pit and hauled to a primary crushing and stockpile area.","inputs":[]},{"name":"Ball-mill to slurry","process":"grind","text":"Crushed ore joins recycled water in a ball mill that runs in closed circuit with cyclones. Fine slurry is pumped on to conditioning and flotation equipment.","inputs":[]},{"name":"Float the bastnäsite","process":"separate","text":"Flotation parts the bastnäsite from barite, calcite and dolomite. The concentrate is thickened and filtered, then sold or sent to a separations plant, where the near-identical elements are pulled apart.","inputs":[]},{"name":"Rinse the clays","process":"wash","text":"In ion-adsorption clays the elements sit on particle surfaces, so a sulfate or chloride salt solution can swap them out at ambient temperature. Most recovery has been done in place in the ground. One patent notes that this route tends to pollute groundwater, and leaching in a reactor is proposed instead.","inputs":[]}],"facts":["Rare earths are often found with thorium and sometimes uranium, so mining them can bring radioactive waste.","In 1787 a strange black mineral from a quarry at Ytterby, Sweden, led to the discovery of the first rare earths, and several elements are named after that village.","China raised its share of rare-earth production from 21% to 60% between 1985 and 1995."],"where":[{"place":"China","share":"about 90% of global demand supplied"}],"whereNote":"China's supply in 2019, as a share of demand for the powders.","sources":[{"title":"MP Materials Technical Report Summary, Mountain Pass","url":"https://www.sec.gov/Archives/edgar/data/1801368/000180136825000009/mpmcexhibit961123124.htm"},{"title":"Recovering rare earth elements from ion adsorption clays (patent WO2016128621)","url":"https://patents.google.com/patent/WO2016128621"},{"title":"Mountain Pass Rare Earth Mine","url":"https://en.wikipedia.org/wiki/Mountain_Pass_Rare_Earth_Mine"},{"title":"Rare-earth element","url":"https://en.wikipedia.org/wiki/Rare-earth_element"},{"title":"Bastnäsite","url":"https://en.wikipedia.org/wiki/Bastn%C3%A4site"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"raw-cotton","name":"Raw cotton","kind":"raw","category":"farm","title":"How cotton is grown and harvested","url":"https://assemblyline.org/make/raw-cotton","stations":3,"upstream":0,"downstream":27,"depth":0,"dek":"Cotton is almost pure cellulose, and one machine invention in 1793 made it cheap enough to clothe the world.","answer":"Cotton is a shrub grown in long frost-free seasons with plenty of sun. The fiber grows inside a protective case called a boll, around the seeds. When the bolls open, a picker machine lifts the fiber out, or a stripper tears the whole boll off the plant after a defoliant or a freeze has dropped the leaves.","aka":["cotton bolls","seed cotton","cotton crop","cotton farming"],"inputs":[],"uses":["nail-polish","tampon","cotton-swab","banknote","cotton-yarn"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["nail-polish","tampon","cotton-swab","banknote","cotton-yarn","tennis-ball","candle","hoodie","dress-shirt","underwear","shoelace","curtain","cotton-fabric","denim","t-shirt","socks","towel","adhesive-bandage","duct-tape","sofa","pillow","handbag","rubber-boots","book","sneaker","baseball-cap","jeans"],"steps":[{"name":"Plant in a frost-free field","process":"grow","text":"Cotton needs a long stretch without frost, lots of sunshine and moderate rainfall, usually 50 to 100 cm a year. Heavy soils suit it, and much of today's crop is irrigated in drier regions. Bt varieties carry a bacterial gene that kills bollworms.","inputs":[],"spec":"50 to 100 cm of rain"},{"name":"Drop the leaves","process":"dry","text":"In the tropics cotton is a perennial and keeps growing. Farmers spray a chemical defoliant, or wait for a freeze, so the leaves fall and the bolls can be taken cleanly.","inputs":[]},{"name":"Pick or strip the bolls","process":"harvest","text":"A cotton picker removes the fiber from each boll without harming the plant. A stripper pulls the entire boll off, and is used where wind makes picker varieties hard to grow. In some developing countries the crop is still picked by hand.","inputs":[]}],"facts":["Hand-roller gins were already used in India in the 6th century, long before Eli Whitney's 1793 machine.","In January 2019 a cotton seed sprouted on the far side of the Moon inside China's Chang'e 4 lander.","Before the cotton gin, producing one bale of cotton took over 600 hours of human labor."],"where":[{"place":"China","share":"26% of world output"},{"place":"India","share":"22%"},{"place":"United States","share":"12%"}],"whereNote":"2022, share of world cotton production by weight.","sources":[{"title":"Cotton","url":"https://en.wikipedia.org/wiki/Cotton"},{"title":"Cotton picker","url":"https://en.wikipedia.org/wiki/Cotton_picker"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"raw-milk","name":"Raw milk","kind":"raw","category":"farm","title":"How milk is produced on a dairy farm","url":"https://assemblyline.org/make/raw-milk","stations":3,"upstream":0,"downstream":22,"depth":0,"dek":"Left to stand, fresh milk separates on its own, as the fat floats up into a cream layer within 12 to 24 hours.","answer":"Milk comes from cows kept on dairy farms, and cows have been bred to give far more than a calf needs. Most are milked twice a day, by machine in developed countries. The milk is cooled on the farm and collected for a dairy plant. About 85% of the world's milk comes from cows.","aka":["cow's milk","dairy farming","fresh milk","milking","farm milk"],"inputs":[],"uses":["butter","pasteurized-milk","cream-cheese","parmesan","sour-cream","powdered-milk","condensed-milk","baby-formula","cream"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["butter","pasteurized-milk","cream-cheese","parmesan","sour-cream","powdered-milk","condensed-milk","baby-formula","cream","croissant","caramel","toffee","cheese","yogurt","ice-cream","mozzarella","cheddar","chocolate","hazelnut-spread","white-chocolate","frozen-pizza","candy-coated-chocolate"],"steps":[{"name":"Breed the dairy herd","process":"grow","text":"A cow must calve before she gives milk, and the gestation period is about nine months. Dairy breeds such as the Holstein have been bred selectively for higher milk production, and farms often use artificial insemination.","inputs":[]},{"name":"Milk twice a day","process":"harvest","text":"Most cows are milked twice per day. Hand milking in barns gave way to vacuum bucket milkers in the early twentieth century and then to pipeline and automated milking equipment, which now produces the vast majority of milk in developed countries.","inputs":[]},{"name":"Ship it to the dairy","process":"harvest","text":"Milk is processed at a dairy, either onsite at the farm or after being shipped. Untreated milk separates on its own over 12 to 24 hours into a fatty cream layer and a larger, low-fat layer, which centrifugal separators now do quickly.","inputs":[]}],"facts":["Pigs are almost never milked, because a sow has many small teats and cannot store her milk the way a cow can.","Dairy farms produced around 730 million tonnes of milk from 260 million dairy cows in 2011.","Water buffalo, goats, sheep and camels also supply milk, with buffalo providing about 11% of the world total in 2011."],"where":[{"place":"India","share":"largest producer of milk and milk products"},{"place":"United States","share":"second largest"},{"place":"China","share":"third largest"},{"place":"Pakistan","share":"fourth largest"},{"place":"Brazil","share":"fifth largest"}],"whereNote":"2012, ranking of milk and milk products output by country.","sources":[{"title":"Milk","url":"https://en.wikipedia.org/wiki/Milk"},{"title":"Dairy farming","url":"https://en.wikipedia.org/wiki/Dairy_farming"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rayon","name":"Rayon","kind":"material","category":"textiles","title":"How rayon is made","url":"https://assemblyline.org/make/rayon","stations":6,"upstream":14,"downstream":1,"depth":4,"dek":"Rayon is wood dissolved into a syrup, squirted through tiny holes into an acid bath, and turned back into fiber.","answer":"Rayon is regenerated cellulose. Wood pulp is soaked in caustic soda, pressed and shredded, then treated with carbon disulfide so it dissolves into a thick golden syrup called viscose. After ripening, the syrup is forced through the tiny holes of a spinneret into a sulfuric acid bath, where it hardens into filaments.","aka":["viscose","artificial silk","regenerated cellulose"],"inputs":["wood-pulp","caustic-soda","sulfuric-acid","water"],"uses":["tampon"],"grounds":["water","timber","rock-salt","sulfur","air","limestone","natural-gas"],"upstreamSlugs":["wood-pulp","caustic-soda","sulfuric-acid","water","timber","lime","oxygen","hydrogen-peroxide","rock-salt","sulfur","air","limestone","hydrogen","natural-gas"],"downstreamSlugs":["tampon"],"steps":[{"name":"Soak the pulp in lye","process":"react","text":"Sheets of wood pulp, mostly pure cellulose, are soaked in strong caustic soda. The treated sheets are pressed between rollers to squeeze out the extra liquid.","inputs":["wood-pulp","caustic-soda"]},{"name":"Shred and age the crumb","process":"crush","text":"The pressed sheets are shredded into a fluffy white crumb. The crumb sits for a time so the long cellulose chains shorten to the right length.","inputs":[]},{"name":"Turn it into xanthate","process":"react","text":"The white crumb is mixed in vats with carbon disulfide. This turns it into an orange-yellow crumb that can dissolve.","inputs":[]},{"name":"Dissolve and ripen","process":"mix","text":"The crumb is dissolved in a caustic solution to form viscose, a thick, honey-like liquid. The liquid is left to ripen while its molecular weight changes, then filtered and degassed.","inputs":["caustic-soda"]},{"name":"Squirt into an acid bath","process":"extrude","text":"Viscose is pumped through a spinneret, a plate with tiny holes, into a bath of sulfuric acid. The acid turns the liquid back into solid cellulose filaments in a moment.","inputs":["sulfuric-acid"]},{"name":"Wash, desulfur and cut","process":"wash","text":"The new filaments are washed to remove acid, treated to remove sulfur and bleached. They are then wound as continuous filament or cut into short staple lengths.","inputs":["water"]}],"facts":["Charles Cross and his colleagues patented viscose in 1894 and named it for the highly viscous solution made along the way.","The first commercial viscose rayon was produced by Courtaulds in the UK in November 1905.","The Lyocell process makes the same kind of fiber without neurotoxic carbon disulfide, but costs more."],"where":[],"whereNote":null,"sources":[{"title":"Rayon","url":"https://en.wikipedia.org/wiki/Rayon"},{"title":"Pulp (paper)","url":"https://en.wikipedia.org/wiki/Pulp_(paper)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"razor-blade","name":"Razor blade","kind":"product","category":"hardware","title":"How razor blades are made","url":"https://assemblyline.org/make/razor-blade","stations":6,"upstream":37,"downstream":0,"depth":7,"dek":"The first reusable stainless steel blades arrived in 1960, from a Sheffield maker of ceremonial swords.","answer":"A razor blade is a thin ribbon of hardened steel. Stainless strip runs through a hardening furnace and a quench, then is ground to a wedge along its edge. A strengthening metal layer is sputtered on and a slippery fluoropolymer is sintered over it. The ribbon is then cut into individual blades and mounted in cartridges.","aka":["safety razor blade","shaving blade"],"inputs":["stainless-steel","chromium","ptfe"],"uses":[],"grounds":["chromite","limestone","air","water","fluorspar","natural-gas","nickel-ore","coal","rock-salt","trona","crude-oil","sulfur","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["stainless-steel","chromium","ptfe","steel-scrap","nickel","oxygen","argon","chromite","coke","soda-ash","limestone","air","water","aluminum","sulfuric-acid","fluorspar","natural-gas","chlorine","propane","nickel-ore","coal","rock-salt","ammonia","carbon-dioxide","lime","trona","crude-oil","petroleum-coke","alumina","sulfur","corn","yeast","bauxite","caustic-soda","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Roll the ribbon","process":"roll","text":"Stainless steel is rolled into a very thin strip, then slit to the width of a blade.","inputs":["stainless-steel"]},{"name":"Punch the holes","process":"stamp","text":"A die punches the slots and notches that will later hold each blade in its cartridge.","inputs":[]},{"name":"Harden the strip","process":"heat-treat","text":"The ribbon runs through a hardening furnace and an abrupt quench, then a tempering furnace that adds toughness.","inputs":[]},{"name":"Grind the wedge","process":"grind","text":"Abrasive wheels grind both faces of the edge down in stages, until they meet at a fine tip.","inputs":[]},{"name":"Coat the edge","process":"deposit","text":"Blades are stacked with their edges aligned, and a hard layer of metal such as chromium is sputtered on. A fluoropolymer is then applied and heated until it clings to the edge, so it glides across skin.","inputs":["chromium","ptfe"]},{"name":"Cut into blades","process":"cut","text":"The ribbon is chopped into single blades, which drop into cartridges or onto handles.","inputs":[]}],"facts":["The oldest razor-like object has been dated to 18,000 BC.","Stainless steel blades that could be used more than once appeared in 1960 from the Wilkinson firm of Sheffield.","Early safety-razor blades were meant to be thrown away after a single use because they were so hard to sharpen."],"where":[],"whereNote":null,"sources":[{"title":"Razor","url":"https://en.wikipedia.org/wiki/Razor"},{"title":"Quenching","url":"https://en.wikipedia.org/wiki/Quenching"},{"title":"Razor blades (US3501334)","url":"https://patents.google.com/patent/US3501334A/en"},{"title":"Razor blade, razor head, and method of manufacture (US10744660)","url":"https://patents.google.com/patent/US10744660"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rebar","name":"Rebar","kind":"product","category":"metals","title":"How rebar is made","url":"https://assemblyline.org/make/rebar","stations":6,"upstream":38,"downstream":2,"depth":7,"dek":"Concrete is strong when squeezed and weak when stretched, so steel bars with ridges do the stretching for it.","answer":"Rebar is rolled from steel billets that are heated until they are glowing and squeezed into round bars. The last roll stand presses ribs, or lugs, into the surface so concrete can grip the bar. The bars are cut to length, sometimes coated with zinc or epoxy to resist corrosion, and bundled for delivery to building sites.","aka":["reinforcing bar","reinforcing steel","deformed bar"],"inputs":["steel","steel-scrap","zinc","epoxy"],"uses":["concrete","skyscraper"],"grounds":["zinc-ore","air","iron-ore","limestone","dolomite","water","manganese-ore","natural-gas","crude-oil","sulfur","rock-salt","coal","quartz","timber"],"upstreamSlugs":["steel","steel-scrap","zinc","epoxy","pig-iron","magnesium","oxygen","lime","manganese","argon","propane","zinc-ore","air","sulfuric-acid","phenol","propylene","acetone","chlorine","caustic-soda","iron-ore","coke","limestone","dolomite","silicon","water","manganese-ore","natural-gas","crude-oil","sulfur","benzene","naphtha","rock-salt","coal","quartz","charcoal","timber","hydrogen","toluene"],"downstreamSlugs":["concrete","skyscraper"],"steps":[{"name":"Cast square billets","process":"cast","text":"Molten steel is run through a continuous caster that produces billets, thick square bars under 200 millimeters across and up to 12 meters long. Billets are the usual feedstock for long products such as rebar, and rebar is often made entirely from recycled steel scrap.","inputs":["steel","steel-scrap"]},{"name":"Reheat to rolling heat","process":"heat-treat","text":"Cold billets are heated in a furnace until they are soft enough to roll. Those coming straight from a caster can skip this and go in hot.","inputs":[]},{"name":"Roll the round bar","process":"roll","text":"A train of roll stands squeezes the billet thinner and longer, step by step, until it is a round bar of the required diameter. Rolling above the recrystallization temperature keeps the steel from hardening as it is worked.","inputs":[]},{"name":"Emboss the ribs","process":"roll","text":"In the final stand the rolls carry engraved patterns that press raised ribs into the bar. The height and spacing of those lugs are set by standards, because they are what lock the bar into the concrete and stop it sliding out.","inputs":[]},{"name":"Cut to length","process":"cut","text":"Shears cut the cooled bars to lengths for shipping, or the bar is coiled if it is thin. Sizes are labeled by number, so a builder can ask for a standard bar by its size.","inputs":[]},{"name":"Coat against corrosion","process":"coat","text":"Plain carbon steel bars are left uncoated for most buildings, because concrete itself protects them. Bars for bridges and seawater work can be galvanized with zinc or coated in epoxy resin instead.","inputs":["zinc","epoxy"]}],"facts":["Steel and concrete expand and shrink with temperature by almost the same amount, so a reinforced beam does not tear itself apart on hot or cold days.","Epoxy-coated rebar went into over 70,000 US bridge decks, yet by 2005 it was being phased out in favor of stainless steel because it performed poorly.","Concrete keeps rebar from rusting because its chemistry is strongly alkaline, with a pH above 12, so cracks and thin cover let rust in."],"where":[],"whereNote":null,"sources":[{"title":"Rebar","url":"https://en.wikipedia.org/wiki/Rebar"},{"title":"Continuous casting","url":"https://en.wikipedia.org/wiki/Continuous_casting"},{"title":"Hot rolling","url":"https://en.wikipedia.org/wiki/Hot_rolling"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"refrigerant","name":"Refrigerant","kind":"material","category":"chemicals","title":"How refrigerants work and are made","url":"https://assemblyline.org/make/refrigerant","stations":6,"upstream":18,"downstream":3,"depth":4,"dek":"Every fridge and air conditioner relies on a liquid that boils at a carefully chosen temperature.","answer":"A refrigerant has to boil below the cold side's temperature and condense above the warm side's. Natural fluids such as ammonia and carbon dioxide skip the fluorine chemistry. Widely used HFC-134a is built in two reactors, where trichloroethylene meets hydrogen fluoride and chlorine gives way to fluorine. Distillation then pulls off hydrogen chloride and sends unreacted feed back around.","aka":["coolant gas","Freon","R-134a"],"inputs":["fluorspar","sulfuric-acid","chlorine","ammonia","carbon-dioxide","propane"],"uses":["refrigerator","air-conditioner","asthma-inhaler"],"grounds":["fluorspar","sulfur","air","water","rock-salt","natural-gas","corn","limestone","crude-oil","sugarcane","sugar-beet"],"upstreamSlugs":["fluorspar","sulfuric-acid","chlorine","ammonia","carbon-dioxide","propane","sulfur","air","water","rock-salt","natural-gas","corn","yeast","limestone","crude-oil","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["refrigerator","air-conditioner","asthma-inhaler"],"steps":[{"name":"Make hydrogen fluoride","process":"react","inputs":["fluorspar","sulfuric-acid"],"text":"Synthetic fluids begin with fluorite, a mineral that gives off hydrogen fluoride when treated with concentrated sulfuric acid."},{"name":"Swap chlorine for fluorine","process":"react","inputs":["chlorine"],"text":"Trichloroethylene, a chlorine-bearing feedstock, meets hydrogen fluoride in a first reactor. Fluorine takes the place of most of its chlorine, hydrogen chloride comes off, and the result is an intermediate called HCFC-133a."},{"name":"Finish in a second reactor","process":"react","inputs":[],"text":"The intermediate takes on one more fluorine from more hydrogen fluoride, under different conditions from the first step. That gives HFC-134a. Each stage needs its own settings, which is why the job takes two reactors."},{"name":"Distill and recycle","process":"refine","inputs":[],"text":"One patent combines the output of both reactors and feeds it to a distillation column. A second column recovers hydrogen chloride. Unreacted hydrogen fluoride and intermediate get topped up and returned to their reactors, which saves columns and energy over distilling after each step."},{"name":"Purify the fluid","process":"separate","inputs":[],"text":"The product stream still holds small amounts of intermediate and hydrogen fluoride, so it goes to a separate purification step before it is ready to sell."},{"name":"Blend or use natural fluids","process":"mix","inputs":["ammonia","carbon-dioxide","propane"],"text":"Refrigerants are sometimes blended to balance properties, and a blend vaporizes across a small temperature range called glide. Ammonia, carbon dioxide and propane take none of the fluorine route above."}],"facts":["Refrigerants of the late 1920s such as ammonia and sulfur dioxide were toxic, flammable or explosive, which sent Thomas Midgley Jr. looking for a safer fluid.","Thomas Midgley Jr. helped develop both Freon and leaded gasoline, two inventions that later did great harm to the planet."],"where":[],"whereNote":null,"sources":[{"title":"Refrigerant","url":"https://en.wikipedia.org/wiki/Refrigerant"},{"title":"Hydrofluoric acid","url":"https://en.wikipedia.org/wiki/Hydrofluoric_acid"},{"title":"1,1,1,2-Tetrafluoroethane","url":"https://en.wikipedia.org/wiki/1,1,1,2-Tetrafluoroethane"},{"title":"Thomas Midgley Jr.","url":"https://en.wikipedia.org/wiki/Thomas_Midgley_Jr."},{"title":"US5276223A, Process for producing 1,1,1,2-tetrafluoroethane","url":"https://patents.google.com/patent/US5276223"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"refrigerator","name":"Refrigerator","kind":"product","category":"machines","title":"How refrigerators are made","url":"https://assemblyline.org/make/refrigerator","stations":11,"upstream":88,"downstream":0,"depth":10,"dek":"Nitrogen runs through a fridge's tubing before any refrigerant does, and a machine sniffs for leaks at the very end.","answer":"Nitrogen goes through a refrigerator's tubing before any refrigerant does, because it exposes bad joints safely. Earlier on the line, sheet metal is welded or clinched into a shell, a vacuum-formed plastic liner snaps inside, and polyurethane foam swells to fill the gap. Copper coils and a compressor are attached, the sealed circuit gets its charge, and each unit runs with sensors inside.","aka":["fridge","fridge-freezer","icebox"],"inputs":["sheet-steel","paint","plastic","polyurethane","copper","aluminum","solder","electric-motor","refrigerant"],"uses":[],"grounds":["water","natural-gas","copper-ore","air","crude-oil","coal","fluorspar","zinc-ore","titanium-ore","iron-ore","sulfur","rock-salt","bauxite","tin-ore","lead-ore","silver-ore","corn","limestone","dolomite","manganese-ore","quartz","timber","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["sheet-steel","paint","plastic","polyurethane","copper","aluminum","solder","electric-motor","refrigerant","steel","zinc","water","titanium-dioxide","pigment","acrylic","tin-can","naphtha","natural-gas","ethylene","propylene","nitric-acid","chlorine","copper-ore","oxygen","air","sulfuric-acid","crude-oil","coal","petroleum-coke","alumina","tin","lead","silver","copper-wire","epoxy","ball-bearing","fluorspar","ammonia","carbon-dioxide","propane","pig-iron","magnesium","steel-scrap","lime","manganese","argon","zinc-ore","titanium-ore","coke","iron-ore","carbon-black","sulfur","methanol","tinplate","lacquer","ink","hydrogen","rock-salt","bauxite","caustic-soda","tin-ore","lead-ore","silver-ore","phenol","acetone","steel-wire","corn","yeast","limestone","dolomite","silicon","manganese-ore","ethanol","vegetable-oil","phenolic-resin","benzene","molasses","quartz","charcoal","timber","sugarcane","soybeans","rapeseed","hexane","clay","formaldehyde","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Weld the outer shell","process":"weld","text":"Steel or aluminum sheet comes off a coil and its pieces are welded or clinched. Clinching crimps two sheets together under pressure with no added fastener. Seams that will show get welded and ground down until they read as one piece.","inputs":["sheet-steel"]},{"name":"Paint the bare metal","process":"coat","text":"Sheet bought precoated skips this step. Other parts are sprayed, or dipped in a paint and solvent bath and then heated so the coat bakes on.","inputs":["paint"]},{"name":"Vacuum form the liners","process":"mold","text":"A thick plastic sheet, a little oversize, is clamped at its edges and heated. Suction pulls it into a mold, where it cools, and the excess is trimmed off. Inner doors are nearly always made this way.","inputs":["plastic"]},{"name":"Nest liner inside shell","process":"assemble","text":"The inner cabinet snaps into the outer one. Some tubes and wires are threaded through the gap between the walls while it is still empty.","inputs":[]},{"name":"Foam the wall gap","process":"fill","text":"A robot or a long manual gun shoots foam between the walls, and an oven makes it expand into a stiff, insulating core. One patent describes mixing liquid polyol and isocyanate into polyurethane, with vent holes to let trapped air escape ahead of the foam. Doors get the same treatment.","inputs":["polyurethane"]},{"name":"Attach the cooling circuit","process":"assemble","text":"Copper tube is cut, bent and soldered into condenser and evaporator coils, which arrive at the cabinet as a unit. Screws and clips hold the other cooling parts, the joints are soldered, and a protective coating is sprayed over them. Fins of aluminum or alloy add surface area on some designs. The compressor, a sealed motor and pump, is mounted at the base.","inputs":["copper","aluminum","solder","electric-motor"]},{"name":"Hang the doors","process":"assemble","text":"Gaskets loaded with magnets are screwed onto each door to make the seal. Handles and hinges go on next, and the hinges are screwed to the cabinet with some room for adjustment.","inputs":[]},{"name":"Pressure test with nitrogen","process":"inspect","text":"Tubing subassemblies, and then the whole unit, are filled with nitrogen to reveal flaws in the tube or the solder. Nitrogen is a safe gas to use for this.","inputs":[]},{"name":"Charge the sealed loop","process":"fill","text":"Units that pass receive their refrigerant. The main type now used in Europe is isobutane, labeled R-600a, a replacement for gases that harmed the ozone layer.","inputs":["refrigerant"]},{"name":"Run and sniff for leaks","process":"inspect","text":"Sensors inside the running unit track its temperature over time to confirm it reaches design levels, including during defrost. A machine that detects refrigerant then gives it a final sniff. If a charged unit is rejected, special equipment drains the gas for reuse.","inputs":[]},{"name":"Tape in shelves and pack","process":"assemble","text":"Shelves, crispers and ice trays go in and are taped down for the trip. The unit gets a last look before it is packaged for shipping.","inputs":["plastic"]}],"facts":["Clinching joins two metal sheets much the way a stapler does, except that no staple is involved.","To work out where foam should go, engineers once filled complete fridge cabinets by trial and error, then ripped them apart to see the result.","Governments banned the refrigerant R-12 in new refrigerators in 1994 because it damaged the ozone layer."],"where":[],"whereNote":null,"sources":[{"title":"Refrigerator, How Products Are Made","url":"https://encyclopedia.com/manufacturing/news-wires-white-papers-and-books/refrigerator"},{"title":"US5740074A, Method for filling a compartment cavity with foam","url":"https://patents.google.com/patent/US5740074A/en"},{"title":"Refrigerator","url":"https://en.wikipedia.org/wiki/Refrigerator"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"remote-control","name":"Remote control","kind":"product","category":"electronics","title":"How remote controls are made","url":"https://assemblyline.org/make/remote-control","stations":7,"upstream":96,"downstream":0,"depth":10,"dek":"Most TV remotes are not radios. They blink an invisible infrared light in a coded pattern.","answer":"Under each rubber key sits a conductive carbon or gold pill that closes a circuit when pressed. Factories mold the plastic case from resin in steel molds, cure silicone into keypads, and run the circuit boards through pick-and-place machines and a reflow oven. An assembly line then stacks board, keypad and top case, and an electronic fixture tests each finished unit.","aka":["TV remote","clicker","remote"],"inputs":["abs-plastic","silicone","carbon-black","printed-circuit-board","microchip","led","solder","cardboard-box"],"uses":[],"grounds":["air","water","silica-sand","crude-oil","natural-gas","iron-ore","sulfur","quartz","coal","timber","copper-ore","limestone","tin-ore","gold-ore","bauxite","zinc-ore","lead-ore","silver-ore","titanium-ore","rock-salt","trona","soybeans","rapeseed","clay","corn","sugarcane","sugar-beet"],"upstreamSlugs":["abs-plastic","silicone","carbon-black","printed-circuit-board","microchip","led","solder","cardboard-box","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","silicon","methanol","hydrochloric-acid","water","silica-sand","crude-oil","copper","fiberglass","epoxy","photoresist","silicon-wafer","oxygen","tin","aluminum","gold","gallium","indium","hydrogen","plastic","lead","silver","cardboard","ink","adhesive","natural-gas","toluene","iron-ore","titanium-dioxide","sulfur","quartz","coke","coal","charcoal","timber","chlorine","copper-ore","sulfuric-acid","limestone","soda-ash","phenol","acetone","caustic-soda","phenolic-resin","polysilicon","argon","tin-ore","petroleum-coke","alumina","gold-ore","lime","zinc","bauxite","zinc-ore","lead-ore","silver-ore","wood-pulp","vegetable-oil","ethanol","polyethylene","acrylic","polyurethane","paraffin-wax","titanium-ore","rock-salt","carbon-dioxide","trona","formaldehyde","trichlorosilane","nitrogen","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","corn","sugarcane","yeast","nitric-acid","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the case","process":"mold","inputs":["abs-plastic"],"text":"Molten resin goes into steel molds and comes out as the enclosure. Before anything reaches the line, inspectors compare parts with approved samples and check colors against color books."},{"name":"Cure the keypad","process":"mold","inputs":["silicone","carbon-black"],"text":"Silicone rubber starts out like a thick gel, goes into a mold, and sets solid under heat and pressure. Colored sheets give custom keypads. A carbon or gold pill sits under each button, separated from the board by a springy web."},{"name":"Place the components","process":"assemble","inputs":["printed-circuit-board","microchip","led","solder"],"text":"Pick-and-place machines set the microcontroller, capacitors, resistors and LEDs on the fabricated board. An optical check follows, then a reflow oven fixes the solder."},{"name":"Test and program boards","process":"inspect","inputs":[],"text":"Every board goes through in-circuit testing to prove its parts work. The microcontroller is programmed here on a special fixture, or later once the remote is assembled."},{"name":"Stack the shell","process":"assemble","inputs":[],"text":"Stations along an assembly line drop the board into the enclosure, lay the rubber keypad over it and attach the top case."},{"name":"Check on a fixture","process":"inspect","inputs":[],"text":"An electronic test fixture confirms each unit works, and staff check its looks and keep the inspection records."},{"name":"Pack and ship","process":"package","inputs":["cardboard-box"],"text":"Finished remotes go into gift boxes, clamshells or bulk packs, then onto pallets for ocean freight or into export cartons for air."}],"facts":["In 1904, Leonardo Torres Quevedo tested a radio-controlled system on a three-wheeled vehicle with a range of 20 to 30 meters.","One of the first TV remotes, Zenith's Lazy Bones of 1950, ran on a wire to the set."],"where":[],"whereNote":null,"sources":[{"title":"Help, I Need a Custom Remote Control for My Product! (Part 3)","url":"https://celadon.com/help-i-need-a-custom-remote-control-for-my-product-part-3"},{"title":"How Silicone Rubber Keypads Are Made","url":"https://nelson-miller.com/how-silicone-rubber-keypads-are-made"},{"title":"Remote control","url":"https://en.wikipedia.org/wiki/Remote_control"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rice","name":"Rice","kind":"raw","category":"farm","title":"How rice is grown and harvested","url":"https://assemblyline.org/make/rice","stations":3,"upstream":0,"downstream":5,"depth":0,"dek":"Most of the world's rice is still transplanted by hand, one bundle of seedlings at a time, into flooded fields.","answer":"Rice starts as seedlings raised in a nursery bed and then planted into a flooded paddy. The crop is harvested when the grain holds 20 to 25% moisture. Stalks are cut and stacked, threshed to knock the grain loose, cleaned by winnowing or screening, and dried quickly so that mold cannot grow.","aka":["paddy rice","rice farming","rice harvest","paddy"],"inputs":[],"uses":["beer","sake","white-rice","koji"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["beer","sake","white-rice","koji","soy-sauce"],"steps":[{"name":"Transplant the seedlings","process":"grow","text":"Seed can be scattered straight onto the field, which needs 60 to 80 kilograms per hectare. Transplanting seedlings from a bed needs only around 40 kilograms per hectare but far more labor, and most rice in Asia is still transplanted by hand.","inputs":[],"spec":"about 40 kg of seed per hectare"},{"name":"Flood the paddy","process":"grow","text":"Paddy fields are kept under water for much of the season. Long flooding stops oxygen from reaching the soil, so organic matter ferments and releases methane. Wetting and drying in turn can cut those emissions by up to 90%.","inputs":[]},{"name":"Reap, thresh and dry","process":"harvest","text":"Once the grain reaches 20 to 25% moisture, it is reaped, stacked, threshed and winnowed. The paddy rice is dried as soon as possible, traditionally in the sun on mats or pavements, to a level that is safe from mold fungi.","inputs":[]}],"facts":["Rice was first domesticated in China about 9,000 years ago.","Yuan Longping set a yield record in 1999 of 17.1 metric tons per hectare, against a world average of 4.7 in 2022.","Rice ranks third among all crops by production, behind sugarcane and maize."],"where":[{"place":"China and India combined","share":"52% of world output"}],"whereNote":"2023, share of the 800 million tonnes of rice produced worldwide. About 90% of the total comes from Asia.","sources":[{"title":"Rice","url":"https://en.wikipedia.org/wiki/Rice"},{"title":"Paddy field","url":"https://en.wikipedia.org/wiki/Paddy_field"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"coffee","name":"Roasted coffee","kind":"product","category":"drink","title":"How coffee is made","url":"https://assemblyline.org/make/coffee","stations":8,"upstream":2,"downstream":1,"depth":1,"dek":"A tonne of fresh coffee cherries yields only about 200 kilograms of green beans.","answer":"Coffee beans are the seeds inside red cherries. Pickers harvest the cherries, mills strip away the fruit and dry the seeds, and a hulling machine removes the last papery layers. The green beans are then roasted in a spinning drum until they swell, crack and brown, cooled quickly, and ground and packed.","aka":["coffee beans","roasted coffee","ground coffee"],"inputs":["coffee-cherries","water"],"uses":["instant-coffee"],"grounds":["coffee-cherries","water"],"upstreamSlugs":["coffee-cherries","water"],"downstreamSlugs":["instant-coffee"],"steps":[{"name":"Pick the ripe cherries","process":"harvest","text":"About eight months after the cherries appear, they are picked by hand or by machine. Brazil's huge flat fields are mechanized, while most other countries still pick by hand.","inputs":["coffee-cherries"]},{"name":"Float away the duds","process":"separate","text":"In the wet process the crop is graded by airflow, screens and water. Light cherries rise and are skimmed off, and heavier ripe ones sink.","inputs":[]},{"name":"Strip off the fruit","process":"wash","text":"A pulper separates the skin and pulp from the seeds. The slimy layer left on the seeds is removed by fermenting it with microbes and rinsing, or by scrubbing it off in a machine.","inputs":["water"],"spec":"twelve to thirty-six hours of fermenting"},{"name":"Dry them in the sun","process":"dry","text":"Washed coffee leaves the mill soaked with water. It is spread on patios or raised beds, or dried with heated air, until it has fallen to a stable moisture level. About 90 per cent of Brazilian arabica skips washing and is dried inside the whole fruit.","inputs":[],"spec":"from 53% to 10–12% moisture"},{"name":"Hull and grade the beans","process":"separate","text":"A hulling machine removes the dry parchment or husk, leaving the green bean. The beans are then cleaned, sorted by size and bagged for export.","inputs":[]},{"name":"Roast in a spinning drum","process":"bake","text":"Green beans tumble in a hot drum. Heat starts the browning reactions that create the flavor. Around 175 °C the beans start giving off heat themselves, and at about 196 °C they crackle as they swell. A dark roast reaches the second crack near 224 °C.","inputs":[],"spec":"beans lose 15 to 18% of their mass"},{"name":"Quench and cool","process":"chill","text":"The beans are dumped out and cooled fast with air or a water mist. A quick cool halts the roasting before the flavor over-develops.","inputs":[]},{"name":"Grind and seal","process":"package","text":"Beans are packed whole or ground. Roasted coffee gives off carbon dioxide for days, so bags have valves that let the gas out and keep air away.","inputs":[]}],"facts":["The beans roughly double in volume during roasting, much like popcorn, because steam builds up inside them.","Arabica accounts for almost 60 per cent of world output, down from about 75 per cent in 1965.","Roasted coffee has a typical shelf life of two weeks, while ground coffee goes stale in about 15 minutes.","Roasters usually work near where the coffee will be drunk, since green coffee keeps better than roasted beans."],"where":[],"whereNote":null,"sources":[{"title":"Coffee production","url":"https://en.wikipedia.org/wiki/Coffee_production"},{"title":"Coffee roasting","url":"https://en.wikipedia.org/wiki/Coffee_roasting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rock-salt","name":"Rock salt","kind":"raw","category":"ground","title":"How rock salt is mined","url":"https://assemblyline.org/make/rock-salt","stations":3,"upstream":0,"downstream":447,"depth":0,"dek":"The world's largest underground salt mine sits half a kilometer under Lake Huron.","answer":"Rock salt is the mineral halite, left behind in thick beds when ancient seas and lakes dried up. Miners drill and blast rooms in the bed, leaving pillars of salt to hold up the roof. Machines load and haul the broken salt to the surface, where it is crushed and screened.","aka":["halite","mined salt"],"inputs":[],"uses":["soap","shampoo","bleach","soda-ash","chlorine","caustic-soda","table-salt","baking-soda","leather"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["soap","shampoo","bleach","soda-ash","chlorine","caustic-soda","table-salt","baking-soda","leather","kitchen-sponge","detergent","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","instant-noodles","stained-glass","vanadium","pvc","polycarbonate","epoxy","polyurethane","ptfe","kevlar","titanium-dioxide","nitrile-glove","titanium","gold","hydrochloric-acid","refrigerant","spandex","iridium","aspirin","glycerin","alumina","pretzel","gallium","superabsorbent-polymer","polyvinyl-alcohol","wood-pulp","rayon","butter","cheese","margarine","mayonnaise","ketchup","mustard","soy-sauce","peanut-butter","bread","croissant","corn-flakes","potato-chips","popcorn","hot-dog","bacon","canned-tuna","chicken-nuggets","cream-cheese","mozzarella","parmesan","cheddar","oat-milk","hot-sauce","salsa","pickles","sauerkraut","kimchi","bagel","baguette","sourdough","crackers","imitation-crab","sausage","salami","ham","beef-jerky","canned-meat","sausage-casing","modeling-clay","caramel","cake-mix","dish-soap","sparkling-water","frozen-pizza","fire-extinguisher","wristwatch","baseball","basketball","ice-skates","tennis-racket","football","saxophone","winter-gloves","leather-belt","handbag","wallet","hiking-boots","high-heels","digital-camera","leather-shoe","printed-circuit-board","wind-turbine","surfboard","ski","snowboard","fishing-rod","kite","roof-shingle","vinyl-floor","canoe","sailboat","umbrella","lithium-ion-cell","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","dumbbell","stent","wrench","nichrome","thermometer","lcd-screen","oled-screen","camera-sensor","solar-panel","microwave-oven","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","floor-tile","neon-sign","smartwatch","e-reader","mirror","skyscraper","windshield","double-glazed-window","nail-polish","perfume","penicillin","insulin","vaccine","cola","beer","wine","champagne","whiskey","vodka","gin","rum","tequila","sake","hard-cider","soda","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","port-wine","prosecco","non-alcoholic-beer","smartphone","credit-card","plastic-wrap","dishwasher","garden-hose","volleyball","yoga-mat","action-figure","fashion-doll","globe","inflatable-pool-toy","chain-link-fence","pvc-pipe","power-cable","smoke-detector","flip-flops","usb-cable","vinyl-record","led-bulb","drone","bike-helmet","blender","suitcase","wireless-earbuds","phone-charger","camera-lens","compact-disc","game-console","adhesive","electric-motor","rebar","aluminum-can","airplane","prosthetic-leg","loudspeaker","adhesive-bandage","pacemaker","refrigerator","car","skateboard","golf-ball","soccer-ball","hardwood-floor","sofa","office-chair","roller-skates","wheelchair","underwear","leggings","swimsuit","raincoat","backpack","sneaker","mattress","nonstick-pan","brake-pad","toothpaste","sunscreen","lipstick","ink","paint","crayon","pencil-eraser","candy-coated-chocolate","foundation-makeup","pigment","jet-engine","drill-bit","microchip","led","needle","gold-ring","fountain-pen","gold-bar","medal","deodorant","silicone","polysilicon","platinum","trichlorosilane","germanium","air-conditioner","asthma-inhaler","chewing-gum","cough-syrup","gelatin-capsule","aluminum","laminate-floor","spark-plug","sanitary-pad","diaper","pvb","banknote","cellulose-acetate","paper","cardboard","toilet-paper","facial-tissue","tampon","toffee","fish-sticks","hearing-aid","ev-battery","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","washing-machine","satellite","electric-car","airbag","rocket","locomotive","motorcycle","elevator","ceiling-fan","treadmill","pinball-machine","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","syringe","electric-kettle","kitchen-knife","fork","thermos","water-bottle","pressure-cooker","golf-club","subway-train","eyeglass-frame","jam","hazelnut-spread","aluminum-window-frame","air-freshener","hairspray","aa-battery","candy-cane","duct-tape","pencil","nail","insulation","guitar","piano","violin","drum-kit","tennis-ball","paper-straw","paper-bag","pizza-box","wooden-chair","door","clear-tape","staple","cricket-bat","dartboard","chess-set","board-game","jigsaw-puzzle","ukulele","cello","drumstick","cotton-swab","dress-shirt","suit","microphone","plywood","mdf","cardboard-box","book","envelope","sticky-notes","playing-cards","match","baseball-cap","carpet","vacuum-cleaner","concrete","energy-drink","light-beer","insect-repellent","plastic-bag","tin-can","rubiks-cube","ballpoint-pen","paper-cup","wallpaper","marker-pen","highlighter","frisbee","trading-cards","flag","newspaper","t-shirt","scissors","container-ship","shipping-container","bicycle","billiard-ball","dice","toy-car","coil-spring","hammer","wheelbarrow","gas-cylinder","suspension-bridge-cable","toothbrush","mascara","abs-plastic","lego-brick","porcelain","chalk","sprinkles","plastic-straw","printer-toner","eyeshadow","towel","condom","contact-lens","cork-stopper","silicon-wafer","solar-cell","aluminum-foil","brass","cobalt","car-engine","yo-yo","ladder","zipper","n95-mask","shoelace","drywall","fireworks","egg-carton","hair-dye","paperclip","donut","cotton-candy","candle","zip-bag","pillow","mouthwash","light-switch","condensed-milk","baby-formula","coconut-milk","canned-soup","padlock","3d-printer-filament","headphones","harmonica","memory-chip","tire","electric-guitar","trumpet","guitar-string","hinge","key","power-outlet","tungsten-carbide","down-jacket","jeans","saw-blade"],"steps":[{"name":"Drill into the bed","process":"mine","text":"Salt beds can be hundreds of meters thick. Shafts are sunk into them, and drills bore holes along the face of the salt.","inputs":[]},{"name":"Blast the rooms","process":"mine","text":"Explosives break the salt face into chunks, and loaders haul it away. Pillars of untouched salt are left standing between the rooms to hold the roof up.","inputs":[]},{"name":"Crush and screen","process":"crush","text":"Hoisted to the surface, the salt is crushed and screened into sizes for de-icing roads, for chemical plants and for further refining.","inputs":[]}],"facts":["The earliest found salt mine, at Hallstatt in Austria, was mining salt from 5000 BC.","Ancient Chinese diggers found natural gas while excavating rock salt.","The Sifto mine's rooms are cut by the room and pillar method, leaving salt pillars to hold the roof up."],"where":[],"whereNote":null,"sources":[{"title":"Halite","url":"https://en.wikipedia.org/wiki/Halite"},{"title":"Salt mining","url":"https://en.wikipedia.org/wiki/Salt_mining"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"oatmeal","name":"Rolled oats","kind":"product","category":"food","title":"How rolled oats are made","url":"https://assemblyline.org/make/oatmeal","stations":6,"upstream":1,"downstream":1,"depth":1,"dek":"Oats are steamed before they are flattened, because the bran carries an enzyme that turns them rancid.","answer":"Harvested oats are cleaned, then dehulled to leave the inner seed, called a groat. Steam heats the groats to switch off an enzyme that would turn them rancid. They are then rolled flat between heavy rollers and lightly toasted. Thinner flakes steamed longer become quick oats, and cut groats become steel-cut oats.","aka":["oatmeal","old-fashioned oats","porridge oats","quick oats"],"inputs":["oats"],"uses":["granola-bar"],"grounds":["oats"],"upstreamSlugs":["oats"],"downstreamSlugs":["granola-bar"],"steps":[{"name":"Clean the grain","process":"separate","text":"Screens and air remove weed seeds, stones and other foreign material from the harvested oats.","inputs":["oats"]},{"name":"Strip off the hulls","process":"separate","text":"Dehulling removes the inedible outer husk and leaves the bran-covered seed, called a groat.","inputs":[]},{"name":"Steam the groats","process":"cook","text":"Steam softens the groats for quicker cooking and denatures enzymes in the bran that would otherwise make the oats go sour or rancid. That gives them a longer shelf life.","inputs":[]},{"name":"Roll them flat","process":"roll","text":"Heavy rollers squash each groat into a flake. Thick flakes stay whole and are sold as old-fashioned oats. Thinner flakes, steamed more, fragment but absorb water faster and are marketed as quick oats.","inputs":[]},{"name":"Toast to stabilize","process":"bake","text":"A light toasting dries and stabilizes the flakes. Steel-cut oats skip rolling and are chopped by a sharp-bladed machine before any steaming.","inputs":[]},{"name":"Pack the flakes","process":"package","text":"Flakes are poured into canisters and bags for the shelf.","inputs":[]}],"facts":["Steel-cut oats never meet the rollers. A sharp-bladed machine chops the groats before any steaming.","Quaker Oats introduced instant oatmeal in 1966."],"where":[],"whereNote":null,"sources":[{"title":"Rolled oats","url":"https://en.wikipedia.org/wiki/Rolled_oats"},{"title":"Oat","url":"https://en.wikipedia.org/wiki/Oat"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"roller-skates","name":"Roller skates","kind":"product","category":"play","title":"How roller skates are made","url":"https://assemblyline.org/make/roller-skates","stations":8,"upstream":49,"downstream":0,"depth":8,"dek":"A skate wheel is molded twice: a hard nylon core first, then a polyurethane tire shot around it.","answer":"A roller skate is a boot fixed to a frame or plate that carries the wheels. Inline boots are injection-molded shells with a soft liner, while quad skates usually use a high-top boot or a flat-soled one. Each wheel is a molded core wrapped in polyurethane, with two ball bearings in its hub. Bolts or rivets join boot and frame.","aka":["quad skates","inline skates","rollerblades"],"inputs":["polyurethane","plastic","nylon","ball-bearing","bolt","rubber"],"uses":[],"grounds":["water","natural-gas","natural-latex","sulfur","crude-oil","air","rock-salt","zinc-ore","coal","iron-ore","limestone","dolomite","manganese-ore","quartz","timber"],"upstreamSlugs":["polyurethane","plastic","nylon","ball-bearing","bolt","rubber","propylene","nitric-acid","chlorine","water","naphtha","natural-gas","ethylene","benzene","ammonia","steel-wire","steel","sheet-steel","zinc","natural-latex","synthetic-rubber","carbon-black","sulfur","crude-oil","air","rock-salt","sulfuric-acid","hydrogen","toluene","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","styrene","coal","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","quartz","charcoal","timber"],"downstreamSlugs":[],"steps":[{"name":"Mold the boot shell","process":"mold","text":"Urethane plastic with dye for color is injected into a mold, cools, and is ejected as a finished shell. Quad boots come in two styles: a high-top with a raised heel, or a flat-soled boot cut at or below the ankle.","inputs":["polyurethane"]},{"name":"Fit the liner and straps","process":"assemble","text":"A liner of soft cloth or plastic foam is cut to the boot's size and fitted inside. Bought-in parts such as the cuff, straps and metal buckles are attached.","inputs":["plastic"]},{"name":"Mold the wheel core","process":"mold","text":"Nylon or Rilsan granules, often mixed with carbon for strength, are melted and injected into a steel mold. The core does the job of a rim.","inputs":["nylon"]},{"name":"Shoot polyurethane around it","process":"mold","text":"The core moves to a second mold, and molten polyurethane is injected around it to form the tire. Some makers pour the urethane instead. The wheel then cools and comes out.","inputs":["polyurethane"]},{"name":"Seat the bearings","process":"assemble","text":"Two ball bearings go into each wheel hub so it spins freely on the axle. Skates have carried ball bearings since the 1880s.","inputs":["ball-bearing"]},{"name":"Mount the wheels","process":"assemble","text":"Wheels are secured on axles in the plate, or in a row in an inline frame. On a quad skate the axles pivot, so leaning to one side steers the skate.","inputs":["bolt"]},{"name":"Join boot and frame","process":"assemble","text":"An inline frame is riveted to the shell or fixed by a coupling system. A quad plate is bolted on through holes drilled in the sole, with low-profile bolt heads inside the boot and nuts facing the floor.","inputs":["bolt"]},{"name":"Add the brake","process":"assemble","text":"Inline skates typically get a rubber brake attached to the frame, at the back of one skate.","inputs":["rubber"]}],"facts":["The first reported use of wheeled skates was on a London stage in 1743.","Early polyurethane wheels were too grippy and slow for wooden rink floors, so skaters at first preferred wheels of clay or rubber mixed with fibers.","Two years can pass between a new skate wheel's first design and mass production, and the mold alone takes almost six months."],"where":[],"whereNote":null,"sources":[{"title":"Roller skates","url":"https://en.wikipedia.org/wiki/Roller_skates"},{"title":"Inline skates","url":"https://en.wikipedia.org/wiki/Inline_skates"},{"title":"How are made skate wheels?","url":"https://en.rollerenligne.com/materiel/how-are-made-skate-wheels"},{"title":"How roller skates are made","url":"https://tomorrowsworldtoday.com/?p=6424"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"roof-tile","name":"Roof tile","kind":"product","category":"minerals","title":"How roof tiles are made","url":"https://assemblyline.org/make/roof-tile","stations":6,"upstream":2,"downstream":0,"depth":1,"dek":"Interlocking roof tiles can only be made with a press, which is why they arrived with factories in the 1840s.","answer":"Clay roof tiles are made by mixing clay with water, forming the paste by extrusion or in a tile press, drying it, optionally glazing it, and firing it in a kiln.","aka":["clay roof tile","terracotta tile","roofing tile"],"inputs":["clay","water"],"uses":[],"grounds":["clay","water"],"upstreamSlugs":["clay","water"],"downstreamSlugs":[],"steps":[{"name":"Dig the clay","process":"mine","text":"Roof tiles are traditionally made from locally available materials, with clay and slate the oldest choices. The clay is dug from a pit near the tileworks.","inputs":["clay"]},{"name":"Temper it with water","process":"mix","text":"The clay is cleaned, blended and worked with water to make a smooth, plastic paste that holds its shape when squeezed.","inputs":["water"]},{"name":"Press or extrude the profile","process":"press","text":"Simple S-shaped Spanish tiles and the Scandia tiles of Northern Europe are traditionally formed through an extruder. Interlocking tiles carry a ridge and can only be made with a tile press.","inputs":[]},{"name":"Dry the green tiles","process":"dry","text":"Shaped tiles are dried until the water has left the clay. Dry clay is brittle, so the tiles are handled carefully until they are fired.","inputs":[]},{"name":"Brush on a glaze","process":"coat","text":"Some tiles are given a glaze, a glassy coating that fuses in the kiln. Glazed tiles were standardized in China during the Song dynasty, and Chinese architecture is known for colored gloss glazes on roofs.","inputs":[]},{"name":"Fire in a kiln","process":"fire","text":"A kiln firing fuses the clay particles into a hard, weatherproof ceramic. Fired clay tile also resists fire, and medieval towns encouraged it as a way to stop fires from spreading.","inputs":[]}],"facts":["Fired roof tiles have been found at the House of the Tiles in Lerna, Greece.","Near Corinth, between 700 and 650 BC, fired tiles began replacing thatch on two temples, and within fifty years they were found at many sites around the Eastern Mediterranean.","In Indonesia, approximately 90% of houses on Java use clay roof tile."],"where":[],"whereNote":null,"sources":[{"title":"Roof tiles","url":"https://en.wikipedia.org/wiki/Roof_tiles"},{"title":"Terracotta","url":"https://en.wikipedia.org/wiki/Terracotta"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"root-beer","name":"Root beer","kind":"product","category":"drink","title":"How root beer is made","url":"https://assemblyline.org/make/root-beer","stations":5,"upstream":56,"downstream":0,"depth":9,"dek":"The FDA banned safrole, the oil in sassafras, in 1960, so root beer now uses imitation or safrole-free flavor.","answer":"Root beer was once brewed from molasses syrup, sassafras root and bark, and yeast, then bottled to fizz. Today a flavor extract is mixed into sweetened carbonated water instead. Since the FDA banned safrole, the sassafras oil, in 1960, most brands use artificial sassafras flavoring or a safrole-free extract.","aka":["sassafras soda","root soda"],"inputs":["sugar","molasses","water","carbon-dioxide","glass-bottle","aluminum-can"],"uses":[],"grounds":["water","sugarcane","sugar-beet","natural-gas","corn","limestone","silica-sand","rock-salt","trona","crude-oil","coal","air","bauxite","soybeans","rapeseed","clay","titanium-ore","iron-ore","sulfur"],"upstreamSlugs":["sugar","molasses","water","carbon-dioxide","glass-bottle","aluminum-can","sugarcane","sugar-beet","lime","natural-gas","corn","yeast","limestone","silica-sand","soda-ash","polyethylene","aluminum","ink","epoxy","rock-salt","ammonia","trona","ethylene","crude-oil","coal","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","phenol","propylene","acetone","chlorine","caustic-soda","air","naphtha","bauxite","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","coke","oxygen","sulfuric-acid","iron-ore","sulfur","benzene","hydrogen","methanol","toluene"],"downstreamSlugs":[],"steps":[{"name":"Prepare the root flavor","process":"mix","text":"Roots and bark such as sassafras and wintergreen give the drink its taste. Since the FDA banned safrole, most brands use an artificial flavoring or an extract with the safrole removed.","inputs":[]},{"name":"Sweeten the base","process":"mix","text":"A syrup is made from sugar or molasses and water, then combined with the flavor extract.","inputs":["sugar","molasses","water"]},{"name":"Build the foam","process":"mix","text":"Sassafras bark makes a long-lasting natural foam. Some makers add small amounts of starch with natural surfactants to the syrup to copy it.","inputs":[]},{"name":"Carbonate the drink","process":"react","text":"Carbon dioxide is dissolved in water under pressure, and the flavored syrup is blended in. Makers moved to this method from fermentation as demand grew.","inputs":["carbon-dioxide","water"]},{"name":"Bottle it","process":"fill","text":"The finished drink is bottled or canned under pressure so it stays fizzy.","inputs":["glass-bottle","aluminum-can"]}],"facts":["Charles Elmer Hires wanted to call his drink root tea, but chose root beer to appeal to Pennsylvania coal miners.","Old recipes fermented the syrup with yeast for about 12 hours, then bottled it for a second fermentation, which gave a fizzy drink of 2 percent alcohol or less.","Laboratory animals fed large doses of safrole developed liver damage and cancer, which led to the 1960 FDA ban."],"where":[],"whereNote":null,"sources":[{"title":"Root beer","url":"https://en.wikipedia.org/wiki/Root_beer"},{"title":"Sassafras","url":"https://en.wikipedia.org/wiki/Sassafras"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rope","name":"Rope","kind":"product","category":"textiles","title":"How rope is made","url":"https://assemblyline.org/make/rope","stations":5,"upstream":14,"downstream":1,"depth":6,"dek":"A rope stays together because every layer is twisted opposite to the one below, so the twists pull against each other.","answer":"Most rope is built from fibers twisted into yarns, yarns twisted into strands, and strands twisted together, each stage in the opposite direction to the last. That counter-twisting locks the rope together and spreads the load. Modern braided rope instead weaves strands into a tube around a core.","aka":["cord","cable","hawser","line"],"inputs":["nylon","polypropylene"],"uses":["kite"],"grounds":["air","water","natural-gas","crude-oil","coal"],"upstreamSlugs":["nylon","polypropylene","benzene","nitric-acid","ammonia","propylene","naphtha","hydrogen","toluene","air","water","natural-gas","crude-oil","coal"],"downstreamSlugs":["kite"],"steps":[{"name":"Spin fibers into yarn","process":"spin","text":"Fibers are gathered and twisted into yarns. Natural fibers include manila hemp, sisal, jute and coir. Synthetic ones such as nylon, polyester and polypropylene are stronger.","inputs":["nylon","polypropylene"]},{"name":"Twist yarns into strands","process":"spin","text":"A number of yarns are twisted together to form a strand. The twist in the strand runs opposite to the twist in the yarn.","inputs":[]},{"name":"Lay the strands","process":"spin","text":"Typically three strands are twisted together in a third direction to lay the rope. Because each level resists the others, the rope does not unravel and the load is shared among the strands.","inputs":[]},{"name":"Braid a jacket instead","process":"weave","text":"For braided rope, an even number of strands, often eight or twelve, are braided into a round tube. In kernmantle rope, a braided sheath wraps a core of long twisted fibers that provides most of the strength.","inputs":[]},{"name":"Seal and reel it","process":"package","text":"Ends are bound or heat-sealed so they do not unravel, and the rope is coiled or wound on reels.","inputs":[]}],"facts":["A 20 cm strip of mammoth ivory with four holes, found in Hohle Fels cave in Germany and dated to between 35,000 and 40,000 years ago, has been identified as a tool for making rope.","From the Middle Ages until the 18th century, European rope was laid in ropewalks, very long buildings where the strands were stretched out and twisted together.","Nylon is 10 to 15 percent weaker when wet."],"where":[],"whereNote":null,"sources":[{"title":"Rope","url":"https://en.wikipedia.org/wiki/Rope"},{"title":"Spinning (textiles)","url":"https://en.wikipedia.org/wiki/Spinning_(textiles)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rough-diamond","name":"Rough diamond","kind":"raw","category":"ground","title":"How rough diamonds are mined","url":"https://assemblyline.org/make/rough-diamond","stations":3,"upstream":0,"downstream":1,"depth":0,"dek":"A diamond mine moves tons of rock to find stones present at no more than parts per billion.","answer":"Most diamonds are carried up from the mantle in kimberlite, a blue-green volcanic rock found in pipes that reach from 75 meters to 1.5 kilometers across. Mines dig out the pipe or the loose gravels weathered from it. The rock is crushed and sorted, with diamonds picked out by density and sometimes glow under X-rays.","aka":["uncut diamond","kimberlite"],"inputs":[],"uses":["cut-diamond"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["cut-diamond"],"steps":[{"name":"Dig out the pipe","process":"mine","text":"Kimberlite sits in narrow dikes and in vertical pipes on the oldest, most stable parts of continents. Miners dig it from open pits that deepen into shafts. Before the 20th century, most diamonds were found in river gravels instead.","inputs":[]},{"name":"Crush the kimberlite","process":"crush","text":"Rock is broken down carefully to free the diamonds without cracking them. Weathered kimberlite, the yellow ground, is easy to break apart.","inputs":[]},{"name":"Sort out the stones","process":"separate","text":"Diamonds are concentrated by density, since they are heavier than most of the waste rock. Between 25% and 35% of natural diamonds fluoresce under X-rays, a property that sorting machines can use to find them.","inputs":[]}],"facts":["Most natural diamonds are between 1 billion and 3.5 billion years old.","Most formed at depths of 150 to 250 kilometers in the Earth's mantle.","Before the 20th century, most diamonds were found in alluvial deposits, not mines.","The only major diamond discoveries since about 1980 have been in Canada."],"where":[],"whereNote":null,"sources":[{"title":"Diamond","url":"https://en.wikipedia.org/wiki/Diamond"},{"title":"Kimberlite","url":"https://en.wikipedia.org/wiki/Kimberlite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rubber-band","name":"Rubber band","kind":"product","category":"wood-paper","title":"How rubber bands are made","url":"https://assemblyline.org/make/rubber-band","stations":6,"upstream":2,"downstream":0,"depth":1,"dek":"A rubber band is a slice of a long rubber tube, which is why it has no seam.","answer":"Rubber arrives at the factory in big bales and is pushed out through a die as a long hollow tube. The tube is slid onto metal rods, heated until the rubber cures, and then sliced across its width. Each slice is a closed loop, so the width of the cut sets how wide the band is and the tube sets how long.","aka":["elastic band","rubber bands"],"inputs":["natural-latex","sulfur"],"uses":[],"grounds":["natural-latex","sulfur"],"upstreamSlugs":["natural-latex","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Break down the bale","process":"knead","text":"Natural or synthetic rubber comes in large bales. Most bands use natural rubber because it stretches better than the synthetic kind. The raw gum is softened and sulfur is worked in, ready for curing later.","inputs":["natural-latex","sulfur"]},{"name":"Push out a long tube","process":"extrude","text":"The softened rubber is forced through a ring-shaped die and comes out as a hollow tube. The thickness of the tube wall decides how strong the finished band will be.","inputs":[]},{"name":"Slide tubes onto rods","process":"assemble","text":"Lengths of tube are fed onto metal rods called mandrels. The rod holds the tube round while it is heated, and its circumference becomes the length of the band.","inputs":[]},{"name":"Cure the rubber","process":"heat-treat","text":"Heat links the rubber molecules together so the band springs back after stretching. Before this step the tube is soft and would stay stretched.","inputs":[]},{"name":"Slice across the tube","process":"cut","text":"Blades chop across the cured tube like a baker slicing a sausage. Every slice falls away as a closed loop with no joint. Slices set closer together make narrower bands.","inputs":[],"spec":"sized by flat length, cut width and wall thickness"},{"name":"Sort by size number","process":"inspect","text":"Bands are sorted and packed under industry size numbers. Lower numbers are narrower, and the numbering restarts for the longest bands.","inputs":[]}],"facts":["Warm a stretched rubber band and it pulls shorter, which is the opposite of what a metal wire does.","A rubber band gives off a little heat as you stretch it and soaks heat up as it relaxes, so it can cool its surroundings slightly.","The first rubber band patent was granted in England in 1845 to Stephen Perry."],"where":[],"whereNote":null,"sources":[{"title":"Rubber band","url":"https://en.wikipedia.org/wiki/Rubber_band"},{"title":"Extrusion","url":"https://en.wikipedia.org/wiki/Extrusion"},{"title":"Vulcanization","url":"https://en.wikipedia.org/wiki/Vulcanization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rubber-boots","name":"Rubber boots","kind":"product","category":"textiles","title":"How rubber boots are made","url":"https://assemblyline.org/make/rubber-boots","stations":6,"upstream":20,"downstream":0,"depth":7,"dek":"Wellington boots began as leather riding boots, and rubber production soared when World War I flooded the trenches.","answer":"A rubber boot is built from several layers: a lining, a body of rubber compound, and a thick molded sole. The compound is mixed, rolled into sheets and cut to pattern. The pieces are stretched by hand over an aluminum boot last, the whole boot is vulcanized to set the rubber, and each one is tested in water.","aka":["wellington boots","wellies","gumboots","rain boots"],"inputs":["natural-latex","synthetic-rubber","sulfur","carbon-black","cotton-fabric"],"uses":[],"grounds":["natural-latex","sulfur","water","crude-oil","air","natural-gas","raw-cotton","corn","coal"],"upstreamSlugs":["natural-latex","synthetic-rubber","sulfur","carbon-black","cotton-fabric","naphtha","benzene","ethylene","styrene","water","crude-oil","air","cotton-yarn","corn-starch","hydrogen","toluene","natural-gas","raw-cotton","corn","coal"],"downstreamSlugs":[],"steps":[{"name":"Mix the rubber compound","process":"mix","text":"Natural and synthetic rubber are blended with sulfur, carbon black and other additives in a heavy mixer. The mix is milled until it is uniform and rolled out into thin sheets.","inputs":["natural-latex","synthetic-rubber","sulfur","carbon-black"]},{"name":"Cut the pieces","process":"cut","text":"Sheets of raw rubber and a cotton lining are die-cut or hand-cut to the shapes of the upper, the heel and the toe cap. The rubber is soft and sticky at this stage.","inputs":["cotton-fabric"]},{"name":"Build the boot on a form","process":"assemble","text":"The lining is slid over an aluminum boot last, then rubber panels are stretched on and layered by hand. The pieces stick to each other, since the uncured rubber is tacky.","inputs":[]},{"name":"Press on the sole","process":"mold","text":"A separate thick sole, already molded with its tread, is pressed onto the bottom. Seams are rolled flat so there are no gaps for water to find.","inputs":[]},{"name":"Vulcanize in an oven","process":"heat-treat","text":"Boots on their forms go into a hot oven or steam chamber. Heat makes the sulfur form cross-links between the rubber chains, and the soft, sticky rubber turns firm and springy. The process cannot be reversed.","inputs":[]},{"name":"Strip and water test","process":"inspect","text":"Boots are pulled off the lasts, flashing is trimmed, and each one is tested in water to prove it is waterproof before pairs are matched and packed.","inputs":[]}],"facts":["The Duke of Wellington had his shoemaker modify the Hessian boot into a close-fitting calfskin riding boot, which gave Wellington boots their name.","Green Wellington boots were introduced by Hunter Boot in 1955 and came to signal country life in Britain.","Le Chameau says its boots are the only rubber boots each made by a single master bootmaker."],"where":[],"whereNote":null,"sources":[{"title":"Wellington boot","url":"https://en.wikipedia.org/wiki/Wellington_boot"},{"title":"Vulcanization","url":"https://en.wikipedia.org/wiki/Vulcanization"},{"title":"About us (Le Chameau)","url":"https://www.lechameau.com/about-us"},{"title":"How are wellingtons made? (Ardmoor)","url":"https://ardmoor.co.uk/blogs/news/how-are-wellingtons-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rubiks-cube","name":"Rubik's Cube","kind":"product","category":"play","title":"How Rubik's Cubes are made","url":"https://assemblyline.org/make/rubiks-cube","stations":7,"upstream":73,"downstream":0,"depth":10,"dek":"About 500 million Rubik's Cubes had been sold by January 2024, and each has a hidden six-armed core.","answer":"A Rubik's Cube is made of molded plastic pieces that turn around a hidden central core. Factories mold the core, six center caps, twelve edge pieces and eight corner pieces. Colored stickers or tiles are added, the pieces are snapped and screwed or riveted together, and each cube is twisted and checked.","aka":["Magic Cube","Rubik's cube puzzle"],"inputs":["abs-plastic","ink","screw","steel","cardboard-box"],"uses":[],"grounds":["air","water","crude-oil","natural-gas","iron-ore","sulfur","soybeans","rapeseed","clay","titanium-ore","corn","sugarcane","zinc-ore","limestone","dolomite","manganese-ore","coal","rock-salt","quartz","timber","sugar-beet"],"upstreamSlugs":["abs-plastic","ink","screw","steel","cardboard-box","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","water","ethanol","steel-wire","zinc","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","cardboard","adhesive","crude-oil","hydrogen","natural-gas","toluene","iron-ore","sulfur","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","titanium-ore","chlorine","coke","sulfuric-acid","corn","sugarcane","yeast","zinc-ore","limestone","dolomite","silicon","propane","manganese-ore","wood-pulp","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","coal","methanol","rock-salt","molasses","quartz","charcoal","timber","caustic-soda","hydrogen-peroxide","acetone","nitric-acid","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the plastic pieces","process":"mold","text":"Molten plastic is injected into steel molds to make the core, the corner pieces and the edge pieces. Each piece is designed to interlock with its neighbors while still sliding past them.","inputs":["abs-plastic"]},{"name":"Make the center caps","process":"mold","text":"The center of each face is a single square piece fixed to the core. These six squares give the cube its structure, and they never move relative to one another.","inputs":["abs-plastic"]},{"name":"Add the color","process":"print","text":"Each face gets its color from a sticker or a colored plastic tile. Modern cubes use a fixed layout, with white opposite yellow, blue opposite green and orange opposite red.","inputs":["ink"]},{"name":"Fit the pieces around the core","process":"assemble","text":"Workers fit eight corner pieces and twelve edge pieces round the core in the right pattern. Their shapes interlock so the cube holds together without falling apart.","inputs":[]},{"name":"Fix the centers","process":"assemble","text":"Older cubes used a screw that could be tightened or loosened to alter the feel of the turn. Newer official cubes use rivets and cannot be adjusted.","inputs":["screw","steel"]},{"name":"Test the twist","process":"inspect","text":"Each cube is turned by hand or by machine to confirm that every layer rotates freely.","inputs":[]},{"name":"Box it up","process":"package","text":"Cubes are scrambled or set to the solved state, then sealed into cardboard boxes or clear packaging.","inputs":["cardboard-box"]}],"facts":["Erno Rubik's Hungarian patent for the cube was filed on January 30, 1975.","Every legal scramble is solvable, but no move can swap a single pair of pieces or twist a single corner."],"where":[],"whereNote":null,"sources":[{"title":"Rubik's Cube","url":"https://en.wikipedia.org/wiki/Rubik%27s_Cube"},{"title":"Polystyrene","url":"https://en.wikipedia.org/wiki/Polystyrene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rum","name":"Rum","kind":"product","category":"drink","title":"How rum is made","url":"https://assemblyline.org/make/rum","stations":6,"upstream":30,"downstream":0,"depth":6,"dek":"Tropical heat ages rum so fast that about 10 percent evaporates from the cask every year.","answer":"Rum is fermented and distilled sugarcane, usually from molasses, the dark syrup left after sugar is made. Yeast ferments the molasses diluted in water, and the mash is distilled in pot or column stills. Many rums then age in oak barrels in hot climates and are blended for a consistent flavor.","aka":["rhum","rhum agricole","dark rum","white rum"],"inputs":["sugarcane","molasses","yeast","water","lumber","caramel-color","glass-bottle"],"uses":[],"grounds":["sugarcane","water","sugar-beet","timber","silica-sand","limestone","corn","barley","natural-gas","air","rock-salt","trona","crude-oil"],"upstreamSlugs":["sugarcane","molasses","yeast","water","lumber","caramel-color","glass-bottle","sugar-beet","timber","sugar","corn-syrup","malted-barley","ammonia","silica-sand","soda-ash","limestone","polyethylene","lime","corn","corn-starch","barley","natural-gas","air","rock-salt","carbon-dioxide","trona","ethylene","naphtha","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Cut and press the cane","process":"press","text":"Cane is cut near the ground, where the sugar is richest, and milled to squeeze out its juice. Cane is 63% to 73% water and about 12% to 16% sugar.","inputs":["sugarcane"]},{"name":"Ferment the sugars","process":"ferment","text":"Most rum is fermented from molasses, a by-product of sugar making. French-speaking islands such as Martinique often ferment fresh cane juice instead. Yeast and water are added. Slow-working yeasts build up more fruity esters.","inputs":["molasses","yeast","water"]},{"name":"Distill the wash","process":"refine","text":"The fermented liquid is distilled in a pot still for a heavy, flavorful spirit, or in a column still for a lighter one. Most rum comes off a column still.","inputs":[]},{"name":"Age in the tropics","process":"dry","text":"The clear spirit goes into barrels, often used bourbon casks. Heat speeds the aging, so the angels' share, the amount lost to evaporation, runs about 10% a year, against about 2% in Scotland or France.","inputs":["lumber"],"spec":"about 10% lost per year"},{"name":"Blend for consistency","process":"mix","text":"Casks of different ages and stills are blended to the house taste. Light rums are filtered to remove color gained in wood, and caramel may be added to dark rums.","inputs":["caramel-color"]},{"name":"Bottle at strength","process":"fill","text":"Water brings the blend to drinking strength, and it is bottled. Many countries require rum to be aged for at least one year before it can be sold as aged.","inputs":["water","glass-bottle"]}],"facts":["The first recorded rum production, aside from cachaça, took place in Barbados.","The Royal Navy's rum ration was issued at 100 degrees UK proof, 57% alcohol by volume, because that was the only strength that could be tested with gunpowder.","In Brazil, the spirit made from cane juice is called cachaça, not rum.","Rum was so valuable in early New South Wales that convicts could be induced to work for it."],"where":[],"whereNote":null,"sources":[{"title":"Rum","url":"https://en.wikipedia.org/wiki/Rum"},{"title":"Distilled beverage","url":"https://en.wikipedia.org/wiki/Distilled_beverage"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rye","name":"Rye","kind":"raw","category":"farm","title":"How rye is grown","url":"https://assemblyline.org/make/rye","stations":5,"upstream":0,"downstream":1,"depth":0,"dek":"Rye survives snow cover that kills winter wheat. Its leaves make their own antifreeze proteins.","answer":"Farmers sow this cereal in autumn on land too cold or poor for most other grains. It sprouts, sits through the winter, sometimes under snow, and takes off in spring. A combine harvester cuts and threshes it just like wheat. Germany leads world output, and the grain goes into bread, beer, whiskey and animal feed.","aka":["cereal rye","winter rye","Secale cereale"],"inputs":[],"uses":["vodka"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["vodka"],"steps":[{"name":"Sow in autumn","process":"grow","text":"Winter varieties, the most popular kind, go into the ground in autumn and start to grow before the cold arrives. Rye accepts much poorer soil than most cereal grains need.","inputs":[]},{"name":"Wait out the winter","process":"grow","text":"The plants keep growing on warmer days when sunlight lifts them above freezing, even with snow around. Antifreeze proteins in the leaves help them cope. Stalks later reach 1 to 2 meters.","inputs":[]},{"name":"Cut and thresh together","process":"harvest","text":"A combine harvester cuts the plants, threshes and winnows the grain, and drops the straw back on the field. The straw can be baled later or left to feed the soil.","inputs":[]},{"name":"Clean out the ergot","process":"separate","text":"This crop is highly susceptible to ergot, a toxic fungus. Modern grain cleaning and milling have nearly eliminated the disease it causes, though only as long as the checks are kept up.","inputs":[]},{"name":"Store at the elevator","process":"dry","text":"Grain goes to local silos or regional elevators, where lots are combined for storage and shipment. Relatively little of it crosses borders.","inputs":[]}],"facts":["Among cereals, only wheat and rye have the qualities needed to make a loaf of bread.","This hardy grain grows as far north as the Arctic Circle.","Europe's rye likely arrived as a minor admixture in wheat crops, and was only later farmed in its own right."],"where":[{"place":"Germany","share":"25% of world output"}],"whereNote":"2023 world rye production of 12.7 million tonnes, as quoted on Wikipedia. Poland and Russia are the next largest producers.","sources":[{"title":"Rye","url":"https://en.wikipedia.org/wiki/Rye"},{"title":"Rye (Britannica)","url":"https://www.britannica.com/plant/rye"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"safety-pin","name":"Safety pin","kind":"product","category":"hardware","title":"How safety pins are made","url":"https://assemblyline.org/make/safety-pin","stations":9,"upstream":48,"downstream":0,"depth":6,"dek":"The safety pin was invented to pay off a $15 debt, and the inventor sold the patent for $400.","answer":"Automated lines make the whole pin. Spring-steel wire is straightened, cut and ground to a point, then a fourslide machine coils it around a spindle and bends a hook at the blunt end. A cap stamped from sheet steel meets the wire inside that same machine and is crimped on. Pins are usually plated in a rotating tank and finished with wax.","aka":["nappy pin","diaper pin"],"inputs":["steel-wire","sheet-steel","nickel","chromium"],"uses":[],"grounds":["nickel-ore","chromite","limestone","air","water","zinc-ore","sulfur","coal","rock-salt","trona","crude-oil","iron-ore","dolomite","manganese-ore","natural-gas","corn","bauxite","quartz","timber","sugarcane","sugar-beet"],"upstreamSlugs":["steel-wire","sheet-steel","nickel","chromium","steel","zinc","nickel-ore","sulfuric-acid","chromite","coke","soda-ash","limestone","air","water","aluminum","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","sulfur","coal","rock-salt","ammonia","carbon-dioxide","trona","crude-oil","petroleum-coke","alumina","iron-ore","dolomite","silicon","propane","manganese-ore","natural-gas","corn","yeast","bauxite","caustic-soda","quartz","charcoal","timber","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Straighten and cut wire","process":"cut","text":"Coils of high-carbon spring-steel wire feed from spools into a roll straightener, which also chops it to length. Brass and stainless steel are the other common metals.","inputs":["steel-wire"]},{"name":"Grind the point","process":"grind","text":"Cut pieces drop from a hopper and press against grinding wheels, which taper one end to a point and take off nicks and burrs.","inputs":[]},{"name":"Coil around a spindle","process":"press","text":"A custom-tooled fourslide machine, able to move in four directions, picks the wires up on a chain and winds each around a spindle. That coil becomes the spring. A 1902 patent coiled the pin and slipped on a guard in one continuous operation.","inputs":[]},{"name":"Bend the hook","process":"press","text":"The same machine curls the dull end around into a hook, ready to take the cap.","inputs":[]},{"name":"Stamp the cap","process":"stamp","text":"Sheet steel feeds in from the other side. A die first cuts odd flat shapes, then a second stamping raises them into three-dimensional caps.","inputs":["sheet-steel"]},{"name":"Crimp the pair","process":"assemble","text":"Sharpened wire and cap meet inside the machine, and the cap is crimped around the hook. The pin comes out formed with its clasp closed. Pins sold open cost more, since they nest and tangle in small batches.","inputs":[]},{"name":"Plate in a tank","process":"coat","text":"Pins are loaded into perforated baskets. Steel is usually chromed and brass nickel-plated, in an electrically charged tank that rotates to shake the pins for an even coat.","inputs":["nickel","chromium"]},{"name":"Polish and wax","process":"wash","text":"After a water rinse, a chemical bath gives the final polish. A detergent wash and a wax finish follow.","inputs":[]},{"name":"Box the pins","process":"package","text":"Industrial buyers usually get bulk boxes of 10 gross. Stores take polybags or blister packs.","inputs":[]}],"facts":["Walter Hunt made his first safety pin from a piece of brass wire about 8 inches long.","An early ancestor, the fibula brooch, was used by the Mycenaeans between the 14th and 13th centuries BC.","A single factory can turn out over 3 million safety pins in a day."],"where":[],"whereNote":null,"sources":[{"title":"Safety Pin, How Products Are Made, Encyclopedia.com","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/safety-pin"},{"title":"US713727A, Process of manufacturing safety-pins","url":"https://patents.google.com/patent/US713727"},{"title":"Safety pin","url":"https://en.wikipedia.org/wiki/Safety_pin"},{"title":"Wire drawing","url":"https://en.wikipedia.org/wiki/Wire_drawing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sailboat","name":"Sailboat","kind":"product","category":"machines","title":"How sailboats are made","url":"https://assemblyline.org/make/sailboat","stations":11,"upstream":69,"downstream":0,"depth":8,"dek":"A production sailboat gets its whole interior before its deck, which then drops on like a lid.","answer":"Most production sailboats are fiberglass hulls laminated inside a polished mold, starting with a skin of gel coat. A stiffening grid goes in, then engine, plumbing and prefabricated cabins. The separately molded deck is bonded and bolted on top, a cast keel is bolted beneath, and the boat is water tested. Mast and sails often go on at the dealer.","aka":["sailing yacht","sailing boat"],"inputs":["polyester","fiberglass","adhesive","lead","pig-iron","aluminum","wire-rope"],"uses":[],"grounds":["silica-sand","limestone","water","lead-ore","iron-ore","air","crude-oil","coal","rock-salt","trona","zinc-ore","bauxite","natural-gas","corn","sulfur","dolomite","manganese-ore","sugarcane","sugar-beet","quartz","timber"],"upstreamSlugs":["polyester","fiberglass","adhesive","lead","pig-iron","aluminum","wire-rope","pet-plastic","silica-sand","limestone","soda-ash","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","lead-ore","coke","zinc","iron-ore","air","crude-oil","coal","petroleum-coke","alumina","steel-wire","p-xylene","ethylene","ethylene-glycol","rock-salt","ammonia","carbon-dioxide","lime","trona","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","hydrogen","zinc-ore","bauxite","steel","naphtha","natural-gas","oxygen","corn","yeast","sulfur","benzene","magnesium","steel-scrap","manganese","argon","molasses","toluene","dolomite","silicon","propane","manganese-ore","sugarcane","sugar-beet","quartz","charcoal","timber"],"downstreamSlugs":[],"steps":[{"name":"Spray the gel coat","process":"coat","text":"Layers of gel coat are sprayed into a clean, highly polished mold to form the outer skin. Dufour's molds come in two parts and sit on rollers, so workers can rotate them in place.","inputs":["polyester"]},{"name":"Laminate the shell","process":"laminate","text":"Glass cloth and core materials go in by hand and are soaked with resin, layer by layer. Hunter's hull is solid below the waterline and balsa-cored above it. Vacuum infusion and injection are the alternatives.","inputs":["fiberglass","polyester"]},{"name":"Thicken the loaded areas","process":"laminate","text":"Workers add extra laminate at the chainplates and around the keel, where the rig and ballast pull hardest.","inputs":["fiberglass"]},{"name":"Bond in the grid","process":"assemble","text":"A molded fiberglass grid is chemically bonded into the fresh hull to give it stiffness. Hunter builds interior units onto this grid first, then lowers the lot in together.","inputs":["adhesive"]},{"name":"Infuse the top half","process":"mold","text":"Dry glass mats go into a separate mold under a plastic cover. Air is sucked out at one end and resin drawn in at the other, which pulls it through the mats and leaves a stiff, thin deck.","inputs":["fiberglass","polyester"]},{"name":"Install the systems","process":"assemble","text":"The empty hull rolls to the fitting hall. Engine, tanks and steering usually go first, then plumbing and wiring.","inputs":[]},{"name":"Drop in the cabins","process":"assemble","text":"Series builders assemble bathrooms, cabins and saloons outside the boat, already wired. Each module is hauled in and glued, screwed or laminated into place.","inputs":["adhesive"]},{"name":"Marry hull and deck","process":"assemble","text":"Once the interior is in, the deck goes on top, closing the boat. The joint is usually high-strength glue plus screws or bolts.","inputs":["adhesive"]},{"name":"Bolt on the keel","process":"assemble","text":"A keel of cast iron or lead is lined up exactly with the centerline and fixed to the underside with keel bolts. Cast iron is heavy and cheap, while lead is denser.","inputs":["lead","pig-iron"]},{"name":"Test for leaks","process":"inspect","text":"In a pool or a station like an oversized carwash, the boat floats for the first time and takes hours of artificial rain, so inspectors can find leaks at hatches and portholes.","inputs":[]},{"name":"Rig the mast","process":"assemble","text":"Dealers at big brands often step the aluminum mast, attach the wire rigging, and install sails of synthetic cloth such as Dacron.","inputs":["aluminum","wire-rope","polyester"]}],"facts":["Monohull sailboats generally rely on ballast for stability, and in racing boats the ballast can be a large part of the weight.","Multihull sailboats rely on the geometry and broad stance of their hulls for stability and carry no ballast.","A prefabricated bathroom can be fitted into a yacht in just a few hours if the installation goes well, according to the builder Hanse."],"where":[],"whereNote":null,"sources":[{"title":"Sailboat","url":"https://en.wikipedia.org/wiki/Sailboat"},{"title":"How sailing yachts are made, Hanse Yachts","url":"https://hanseyachts.com/us/blog/how-are-sailboats-made/"},{"title":"How It's Made: Fiberglass Hulls, Cruising World","url":"https://www.cruisingworld.com/how-its-made-fiberglass-hulls/"},{"title":"Hunter Factory Blends Old and New Technology, Practical Sailor","url":"https://www.practical-sailor.com/sailboat-reviews/hunter-factory-blends-old-and-new-technology/"},{"title":"Learn How BENETEAU Builds Boats","url":"https://www.beneteau.com/en-us/newsroom-news/learn-how-beneteau-builds-boats"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sake","name":"Sake","kind":"product","category":"drink","title":"How sake is made","url":"https://assemblyline.org/make/sake","stations":8,"upstream":26,"downstream":0,"depth":6,"dek":"In a sake tank, a mold turns starch to sugar while yeast turns sugar to alcohol, all at the same time.","answer":"Sake is brewed from rice that has been polished to strip off the outer layers. The rice is steamed, and some of it is seeded with koji mold, which turns starch into sugar. Yeast, rice, koji and water are then added to a tank in three steps, so conversion and fermentation run together. The mash is pressed, pasteurized and matured.","aka":["nihonshu","japanese rice wine","seishu"],"inputs":["rice","water","yeast","koji","glass-bottle"],"uses":[],"grounds":["rice","water","soybeans","wheat","silica-sand","limestone","sugarcane","sugar-beet","rock-salt","trona","natural-gas","air","corn","crude-oil"],"upstreamSlugs":["rice","water","yeast","koji","glass-bottle","molasses","soybeans","wheat","silica-sand","soda-ash","limestone","polyethylene","sugarcane","sugar-beet","rock-salt","ammonia","carbon-dioxide","lime","trona","ethylene","natural-gas","air","corn","naphtha","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Polish away the husk","process":"grind","text":"Sake rice is milled to remove the outer layers, which carry fat and protein that would cause off-flavors. Only the starchy core stays. A polish of 70% means 30% of each grain has been ground away.","inputs":["rice"],"spec":"two to three days to polish below half size"},{"name":"Wash and steam rice","process":"cook","text":"The polished rice is washed, soaked and steamed. Water quality matters throughout, since it makes up most of the finished sake.","inputs":["water"]},{"name":"Grow the koji mold","process":"grow","text":"Spores of the fungus Aspergillus oryzae are scattered over part of the steamed rice. In a warm, moist room the mold grows and releases enzymes that cut starch into glucose and maltose.","inputs":[]},{"name":"Raise a yeast starter","process":"ferment","text":"Steamed rice, water, koji and yeast are mixed into a small starter called the shubo. It gives the yeast a head start before it is added to the main tank.","inputs":["yeast","koji"]},{"name":"Add rice in three steps","process":"ferment","text":"On the first day the starter goes into the tank with steamed rice, koji and water. A rest day follows, then a second addition on day three and a third on day four. Because the enzymes make sugar as the yeast eats it, sake can reach a higher alcohol content than beer.","inputs":["rice","water","koji"],"spec":"about two weeks of fermentation"},{"name":"Press out the lees","process":"press","text":"Fermented mash, called moromi, is pressed to separate the clear liquid from the solid rice lees. Cloudy leftover can be sold separately.","inputs":[]},{"name":"Heat to stabilize","process":"pasteurize","text":"The sake is pasteurized and filtered. Heat kills remaining microbes and stops enzymes from changing it further.","inputs":[]},{"name":"Mature and bottle","process":"dry","text":"Sake benefits from a period of cold storage before it is diluted with water to a typical strength and bottled. Undiluted sake is 18 to 20% alcohol.","inputs":["water","glass-bottle"],"spec":"nine to twelve months"}],"facts":["The most polished sake on record, Reikyo Crystal 0, has a polishing ratio of 0.85% or less.","There are at least 123 types of sake rice in Japan.","Premium sake is about 25% of production, and non-premium sake is 75%.","Sake is often called rice wine, but its brewing is closer to beer than to wine."],"where":[],"whereNote":null,"sources":[{"title":"Sake","url":"https://en.wikipedia.org/wiki/Sake"},{"title":"Brewing","url":"https://en.wikipedia.org/wiki/Brewing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"salami","name":"Salami","kind":"product","category":"food","title":"How salami is made","url":"https://assemblyline.org/make/salami","stations":6,"upstream":12,"downstream":0,"depth":3,"dek":"Classic salami is never cooked. Friendly bacteria sour the meat and drying does the rest.","answer":"Pork or beef is coarsely ground and mixed with salt, sugar, spices and a starter culture of lactic acid bacteria. The mixture is stuffed into casings and hung in a warm, humid room for a day or three, so the bacteria make acid. Then it hangs in a cool, humid room to dry slowly until it is firm.","aka":["salame","dry sausage","cured sausage"],"inputs":["pigs","table-salt","sugar","sausage-casing"],"uses":[],"grounds":["pigs","rock-salt","seawater","sugarcane","sugar-beet","water","cattle-hide","limestone"],"upstreamSlugs":["pigs","table-salt","sugar","sausage-casing","rock-salt","seawater","sugarcane","sugar-beet","water","lime","cattle-hide","limestone"],"downstreamSlugs":[],"steps":[{"name":"Grind coarse","process":"crush","text":"Raw pork or beef is ground coarsely, so you can still see fat and lean in the slice.","inputs":["pigs"]},{"name":"Mix with salt and culture","process":"mix","text":"Salt, sugar, spices and pepper go in. So does a starter culture of lactic acid bacteria, which replaced the wine that early makers used to encourage friendly microbes.","inputs":["table-salt","sugar"]},{"name":"Stuff the casing","process":"fill","text":"The mixture is stuffed into natural or cellulose casings of the size the style calls for. A casing is chosen to match the drying speed, since the climate and casing size set how long curing takes.","inputs":["sausage-casing"]},{"name":"Ferment warm and damp","process":"ferment","text":"The salami hangs in a warm, humid room. Bacteria feed on added sugar and make lactic acid. The acid lowers the pH and coagulates the proteins, making the meat inhospitable to harmful bacteria and giving the tang that sets salami apart from plain dried pork.","inputs":[],"spec":"1 to 3 days"},{"name":"Dry slowly in the cool","process":"dry","text":"After fermentation the sausage is moved to a cool, humid room to dry. The casing turns from water-permeable to reasonably airtight. A white coat of mold or flour protects the meat from light and keeps fat from going rancid.","inputs":[]},{"name":"Inspect and pack","process":"package","text":"Finished salami is checked, then sold whole or sliced. Although it is uncooked, it is not raw, because it has been cured.","inputs":[]}],"facts":["Some recipes warm the salami to about 40 °C to speed fermentation and drying, and higher heat stops fermentation once the right pH is reached.","Makers often treat the casings with an edible Penicillium mold, which adds flavor and helps drying.","Hungarian salami is intensively smoked and then its surface is inoculated with mold starters."],"where":[],"whereNote":null,"sources":[{"title":"Salami","url":"https://en.wikipedia.org/wiki/Salami"},{"title":"Sausage","url":"https://en.wikipedia.org/wiki/Sausage"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sandwich-cookie","name":"Sandwich cookie","kind":"product","category":"food","title":"How sandwich cookies are made","url":"https://assemblyline.org/make/sandwich-cookie","stations":7,"upstream":34,"downstream":0,"depth":9,"dek":"A sandwich cookie is two baked wafers stuck together by a cream filling squirted between them.","answer":"At the Oreo plant in Montreal, machines do all the work. A giant vessel blends flour, sugar and two kinds of cocoa into dough. A molding machine cuts rounds and imprints the pattern, and an oven bakes them. A fan cools the wafers, which are flipped so that another machine can put filling on half of them and press the other half on top before wrapping.","aka":["sandwich biscuit","cream cookie","Oreo","creme-filled cookie"],"inputs":["flour","sugar","vegetable-oil","cocoa-powder","palm-oil"],"uses":[],"grounds":["wheat","water","sugarcane","sugar-beet","soybeans","rapeseed","clay","cocoa-beans","oil-palm-fruit","air","limestone","crude-oil","corn","natural-gas"],"upstreamSlugs":["flour","sugar","vegetable-oil","cocoa-powder","palm-oil","wheat","water","vitamin-c","sugarcane","sugar-beet","lime","soybeans","rapeseed","hexane","clay","cocoa-beans","oil-palm-fruit","corn-starch","hydrogen","air","plastic-bottle","limestone","crude-oil","corn","natural-gas","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","yeast","molasses"],"downstreamSlugs":[],"steps":[{"name":"Blend the dough","process":"mix","text":"Flour, sugar, fat and two kinds of cocoa go into a mixing vessel in a batch that fills a 2,000-lb tub, then blend into a single dough.","inputs":["flour","sugar","vegetable-oil","cocoa-powder"]},{"name":"Cut and imprint rounds","process":"mold","text":"A molding machine cuts the dough into circles and presses the brand's pattern into the face of each one in the same pass.","inputs":[]},{"name":"Bake the wafers","process":"bake","text":"The rounds travel through an oven and come out as crisp dark wafers.","inputs":[]},{"name":"Cool and flip","process":"chill","text":"Fans cool the wafers, then a flipping step turns half of them over so their flat sides face up for the filling.","inputs":[]},{"name":"Whip the filling","process":"mix","text":"Sugar and fat are whipped smooth in a separate mixer and pumped to the sandwiching line.","inputs":["sugar","palm-oil"]},{"name":"Deposit and sandwich","process":"assemble","text":"A machine dispenses a measured dollop of cream onto half the wafers, and the other half are pressed on top.","inputs":[]},{"name":"Stack and wrap","process":"package","text":"Finished sandwiches are stacked in rows and sealed in wrapping for shipment to retailers.","inputs":[]}],"facts":["By 2017, more than 40 billion Oreo cookies were being produced annually in 18 countries.","The Oreo biscuit was first produced by Nabisco in early 1912 at its Chelsea factory in New York City.","A 2022 study in Physics of Fluids found the cream filling always sticks to one wafer when an Oreo is twisted apart, however fast the twist."],"where":[],"whereNote":null,"sources":[{"title":"Mashed: This is how Oreos are actually made","url":"https://www.mashed.com/590635/this-is-how-oreos-are-actually-made"},{"title":"Sandwich cookie","url":"https://en.wikipedia.org/wiki/Sandwich_cookie"},{"title":"Oreo","url":"https://en.wikipedia.org/wiki/Oreo"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sanitary-pad","name":"Sanitary pad","kind":"product","category":"body-health","title":"How sanitary pads are made","url":"https://assemblyline.org/make/sanitary-pad","stations":7,"upstream":38,"downstream":0,"depth":8,"dek":"A disposable pad is a sandwich, and its middle layer holds a powder that turns to gel when wet.","answer":"A disposable menstrual pad is layered: an absorbent core between a soft nonwoven top sheet and a liquid-proof polyethylene film backing. The core is ground fluff pulp wrapped in tissue, often with superabsorbent polymer powder that gels when wet. Hot melt seals the layers, a glue strip and release paper go on the back, and the strip is cut and wrapped.","aka":["menstrual pad","sanitary napkin","maxi pad"],"inputs":["wood-pulp","superabsorbent-polymer","paper","polypropylene","polyethylene","adhesive"],"uses":[],"grounds":["timber","water","kaolin","limestone","rock-salt","air","crude-oil","natural-gas","sulfur","coal"],"upstreamSlugs":["wood-pulp","superabsorbent-polymer","paper","polypropylene","polyethylene","adhesive","timber","caustic-soda","water","lime","oxygen","hydrogen-peroxide","acrylic-acid","kaolin","limestone","propylene","ethylene","acrylic","epoxy","polyurethane","paraffin-wax","rock-salt","air","hydrogen","naphtha","crude-oil","natural-gas","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","sulfur","benzene","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Grind the pulp","process":"grind","text":"Sheets of fluff pulp, made from wood, are ground up into loose fibers. The fluffed fiber is what gives the core its bulk and wicking.","inputs":["wood-pulp"]},{"name":"Form the absorbent mat","process":"press","text":"The fibers are laid into a mat, with superabsorbent polymer added as an extra absorbent. Tissue is spread above and below it to hold the mat together.","inputs":["superabsorbent-polymer","paper"]},{"name":"Lay the top sheet","process":"laminate","text":"A thermally bonded nonwoven fabric covers the core on the side that touches the body. It passes fluid quickly to the center and stays soft.","inputs":["polypropylene"]},{"name":"Wrap in film","process":"laminate","text":"A very thin polyethylene film goes on the outer side to stop leaks.","inputs":["polyethylene"]},{"name":"Seal and emboss","process":"press","text":"Hot melt adhesive and embossing seal the layers together around the edge of each pad.","inputs":["adhesive"]},{"name":"Apply the glue strip","process":"coat","text":"A pressure-sensitive hot melt is laid on the outside of the backing so the pad stays on the underwear, and release paper covers it until use.","inputs":["adhesive","paper"]},{"name":"Cut and wrap","process":"cut","text":"The layered strip is cut into pad shapes and each pad is folded and wrapped for sale.","inputs":[]}],"facts":["Disposable pads first appeared commercially around 1880 with the Southall sisters' pad.","Johnson & Johnson's Lister's Towels, from 1888, were the first commercial American disposable napkins.","Early pads were up to two centimeters thick, and leaks were a major problem."],"where":[],"whereNote":null,"sources":[{"title":"Sanitary napkin","url":"https://en.wikipedia.org/wiki/Sanitary_napkin"},{"title":"Fluff pulp","url":"https://en.wikipedia.org/wiki/Fluff_pulp"},{"title":"Sanitary napkin manufacturing (Textile Learner)","url":"https://textilelearner.net/?p=1979"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"satellite","name":"Satellite","kind":"product","category":"machines","title":"How satellites are made","url":"https://assemblyline.org/make/satellite","stations":11,"upstream":94,"downstream":0,"depth":9,"dek":"During a satellite's shake test, a white blanket catches anything that drops, and someone has to explain every stray bolt.","answer":"Most of a satellite is built as separate subassemblies, each part tested before installation, then joined by miles of cabling into one spacecraft. The whole thing then visits a vacuum chamber, a shaker table, an acoustic chamber and a radio test room. Only at the launch site does it receive propellant and go inside the nose of the rocket.","aka":["artificial satellite","communications satellite","spacecraft"],"inputs":["aluminum","carbon-fiber","printed-circuit-board","microchip","camera-sensor","copper-wire","solar-panel","lithium-ion-cell"],"uses":[],"grounds":["crude-oil","coal","air","bauxite","water","natural-gas","copper-ore","silica-sand","limestone","quartz","tin-ore","gold-ore","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","iron-ore","rock-salt","sulfur","trona","lead-ore","silver-ore","zinc-ore","timber","dolomite","corn","sugarcane","sugar-beet"],"upstreamSlugs":["aluminum","carbon-fiber","printed-circuit-board","microchip","camera-sensor","copper-wire","solar-panel","lithium-ion-cell","crude-oil","coal","petroleum-coke","alumina","propylene","ammonia","air","copper","fiberglass","epoxy","photoresist","solder","silicon-wafer","oxygen","tin","gold","glass","solar-cell","plastic","silicone","lithium-carbonate","cobalt","nickel","manganese","synthetic-graphite","polyethylene","steel","bauxite","caustic-soda","lime","water","naphtha","natural-gas","copper-ore","sulfuric-acid","silica-sand","limestone","soda-ash","phenol","acetone","chlorine","phenolic-resin","lead","silver","polysilicon","quartz","argon","tin-ore","coke","gold-ore","zinc","ethylene","silicon","methanol","hydrochloric-acid","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","iron-ore","pig-iron","magnesium","steel-scrap","rock-salt","hydrogen","sulfur","carbon-dioxide","trona","benzene","formaldehyde","lead-ore","silver-ore","zinc-ore","trichlorosilane","nitrogen","charcoal","timber","dolomite","propane","corn","yeast","toluene","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Form the structure","process":"laminate","text":"Beams and panels make up the frame that carries everything else. Aluminum is favored for being light and fairly cheap, and the Spacebus design from Thales Alenia uses carbon fiber around a composite honeycomb.","inputs":["aluminum","carbon-fiber"]},{"name":"Build the subassemblies","process":"assemble","text":"Equipment boxes are built in-house or by subcontractors, each packed with hundreds of parts. Every component is tested to prove it will perform in space, even if it is headed into a subassembly. Flight computers must cope with space, run largely on their own and tolerate faults.","inputs":["printed-circuit-board","microchip"]},{"name":"Outfit the payload","process":"assemble","text":"On some designs the payload is developed apart from the bus and fills its own panels. Transponders go on communications satellites, and observation satellites carry cameras or radar. The finished panels travel to the integration site to join the bus.","inputs":["camera-sensor"]},{"name":"Join with cable and waveguide","process":"assemble","text":"Subassemblies are brought together into a single system. Hundreds of units are linked by miles of electrical wiring plus radio frequency waveguides or coaxial cable.","inputs":["copper-wire"]},{"name":"Fit power and heat control","process":"assemble","text":"External panels take the solar arrays and engine, and batteries store the power. Radiators, insulation and heaters hold the equipment at working temperatures, since in space heat moves mainly by radiation and conduction.","inputs":["solar-panel","lithium-ion-cell"]},{"name":"Weigh and balance","process":"inspect","text":"In clean rooms, crews check the craft and unfold its solar arrays in a deployment test. A dedicated rig measures its center of gravity and moments of inertia against the design.","inputs":[]},{"name":"Run the thermal vacuum","process":"inspect","text":"A large chamber lined with temperature-controlled panels has its air pumped out. Heat flow between zones inside the craft cannot be reproduced in normal air, so this test matters. The UK's chamber is seven meters across and 12 meters long.","inputs":[]},{"name":"Shake it","process":"inspect","text":"Mounted on a shaker table, the craft is vibrated to mimic launch, which lasts roughly 30 minutes. A blanket laid underneath catches tie wraps, bolts or screws, and the team must trace where each one came from.","inputs":[],"spec":"five to 200 Hz in three axes at one UK facility"},{"name":"Blast it with sound","process":"inspect","text":"Huge speakers in an acoustic chamber recreate the noise inside a rocket during the first seconds of launch. The speakers are close cousins of those used at rock concerts.","inputs":[],"spec":"typically 147 adjusted decibels at one UK facility"},{"name":"Check radio emissions","process":"inspect","text":"After the mechanical tests come radio frequency checks in an anechoic chamber shielded from outside interference. Near-field scanners can also measure how the antennas perform.","inputs":[]},{"name":"Ship and fuel","process":"fill","text":"The craft is airlifted in a shipping container to the launch base and retested for transit damage. Crews in protective gear then load propellant, a hazardous job, and any contamination could spoil thruster performance. Finally it is sealed inside the rocket's fairing.","inputs":[]}],"facts":["Intelsat says only one commercially available plane, the Antonov-124, is big enough to carry its satellite shipping container.","Climbing to geostationary orbit burns about two-thirds of a satellite's propellant, leaving a third to last its 15 or so years of service.","Noise in the UK's National Satellite Test Facility acoustic chamber typically reaches 147 adjusted decibels."],"where":[],"whereNote":null,"sources":[{"title":"The Making of an Intelsat Satellite","url":"https://cyprusshippingnews.com/2021/02/08/the-making-of-an-intelsat-satellite/"},{"title":"National Satellite Test Facility","url":"https://ukri.org/what-we-do/browse-our-areas-of-investment-and-support/national-satellite-test-facility"},{"title":"Spacebus","url":"https://en.wikipedia.org/wiki/Spacebus"},{"title":"Spacecraft design","url":"https://en.wikipedia.org/wiki/Spacecraft_design"},{"title":"Satellite","url":"https://en.wikipedia.org/wiki/Satellite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sauerkraut","name":"Sauerkraut","kind":"product","category":"food","title":"How sauerkraut is made","url":"https://assemblyline.org/make/sauerkraut","stations":6,"upstream":21,"downstream":0,"depth":7,"dek":"Sauerkraut is just cabbage and salt. Three waves of bacteria take turns souring it.","answer":"Cabbage is shredded fine, layered with salt and packed down until its own juice covers it. Lactic acid bacteria already on the leaves ferment its sugars in three overlapping phases, dropping the pH until the cabbage is sour and safe. Fully cured sauerkraut keeps for months in a sealed container at 15 °C or below.","aka":["sour cabbage","fermented cabbage","choucroute"],"inputs":["cabbage","table-salt","glass-jar"],"uses":[],"grounds":["cabbage","rock-salt","seawater","silica-sand","limestone","water","trona","natural-gas","air","corn","sugarcane","sugar-beet"],"upstreamSlugs":["cabbage","table-salt","glass-jar","rock-salt","seawater","glass","silica-sand","soda-ash","limestone","water","ammonia","carbon-dioxide","lime","trona","natural-gas","air","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Shred the heads","process":"cut","text":"White cabbage is cut into fine shreds, which exposes lots of surface and lets the juice run once salt hits it.","inputs":["cabbage"]},{"name":"Layer with salt","process":"mix","text":"Salt is spread between layers of cabbage. It draws out water and creates a brine, and the salt favors the right bacteria over spoilage microbes.","inputs":["table-salt"]},{"name":"Pack under brine","process":"press","text":"The salted shreds are packed down so the brine rises over them and keeps out air. Fermentation works best with no oxygen.","inputs":[]},{"name":"Hand over to three bacteria crews","process":"ferment","text":"Bacteria that live on raw cabbage leaves begin turning sugars into acid. In the first phase some bacteria start the souring. Then Leuconostoc takes over once acid levels get too high for the first group. Finally Lactobacillus species finish the sugars and push the pH lower.","inputs":[]},{"name":"Cure until sour","process":"ferment","text":"The kraut keeps fermenting until the acid is high enough that botulism bacteria cannot grow. If it runs too warm, yeasts can leave it soft and poor in flavor.","inputs":[]},{"name":"Pack for sale","process":"fill","text":"Finished kraut goes into airtight containers. Refrigeration or pasteurization is optional but lengthens its storage life.","inputs":["glass-jar"],"spec":"keeps for months at 15 °C or below"}],"facts":["Captain James Cook carried sauerkraut on his voyages to help prevent scurvy.","During World War I some American makers relabeled sauerkraut as liberty cabbage to avoid its German name."],"where":[],"whereNote":null,"sources":[{"title":"Sauerkraut","url":"https://en.wikipedia.org/wiki/Sauerkraut"},{"title":"Pickling","url":"https://en.wikipedia.org/wiki/Pickling"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sausage","name":"Sausage","kind":"product","category":"food","title":"How sausages are made","url":"https://assemblyline.org/make/sausage","stations":6,"upstream":6,"downstream":1,"depth":3,"dek":"Sausage is trimmed meat and fat, salted, spiced and stuffed into a tube that often used to be an intestine.","answer":"Meat and fat are cut or ground, mixed with salt, seasoning and sometimes a starch filler, then stuffed into a casing. Casings are traditionally cleaned animal intestines, though factories often use collagen, cellulose or plastic. The links are then cooked, cured, smoked, dried or frozen, depending on the style.","aka":["bangers","links","bratwurst"],"inputs":["pigs","table-salt","sausage-casing"],"uses":["frozen-pizza"],"grounds":["pigs","rock-salt","seawater","cattle-hide"],"upstreamSlugs":["pigs","table-salt","sausage-casing","rock-salt","seawater","cattle-hide"],"downstreamSlugs":["frozen-pizza"],"steps":[{"name":"Trim and grind the meat","process":"cut","text":"Pork, beef or poultry is cut into pieces or ground, with fat added to reach the planned lean-to-fat ratio. Premium sausage uses choice cuts, while cheap sausage may use meat recovered mechanically from carcasses.","inputs":["pigs"]},{"name":"Mix in salt and seasoning","process":"mix","text":"Salt and spices go into the ground meat. British-style sausages often add breadcrumbs or grain as filler, up to about 30 percent of the ingredients, which soaks up moisture and fat as the sausage cooks.","inputs":["table-salt"]},{"name":"Stuff into casings","process":"fill","text":"The mixture is pushed into a casing, which gives the sausage its shape. Natural casings come from the cleaned submucosa of pig or sheep intestines. Industrial lines often use collagen or cellulose casings made by extrusion.","inputs":["sausage-casing"]},{"name":"Twist into links","process":"cut","text":"The filled tube is twisted or tied at regular intervals into separate links.","inputs":[]},{"name":"Cook, cure or smoke","process":"cook","text":"Some links stay raw and others are cooked. Curing, drying and smoking preserve sausage, and some cured or smoked styles keep without refrigeration.","inputs":[]},{"name":"Chill and pack","process":"package","text":"Most fresh sausages must stay refrigerated or frozen until cooked, so they are chilled and packed straight away.","inputs":[]}],"facts":["An Akkadian cuneiform tablet records a dish of intestine casings filled with some sort of forcemeat.","Natural casings are sold by the hank, a bundle of casing strands that measures 91 meters.","The meat percentage on a British sausage label can exceed 100 percent when the weight of meat before cooking is counted."],"where":[],"whereNote":null,"sources":[{"title":"Sausage","url":"https://en.wikipedia.org/wiki/Sausage"},{"title":"Casing (sausage)","url":"https://en.wikipedia.org/wiki/Casing_(sausage)"},{"title":"Small-scale sausage production, FAO","url":"https://www.fao.org/3/x6556e/X6556E00.htm"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sausage-casing","name":"Sausage casing","kind":"material","category":"food","title":"How sausage casings are made","url":"https://assemblyline.org/make/sausage-casing","stations":8,"upstream":5,"downstream":4,"depth":2,"dek":"Natural sausage casing is the inner lining of an animal's small intestine, sold by the hank.","answer":"Natural casings are the submucosa of a meat animal's small intestine, mostly collagen. Cleaning plants strip off the fat and contents, crush the gut between rollers and slime away every other layer. The tube that remains is inflated to grade its diameter, packed in salt and sold in hanks. Artificial casings are extruded from collagen or made from cellulose.","aka":["sausage skin","natural casing","hog casing"],"inputs":["pigs","table-salt","cattle-hide"],"uses":["hot-dog","sausage","salami"],"grounds":["pigs","cattle-hide","rock-salt","seawater"],"upstreamSlugs":["pigs","table-salt","cattle-hide","rock-salt","seawater"],"downstreamSlugs":["hot-dog","sausage","salami","frozen-pizza"],"steps":[{"name":"Pull the runners","process":"harvest","text":"At the slaughter plant, uncleaned intestines called runners are pulled from the animal. A pig's small intestine averages 15 to 20 meters long. In Western European and Chinese cuisine, most casings come from pigs.","inputs":["pigs"]},{"name":"Strip fat and contents","process":"separate","text":"Workers or machines remove the fat and mesentery, a step called running. The contents are then pushed out, which is called stripping.","inputs":[]},{"name":"Crush between rollers","process":"crush","text":"The intestine passes through a mucous crusher, whose rollers break up its inner lining so it will come away.","inputs":[]},{"name":"Slime off the layers","process":"wash","text":"A second set of rollers scrapes away the mucosa, both muscle layers and the outer serosa. Pig rounds keep only the strong, collagen-rich submucosa. Older plants got the same result by fermenting the guts and sliming by hand.","inputs":[]},{"name":"Inflate and grade","process":"inspect","text":"Air or water blows up each length so its diameter can be measured. Pig grades run from narrow, at 28 mm and under, to extra wide, at 42 mm and over.","inputs":[]},{"name":"Pack in salt","process":"dry","text":"Graded casings are salted heavily, about 40 percent salt, and stored that way until used. Sausage makers soak them to desalt them first.","inputs":["table-salt"],"spec":"40% salt"},{"name":"Bundle into hanks","process":"package","text":"Pig rounds sell in hanks of 100 yards, usually 15 to 20 pieces of roughly equal length.","inputs":[],"spec":"91.4 m per hank"},{"name":"Or extrude collagen tubes","process":"extrude","text":"Artificial casings are made from collagen, often from cattle skin, shaped by continuous extrusion. Cellulose and plastic casings also exist, and they deliver a uniform diameter.","inputs":["cattle-hide"]}],"facts":["Artificial casings were introduced in the early 20th century.","Sheep, goat, cattle and sometimes horse intestines are also used where pork is not."],"where":[],"whereNote":null,"sources":[{"title":"Small-scale sausage production: Sausage casings, FAO","url":"https://www.fao.org/3/x6556e/x6556e03.htm"},{"title":"Sausage casing","url":"https://en.wikipedia.org/wiki/Sausage_casing"},{"title":"Collagen","url":"https://en.wikipedia.org/wiki/Collagen"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"saw-blade","name":"Saw blade","kind":"product","category":"hardware","title":"How saw blades are made","url":"https://assemblyline.org/make/saw-blade","stations":7,"upstream":41,"downstream":0,"depth":6,"dek":"Saw blades get dished on purpose and then ground flat, so the internal stress stays and the wobble goes.","answer":"A carbide-tipped circular saw blade begins as a laser-cut steel disc. Heat treatment hardens and toughens it, tensioning locks in a stress that fights vibration, and grinding brings it back flat before it is balanced. Carbide tips are then brazed to the rim and sharpened by CNC grinders with diamond wheels. Small plain-steel blades can instead be punched from strip in one press.","aka":["circular saw blade","carbide blade"],"inputs":["sheet-steel","tungsten-carbide"],"uses":[],"grounds":["zinc-ore","air","tungsten-ore","crude-oil","water","cobalt-ore","iron-ore","limestone","dolomite","manganese-ore","natural-gas","sulfur","coal","quartz","timber","bauxite","rock-salt"],"upstreamSlugs":["sheet-steel","tungsten-carbide","steel","zinc","tungsten","carbon-black","cobalt","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","tungsten-ore","hydrogen","crude-oil","water","cobalt-ore","aluminum","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","sulfur","coal","petroleum-coke","alumina","quartz","charcoal","timber","bauxite","caustic-soda","rock-salt"],"downstreamSlugs":[],"steps":[{"name":"Laser out the disc","process":"cut","text":"A high-powered CO2 laser follows a CAD path through sheet steel, usually a high-carbon, high-chrome grade. One Irwin plant cuts alternating areas of the blank so heat cannot build up in any one spot.","inputs":["sheet-steel"]},{"name":"Harden and temper","process":"heat-treat","text":"Discs go into the heat at 860 °C to 1100 °C, depending on the steel, then get quenched. Clamped in packs, they warm slowly again to 350 °C to 560 °C, which gives up some hardness for toughness.","inputs":[],"spec":"860 °C to 1100 °C"},{"name":"Tension the body","process":"press","text":"Tensioning leaves a slight dish across the diameter and builds in a stress that resists vibration during a cut.","inputs":[]},{"name":"Grind it flat","process":"grind","text":"The dish itself is unwanted, so a surface grinder takes the disc back to flat and to its required thickness. The internal tension survives.","inputs":[]},{"name":"Balance by hand","process":"inspect","text":"At the Irwin plant, skilled machinists measure each disc, grind it on a bench grinder and check it again. Typical 10-inch blades are held to within 1 gram across the diameter. Freud does this step with an automated system.","inputs":[],"spec":"within 1 gram"},{"name":"Braze on carbide tips","process":"weld","text":"Tungsten carbide tips are sorted by machine and brazed to the rim automatically. Freud's brazing alloy puts copper between layers of silver, so the joint can take hard knocks.","inputs":["tungsten-carbide"]},{"name":"Sharpen with diamond","process":"grind","text":"Computer-controlled multi-axis grinders with diamond wheels shape every tip. On the Irwin line this happens inside an enclosed cabinet.","inputs":[]}],"facts":["Copper pull saws turned up in an Egyptian tomb from Djer's reign, in the 31st century BC.","The Irwin plant visited by Canadian Contractor made hundreds of thousands of blades a year on three shifts of only 10 people each.","One patent describes a press tool that turns out a virtually finished small circular blade with every stroke, leaving only the tooth tops to grind."],"where":[],"whereNote":null,"sources":[{"title":"Saw","url":"https://en.wikipedia.org/wiki/Saw"},{"title":"How Carbide Saw Blades Are Made, Canadian Contractor","url":"https://www.canadiancontractor.ca/canadian-contractor/how-carbide-saw-blades-are-made/2689/"},{"title":"Circular Saw Manufacturing Process, Harris Sawing Equipment","url":"https://www.harrissawing.com/circular-saw-manufacturing-process/"},{"title":"Circular Saw Blades, Freud","url":"https://www.freudtools.com/gb/en/products/circular-saw-blades/"},{"title":"US4325272A: Method of making saw blades","url":"https://patents.google.com/patent/US4325272A/en"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"saxophone","name":"Saxophone","kind":"product","category":"play","title":"How saxophones are made","url":"https://assemblyline.org/make/saxophone","stations":9,"upstream":64,"downstream":0,"depth":7,"dek":"Saxophones have more than 600 parts, and their tone holes are pulled out of the tube wall like tiny chimneys.","answer":"A flat trapezoid of thin brass, rolled into a cone and welded, forms the body of a saxophone. Tone holes are drawn outward from holes cut in the tube. The bow and bell are pressed from brass halves, the keywork is machined and soldered on, and the whole horn is lacquered or plated, then pad-sealed and tested.","aka":["sax","alto sax","tenor sax"],"inputs":["brass","steel","solder","silver","lacquer","leather"],"uses":[],"grounds":["silver-ore","lead-ore","zinc-ore","copper-ore","cattle-hide","rock-salt","water","air","tin-ore","crude-oil","coal","iron-ore","limestone","dolomite","manganese-ore","natural-gas","sulfur","corn","sugarcane","chromite","bauxite","quartz","timber","trona","sugar-beet"],"upstreamSlugs":["brass","steel","solder","silver","lacquer","leather","copper","zinc","lead","tin","aluminum","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","silver-ore","lead-ore","zinc-ore","copper-ore","sulfuric-acid","ethanol","acrylic","cattle-hide","rock-salt","water","chromium","air","coke","tin-ore","crude-oil","coal","petroleum-coke","alumina","iron-ore","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","sulfur","corn","sugarcane","yeast","ethylene","propylene","ammonia","methanol","chromite","soda-ash","bauxite","caustic-soda","quartz","charcoal","timber","molasses","naphtha","carbon-dioxide","trona","sugar-beet","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Cut the brass trapezoid","process":"cut","text":"Each body starts as a sheet of brass 0.6 to 0.7 millimeters thick, cut in a trapezoid so it will roll into a cone.","inputs":["brass"]},{"name":"Roll and weld the tube","process":"roll","text":"The sheet is rolled, welded along its seam, and drawn out on a conical chuck. Several rounds of tempering take out the stresses that forming builds in the metal.","inputs":[]},{"name":"Draw out the tone holes","process":"draw","text":"Oblong holes are bored in the tube, and the metal around each one is drawn upward into a raised rim. Selmer has used this method since 1922. It saves soldering on separate chimneys.","inputs":[]},{"name":"Press the bow and bell","process":"stamp","text":"The curved bow joint is pressed in two half-shells and brazed together. Its final size is set by hydraulic inflation, with liquid injected at high pressure into the part inside a die. Bells for alto and tenor saxophones are pressed in halves and argon-welded.","inputs":["brass"]},{"name":"Machine the keywork","process":"machine","text":"Key arms, pad cups, posts and rings are cut, drilled, milled and stamped. Rods and screws are commonly steel.","inputs":["brass","steel"]},{"name":"Solder the keywork on","process":"weld","text":"Posts are positioned on plates, then silver-soldered to the body. After soldering the body goes through a bath that clears solder residue, and workers file it by hand.","inputs":["solder","silver"]},{"name":"Lacquer or plate it","process":"coat","text":"Most saxophones get a thin coat of clear or colored acrylic lacquer to stop the brass from oxidizing. Silver or gold plating is sold as an option.","inputs":["lacquer"]},{"name":"Seal the pads and check leaks","process":"assemble","text":"Leather pads on the key cups must seal the tone holes. Technicians shine a light inside the bore and look for any glow leaking round a pad.","inputs":["leather"]},{"name":"Play-test each horn","process":"inspect","text":"Every instrument is tested in soundproof booths for acoustic and mechanical performance before it ships.","inputs":[]}],"facts":["Adolphe Sax invented the saxophone in the early 1840s and patented it on 28 June 1846.","A saxophone counts as a woodwind despite its brass body, because its sound comes from a single reed on the mouthpiece.","At Selmer, the neck is curved by bending it through ice."],"where":[],"whereNote":null,"sources":[{"title":"Birth of a saxophone at the Henri SELMER Paris factory","url":"https://www.selmer.fr/en/blogs/infos/fabrication-saxophone-selmer"},{"title":"Saxophone","url":"https://en.wikipedia.org/wiki/Saxophone"},{"title":"How Modern Saxophones Are Built","url":"https://stohrermusic.com/preservation-hall/cybersax/graphics/tech/YaniTour/YaniTour_Page_2.html"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"scissors","name":"Scissors","kind":"product","category":"hardware","title":"How scissors are made","url":"https://assemblyline.org/make/scissors","stations":8,"upstream":65,"downstream":0,"depth":10,"dek":"China ships almost two out of every three pairs of scissors that cross a border.","answer":"Sheffield maker Whiteley drop forges each half from carbon steel bar, trims it, sands the handle loops, then drills and taps the pivot hole. The blanks are hardened in a furnace, quenched in oil, tempered and rumbled with ceramic chips. Only then are the blades ground, screwed together, adjusted and tested. Cheaper pairs are often stamped from sheet steel.","aka":["shears","pair of scissors"],"inputs":["steel","screw","paint"],"uses":[],"grounds":["water","iron-ore","limestone","air","dolomite","manganese-ore","natural-gas","zinc-ore","titanium-ore","sulfur","coal","quartz","timber","crude-oil","rock-salt","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["steel","screw","paint","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","steel-wire","zinc","water","titanium-dioxide","pigment","acrylic","tin-can","iron-ore","coke","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","zinc-ore","titanium-ore","chlorine","carbon-black","sulfur","propylene","ammonia","methanol","tinplate","lacquer","ink","coal","quartz","charcoal","timber","crude-oil","rock-salt","naphtha","tin","ethanol","vegetable-oil","phenolic-resin","hydrogen","tin-ore","corn","sugarcane","yeast","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","molasses","benzene","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Drop forge the blanks","process":"forge","text":"A forge stamps each half from a carbon steel bar in its own mold, one mold per style. Trimming then removes excess steel and opens the insides of the handles.","inputs":["steel"]},{"name":"Dress the bows","process":"grind","text":"Every surface of the blank, including the insides of the finger loops, is sanded by hand to take off roughness left by the forge.","inputs":[]},{"name":"Drill and tap the pivot","process":"machine","text":"Each pair is drilled and threaded where the pivot screw will go. The hole's position sets how well the two halves will line up.","inputs":[]},{"name":"Harden and temper","process":"heat-treat","text":"The blanks heat in a furnace and quench in oil, which gives the steel a hard edge. Tempering follows, leaving the handles soft enough to be worked.","inputs":[]},{"name":"Rumble and polish","process":"grind","text":"A vibrating tub of ceramic chips and mild acid smooths rough surfaces, and hand polishing brings up the shine.","inputs":[]},{"name":"Grind the edges","process":"grind","text":"Grinders cut the sharp edges into the hardened blades. Irregular shapes make this job hard to automate.","inputs":[]},{"name":"Join and adjust","process":"assemble","text":"The pivot screw goes in and is set for the right tension. Each pair is then tested on different materials.","inputs":["screw"]},{"name":"Dip the handles","process":"coat","text":"Handles are dipped in primer and then paint, left to drip, and baked in an oven. Others get chrome, gold or ceramic coatings before assembly. A laser marks the blades last.","inputs":["paint"]}],"facts":["In 1761, Robert Hinchliffe of Sheffield made the first scissors from cast steel for the mass market.","The Hangzhou Zhang Xiaoquan company has been making scissors since 1663.","In 2019 China accounted for 64.3% of worldwide scissors exports."],"where":[{"place":"China","share":"64.3% of world scissors exports"}],"whereNote":"2019, share of worldwide exports of scissors.","sources":[{"title":"William Whiteley & Sons: The process","url":"https://www.whiteley.co.uk/about-whiteley/the-process/"},{"title":"Scissors","url":"https://en.wikipedia.org/wiki/Scissors"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"scotch","name":"Scotch whisky","kind":"product","category":"drink","title":"How Scotch whisky is made","url":"https://assemblyline.org/make/scotch","stations":7,"upstream":44,"downstream":0,"depth":6,"dek":"By law every drop sits in oak for at least three years, and a typical single malt spends 10 to 15.","answer":"Malt Scotch is made from malted barley and water. The barley is soaked and germinated, dried over heat or peat smoke, mashed with hot water, fermented with yeast and distilled in copper stills. Grain whisky comes from column stills, and most blends mix the two. All of it must mature in oak in Scotland for at least three years.","aka":["Scotch","single malt Scotch","Scottish whisky"],"inputs":["barley","water","malted-barley","yeast","wine-barrel","glass-bottle"],"uses":[],"grounds":["barley","water","timber","silica-sand","limestone","sugarcane","sugar-beet","rock-salt","trona","iron-ore","air","dolomite","manganese-ore","natural-gas","corn","coal","quartz","crude-oil","sulfur"],"upstreamSlugs":["barley","water","malted-barley","yeast","wine-barrel","glass-bottle","molasses","timber","steel","silica-sand","soda-ash","limestone","polyethylene","sugarcane","sugar-beet","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","rock-salt","ammonia","carbon-dioxide","trona","ethylene","iron-ore","coke","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","corn","naphtha","coal","quartz","charcoal","crude-oil","sulfur","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Soak and sprout the barley","process":"grow","text":"Barley is soaked in water for two to three days and allowed to germinate. Sprouting releases enzymes that turn starch into fermentable sugar. After three to five days, hot air halts the germination.","inputs":["barley","water"]},{"name":"Dry over peat smoke","process":"dry","text":"Hot air stops the sprouting, and in many cases smoke from a peat fire is added during the heating for phenols that give a smoky aroma. Islay malts have a reputation for being the peatiest.","inputs":[]},{"name":"Mash with hot water","process":"mix","text":"The malt is milled into coarse grist and mashed in a large kettle called a mash tun with three portions of hot water, at about 60, 72 and 88 degrees Celsius. The sugary liquid is called wort.","inputs":["water","malted-barley"]},{"name":"Ferment in the washback","process":"ferment","text":"Yeast is added to the wort in a large vessel called a washback. Within about three days the liquid reaches 5 to 7 percent alcohol and is known as wash.","inputs":["yeast"],"spec":"up to 3 days"},{"name":"Distill in pot stills","process":"refine","text":"The wash is distilled in copper pot stills twice, sometimes three times. The first pass gives low wines of about 20 to 30 percent, and the second gives new make spirit of 60 to 70 percent.","inputs":[]},{"name":"Mature in oak casks","process":"dry","text":"The new spirit is diluted to about 60 percent and put into oak casks, often ones used before for American whiskey or sherry. Scotch must mature for at least three years, and a typical single malt spends 10 to 15.","inputs":["wine-barrel"],"spec":"at least 3 years"},{"name":"Vat, dilute, bottle","process":"fill","text":"Whisky comes out of the cask at around 60 to 63 percent. Water is added to bring it to a bottling strength usually between 40 and 46 percent.","inputs":["glass-bottle","water"]}],"facts":["The earliest written record of Scotch distilling is a 1494 note that eight bolls of malt were given to Friar John Cor to make aqua vitae.","Aeneas Coffey patented a column still in 1831 that let distilleries run continuously.","George Smith took out the first distillery licence under the 1823 Excise Act and founded Glenlivet in 1824."],"where":[],"whereNote":null,"sources":[{"title":"Scotch whisky","url":"https://en.wikipedia.org/wiki/Scotch_whisky"},{"title":"Single malt whisky","url":"https://en.wikipedia.org/wiki/Single_malt_whisky"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"screw","name":"Screw","kind":"product","category":"hardware","title":"How screws are made","url":"https://assemblyline.org/make/screw","stations":7,"upstream":28,"downstream":13,"depth":6,"dek":"Screw threads are squeezed into the metal, not cut, which makes them stronger.","answer":"Screws are made from coils of steel wire in three main steps: heading, thread rolling and coating. A machine cuts a blank, squeezes a head onto it, then rolls a spiral thread into the shank between two hardened dies. A zinc or similar plating protects the finished screw from rust.","aka":["wood screw","machine screw"],"inputs":["steel-wire","zinc"],"uses":["scissors","rubiks-cube","ice-skates","action-figure","harmonica","light-switch","power-outlet","suitcase","high-heels","eyeglass-frame","loudspeaker","game-console","graphics-card"],"grounds":["zinc-ore","air","sulfur","water","iron-ore","limestone","dolomite","manganese-ore","natural-gas","coal","quartz","timber","crude-oil"],"upstreamSlugs":["steel-wire","zinc","steel","zinc-ore","air","sulfuric-acid","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","sulfur","water","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","coal","quartz","charcoal","timber","crude-oil"],"downstreamSlugs":["scissors","rubiks-cube","ice-skates","action-figure","harmonica","light-switch","power-outlet","suitcase","high-heels","eyeglass-frame","loudspeaker","game-console","graphics-card"],"steps":[{"name":"Cut blanks from wire","process":"cut","text":"Wire is fed from a large coil and chopped into short pieces, one per screw. Bigger screws start from round bar instead of wire.","inputs":["steel-wire"]},{"name":"Upset the head","process":"forge","text":"Punches squeeze one end of each blank into a head at room temperature. A cold heading machine can turn out hundreds of parts a minute, and the grain of the steel flows around the head instead of being severed.","inputs":[],"spec":"60 to 400 parts per minute"},{"name":"Polish the blanks","process":"grind","text":"Before threading, the headed blanks are cleaned and polished so that the dies grip a smooth surface.","inputs":[]},{"name":"Roll the spiral","process":"roll","text":"The shank is pressed between hardened dies that carry the thread pattern in reverse. The steel flows into the grooves, which makes rolled threads stronger than cut ones.","inputs":[],"spec":"10 to 20 percent more tensile strength"},{"name":"Tumble with wood and leather","process":"grind","text":"Screws spin in drums with wood and leather media that scrub off burrs and leave the surface bright.","inputs":[]},{"name":"Plate against rust","process":"coat","text":"Most screws receive a coating, commonly a zinc electroplate, before packing.","inputs":["zinc"]},{"name":"Check and pack","process":"inspect","text":"Samples are gauged for thread fit and head size, then counted or weighed into boxes.","inputs":[]}],"facts":["More screw threads are produced each year than any other machine element.","The first screw factory in the United States was built in 1821 by Hardman Philips near Philipsburg.","Rolled threads can be 10 to 20 percent stronger in tension than cut ones."],"where":[],"whereNote":null,"sources":[{"title":"Screw","url":"https://en.wikipedia.org/wiki/Screw"},{"title":"Threading (manufacturing)","url":"https://en.wikipedia.org/wiki/Thread_rolling"},{"title":"Cold heading","url":"https://en.wikipedia.org/wiki/Cold_heading"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"seat-belt","name":"Seat belt","kind":"product","category":"machines","title":"How seat belts are made","url":"https://assemblyline.org/make/seat-belt","stations":8,"upstream":41,"downstream":0,"depth":8,"dek":"US rules want a lap belt's strap to hold 26,689 newtons before it breaks, and to do it at 46 mm wide.","answer":"A seat belt strap, called webbing, is woven on a narrow needle loom from nearly untwisted polyester yarn, then dyed, heat set and finished. A steel pin sewn into one end anchors it in a slotted spool, and a pre-wound spiral spring supplies the rewind. Federal rules set the floor for width, strength, stretch and abrasion, and samples are tested against them.","aka":["safety belt","car seat belt"],"inputs":["polyester","steel","thread","plastic"],"uses":[],"grounds":["water","natural-gas","iron-ore","limestone","air","dolomite","manganese-ore","crude-oil","coal","quartz","timber","sulfur","corn","sugarcane","sugar-beet"],"upstreamSlugs":["polyester","steel","thread","plastic","pet-plastic","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","water","naphtha","natural-gas","ethylene","propylene","p-xylene","ethylene-glycol","iron-ore","coke","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","crude-oil","hydrogen","carbon-dioxide","coal","quartz","charcoal","timber","sulfur","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Weave on a needle loom","process":"weave","text":"Polyester multifilament warp runs into a narrow-fabric needle loom, where a reciprocating needle carries weft across. Needles scrape warp far less than old shuttles did. A typical strap has about 300 warp threads in its 46 mm width.","inputs":["polyester"]},{"name":"Dye and heat-set","process":"dye","text":"The woven strap goes through dyeing and heat setting. Some makers add a surface finish of resin or oil, which helps it stand up to abrasion.","inputs":[]},{"name":"Sew in the pin","process":"sew","text":"One end of the strap is folded into a loop around a strong steel pin and sewn shut. That pin stops the end from pulling through the spool under load.","inputs":["steel","thread"]},{"name":"Thread the spool","process":"assemble","text":"The webbing is threaded through a slot in the spool's core, often a one-piece die casting, until the pin seats in the slot and leaves a smooth surface to wind on. One patent notes that two-slot designs spread the load but are harder to automate.","inputs":[]},{"name":"Fit the rewind spring","process":"assemble","text":"A fully wound spiral spring can arrive sealed in a casing, held by a U-shaped clip until it is installed. Its inner end drives the shaft, and it pulls the strap back onto the reel.","inputs":[]},{"name":"Add the locking mechanism","process":"assemble","text":"An inertial lock goes on the reel. One type answers a fast pull on the strap through a centrifugal clutch, and the spool stops paying out.","inputs":[]},{"name":"Fit the buckle and latch","process":"assemble","inputs":["steel","plastic"],"text":"A stamped steel latch plate goes on the webbing, and the buckle it clicks into is built as its own unit from steel and plastic."},{"name":"Test to the standard","process":"inspect","text":"The US federal safety standard requires at least 46 mm width on webbing that touches the wearer, and a lap belt may stretch no more than 20 percent at 11,120 newtons. After abrasion, webbing must keep 75 percent of its required strength, and hardware must resist corrosion.","inputs":[],"spec":"26,689 N minimum breaking strength for a lap belt"}],"facts":["Modern seat belt webbing has a tensile strength of about 3,000 to 6,000 pounds.","The first modern three-point seat belt was patented in 1955 by Roger W. Griswold and Hugh DeHaven.","Ford said 20% of its 1956 buyers chose factory-fitted belts."],"where":[],"whereNote":null,"sources":[{"title":"US6772797B2, Webbing for seat belt and method of manufacturing webbing for seat belt","url":"https://patents.google.com/patent/US6772797"},{"title":"US6336606, Spool for a seat belt retractor","url":"https://patents.google.com/patent/US6336606"},{"title":"US4340190A, Seat belt retractor spring assembly","url":"https://patents.google.com/patent/US4340190A/en"},{"title":"49 CFR 571.209, Seat belt assemblies","url":"https://www.law.cornell.edu/cfr/text/49/571.209"},{"title":"Seat belt","url":"https://en.wikipedia.org/wiki/Seat_belt"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"seawater","name":"Seawater","kind":"raw","category":"ground","title":"How seawater is collected","url":"https://assemblyline.org/make/seawater","stations":3,"upstream":0,"downstream":49,"depth":0,"dek":"Every kilogram of seawater holds about 35 grams of dissolved salt, and industry pulls it out in two ways.","answer":"Seawater is drawn through intake pipes or shallow channels, screened to remove debris, and then put to work. Salt makers let it evaporate in shallow sunlit ponds, leaving salt behind. Desalination plants instead strip the salt out to make fresh water, using heat or membranes.","aka":["ocean water","sea water","brine"],"inputs":[],"uses":["table-salt","cultured-pearl"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["table-salt","cultured-pearl","butter","cheese","margarine","mayonnaise","ketchup","mustard","soy-sauce","peanut-butter","bread","instant-noodles","croissant","pretzel","corn-flakes","potato-chips","popcorn","hot-dog","bacon","canned-tuna","chicken-nuggets","cream-cheese","mozzarella","parmesan","cheddar","oat-milk","hot-sauce","salsa","pickles","sauerkraut","kimchi","bagel","baguette","sourdough","crackers","imitation-crab","sausage","salami","ham","beef-jerky","canned-meat","sausage-casing","modeling-clay","caramel","cake-mix","dish-soap","toffee","fish-sticks","frozen-pizza"],"steps":[{"name":"Draw it from the sea","process":"drill","text":"Pumps lift seawater through intake pipes, or tidal channels let it flow into holding ponds. The water carries about 3.5% dissolved salts, mostly sodium and chloride.","inputs":[]},{"name":"Screen out the debris","process":"separate","text":"Screens and filters take out seaweed, shells and sediment before the water reaches the plant or the ponds.","inputs":[]},{"name":"Spread it in shallow pans","process":"dry","text":"In a salt evaporation pond, seawater or another brine is fed into shallow artificial pans. Sunlight reaches the water, evaporation takes the water away, and the salt is later harvested.","inputs":[]}],"facts":["A kilogram of seawater holds about 35 grams of dissolved salts, mostly sodium and chloride.","Global desalination capacity in 2020 was roughly 97 million cubic meters a day from over 16,800 plants.","In evaporation ponds, algae and microorganisms turn the water colors from pale green to bright red as the salinity rises."],"where":[],"whereNote":null,"sources":[{"title":"Seawater","url":"https://en.wikipedia.org/wiki/Seawater"},{"title":"Salt evaporation pond","url":"https://en.wikipedia.org/wiki/Salt_evaporation_pond"},{"title":"Desalination","url":"https://en.wikipedia.org/wiki/Desalination"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"seaweed","name":"Seaweed","kind":"raw","category":"farm","title":"How seaweed is farmed and harvested","url":"https://assemblyline.org/make/seaweed","stations":3,"upstream":0,"downstream":1,"depth":0,"dek":"More than half of the world's farmed seaweed comes from China, mostly grown on lines in shallow sea.","answer":"Seaweed farmers tie seedlings to ropes or monofilament lines and string them between stakes in shallow water, or float long-lines anchored to the bottom in water about 7 meters deep. The plants grow in the sea with little need for fertilizer or fresh water, and are cut or hauled in when mature.","aka":["kelp farming","seaweed aquaculture","kelp","nori","algae farming"],"inputs":[],"uses":["nori"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["nori"],"steps":[{"name":"Tie seedlings to lines","process":"grow","text":"In the off-bottom method seedlings are tied to monofilament lines strung between stakes driven into the shallow sea floor. The earliest Philippine guides recommended reef flats at about one meter depth at low tide.","inputs":[]},{"name":"Float long-lines in deeper water","process":"grow","text":"Long-line farms anchor floating cultivation lines to the bottom in water around 7 meters deep. Saccharina kelp, Undaria, Eucheuma, Kappaphycus and Gracilaria are all raised this way, with low technology and a lot of hand labor.","inputs":[]},{"name":"Cut and haul the crop","process":"harvest","text":"Farmers take the mature seaweed from the lines. Seaweed is an extractive crop that needs little fertilizer or fresh water, so it has a smaller footprint than fed aquaculture.","inputs":[]}],"facts":["Seaweed is a name for thousands of species of marine algae, in red, brown and green groups.","Seven taxa dominate cultivation, including Eucheuma, Gracilaria and the Pyropia used for nori.","In Japan, nori production is worth US$2 billion a year."],"where":[{"place":"China","share":"58.62% of world output"},{"place":"Indonesia","share":"28.6%"},{"place":"South Korea","share":"5.09%"},{"place":"Philippines","share":"4.19%"}],"whereNote":"2022, share of farmed seaweed production; world production in 2019 was over 35 million tonnes.","sources":[{"title":"Seaweed farming","url":"https://en.wikipedia.org/wiki/Seaweed_farming"},{"title":"Seaweed","url":"https://en.wikipedia.org/wiki/Seaweed"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"semolina","name":"Semolina","kind":"material","category":"food","title":"How semolina is milled","url":"https://assemblyline.org/make/semolina","stations":6,"upstream":2,"downstream":1,"depth":1,"dek":"Durum is so hard it shatters into coarse grit, and millers sell that grit as semolina instead of grinding it finer.","answer":"Semolina is a coarse flour milled from durum wheat. Grooved steel rollers set slightly narrower than the kernels crack the grain, flaking off the bran and germ and breaking the starchy center into coarse pieces. Sifting separates the grains by size. Pale yellow durum semolina is the main ingredient in dry pasta.","aka":["durum semolina","pasta flour","farina"],"inputs":["durum-wheat","water"],"uses":["pasta"],"grounds":["durum-wheat","water"],"upstreamSlugs":["durum-wheat","water"],"downstreamSlugs":["pasta"],"steps":[{"name":"Clean and temper the grain","process":"wash","text":"Wheat is cleaned of dust, stones and chaff, then dampened and rested so the bran toughens and comes away in bigger pieces.","inputs":["durum-wheat","water"]},{"name":"Crack it between rollers","process":"crush","text":"Grooved steel rollers are set a little tighter than the width of a kernel. They flake off the bran and germ and crack the starchy endosperm into coarse pieces.","inputs":[]},{"name":"Sift by particle size","process":"separate","text":"Sieves pull out the pieces of endosperm that meet the coarse standard. Under the Codex rule, no more than 79 percent may pass a 315-micron sieve.","inputs":[],"spec":"no more than 79% passes 315 microns"},{"name":"Blow out loose bran","process":"separate","inputs":[],"text":"Purifiers shake the sifted pieces over sieves while air lifts away flakes of bran, leaving clean, pale endosperm."},{"name":"Regrind the oversize bits","process":"grind","text":"Pieces that are too big go back through the rollers again. Fine flour that results is sold separately.","inputs":[]},{"name":"Bag the yellow grains","process":"package","text":"The finished semolina is pale yellow and gritty to the touch. It is packed for pasta factories, couscous makers and bakeries.","inputs":[]}],"facts":["Commercial dry pasta is made almost exclusively from durum semolina.","Semolina made from common wheat is beige and is called farina in the United States.","The word semolina comes from the Italian semolino, from semola, meaning coarse grains."],"where":[],"whereNote":null,"sources":[{"title":"Semolina","url":"https://en.wikipedia.org/wiki/Semolina"},{"title":"Durum","url":"https://en.wikipedia.org/wiki/Durum"},{"title":"Semolina","url":"https://bakerpedia.com/ingredients/semolina/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"needle","name":"Sewing needle","kind":"product","category":"hardware","title":"How sewing needles are made","url":"https://assemblyline.org/make/needle","stations":8,"upstream":34,"downstream":0,"depth":6,"dek":"A sewing needle starts as a length of wire long enough for two, pointed at both ends and split in the middle.","answer":"Machinery pulls steel wire off spools, straightens it and cuts a length often long enough for two needles. Swaging shapes the shank and blade cold, a high-speed stamper pierces the eye, and milling forms the point. The needles are then heated, quenched in oil, deep frozen, tumbled with abrasive and plated.","aka":["hand sewing needle","sharps"],"inputs":["steel-wire","nickel","gold"],"uses":[],"grounds":["nickel-ore","gold-ore","water","sulfur","air","limestone","zinc-ore","rock-salt","iron-ore","dolomite","manganese-ore","natural-gas","coal","quartz","timber","crude-oil"],"upstreamSlugs":["steel-wire","nickel","gold","steel","nickel-ore","sulfuric-acid","gold-ore","water","lime","zinc","chlorine","pig-iron","magnesium","steel-scrap","oxygen","manganese","argon","sulfur","air","limestone","zinc-ore","rock-salt","iron-ore","coke","dolomite","silicon","propane","manganese-ore","natural-gas","coal","quartz","charcoal","timber","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Straighten the wire","process":"draw","text":"Machines pull wire from two coils at once and guide it through narrow passages that take out the kinks.","inputs":["steel-wire"]},{"name":"Cut the lengths","process":"cut","text":"The wire is chopped to length and dropped down a shaking chute into bins. One patented method cuts a blank with enough material for two needles, parted later.","inputs":[]},{"name":"Swage shank and blade","process":"forge","text":"Pressure cold-forms the metal into its new shape without removing any. Trademarks and size markings are stamped in during this step.","inputs":[]},{"name":"Stamp the eye","process":"stamp","text":"A carrier strip holds the blanks while a precision stamper pierces each eye. The edges of the hole are then rounded from both sides so thread will not fray on them.","inputs":[]},{"name":"Mill the point","process":"grind","text":"The blank turns repeatedly against a cutter, which forms the point. The quality of the finished needle depends heavily on this step.","inputs":[]},{"name":"Harden in oil","process":"heat-treat","text":"The needles are heated, quenched in oil and slowly cooled, which adds strength and reduces brittleness. A deep freeze makes them more elastic.","inputs":[]},{"name":"Tumble smooth","process":"grind","text":"Batches go into a tub-like machine full of abrasive media, where vibration and a chemical treatment polish them.","inputs":[]},{"name":"Plate the surface","process":"coat","text":"Nickel or gold plating protects the steel and lets it slide through cloth. Finished needles go through a final inspection.","inputs":["nickel","gold"]}],"facts":["A bone needle estimated to be around 50,000 years old was found in Denisova Cave.","England began making needles in 1639 at Redditch using the drawn-wire technique still in common use.","Bronze Age needle makers made the eye by turning the wire back on itself and redrawing it through the die."],"where":[],"whereNote":null,"sources":[{"title":"Goldstar Tool: How sewing machine needles are made","url":"https://www.goldstartool.com/blog/how-sewing-machine-needles-made.htm"},{"title":"US4524815A: Method of producing sewing machine needles","url":"https://patents.google.com/patent/US4524815"},{"title":"Sewing needle","url":"https://en.wikipedia.org/wiki/Sewing_needle"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"thread","name":"Sewing thread","kind":"material","category":"textiles","title":"How sewing thread is made","url":"https://assemblyline.org/make/thread","stations":7,"upstream":19,"downstream":53,"depth":7,"dek":"Sewing thread is made weaker than the fabric on purpose, so a seam gives way before the garment tears.","answer":"Polyester thread starts with chips melted and forced through a spinneret, while bales of short staple fiber are opened, carded and drawn into roving. On a ring spinning frame, filament can run down the middle with staple wrapped around it. Two, three or four such yarns are twisted the opposite way to lock them, then lubricated and wound.","aka":["polyester thread","cotton thread","sewing cotton"],"inputs":["polyester","water"],"uses":["airbag","baseball","soccer-ball","fireworks","bike-helmet","candle","sofa","pillow","ice-skates","fishing-rod","football","volleyball","kite","yo-yo","fashion-doll","tampon","seat-belt","hoodie","dress-shirt","suit","silk-tie","underwear","leggings","swimsuit","down-jacket","raincoat","winter-gloves","leather-belt","handbag","backpack","suitcase","wallet","hiking-boots","high-heels","felt-hat","blanket","curtain","flag","book","jeans","t-shirt","socks","sweater","sneaker","leather-shoe","baseball-cap","towel","mattress","umbrella","zipper","teddy-bear"],"grounds":["water","natural-gas","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["polyester","water","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","oxygen","carbon-dioxide","crude-oil","hydrogen","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["airbag","baseball","soccer-ball","fireworks","bike-helmet","candle","sofa","pillow","ice-skates","fishing-rod","football","volleyball","kite","yo-yo","fashion-doll","tampon","seat-belt","hoodie","dress-shirt","suit","silk-tie","underwear","leggings","swimsuit","down-jacket","raincoat","winter-gloves","leather-belt","handbag","backpack","suitcase","wallet","hiking-boots","high-heels","felt-hat","blanket","curtain","flag","book","jeans","t-shirt","socks","sweater","sneaker","leather-shoe","baseball-cap","towel","mattress","umbrella","zipper","teddy-bear","car","electric-car"],"steps":[{"name":"Melt-spin the filament","process":"extrude","text":"Polymer chips melt and push under pressure through a spinneret. The filaments cool, gather into a continuous yarn and are stabilized to make the core.","inputs":["polyester"]},{"name":"Open and card staple","process":"separate","text":"Bales of short fiber are opened and blended. Cards separate each fiber from the next and release impurities, then bring them together in a rope called a sliver. Cotton needs an extra cleaning step.","inputs":["polyester"]},{"name":"Draw out the sliver","process":"draw","text":"Typically 6 or 8 slivers run together through rollers whose front pair turns faster than the back. Polyester gets two drawing stages. A speed frame then thins it to roving and adds a slight twist.","inputs":[]},{"name":"Ring spin the singles","process":"spin","text":"Rollers draw the roving finer and a ring frame adds high twist, usually in the S direction. For corespun thread, stabilized filament comes in behind the front rollers so it is not stretched, and staple forms a sheath around it.","inputs":["polyester"]},{"name":"Twist the plies","process":"spin","text":"After clearing and splicing, two, three or four yarns are wound together and twisted in the opposite direction, usually Z. Too little of this finishing twist and the thread frays. Too much and it snarls.","inputs":[]},{"name":"Dye and lubricate","process":"dye","text":"Thread is dyed to color, then treated with lubricant so it runs properly through a sewing machine.","inputs":["water"]},{"name":"Wind and test","process":"package","text":"The finished thread is wound onto final packages, and samples are checked for strength before shipping.","inputs":[]}],"facts":["Thread weight is often given in tex, the mass in grams of 1,000 meters, and in denier, the mass in grams of 9,000 meters.","In the common weight system for thread, a bigger number means a thinner thread, because it counts the kilometers needed to weigh 1 kilogram.","Garments are usually sewn with thread weaker than the fabric, so a stressed seam breaks before the garment does."],"where":[],"whereNote":null,"sources":[{"title":"Coats: Thread production","url":"https://www.coats.com/info-hub/thread-production/"},{"title":"Sewing thread","url":"https://en.wikipedia.org/wiki/Sewing_thread"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"shampoo","name":"Shampoo","kind":"product","category":"body-health","title":"How shampoo is made","url":"https://assemblyline.org/make/shampoo","stations":8,"upstream":49,"downstream":0,"depth":7,"dek":"Most shampoo is mainly water, held together with a foaming detergent often derived from coconut oil.","answer":"Shampoo is a big batch of water blended with detergents that lift oil from hair, plus a second foaming agent, thickeners, conditioners, perfume and preservatives. The main detergent is usually made from coconut oil. Operators add the ingredients to a stirred tank in a set order, check thickness and acidity, then pump the finished liquid into bottles.","aka":["hair wash","hair shampoo"],"inputs":["vegetable-oil","ethylene","sulfuric-acid","caustic-soda","water","rock-salt","silicone","perfume","plastic-bottle"],"uses":[],"grounds":["water","rock-salt","soybeans","rapeseed","clay","natural-gas","sulfur","air","silica-sand","oranges","vanilla-pods","crude-oil","quartz","coal","timber","corn","sugarcane","limestone","trona","sugar-beet"],"upstreamSlugs":["vegetable-oil","ethylene","sulfuric-acid","caustic-soda","water","rock-salt","silicone","perfume","plastic-bottle","soybeans","rapeseed","hexane","clay","naphtha","natural-gas","sulfur","air","silicon","methanol","hydrochloric-acid","silica-sand","oranges","vanilla-pods","ethanol","glass-bottle","pet-plastic","crude-oil","hydrogen","quartz","coke","coal","charcoal","timber","chlorine","corn","sugarcane","yeast","soda-ash","limestone","polyethylene","p-xylene","ethylene-glycol","molasses","ammonia","carbon-dioxide","lime","trona","oxygen","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Make the fatty alcohol","process":"react","text":"Oils from coconut or palm are turned into fatty alcohols, the oily backbone of the main cleaning ingredient.","inputs":["vegetable-oil"]},{"name":"Ethoxylate the alcohol","process":"react","text":"Part of the batch is reacted with ethylene oxide, a product of ethylene, to make a gentler form that foams well and softens water.","inputs":["ethylene"]},{"name":"Sulfate and neutralize","process":"react","text":"The alcohols are treated so they carry a sulfate group and then neutralized, giving a detergent that traps oil and dirt. Sodium laureth sulfate is the usual result.","inputs":["sulfuric-acid","caustic-soda"]},{"name":"Fill the mixing tank","process":"mix","text":"Purified water goes into a large stirred tank first. The detergent and a second foaming agent are added next, then warmed together until the mixture is clear.","inputs":["water"]},{"name":"Thicken with salt","process":"mix","text":"Table salt is stirred in to thicken the liquid. A small amount at a time is added because too much makes the mixture thin out again.","inputs":["rock-salt"]},{"name":"Add conditioners and scent","process":"mix","text":"Silicone, polymers that smooth hair, perfume, dye and preservatives are blended in at gentle speed, since fast stirring whips in air bubbles.","inputs":["silicone","perfume"]},{"name":"Test and adjust","process":"inspect","text":"Lab staff take a sample to check thickness, acidity and clarity. Small additions of acid or salt bring the batch back to the target.","inputs":[]},{"name":"Fill the bottles","process":"fill","text":"Pumps fill rows of bottles at high speed. Caps are screwed on, and labels are applied and checked before cartons are packed.","inputs":["plastic-bottle"]}],"facts":["The word shampoo entered English in 1762 from the Hindi word for pressing, kneading or soothing, which named a head massage with hair oil.","In 1900, German perfumer Josef Wilhelm Rausch developed the first liquid hair washing soap and named it Champooing."],"where":[],"whereNote":null,"sources":[{"title":"Shampoo","url":"https://en.wikipedia.org/wiki/Shampoo"},{"title":"Surfactant","url":"https://en.wikipedia.org/wiki/Surfactant"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sheet-steel","name":"Sheet steel","kind":"material","category":"metals","title":"How sheet steel is made","url":"https://assemblyline.org/make/sheet-steel","stations":7,"upstream":27,"downstream":41,"depth":5,"dek":"A slab thicker than a cinder block is squeezed into a ribbon a few millimeters thick and coiled like tape.","answer":"Sheet steel starts as a cast slab, 180 to 250 millimeters thick, that is reheated and rolled through a hot strip mill into a long coil. The coil is pickled in acid to remove scale, rolled again cold to make it thinner and stronger, annealed to make it workable, and sometimes coated with zinc.","aka":["flat-rolled steel","steel coil","galvanized sheet","cold-rolled steel"],"inputs":["steel","zinc"],"uses":["electric-motor","transformer","refrigerator","microwave-oven","washing-machine","vacuum-cleaner","safety-pin","steel-pipe","padlock","ball-bearing","car","electric-car","airbag","shipping-container","elevator","dishwasher","air-conditioner","ceiling-fan","water-heater","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad"],"grounds":["zinc-ore","air","iron-ore","limestone","dolomite","water","manganese-ore","natural-gas","sulfur","coal","quartz","timber","crude-oil"],"upstreamSlugs":["steel","zinc","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","iron-ore","coke","limestone","dolomite","silicon","propane","water","manganese-ore","natural-gas","sulfur","coal","quartz","charcoal","timber","crude-oil"],"downstreamSlugs":["electric-motor","transformer","refrigerator","microwave-oven","washing-machine","vacuum-cleaner","safety-pin","steel-pipe","padlock","ball-bearing","car","electric-car","airbag","shipping-container","elevator","dishwasher","air-conditioner","ceiling-fan","water-heater","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","drone","locomotive","blender","treadmill","subway-train","game-console","inkjet-printer","graphics-card","phone-charger","container-ship","bicycle","motorcycle","skateboard","roller-skates","yo-yo","skyscraper"],"steps":[{"name":"Heat the slab through","process":"roll","text":"Slabs from the caster go straight to the rolling mill if they are still hot. Cold ones are soaked in a gas-fired pit or furnace first. The steel must stay above its recrystallization temperature, so the grains reform as fast as they are squashed.","inputs":["steel"]},{"name":"Squeeze it into strip","process":"roll","text":"The slab passes through a train of roll stands, each pressing it thinner and longer than the last. Hot-rolled steel has little built-in direction in its strength and few locked-in stresses.","inputs":[]},{"name":"Wind it into coils","process":"roll","text":"The output from a strip mill is coiled. Coils are either sold as hot-rolled sheet or fed to the cold mill, and a coil holds a very long strip.","inputs":[]},{"name":"Dissolve the scale","process":"wash","text":"Hot steel grows a dark crust of mill scale. Acid baths strip it, so the cold rolls meet clean metal and do not press the scale into the surface.","inputs":[]},{"name":"Roll it cold","process":"roll","text":"At room temperature, the steel is rolled much thinner. This smooths the surface, holds tighter tolerances and makes the metal stronger by strain hardening, by as much as 20 percent. A full-hard grade is reduced in thickness by 50 percent.","inputs":[]},{"name":"Anneal it soft again","process":"heat-treat","text":"Cold rolling leaves the steel hard and stiff. Heating it in a controlled furnace restores its ductility, so it can later be pressed into a car door or folded into a duct.","inputs":[]},{"name":"Skin-pass and coat","process":"coat","text":"A last light squeeze, called a skin pass, sets the surface finish. Much sheet is then dipped in molten zinc, which is hot-dip galvanizing, so a scratch in the coat still does not let rust start.","inputs":["zinc"]}],"facts":["Squashing steel cold at room temperature can make it up to 20 percent stronger through strain hardening, with no heat treatment at all.","Zinc protects steel even where the coating is scratched, because zinc corrodes first, within about 5 millimeters of the damage."],"where":[],"whereNote":null,"sources":[{"title":"Hot rolling","url":"https://en.wikipedia.org/wiki/Hot_rolling"},{"title":"Cold rolling","url":"https://en.wikipedia.org/wiki/Cold_rolling"},{"title":"Continuous casting","url":"https://en.wikipedia.org/wiki/Continuous_casting"},{"title":"Galvanization","url":"https://en.wikipedia.org/wiki/Galvanization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"shipping-container","name":"Shipping container","kind":"product","category":"machines","title":"How shipping containers are made","url":"https://assemblyline.org/make/shipping-container","stations":8,"upstream":77,"downstream":0,"depth":10,"dek":"A shipping container is a steel box whose corrugated walls do most of the work of holding up a stack of its neighbors.","answer":"A shipping container is built from rolled weathering steel and a plywood floor. Corrugated side and roof panels are welded to a rigid frame with strong corner fittings. Doors, rubber seals and locking bars are added, the box is sprayed with paint, and each unit gets a code painted on the outside.","aka":["intermodal container","freight container","cargo container","sea can"],"inputs":["steel","sheet-steel","plywood","rubber","paint"],"uses":[],"grounds":["timber","natural-latex","sulfur","water","iron-ore","limestone","air","dolomite","manganese-ore","natural-gas","zinc-ore","crude-oil","titanium-ore","coal","quartz","rock-salt","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["steel","sheet-steel","plywood","rubber","paint","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc","timber","adhesive","natural-latex","synthetic-rubber","carbon-black","sulfur","water","titanium-dioxide","pigment","acrylic","tin-can","iron-ore","coke","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","zinc-ore","polyethylene","epoxy","polyurethane","paraffin-wax","naphtha","benzene","ethylene","styrene","crude-oil","titanium-ore","chlorine","propylene","ammonia","methanol","tinplate","lacquer","ink","coal","quartz","charcoal","phenol","acetone","caustic-soda","nitric-acid","hydrogen","toluene","rock-salt","tin","ethanol","vegetable-oil","phenolic-resin","tin-ore","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","formaldehyde","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Roll the weathering steel","process":"roll","text":"Container steel is a weathering grade, usually called CorTen, that builds a protective rust layer instead of eating itself away. It is rolled thin and cut into panels.","inputs":["steel"]},{"name":"Corrugate the panels","process":"stamp","text":"Rollers and presses fold the sheets into waves. Corrugating adds much of the rigidity and stacking strength to the thin walls.","inputs":["sheet-steel"]},{"name":"Weld the frame and corners","process":"weld","text":"Steel rails and posts are welded into a rectangular frame. Strong corner castings give the container its twistlock points, which hold a stack together on a ship.","inputs":[]},{"name":"Weld on the panels","process":"weld","text":"Wall, roof and end panels are welded to the frame so every seam is sealed against water.","inputs":[]},{"name":"Lay the plywood floor","process":"assemble","text":"Marine plywood boards are fitted to steel cross-members and fastened down. Forklifts will drive over this floor for years.","inputs":["plywood"]},{"name":"Hang the doors","process":"assemble","text":"Double doors with locking bars go on one end, sealed with rubber gaskets that keep rain and spray out.","inputs":["rubber"]},{"name":"Paint and mark","process":"coat","text":"The box is sprayed with paint, and an identification code is stenciled on the outside. Every container carries its own unique code.","inputs":["paint"]},{"name":"Check the box","process":"inspect","text":"Inspectors test the doors and look for leaks and weak welds. Boxes have to carry 20 to 25 tonnes of cargo.","inputs":[]}],"facts":["Most containers are 8 feet wide and either 20 or 40 feet long, under the ISO 668 standard.","The 1948 US Army Transporter was a corrugated steel container with double doors that carried 9,000 pounds."],"where":[],"whereNote":null,"sources":[{"title":"Intermodal container","url":"https://en.wikipedia.org/wiki/Intermodal_container"},{"title":"Container ship","url":"https://en.wikipedia.org/wiki/Container_ship"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"shoelace","name":"Shoelace","kind":"product","category":"textiles","title":"How shoelaces are made","url":"https://assemblyline.org/make/shoelace","stations":5,"upstream":37,"downstream":0,"depth":7,"dek":"A shoelace tip starts as clear tape that a machine wraps around the braid and melts into place.","answer":"Yarn is wound on spools and set on a braiding machine, where spools weave past each other in circles to make a tube, or in C-shaped tracks to make a flat braid. The continuous cord goes through a tipping machine, which wraps clear acetate tape around it and applies heat and often acetone so the tape bonds. A cut through the middle of the wrap leaves a tip on each side.","aka":["shoe laces","bootlaces","aglet"],"inputs":["polyester","cotton-yarn","cellulose-acetate","acetone"],"uses":[],"grounds":["raw-cotton","water","air","timber","crude-oil","natural-gas","rock-salt","limestone","coal","corn","sugarcane","sugar-beet"],"upstreamSlugs":["polyester","cotton-yarn","cellulose-acetate","acetone","pet-plastic","raw-cotton","wood-pulp","acetic-anhydride","water","plasticizer","benzene","propylene","air","p-xylene","ethylene","ethylene-glycol","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","methanol","carbon-monoxide","naphtha","hydrogen","toluene","crude-oil","natural-gas","carbon-dioxide","rock-salt","limestone","coal","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Wind the yarn","process":"spin","text":"Fibers of cotton or polyester are twisted into strands and wound onto bobbins, ready to mount on the braider.","inputs":["polyester","cotton-yarn"]},{"name":"Braid the cord","process":"weave","text":"Spools run in interlocking circles on a Maypole braider and make a double-walled tube. Flat braiders reverse the spools along C-shaped tracks for a thinner single wall.","inputs":[]},{"name":"Wrap the acetate tape","process":"laminate","text":"A tipping machine wraps clear acetate tape, twice the width of the tip, around the uncut cord. Controlled heat and often acetone melt it onto the yarn.","inputs":["cellulose-acetate","acetone"]},{"name":"Cut through the wrap","process":"cut","text":"Once the tape has cooled, the blade cuts through its center, leaving half on each side. Every cut therefore finishes the end of one lace and the start of the next.","inputs":[]},{"name":"Inspect and bundle","process":"package","text":"Excess material is trimmed, laces are inspected for quality, and they are paired up and packaged for retailers.","inputs":[]}],"facts":["Aglets were originally made of metal, glass or stone, and wealthy Romans had theirs made of precious metals.","Cotton laces have a rough surface and hold a knot better than polyester ones."],"where":[],"whereNote":null,"sources":[{"title":"Ian's Shoelace Site: Shoelace construction","url":"https://www.fieggen.com/shoelace/shoelace-construction.htm"},{"title":"MJ Webbing: Shoelace producing procedure","url":"https://www.mjwebbing.com/news/shoelace-producing-procedure-65146150.html"},{"title":"Shoelaces","url":"https://en.wikipedia.org/wiki/Shoelaces"},{"title":"Aglet","url":"https://en.wikipedia.org/wiki/Aglet"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"shovel","name":"Shovel","kind":"product","category":"hardware","title":"How shovels are made","url":"https://assemblyline.org/make/shovel","stations":7,"upstream":29,"downstream":0,"depth":6,"dek":"On a cheap shovel, the socket that grips the handle is just a tab of the blade rolled into a ring.","answer":"A stamped shovel usually starts as one flat blank of cold-rolled sheet steel, blade and socket together. Presses dish the blade and raise a stiffening rib, the tab is curled into a ring, and a rivet through that ring grips a wooden handle. Forged shovels take a costlier route, hammered from hot steel so the metal thickens where the load falls.","aka":["spade","digging shovel"],"inputs":["sheet-steel","lumber"],"uses":[],"grounds":["timber","zinc-ore","air","iron-ore","limestone","dolomite","water","manganese-ore","natural-gas","sulfur","coal","quartz","crude-oil"],"upstreamSlugs":["sheet-steel","lumber","steel","zinc","timber","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","iron-ore","coke","limestone","dolomite","silicon","propane","water","manganese-ore","natural-gas","sulfur","coal","quartz","charcoal","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Blank the flat sheet","process":"stamp","text":"A press cuts one flat outline from cold-rolled sheet steel, with a long tab above the blade. Whatever gets trimmed away on either side of that tab goes to scrap.","inputs":["sheet-steel"]},{"name":"Dish and rib the scoop","process":"press","text":"Dies curve the blade and raise a standing rib at the back of the dish, which stiffens the thin sheet. The rib leaves a hollow on the underside where mud and clay can collect.","inputs":[]},{"name":"Curl the tab round","process":"press","text":"The tab is rolled into a circle to make the socket. It normally stays unwelded, so nothing holds the ring shut until a rivet goes through it.","inputs":[]},{"name":"Weld on a back plate","process":"weld","text":"Mid-grade shovels get an extra flat plate welded over the hollow on the back. This adds rigidity and leaves a smooth face that soil cannot cake onto.","inputs":["sheet-steel"]},{"name":"Plug the gap","process":"assemble","text":"A piece of wood usually fills the space between the handle's end and the blade. Without it, the thin metal there can collapse when someone levers with the tool.","inputs":["lumber"]},{"name":"Seat the handle","process":"assemble","text":"A wooden handle goes in with its grain lined up vertically for strength. Its end is notched so it can flex to follow the curve of the neck.","inputs":["lumber"]},{"name":"Rivet it through","process":"assemble","text":"A hole drilled through the ring takes a rivet, which locks the handle in and keeps the socket closed.","inputs":[]}],"facts":["In the Neolithic age and earlier, the shoulder blade of a large animal was often used as a crude shovel.","Forged shovel blades are thin at the digging edge and grow thicker toward the handle, a variation stamping cannot match.","Where a stamped socket meets the foot tread there is only a single thickness of sheet, and that spot is a known place for shovels to rip under heavy load."],"where":[],"whereNote":null,"sources":[{"title":"Shovel","url":"https://en.wikipedia.org/wiki/Shovel"},{"title":"US5664820A: Shovel with composite socket and process for manufacturing same","url":"https://patents.google.com/patent/US5664820A/en"},{"title":"Shovel Buying Guide, A.M. Leonard","url":"https://www.amleo.com/shovel-buying-guide"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"silica-sand","name":"Silica sand","kind":"raw","category":"ground","title":"How silica sand is dug","url":"https://assemblyline.org/make/silica-sand","stations":5,"upstream":0,"downstream":146,"depth":0,"dek":"Glass sand may carry no more than 0.03% iron oxide, so plants clean it by rubbing the grains against each other.","answer":"Glass-grade sand gets rubbed clean against itself. Miners quarry sandstone, truck dry sand from pits, or pump wet deposits with a dredge, then screen the grains and churn them in a dense slurry that scours off iron stain. Slimes wash away, flotation can lift out mica and heavy minerals, and the sand is dewatered and dried for glassmakers, potters or oil wells.","aka":["industrial sand","foundry sand","glass sand"],"inputs":[],"uses":["toothpaste","silicone","fiberglass","cast-iron-pan","glass","window-glass","glass-bottle","smartphone-glass","concrete","toilet","insulation","marble-toy","car-engine","phosphoric-acid","golf-club","bell","bronze-statue","floor-tile","stained-glass","pottery","camera-lens"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["toothpaste","silicone","fiberglass","cast-iron-pan","glass","window-glass","glass-bottle","smartphone-glass","concrete","toilet","insulation","marble-toy","car-engine","phosphoric-acid","golf-club","bell","bronze-statue","floor-tile","stained-glass","pottery","camera-lens","shampoo","deodorant","syringe","condom","hearing-aid","solar-panel","contact-lens","airbag","cork-stopper","pressure-cooker","blender","foundation-makeup","eyeshadow","prosthetic-leg","double-glazed-window","remote-control","electric-toothbrush","printed-circuit-board","wind-turbine","surfboard","ski","snowboard","fishing-rod","kite","roof-shingle","vinyl-floor","canoe","sailboat","umbrella","thermometer","lcd-screen","oled-screen","hard-drive","camera-sensor","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","neon-sign","smartwatch","e-reader","mirror","skyscraper","windshield","nail-polish","perfume","penicillin","insulin","vaccine","ketchup","cola","sparkling-water","beer","wine","champagne","whiskey","vodka","gin","rum","tequila","sake","hard-cider","hot-sauce","soda","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","port-wine","prosecco","non-alcoholic-beer","smartphone","dishwasher","car","locomotive","motorcycle","digital-camera","satellite","electric-car","aluminum-window-frame","pacemaker","led-bulb","ev-battery","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","washing-machine","drone","airplane","rocket","elevator","ceiling-fan","treadmill","pinball-machine","smoke-detector","wireless-earbuds","phone-charger","game-console","wifi-router","inkjet-printer","graphics-card","eyeglass-frame","mustard","salsa","pickles","sauerkraut","jam","hazelnut-spread","air-freshener","dish-soap","hairspray","mayonnaise"],"steps":[{"name":"Quarry or pump the deposit","process":"mine","text":"Sandstone is quarried like hard rock, crushed, and rod-milled back to its natural grain size. Dry pits simply load the loose grains into trucks. Deposits below the water table are mined hydraulically with dredge pumps.","inputs":[]},{"name":"Screen off the oversize","process":"separate","text":"Water carries the feed across a vibrating screen, and anything coarser than 20 mesh goes to waste or back to the mill. Cyclones or rake classifiers then pull out excess water.","inputs":[],"spec":"20 mesh"},{"name":"Scour the grains clean","process":"wash","text":"Thick wet feed enters an attrition scrubber, where propellers keep the whole mass in violent motion. Grains grind against one another, which strips off iron stain and stubborn clay. A second set of cyclones carries away the loosened slime.","inputs":[],"spec":"70 to 75% solids"},{"name":"Float out the impurities","process":"separate","text":"Harder deposits go to flotation in an acid pulp. Mica, feldspar and iron-bearing heavy minerals ride the froth to waste, while clean silica leaves the far end of the machine. Some feed meets its specification after scrubbing and skips this step.","inputs":[]},{"name":"Dewater and dry","process":"dry","text":"Dewatering screens or classifiers drain the product to about 15% moisture, since every bit of water left costs fuel at the dryer. Rotary dryers fired by oil or gas finish the job where a dry product is wanted, and frac grades then cross a final sizing screen.","inputs":[]}],"facts":["Quartz is the most common constituent of sand inland and in non-tropical coastal settings, because it is chemically inert and hard enough to resist weathering.","Wind blows desert sand grains round, and round grains will not bind into solid concrete.","Frac sand has to be round and crush-resistant, because its grains prop open fissures in rock so oil and gas can flow out."],"where":[],"whereNote":null,"sources":[{"title":"Silica Sand Processing & Sand Washing Plant Equipment","url":"https://www.911metallurgist.com/blog/silica-sand-processing-sand-washing-plant-equipment/"},{"title":"Frac Sand Wet Processing","url":"https://www.mclanahan.com/blog/frac-sand-wet-processing-key-technologies-for-high-quality-frac-sand"},{"title":"Sand","url":"https://en.wikipedia.org/wiki/Sand"},{"title":"Quartz","url":"https://en.wikipedia.org/wiki/Quartz"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"silicon-wafer","name":"Silicon wafer","kind":"material","category":"electronics","title":"How silicon wafers are made","url":"https://assemblyline.org/make/silicon-wafer","stations":6,"upstream":19,"downstream":33,"depth":6,"dek":"A wafer is sliced from one crystal that can grow two meters long, pulled from a quartz pot used only once.","answer":"A silicon wafer is sliced from a single crystal. Pure polysilicon melts in a quartz crucible, a seed crystal is dipped in and slowly pulled up while turning, and a cylinder called a boule grows. A wire saw slices the boule, then the slices are ground flat, etched to remove damage and polished to a mirror.","aka":["semiconductor wafer","silicon slice","Czochralski silicon"],"inputs":["polysilicon","quartz","argon"],"uses":["microchip","memory-chip","camera-sensor","solar-cell","inkjet-printer"],"grounds":["quartz","air","coal","timber","water","natural-gas","rock-salt","sulfur"],"upstreamSlugs":["polysilicon","quartz","argon","silicon","hydrochloric-acid","trichlorosilane","hydrogen","nitrogen","air","coke","coal","charcoal","timber","chlorine","water","natural-gas","rock-salt","sulfuric-acid","sulfur"],"downstreamSlugs":["microchip","memory-chip","camera-sensor","solar-cell","inkjet-printer","hearing-aid","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","rocket","smartwatch","wireless-earbuds","phone-charger","usb-cable","digital-camera","game-console","wifi-router","e-reader","graphics-card","remote-control","electric-toothbrush","solar-panel","car"],"steps":[{"name":"Melt polysilicon in quartz","process":"melt","text":"Chunks of ultra-pure polysilicon go into a crucible of high-purity quartz and are melted at 1,425 °C. Boron or phosphorus can be added to the melt in exact amounts to set the electrical type of the finished crystal.","inputs":["polysilicon","quartz"],"spec":"1,425 °C"},{"name":"Pull a single crystal","process":"grow","text":"A seed crystal on a rod is dipped into the melt and lifted slowly while it rotates, under argon gas. The melt freezes onto the seed in the same crystal pattern, and temperature and pulling speed set the width.","inputs":["argon"]},{"name":"Saw the boule apart","process":"cut","text":"The finished cylinder can reach two meters in length and weigh several hundred kilograms. A wire saw slices it into thin disks, and the quartz crucible is usually thrown away after one ingot.","inputs":[]},{"name":"Grind the slices flat","process":"grind","text":"Sawing leaves ripples and a damaged surface, so each disk is machined to improve flatness.","inputs":[]},{"name":"Etch off the damage","process":"etch","text":"A chemical bath dissolves the crystal damage left behind by sawing and grinding.","inputs":[]},{"name":"Polish to a mirror","process":"grind","text":"A final polish leaves a surface flat enough to hold circuit patterns only nanometers wide.","inputs":[]}],"facts":["The quartz crucible is normally thrown away after a single ingot has been pulled from it.","Moving from 200 mm to 300 mm wafers cut the price per die by about 30 to 40%.","Wafer-grade silicon is nearly defect-free single crystal with a purity of 99.9999999% or higher."],"where":[],"whereNote":null,"sources":[{"title":"Wafer (electronics)","url":"https://en.wikipedia.org/wiki/Wafer_%28electronics%29"},{"title":"Czochralski method","url":"https://en.wikipedia.org/wiki/Czochralski_method"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"silicone","name":"Silicone","kind":"material","category":"plastics","title":"How silicone is made","url":"https://assemblyline.org/make/silicone","stations":6,"upstream":17,"downstream":22,"depth":4,"dek":"Silicone is a chain of silicon and oxygen atoms dressed in carbon groups, and it is made from sand.","answer":"Silicone is made from metallurgical silicon, which is ground and reacted with methyl chloride to form chlorosilanes. These liquids are distilled apart and mixed with water, which links them into silicon-oxygen chains. Chain length decides whether the product is an oil, a grease, a rubber or a resin, and fillers and curing finish the job.","aka":["polysiloxane","silicone rubber","silicone oil"],"inputs":["silicon","methanol","hydrochloric-acid","water","silica-sand"],"uses":["shampoo","deodorant","syringe","condom","hearing-aid","solar-panel","contact-lens","airbag","cork-stopper","pressure-cooker","blender","foundation-makeup","eyeshadow","prosthetic-leg","double-glazed-window","remote-control","electric-toothbrush"],"grounds":["water","silica-sand","quartz","coal","timber","natural-gas","rock-salt","sulfur","air"],"upstreamSlugs":["silicon","methanol","hydrochloric-acid","water","silica-sand","quartz","coke","coal","charcoal","timber","natural-gas","chlorine","hydrogen","rock-salt","sulfuric-acid","sulfur","air"],"downstreamSlugs":["shampoo","deodorant","syringe","condom","hearing-aid","solar-panel","contact-lens","airbag","cork-stopper","pressure-cooker","blender","foundation-makeup","eyeshadow","prosthetic-leg","double-glazed-window","remote-control","electric-toothbrush","satellite","car","electric-car","champagne","aluminum-window-frame"],"steps":[{"name":"Start from silicon metal","process":"crush","text":"Metallurgical silicon, smelted from quartz sand, is ground to a fine powder. The fine grains give the next reaction plenty of surface.","inputs":["silicon"]},{"name":"React it with methyl chloride","process":"react","text":"In a fluidized bed, the silicon powder is lifted on a stream of methyl chloride gas with a copper catalyst. The result is a mix of methylchlorosilane liquids, with dimethyldichlorosilane the main one. Methyl chloride is made commercially from methanol and hydrochloric acid.","inputs":["methanol","hydrochloric-acid"]},{"name":"Distill the chlorosilanes","process":"refine","text":"Tall columns separate the near-identical liquids by their boiling points. Purity at this stage decides how long the chains can grow.","inputs":[]},{"name":"Hydrolyze with water","process":"react","text":"The purified liquid meets water, and hydrochloric acid is released. What is left forms silicon-oxygen rings and short chains, called siloxanes.","inputs":["water"]},{"name":"Grow the chains","process":"react","text":"Catalysts link the siloxanes into long chains. Short chains make oils and long chains make gums, and the length is set to match the product.","inputs":[]},{"name":"Fill and cure into rubber","process":"knead","text":"For rubber, the gum is worked with fine silica filler and a curing agent, then molded or extruded and heated. The chains cross-link into a flexible solid that stays soft in the cold and the heat.","inputs":["silica-sand"]}],"facts":["Frederic Kipping coined the word silicone in 1901 and is called the father of silicones, credited with launching the industry in the 1930s.","Silicones have an inorganic backbone of silicon and oxygen but behave like organic polymers."],"where":[],"whereNote":null,"sources":[{"title":"Silicone","url":"https://en.wikipedia.org/wiki/Silicone"},{"title":"Polymerization","url":"https://en.wikipedia.org/wiki/Polymerization"},{"title":"Chloromethane","url":"https://en.wikipedia.org/wiki/Chloromethane"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"silk","name":"Silk","kind":"material","category":"textiles","title":"How silk is made","url":"https://assemblyline.org/make/silk","stations":6,"upstream":6,"downstream":2,"depth":3,"dek":"One silkworm cocoon is a single unbroken thread, which is reeled off in one piece rather than spun.","answer":"Silkworms fed on mulberry leaves spin cocoons from one continuous protein filament held together by a gum called sericin. Producers drop the cocoons in hot water, which dissolves the gum and kills the pupa, then reel the filament off in one length. Several filaments are twisted into thread and woven.","aka":["raw silk","mulberry silk","silk thread"],"inputs":["silk-cocoons","water","hydrogen-peroxide"],"uses":["silk-tie","winter-gloves"],"grounds":["silk-cocoons","water","air","natural-gas"],"upstreamSlugs":["silk-cocoons","water","hydrogen-peroxide","hydrogen","air","natural-gas"],"downstreamSlugs":["silk-tie","winter-gloves"],"steps":[{"name":"Feed the silkworms","process":"grow","text":"Silkworms eat mulberry leaves until, after the fourth molt, they climb a twig and spin a cocoon. A producer needs about 104 kg of leaves eaten by 3000 worms to get 1 kg of silk.","inputs":["silk-cocoons"]},{"name":"Boil the cocoons","process":"cook","text":"Cocoons go into hot or boiling water. It softens the sericin that cements the filaments together, which frees the end of the thread, and it kills the pupa before the moth can chew out and break the filament.","inputs":["water"]},{"name":"Reel off the filament","process":"draw","text":"The loose end is found and the filament is unwound in one continuous length. Silk is not spun like cotton or wool, because it is already a long fiber.","inputs":[]},{"name":"Dry and pack the raw silk","process":"dry","text":"After drying, the raw silk is graded and packed according to quality, ready for the loom.","inputs":[]},{"name":"Twist into thread","process":"spin","text":"Several single filaments are combined and twisted, a step called throwing. The amount and direction of twist decides what kind of yarn comes out, and threads may be plied together.","inputs":[]},{"name":"Weave and dye","process":"weave","text":"Mills weave the thread into fabric and then dye it. Producers in Thailand bleach their yellow silk in tubs of hydrogen peroxide before dyeing.","inputs":["hydrogen-peroxide"]}],"facts":["About 5000 silkworms are needed to make one pure silk kimono.","The earliest evidence of silk is the protein fibroin in soil from two tombs at Jiahu in Henan, about 8,500 years old.","Silk is about 75 to 80 percent fibroin, coated in 20 to 25 percent sericin."],"where":[],"whereNote":null,"sources":[{"title":"Silk","url":"https://en.wikipedia.org/wiki/Silk"},{"title":"Sericulture","url":"https://en.wikipedia.org/wiki/Sericulture"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"silk-cocoons","name":"Silk cocoons","kind":"raw","category":"farm","title":"How silk cocoons are raised","url":"https://assemblyline.org/make/silk-cocoons","stations":4,"upstream":0,"downstream":3,"depth":0,"dek":"A single cocoon is one unbroken thread, and it takes about 5000 silkworms to make enough for a silk kimono.","answer":"Silk cocoons come from caterpillars of the mulberry silkmoth, raised indoors on a diet of mulberry leaves. After several moults each caterpillar climbs onto a twig and spins a cocoon from one continuous filament of silk protein. The farmer collects the cocoons before the moths can chew their way out.","aka":["sericulture","silkworm cocoons","silk farming","mulberry silk"],"inputs":[],"uses":["silk"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["silk","silk-tie","winter-gloves"],"steps":[{"name":"Hatch the eggs","process":"grow","text":"A female silkmoth lays 300 to 500 eggs. They hatch into tiny caterpillars, the silkworms, which are kept in trays and begin eating almost at once.","inputs":[]},{"name":"Feed on mulberry leaves","process":"grow","text":"Farmers feed the silkworms mulberry leaves, and the worms grow quickly through several moults. To make 1 kg of silk, 3000 silkworms must eat 104 kg of leaves.","inputs":[],"spec":"104 kg of leaves per 1 kg of silk"},{"name":"Let them spin cocoons","process":"grow","text":"After the fourth moult each worm climbs a twig placed nearby and spins its cocoon. The thread comes from two glands in the head and is one continuous filament, made of the protein fibroin and glued with a gum called sericin.","inputs":[]},{"name":"Collect the cocoons","process":"harvest","text":"The cocoons are gathered while the pupae are still inside. Keeping the cocoon intact is what allows the filament to be unwound later as one unbroken length.","inputs":[]}],"facts":["It takes about 5000 silkworms to make enough silk for a pure silk kimono.","Silk is reeled, not spun: the cocoon's filament comes off in one continuous length.","A ceramic piece shaped like a silkworm, found in Hebei and dated to about 5400 years ago, is the earliest known evidence of sericulture."],"where":[{"place":"China","share":"54% of silk produced"},{"place":"India","share":"14%"}],"whereNote":"Share of world silk production as given in the Wikipedia silk article (no year given).","sources":[{"title":"Silk","url":"https://en.wikipedia.org/wiki/Silk"},{"title":"Sericulture","url":"https://en.wikipedia.org/wiki/Sericulture"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"silk-tie","name":"Silk tie","kind":"product","category":"textiles","title":"How silk ties are made","url":"https://assemblyline.org/make/silk-tie","stations":7,"upstream":25,"downstream":0,"depth":8,"dek":"Most good ties are cut at 45 degrees to the weave so they hang straight, which is why their stripes run slanted.","answer":"A silk tie is cut from woven silk at 45 degrees to the grain, known as on the bias, so the finished tie falls from the knot without twisting. Three pieces are sewn end to end, a wool lining is laid inside, and the cloth is folded around it and hand or machine slip-stitched along the back.","aka":["necktie","silk necktie"],"inputs":["silk","thread","wool-yarn"],"uses":[],"grounds":["silk-cocoons","water","fleece","air","natural-gas","crude-oil","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["silk","thread","wool-yarn","silk-cocoons","water","hydrogen-peroxide","polyester","fleece","hydrogen","air","pet-plastic","natural-gas","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","crude-oil","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Reel and twist the silk","process":"spin","text":"Threads are unwound from silkworm cocoons and twisted together into yarn. Silk is strong, takes dye well, and has a sheen that polyester imitates only partly.","inputs":["silk"]},{"name":"Weave and dye the cloth","process":"weave","text":"Looms weave stripes, twills or woven patterns, or a plain cloth is printed afterward. The yarn is dyed before weaving or the finished cloth is dyed or printed.","inputs":[]},{"name":"Cut across the grain","process":"cut","text":"Stacks of 40 to 50 sheets are hand cut at Drake's, with two ties to a block, and machines do the same work elsewhere. Pieces come off at 45 degrees to the weave, so any stripe ends up running at a slant.","inputs":[]},{"name":"Join three segments","process":"sew","text":"A tie is sewn from three pieces, each cut on the bias: two long ends and a shorter piece for the neck. The seams run diagonally across the cloth, where the tie is folded under or tucked behind the knot.","inputs":["thread"]},{"name":"Insert the wool lining","process":"laminate","text":"A soft inner layer of wool is laid inside the silk. It gives the tie its body and spring, and the gold bars on it show the weight of the wool.","inputs":["wool-yarn"]},{"name":"Fold and slip-stitch","process":"sew","text":"The edges are folded around the interlining and closed with a long, loose stitch down the back. The stitch is left slack on purpose, so the tie can stretch when pulled and spring back afterward.","inputs":["thread"]},{"name":"Press and label","process":"press","text":"Steam presses the tie flat, edges are tacked down, and a label is sewn in the back. Finished ties are folded or rolled for packing.","inputs":[]}],"facts":["Before the diagonal cut, ties tended to curl to one side once tied. The American tailor Jesse Langsdorf patented his fix in 1924.","A seven-fold tie has no lining, only silk folded seven times and sewn by hand, which is why it is so expensive."],"where":[],"whereNote":null,"sources":[{"title":"Necktie","url":"https://en.wikipedia.org/wiki/Necktie"},{"title":"A closer look at the necktie (Christian Science Monitor)","url":"https://www.csmonitor.com/2004/0615/p18s02-hfks.html"},{"title":"Hand cutting ties at Drake's (Permanent Style)","url":"https://www.permanentstyle.com/2009/11/hand-cutting-ties-at-drakes.html"},{"title":"Tie manufacture (Ben Silver)","url":"https://www.bensilver.com/Tie-Manufacture.dlp"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"silver","name":"Silver","kind":"material","category":"metals","title":"How silver is made","url":"https://assemblyline.org/make/silver","stations":6,"upstream":11,"downstream":63,"depth":3,"dek":"Most silver is not mined for itself. It rides along inside lead, zinc, copper and gold ores.","answer":"Most silver is recovered as a byproduct of mining lead, zinc, copper and gold. It travels with those metals through concentration and smelting. It is then separated, for example by zinc in the Parkes process for lead, or from the anode slime left in copper refineries, and purified by electrolysis to over 99.9 percent.","aka":["fine silver","refined silver","silver bullion"],"inputs":["silver-ore","lead-ore","zinc-ore","copper-ore","zinc","sulfuric-acid","lime"],"uses":["solar-cell","solder","coin","gold-ring","mirror","trumpet","thermos","flute","saxophone","medal","light-switch","smoke-detector","vinyl-record"],"grounds":["silver-ore","lead-ore","zinc-ore","copper-ore","air","sulfur","water","limestone"],"upstreamSlugs":["silver-ore","lead-ore","zinc-ore","copper-ore","zinc","sulfuric-acid","lime","air","sulfur","water","limestone"],"downstreamSlugs":["solar-cell","solder","coin","gold-ring","mirror","trumpet","thermos","flute","saxophone","medal","light-switch","smoke-detector","vinyl-record","solar-panel","hearing-aid","pacemaker","printed-circuit-board","led-bulb","solid-state-drive","refrigerator","drone","electric-guitar","air-conditioner","stained-glass","eyeglass-frame","smartwatch","wireless-earbuds","phone-charger","usb-cable","microphone","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","satellite","thermometer","ev-battery","smartphone","laptop","television","hard-drive","computer-keyboard","computer-mouse","wind-turbine","microwave-oven","washing-machine","car","electric-car","airbag","airplane","rocket","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","digital-camera","e-reader","skyscraper"],"steps":[{"name":"Mine the base-metal ore","process":"mine","text":"Silver minerals such as acanthite occur in veins and in ore bodies that are mainly lead, zinc or copper. The silver is a modest passenger in rock mined for another metal.","inputs":["silver-ore","lead-ore","zinc-ore","copper-ore"]},{"name":"Float it with the sulfides","process":"separate","text":"Crushed ore is floated to a concentrate. Silver follows the main metal, so the concentrate of copper or lead is also the concentrate of silver.","inputs":[]},{"name":"Smelt it with its host metal","process":"melt","text":"Smelting turns the concentrate into metal, and the silver stays dissolved in it. Lead bullion from ore that also contains silver carries it along.","inputs":[]},{"name":"Strip it out of the host metal","process":"separate","text":"For lead, zinc is added in the Parkes process and the silver dissolves into it. For copper, the silver is not plated onto the cathode, and it collects in a sludge below the anode, called anode slime.","inputs":["zinc"]},{"name":"Clean it of base metals","process":"refine","text":"The silver-rich slime or zinc crust is treated with hot dilute sulfuric acid and aeration, then smelted with a lime or silica flux to drive off the remaining base metals.","inputs":["sulfuric-acid","lime"]},{"name":"Electrolyze to fine silver","process":"electrolyze","text":"The final purification is electrolysis in a silver nitrate solution. This gives silver of over 99.9 percent purity, and higher grades above 99.999 percent are also made.","inputs":[]}],"facts":["Silver has the highest electrical conductivity, thermal conductivity and reflectivity of any metal.","Argentina took its name from the Latin word for silver, argentum.","Pure silver is too soft for most uses, so coins and tableware are alloyed with copper, with sterling at 925 parts per 1000."],"where":[{"place":"Mexico","share":"6,300 tonnes"},{"place":"Peru","share":"3,600 tonnes"},{"place":"China","share":"3,400 tonnes"},{"place":"Bolivia","share":"1,500 tonnes"},{"place":"Chile","share":"1,400 tonnes"}],"whereNote":"2025, silver mine production, out of about 26,000 tonnes worldwide.","sources":[{"title":"Silver","url":"https://en.wikipedia.org/wiki/Silver"},{"title":"Electrorefining","url":"https://en.wikipedia.org/wiki/Electrorefining"},{"title":"Lead","url":"https://en.wikipedia.org/wiki/Lead"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"silver-ore","name":"Silver ore","kind":"raw","category":"ground","title":"How silver ore is mined","url":"https://assemblyline.org/make/silver-ore","stations":4,"upstream":0,"downstream":64,"depth":0,"dek":"Most silver is a side effect of mining something else, usually lead or copper.","answer":"Silver rarely appears in pure form, so it is mostly recovered alongside lead, copper and zinc. The ore is crushed to powder, floated in frothing tanks to concentrate the metal-bearing minerals, and then treated chemically with a cyanide solution to pull out the silver. Some mines are dedicated silver mines.","aka":["argentite"],"inputs":[],"uses":["silver"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["silver","solar-cell","solder","coin","gold-ring","mirror","trumpet","thermos","flute","saxophone","medal","light-switch","smoke-detector","vinyl-record","solar-panel","hearing-aid","pacemaker","printed-circuit-board","led-bulb","solid-state-drive","refrigerator","drone","electric-guitar","air-conditioner","stained-glass","eyeglass-frame","smartwatch","wireless-earbuds","phone-charger","usb-cable","microphone","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","satellite","thermometer","ev-battery","smartphone","laptop","television","hard-drive","computer-keyboard","computer-mouse","wind-turbine","microwave-oven","washing-machine","car","electric-car","airbag","airplane","rocket","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","digital-camera","e-reader","skyscraper"],"steps":[{"name":"Mine the mixed ore","process":"mine","text":"Silver-bearing ore holds very little silver and much more copper and lead. Silver turns up inside chalcopyrite and galena, and only rarely as native nuggets, in placer deposits and in veins.","inputs":[]},{"name":"Crush to powder","process":"crush","text":"The ore is ground fine so that individual grains are exposed to the chemicals that come next.","inputs":[]},{"name":"Float the sulfides","process":"separate","text":"Where silver rides along with lead and copper, froth flotation lifts the metal-bearing grains out of the waste rock. The concentrate then goes to a leach, or sometimes to a smelter first.","inputs":[]},{"name":"Leach out the silver","process":"wash","text":"After flotation, silver is extracted with a cyanide process similar to the one used for gold. Sometimes the concentrate is smelted before the cyanide treatment.","inputs":[]}],"facts":["Silver mining goes back to about 3,000 BC in Anatolia.","Some galena carries up to 0.5% silver, so lead mines can end up earning more from silver.","Silver is also made as a by-product of the electrolytic refining of copper."],"where":[{"place":"Mexico","share":"18.7% of world output, 5,000 metric tons"}],"whereNote":"Silver mined in 2014, out of 26,800 tonnes worldwide; the Wikipedia article gives no newer ranking.","sources":[{"title":"Silver mining","url":"https://en.wikipedia.org/wiki/Silver_mining"},{"title":"Silver","url":"https://en.wikipedia.org/wiki/Silver"},{"title":"Galena","url":"https://en.wikipedia.org/wiki/Galena"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"skateboard","name":"Skateboard","kind":"product","category":"play","title":"How skateboards are made","url":"https://assemblyline.org/make/skateboard","stations":8,"upstream":72,"downstream":0,"depth":8,"dek":"A skateboard deck is seven or eight thin sheets of maple glued crosswise and squeezed into a curve.","answer":"A skateboard deck is plywood: seven or eight thin maple veneers, each glued to the next with the grain set at right angles. The stack is pressed in a curved mold until the glue cures. The blank is then cut to shape, sanded and printed, and fitted with metal trucks and urethane wheels.","aka":["skate deck","complete skateboard"],"inputs":["timber","adhesive","ink","polyurethane","aluminum","steel","ball-bearing"],"uses":[],"grounds":["timber","water","crude-oil","coal","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","bauxite","limestone","dolomite","manganese-ore","natural-gas","quartz","zinc-ore","sugar-beet"],"upstreamSlugs":["timber","adhesive","ink","polyurethane","aluminum","steel","ball-bearing","polyethylene","acrylic","epoxy","paraffin-wax","water","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","propylene","nitric-acid","chlorine","crude-oil","coal","petroleum-coke","alumina","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","steel-wire","sheet-steel","ethylene","ammonia","sulfuric-acid","methanol","phenol","acetone","caustic-soda","hydrogen","soybeans","rapeseed","hexane","clay","formaldehyde","air","titanium-ore","coke","iron-ore","sulfur","corn","sugarcane","yeast","naphtha","rock-salt","bauxite","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","zinc","benzene","molasses","quartz","charcoal","zinc-ore","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Peel the maple veneers","process":"cut","text":"Maple logs are steamed and peeled into thin sheets, which are dried flat. Hard maple is chosen because it is tough and springy.","inputs":["timber"]},{"name":"Glue them crosswise","process":"laminate","text":"Each sheet is coated with glue and stacked with its grain at right angles to the sheets on both sides. Cross-graining makes plywood strong in every direction and resists warping.","inputs":["adhesive"]},{"name":"Press the concave shape","process":"press","text":"The glued stack goes between molds that bend in the concave dish and the curled nose and tail. Pressure holds it until the glue sets.","inputs":[]},{"name":"Saw the outline","process":"machine","text":"The pressed blank is cut to the board shape, then the edges are rounded and the truck holes drilled.","inputs":[]},{"name":"Print the graphic","process":"print","text":"Art goes on the underside, and the top gets a coat of finish. Rough grip tape covers the riding surface.","inputs":["ink"]},{"name":"Cast the urethane wheels","process":"cast","text":"Liquid polyurethane is poured into wheel molds. Harder grades roll more smoothly and last longer, while softer ones grip better and cost less.","inputs":["polyurethane"]},{"name":"Cast the trucks","process":"cast","text":"Each truck is a hanger that holds the axle and a baseplate that bolts to the deck. They are joined by a kingpin, which lets the truck swivel when the rider leans.","inputs":["aluminum","steel"]},{"name":"Bolt on trucks and wheels","process":"assemble","text":"Bearings go into the wheels, and the wheels onto the axles. The trucks are bolted to the deck.","inputs":["ball-bearing"]}],"facts":["Skateboarding began in the late 1940s or early 1950s, when Californian surfers wanted something to do when the waves were flat.","Skateboard wheels range from around 48 mm to around 60 mm across."],"where":[],"whereNote":null,"sources":[{"title":"Skateboard","url":"https://en.wikipedia.org/wiki/Skateboard"},{"title":"Plywood","url":"https://en.wikipedia.org/wiki/Plywood"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ski","name":"Ski","kind":"product","category":"play","title":"How skis are made","url":"https://assemblyline.org/make/ski","stations":8,"upstream":77,"downstream":0,"depth":8,"dek":"A ski is a hot-pressed sandwich of plastic, glass, steel and wood, and 40 percent of its core wood ends up as sawdust.","answer":"A ski is built in layers. Workers lay a plastic base, fiberglass, steel edges, metal reinforcement and a shaped wooden core into a mold, add a printed top sheet, and close it in a heated press. The resin bonds everything into one stiff, springy plank. Trimming, base grinding and a flex test finish the pair.","aka":["alpine skis","downhill skis","cross-country skis"],"inputs":["lumber","adhesive","ink","polyethylene","fiberglass","steel","aluminum","rubber","epoxy"],"uses":[],"grounds":["timber","water","silica-sand","limestone","crude-oil","coal","natural-latex","sulfur","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","corn","sugarcane","natural-gas","rock-salt","trona","dolomite","manganese-ore","bauxite","quartz","sugar-beet"],"upstreamSlugs":["lumber","adhesive","ink","polyethylene","fiberglass","steel","aluminum","rubber","epoxy","timber","acrylic","polyurethane","paraffin-wax","water","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","ethylene","silica-sand","limestone","soda-ash","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","crude-oil","coal","petroleum-coke","alumina","natural-latex","synthetic-rubber","sulfur","phenol","propylene","acetone","chlorine","caustic-soda","ammonia","sulfuric-acid","methanol","nitric-acid","hydrogen","soybeans","rapeseed","hexane","clay","formaldehyde","air","titanium-ore","coke","iron-ore","corn","sugarcane","yeast","naphtha","natural-gas","rock-salt","carbon-dioxide","trona","dolomite","silicon","propane","manganese-ore","bauxite","benzene","styrene","molasses","quartz","charcoal","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Glue up the wood core","process":"laminate","text":"Two wedges of wood are glued together to form one core blank. Atomic's Austrian factory uses laminated ash, beech and poplar from nearby forests, chosen for strength that lasts.","inputs":["lumber","adhesive"]},{"name":"Mill the core to shape","process":"machine","text":"Robots and CNC stations cut the blank to the outline of a ski, thick under the boot and thin at the tip and tail. Workers then shave, grind and fit the reinforcement by hand. About 40 percent of the wood ends up as sawdust, which the factory recycles into chipboard.","inputs":[]},{"name":"Print the top sheet","process":"print","text":"Graphics go onto the top layer by digital, sublimation or screen printing. Sublimation prints the design on paper first and then transfers it, which suits many colors, while screen printing suits designs with just a few.","inputs":["ink"]},{"name":"Stack the layers in the mold","process":"assemble","text":"A worker builds each ski by hand, base first, then fiberglass, steel edges, a layer of aluminum alloy and rubber strips along the sides, wetting the layers with epoxy resin. The wood core goes in next, followed by more rubber, fiberglass and metal, and the top sheet last. One worker assembles 50 to 60 skis a day, and the mold has to be cleaned between each, since any residue can spoil a ski.","inputs":["polyethylene","fiberglass","steel","aluminum","rubber","epoxy"]},{"name":"Press under heat","process":"mold","text":"The whole stack needs strong pressure and heat to bond. Atomic's ski presses run on heat piped in from a wood-chip power plant next door. When the ski comes out, excess resin has squeezed out around the edges.","inputs":[]},{"name":"Trim the overhang","process":"cut","text":"Material hangs over the edge of the pressed ski and the base is smeared with spilled epoxy. The ski is cleaned and clamped into a separate machine that cuts the overhang away.","inputs":[]},{"name":"Grind the base","process":"grind","text":"Stones grind the base flat and cut a fine texture into it that helps it glide. Today most of this is automated, but at Atomic the ski tip is still ground by hand, in a shower of sparks.","inputs":[]},{"name":"Bend and match each pair","process":"inspect","text":"An inspector flexes every ski by hand and pairs it with another that bends the same way. A stylus drawn along the base checks that the ground texture is even.","inputs":[]}],"facts":["Skis predate the wheel. The oldest wooden skis found, from Russia, Sweden and Norway, are thousands of years old.","Steel edges were invented in 1928 in Austria, long before they became standard on every ski.","A single ski carries a QR code that lets the factory trace who assembled it and when."],"where":[],"whereNote":null,"sources":[{"title":"Ski","url":"https://en.wikipedia.org/wiki/Ski"},{"title":"Inside the Atomic ski factory","url":"https://www.amersports.com/newsroom/inside-the-atomic-ski-factory-the-making-of-a-perfect-pair-for-powder/"},{"title":"How Atomic skis are made","url":"https://fasterskier.com/2009/03/how-atomic-skis-are-made/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"skyscraper","name":"Skyscraper","kind":"product","category":"minerals","title":"How skyscrapers are built","url":"https://assemblyline.org/make/skyscraper","stations":6,"upstream":88,"downstream":0,"depth":10,"dek":"A skyscraper's glass walls carry no weight at all. The frame inside holds everything up.","answer":"A skyscraper is built from the ground up in this order: deep foundations, a steel or reinforced-concrete frame, then a non-structural curtain wall hung on the outside. Elevators and mass dampers go in last. The frame carries the weight, and the wind is usually the largest force that engineers must design against.","aka":["high-rise","tall building","tower"],"inputs":["concrete","rebar","steel-beam","aluminum","window-glass","elevator"],"uses":[],"grounds":["gravel","silica-sand","water","crude-oil","coal","limestone","dolomite","clay","gypsum","zinc-ore","air","bauxite","rock-salt","trona","tin-ore","natural-gas","iron-ore","manganese-ore","sulfur","corn","chromite","nickel-ore","copper-ore","quartz","timber","lead-ore","silver-ore","sugarcane","sugar-beet"],"upstreamSlugs":["concrete","rebar","steel-beam","aluminum","window-glass","elevator","gravel","silica-sand","cement","water","steel","steel-scrap","zinc","epoxy","crude-oil","coal","petroleum-coke","alumina","soda-ash","limestone","dolomite","tin","nitrogen","hydrogen","wire-rope","sheet-steel","stainless-steel","electric-motor","ball-bearing","printed-circuit-board","copper-wire","clay","gypsum","pig-iron","magnesium","oxygen","lime","manganese","argon","propane","zinc-ore","air","sulfuric-acid","phenol","propylene","acetone","chlorine","caustic-soda","bauxite","rock-salt","ammonia","carbon-dioxide","trona","tin-ore","coke","natural-gas","steel-wire","chromium","nickel","copper","fiberglass","photoresist","solder","iron-ore","silicon","manganese-ore","sulfur","benzene","naphtha","corn","yeast","chromite","nickel-ore","copper-ore","phenolic-resin","lead","silver","quartz","charcoal","timber","toluene","molasses","formaldehyde","lead-ore","silver-ore","sugarcane","sugar-beet","methanol"],"downstreamSlugs":[],"steps":[{"name":"Sink deep foundations","process":"drill","text":"Drilled shafts are bored and filled with concrete and steel reinforcement. Other foundations use piles of wood, reinforced concrete or steel driven by a pile driver. A deep foundation carries the building loads down to firm ground.","inputs":["concrete","rebar"]},{"name":"Raise the frame","process":"weld","text":"Modern skyscrapers are built on steel or reinforced concrete frameworks. A steel frame is joined from beams, riveted in the old days, while concrete floors and cores are poured in place.","inputs":["steel-beam","concrete"]},{"name":"Tie it into a tube","process":"weld","text":"Since the early 1960s, tall buildings have used a tube design, with closely spaced perimeter columns and braced frames acting like a hollow tube against wind. This lets towers rise higher using less steel.","inputs":[]},{"name":"Hang the glass skin","process":"assemble","text":"Curtain walls are non-structural exterior walls that carry only their own weight. Aluminum extrusions form the frame, glass is the usual infill, and unitized panels are built in a factory and craned into place.","inputs":["aluminum","window-glass"]},{"name":"Install the elevators","process":"assemble","text":"Elevators are characteristic of skyscrapers. Elisha Otis introduced the safety elevator in 1852, which made upper floors practical to reach.","inputs":["elevator"]},{"name":"Add the dampers","process":"assemble","text":"Mass dampers reduce vibration and swaying in the wind. Gaps in the structure also let air pass through, reducing wind shear.","inputs":[]}],"facts":["The 10-story Home Insurance Building in Chicago, completed in 1885 at 42 m, is widely considered the first steel-frame skyscraper.","The Willis Tower uses a third less steel than the Empire State Building."],"where":[],"whereNote":null,"sources":[{"title":"Skyscraper","url":"https://en.wikipedia.org/wiki/Skyscraper"},{"title":"Curtain wall","url":"https://en.wikipedia.org/wiki/Curtain_wall_%28architecture%29"},{"title":"Deep foundation","url":"https://en.wikipedia.org/wiki/Deep_foundation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"slinky","name":"Slinky","kind":"product","category":"play","title":"How Slinkys are made","url":"https://assemblyline.org/make/slinky","stations":5,"upstream":26,"downstream":0,"depth":6,"dek":"A Slinky wraps 62 feet of flattened steel wire around a spindle about 80 times, then pops out every 15 seconds.","answer":"A Slinky is one long ribbon of spring steel. Round wire comes in on huge spools, passes through a flattener, and winds around a spindle into a coil. Each end is crimped for safety, and the finished coils tumble off a conveyor into boxes. The flattener and coiler were designed by the toy's inventor.","aka":["slinky toy","walking spring"],"inputs":["steel-wire"],"uses":[],"grounds":["iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","coal","quartz","timber","crude-oil","sulfur"],"upstreamSlugs":["steel-wire","steel","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","coal","quartz","charcoal","timber","crude-oil","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Unspool the steel wire","process":"roll","text":"Galvanized spring steel wire comes in on spools of 2,000 pounds each. Spring steel is chosen because once wound, it doesn't unwind.","inputs":["steel-wire"]},{"name":"Flatten the wire","process":"roll","text":"The round wire is fed through a flattener at 12 miles an hour. It leaves as a thin flat ribbon, which gives the coil its smooth edges.","inputs":[]},{"name":"Coil it on a spindle","process":"spin","text":"A coiling unit wraps about 62 feet of ribbon around a spindle about 80 times, and spits out a finished Slinky every 15 seconds. The original from 1945 stood 2 and a half inches tall and had 98 coils.","inputs":[],"spec":"62 feet of wire, about 80 turns"},{"name":"Crimp both ends","process":"stamp","text":"A band is crimped around each end of the coil so the sharp wire end cannot jab a child. This step began in 1973.","inputs":[]},{"name":"Drop into the box","process":"package","text":"Finished Slinkys travel single file along a conveyor. At the end of the belt each one does a somersault, its first step, and is pushed into a box that is sealed automatically.","inputs":[]}],"facts":["The Slinky was born in 1943 when a naval engineer watched a tension spring fall off a shelf and keep walking.","All 400 of the first Slinkys sold in 90 minutes at a Philadelphia department store in 1945.","Soldiers used metal Slinkys as portable radio antennas in the Vietnam War."],"where":[],"whereNote":null,"sources":[{"title":"Unwinding the long history of the Slinky","url":"https://www.nbcnews.com/news/amp/wbna24649304"},{"title":"Slinky","url":"https://en.wikipedia.org/wiki/Slinky"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"smartphone","name":"Smartphone","kind":"product","category":"electronics","title":"How smartphones are made","url":"https://assemblyline.org/make/smartphone","stations":6,"upstream":94,"downstream":0,"depth":10,"dek":"Inside a phone, a barometer, gyroscope, accelerometer and magnetometer ride on the same board as the processor.","answer":"A smartphone is assembled around a printed circuit board carrying the processor, memory and sensors. A glass touchscreen display and a lithium-ion battery attach to a metal or plastic frame. Camera modules, antennas and buttons go in, the case is closed, and software is loaded and tested before packing.","aka":["mobile phone","cell phone","iPhone","Android phone"],"inputs":["printed-circuit-board","microchip","memory-chip","camera-sensor","oled-screen","smartphone-glass","lithium-ion-cell","aluminum"],"uses":[],"grounds":["silica-sand","potash","crude-oil","coal","copper-ore","water","air","limestone","quartz","tin-ore","gold-ore","bauxite","rock-salt","trona","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","iron-ore","natural-gas","sulfur","lead-ore","silver-ore","zinc-ore","corn","dolomite","timber","sugarcane","sugar-beet"],"upstreamSlugs":["printed-circuit-board","microchip","memory-chip","camera-sensor","oled-screen","smartphone-glass","lithium-ion-cell","aluminum","copper","fiberglass","epoxy","photoresist","solder","silicon-wafer","oxygen","tin","gold","nitrogen","glass","indium-tin-oxide","silica-sand","alumina","soda-ash","potash","lithium-carbonate","cobalt","nickel","manganese","synthetic-graphite","polyethylene","steel","crude-oil","coal","petroleum-coke","copper-ore","water","air","sulfuric-acid","limestone","phenol","propylene","acetone","chlorine","caustic-soda","phenolic-resin","lead","silver","polysilicon","quartz","argon","tin-ore","coke","gold-ore","lime","zinc","indium","bauxite","rock-salt","ammonia","carbon-dioxide","trona","lithium-brine","spodumene","cobalt-ore","nickel-ore","manganese-ore","iron-ore","natural-gas","ethylene","pig-iron","magnesium","steel-scrap","sulfur","benzene","naphtha","formaldehyde","lead-ore","silver-ore","zinc-ore","silicon","hydrochloric-acid","trichlorosilane","hydrogen","corn","yeast","dolomite","propane","toluene","methanol","charcoal","timber","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Populate the main board","process":"assemble","text":"Machines place the processor, memory chips and many tiny parts on the main board, and a reflow oven solders them all in one pass.","inputs":["printed-circuit-board","microchip","memory-chip"]},{"name":"Add the sensors and camera","process":"assemble","text":"Accelerometers, gyroscopes, barometers and magnetometers sit on the board or on small modules, along with a CMOS image sensor behind the camera lens.","inputs":["camera-sensor"]},{"name":"Bond the display stack","process":"laminate","text":"The screen panel, a capacitive touch layer and the cover glass are glued into one stack.","inputs":["oled-screen","smartphone-glass"]},{"name":"Seat the battery","process":"assemble","text":"A flat lithium-ion polymer pouch cell goes into the case beside the board.","inputs":["lithium-ion-cell"]},{"name":"Close the frame","process":"assemble","text":"The board, battery and display are fixed into a frame, and the back is sealed.","inputs":["aluminum"]},{"name":"Load software and test","process":"inspect","text":"Operating software is loaded and the phone runs through automated checks of screen, radios, camera and buttons before it is boxed.","inputs":[]}],"facts":["In 2019 alone, 1.54 billion smartphones were shipped worldwide.","As of 2020, 75.05% of the world's population were smartphone users.","Capacitive multi-touch screens, rather than physical keyboards, became standard after the iPhone's popularity in the late 2000s."],"where":[],"whereNote":null,"sources":[{"title":"Smartphone","url":"https://en.wikipedia.org/wiki/Smartphone"},{"title":"Touchscreen","url":"https://en.wikipedia.org/wiki/Touchscreen"},{"title":"Active-pixel sensor","url":"https://en.wikipedia.org/wiki/Active-pixel_sensor"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"smartphone-glass","name":"Smartphone cover glass","kind":"product","category":"minerals","title":"How smartphone cover glass is made","url":"https://assemblyline.org/make/smartphone-glass","stations":5,"upstream":20,"downstream":1,"depth":5,"dek":"Phone glass gets its toughness from a hot salt bath that crams bigger potassium ions into the surface.","answer":"Smartphone cover glass is a thin sheet of alkali-aluminosilicate glass, cut to size and then soaked in a molten potassium salt at about 400 °C. Larger potassium ions replace smaller sodium ions near the surface and press the outer layer into compression, which makes it resist cracks and scratches.","aka":["Gorilla Glass","phone screen glass","cover glass","chemically strengthened glass"],"inputs":["silica-sand","alumina","soda-ash","potash"],"uses":["smartphone"],"grounds":["silica-sand","potash","bauxite","water","rock-salt","limestone","trona","natural-gas","air","corn","sugarcane","sugar-beet"],"upstreamSlugs":["silica-sand","alumina","soda-ash","potash","bauxite","caustic-soda","lime","water","rock-salt","ammonia","limestone","carbon-dioxide","trona","natural-gas","air","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["smartphone"],"steps":[{"name":"Melt aluminosilicate glass","process":"melt","text":"The batch is built on silica and alumina with sodium added, so the glass has small sodium ions available for later swapping. Corning also found that adding aluminum and zirconium oxides improved the glass.","inputs":["silica-sand","alumina","soda-ash"]},{"name":"Draw it into thin sheet","process":"draw","text":"The molten glass is formed into a thin, even sheet. Corning uses the overflow downdraw method rather than floating the sheet on a tin bath.","inputs":[]},{"name":"Cut the sheet to size","process":"cut","text":"Panels are cut and ground to the shape of each screen. All cutting and grinding happens before the strengthening step, because a strengthened surface can fracture if it is cut afterward.","inputs":[]},{"name":"Soak in hot potassium salt","process":"react","text":"The glass is immersed in a bath of molten potassium salt at about 400 °C. Smaller sodium ions in the glass trade places with larger potassium ions from the bath. The extra bulk jams the surface into compression and keeps small flaws from spreading.","inputs":["potash"],"spec":"about 400 °C"},{"name":"Check hardness and flaws","process":"inspect","text":"Finished glass is tested for scratch resistance. Corning rates its glass at 622 to 701 on the Vickers hardness test.","inputs":[]}],"facts":["Corning's chemically strengthened \"muscled glass\" of the 1960s went into about 100 Dodge Dart and Plymouth Barracuda racing cars in 1968 to save weight.","As of October 2017, Gorilla Glass was used in approximately five billion devices.","Replacing small sodium ions with larger potassium ones to toughen glass surfaces was first developed by Steven Kistler in 1962."],"where":[],"whereNote":null,"sources":[{"title":"Gorilla Glass","url":"https://en.wikipedia.org/wiki/Gorilla_Glass"},{"title":"Float glass","url":"https://en.wikipedia.org/wiki/Float_glass"},{"title":"Tempered glass","url":"https://en.wikipedia.org/wiki/Tempered_glass"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"smartwatch","name":"Smartwatch","kind":"product","category":"electronics","title":"How smartwatches are made","url":"https://assemblyline.org/make/smartwatch","stations":9,"upstream":108,"downstream":0,"depth":10,"dek":"Chips land within 0.025 mm on a board that bends, and the finished stack must survive a dunking in a pressure tank.","answer":"Most of the work goes into fitting a rigid-flex circuit board around a battery inside a case with walls under 1 mm. Machines print solder paste, place the chips and reflow them. CNC mills cut metal cases, a display is vacuum-bonded under glass in a cleanroom, gaskets and adhesive seal everything, and samples get soaked, baked and dropped.","aka":["fitness watch","wearable","activity tracker"],"inputs":["printed-circuit-board","solder","microchip","memory-chip","aluminum","stainless-steel","polycarbonate","oled-screen","lcd-screen","glass","adhesive","lithium-ion-cell"],"uses":[],"grounds":["crude-oil","coal","silica-sand","limestone","water","copper-ore","air","tin-ore","lead-ore","silver-ore","zinc-ore","quartz","gold-ore","bauxite","chromite","nickel-ore","rock-salt","iron-ore","sulfur","trona","lithium-brine","spodumene","cobalt-ore","manganese-ore","natural-gas","titanium-ore","corn","dolomite","timber","sugarcane","sugar-beet"],"upstreamSlugs":["printed-circuit-board","solder","microchip","memory-chip","aluminum","stainless-steel","polycarbonate","oled-screen","lcd-screen","glass","adhesive","lithium-ion-cell","copper","fiberglass","epoxy","photoresist","tin","lead","silver","silicon-wafer","oxygen","gold","nitrogen","crude-oil","coal","petroleum-coke","alumina","steel-scrap","chromium","nickel","argon","phenol","propylene","acetone","caustic-soda","chlorine","indium-tin-oxide","pigment","led","acrylic","silica-sand","soda-ash","limestone","polyethylene","polyurethane","paraffin-wax","water","lithium-carbonate","cobalt","manganese","synthetic-graphite","steel","copper-ore","air","sulfuric-acid","phenolic-resin","tin-ore","coke","lead-ore","zinc","silver-ore","zinc-ore","lime","polysilicon","quartz","gold-ore","bauxite","propane","chromite","nickel-ore","benzene","naphtha","rock-salt","indium","iron-ore","titanium-dioxide","carbon-black","sulfur","gallium","ammonia","hydrogen","plastic","methanol","carbon-dioxide","trona","ethylene","nitric-acid","lithium-brine","spodumene","cobalt-ore","manganese-ore","natural-gas","pig-iron","magnesium","formaldehyde","silicon","hydrochloric-acid","trichlorosilane","toluene","titanium-ore","corn","yeast","dolomite","charcoal","timber","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Lay out the flexible board","process":"etch","inputs":["printed-circuit-board"],"text":"A stiff zone holds the processor, memory and power chips. Thin polyimide tails bend around the battery to reach the display on one side and the rear sensors on the other.","spec":"0.1 to 0.3 mm thick in the flex zones"},{"name":"Print the solder paste","process":"print","inputs":["solder"],"text":"A laser-cut stainless stencil lays a dab of paste on every pad. Too much or too little on a fine-pitch pad means a bridge or a cold joint that fails later under heat."},{"name":"Place and reflow chips","process":"assemble","inputs":["microchip","memory-chip"],"text":"Machines set each part on the paste, then an oven melts the lead-free alloy, with a slow ramp so copper does not peel off the polyimide. Cameras then hunt for bridges and skewed parts. Motion sensors go on here like any other chip.","spec":"245 to 260 °C peak"},{"name":"Mill the case","process":"machine","inputs":["aluminum","stainless-steel","polycarbonate"],"text":"Five-axis CNC mills cut metal cases, including the battery pocket and the crown bore, in one clamping so every feature lines up. Aluminum is then bead blasted and hard anodized. Budget models are injection molded from plastic instead."},{"name":"Bond display under glass","process":"laminate","inputs":["oled-screen","lcd-screen","glass","adhesive"],"text":"Inside a cleanroom of ISO Class 7 or cleaner, clear adhesive joins the display to the cover glass under vacuum, so no air pocket can scatter light. Ultraviolet light then cures the bond."},{"name":"Connect the battery","process":"assemble","inputs":["lithium-ion-cell"],"text":"A custom-shaped lithium polymer cell fills the odd cavity left in the case. It joins the board through a small connector, which is easier to service, or a solder joint, which has less resistance."},{"name":"Seal against water","process":"assemble","inputs":["adhesive"],"text":"Gaskets ring the display, the rear crystal and the crown, and adhesive fixes the back to the body. One patent then pumps gas through a small hole to watch for pressure loss, and plugs the hole with waterproof paste if the cavity holds."},{"name":"Probe and power up","process":"inspect","inputs":[],"text":"Spring-loaded probes touch hundreds of test points on the board before it goes in the case. Finished units are switched on to check the display, radios, GPS lock and charging, and the heart-rate sensors are calibrated."},{"name":"Bake, soak and drop","process":"inspect","inputs":[],"text":"Samples run nonstop while warm to shake out weak solder joints, then go into a pressurized tank at their rated depth and take drop tests. Every unit gets a final look for scratches and crown alignment.","spec":"24 to 48 hours at 45 to 55 °C"}],"facts":["Smartwatches charge through spring-loaded pogo pins because an open USB port would struggle to hold a water seal over thousands of connections.","The crown is the hardest seal on a smartwatch, since it must turn freely while keeping water out under pressure.","Hamilton's Pulsar, the first digital watch, dates from 1972."],"where":[],"whereNote":null,"sources":[{"title":"Smartwatch Manufacturing Process: A Step-by-Step Technical Guide","url":"https://promaxpogopin.com/how-to-guides/smartwatch-manufacturing-process/"},{"title":"US9615791B2: Wearable device and method for manufacturing the same","url":"https://patents.google.com/patent/US9615791B2/en"},{"title":"Smartwatch","url":"https://en.wikipedia.org/wiki/Smartwatch"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"smoke-detector","name":"Smoke detector","kind":"product","category":"electronics","title":"How smoke detectors are made","url":"https://assemblyline.org/make/smoke-detector","stations":8,"upstream":80,"downstream":0,"depth":10,"dek":"The first home smoke detector, sold in 1971, cost about $125.","answer":"An ionization alarm is a circuit board carrying two small chambers, each holding a speck of americium sealed in gold and silver foil. A specialist supplier may make those chambers. On the line, parts and horn go on the board, a wave of molten solder fixes them, and the board is seated in a molded plastic base. Photoelectric alarms use a light beam instead.","aka":["smoke alarm","fire alarm"],"inputs":["gold","silver","printed-circuit-board","solder","plastic","polystyrene","pvc","cardboard-box"],"uses":[],"grounds":["gold-ore","water","silver-ore","lead-ore","zinc-ore","copper-ore","natural-gas","limestone","air","rock-salt","sulfur","silica-sand","tin-ore","crude-oil","iron-ore","trona","coal","titanium-ore","timber","soybeans","rapeseed","clay","corn","sugarcane","sugar-beet"],"upstreamSlugs":["gold","silver","printed-circuit-board","solder","plastic","polystyrene","pvc","cardboard-box","gold-ore","water","lime","zinc","chlorine","silver-ore","lead-ore","zinc-ore","copper-ore","sulfuric-acid","copper","fiberglass","epoxy","photoresist","tin","lead","naphtha","natural-gas","ethylene","propylene","benzene","styrene","pigment","plasticizer","cardboard","ink","adhesive","limestone","air","rock-salt","sulfur","oxygen","silica-sand","soda-ash","phenol","acetone","caustic-soda","phenolic-resin","tin-ore","coke","crude-oil","hydrogen","toluene","iron-ore","titanium-dioxide","carbon-black","wood-pulp","vegetable-oil","ethanol","polyethylene","acrylic","polyurethane","paraffin-wax","ammonia","carbon-dioxide","trona","formaldehyde","coal","titanium-ore","timber","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","corn","sugarcane","yeast","methanol","nitric-acid","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Roll the source foil","process":"roll","inputs":["gold","silver"],"text":"At a specialist maker, americium oxide is blended with gold and fused into a briquette, then sealed under gold with a silver backing. Repeated cold rolling turns it into a thin foil strip."},{"name":"Punch and seal discs","process":"stamp","inputs":[],"text":"Tiny round discs are punched from the strip and each goes in a metal holder. A thin rim on the holder is then folded over to close off the cut edge all the way around."},{"name":"Build the two chambers","process":"assemble","inputs":[],"text":"One disc goes in the sensing chamber and one in a reference chamber next door that smoke cannot enter. Electrodes are fitted to both, with leads poking out the bottom. Many alarm makers buy these ready-made."},{"name":"Stuff the circuit board","process":"assemble","inputs":["printed-circuit-board"],"text":"Diodes, capacitors and resistors go onto the board, through punched holes with trimmed leads on older designs and by surface mounting on many current ones. The two chambers and the alarm horn are added."},{"name":"Wave-solder the board","process":"assemble","inputs":["solder"],"text":"The loaded board passes over a wave solder machine, which fixes every component in one pass."},{"name":"Mold base and cover","process":"mold","inputs":["plastic","polystyrene","pvc"],"text":"Powdered plastic and pigment are heated, pushed under pressure into a mold and cooled, giving a mounting base and a cover."},{"name":"Close the housing","process":"assemble","inputs":[],"text":"The board is seated on the base and a test button is fitted so owners can check the alarm at home. A mounting bracket and then the cover finish it, with inspections along the way."},{"name":"Box with battery","process":"package","inputs":["cardboard-box"],"text":"The alarm is boxed in cardboard along with a battery and printed instructions."}],"facts":["Ionization smoke detectors have been on sale in the United States since 1951, at first only for factories, warehouses and public buildings.","The first single-station alarm dates from 1970, ran on one 9-volt battery and cost about $125.","The photoelectric smoke detector was patented in 1972, and the 10-year lithium battery alarm arrived in 1995."],"where":[],"whereNote":null,"sources":[{"title":"Smoke Detector (How Products Are Made)","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/smoke-detector"},{"title":"Smoke detector","url":"https://en.wikipedia.org/wiki/Smoke_detector"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sneaker","name":"Sneaker","kind":"product","category":"textiles","title":"How sneakers are made","url":"https://assemblyline.org/make/sneaker","stations":6,"upstream":49,"downstream":0,"depth":8,"dek":"The word sneaker was coined for how quietly the rubber sole let you walk, and nine in ten shoes are made in Asia.","answer":"A sneaker is a fabric upper stitched together, pulled over a foot-shaped last, and glued to a rubber sole. Panels of canvas or synthetic textile are cut, sewn and fitted with eyelets. A foam midsole absorbs impact, and a tough rubber outsole grips the ground. The shoe is laced and packed.","aka":["trainers","running shoes","athletic shoes","plimsolls"],"inputs":["cotton-fabric","polyester","thread","polyurethane","rubber","adhesive"],"uses":[],"grounds":["water","natural-latex","sulfur","raw-cotton","corn","crude-oil","air","rock-salt","natural-gas","limestone","coal","sugarcane","sugar-beet"],"upstreamSlugs":["cotton-fabric","polyester","thread","polyurethane","rubber","adhesive","cotton-yarn","corn-starch","water","pet-plastic","propylene","nitric-acid","chlorine","natural-latex","synthetic-rubber","carbon-black","sulfur","polyethylene","acrylic","epoxy","paraffin-wax","raw-cotton","corn","p-xylene","ethylene","ethylene-glycol","naphtha","crude-oil","ammonia","air","rock-salt","sulfuric-acid","benzene","styrene","methanol","phenol","acetone","caustic-soda","hydrogen","natural-gas","oxygen","carbon-dioxide","toluene","yeast","limestone","coal","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the upper panels","process":"cut","text":"Dies cut the front, sides, tongue and heel pieces from rolls of fabric or synthetic textile. Layers can be stacked and cut together.","inputs":["cotton-fabric","polyester"]},{"name":"Stitch the upper","process":"sew","text":"Sewers join the pieces into a soft sock-like shape and add the tongue, eyelets and a lining. The finished upper is flat until it is molded to a foot shape.","inputs":["thread"]},{"name":"Mold the cushion layer","process":"mold","text":"A midsole sits between the outsole and the foot to absorb shock. Running shoes put extra material under the heel, where most pressure lands.","inputs":["polyurethane"]},{"name":"Press the rubber outsole","process":"mold","text":"A rubber compound is pressed into a mold with a tread pattern. Most modern soles are natural rubber, polyurethane or PVC.","inputs":["rubber"]},{"name":"Last and glue it up","process":"assemble","text":"The upper is stretched over a foot-shaped last, and its bottom edge is wrapped under. Workers coat it and the sole with cement and press them together until they bond.","inputs":["adhesive"]},{"name":"Lace and pack","process":"package","text":"Laces are threaded, the shoe is inspected and the pair goes into a box.","inputs":[]}],"facts":["In 1892, the U.S. Rubber Company introduced the first rubber-soled shoes in the United States.","The word sneaker is often attributed to Henry Nelson McKinney, an advertising agent who used it in 1917 because the rubber sole made the wearer's steps stealthy.","Adolf Dassler began making sports shoes in his mother's wash kitchen in Herzogenaurach, and went on to found Adidas."],"where":[],"whereNote":null,"sources":[{"title":"Sneakers","url":"https://en.wikipedia.org/wiki/Sneakers"},{"title":"Shoe","url":"https://en.wikipedia.org/wiki/Shoe"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"snow-globe","name":"Snow globe","kind":"product","category":"play","title":"How snow globes are made","url":"https://assemblyline.org/make/snow-globe","stations":9,"upstream":81,"downstream":0,"depth":10,"dek":"Snow globes are often sealed underwater, with the figure plugged in while the dome sits submerged in a tank.","answer":"A snow globe is filled and closed underwater. In the usual method described by one patent, an empty dome is turned upside down over a tank of liquid, flakes go in, and it sinks and fills. A plug carrying the figure is pushed home while still submerged, so no air gets trapped. Figures are cast, painted and waterproofed first.","aka":["snowglobe","water globe","snow dome"],"inputs":["glass","plastic","porcelain","paint","adhesive","water","glycerin"],"uses":[],"grounds":["water","silica-sand","limestone","natural-gas","kaolin","quartz","feldspar","rock-salt","trona","crude-oil","iron-ore","sulfur","titanium-ore","oil-palm-fruit","soybeans","rapeseed","clay","air","corn","coal","tin-ore","sugarcane","sugar-beet","dolomite","manganese-ore","timber"],"upstreamSlugs":["glass","plastic","porcelain","paint","adhesive","water","glycerin","silica-sand","soda-ash","limestone","naphtha","natural-gas","ethylene","propylene","kaolin","quartz","feldspar","pigment","titanium-dioxide","acrylic","tin-can","polyethylene","epoxy","polyurethane","paraffin-wax","palm-oil","vegetable-oil","caustic-soda","methanol","rock-salt","ammonia","carbon-dioxide","lime","trona","crude-oil","hydrogen","iron-ore","carbon-black","sulfur","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","tinplate","lacquer","ink","phenol","acetone","nitric-acid","oil-palm-fruit","soybeans","rapeseed","hexane","clay","air","corn","yeast","coal","steel","tin","ethanol","phenolic-resin","benzene","molasses","pig-iron","magnesium","steel-scrap","manganese","argon","tin-ore","sugarcane","formaldehyde","toluene","sugar-beet","dolomite","silicon","propane","manganese-ore","charcoal","timber"],"downstreamSlugs":[],"steps":[{"name":"Make the dome","process":"blow","text":"Snow globes were traditionally glass, with heavy lead glass domes in the early days. Plastic became available in the 1950s, and modern domes are made in either.","inputs":["glass"]},{"name":"Cast the figure","process":"cast","text":"A clay master, once approved, is used to make a mold for polyresin figures and bases. Polyresin is also a common choice for the base of promotional globes, and older makers often used porcelain or ceramic.","inputs":["plastic","porcelain"]},{"name":"Set and grind","process":"grind","text":"One Chinese factory sets the casting in a vacuum chamber and soaks it in alkaline water. Workers then trim and grind figure and base to smooth away the seams.","inputs":[]},{"name":"Paint and waterproof","process":"coat","text":"Once painted, the figure is sprayed with a waterproof oil so the color cannot wear off in the liquid. It dries, and the underside of the base is smoothed again so the globe will sit level.","inputs":["paint"]},{"name":"Fit the gasket","process":"assemble","text":"A plastic gasket goes on under the figure, which is cleaned and returned to the vacuum chamber one last time.","inputs":["plastic","adhesive"]},{"name":"Sink and fill","process":"fill","text":"The dome is held upside down over a large tank and the flakes go in. It then sinks and fills with liquid, often a blend with glycerin so the snow falls slowly. The mix can be adjusted for the climate where a globe is headed.","inputs":["water","glycerin","plastic"]},{"name":"Plug it underwater","process":"assemble","text":"Still submerged, the plug carrying the figure is pressed into the opening so no bubbles are caught. A convex plug wall locks into a concave skirt for a watertight seal. One patent adds a flexible diaphragm so that the plug can move as the liquid expands.","inputs":[]},{"name":"Stand it upright","process":"assemble","text":"Filled globes come out of the tank and turn right side up, resting on the skirt or set into a decorative base. Any globe with bubbles gets caught at this point.","inputs":[]},{"name":"Wrap in foam","process":"package","text":"Each globe is wrapped in styrofoam and placed in its box for shipping.","inputs":[]}],"facts":["Water-filled paperweights holding a man with an umbrella were already on show at the 1878 Paris Exposition.","The Vienna family company makes about 200,000 snow globes a year."],"where":[],"whereNote":null,"sources":[{"title":"US6540099B2, Sealing plug for a water globe","url":"https://patents.google.com/patent/US6540099B2/en"},{"title":"China Manufacturing: How Custom Snow Globes Are Made, The ODM Group","url":"https://www.theodmgroup.com/china-manufacturing-custom-snow-globes"},{"title":"Snow globe","url":"https://en.wikipedia.org/wiki/Snow_globe"},{"title":"Let it snow, Discover Germany","url":"https://www.discovergermany.com/let-it-snow/"},{"title":"Christmas in a globe, Euronews","url":"https://www.euronews.com/2023/12/05/christmas-in-a-globe-made-in-vienna-snow-globes-still-going-strong-after-100-years"},{"title":"How are snow globes made?, The Music Box Attic","url":"https://www.musicboxattic.com/blog/how-are-snow-globes-made-a-behind-the-scenes-look-at-the-magic"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"snowboard","name":"Snowboard","kind":"product","category":"play","title":"How snowboards are made","url":"https://assemblyline.org/make/snowboard","stations":10,"upstream":74,"downstream":0,"depth":8,"dek":"A snowboard is stacked like a sandwich, base first and topsheet last, then squeezed in a heated press for about 15 minutes.","answer":"Layers go into an aluminum form from the bottom up: a plastic base with steel edges, epoxy, fiberglass, a tapered wood core, more fiberglass and a printed topsheet. A heated press cures the resin and squeezes out the excess. The raw slab is then trimmed, its base and edges are ground on belts, and the board gets a hot wax.","aka":["snow board","snowboards"],"inputs":["lumber","adhesive","polyethylene","ink","steel","epoxy","rubber","fiberglass","abs-plastic"],"uses":[],"grounds":["timber","water","natural-latex","sulfur","silica-sand","limestone","air","crude-oil","natural-gas","soybeans","rapeseed","clay","titanium-ore","iron-ore","corn","sugarcane","dolomite","manganese-ore","rock-salt","trona","coal","quartz","sugar-beet"],"upstreamSlugs":["lumber","adhesive","polyethylene","ink","steel","epoxy","rubber","fiberglass","abs-plastic","timber","acrylic","polyurethane","paraffin-wax","water","ethylene","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","phenol","propylene","acetone","chlorine","caustic-soda","natural-latex","synthetic-rubber","sulfur","silica-sand","limestone","soda-ash","naphtha","ammonia","air","benzene","styrene","sulfuric-acid","methanol","nitric-acid","crude-oil","hydrogen","natural-gas","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","coke","iron-ore","corn","sugarcane","yeast","dolomite","silicon","propane","manganese-ore","rock-salt","carbon-dioxide","trona","toluene","coal","molasses","quartz","charcoal","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Laminate a core block","process":"laminate","text":"Strips of wood are glued into a block that holds six to eight cores. Never Summer blends fast-growing paulownia with poplar, and puts beech in the high-stress zones.","inputs":["lumber","adhesive"]},{"name":"Saw the sidecut, slice the block","process":"cut","text":"A band saw and a router cut the curved outline into the block. Most boards use a radius of 8 to 9 meters, which steers them through a turn. Plastic sidewalls are glued on and cure for 24 hours, and then the block is sliced into individual cores.","inputs":["polyethylene","adhesive"],"spec":"24-hour sidewall cure"},{"name":"Taper and drill each core","process":"grind","text":"Mounting holes are drilled, and a programmable wide sander thins the core toward the nose and tail. Thickness is set to the millimeter, because it decides how the board flexes.","inputs":[]},{"name":"Print base and topsheet","process":"print","text":"Burton silkscreens its graphics with water-based inks, one screen per color. Never Summer prints topsheet art on clay-based paper and uses a hot press to sublimate it into the plastic, so it cannot scrape off.","inputs":["ink"]},{"name":"Bend edges around the base","process":"assemble","text":"The polyethylene base is cut to shape. Steel edge arrives as a long roll, is rough-shaped by machine, and is then bent around the base with crimping pliers and glued on.","inputs":["polyethylene","steel","adhesive"]},{"name":"Lay up in an aluminum form","process":"laminate","text":"The base goes into a machined aluminum form made for that model and size. On top go epoxy, rubber strips, fiberglass, more epoxy, the wood core, more fiberglass and resin, and the topsheet. An experienced builder can do this in 10 minutes.","inputs":["epoxy","rubber","fiberglass","abs-plastic"]},{"name":"Cure in a heated press","process":"press","text":"Heat activates the epoxy and pressure squeezes the excess out. Burton's prototype shop cures boards for 10 to 15 minutes at about 70 pounds per square inch, and Never Summer for roughly 19 minutes. The mold also sets the camber or rocker and the upturned nose and tail.","inputs":[],"spec":"about 70 psi for 10 to 15 minutes"},{"name":"Trim the overhang","process":"cut","text":"The board leaves the form as a square-edged slab. A technician follows the steel edge with a band saw to cut away the extra material, and the sidewall is then ground to its final shape.","inputs":[]},{"name":"Grind base and edges","process":"grind","text":"Sanding belts of decreasing coarseness flatten the base and remove hardened resin. At Burton a board can take as many as sixteen passes. The edges then get a one-degree bevel.","inputs":[]},{"name":"Wax and inspect","process":"inspect","text":"A hot wax goes on the base. Never Summer's inspectors run a 20-point check before a board ships.","inputs":[]}],"facts":["The direct ancestor of the snowboard was the 1965 Snurfer, which had no bindings. Riders held a looped nylon cord.","Burton's first boards in the 1970s were single pieces of wood.","Two colors of base plastic can be die-cut with the same logo and their pieces swapped like a puzzle, so one sheet gives both a graphic and a background."],"where":[],"whereNote":null,"sources":[{"title":"How is a snowboard made?","url":"https://www.burton.com/blogs/the-burton-blog/how-is-a-snowboard-made"},{"title":"How Never Summer Snowboards Are Made","url":"https://neversummer.com/blogs/snowboarding/how-never-summer-snowboards-are-made-inside-our-colorado-factory"},{"title":"Snowboard","url":"https://en.wikipedia.org/wiki/Snowboard"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"soap","name":"Soap","kind":"product","category":"body-health","title":"How soap is made","url":"https://assemblyline.org/make/soap","stations":8,"upstream":60,"downstream":0,"depth":10,"dek":"Soap is a chemical reaction between fat and lye, and the leftover glycerin is worth keeping.","answer":"Soap forms when vegetable or animal fat meets a strong alkali such as lye. The reaction splits each fat molecule into soap and glycerin. Makers then wash out the extra alkali, dry the soap, press it into a uniform mass and stamp it into bars. Some of the glycerin is separated and sold on, and some stays in the bar to soften it.","aka":["bar soap","toilet soap","saponification"],"inputs":["palm-oil","vegetable-oil","caustic-soda","water","rock-salt","glycerin","paper","cardboard-box"],"uses":[],"grounds":["water","rock-salt","oil-palm-fruit","soybeans","rapeseed","clay","kaolin","limestone","crude-oil","natural-gas","timber","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","coal","sugar-beet"],"upstreamSlugs":["palm-oil","vegetable-oil","caustic-soda","water","rock-salt","glycerin","paper","cardboard-box","oil-palm-fruit","soybeans","rapeseed","hexane","clay","methanol","wood-pulp","kaolin","limestone","cardboard","ink","adhesive","crude-oil","hydrogen","natural-gas","timber","lime","oxygen","hydrogen-peroxide","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","air","phenol","formaldehyde","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","ethylene","propylene","ammonia","acetone","nitric-acid","benzene","coal","molasses","naphtha","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Blend the fats","process":"mix","text":"Palm oil, coconut oil and other fats are blended in a tank, because each fat gives the bar a different hardness and lather. The blend is cleaned and warmed until it flows like thin syrup.","inputs":["palm-oil","vegetable-oil"]},{"name":"Cook with lye","process":"react","text":"The warm fat meets a solution of caustic soda in a large vessel. This reaction, called saponification, breaks each fat molecule into fatty acid salts and glycerin. The salts are the soap.","inputs":["caustic-soda","water"]},{"name":"Salt out the soap","process":"separate","text":"Adding brine makes the soap curds float on top while water, glycerin and leftover lye settle underneath. The heavy layer is drained off, and the curds can be rinsed and salted again.","inputs":["rock-salt"]},{"name":"Recover the glycerin","process":"refine","text":"The drained liquid is a dilute glycerin solution. Plants evaporate and purify it, and it goes on to creams, medicines and food. Some glycerin is left in the soap to make it softer.","inputs":["glycerin"]},{"name":"Dry the curds","process":"dry","text":"Hot air removes water from the soap until it is a firm, crumbly mass of flakes or chips. Too wet and the bar goes mushy, and too dry and it cracks.","inputs":[]},{"name":"Mill and press","process":"extrude","text":"The chips are blended with perfume and color, rolled between stone or steel rollers, and squeezed through a nozzle as a continuous bar. Repeated milling makes the soap smooth and dense.","inputs":[]},{"name":"Stamp into bars","process":"stamp","text":"The long bar is cut into billets, and a die presses the brand and shape into each one in a single stroke.","inputs":[]},{"name":"Wrap and box","process":"package","text":"Machines fold paper or film around each bar and drop it into cartons.","inputs":["paper","cardboard-box"]}],"facts":["People were making soap-like materials in ancient Babylon around 2800 BC.","Glycerin soap is ordinary soap with extra glycerin added to it."],"where":[],"whereNote":null,"sources":[{"title":"Soap","url":"https://en.wikipedia.org/wiki/Soap"},{"title":"Laundry detergent","url":"https://en.wikipedia.org/wiki/Laundry_detergent"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"soccer-ball","name":"Soccer ball","kind":"product","category":"play","title":"How soccer balls are made","url":"https://assemblyline.org/make/soccer-ball","stations":7,"upstream":52,"downstream":0,"depth":8,"dek":"The classic ball is a truncated icosahedron: 12 pentagons and 20 hexagons, stitched round an inflated bladder.","answer":"A soccer ball is a rubber or plastic bladder inside a stitched or glued shell of 32 panels. Synthetic leather is laminated, cut into pentagons and hexagons, and printed. The panels are joined around the bladder, which is then inflated to between 0.6 and 1.1 atmospheres and checked for weight, size and roundness.","aka":["football","association football ball"],"inputs":["polyurethane","polyester","ink","rubber","thread","air"],"uses":[],"grounds":["air","water","natural-latex","sulfur","crude-oil","rock-salt","soybeans","rapeseed","clay","titanium-ore","iron-ore","corn","sugarcane","natural-gas","coal","limestone","sugar-beet"],"upstreamSlugs":["polyurethane","polyester","ink","rubber","thread","air","propylene","nitric-acid","chlorine","water","pet-plastic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","natural-latex","synthetic-rubber","sulfur","naphtha","crude-oil","ammonia","rock-salt","sulfuric-acid","p-xylene","ethylene","ethylene-glycol","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","titanium-ore","coke","oxygen","iron-ore","corn","sugarcane","yeast","benzene","styrene","hydrogen","natural-gas","carbon-dioxide","methanol","coal","molasses","toluene","limestone","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Laminate the panel material","process":"laminate","text":"Layers of fabric and foam are glued under a skin of synthetic leather. The stack is waterproof, springy and tough.","inputs":["polyurethane","polyester"]},{"name":"Print the colors","process":"print","text":"Designs are printed onto the sheet before it is cut, so the graphics line up across the panels.","inputs":["ink"]},{"name":"Punch out the panels","process":"cut","text":"Dies cut 12 pentagons and 20 hexagons. The two shapes are often different colors, which makes the ball easy to follow on TV.","inputs":[]},{"name":"Make the bladder","process":"mold","text":"A rubber or plastic bladder is made with a valve. It holds the air that makes the ball bounce.","inputs":["rubber"]},{"name":"Stitch the panels","process":"sew","text":"Panels are sewn together by hand or machine, leaving one seam open. Some balls are thermally bonded instead.","inputs":["thread"]},{"name":"Insert the bladder","process":"assemble","text":"The bladder goes in through the open seam, which is then closed. The cover bulges into a near-perfect sphere when it is inflated.","inputs":[]},{"name":"Inflate and check","process":"inspect","text":"Balls are pumped up and checked for size, weight and roundness. Under the laws of the game, a ball weighs 410 to 450 grams.","inputs":["air"]}],"facts":["The oldest football still in existence, from around 1550, was found in the roof of Stirling Castle in 1981.","The first 32-panel ball was marketed by the company Select in Denmark in the 1950s."],"where":[],"whereNote":null,"sources":[{"title":"Football (ball)","url":"https://en.wikipedia.org/wiki/Football_(ball)"},{"title":"Basketball (ball)","url":"https://en.wikipedia.org/wiki/Basketball_(ball)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"socks","name":"Socks","kind":"product","category":"textiles","title":"How socks are made","url":"https://assemblyline.org/make/socks","stations":6,"upstream":30,"downstream":0,"depth":8,"dek":"A town in Zhejiang, China, makes 8 billion pairs of socks a year, a third of the world's supply.","answer":"A circular knitting machine turns yarn into a continuous tube in 20 to 40 seconds, with hundreds of needles working around a rotating cylinder. The open toe is seamed or linked shut, and the socks are washed, then pulled over heated metal foot forms for boarding. Each is inspected, then matched into pairs and packed.","aka":["hosiery","stockings","ankle socks"],"inputs":["cotton-yarn","wool-yarn","nylon","thread","water"],"uses":[],"grounds":["water","raw-cotton","fleece","air","natural-gas","crude-oil","coal","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["cotton-yarn","wool-yarn","nylon","thread","water","raw-cotton","fleece","benzene","nitric-acid","ammonia","polyester","naphtha","hydrogen","toluene","air","natural-gas","pet-plastic","crude-oil","coal","p-xylene","ethylene","ethylene-glycol","oxygen","carbon-dioxide","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Prepare the yarn","process":"spin","text":"Fibers are spun and plied into yarn, and colored either before spinning or as spun yarn. Multi-color patterns need each yarn dyed ahead of knitting. Blends of cotton, wool and nylon are combined during spinning or plying.","inputs":["cotton-yarn","wool-yarn","nylon"]},{"name":"Knit the tube","process":"weave","text":"A rotating cylinder of needles grabs yarn and forms interlocking loops, one course per turn, knitting from cuff to toe. Needle count sets the fineness, with 84 to 108 needles for athletic socks and up to 200 for sheer ones.","inputs":[],"spec":"20 to 40 seconds"},{"name":"Close the toe","process":"sew","text":"The tube comes off open-ended, and a seaming or linking machine shuts the toe. Linking takes more labor, and some newer knitting machines close the toe in the same cycle.","inputs":["thread"]},{"name":"Wash the batch","process":"wash","text":"Knitted socks are washed before they are shaped. Simple uniform colors can be piece dyed here.","inputs":["water"]},{"name":"Board on foot forms","process":"heat-treat","text":"A baggy sock is pulled over a flat metal form shaped like a foot and passed through a setting machine with steam under pressure. It comes out holding that shape.","inputs":[]},{"name":"Inspect, pair and pack","process":"package","text":"Each sock is examined for defects, matched with its partner and packed for shipping. The whole job takes two to four hours of active production.","inputs":[]}],"facts":["Machine-knit socks were first produced in the late 16th century, and William Lee invented the stocking frame in 1589.","Toe socks have a separate compartment for each toe, like fingers in a glove."],"where":[{"place":"Zhuji, China","share":"about a third of world sock production"}],"whereNote":"Datang township, quoted by Wikipedia with no year.","sources":[{"title":"DeadSoxy: How socks are made, inside the manufacturing process","url":"https://deadsoxy.com/blogs/private-label-socks-manufacturing/how-socks-are-made-inside-the-manufacturing-process"},{"title":"iCompression Socks: How custom socks are made","url":"https://www.icompressionsocks.com/?p=18658"},{"title":"Sock","url":"https://en.wikipedia.org/wiki/Sock"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"soda","name":"Soda","kind":"product","category":"drink","title":"How soda is made","url":"https://assemblyline.org/make/soda","stations":5,"upstream":76,"downstream":0,"depth":9,"dek":"Soda is about one part flavored syrup to five parts water that has been pumped full of carbon dioxide.","answer":"Soda is made by dissolving carbon dioxide into cold water under pressure, then mixing it with a flavored syrup at about five parts water to one part syrup. The syrup carries sweetener, acid, color and flavor oils. The fizzy drink is sealed into bottles or cans before the gas can escape.","aka":["pop","soft drink","fizzy drink","cola"],"inputs":["sugar","corn-syrup","phosphoric-acid","caramel-color","water","carbon-dioxide","aluminum-can","plastic-bottle","glass-bottle","cardboard"],"uses":[],"grounds":["water","sugarcane","sugar-beet","corn","phosphate-rock","silica-sand","natural-gas","limestone","sulfur","air","coal","barley","crude-oil","rock-salt","trona","timber","bauxite","soybeans","rapeseed","clay","titanium-ore","iron-ore"],"upstreamSlugs":["sugar","corn-syrup","phosphoric-acid","caramel-color","water","carbon-dioxide","aluminum-can","plastic-bottle","glass-bottle","cardboard","sugarcane","sugar-beet","lime","corn","corn-starch","phosphate-rock","sulfuric-acid","coke","silica-sand","molasses","malted-barley","ammonia","natural-gas","yeast","limestone","aluminum","ink","epoxy","pet-plastic","soda-ash","polyethylene","wood-pulp","adhesive","sulfur","air","coal","barley","crude-oil","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","phenol","propylene","acetone","chlorine","caustic-soda","p-xylene","ethylene","ethylene-glycol","rock-salt","trona","timber","oxygen","hydrogen-peroxide","acrylic","polyurethane","paraffin-wax","bauxite","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","iron-ore","benzene","naphtha","hydrogen","methanol","nitric-acid","toluene"],"downstreamSlugs":[],"steps":[{"name":"Mix the syrup","process":"mix","text":"Syrup is built from a sweetener such as sugar or high-fructose corn syrup, food coloring, an acid and flavor oils. Colas use phosphoric acid, and fruit sodas use citric acid.","inputs":["sugar","corn-syrup","phosphoric-acid","caramel-color","water"]},{"name":"Dissolve gas in water","process":"react","text":"Carbon dioxide is injected into water under high pressure. The gas is only weakly soluble, so pressure forces it in and it stays dissolved until the pressure is released. Food-grade carbon dioxide often comes from ammonia plants.","inputs":["carbon-dioxide","water"]},{"name":"Blend syrup and fizz","process":"mix","text":"Syrup and carbonated water are combined at a ratio of about one to five. Colas and ginger ale are carbonated to about 3.5 volumes of gas per volume of liquid, while fruity drinks get less.","inputs":[],"spec":"1 part syrup to 5 parts water"},{"name":"Fill and seal fast","process":"fill","text":"The drink goes into glass, plastic or aluminum containers that can take the pressure of the gas. The seal has to be tight, since a poor one lets the bubbles out and a weak bottle can burst.","inputs":["aluminum-can","plastic-bottle","glass-bottle"]},{"name":"Box and ship","process":"package","text":"Cans and bottles are grouped into cardboard cartons or trays, a packaging style that took off in the 1920s.","inputs":["cardboard"]}],"facts":["Joseph Priestley invented carbonated water in 1767 by hanging a bowl of water above a beer vat at a Leeds brewery.","Before the crown cork seal was patented in 1892, bottle makers struggled to keep the bubbles in.","J. J. Schweppe started selling bottled carbonated water in 1783."],"where":[],"whereNote":null,"sources":[{"title":"Soft drink","url":"https://en.wikipedia.org/wiki/Soft_drink"},{"title":"Carbonated water","url":"https://en.wikipedia.org/wiki/Carbonated_water"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"soda-ash","name":"Soda ash","kind":"material","category":"chemicals","title":"How soda ash is made","url":"https://assemblyline.org/make/soda-ash","stations":8,"upstream":14,"downstream":176,"depth":4,"dek":"Most soda ash starts as salt water and limestone, and the plant recycles its own ammonia over and over.","answer":"Soda ash is made by bubbling carbon dioxide from burnt limestone through salty brine that has been loaded with ammonia. Baking soda crystals drop out of the liquid and are heated to leave sodium carbonate. The ammonia is then recovered and reused. Where natural trona is mined nearby, it can simply be baked instead.","aka":["sodium carbonate","washing soda","soda crystals","Solvay process"],"inputs":["rock-salt","water","ammonia","limestone","carbon-dioxide","lime","trona"],"uses":["detergent","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","baking-soda","instant-noodles","stained-glass","vanadium"],"grounds":["rock-salt","water","limestone","trona","natural-gas","air","corn","sugarcane","sugar-beet"],"upstreamSlugs":["rock-salt","water","ammonia","limestone","carbon-dioxide","lime","trona","natural-gas","air","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["detergent","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","baking-soda","instant-noodles","stained-glass","vanadium","printed-circuit-board","wind-turbine","surfboard","ski","snowboard","fishing-rod","kite","roof-shingle","vinyl-floor","canoe","sailboat","umbrella","lithium-ion-cell","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather","thermometer","lcd-screen","oled-screen","camera-sensor","solar-panel","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","floor-tile","neon-sign","smartwatch","e-reader","mirror","skyscraper","windshield","double-glazed-window","nail-polish","perfume","penicillin","insulin","vaccine","ketchup","cola","sparkling-water","beer","wine","champagne","whiskey","vodka","gin","rum","tequila","sake","hard-cider","hot-sauce","soda","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","port-wine","prosecco","non-alcoholic-beer","smartphone","pretzel","frozen-pizza","bagel","crackers","cake-mix","fire-extinguisher","hearing-aid","pacemaker","led-bulb","ev-battery","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","washing-machine","drone","satellite","car","electric-car","airbag","airplane","rocket","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","smoke-detector","wireless-earbuds","phone-charger","digital-camera","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","syringe","electric-kettle","kitchen-knife","fork","fountain-pen","thermos","water-bottle","pressure-cooker","dishwasher","golf-club","asthma-inhaler","subway-train","jet-engine","baseball","basketball","tennis-racket","football","saxophone","winter-gloves","leather-belt","handbag","wallet","hiking-boots","high-heels","leather-shoe","eyeglass-frame","mustard","salsa","pickles","sauerkraut","jam","hazelnut-spread","aluminum-window-frame","shampoo","deodorant","air-freshener","dish-soap","hairspray","foundation-makeup","mayonnaise"],"steps":[{"name":"Dissolve salt into brine","process":"mix","text":"Salt from the ground or from evaporated seawater is dissolved in water until the liquid is saturated. This brine supplies the sodium for the whole process.","inputs":["rock-salt","water"]},{"name":"Load the brine with ammonia","process":"react","text":"Ammonia gas is absorbed into the brine. The plant buys very little of it, because almost all of it is recaptured at the end and sent back here.","inputs":["ammonia"]},{"name":"Burn limestone for gas","process":"fire","text":"Limestone is heated in a kiln, which gives off carbon dioxide gas and leaves quicklime behind. The gas feeds the next station and the lime is saved for the last one.","inputs":["limestone"]},{"name":"Bubble gas up through the brine","process":"react","text":"Solvay's absorption tower stood 24 m tall. Carbon dioxide rises through a slow downward flow of ammoniated brine, and white crystals of sodium bicarbonate form and sink.","inputs":["carbon-dioxide"]},{"name":"Filter out the crystals","process":"separate","text":"Filters pull the bicarbonate from the liquid that is left, which is rich in ammonium chloride. Crystals are washed and carried onward.","inputs":[]},{"name":"Heat the crystals to ash","process":"fire","text":"Calcining drives off water and carbon dioxide, leaving dry, white, anhydrous sodium carbonate. Released gas is captured and sent back to the tower.","inputs":[]},{"name":"Recover the ammonia","process":"refine","text":"Quicklime from the kiln is slaked with water and mixed into the ammonium chloride liquid, which frees the ammonia as a gas. Calcium chloride solution is the only real waste.","inputs":["lime","water"]},{"name":"Calcine mined trona instead","process":"fire","text":"Near natural deposits, such as the Green River beds in Wyoming, miners dig the mineral trona and heat it to get sodium carbonate directly. It skips every station above.","inputs":["trona"]}],"facts":["Soda ash is named for the ashes of salt-loving plants, which people burned for centuries to get an alkali for glass and soap.","Large trona deposits were found near the Green River in Wyoming in 1938, and they let American plants produce soda ash more cheaply than the Solvay route.","The key reaction was spotted in 1811 by the French physicist Augustin Fresnel, decades before Ernest Solvay made it work as a factory process."],"where":[],"whereNote":null,"sources":[{"title":"Solvay process","url":"https://en.wikipedia.org/wiki/Solvay_process"},{"title":"Sodium carbonate","url":"https://en.wikipedia.org/wiki/Sodium_carbonate"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sofa","name":"Sofa","kind":"product","category":"textiles","title":"How sofas are made","url":"https://assemblyline.org/make/sofa","stations":7,"upstream":63,"downstream":0,"depth":9,"dek":"Some factory sofas are vacuum-squeezed to half their size so they fit in a shipping box.","answer":"A factory sofa starts as a frame of kiln-dried wood or MDF, glued and screwed together. Zigzag springs stretch across the seat, and foam goes on top. Fabric cut in stacks is sewn into covers, which are pulled tight over the padded frame and stapled. Legs go on last, followed by inspection and packing.","aka":["couch","settee","davenport"],"inputs":["lumber","mdf","adhesive","steel-wire","polyurethane","polyester","cotton-fabric","thread"],"uses":[],"grounds":["timber","water","crude-oil","air","rock-salt","raw-cotton","corn","natural-gas","sulfur","iron-ore","limestone","dolomite","manganese-ore","coal","quartz","sugarcane","sugar-beet"],"upstreamSlugs":["lumber","mdf","adhesive","steel-wire","polyurethane","polyester","cotton-fabric","thread","timber","paraffin-wax","polyethylene","acrylic","epoxy","water","steel","propylene","nitric-acid","chlorine","pet-plastic","cotton-yarn","corn-starch","crude-oil","hydrogen","ethylene","ammonia","sulfuric-acid","methanol","phenol","acetone","caustic-soda","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","naphtha","air","rock-salt","p-xylene","ethylene-glycol","raw-cotton","corn","natural-gas","sulfur","benzene","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","carbon-dioxide","toluene","coal","quartz","charcoal","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Build the wooden frame","process":"assemble","text":"Kiln-dried wood or MDF is cut by saws and CNC machines into arms, back and seat, then joined with screws and glue. Well-made frames add reinforced joints.","inputs":["lumber","mdf","adhesive"]},{"name":"Stretch the seat springs","process":"assemble","text":"Springs go across the seat frame first and are pulled tight. Zigzag serpentine wires are common and cheap, and classic hand-tied coils are giving way to mechanically attached grids.","inputs":["steel-wire"]},{"name":"Cut and layer the foam","process":"cut","text":"Foam blocks are carved with hot wires or blades. Firm foam goes at the bottom for support, softer foam on top, and fiber or feathers can be added for softness.","inputs":["polyurethane","polyester"]},{"name":"Cut the cover fabric","process":"cut","text":"Fabric is inspected and laid out in stacks up to 20 layers deep, then cut to patterns that leave few scraps.","inputs":["cotton-fabric"]},{"name":"Sew the covers","process":"sew","text":"Machines stitch the panels into fitted covers, with heavy-duty machines for thick leather seams.","inputs":["thread"]},{"name":"Pull on the covers","process":"assemble","text":"Covers are pulled tight over the padded frame with no wrinkles, then fixed with staples or nails. Legs and any hardware go on next.","inputs":[]},{"name":"Inspect and pack","process":"inspect","text":"Inspectors check seams and sit-test the sofa. Packing adds foam corners and cardboard, and vacuum packing shrinks some sofas down to half size.","inputs":[]}],"facts":["Hand-built sofas are an older craft: burlap, flax twine and tied coil springs, with thin rosewood layers glued cross-grain for carved Victorian backs.","Fabric for sofas can be cut up to 20 layers at a time."],"where":[],"whereNote":null,"sources":[{"title":"How Are Sofas Made? The Complete Furniture Manufacturing Process Explained","url":"https://www.forestfurniture-b2b.com/news/how-are-sofas-made-the-complete-furniture-manufacturing-process-explained/"},{"title":"Sofa Manufacturing Process: All You Should Know","url":"https://doenfurniture.com/sofa-manufacturing-process-all-you-should-know/"},{"title":"Sofa","url":"https://www.encyclopedia.com/literature-and-arts/fashion-design-and-crafts/interior-design-and-home-furnishings/sofa"},{"title":"Couch","url":"https://en.wikipedia.org/wiki/Couch"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"solar-cell","name":"Solar cell","kind":"product","category":"electronics","title":"How solar cells are made","url":"https://assemblyline.org/make/solar-cell","stations":5,"upstream":34,"downstream":2,"depth":7,"dek":"Adjusted for inflation, solar modules cost $96 a watt in the mid-1970s and as little as 20 cents in 2020.","answer":"A solar cell is a thin silicon wafer with a p-n junction made by diffusing a thin n-type layer into the face of a lightly p-type wafer. A coating cuts reflected light, and metal contacts are printed on the faces. Cells made this way produce about half a volt each, and crystalline silicon makes up 95% of the market.","aka":["photovoltaic cell","PV cell","silicon solar cell"],"inputs":["silicon-wafer","silver","aluminum"],"uses":["solar-panel"],"grounds":["quartz","silver-ore","lead-ore","zinc-ore","copper-ore","crude-oil","coal","air","sulfur","water","limestone","bauxite","timber","natural-gas","rock-salt"],"upstreamSlugs":["silicon-wafer","silver","aluminum","polysilicon","quartz","argon","silver-ore","lead-ore","zinc-ore","copper-ore","zinc","sulfuric-acid","lime","crude-oil","coal","petroleum-coke","alumina","silicon","hydrochloric-acid","trichlorosilane","hydrogen","nitrogen","air","sulfur","water","limestone","bauxite","caustic-soda","coke","charcoal","timber","chlorine","natural-gas","rock-salt"],"downstreamSlugs":["solar-panel","satellite"],"steps":[{"name":"Saw thin wafers","process":"cut","text":"Ingots of silicon are sliced into wafers. Square wafers for solar are 100 to 200 mm across and 100 to 500 micrometers thick.","inputs":["silicon-wafer"]},{"name":"Diffuse the junction layer","process":"react","text":"The wafers are lightly p-type already. A hot diffusion of n-type dopants into the front face forms a p-n junction a few hundred nanometers below the surface, which pushes freed electrons in one direction when light hits.","inputs":[]},{"name":"Coat against reflection","process":"coat","text":"An anti-reflective coating goes on the front, so the cell absorbs light instead of bouncing it back.","inputs":[]},{"name":"Print the metal contacts","process":"print","text":"Fine metal lines on the sunny face collect current, and a contact layer goes on the back.","inputs":["silver","aluminum"]},{"name":"Test and sort cells","process":"inspect","text":"Each cell is flashed with light and sorted by its output, so cells wired together later are well matched.","inputs":[]}],"facts":["A single-junction silicon cell produces only about 0.5 to 0.6 volts.","Charles Fritts built a 1% efficient selenium cell in 1883."],"where":[],"whereNote":null,"sources":[{"title":"Solar cell","url":"https://en.wikipedia.org/wiki/Solar_cell"},{"title":"Wafer (electronics)","url":"https://en.wikipedia.org/wiki/Wafer_%28electronics%29"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"solar-panel","name":"Solar panel","kind":"product","category":"electronics","title":"How solar panels are made","url":"https://assemblyline.org/make/solar-panel","stations":11,"upstream":59,"downstream":1,"depth":8,"dek":"The plastic film in a solar panel goes into the laminator milky and comes out clear, glued for good to cells and glass.","answer":"Solar panels start from finished cells, sorted by output under simulated sunlight. Machines solder them into strings with copper ribbon and stack them between glass and a plastic back sheet, with film called EVA on both sides. Heat and vacuum turn the milky film clear and glue the sandwich together. An aluminum frame, a junction box and a flash test finish the job.","aka":["PV module","photovoltaic panel","solar module"],"inputs":["solar-cell","glass","plastic","copper","solder","copper-wire","aluminum","silicone"],"uses":["satellite"],"grounds":["silica-sand","limestone","natural-gas","copper-ore","water","air","crude-oil","coal","quartz","silver-ore","lead-ore","zinc-ore","rock-salt","trona","sulfur","tin-ore","bauxite","timber","corn","sugarcane","sugar-beet"],"upstreamSlugs":["solar-cell","glass","plastic","copper","solder","copper-wire","aluminum","silicone","silicon-wafer","silver","silica-sand","soda-ash","limestone","naphtha","natural-gas","ethylene","propylene","copper-ore","water","oxygen","air","sulfuric-acid","tin","lead","crude-oil","coal","petroleum-coke","alumina","silicon","methanol","hydrochloric-acid","polysilicon","quartz","argon","silver-ore","lead-ore","zinc-ore","zinc","lime","rock-salt","ammonia","carbon-dioxide","trona","hydrogen","sulfur","tin-ore","coke","bauxite","caustic-soda","charcoal","timber","chlorine","trichlorosilane","nitrogen","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["satellite"],"steps":[{"name":"Sort the cells","process":"inspect","text":"Each finished cell goes through a sorter, which tests it under simulated sunlight and groups it by electrical performance.","inputs":["solar-cell"]},{"name":"Wash the front glass","process":"wash","text":"A glass washer rinses and dries the sheet that will face the sun. A station then cuts EVA film, a clear encapsulating plastic, and lays it on top.","inputs":["glass","plastic"]},{"name":"Solder cells into strings","process":"weld","text":"A stringer machine solders thin copper ribbons over the busbars of each cell and links them in rows. Silicon cracks easily, so the soldering is tuned to keep heat and mechanical stress down.","inputs":["copper","solder"]},{"name":"Bus the strings together","process":"weld","text":"A layup station places the strings on the film. Bus ribbons are soldered across them to finish the circuit and bring out the output leads. Inspectors look it over and measure its dark current behavior.","inputs":["copper"]},{"name":"Stack the back layers","process":"laminate","text":"More EVA and a protective back sheet are cut to length and placed over the circuit. Some designs use a second layer of glass at the rear. Automatic placement holds position to within a tenth of a millimeter.","inputs":["plastic"],"spec":"±0.1 mm"},{"name":"Laminate under heat","process":"laminate","text":"In a chamber with vacuum and pressure control, the stack is heated until the milky EVA cross-links into a clear plastic that bonds cells, glass and back sheet for good.","inputs":[],"spec":"around 140 °C"},{"name":"Trim the edges","process":"cut","text":"Excess film and back sheet are cut away around the edge of the cured laminate.","inputs":[]},{"name":"Add the junction box","process":"assemble","text":"A junction box goes on the rear with bypass diodes, which route current around broken or shaded cells, and the output cables.","inputs":["copper-wire"]},{"name":"Press on the frame","process":"assemble","text":"At a frame press, an edge gasket or a bead of silicone goes on and an aluminum frame closes around the laminate. It adds stiffness and makes the module easier to install.","inputs":["aluminum","silicone"]},{"name":"Flash test the output","process":"inspect","text":"A sun simulator, or flasher, fires a light at the module and records its electrical performance. Electroluminescence imaging looks for flaws in the cells.","inputs":[]},{"name":"Check isolation and grade","process":"inspect","text":"A high-voltage test measures the insulation between circuit and frame, and the frame's ground connection is checked. After a final visual check, modules are rated by output and packaged.","inputs":[]}],"facts":["Within ten years the silicon used per watt-peak declined from 16 grams to 6 grams.","In that time the thickness of a silicon wafer fell from 300 micrometers to about 160 to 190.","Solid-state PV systems often last anywhere from 10 to 30 years."],"where":[],"whereNote":null,"sources":[{"title":"How Do You Make Solar Modules?","url":"https://www.solarpowerworldonline.com/2013/04/what-goes-into-making-a-solar-module/"},{"title":"How crystalline solar modules are manufactured","url":"https://presse.surplex.com/pressreleases/how-crystalline-solar-modules-are-manufactured-insights-into-the-production-process-3374129"},{"title":"Photovoltaic module","url":"https://en.wikipedia.org/wiki/Photovoltaic_module"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"solder","name":"Solder","kind":"material","category":"metals","title":"How solder is made","url":"https://assemblyline.org/make/solder","stations":6,"upstream":19,"downstream":54,"depth":4,"dek":"Solder is a metal blend chosen to melt below the parts it joins, and one classic mix melts at a single sharp temperature.","answer":"Solder is a fusible alloy, usually tin with lead, or tin with silver and copper in the lead-free versions. The metals are melted together in precise proportions and cast into bars, which are extruded or drawn into wire. Wire for electronics is often hollow, with a core of flux that cleans the joint as it melts.","aka":["soft solder","lead-free solder","tin-lead solder","solder wire"],"inputs":["tin","lead","silver","copper"],"uses":["hearing-aid","pacemaker","printed-circuit-board","led-bulb","solid-state-drive","solar-panel","refrigerator","drone","electric-guitar","trumpet","air-conditioner","flute","saxophone","stained-glass","smoke-detector","eyeglass-frame","smartwatch","wireless-earbuds","phone-charger","usb-cable","microphone","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush"],"grounds":["tin-ore","lead-ore","silver-ore","zinc-ore","copper-ore","water","air","coal","sulfur","limestone"],"upstreamSlugs":["tin","lead","silver","copper","tin-ore","coke","lead-ore","zinc","silver-ore","zinc-ore","copper-ore","sulfuric-acid","lime","water","oxygen","air","coal","sulfur","limestone"],"downstreamSlugs":["hearing-aid","pacemaker","printed-circuit-board","led-bulb","solid-state-drive","solar-panel","refrigerator","drone","electric-guitar","trumpet","air-conditioner","flute","saxophone","stained-glass","smoke-detector","eyeglass-frame","smartwatch","wireless-earbuds","phone-charger","usb-cable","microphone","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","thermometer","ev-battery","smartphone","laptop","television","hard-drive","computer-keyboard","computer-mouse","wind-turbine","microwave-oven","washing-machine","satellite","car","electric-car","airbag","airplane","rocket","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","digital-camera","e-reader","skyscraper"],"steps":[{"name":"Melt the metals together","process":"melt","text":"Tin is melted with its partner metals. In classic soft solder that is lead, in amounts from 5 to 70 percent tin by weight, and in the modern lead-free solders it is silver and copper. More tin makes the joint stronger.","inputs":["tin","lead"]},{"name":"Set the recipe exactly","process":"mix","text":"The proportions decide the melting behavior. The eutectic mix of 61.9 percent tin and 38.1 percent lead melts at one point, 183 °C, instead of over a range. Lead-free tin-silver-copper alloys became standard after rules took effect in the EU on July 1, 2006.","inputs":["silver","copper"],"spec":"183 °C for tin-lead eutectic"},{"name":"Cast into bars","process":"cast","text":"The alloy is cast into bars. Plumbers use thick bars of solder and apply flux separately.","inputs":[]},{"name":"Draw it into wire","process":"draw","text":"Bars are reduced to solder wire, with diameters from ultra-fine 0.25 to 0.5 millimeters to heavy gauge 1.5 to 2.0 millimeters and above.","inputs":[]},{"name":"Fill it with flux","process":"assemble","text":"Wire for hand soldering is often made with cores of flux. Flux strips oxide from the metal surfaces as the joint heats, so that the molten solder can wet them.","inputs":[]},{"name":"Spool it up","process":"package","text":"Wire is wound onto spools of a convenient weight. Solder is also sold as paste, as thin sheets for jewelers, and as preformed foil shapes.","inputs":[]}],"facts":["Soft solder melts between 90 and 450 °C, and alloys that melt between 180 and 190 °C are the most commonly used.","Since 1974, lead has been prohibited in solder and flux for drinking-water plumbing in the United States.","Lead-tin solder easily dissolves gold plating and forms brittle intermetallic compounds."],"where":[],"whereNote":null,"sources":[{"title":"Solder","url":"https://en.wikipedia.org/wiki/Solder"},{"title":"Tin","url":"https://en.wikipedia.org/wiki/Tin"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"solid-state-drive","name":"Solid-state drive","kind":"product","category":"electronics","title":"How solid-state drives are made","url":"https://assemblyline.org/make/solid-state-drive","stations":6,"upstream":67,"downstream":2,"depth":9,"dek":"An SSD has no moving parts, just flash chips and a small processor running firmware.","answer":"A solid-state drive is a small circuit board carrying flash memory chips and a controller. Machines solder the parts on, the board is loaded with firmware that decides where every file lives, and the drive is tested under heavy loads. Aluminum or plastic cases enclose it for installation.","aka":["SSD","flash drive","NVMe drive"],"inputs":["printed-circuit-board","solder","memory-chip","microchip","aluminum"],"uses":["laptop","game-console"],"grounds":["crude-oil","coal","copper-ore","water","air","silica-sand","limestone","tin-ore","lead-ore","silver-ore","zinc-ore","quartz","gold-ore","bauxite","sulfur","rock-salt","trona","natural-gas","corn","timber","sugarcane","sugar-beet"],"upstreamSlugs":["printed-circuit-board","solder","memory-chip","microchip","aluminum","copper","fiberglass","epoxy","photoresist","tin","lead","silver","silicon-wafer","nitrogen","oxygen","gold","crude-oil","coal","petroleum-coke","alumina","copper-ore","water","air","sulfuric-acid","silica-sand","limestone","soda-ash","phenol","propylene","acetone","chlorine","caustic-soda","phenolic-resin","tin-ore","coke","lead-ore","zinc","silver-ore","zinc-ore","lime","polysilicon","quartz","argon","gold-ore","bauxite","sulfur","rock-salt","ammonia","carbon-dioxide","trona","benzene","naphtha","formaldehyde","silicon","hydrochloric-acid","trichlorosilane","hydrogen","natural-gas","corn","yeast","toluene","methanol","charcoal","timber","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["laptop","game-console"],"steps":[{"name":"Print solder on the board","process":"print","text":"A stencil deposits solder paste on the pads of a bare circuit board.","inputs":["printed-circuit-board","solder"]},{"name":"Place flash and controller","process":"assemble","text":"Pick-and-place machines set flash memory chips and the controller on the paste. The controller is an embedded processor that runs firmware.","inputs":["memory-chip","microchip"]},{"name":"Bake to melt the solder","process":"weld","text":"The board travels through a reflow oven, and the paste melts into joints that hold every part.","inputs":[]},{"name":"Load the firmware","process":"assemble","text":"Firmware is written to the controller. It spreads writes across all cells to even out wear and manages how data moves between the host and the flash.","inputs":[]},{"name":"Stress-test the drive","process":"inspect","text":"Drives are filled and read back repeatedly, since flash cells wear out after a limited number of program-erase cycles.","inputs":[]},{"name":"Enclose the drive","process":"assemble","text":"The board is fitted into a case sized to match the connector standard.","inputs":["aluminum"]}],"facts":["Flash cells store between one and four bits each, from single-level to quad-level cells.","SSDs do not suffer from mechanical failure, yet firmware bugs are one major cause of data loss.","Since 2009, most SSDs have used NAND flash instead of volatile DRAM."],"where":[],"whereNote":null,"sources":[{"title":"Solid-state drive","url":"https://en.wikipedia.org/wiki/Solid-state_drive"},{"title":"Flash memory","url":"https://en.wikipedia.org/wiki/Flash_memory"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sour-cream","name":"Sour cream","kind":"product","category":"food","title":"How sour cream is made","url":"https://assemblyline.org/make/sour-cream","stations":7,"upstream":2,"downstream":0,"depth":2,"dek":"Sour cream is cream that bacteria thicken in about 18 hours, until its pH falls from 6.5 to 4.6.","answer":"Dairies adjust cream to the right fat level, stir in stabilizers, homogenize it so the fat droplets are tiny, and pasteurize it. Then they cool the cream, add lactic acid bacteria and leave it to ferment for about 18 hours in the tub. The acid thickens the cream, and it is chilled before it ships.","aka":["soured cream"],"inputs":["raw-milk","cream"],"uses":[],"grounds":["raw-milk"],"upstreamSlugs":["raw-milk","cream"],"downstreamSlugs":[],"steps":[{"name":"Set the fat level","process":"mix","text":"Cream is standardized so the finished product meets the legal minimum. In the United States that is at least 18 percent milk fat before any bulking ingredients are added.","inputs":["raw-milk","cream"],"spec":"at least 18% milk fat"},{"name":"Stir in stabilizers","process":"mix","text":"Whey solids and stabilizers such as modified starch, guar gum or carrageenan go in. They give a smooth gel and help stop the watery layer that can weep out of the tub when it gets shaken in transit.","inputs":[]},{"name":"Break the fat into specks","process":"mix","text":"A homogenizer forces the cream through a narrow gap so the fat globules shatter into specks below 2 microns. Smaller globules make a thicker, whiter, creamier product that does not separate.","inputs":[]},{"name":"Pasteurize the cream","process":"pasteurize","text":"Heat kills harmful bacteria and clears the field for the starter culture. It also denatures whey proteins, and those stick to the fat globules and add to the thick texture.","inputs":[]},{"name":"Cool and add culture","process":"chill","text":"The cream is cooled to a temperature where mesophilic bacteria thrive and seeded with a small dose of active starter culture, 1 to 2 percent of the batch.","inputs":[],"spec":"20 °C"},{"name":"Let it sour in the tub","process":"ferment","text":"The inoculated cream is portioned into its packages and left to ferment. Bacteria turn milk sugar into lactic acid. At a pH near 4.6 the casein proteins clump into a gel and the cream sets.","inputs":[],"spec":"18 hours, pH 6.5 to 4.6"},{"name":"Chill the sealed tubs","process":"chill","text":"A last cooling stops fermentation. The sealed product must stay refrigerated from then on.","inputs":[]}],"facts":["Sour cream is only partly fermented, which is why it still has to be refrigerated.","Milk protein sets into a gel when the pH reaches about 4.6, the same threshold that curdles milk into cheese and yogurt.","An unopened tub of sour cream can last 1 to 2 weeks past its sell-by date."],"where":[],"whereNote":null,"sources":[{"title":"Sour cream","url":"https://en.wikipedia.org/wiki/Sour_cream"},{"title":"Cheese","url":"https://en.wikipedia.org/wiki/Cheese"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sourdough","name":"Sourdough bread","kind":"product","category":"food","title":"How sourdough bread is made","url":"https://assemblyline.org/make/sourdough","stations":6,"upstream":28,"downstream":0,"depth":9,"dek":"Sourdough is raised by a living jar of wild yeast and bacteria that bakers feed like a pet.","answer":"A starter of flour and water is fed until a stable culture of wild yeast and lactic bacteria takes hold. A portion of that starter is mixed into fresh flour, water and salt, and the dough rises slowly while the bacteria make lactic acid, which gives sourdough its tang. The dough is shaped and baked with steam.","aka":["sourdough loaf","naturally leavened bread"],"inputs":["flour","water","table-salt"],"uses":[],"grounds":["water","wheat","rock-salt","seawater","air","corn","natural-gas","sugarcane","sugar-beet","limestone","crude-oil"],"upstreamSlugs":["flour","water","table-salt","wheat","vitamin-c","rock-salt","seawater","corn-starch","hydrogen","air","sugar","plastic-bottle","corn","natural-gas","sugarcane","sugar-beet","lime","pet-plastic","limestone","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","crude-oil","yeast","molasses"],"downstreamSlugs":[],"steps":[{"name":"Grow the starter","process":"ferment","text":"Flour and water are mixed and kept warm for a week or two. Natural enzymes break flour starch into sugars, which wild yeast and bacteria eat.","inputs":["flour","water"]},{"name":"Feed it fresh flour","process":"mix","text":"Bakers add flour and water to the starter every day to keep the culture active. In a bakery the starter is fed several hours before it goes into dough. When it turns bubbly and floats in water, it is ready.","inputs":["flour","water"],"spec":"fed 4 to 12 hours before use"},{"name":"Mix the final dough","process":"mix","text":"A portion of the active starter is mixed with fresh flour, water and salt. The starter usually weighs 13 to 25 percent of the flour.","inputs":["flour","water","table-salt"],"spec":"starter at 13 to 25% of flour weight"},{"name":"Rise slowly","process":"ferment","text":"Yeast produces carbon dioxide and a little ethanol while the bacteria make lactic and acetic acid. The acids give the sour taste, and they also slow staling. Warmer, wetter starters make more lactic acid and cooler, drier ones more acetic.","inputs":[]},{"name":"Shape the loaves","process":"mold","text":"The risen dough is divided and shaped into loaves, then given a final rise.","inputs":[]},{"name":"Bake with steam","process":"bake","text":"Heat makes steam inside the dough, which inflates it further, and the surface browns into a crust.","inputs":[]}],"facts":["One of the oldest sourdough breads known dates to 3700 BC and was found in Switzerland.","Sourdough was the main way to leaven bread for most of history. Baker's yeast has only been around for under 150 years.","Some modern bakeries use starters made from isolated microbes grown in fermentors, then packaged as baker's products."],"where":[],"whereNote":null,"sources":[{"title":"Sourdough","url":"https://en.wikipedia.org/wiki/Sourdough"},{"title":"Bread","url":"https://en.wikipedia.org/wiki/Bread"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"soy-milk","name":"Soy milk","kind":"product","category":"food","title":"How soy milk is made","url":"https://assemblyline.org/make/soy-milk","stations":6,"upstream":2,"downstream":0,"depth":1,"dek":"Soy milk is tofu before it sets, made by grinding soaked beans in about ten times their weight in water.","answer":"Dry soybeans are soaked, then ground wet with plenty of water into a slurry. The slurry is boiled to sterilize it and disable a bean enzyme that causes a grassy off-flavor. A strainer removes the pulp, and the milk is blended with vitamins and sweetener before it goes into cartons for long shelf life.","aka":["soya milk","soymilk","soy drink"],"inputs":["soybeans","water"],"uses":[],"grounds":["soybeans","water"],"upstreamSlugs":["soybeans","water"],"downstreamSlugs":[],"steps":[{"name":"Soak the beans","process":"mix","text":"Dry soybeans sit in water for at least three hours, sometimes overnight, until they swell. The longer a soak runs in cool water, the more time an enzyme has to turn bean fat into a grassy-smelling compound.","inputs":["soybeans"],"spec":"3 hours or longer"},{"name":"Grind them wet","process":"crush","text":"The swollen beans are ground with added water into a thick purée. Traditional soy milk uses ten parts water to one part beans by weight, which leaves a protein content between 1 and 4 percent.","inputs":["water"],"spec":"10 parts water to 1 part beans"},{"name":"Boil the slurry","process":"cook","text":"The purée is held at or near boiling. Heat sterilizes it, switches off a protein that blocks digestion and deactivates the enzyme behind the beany smell. Factories add an anti-foaming agent at this stage because soy foams hard.","inputs":[],"spec":"15 to 20 minutes"},{"name":"Strain out the pulp","process":"separate","text":"A filter or strainer removes the insoluble fiber, leaving a smooth white liquid. The leftover pulp is a by-product that is sold on for other uses.","inputs":[]},{"name":"Sweeten and fortify","process":"mix","text":"Sweeteners, flavors and added vitamins and minerals are blended in to make the product behave more like dairy milk.","inputs":[]},{"name":"Seal in cartons","process":"fill","text":"Finished soy milk is sold in plastic bottles or plastic-coated cartons such as Tetra Pak. Those cartons are what gave soy milk a long shelf life and let it spread worldwide.","inputs":[]}],"facts":["Soy milk first entered the English language as soy-bean milk in an 1897 report from the US Department of Agriculture.","Cornell researchers worked out in 1966 that an enzyme called lipoxygenase causes soy milk's beany flavor, then built a process to remove it.","In Qing dynasty China, cooks found that heating soy milk gently for at least 90 minutes broke down sugars that cause gas."],"where":[],"whereNote":null,"sources":[{"title":"Soy milk","url":"https://en.wikipedia.org/wiki/Soy_milk"},{"title":"Oat milk","url":"https://en.wikipedia.org/wiki/Oat_milk"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"soy-sauce","name":"Soy sauce","kind":"product","category":"food","title":"How soy sauce is made","url":"https://assemblyline.org/make/soy-sauce","stations":7,"upstream":8,"downstream":0,"depth":2,"dek":"Soy sauce is brewed for months by a mold that digests soybeans and wheat into amino acids.","answer":"Soybeans are cooked and wheat is roasted and crushed, then mixed and seeded with koji mold. After the mold grows, the culture goes into salt brine and ferments for months, while enzymes break proteins into amino acids and starches into sugars. The mash is pressed, the liquid is pasteurized, and the sauce is bottled.","aka":["shoyu","soya sauce","tamari"],"inputs":["soybeans","water","wheat","koji","table-salt"],"uses":[],"grounds":["soybeans","water","wheat","rice","rock-salt","seawater"],"upstreamSlugs":["soybeans","water","wheat","koji","table-salt","rice","rock-salt","seawater"],"downstreamSlugs":[],"steps":[{"name":"Soak and cook the beans","process":"cook","text":"Soybeans are soaked in water and then steamed or boiled until soft. Heat unfolds the proteins so mold enzymes can attack them later.","inputs":["soybeans","water"]},{"name":"Roast and crush the wheat","process":"bake","text":"Wheat is roasted and cracked. The roasting gives the sauce its toasty aroma, and the wheat starch will later turn into sugars.","inputs":["wheat"]},{"name":"Seed with koji mold","process":"grow","text":"Equal amounts of cooked soybeans and roasted wheat are mixed and sprinkled with spores of Aspergillus oryzae or Aspergillus sojae. The mold spreads through the grain in warm, humid rooms for a few days and makes enzymes.","inputs":[]},{"name":"Drown it in brine","process":"ferment","text":"The mold-covered grain, called koji, is mixed into strong salt brine to make a thick mash called moromi. Salt keeps spoilage bacteria out while the right microbes do the work.","inputs":["koji","table-salt","water"]},{"name":"Brew for months","process":"ferment","text":"Mold enzymes break the grain proteins into free amino acids and the starches into simple sugars. Lactic acid bacteria and yeast then work on the sugars and add acids, alcohol and many flavor compounds. Traditional soy sauce takes months.","inputs":[],"spec":"months"},{"name":"Press out the liquid","process":"press","text":"The mash is wrapped in cloth-lined containers and squeezed. Raw soy sauce runs out, and the solid cake that is left is used for animal feed or fertilizer.","inputs":[]},{"name":"Heat and bottle","process":"pasteurize","text":"The raw sauce is heated to kill remaining yeast and mold, then filtered. It is aged or bottled directly.","inputs":[]}],"facts":["Soy sauce began as a way to stretch salt, which used to be expensive.","The Dutch East India Company listed soy sauce as a commodity in 1737, when seventy-five large barrels shipped from Dejima, Japan, to Batavia.","Some cheaper soy sauces are made by chemically hydrolyzing soy protein, and some blend both methods."],"where":[],"whereNote":null,"sources":[{"title":"Soy sauce","url":"https://en.wikipedia.org/wiki/Soy_sauce"},{"title":"Tofu","url":"https://en.wikipedia.org/wiki/Tofu"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"soybeans","name":"Soybeans","kind":"raw","category":"farm","title":"How soybeans are grown and harvested","url":"https://assemblyline.org/make/soybeans","stations":3,"upstream":0,"downstream":168,"depth":0,"dek":"Brazil and the United States together grow two-thirds of the world's soybeans, a crop that feeds its own soil.","answer":"Soybeans are planted in straight rows with modern machinery in places with hot summers, where the best growth comes at mean temperatures of 20 to 30 degrees Celsius. Weeds and pests are kept down through the season. When the pods mature, mechanized harvesters gather the crop, and like other legumes the plants fix nitrogen in the soil.","aka":["soya beans","soy","soybean farming","soybean harvest"],"inputs":[],"uses":["vegetable-oil","soy-sauce","tofu","chocolate","soy-milk","koji"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["vegetable-oil","soy-sauce","tofu","chocolate","soy-milk","koji","soap","shampoo","deodorant","sunscreen","mascara","detergent","ink","glycerin","cast-iron-pan","margarine","mayonnaise","peanut-butter","tortilla","donut","sandwich-cookie","potato-chips","french-fries","canned-tuna","chicken-nuggets","baby-formula","oat-milk","crackers","fish-sticks","biodiesel","wooden-spoon","pencil-eraser","modeling-clay","cake-mix","foundation-makeup","candy-coated-chocolate","sake","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","toothpaste","chewing-gum","snow-globe","cough-syrup","gelatin-capsule","diesel","vacuum-cleaner","electric-kettle","cotton-candy","pillow","paint","condensed-milk","coconut-milk","canned-meat","canned-soup","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","car","electric-car","nitrile-glove","washing-machine","paperclip","corn-flakes","popcorn","crayon","fireworks","candle","salsa","zip-bag","blender","dishwasher","cotton-swab","mouthwash","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","locomotive","refrigerator","microwave-oven","pencil","scissors","mirror","airplane","container-ship","shipping-container","bicycle","motorcycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","toy-car","coil-spring","hammer","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","padlock"],"steps":[{"name":"Plant in straight rows","process":"grow","text":"Seed goes into moist, organic-rich soil with machinery. Growth stalls when temperatures drop below 20 °C or rise above 40 °C, and the best conditions are mean temperatures of 20 to 30 °C.","inputs":[],"spec":"20 to 30 °C"},{"name":"Control weeds and pests","process":"grow","text":"Weeds and pests must be kept in check to protect the crop. Deer and groundhogs both feed on the plants, and deer alone can cut yields by as much as 15%.","inputs":[]},{"name":"Harvest the mature pods","process":"harvest","text":"Each hairy pod is 3 to 8 cm long and holds two to four seeds. After maturity, mechanized harvesting machines gather the crop.","inputs":[]}],"facts":["Raw soybeans, even the green immature form, are toxic to all monogastric animals until they are cooked, roasted or fermented.","Brazil's soybean boom rests partly on a cultivar developed in the 1980s that grows well at low latitudes."],"where":[{"place":"Brazil and the United States combined","share":"66% of world output"}],"whereNote":"2020, share of the more than 353 million tonnes of soybeans produced worldwide.","sources":[{"title":"Soybean","url":"https://en.wikipedia.org/wiki/Soybean"},{"title":"Combine harvester","url":"https://en.wikipedia.org/wiki/Combine_harvester"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"spandex","name":"Spandex","kind":"material","category":"textiles","title":"How spandex is made","url":"https://assemblyline.org/make/spandex","stations":6,"upstream":25,"downstream":3,"depth":5,"dek":"A strand can stretch to five times its length and snap back. It began as a search for a better girdle.","answer":"Heat would wreck this fiber, so it cannot be melted and squirted out like nylon. Chemists instead link stiff and floppy segments into a polyurethane chain, dissolve the polymer, and draw the solution through spinnerets while the solvent evaporates. The floppy segments stretch and the stiff ones pull everything back into shape.","aka":["elastane","Lycra"],"inputs":["benzene","formaldehyde","chlorine","ethylene-glycol"],"uses":["underwear","leggings","swimsuit"],"grounds":["air","water","rock-salt","crude-oil","natural-gas","coal","sulfur","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["benzene","formaldehyde","chlorine","ethylene-glycol","naphtha","hydrogen","toluene","methanol","air","water","rock-salt","sulfuric-acid","ethylene","oxygen","carbon-dioxide","crude-oil","natural-gas","coal","sulfur","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["underwear","leggings","swimsuit"],"steps":[{"name":"Make the stiff isocyanate","process":"react","text":"Aniline and formaldehyde are joined, then treated with phosgene in closed plants to make MDI, the diisocyanate behind almost all of this fiber. Its ring-shaped units will become the hard sections of the chain.","inputs":["benzene","formaldehyde","chlorine"]},{"name":"Build the floppy diol","process":"react","text":"Tetrahydrofuran is polymerized with an acid catalyst into long, limp chains with an alcohol group at each end. Ester diols made from adipic acid and glycols are the other option, and they hold up better in chlorinated water.","inputs":[]},{"name":"Join hard and soft segments","process":"react","text":"The long diols react with the diisocyanate and a short dialcohol such as ethylene glycol. The polymer ends up as alternating rigid and flexible blocks. Diamines then extend the chains.","inputs":["ethylene-glycol"]},{"name":"Dissolve instead of melting","process":"mix","text":"The polymer degrades if it melts, so the usual route for synthetic fiber is closed. It is made into a concentrated solution, thick enough to hold together as it leaves a fine hole.","inputs":[]},{"name":"Spin through hot air","process":"spin","text":"The solution is drawn through spinnerets at a temperature where the solvent evaporates. What is left in the air is a solid, rubbery filament.","inputs":[]},{"name":"Wind it for the mills","process":"package","text":"Filament is wound up and sent to textile mills. There it is usually mixed with cotton or polyester and makes up a small percentage of the cloth, so the fabric keeps the look of the other fibers.","inputs":[]}],"facts":["An estimated 80% of clothing sold in the United States contained spandex in 2010.","A fabric with as little as 5% spandex cannot go through most mechanical recycling machines.","DuPont's Lycra was originally called Fiber K."],"where":[],"whereNote":null,"sources":[{"title":"Spandex","url":"https://en.wikipedia.org/wiki/Spandex"},{"title":"Spandex (Britannica)","url":"https://www.britannica.com/technology/spandex"},{"title":"Methylene diphenyl diisocyanate","url":"https://en.wikipedia.org/wiki/Methylene_diphenyl_diisocyanate"},{"title":"Polytetrahydrofuran","url":"https://en.wikipedia.org/wiki/Polytetrahydrofuran"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"spark-plug","name":"Spark plug","kind":"product","category":"machines","title":"How spark plugs are made","url":"https://assemblyline.org/make/spark-plug","stations":8,"upstream":33,"downstream":0,"depth":5,"dek":"A spark heats its path through the cylinder to 60,000 kelvins, while ceramic keeps the voltage inside the plug.","answer":"A spark plug has a threaded steel shell, a ceramic insulator and a central electrode. The insulator is pressed from ceramic powder and fired hard. Steel is pressed through dies into a shell, a nickel alloy tip is added, and threads are rolled on. The shell is shrunk tight around the insulator and the tip is bent over to set the gap.","aka":["sparking plug","engine plug"],"inputs":["alumina","steel","nickel","copper"],"uses":[],"grounds":["bauxite","water","nickel-ore","copper-ore","air","rock-salt","limestone","iron-ore","dolomite","manganese-ore","natural-gas","sulfur","coal","quartz","timber","crude-oil"],"upstreamSlugs":["alumina","steel","nickel","copper","bauxite","caustic-soda","lime","water","pig-iron","magnesium","steel-scrap","oxygen","manganese","argon","nickel-ore","sulfuric-acid","copper-ore","air","rock-salt","limestone","iron-ore","coke","dolomite","silicon","propane","manganese-ore","natural-gas","sulfur","coal","quartz","charcoal","timber","crude-oil"],"downstreamSlugs":[],"steps":[{"name":"Press the insulator","process":"press","text":"Ceramic powder is packed in a mold under pressure and ground to the long shape of the insulator. It will have to stand thousands of volts and high heat.","inputs":["alumina"]},{"name":"Fire it hard","process":"fire","text":"The insulators are fired in a kiln to a dense ceramic body that does not conduct electricity.","inputs":[]},{"name":"Form the steel shell","process":"forge","text":"Raw steel is pressed repeatedly into dies until it reaches the final hex-topped shape.","inputs":["steel"]},{"name":"Attach the side tip","process":"weld","text":"A straight nickel alloy tip is fixed to the end of the shell. It will become the side electrode.","inputs":["nickel"]},{"name":"Roll the threads","process":"roll","text":"The shell passes through threaded rollers that emboss the threads that screw into a cylinder head.","inputs":[]},{"name":"Seat the center electrode","process":"assemble","text":"An electrode running the whole length of the insulator is pressed in, with a nickel-alloy skin and a copper core.","inputs":["nickel","copper"]},{"name":"Shrink the shell on","process":"assemble","text":"Oil helps the shell slide over the insulator. A shrinking tool then passes electric current through the metal so it grips the ceramic tight.","inputs":[]},{"name":"Bend the tip over","process":"press","text":"Bending brings the nickel tip within a few thousandths of an inch of the center electrode, and the spark jumps this space.","inputs":[]}],"facts":["The spark channel inside the cylinder reaches a temperature of 60,000 K.","NGK, which describes itself as the world's leading spark plug maker, began as a company that made ceramics."],"where":[],"whereNote":null,"sources":[{"title":"Spark plug","url":"https://en.wikipedia.org/wiki/Spark_plug"},{"title":"Spark plug, Britannica","url":"https://www.britannica.com/technology/spark-plug"},{"title":"Hows It's Made: Spark Plugs","url":"https://www.chevyhardcore.com/?p=9193"},{"title":"The ignition hero that's been firing engines for over a century","url":"https://ngkntk.com/newsroom/blog/emea/the-ignition-hero-thats-been-firing-engines-for-over-a-century"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sparkling-water","name":"Sparkling water","kind":"product","category":"drink","title":"How sparkling water is made","url":"https://assemblyline.org/make/sparkling-water","stations":6,"upstream":60,"downstream":0,"depth":9,"dek":"Carbonation works best near freezing, because cold water holds far more gas than warm water.","answer":"Sparkling water is plain water that has been chilled and forced to dissolve carbon dioxide gas under pressure. A little mineral salt is often added to mimic natural spring water and offset the acidity of the dissolved gas. It is sealed straight away so the gas stays dissolved until the cap comes off.","aka":["seltzer","soda water","club soda","carbonated water"],"inputs":["water","baking-soda","carbon-dioxide","aluminum-can","glass-bottle","plastic-bottle"],"uses":[],"grounds":["water","trona","limestone","rock-salt","natural-gas","corn","silica-sand","air","crude-oil","coal","sugarcane","sugar-beet","bauxite","soybeans","rapeseed","clay","titanium-ore","iron-ore","sulfur"],"upstreamSlugs":["water","baking-soda","carbon-dioxide","aluminum-can","glass-bottle","plastic-bottle","trona","limestone","ammonia","rock-salt","soda-ash","natural-gas","corn","yeast","aluminum","ink","epoxy","silica-sand","polyethylene","pet-plastic","air","lime","molasses","crude-oil","coal","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","phenol","propylene","acetone","chlorine","caustic-soda","ethylene","p-xylene","ethylene-glycol","sugarcane","sugar-beet","bauxite","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","coke","oxygen","sulfuric-acid","iron-ore","sulfur","benzene","naphtha","hydrogen","methanol","toluene"],"downstreamSlugs":[],"steps":[{"name":"Filter the source water","process":"separate","text":"Water is filtered and treated so nothing in it changes the taste. Mineral waters may instead come direct from a spring.","inputs":["water"]},{"name":"Dose in mineral salts","process":"mix","text":"Many brands add sodium bicarbonate, potassium bicarbonate or similar salts. They imitate the flavor of natural mineral water and offset the acid that forms when carbon dioxide dissolves.","inputs":["baking-soda"]},{"name":"Chill almost to freezing","process":"chill","text":"Cold water dissolves much more gas, so the water is cooled to just above its freezing point before carbonating.","inputs":[]},{"name":"Inject pressurized gas","process":"mix","text":"Carbon dioxide is injected into the water under pressure. Higher pressure and lower temperature push more gas into the liquid. Some of the gas reacts with the water to form weak carbonic acid, which gives a slight tartness.","inputs":["carbon-dioxide"]},{"name":"Fill under pressure","process":"fill","text":"Bottles and cans are filled and sealed immediately so the pressure stays up. Opening the container releases the pressure and the dissolved gas forms bubbles.","inputs":["aluminum-can","glass-bottle","plastic-bottle"]},{"name":"Check and crate","process":"inspect","text":"Fill levels, seals and pressure are checked on the line. Good containers are grouped into trays or cases for shipping.","inputs":[]}],"facts":["Joseph Priestley discovered a way to make carbonated water in 1767 by hanging a bowl of water above a beer vat in Leeds.","Sparkling mineral water is slightly more erosive to teeth than still water, but about 1% as corrosive as soft drinks.","The first large factory for artificial mineral water was built in 1781 by Thomas Henry of Manchester."],"where":[],"whereNote":null,"sources":[{"title":"Carbonated water","url":"https://en.wikipedia.org/wiki/Carbonated_water"},{"title":"Soft drink","url":"https://en.wikipedia.org/wiki/Soft_drink"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"spodumene","name":"Spodumene","kind":"raw","category":"ground","title":"How spodumene is mined","url":"https://assemblyline.org/make/spodumene","stations":3,"upstream":0,"downstream":13,"depth":0,"dek":"Spodumene is a lithium rock so tightly bound that it has to be roasted before acid can pry the lithium out.","answer":"Spodumene is a lithium mineral so plentiful at Greenbushes in Western Australia that it often makes up half the rock in the lithium zone. Crews drill and blast open pits, grade and stockpile the ore, and feed it to plants that upgrade it by gravity, heavy media, flotation and magnets. The concentrate is later roasted to make the lithium reachable.","aka":["lithium pegmatite","SC6"],"inputs":[],"uses":["lithium-carbonate"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["lithium-carbonate","lithium-ion-cell","ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","electric-car"],"steps":[{"name":"Blast the pegmatite pit","process":"mine","text":"Mining targets the fresh, unweathered parts of the pegmatite exposed in open pits, using ordinary drill and blast. At Greenbushes the lithium zone runs over 2 km long.","inputs":[]},{"name":"Grade and stockpile","process":"separate","text":"Broken ore is sorted into stockpiles by grade and mineral makeup, so the plants get a known feed. Waste rock is trucked to set areas on site, shaped and replanted.","inputs":[]},{"name":"Upgrade by density and froth","process":"separate","text":"Plants combine gravity, heavy-media, flotation and magnetic steps to raise the lithium content. Different operating modes give technical and chemical grades. The widely traded concentrate, SC6, holds around 6% lithium oxide. Lithium stays tightly bound in the crystal until a chemical plant roasts it.","inputs":[],"spec":"around 6% lithium oxide"}],"facts":["Spodumene concentrate with around 6% lithium oxide is shipped for making lithium-ion battery materials.","The mineral comes in gem varieties as well, the pink to lilac kunzite and the green hiddenite.","Tin mining began at Greenbushes in 1888, nearly a century before its first lithium plant opened in 1983."],"where":[{"place":"Australia","share":"leading lithium-producing country since 2020"}],"whereNote":"Ranking by lithium mined, as reported for 2020 and after.","sources":[{"title":"Greenbushes (Talison Lithium)","url":"https://www.talisonlithium.com/greenbushes-project"},{"title":"Spodumene","url":"https://en.wikipedia.org/wiki/Spodumene"},{"title":"Lithium","url":"https://en.wikipedia.org/wiki/Lithium"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sprinkles","name":"Sprinkles","kind":"product","category":"food","title":"How sprinkles are made","url":"https://assemblyline.org/make/sprinkles","stations":6,"upstream":25,"downstream":1,"depth":5,"dek":"Sprinkles come in two builds: rods squeezed from sugar paste, and round nonpareils grown layer by layer in a spinning drum.","answer":"Rod-shaped sprinkles start as a doughy paste of sugar, cornstarch, cocoa and an emulsifier, pushed through an extruder with holes like an angel hair pasta die. The strands fall on a vibrating conveyor that shakes them into short lengths. They are still soft, so a spray of color and a sugar glaze harden them. Round nonpareils are built up in drums instead.","aka":["jimmies","hundreds and thousands","nonpareils","hagelslag"],"inputs":["sugar","corn-starch","cocoa-powder","corn-syrup","pigment"],"uses":["donut"],"grounds":["sugarcane","sugar-beet","water","corn","cocoa-beans","iron-ore","sulfur","limestone","titanium-ore","crude-oil","air","rock-salt","coal"],"upstreamSlugs":["sugar","corn-starch","cocoa-powder","corn-syrup","pigment","sugarcane","sugar-beet","water","lime","corn","cocoa-beans","iron-ore","titanium-dioxide","carbon-black","sulfur","limestone","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","crude-oil","air","rock-salt","coal"],"downstreamSlugs":["donut"],"steps":[{"name":"Stir a stiff paste","process":"mix","text":"Sugar, cornstarch, cocoa and an emulsifier combine into a doughy paste, with a little corn syrup and food-grade wax in the recipe.","inputs":["sugar","corn-starch","cocoa-powder","corn-syrup"]},{"name":"Push through tiny holes","process":"extrude","text":"An extruder forces the paste through very small holes, and it comes out like strands of angel hair pasta.","inputs":[]},{"name":"Shake into lengths","process":"cut","text":"The strands drop onto a vibrating conveyor belt, which breaks them into the right range of sizes.","inputs":[]},{"name":"Spray on the color","process":"coat","text":"At this stage the pieces are still very soft. A spray coat of color starts to harden them.","inputs":["pigment"]},{"name":"Glaze for shine","process":"coat","text":"A coat of sugar glaze makes them shiny and durable enough to survive the bag.","inputs":["sugar"]},{"name":"Bag them","process":"package","text":"Finished sprinkles are bagged for bakers and shoppers.","inputs":[]}],"facts":["Dutch hagelslag, the chocolate sprinkles eaten on buttered bread, was invented in 1913 and is named for hail.","Hagelslag may only be sold as chocoladehagelslag if it has a cacao percentage of more than 32%.","In Australia and New Zealand, nonpareils on buttered white bread are a children's party food called fairy bread.","In the Boston area, chocolate sprinkles are called jimmies, and the origin of the name is uncertain."],"where":[],"whereNote":null,"sources":[{"title":"Food Republic: What are sprinkles made of?","url":"https://www.foodrepublic.com/2013/03/12/what-are-sprinkles-made"},{"title":"Sprinkles","url":"https://en.wikipedia.org/wiki/Sprinkles"},{"title":"Dragée","url":"https://en.wikipedia.org/wiki/Dragée"},{"title":"Confectionery","url":"https://en.wikipedia.org/wiki/Confectionery"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"stained-glass","name":"Stained glass","kind":"product","category":"minerals","title":"How stained glass is made","url":"https://assemblyline.org/make/stained-glass","stations":10,"upstream":49,"downstream":0,"depth":5,"dek":"The color runs all the way through most stained glass, thanks to metal oxides stirred into the melt.","answer":"Metal oxides stirred into molten glass give it color right through, and the melt is then blown or rolled into sheets. Studios draw a full-size cartoon, score and break each piece to fit, and fire on any painted detail. The pieces slot into H-shaped lead came, joints get soldered, and a linseed-oil cement brushed under the lead seals the panel.","aka":["colored glass window","leaded glass"],"inputs":["silica-sand","soda-ash","limestone","lead","solder","linseed-oil","steel","copper"],"uses":[],"grounds":["silica-sand","limestone","rock-salt","water","trona","lead-ore","flax","copper-ore","air","natural-gas","corn","coal","zinc-ore","tin-ore","silver-ore","iron-ore","dolomite","manganese-ore","sulfur","quartz","timber","crude-oil","sugarcane","sugar-beet"],"upstreamSlugs":["silica-sand","soda-ash","limestone","lead","solder","linseed-oil","steel","copper","rock-salt","water","ammonia","carbon-dioxide","lime","trona","lead-ore","coke","zinc","tin","silver","flax","pig-iron","magnesium","steel-scrap","oxygen","manganese","argon","copper-ore","air","sulfuric-acid","natural-gas","corn","yeast","coal","zinc-ore","tin-ore","silver-ore","iron-ore","dolomite","silicon","propane","manganese-ore","sulfur","molasses","quartz","charcoal","timber","crude-oil","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Melt in the colors","process":"melt","text":"Silica and fluxes melt in a pot with metal oxides, which color the batch all the way through. Makers call the result pot metal.","inputs":["silica-sand","soda-ash","limestone"]},{"name":"Form the sheets","process":"blow","text":"A glassmaker blows a gather into a cylinder or spins it into a crown, or molten glass is poured on a table and rolled flat. Flashed sheets carry a thin colored layer fused to another color or to colorless glass.","inputs":[]},{"name":"Draw the cartoon","process":"print","text":"The approved design is drawn at full scale in several copies, often now with CAD software. These cartoons act as templates for cutting and for assembly.","inputs":[]},{"name":"Score and break","process":"cut","text":"A glass cutter scores each piece to the pattern, and hands, tapping or breaking pliers snap it along the line. Grozing pliers and grinders then tidy edges for a snug fit.","inputs":[]},{"name":"Paint and fire detail","process":"fire","text":"Where the design calls for shading or imagery, vitreous paint of powdered glass and pigment goes on. A kiln then fuses it permanently to the surface.","inputs":[]},{"name":"Lead up the panel","process":"assemble","text":"The pieces are laid over the cartoon and slotted into H-shaped lead came, held by horseshoe nails while the work grows. Cames are woven in both directions, since long straight runs make a weak spot.","inputs":["lead"]},{"name":"Flux and solder","process":"weld","text":"Each lead joint is fluxed with tallow, then soldered with tin and lead on both sides.","inputs":["solder"]},{"name":"Brush in the cement","process":"coat","text":"A putty of calcium carbonate and boiled linseed oil is forced under the lead flanges with a brush. It seals the panel, adds strength and protects the metal.","inputs":["linseed-oil"]},{"name":"Clean and polish","process":"grind","text":"Excess cement is cleaned away and the panel is buffed, leaving the lead with a rich patina.","inputs":[]},{"name":"Add the steel supports","process":"assemble","text":"Thin steel strips can hide inside the lead for rigidity, and larger panels get external bars tied on with copper wire, set into the frame behind lead lines.","inputs":["steel","copper"]}],"facts":["In crown glass, a bubble of glass is spun, and the centrifugal force flattens it into a disc.","The lead came in a stained glass window is usually worth replacing after about 100 years.","Red glass is often flashed because enough colorant for the red to develop makes a full-thickness sheet far too dark."],"where":[],"whereNote":null,"sources":[{"title":"Stained glass","url":"https://en.wikipedia.org/wiki/Stained_glass"},{"title":"How Traditional Stained Glass Is Made, Ultraviolet Stained Glass","url":"https://www.ultravioletstainedglass.com/post/stained-glass-construction-a-definitive-guide"},{"title":"Traditional methods and materials, Somerset Stained Glass","url":"https://www.somersetstainedglass.co.uk/methods.html"},{"title":"Stained Glass: How It's Made, Daedalian Glass Studios","url":"https://www.daedalianglassstudios.com/stained-glass-production/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"stainless-steel","name":"Stainless steel","kind":"material","category":"metals","title":"How stainless steel is made","url":"https://assemblyline.org/make/stainless-steel","stations":7,"upstream":33,"downstream":20,"depth":6,"dek":"Stainless steel does rust, but only in its outer few layers of atoms, and the chromium under it stops the rest.","answer":"Stainless steel is melted from scrap and chromium-rich alloys in an electric arc furnace, then moved to a vessel where argon and oxygen are blown through it to burn out carbon. It is cast into slabs, hot-rolled into coils, pickled in acid, and cold-rolled and annealed to the final thickness and finish.","aka":["inox","rustless steel","corrosion-resistant steel"],"inputs":["steel-scrap","chromium","nickel","oxygen","argon"],"uses":["syringe","washing-machine","electric-kettle","wristwatch","kitchen-knife","fork","razor-blade","elevator","fountain-pen","thermos","water-bottle","pressure-cooker","blender","dishwasher","ice-skates","golf-club","asthma-inhaler","subway-train","smartwatch"],"grounds":["chromite","limestone","air","water","nickel-ore","natural-gas","crude-oil","coal","rock-salt","trona","sulfur","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["steel-scrap","chromium","nickel","oxygen","argon","propane","chromite","coke","soda-ash","limestone","air","water","aluminum","nickel-ore","sulfuric-acid","natural-gas","crude-oil","coal","rock-salt","ammonia","carbon-dioxide","lime","trona","petroleum-coke","alumina","sulfur","corn","yeast","bauxite","caustic-soda","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["syringe","washing-machine","electric-kettle","wristwatch","kitchen-knife","fork","razor-blade","elevator","fountain-pen","thermos","water-bottle","pressure-cooker","blender","dishwasher","ice-skates","golf-club","asthma-inhaler","subway-train","smartwatch","skyscraper"],"steps":[{"name":"Arc-melt scrap and alloys","process":"melt","text":"Stainless scrap, ordinary steel scrap and alloys rich in chromium, nickel and molybdenum are melted together by electric arcs. The chromium is the point. Ferritic grades carry 10.5 to 27 percent of it, and austenitic grades add nickel.","inputs":["steel-scrap","chromium","nickel"]},{"name":"Burn off carbon with argon","process":"refine","text":"The molten metal is poured into a second vessel where argon and oxygen are blown through it. Carbon leaves as carbon monoxide gas, while the chromium stays in the metal, and the final chemistry is adjusted. Before this process arrived in the 1950s and 1960s, large tonnages were costly to make.","inputs":["oxygen","argon"]},{"name":"Cast slabs and blooms","process":"cast","text":"Continuous casters freeze the steel into slabs for flat products, typically about 20 centimeters thick and 2 meters wide, or into blooms for bars and wire rod.","inputs":[]},{"name":"Reheat and hot-roll","process":"roll","text":"Slabs go back into a furnace, then through hot-rolling mills that squeeze them to coils about 3 millimeters thick. Blooms are rolled into bars or coiled wire rod.","inputs":[]},{"name":"Pickle off the scale","process":"wash","text":"Hot rolling leaves a layer of dark oxide on the strip. The coils run through acid baths that dissolve it, exposing clean metal.","inputs":[]},{"name":"Cold-roll and anneal","process":"roll","text":"The clean coil is rolled again at room temperature in multi-roll Sendzimir mills, then annealed in a protective atmosphere so the surface does not re-oxidize. Rolling and annealing are repeated until it hits the thickness and finish the buyer wants.","inputs":[]},{"name":"Slit, polish and form","process":"cut","text":"Finished coils are slit into narrower strips or formed into tube. Bars are straightened and machined, and wire rod goes to drawing machines.","inputs":[]}],"facts":["Harry Brearley found a corrosion-resistant steel in 1913 while looking for a better gun-barrel alloy in Sheffield.","The austenitic family, which includes the common 304 and 316 grades, makes up about two-thirds of all stainless steel.","A scratch on stainless steel heals itself, because the chromium film re-forms whenever oxygen reaches the bare metal."],"where":[],"whereNote":null,"sources":[{"title":"Stainless steel","url":"https://en.wikipedia.org/wiki/Stainless_steel"},{"title":"Ferrochrome","url":"https://en.wikipedia.org/wiki/Ferrochrome"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"fork","name":"Stainless steel fork","kind":"product","category":"hardware","title":"How stainless steel forks are made","url":"https://assemblyline.org/make/fork","stations":8,"upstream":34,"downstream":0,"depth":7,"dek":"Forks were scorned as an unmanly Italian affectation when they reached England.","answer":"A stainless steel fork is punched from a strip of steel. A cross-rolling press thins and widens the head, a trimming die cuts the outline and the tines, and an embossing die strikes the handle pattern. The flat fork is ground and polished, pressed into its curve, polished again and cleaned of wax.","aka":["table fork","dinner fork"],"inputs":["stainless-steel"],"uses":[],"grounds":["chromite","limestone","air","water","nickel-ore","natural-gas","crude-oil","coal","rock-salt","trona","sulfur","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["stainless-steel","steel-scrap","chromium","nickel","oxygen","argon","propane","chromite","coke","soda-ash","limestone","air","water","aluminum","nickel-ore","sulfuric-acid","natural-gas","crude-oil","coal","rock-salt","ammonia","carbon-dioxide","lime","trona","petroleum-coke","alumina","sulfur","corn","yeast","bauxite","caustic-soda","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Blank the outline","process":"stamp","text":"A die cuts a rough fork-shaped piece from a strip of stainless steel. It is still thick and has no shape to speak of.","inputs":["stainless-steel"]},{"name":"Roll the head thin","process":"roll","text":"Machines press the blank thin and long, spreading the wider head.","inputs":[],"spec":"0.8-2mm thick"},{"name":"Trim out the tines","process":"cut","text":"A trimming die punches the final outline and clips the wide head into separate tines.","inputs":[]},{"name":"Emboss the handle","process":"stamp","text":"A die strikes the handle's shape, its pattern and any logo into the flat piece.","inputs":[]},{"name":"Grind off burrs","process":"grind","text":"Machines grind the edges and sides, then flat-polish the faces to take off rough material.","inputs":[]},{"name":"Press the curve","process":"press","text":"A hydraulic press squeezes the still-flat fork between dies, which give it the bend of its head and handle.","inputs":[]},{"name":"Buff to a shine","process":"grind","text":"Soft wheels and polishing compound work over the surface and sides, by machine or by hand, for a bright or satin finish.","inputs":[]},{"name":"Clean off the wax","process":"wash","text":"An ultrasonic bath strips polishing wax and other residue before inspection and packing.","inputs":[]}],"facts":["A bronze fork from the 16th century BC was found in a Mycenaean Greek grave.","Thomas Coryat described forks in English in 1611, and many English people called them an unmanly Italian affectation.","One cutlery maker puts a fork through 16 steps, including polishing between each tine."],"where":[],"whereNote":null,"sources":[{"title":"Fork","url":"https://en.wikipedia.org/wiki/Fork"},{"title":"Stamping (metalworking)","url":"https://en.wikipedia.org/wiki/Stamping_(metalworking)"},{"title":"How Stainless-Steel Cutlery is Produced?","url":"https://garboflatware.com/news/how-stainless-steel-cutlery-is-produced.html"},{"title":"An Introduction into How Cutlery is Made","url":"https://studiowilliam.com/an-introduction-into-how-cutlery-is-made/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"water-bottle","name":"Stainless steel water bottle","kind":"product","category":"hardware","title":"How stainless steel water bottles are made","url":"https://assemblyline.org/make/water-bottle","stations":7,"upstream":74,"downstream":0,"depth":10,"dek":"Many steel bottles begin as a straight tube of metal that is inflated with water pressure into a bottle shape.","answer":"A stainless steel tube is cut to length and placed in a water expander, where huge pressure swells it into a bottle with no base. Inner and outer bottles are necked, threaded and cleaned, then nested and welded to a bottom plate. Air is pumped from the gap between them, and the bottle is polished, coated and tested.","aka":["insulated bottle","steel flask","vacuum bottle"],"inputs":["stainless-steel","paint"],"uses":[],"grounds":["water","chromite","limestone","air","nickel-ore","titanium-ore","iron-ore","sulfur","natural-gas","crude-oil","coal","rock-salt","trona","corn","bauxite","tin-ore","sugarcane","soybeans","rapeseed","clay","dolomite","manganese-ore","sugar-beet","quartz","timber"],"upstreamSlugs":["stainless-steel","paint","steel-scrap","chromium","nickel","oxygen","argon","water","titanium-dioxide","pigment","acrylic","tin-can","propane","chromite","coke","soda-ash","limestone","air","aluminum","nickel-ore","sulfuric-acid","titanium-ore","chlorine","iron-ore","carbon-black","sulfur","propylene","ammonia","methanol","tinplate","lacquer","ink","natural-gas","crude-oil","coal","rock-salt","carbon-dioxide","lime","trona","petroleum-coke","alumina","naphtha","steel","tin","ethanol","vegetable-oil","phenolic-resin","corn","yeast","bauxite","caustic-soda","hydrogen","pig-iron","magnesium","manganese","tin-ore","sugarcane","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","molasses","dolomite","silicon","manganese-ore","benzene","sugar-beet","quartz","charcoal","timber","toluene"],"downstreamSlugs":[],"steps":[{"name":"Cut the steel tube","process":"cut","text":"Raw stainless steel tube is cut to the length needed for the inner or outer bottle.","inputs":["stainless-steel"]},{"name":"Inflate with water pressure","process":"blow","text":"The tube is clamped in a water expander and filled with water under enormous pressure. The wall swells outward into a bottle shape, with no bottom yet.","inputs":[]},{"name":"Neck and thread the top","process":"forge","text":"A press forms the shoulder, a machine squeezes the top into a neck, and a threading machine rolls threads for the cap. The edges are then trimmed and smoothed.","inputs":[]},{"name":"Clean the shells","process":"wash","text":"Ultrasonic cleaning removes oil and dust so the surfaces are clean and dry before assembly.","inputs":[]},{"name":"Nest and weld the bottom","process":"weld","text":"The inner bottle is pressed inside the outer one, a round bottom plate is added, and the outer bottle and plate are welded. A water test then checks the welds.","inputs":[]},{"name":"Pump out the gap","process":"separate","text":"The space between inner and outer walls is evacuated. This vacuum stops heat from conducting across and keeps the outside of a hot bottle comfortable to hold.","inputs":[]},{"name":"Polish, coat and test","process":"coat","text":"The outer surface is polished, then powder-coated or painted. Logos are printed, and sample bottles are tested for leaks, insulation and drops.","inputs":["paint"]}],"facts":["A water-expanded steel bottle comes out with no bottom, so a round plate has to be welded on before it can hold anything.","One water expansion tube can yield two outer shells, which are then cut apart."],"where":[],"whereNote":null,"sources":[{"title":"Manufacturing Process: How Metal Water Bottle Is Manufactured?","url":"https://www.everich.com/how-metal-water-bottle-is-manufactured/"},{"title":"Stainless steel","url":"https://en.wikipedia.org/wiki/Stainless_steel"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"staple","name":"Staple","kind":"product","category":"hardware","title":"How staples are made","url":"https://assemblyline.org/make/staple","stations":6,"upstream":48,"downstream":0,"depth":8,"dek":"A strip of office staples starts as rows of flattened zinc-coated wires, glued side by side and then bent into a U.","answer":"Thick zinc-coated steel wire is drawn thin and rolled flat. Rows of flat wires are glued side by side into a wide band, and an oven cures the glue. A forming machine bends the band into a U and cuts it into strips of connected staples, which are polished and boxed.","aka":["office staple","paper staple","stapler staples"],"inputs":["steel-wire","zinc","adhesive"],"uses":[],"grounds":["zinc-ore","air","water","sulfur","crude-oil","iron-ore","limestone","dolomite","manganese-ore","natural-gas","rock-salt","coal","quartz","timber"],"upstreamSlugs":["steel-wire","zinc","adhesive","steel","zinc-ore","air","sulfuric-acid","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","sulfur","ethylene","propylene","ammonia","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","naphtha","benzene","rock-salt","coal","quartz","charcoal","timber","toluene"],"downstreamSlugs":[],"steps":[{"name":"Draw the coated wire","process":"draw","text":"Low-carbon steel wire coated with zinc so it will not rust in a drawer is pulled through dies until it reaches size. Copper-plated and stainless versions exist but are rarer.","inputs":["steel-wire","zinc"]},{"name":"Roll the wire flat","process":"roll","text":"Rollers press the round wire into a thin flat ribbon, so each staple has a flat crown and legs.","inputs":[]},{"name":"Glue wires side by side","process":"laminate","text":"Dozens of flat wires run in parallel while glue coats them. An oven cures the glue, giving a wide flat band.","inputs":["adhesive"],"spec":"80 to 120 parallel wires"},{"name":"Bend into U shapes","process":"stamp","text":"A forming die bends the band, so that each wire becomes a staple with a crown across the top and two legs.","inputs":[]},{"name":"Cut into strips","process":"cut","text":"Blades cut the band at fixed intervals, and each length is a strip of connected staples. A full strip holds 210 staples.","inputs":[],"spec":"210 staples per full strip"},{"name":"Polish and box","process":"package","text":"Strips are polished to take off burrs, checked for bent staples, and stacked in boxes ready for the stapler's magazine.","inputs":[]}],"facts":["Staple sizes like 24/6 give the wire gauge first and the leg length in millimeters second.","The home stapler was developed by Henry Heyl in 1877.","Large dovetail staples from the 6th century BC have been found holding stone together in Persian buildings."],"where":[],"whereNote":null,"sources":[{"title":"Staple (fastener)","url":"https://en.wikipedia.org/wiki/Staple_(fastener)"},{"title":"Stapler","url":"https://en.wikipedia.org/wiki/Stapler"},{"title":"How Are Staples Made? Staple Manufacturing Process & Core Equipment","url":"https://www.grsjixie.com/news/how-are-staples-made-staple-manufacturing-process-core-equipment/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"steel","name":"Steel","kind":"material","category":"metals","title":"How steel is made","url":"https://assemblyline.org/make/steel","stations":6,"upstream":24,"downstream":156,"depth":4,"dek":"A blast of pure oxygen burns the carbon out of molten iron in under 40 minutes and turns it into steel.","answer":"Most steel starts as molten pig iron poured into a vessel called a converter. A water-cooled lance blows nearly pure oxygen onto the metal, burning off excess carbon and other impurities, while lime collects them as slag. The steel is tapped into a ladle, adjusted with alloys, and cast into a continuous red-hot strand that is cut into slabs.","aka":["carbon steel","structural steel","basic oxygen steel"],"inputs":["pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon"],"uses":["toothbrush","lithium-ion-cell","ev-battery","aa-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","inkjet-printer","electric-toothbrush"],"grounds":["iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","coal","quartz","timber","crude-oil","sulfur"],"upstreamSlugs":["pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","coal","quartz","charcoal","timber","crude-oil","sulfur"],"downstreamSlugs":["toothbrush","lithium-ion-cell","ev-battery","aa-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","inkjet-printer","electric-toothbrush","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-car","refrigerator","microwave-oven","washing-machine","blender","air-conditioner","treadmill","game-console","graphics-card","phone-charger","safety-pin","car","airbag","ceiling-fan","water-heater","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","concrete","skyscraper","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sailboat","action-figure","power-outlet","champagne","electric-kettle","pencil","mirror","golf-ball","wallpaper","wooden-chair","water-bottle","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","snow-globe","neon-sign","aluminum-window-frame","toffee"],"steps":[{"name":"Strip the sulfur from the iron","process":"react","text":"Hot metal from the blast furnace is poured into a ladle. If the steel must be clean, a lance pushes several hundred kilograms of powdered magnesium into the iron, and the sulfur turns into a crust that is raked off.","inputs":["pig-iron","magnesium"]},{"name":"Tip it into the converter","process":"fill","text":"The converter is a tilting vessel lined with heat-proof brick. Scrap steel, about 25 to 30 percent of the load, goes in first, then the liquid iron. The ratio matters, because the scrap has to be melted by the heat the process itself makes.","inputs":["steel-scrap"]},{"name":"Blow in pure oxygen","process":"react","text":"The vessel is stood upright and a water-cooled lance with a copper tip goes down to within a few feet of the bath. It blows oxygen of about 99 percent purity at supersonic speed. The carbon ignites, the temperature rises to about 1700 °C, and lime added alongside it forms slag that absorbs the impurities.","inputs":["oxygen","lime"],"spec":"about 20 minutes of blowing"},{"name":"Tap it into a ladle","process":"separate","text":"The vessel is tilted and the steel pours through a tap hole into a ladle, leaving the slag behind to be dumped into pots. A sample is taken first, since the carbon content must now be a few tenths of a percent.","inputs":[]},{"name":"Alloy and degas in the ladle","process":"refine","text":"The ladle is where the grade is set. Manganese and other alloying elements are added, oxygen and dissolved gases are removed, and argon or nitrogen is bubbled up from below to stir the alloys in evenly.","inputs":["manganese","argon"]},{"name":"Cast a continuous strand","process":"cast","text":"The ladle empties through a holding bath called a tundish into an open-bottomed, water-cooled copper mold. A skin freezes on the strand while the middle is still liquid. Rollers pull it down and around a curve, and torches cut it into slabs, blooms or billets.","inputs":[],"spec":"up to 1.4 m of slab per minute"}],"facts":["A modern oxygen converter turns up to 400 tons of iron into steel in less than 40 minutes, where an open-hearth furnace needed 10 to 12 hours.","More than 95 percent of the world's steel is now cast through a continuous caster, not poured into individual ingot molds.","To strip sulfur from molten iron, steelmakers lance several hundred kilograms of powdered magnesium into it, in a violent reaction that gives off heat."],"where":[],"whereNote":null,"sources":[{"title":"Steelmaking","url":"https://en.wikipedia.org/wiki/Steelmaking"},{"title":"Basic oxygen steelmaking","url":"https://en.wikipedia.org/wiki/Basic_oxygen_steelmaking"},{"title":"Continuous casting","url":"https://en.wikipedia.org/wiki/Continuous_casting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"chain","name":"Steel chain","kind":"product","category":"hardware","title":"How steel chain is made","url":"https://assemblyline.org/make/chain","stations":7,"upstream":26,"downstream":0,"depth":6,"dek":"Each link is bent from a rod, threaded through the one before it, and only then welded shut.","answer":"Wire is lubricated and drawn through a die until thin and strong. A machine cuts a length, passes it through the last link and bends it around a form with its arms, closing a new link. The cut is welded shut. The whole chain then runs through a coil to 940 °C, is quenched in water, reheated more gently and cooled again, and is finally calibrated to exact link size.","aka":["link chain","lifting chain"],"inputs":["steel-wire"],"uses":[],"grounds":["iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","coal","quartz","timber","crude-oil","sulfur"],"upstreamSlugs":["steel-wire","steel","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","coal","quartz","charcoal","timber","crude-oil","sulfur"],"downstreamSlugs":[],"steps":[{"name":"Draw the wire","process":"draw","text":"Wire unwinds from a coil, passes a lubricant box and is pulled through a die narrower than itself onto a rotating drum, which thins and strengthens it.","inputs":["steel-wire"]},{"name":"Cut to link length","process":"cut","text":"The straightened wire is sheared by a steel cutter into pieces sized for one link.","inputs":[]},{"name":"Bend through the last link","process":"press","text":"The piece passes through the previous link, and arms force it around a form. The machine turns the new link upright, and the cycle repeats.","inputs":[]},{"name":"Weld the cut shut","process":"weld","text":"A welder closes the join in each link, so the strand holds together under load.","inputs":[]},{"name":"Harden in water","process":"heat-treat","text":"A heating coil brings the whole chain up to orange heat, and it drops into water. The sudden change in temperature makes the steel hard and brittle.","inputs":[],"spec":"940 °C"},{"name":"Temper for toughness","process":"heat-treat","text":"A second coil reheats the chain to a lower temperature before another water cooling, giving back some elasticity.","inputs":[]},{"name":"Calibrate the strand","process":"inspect","text":"Following heat treatment the strand is calibrated to the right geometry. High grades get a mild final heating that relieves the stress calibration leaves behind.","inputs":[]}],"facts":["The Tibetan siddha Thangtong Gyalpo built chain bridges in eastern Bhutan in 1433.","Wire rope grew out of wrought iron chains because a flaw in one link can break the whole chain, while a flaw in one wire matters much less.","A chain is floppy when you push it but acts like a rigid rod when you pull it."],"where":[],"whereNote":null,"sources":[{"title":"Gigazine: How chains are made","url":"https://www.gigazine.net/gsc_news/en/20171231-process-of-making-chains"},{"title":"US patent 6782689: Method of making a chain","url":"https://patents.google.com/patent/US6782689"},{"title":"Chain","url":"https://en.wikipedia.org/wiki/Chain"},{"title":"Suspension bridge","url":"https://en.wikipedia.org/wiki/Suspension_bridge"},{"title":"Steel wire","url":"https://en.wikipedia.org/wiki/Steel_wire"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"steel-beam","name":"Steel I-beam","kind":"product","category":"metals","title":"How steel I-beams are made","url":"https://assemblyline.org/make/steel-beam","stations":6,"upstream":25,"downstream":2,"depth":5,"dek":"An I-beam puts steel where bending stress is highest and leaves out the middle, where it would do almost nothing.","answer":"Most I-beams are rolled in one piece. A hot steel bloom is run back and forth through a structural mill, where grooved rolls squeeze it step by step into a shape with a vertical web between two flanges. Very large sections are instead fabricated by welding steel plates together into a plate girder.","aka":["I-beam","H-beam","wide-flange beam","rolled steel joist","universal beam"],"inputs":["steel"],"uses":["skyscraper","locomotive"],"grounds":["iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","coal","quartz","timber","crude-oil","sulfur"],"upstreamSlugs":["steel","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","coal","quartz","charcoal","timber","crude-oil","sulfur"],"downstreamSlugs":["skyscraper","locomotive"],"steps":[{"name":"Cast a bloom","process":"cast","text":"Molten steel is cast into a bloom, a thick block that is the usual starting point for large structural sections. Steel for beams must be consistent all the way through, since a beam carries load in its flanges.","inputs":["steel"]},{"name":"Soak it to rolling heat","process":"heat-treat","text":"The bloom is held in a furnace until it is hot all the way through. If it is rolled while cold in the middle, it can crack and tear.","inputs":[]},{"name":"Break it down in the blooming mill","process":"roll","text":"Heavy reversing rolls squash the bloom, pass after pass, rolling forward and back. The cross-section shrinks and the piece gets longer, ready for the shaping mill.","inputs":[]},{"name":"Form the web and flanges","process":"roll","text":"In the structural mill, grooved rolls squeeze the steel into a shape like the letter I, a thin upright web joined at top and bottom to wide flanges. Each pass cuts a slightly more finished profile.","inputs":[]},{"name":"Cut to length","process":"cut","text":"The beam is trimmed to the length ordered. Because a beam is rolled hot, uneven cooling can leave stresses in shapes whose thickness varies, so it is left to cool carefully.","inputs":[]},{"name":"Weld up the giants","process":"weld","text":"Where a span needs a section bigger than any mill can roll, plates are welded, and sometimes bolted or riveted, into a plate girder. It has the same I-shape, assembled from flat steel.","inputs":["steel"]}],"facts":["The first rolled I-beam, made from one piece of wrought iron, was patented in 1849 by Alphonse Halbou of Forges de la Providence in Belgium.","In a beam, the web resists shear forces and the flanges resist most of the bending."],"where":[],"whereNote":null,"sources":[{"title":"I-beam","url":"https://en.wikipedia.org/wiki/I-beam"},{"title":"Hot rolling","url":"https://en.wikipedia.org/wiki/Hot_rolling"},{"title":"Continuous casting","url":"https://en.wikipedia.org/wiki/Continuous_casting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"steel-pipe","name":"Steel pipe","kind":"product","category":"hardware","title":"How steel pipe is made","url":"https://assemblyline.org/make/steel-pipe","stations":7,"upstream":28,"downstream":3,"depth":6,"dek":"Steel pipe is either a flat strip curled and welded shut, or a solid billet pushed over a spike until it is hollow.","answer":"Welded steel pipe starts as a coil of flat steel. Rollers curl it into a tube and an electric current welds the seam as it passes. Weld-free pipe is different: a hot solid billet is drawn over a piercing rod to hollow it out. Either way the pipe is cut to length and tested.","aka":["welded pipe","ERW pipe"],"inputs":["sheet-steel","steel","zinc"],"uses":["container-ship","treadmill","wheelbarrow"],"grounds":["zinc-ore","air","iron-ore","limestone","dolomite","water","manganese-ore","natural-gas","sulfur","coal","quartz","timber","crude-oil"],"upstreamSlugs":["sheet-steel","steel","zinc","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","iron-ore","coke","limestone","dolomite","silicon","propane","water","manganese-ore","natural-gas","sulfur","coal","quartz","charcoal","timber","crude-oil"],"downstreamSlugs":["container-ship","treadmill","wheelbarrow"],"steps":[{"name":"Uncoil the strip","process":"roll","text":"A coil of flat steel is unrolled and its edges are trimmed square. The coil is the feedstock for the continuous welded route.","inputs":["sheet-steel"]},{"name":"Curl it into a tube","process":"roll","text":"Set after set of rollers bend the flat strip, a little further each time, until the two edges meet in a straight seam.","inputs":[]},{"name":"Weld the seam","process":"weld","text":"Electric current runs through the edges of the strip, often by an induction coil around the tube. The steel resists the current, heats and fuses along the seam without any filler metal.","inputs":[]},{"name":"Size and cut","process":"cut","text":"Final rollers true up the diameter, and a flying saw cuts the endless tube to length without stopping the line.","inputs":[]},{"name":"Pierce a billet instead","process":"forge","text":"For weld-free pipe, a solid billet is heated and drawn over a piercing rod in a process called rotary piercing, which opens a hole down its center with no welding.","inputs":["steel"]},{"name":"Test under pressure","process":"inspect","text":"Each heat of pipe is checked for chemical composition and strength, and finished lengths are pressure tested.","inputs":[]},{"name":"Dip in zinc","process":"coat","text":"Pipe for water or outdoor use may go through a galvanizing bath that coats it in zinc.","inputs":["zinc"]}],"facts":["Early steel pipes were riveted and later clamped, and by the early 1930s welding had replaced both methods.","The schedule numbers on pipe, such as Sch 40, were set long ago for steel pipe and carried over to PVC."],"where":[],"whereNote":null,"sources":[{"title":"Pipe (fluid conveyance)","url":"https://en.wikipedia.org/wiki/Pipe_(fluid_conveyance)"},{"title":"Electric resistance welding","url":"https://en.wikipedia.org/wiki/Electric_resistance_welding"},{"title":"Hot-dip galvanizing","url":"https://en.wikipedia.org/wiki/Hot-dip_galvanizing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"steel-scrap","name":"Steel scrap","kind":"material","category":"metals","title":"How steel scrap is recycled","url":"https://assemblyline.org/make/steel-scrap","stations":5,"upstream":5,"downstream":167,"depth":2,"dek":"A shredder can tear a whole car into fist-size chunks, and a magnet picks out the steel.","answer":"Steel scrap comes from worn-out cars, appliances, buildings and factory offcuts. Yards sort it, then a shredder tears mixed items into small pieces so magnets can pull the steel out of the plastic, copper and aluminum. Electric arc furnaces then melt it, at temperatures that reach 1,800 °C.","aka":["scrap steel","ferrous scrap","recycled steel"],"inputs":["oxygen","propane"],"uses":["steel","stainless-steel","rebar","cast-iron-pan"],"grounds":["air","natural-gas","crude-oil"],"upstreamSlugs":["oxygen","propane","air","natural-gas","crude-oil"],"downstreamSlugs":["steel","stainless-steel","rebar","cast-iron-pan","toothbrush","lithium-ion-cell","ev-battery","aa-battery","television","hard-drive","wind-turbine","electric-motor","transformer","vacuum-cleaner","wristwatch","sheet-steel","tinplate","steel-wire","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","elevator","skateboard","drum-kit","rubiks-cube","wine-barrel","dishwasher","office-chair","ski","snowboard","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","harmonica","saxophone","toy-car","dental-floss","wheelchair","barbed-wire","hammer","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","eyeglass-frame","usb-cable","loudspeaker","inkjet-printer","electric-toothbrush","syringe","washing-machine","electric-kettle","kitchen-knife","fork","razor-blade","fountain-pen","thermos","water-bottle","pressure-cooker","blender","asthma-inhaler","smartwatch","concrete","skyscraper","smartphone","laptop","drone","satellite","wireless-earbuds","digital-camera","e-reader","electric-car","refrigerator","microwave-oven","air-conditioner","treadmill","game-console","graphics-card","phone-charger","safety-pin","car","airbag","ceiling-fan","water-heater","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","paperclip","needle","tire","guitar","electric-guitar","piano","violin","ballpoint-pen","clothespin","staple","sofa","dartboard","slinky","cello","guitar-string","bolt","chain","coil-spring","chain-link-fence","light-switch","suspension-bridge-cable","mattress","roller-skates","wine","bourbon","scotch","cognac","port-wine","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sailboat","action-figure","power-outlet","champagne","pencil","mirror","golf-ball","wallpaper","wooden-chair","tennis-racket","bowling-ball","billiard-ball","dice","fashion-doll","snow-globe","neon-sign","aluminum-window-frame","toffee"],"steps":[{"name":"Collect the worn-out steel","process":"harvest","text":"Scrap comes from end-of-life vehicles, structural steel, white goods and offcuts left from making new products. Scrapyards usually pay by weight.","inputs":[]},{"name":"Torch-cut the heavy pieces","process":"cut","inputs":["oxygen","propane"],"text":"Beams, plate and other pieces too big for a shredder are sliced apart with a cutting torch, which burns a fuel gas in pure oxygen and then burns through the steel itself."},{"name":"Shred the mixed items","process":"crush","text":"Cars and appliances mix steel with plastic, copper, aluminum and brass. A shredder breaks them into small pieces so the metals can be separated mechanically instead of by hand.","inputs":[]},{"name":"Pull out steel with magnets","process":"separate","text":"Magnets lift the steel away from the rest. Non-magnetic metals go on to separate sorting, and what is left is the shredded steel stream.","inputs":[]},{"name":"Sort and bale for the mill","process":"package","text":"Scrap is graded by type and packed into forms a furnace can take. It is sold to mills that melt it into new steel.","inputs":[]}],"facts":["Mini-mills that melt scrap cost far less to build than integrated mills, around US$140 to 200 per ton of annual capacity against US$1,000.","An electric arc furnace melts scrap with an arc struck from graphite electrodes, at temperatures up to 1,800 °C."],"where":[],"whereNote":null,"sources":[{"title":"Scrap","url":"https://en.wikipedia.org/wiki/Scrap"},{"title":"Electric arc furnace","url":"https://en.wikipedia.org/wiki/Electric_arc_furnace"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"steel-wire","name":"Steel wire","kind":"material","category":"metals","title":"How steel wire is made","url":"https://assemblyline.org/make/steel-wire","stations":7,"upstream":25,"downstream":67,"depth":5,"dek":"Steel wire is a rod pulled through a series of ever-smaller holes, getting longer each time and never changing volume.","answer":"Steel wire is made by pulling hot-rolled steel rod through a row of ever-narrower dies. The metal cannot lose volume, so as it thins it gets longer, and each pull cuts its cross-section by 15 to 45 percent. Lubricant keeps it smooth, and heating between pulls keeps it from snapping.","aka":["drawn steel wire","carbon steel wire"],"inputs":["steel"],"uses":["washing-machine","wire-rope","nail","screw","paperclip","safety-pin","needle","ball-bearing","tire","bicycle","guitar","electric-guitar","piano","violin","drum-kit","ballpoint-pen","clothespin","staple","dishwasher","sofa","dartboard","slinky","cello","guitar-string","bolt","hinge","chain","coil-spring","barbed-wire","chain-link-fence","light-switch","suspension-bridge-cable","mattress"],"grounds":["iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","coal","quartz","timber","crude-oil","sulfur"],"upstreamSlugs":["steel","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","coal","quartz","charcoal","timber","crude-oil","sulfur"],"downstreamSlugs":["washing-machine","wire-rope","nail","screw","paperclip","safety-pin","needle","ball-bearing","tire","bicycle","guitar","electric-guitar","piano","violin","drum-kit","ballpoint-pen","clothespin","staple","dishwasher","sofa","dartboard","slinky","cello","guitar-string","bolt","hinge","chain","coil-spring","barbed-wire","chain-link-fence","light-switch","suspension-bridge-cable","mattress","elevator","sailboat","scissors","rubiks-cube","ice-skates","action-figure","harmonica","power-outlet","suitcase","high-heels","eyeglass-frame","loudspeaker","game-console","graphics-card","electric-motor","locomotive","motorcycle","skateboard","roller-skates","yo-yo","car","electric-car","wheelbarrow","padlock","skyscraper","refrigerator","microwave-oven","vacuum-cleaner","drone","blender","air-conditioner","treadmill","subway-train","inkjet-printer"],"steps":[{"name":"Roll the rod","process":"roll","text":"Billets of steel are hot-rolled in a rod mill into a coiled rod. This is the raw material for every wire drawer.","inputs":["steel"]},{"name":"Clean and lubricate","process":"wash","text":"Wire rod is cleaned of scale and coated with a lubricant. Without it the die would rub the surface raw and wear out fast. Some wire is dipped in copper sulfate solution so a copper film forms, and in dry drawing the rod passes through a container of lubricant that coats it.","inputs":[]},{"name":"Point the end and thread it","process":"machine","text":"The tip of the rod is shrunk by hammering, filing or rolling so that it will fit through the first die. A worker threads it through, and the machine's drum grips the end.","inputs":[]},{"name":"Pull it through the dies","process":"draw","text":"A rotating drum winds up the wire and drags it through the die. Steel wire uses dies of tungsten carbide. Each pull reduces the area by 15 to 25 percent for small wires and 20 to 45 percent for larger ones.","inputs":[],"spec":"15 to 45% reduction per pull"},{"name":"Anneal between pulls","process":"heat-treat","text":"Drawing hardens the wire. When the total reduction goes past about 50 percent, the wire is annealed to make it soft again so it can be drawn further.","inputs":[]},{"name":"Draw in a continuous train","process":"draw","text":"Production machines run several dies in a row, each with its own drum. Because the wire speeds up after every die, each drum turns faster than the one before. Telephone wire is drawn 20 to 30 times from rod stock.","inputs":[]},{"name":"Final anneal and coil","process":"heat-treat","text":"A last anneal can be given to the finished wire to maximize its ductility. It is then wound into coils or onto spools.","inputs":[]}],"facts":["Very fine wires are drawn in bundles, separated by another metal that is dissolved away afterward.","Dies for the finest wire are cut from a single diamond crystal.","Wire drawing keeps volume constant, so a thinner wire is always a proportionally longer one."],"where":[],"whereNote":null,"sources":[{"title":"Wire drawing","url":"https://en.wikipedia.org/wiki/Wire_drawing"},{"title":"Wire","url":"https://en.wikipedia.org/wiki/Wire"},{"title":"Hot rolling","url":"https://en.wikipedia.org/wiki/Hot_rolling"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sticky-notes","name":"Sticky notes","kind":"product","category":"wood-paper","title":"How sticky notes are made","url":"https://assemblyline.org/make/sticky-notes","stations":7,"upstream":57,"downstream":0,"depth":10,"dek":"The adhesive was a failure. A chemist set out to make super-strong glue and got a weak one that could be used again.","answer":"One patented line unwinds a big roll of paper, loops it through a tension magazine and runs it past a primer applicator and a heater. A flexographic-style applicator lays stripes of repositionable adhesive, and more heat dries them. The web can be printed, then is cut into panels several times the size of one sheet, stacked and trimmed into pads.","aka":["Post-it notes","repositionable notes","sticky pads"],"inputs":["paper","adhesive","ink","cardboard-box"],"uses":[],"grounds":["water","kaolin","limestone","timber","crude-oil","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","natural-gas","coal","sugar-beet"],"upstreamSlugs":["paper","adhesive","ink","cardboard-box","wood-pulp","water","kaolin","limestone","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","cardboard","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","hydrogen","soybeans","rapeseed","hexane","clay","formaldehyde","air","titanium-ore","coke","iron-ore","sulfur","corn","sugarcane","yeast","rock-salt","naphtha","natural-gas","benzene","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Unwind the paper","process":"cut","text":"A large roll feeds the line. The web loops through a magazine of idler rolls and a dancer roll that even out stresses before any coating starts.","inputs":["paper"]},{"name":"Apply and dry primer","process":"coat","text":"An applicator puts a bonding primer on selected parts of one side, and a heater dries it fast. The primer keeps the glue attached to the paper rather than to whatever it sticks to.","inputs":[]},{"name":"Lay adhesive stripes","process":"coat","text":"An applicator resembling a flexographic printer lays lengthwise stripes of a low-viscosity adhesive that can be reactivated by pressure. A second heater dries the stripes.","inputs":["adhesive"]},{"name":"Print the web","process":"print","text":"An optional press adds printed matter on either side, followed by another heater to dry it. Plain notes pass straight through.","inputs":["ink"]},{"name":"Cut into panels","process":"cut","text":"The web is cut across into panels several times the size of one note, so one cut stack will become several pads.","inputs":[]},{"name":"Stack and trim","process":"cut","text":"Panels stack with their glue stripes lined up, so each sheet holds to the next, and trimming cuts the block into finished pads.","inputs":[]},{"name":"Wrap and pack","process":"package","text":"The finished pads are wrapped and boxed for sale.","inputs":["cardboard-box"]}],"facts":["Spencer Silver of 3M was trying to make a super-strong adhesive in 1968 and accidentally invented a reusable low-tack one.","Arthur Fry came up with the idea in 1974, hoping to anchor a bookmark in his hymn book.","The original canary yellow was chosen by chance, because that was the color of the scrap paper in the lab next door."],"where":[],"whereNote":null,"sources":[{"title":"US4743319A: Method of and apparatus for making self sticking note pads","url":"https://patents.google.com/patent/US4743319"},{"title":"Post-it note","url":"https://en.wikipedia.org/wiki/Post-it_note"},{"title":"Paper","url":"https://en.wikipedia.org/wiki/Paper"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"pottery","name":"Stoneware pottery","kind":"product","category":"minerals","title":"How stoneware pottery is made","url":"https://assemblyline.org/make/pottery","stations":7,"upstream":4,"downstream":0,"depth":1,"dek":"Stoneware is fired hot enough that the clay turns waterproof, around 1,100 to 1,300 °C.","answer":"Factory stoneware is mostly formed by machine. Clay is pugged through a vacuum chamber to remove air, cut into blanks and shaped on a jigger, where a spinning mold and a profiled arm make a plate in seconds. Hollow shapes are cast from liquid slip in plaster molds. Pieces are dried, fettled, given a first firing, dipped in glaze and fired again until clay and glaze fuse.","aka":["ceramic pottery","stoneware pot","clay pot"],"inputs":["clay","water","silica-sand","feldspar"],"uses":[],"grounds":["clay","water","silica-sand","feldspar"],"upstreamSlugs":["clay","water","silica-sand","feldspar"],"downstreamSlugs":[],"steps":[{"name":"Pug the clay","process":"knead","text":"Clay runs through a vacuum chamber in a pug mill, which removes air and leaves a uniform body. For casting, dry clay is instead mixed with water into a creamy slip.","inputs":["clay","water"]},{"name":"Jigger the flatware","process":"mold","text":"A cutter stamps round blanks from a slab, and each drops onto a spinning mold. A profiled arm descends and shapes a plate in 2 to 4 seconds.","inputs":[]},{"name":"Cast the hollow shapes","process":"cast","text":"Slip goes into multi-part plaster molds that wick out water, so a solid clay layer builds on the walls. After 45 to 90 minutes the spare slip drains for reuse.","inputs":[]},{"name":"Dry and fettle","process":"dry","text":"Plates ride a controlled dryer for 6 to 12 hours. Seam lines from the mold are then sanded or sponged away by hand or small rotating tool.","inputs":[]},{"name":"Fire the bare clay","process":"fire","text":"A first low firing, the bisque, hardens the ware so it can take glaze without falling apart.","inputs":[]},{"name":"Dip in glaze","process":"coat","text":"Each piece is dipped or sprayed with a liquid mix of silica and feldspar, which dries as a powdery layer on the porous body.","inputs":["silica-sand","feldspar"]},{"name":"Fire it to vitrify","process":"fire","text":"A second, hotter trip through the kiln melts the glaze and turns the clay waterproof.","inputs":[],"spec":"1,100 to 1,300 °C"}],"facts":["Different regions developed stoneware independently, after earthenware and before porcelain.","Dense and impermeable, stoneware is hard enough to resist scratching by a steel point.","Stoneware is usually more opaque than porcelain and only partially vitrified."],"where":[],"whereNote":null,"sources":[{"title":"Tableware.com: Hand-thrown vs slip-cast vs pressed","url":"https://www.tableware.com/posts/wiki/hand-thrown-vs-slip-cast-vs-pressed.html"},{"title":"Stoneware","url":"https://en.wikipedia.org/wiki/Stoneware"},{"title":"Sintering","url":"https://en.wikipedia.org/wiki/Sintering"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"styrene","name":"Styrene","kind":"material","category":"chemicals","title":"How styrene is made","url":"https://assemblyline.org/make/styrene","stations":5,"upstream":9,"downstream":76,"depth":5,"dek":"Left alone, the liquid turns itself into plastic. Plants must keep dosing it to stop that happening inside the pipes.","answer":"Benzene and ethylene join over a zeolite catalyst to make ethylbenzene. Superheated steam and an iron oxide catalyst then pull two hydrogen atoms off, leaving a sweet-smelling oily liquid with a reactive double bond. That bond is what makes it useful, and also why it needs an inhibitor to keep it from turning solid on its way to market.","aka":["styrene monomer","vinylbenzene","phenylethene","styrol"],"inputs":["benzene","ethylene"],"uses":["polystyrene","abs-plastic","synthetic-rubber"],"grounds":["natural-gas","water","crude-oil","coal"],"upstreamSlugs":["benzene","ethylene","naphtha","hydrogen","toluene","natural-gas","water","crude-oil","coal"],"downstreamSlugs":["polystyrene","abs-plastic","synthetic-rubber","surfboard","bike-helmet","ballpoint-pen","polystyrene-foam","foam-cup","smoke-detector","compact-disc","inkjet-printer","lipstick","hearing-aid","thermometer","lego-brick","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","snowboard","action-figure","harmonica","globe","suitcase","high-heels","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","e-reader","graphics-card","remote-control","electric-toothbrush","toothbrush","syringe","rubber","nitrile-glove","chewing-gum","tire","golf-ball","basketball","pencil-eraser","flip-flops","rubber-boots","vacuum-cleaner","electric-kettle","pencil","shipping-container","tennis-ball","baseball","soccer-ball","ski","roller-skates","golf-club","football","volleyball","cricket-bat","dumbbell","treadmill","wheelchair","ladder","wheelbarrow","fire-extinguisher","hiking-boots","loudspeaker","sneaker","leather-shoe","umbrella","car","electric-car","bicycle","motorcycle"],"steps":[{"name":"Join benzene and ethylene","process":"react","text":"The two petrochemicals react over a zeolite catalyst to give ethylbenzene. Older plants used aluminum chloride for this. More than 99% of ethylbenzene goes straight on to the next step.","inputs":["benzene","ethylene"]},{"name":"Strip off two hydrogens","process":"react","text":"Ethylbenzene meets superheated steam over an iron oxide catalyst, and hydrogen comes off. The reaction soaks up heat and can run backward, so yields stop at 88 to 94 percent.","inputs":[]},{"name":"Dose with inhibitor","process":"mix","text":"Heat makes the product link up into polymer on its own. An inhibitor is added continuously during the hot stages so that the columns ahead do not fill with plastic.","inputs":[]},{"name":"Distill through many columns","process":"refine","text":"Crude product and leftover ethylbenzene boil only 9 °C apart, so a whole series of distillation columns is needed to split them. It takes a lot of energy.","inputs":[]},{"name":"Ship before it sets","process":"fill","text":"Treated liquid travels by tanker to plants making polystyrene, ABS and styrene-butadiene rubber. Without the inhibitor it would polymerize in storage.","inputs":[]}],"facts":["The compound was first isolated from storax, a balsam from a flowering shrub, and takes its name from it.","At 100 °C the pure liquid polymerizes itself at about 2% per hour.","World output reached around 35 million tonnes by 2018."],"where":[],"whereNote":null,"sources":[{"title":"Styrene","url":"https://en.wikipedia.org/wiki/Styrene"},{"title":"Ethylbenzene","url":"https://en.wikipedia.org/wiki/Ethylbenzene"},{"title":"Styrene (Britannica)","url":"https://www.britannica.com/science/styrene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"polystyrene-foam","name":"Styrofoam","kind":"material","category":"plastics","title":"How polystyrene foam is made","url":"https://assemblyline.org/make/polystyrene-foam","stations":5,"upstream":12,"downstream":0,"depth":7,"dek":"Foam cups and blue insulation board are the same hard, brittle plastic, puffed full of gas.","answer":"Polystyrene foam starts as solid polystyrene, a plastic that turns runny above about 100 °C. Extruded board is melted, mixed with a gas, and squeezed through a die so it swells as it cools. Molded cups and packing are fused from small pre-expanded beads.","aka":["Styrofoam","expanded polystyrene","EPS","foam"],"inputs":["polystyrene","pentane"],"uses":[],"grounds":["natural-gas","crude-oil","water","coal"],"upstreamSlugs":["polystyrene","pentane","naphtha","ethylene","benzene","styrene","natural-gas","crude-oil","water","hydrogen","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Feed in polystyrene pellets","process":"melt","text":"Solid pellets are melted in a heated barrel. The plastic is glassy at room temperature and flows above its glass transition at about 100 °C.","inputs":["polystyrene"]},{"name":"Mix in a blowing agent","process":"mix","text":"A gas or volatile liquid is blended into the melt under pressure. It will form the bubbles.","inputs":[]},{"name":"Squeeze it through a die","process":"extrude","text":"As the mix exits the die, the pressure drops and the gas expands. The plastic puffs into a closed-cell foam and hardens as it cools.","inputs":[]},{"name":"Cut the board to size","process":"cut","text":"The continuous slab is trimmed and sawn into boards of standard dimensions.","inputs":[]},{"name":"Or expand beads in a mold","process":"mold","text":"For cups and packing, beads that were pre-expanded with a hydrocarbon such as pentane are fed into a mold. Steam fuses them together into one piece.","inputs":["pentane"]}],"facts":["A patent for pre-expanded polystyrene beads was issued to BASF and Fritz Stastny in 1949.","Foam polystyrene is not biodegradable and builds up as litter along shores and waterways.","Styrofoam is a brand name for extruded polystyrene insulation, though many people use it for foam cups."],"where":[],"whereNote":null,"sources":[{"title":"Polystyrene","url":"https://en.wikipedia.org/wiki/Polystyrene"},{"title":"Expanded polystyrene","url":"https://en.wikipedia.org/wiki/Expanded_polystyrene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"subway-train","name":"Subway train","kind":"product","category":"machines","title":"How subway trains are made","url":"https://assemblyline.org/make/subway-train","stations":8,"upstream":85,"downstream":0,"depth":10,"dek":"The first electric rapid transit railway, the City & South London, opened in 1890.","answer":"Steel or aluminum panels are laser cut, formed and welded into a car shell, often by robots, then painted. Bogies, the wheeled chassis under each car, come from a separate shop, where plate is cut, robot-welded and milled. Final assembly bays add seats, wiring and traction motors. Completed cars then face static and rolling tests before they ship.","aka":["metro train","underground train","rapid transit car"],"inputs":["stainless-steel","aluminum","steel","paint","electric-motor"],"uses":[],"grounds":["crude-oil","coal","water","chromite","limestone","air","nickel-ore","bauxite","iron-ore","dolomite","manganese-ore","natural-gas","titanium-ore","sulfur","rock-salt","trona","quartz","timber","zinc-ore","copper-ore","corn","tin-ore","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["stainless-steel","aluminum","steel","paint","electric-motor","steel-scrap","chromium","nickel","oxygen","argon","crude-oil","coal","petroleum-coke","alumina","pig-iron","magnesium","lime","manganese","water","titanium-dioxide","pigment","acrylic","tin-can","sheet-steel","copper-wire","epoxy","ball-bearing","propane","chromite","coke","soda-ash","limestone","air","nickel-ore","sulfuric-acid","bauxite","caustic-soda","iron-ore","dolomite","silicon","manganese-ore","natural-gas","titanium-ore","chlorine","carbon-black","sulfur","propylene","ammonia","methanol","tinplate","lacquer","ink","zinc","copper","phenol","acetone","steel-wire","rock-salt","carbon-dioxide","trona","quartz","charcoal","timber","naphtha","tin","ethanol","vegetable-oil","phenolic-resin","zinc-ore","copper-ore","benzene","corn","yeast","hydrogen","tin-ore","sugarcane","ethylene","soybeans","rapeseed","hexane","clay","formaldehyde","toluene","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut and form panels","process":"cut","inputs":["stainless-steel","aluminum"],"text":"Lasers cut stainless steel or aluminum sheet, and forming machines bend the pieces to shape. One Indian plant gives this work its own hall, along with the welding."},{"name":"Weld the shell","process":"weld","inputs":["steel"],"text":"Robots weld the pieces into a shell held to tight dimensions. A Siemens passenger coach, a cousin of the subway car, took more than 50,000 spot welds across its 85-foot length.","spec":"50,000+ welds on one coach"},{"name":"Paint and finish","process":"coat","inputs":["paint"],"text":"The bare shell moves to a paint and finishing area, where temperature and humidity are controlled, and is prepared for final assembly."},{"name":"Weld bogie frames","process":"weld","inputs":["steel"],"text":"A plate cutter slices steel into shapes and a robot welds them into a frame. At one Australian maker the finished chassis measures about 4m by 3m and half a meter tall."},{"name":"Mill the frames","process":"machine","inputs":[],"text":"A five-axis gantry mill does the final machining and inspection. One shop needs about three months for a batch of 12, enough for one trainset."},{"name":"Add suspension and motors","process":"assemble","inputs":["electric-motor"],"text":"Bogies get their primary and secondary suspension and running gear in an assembly area. Traction motors and converters join the train management system, and the software is tested with the customer's signaling."},{"name":"Fit out the car","process":"assemble","inputs":[],"text":"In final assembly bays, wiring looms, interior fittings and seats go in, and each car comes together with its running gear."},{"name":"Run static, rolling tests","process":"inspect","inputs":[],"text":"Completed cars go through static and rolling checks on dedicated test equipment. A rail siding then carries them out of the plant."}],"facts":["London's partly underground Metropolitan Railway, opened in 1863 with steam locomotives, was the world's first rapid transit system.","Across most of Britain, the word subway means a pedestrian underpass, not a train.","A heavy metro train can run to between six and fourteen cars, with 100 to 150 passengers in each."],"where":[],"whereNote":null,"sources":[{"title":"Metro Rail and EMU Rolling Stock Manufacturing Facility","url":"https://www.imarcengineering.com/case-study/metro-rail-and-emu-rolling-stock-manufacturing-facility"},{"title":"Hofmann Engineering: Gearing up for bogie production","url":"https://amtil.com.au/?p=21554"},{"title":"Siemens completes first car shell for Florida's Brightline rail service","url":"https://www.metro-magazine.com/news/siemens-completes-first-car-shell-for-floridas-brightline-rail-service"},{"title":"Rapid transit","url":"https://en.wikipedia.org/wiki/Rapid_transit"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sugar","name":"Sugar","kind":"product","category":"food","title":"How sugar is made","url":"https://assemblyline.org/make/sugar","stations":8,"upstream":5,"downstream":66,"depth":2,"dek":"White sugar is pure sucrose, squeezed out of cane or beets, clarified with lime and spun in centrifuges.","answer":"Sugar mills crush sugarcane, or wash and slice sugar beets, to get a sugary juice. Lime clarifies the juice, evaporators thicken it into syrup, and seed crystals trigger sugar to crystallize out. Centrifuges spin off the molasses, and a refinery then washes, filters and decolorizes the raw crystals until they are white.","aka":["white sugar","granulated sugar","table sugar","sucrose"],"inputs":["sugarcane","sugar-beet","water","lime"],"uses":["penicillin","insulin","vitamin-c","brown-sugar","yogurt","ice-cream","mayonnaise","ketchup","peanut-butter","croissant","donut","sandwich-cookie","corn-flakes","bacon","chocolate","gummy-bears","marshmallow","jelly-beans","candy-cane","chewing-gum","cotton-candy","sprinkles","cola","champagne","hard-cider","condensed-milk","pickles","kimchi","jam","hazelnut-spread","bagel","imitation-crab","salami","ham","beef-jerky","canned-meat","white-chocolate","caramel-color","candy-coated-chocolate","licorice","caramel","lollipop","toffee","popping-candy","gelatin-dessert","cake-mix","soda","root-beer","energy-drink","kombucha","tonic-water","prosecco","cough-syrup"],"grounds":["sugarcane","sugar-beet","water","limestone"],"upstreamSlugs":["sugarcane","sugar-beet","water","lime","limestone"],"downstreamSlugs":["penicillin","insulin","vitamin-c","brown-sugar","yogurt","ice-cream","mayonnaise","ketchup","peanut-butter","croissant","donut","sandwich-cookie","corn-flakes","bacon","chocolate","gummy-bears","marshmallow","jelly-beans","candy-cane","chewing-gum","cotton-candy","sprinkles","cola","champagne","hard-cider","condensed-milk","pickles","kimchi","jam","hazelnut-spread","bagel","imitation-crab","salami","ham","beef-jerky","canned-meat","white-chocolate","caramel-color","candy-coated-chocolate","licorice","caramel","lollipop","toffee","popping-candy","gelatin-dessert","cake-mix","soda","root-beer","energy-drink","kombucha","tonic-water","prosecco","cough-syrup","flour","rum","bread","instant-noodles","tortilla","pretzel","chicken-nuggets","frozen-pizza","baguette","sourdough","crackers","fish-sticks","modeling-clay"],"steps":[{"name":"Press out the juice","process":"press","text":"Cane is chopped and either milled with water or run through a diffuser to extract the juice. Beets are first washed and sliced into thin strips, and the sugar is soaked out of the strips in the same kind of diffuser. The leftover cane fiber, called bagasse, is burned to power the factory.","inputs":["sugarcane","sugar-beet","water"]},{"name":"Clarify with lime","process":"refine","text":"Lime is added to the raw juice. It neutralizes acids and makes impurities clump together so they can be settled or filtered out. For cane the juice is also heated to destroy enzymes that would break the sugar down.","inputs":["lime"]},{"name":"Boil down to syrup","process":"cook","text":"A chain of evaporators drives off water until the thin juice is a thick syrup. Beet factories boil under a vacuum so the sugar does not scorch at high temperature.","inputs":[]},{"name":"Seed the crystals","process":"grow","text":"Syrup is boiled further until it is supersaturated, then seeded with tiny sugar crystals. Sucrose comes out of solution onto the seeds and the crystals grow in a pan until the mixture is a thick mass of crystals in syrup.","inputs":[]},{"name":"Spin off the molasses","process":"separate","text":"The crystal mass drops into centrifuges that fling the liquid through a fine screen. Beet factories get white sugar from this step. Cane factories get raw sugar with a sticky brown coating, and the liquid that spins off is molasses.","inputs":[]},{"name":"Wash and filter the raw crystals","process":"wash","text":"In a refinery, raw crystals are soaked in concentrated syrup that softens the brown coat without dissolving the sugar. They are spun again, dissolved in water, and treated so a fine solid precipitates in the liquid. Filtering that solid out takes many impurities with it.","inputs":[]},{"name":"Strip out the color","process":"refine","text":"Beds of granular activated carbon or ion-exchange resin hold on to the color compounds that are left as the syrup is pumped through.","inputs":[]},{"name":"Crystallize and dry","process":"dry","text":"The clear syrup is boiled and seeded once more. Spinning off the white crystals, drying them in hot air and packing them follows. What is left over becomes refiners' molasses.","inputs":[]}],"facts":["Beet sugar was first produced industrially in 1801 in Cunern, Prussia.","About 2,500 litres of irrigation water goes into every kilogram of sugar."],"where":[],"whereNote":null,"sources":[{"title":"Sugar","url":"https://en.wikipedia.org/wiki/Sugar"},{"title":"Brown sugar","url":"https://en.wikipedia.org/wiki/Brown_sugar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sugar-beet","name":"Sugar beet","kind":"raw","category":"farm","title":"How sugar beet is grown and harvested","url":"https://assemblyline.org/make/sugar-beet","stations":3,"upstream":0,"downstream":370,"depth":0,"dek":"A sugar beet weighs only half a kilo or so, and in 1747 a Berlin professor found sugar in beetroot.","answer":"Sugar beet is a temperate crop with a fleshy white taproot that stores the sugar made in its leaves. It is planted in spring and lifted from the ground in autumn. Cool nights and long days make sweeter roots, and a machine now does the lifting that once needed a large crew with hoes.","aka":["sugarbeet","beet farming","beet harvest","beetroot for sugar"],"inputs":[],"uses":["sugar","molasses"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["sugar","molasses","penicillin","insulin","vitamin-c","brown-sugar","yogurt","ice-cream","mayonnaise","ketchup","peanut-butter","croissant","donut","sandwich-cookie","corn-flakes","bacon","chocolate","gummy-bears","marshmallow","jelly-beans","candy-cane","chewing-gum","cotton-candy","sprinkles","cola","champagne","hard-cider","condensed-milk","pickles","kimchi","jam","hazelnut-spread","bagel","imitation-crab","salami","ham","beef-jerky","canned-meat","white-chocolate","caramel-color","candy-coated-chocolate","licorice","caramel","lollipop","toffee","popping-candy","gelatin-dessert","cake-mix","soda","root-beer","energy-drink","kombucha","tonic-water","prosecco","cough-syrup","yeast","rum","flour","ethanol","vinegar","bread","pretzel","beer","wine","whiskey","vodka","gin","tequila","sake","frozen-pizza","baguette","crackers","carbon-dioxide","bourbon","scotch","mead","port-wine","light-beer","non-alcoholic-beer","instant-noodles","tortilla","chicken-nuggets","sourdough","fish-sticks","modeling-clay","deodorant","perfume","vaccine","gasoline","ink","vanilla-extract","lacquer","super-glue","insect-repellent","air-freshener","hairspray","mouthwash","mustard","hot-sauce","salsa","aspirin","soda-ash","fertilizer","baking-soda","decaf-coffee","sparkling-water","refrigerant","caffeine","melamine-resin","ethylene-glycol","shampoo","dish-soap","foundation-makeup","car","car-engine","motorcycle","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","guitar","electric-guitar","trumpet","chopsticks","door","chess-set","saxophone","ukulele","felt-hat","baseball-bat","detergent","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","stained-glass","vanadium","fire-extinguisher","refrigerator","air-conditioner","asthma-inhaler","pet-plastic","spandex","locomotive","vacuum-cleaner","electric-kettle","pillow","paint","baby-formula","coconut-milk","canned-soup","electric-car","soap","toothpaste","nitrile-glove","washing-machine","paperclip","popcorn","crayon","fireworks","candle","zip-bag","blender","dishwasher","cotton-swab","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","printed-circuit-board","wind-turbine","surfboard","fishing-rod","kite","roof-shingle","canoe","sailboat","lithium-ion-cell","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather","thermometer","lcd-screen","oled-screen","camera-sensor","solar-panel","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","neon-sign","smartwatch","e-reader","mirror","skyscraper","double-glazed-window","nail-polish","cognac","mezcal","smartphone","polyester","plastic-bottle","3d-printer-filament","drum-kit","bottled-water","leggings","swimsuit","pencil","scissors","airplane","container-ship","shipping-container","bicycle","wooden-chair","water-bottle","ceiling-fan","tennis-racket","golf-club","billiard-ball","dartboard","dice","action-figure","fashion-doll","toy-car","coil-spring","hammer","gas-cylinder","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","hearing-aid","pacemaker","led-bulb","ev-battery","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","airbag","rocket","elevator","treadmill","pinball-machine","phone-charger","digital-camera","graphics-card","electric-toothbrush","kitchen-knife","fork","fountain-pen","thermos","pressure-cooker","jet-engine","football","winter-gloves","handbag","wallet","hiking-boots","high-heels","leather-shoe","sauerkraut","tire","sofa","office-chair","garden-hose","volleyball","kitchen-sponge","wet-wipes","seat-belt","hoodie","raincoat","backpack","suitcase","shoelace","curtain","microphone","sneaker","mattress","zipper","button","thread","teddy-bear","sunscreen","bleach","hair-dye","padlock","down-jacket","jeans","dress-shirt","suit","baseball-cap","bike-helmet","yo-yo","tampon","silk-tie","blanket","socks","sweater","towel"],"steps":[{"name":"Sow in rich, level soil","process":"grow","text":"Sugar beet wants deep, well-drained soil full of nutrients and humus, ideally a sandy loam. It needs to be cultivated 30 to 38 cm deep, and without irrigation it needs around 460 mm of rain.","inputs":[]},{"name":"Thin and weed","process":"grow","text":"Until the second half of the twentieth century, farmers planted densely to control weeds and then thinned the plants by hoe two or three times a season. The work was highly labor-intensive.","inputs":[]},{"name":"Lift the roots","process":"harvest","text":"In most temperate climates beets go in during spring and come out in autumn. A plow-like device used to lift them behind a team of horses. Machines now do the lifting and the rest of the preparation that once took many hands.","inputs":[]}],"facts":["In 1747 Andreas Sigismund Marggraf isolated sugar from beetroots and found it at concentrations of 1.3 to 1.6%.","Sugar beets are grown in climates too cold for sugarcane.","Modern sugar beets date to the mid-18th century in Silesia, where Frederick the Great subsidized experiments in sugar extraction."],"where":[{"place":"Russia","share":"largest producer"},{"place":"Germany","share":"second largest producer"}],"whereNote":"2024, ranking by sugar beet production; the world total was 294 million tonnes.","sources":[{"title":"Sugar beet","url":"https://en.wikipedia.org/wiki/Sugar_beet"},{"title":"Sugar","url":"https://en.wikipedia.org/wiki/Sugar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sugarcane","name":"Sugarcane","kind":"raw","category":"farm","title":"How sugarcane is grown and harvested","url":"https://assemblyline.org/make/sugarcane","stations":4,"upstream":0,"downstream":370,"depth":0,"dek":"Sugarcane is the world's biggest crop by weight, and cutters traditionally burn the field first to chase out snakes.","answer":"Sugarcane is a tall tropical grass planted from stalk cuttings, each with at least one bud. It needs warmth and plentiful water for more than 6 to 7 months a year. Cane is cut at ground level, either by hand with knives after the field has been burned, or by a harvester that strips and chops the stalks.","aka":["sugar cane","cane farming","cane harvest","sugar cane crop"],"inputs":[],"uses":["ethanol","sugar","rum","molasses"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["ethanol","sugar","rum","molasses","deodorant","perfume","vaccine","gasoline","ink","vanilla-extract","vinegar","gin","lacquer","super-glue","port-wine","insect-repellent","air-freshener","hairspray","mouthwash","penicillin","insulin","vitamin-c","brown-sugar","yogurt","ice-cream","mayonnaise","ketchup","peanut-butter","croissant","donut","sandwich-cookie","corn-flakes","bacon","chocolate","gummy-bears","marshmallow","jelly-beans","candy-cane","chewing-gum","cotton-candy","sprinkles","cola","champagne","hard-cider","condensed-milk","pickles","kimchi","jam","hazelnut-spread","bagel","imitation-crab","salami","ham","beef-jerky","canned-meat","white-chocolate","caramel-color","candy-coated-chocolate","licorice","caramel","lollipop","toffee","popping-candy","gelatin-dessert","cake-mix","soda","root-beer","energy-drink","kombucha","tonic-water","prosecco","cough-syrup","yeast","shampoo","dish-soap","foundation-makeup","car","car-engine","motorcycle","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","mustard","hot-sauce","salsa","guitar","electric-guitar","trumpet","chopsticks","door","chess-set","saxophone","ukulele","felt-hat","baseball-bat","flour","bread","pretzel","beer","wine","whiskey","vodka","tequila","sake","frozen-pizza","baguette","crackers","carbon-dioxide","bourbon","scotch","mead","light-beer","non-alcoholic-beer","locomotive","vacuum-cleaner","electric-kettle","pillow","paint","baby-formula","coconut-milk","canned-soup","sparkling-water","electric-car","soap","toothpaste","detergent","nitrile-glove","washing-machine","paperclip","popcorn","crayon","fireworks","candle","fish-sticks","zip-bag","blender","dishwasher","cotton-swab","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","instant-noodles","tortilla","chicken-nuggets","sourdough","modeling-clay","aspirin","soda-ash","fertilizer","baking-soda","decaf-coffee","refrigerant","caffeine","melamine-resin","ethylene-glycol","refrigerator","microwave-oven","pencil","scissors","mirror","airplane","container-ship","shipping-container","bicycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","stained-glass","vanadium","air-conditioner","asthma-inhaler","pet-plastic","spandex","padlock","printed-circuit-board","wind-turbine","surfboard","kite","roof-shingle","canoe","sailboat","lithium-ion-cell","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather","thermometer","lcd-screen","oled-screen","camera-sensor","solar-panel","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","smartwatch","e-reader","skyscraper","double-glazed-window","nail-polish","cognac","mezcal","smartphone","polyester","plastic-bottle","3d-printer-filament","drum-kit","bottled-water","leggings","swimsuit","hearing-aid","pacemaker","led-bulb","ev-battery","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","airbag","rocket","elevator","treadmill","pinball-machine","phone-charger","digital-camera","graphics-card","electric-toothbrush","kitchen-knife","fork","fountain-pen","thermos","pressure-cooker","jet-engine","football","winter-gloves","handbag","wallet","hiking-boots","high-heels","leather-shoe","sauerkraut","tire","sofa","office-chair","garden-hose","volleyball","kitchen-sponge","wet-wipes","seat-belt","hoodie","raincoat","backpack","suitcase","shoelace","curtain","microphone","sneaker","mattress","zipper","button","thread","teddy-bear","sunscreen","bleach","hair-dye","down-jacket","jeans","dress-shirt","suit","baseball-cap","bike-helmet","yo-yo","tampon","silk-tie","blanket","socks","sweater","towel"],"steps":[{"name":"Plant stalk cuttings","process":"grow","text":"Modern cane is propagated from stem cuttings rather than seed, and each piece must carry at least one bud. In places like the United States and Australia machines plant billets, which are stalk sections, into opened furrows.","inputs":[]},{"name":"Grow in warm, wet land","process":"grow","text":"Stalks reach 2 to 7 m tall, so the crop needs a tropical or subtropical climate and a minimum of 60 cm of moisture a year. It does not tolerate severe frost, so most of it is grown between 22°N and 22°S.","inputs":[],"spec":"at least 60 cm of moisture a year"},{"name":"Burn, then cut the cane","process":"harvest","text":"In hand harvesting the field is set on fire first, which burns off dry leaves and drives out snakes without damaging the stalks. Cutters then chop the cane just above ground with knives or machetes. A skilled one cuts 500 kg an hour.","inputs":[],"spec":"500 kg per hour by hand"},{"name":"Chop with a harvester","process":"harvest","text":"A mechanical harvester cuts the cane at the base, strips the leaves, chops the stalks to consistent lengths and drops them into a trailing transporter. One machine can handle 100 long tons an hour.","inputs":[]}],"facts":["Sugarcane is the world's largest crop by production quantity and supplies 79% of the sugar produced globally.","Hand harvesting accounts for more than half of production and dominates in the developing world."],"where":[{"place":"Brazil","share":"40% of world output"}],"whereNote":"2020, share of the 1.9 billion tonnes of sugarcane produced worldwide.","sources":[{"title":"Sugarcane","url":"https://en.wikipedia.org/wiki/Sugarcane"},{"title":"Sugar","url":"https://en.wikipedia.org/wiki/Sugar"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sulfur","name":"Sulfur","kind":"raw","category":"ground","title":"How sulfur is recovered","url":"https://assemblyline.org/make/sulfur","stations":4,"upstream":0,"downstream":411,"depth":0,"dek":"Most of the world's sulfur is now a by-product of cleaning up oil and gas, and it piles up in yellow stockpiles.","answer":"Sulfur is recovered in two main ways. Petroleum and natural gas, the main industrial sources, are stripped of sulfur compounds to meet fuel standards. Deep native deposits can be melted in place by pumping superheated water down a well, the Frasch process, and the liquid sulfur is brought up to cool into yellow solid.","aka":["brimstone","elemental sulfur"],"inputs":[],"uses":["sulfuric-acid","rubber","balloon","nitrile-glove","tire","hockey-puck","fireworks","rubber-band","pencil-eraser","rubber-boots","pigment","match"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["sulfuric-acid","rubber","balloon","nitrile-glove","tire","hockey-puck","fireworks","rubber-band","pencil-eraser","rubber-boots","pigment","match","shampoo","nail-polish","aspirin","detergent","fertilizer","chlorine","acrylic","ptfe","kevlar","titanium-dioxide","lithium-carbonate","copper","zinc","nickel","silver","cobalt","manganese","phosphoric-acid","refrigerant","indium","germanium","car-battery","vanadium","rayon","computer-keyboard","vacuum-cleaner","electric-kettle","pencil","shipping-container","tennis-ball","baseball","soccer-ball","ski","snowboard","roller-skates","golf-club","football","volleyball","cricket-bat","dumbbell","treadmill","wheelchair","ladder","wheelbarrow","fire-extinguisher","hiking-boots","high-heels","loudspeaker","inkjet-printer","electric-toothbrush","sneaker","leather-shoe","umbrella","car","electric-car","bicycle","motorcycle","toothbrush","lipstick","mascara","pvc","abs-plastic","ink","paint","lego-brick","lcd-screen","porcelain","chalk","candy-cane","sprinkles","crayon","plastic-straw","printer-toner","billiard-ball","foundation-makeup","eyeshadow","eyeglass-frame","towel","bleach","polycarbonate","epoxy","polyurethane","titanium","gold","hydrochloric-acid","spandex","iridium","adhesive","sunglasses","lacquer","globe","razor-blade","nonstick-pan","raincoat","brake-pad","canoe","toothpaste","sunscreen","candy-coated-chocolate","pvc-pipe","e-reader","lithium-ion-cell","hearing-aid","thermometer","microchip","memory-chip","printed-circuit-board","ev-battery","camera-sensor","solar-panel","refrigerator","microwave-oven","copper-wire","brass","bronze","solder","faucet","padlock","coin","gold-ring","rocket","air-conditioner","flute","toy-car","medal","bell","stained-glass","light-switch","power-outlet","spark-plug","game-console","wifi-router","graphics-card","jeans","aa-battery","sheet-steel","rebar","lead","neodymium-magnet","nail","screw","steel-pipe","zinc-oxide","staple","bolt","barbed-wire","chain-link-fence","suspension-bridge-cable","stainless-steel","safety-pin","needle","jet-engine","turbine-blade","trumpet","toaster","key","wrench","usb-cable","vinyl-record","compact-disc","nichrome","solar-cell","mirror","thermos","saxophone","smoke-detector","hip-implant","hard-drive","tungsten-carbide","stent","steel","cola","soda","asthma-inhaler","led","indium-tin-oxide","optical-fiber","tampon","laptop","credit-card","plastic-wrap","dishwasher","garden-hose","yoga-mat","action-figure","fashion-doll","inflatable-pool-toy","vinyl-floor","power-cable","flip-flops","3d-printer-filament","television","computer-mouse","headphones","rubiks-cube","ballpoint-pen","harmonica","suitcase","wireless-earbuds","phone-charger","remote-control","syringe","plastic-bag","tin-can","aluminum-can","windshield","skateboard","golf-ball","basketball","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","frisbee","board-game","jigsaw-puzzle","trading-cards","floor-tile","underwear","flag","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","washing-machine","scissors","airplane","container-ship","locomotive","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","fishing-rod","bowling-ball","dartboard","dice","snow-globe","coil-spring","hammer","gas-cylinder","neon-sign","aluminum-window-frame","subway-train","leather-belt","smartwatch","digital-camera","donut","kitchen-sponge","led-bulb","drone","eyeglass-lens","bike-helmet","blender","camera-lens","wind-turbine","electric-motor","surfboard","prosthetic-leg","adhesive-bandage","pacemaker","hardwood-floor","sofa","office-chair","leggings","swimsuit","backpack","mattress","drill-bit","fountain-pen","gold-bar","deodorant","silicone","polysilicon","platinum","trichlorosilane","duct-tape","insulation","popcorn","guitar","piano","violin","drum-kit","paper-straw","paper-bag","door","clear-tape","ice-skates","chess-set","kite","ukulele","cello","drumstick","pinball-machine","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","sailboat","dress-shirt","suit","handbag","wallet","microphone","plywood","mdf","cardboard","toilet-paper","envelope","baseball-cap","carpet","diaper","electric-guitar","chopsticks","felt-hat","baseball-bat","smartphone","satellite","solid-state-drive","airbag","elevator","transformer","wristwatch","guitar-string","hinge","zipper","bronze-statue","ball-bearing","saw-blade","shovel","concrete","skyscraper","ferrite","kitchen-knife","fork","pressure-cooker","tinplate","steel-wire","steel-beam","rail","car-engine","wine-barrel","yo-yo","dental-floss","seat-belt","oled-screen","cotton-candy","pillow","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","sparkling-water","beer","hard-cider","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","soap","paperclip","corn-flakes","candle","salsa","fish-sticks","zip-bag","mouthwash","cough-syrup","facial-tissue","condom","contact-lens","cork-stopper","silicon-wafer","cake-mix","hair-dye","down-jacket","canned-tuna","air-freshener","hairspray","wire-rope","clothespin","slinky","chain","wine","bourbon","scotch","cognac","port-wine","toffee","champagne"],"steps":[{"name":"Strip it from oil and gas","process":"refine","text":"Petroleum and natural gas carry sulfur compounds that must be removed before the fuel is used. The sulfur taken out is sold on, and since the late twentieth century this has been the main route.","inputs":[]},{"name":"Melt it underground","process":"drill","text":"In the Frasch process, three concentric pipes go down into a sulfur deposit. Superheated water at 165 °C goes down the outer pipe, melting the sulfur, which has a melting point of 115 °C.","inputs":[],"spec":"165 °C water"},{"name":"Lift the liquid sulfur","process":"drill","text":"Compressed air in the inner pipe lifts the molten sulfur to the surface, where it is poured into tanks or vats to harden. The product is about 99.5% pure sulfur, light yellow.","inputs":[]},{"name":"Mine the volcanic crust","process":"mine","text":"Native sulfur is also found near hot springs and volcanic regions, along the Pacific Ring of Fire. Such volcanic deposits are mined in Indonesia, Chile and Japan.","inputs":[]}],"facts":["In 1894 the chemist Herman Frasch devised his method to get sulfur out from under a layer of quicksand in Louisiana.","The Frasch process can produce sulfur about 99.5% pure.","Stockpiles of elemental sulfur from refining oil sands exist throughout Alberta, Canada."],"where":[],"whereNote":null,"sources":[{"title":"Sulfur","url":"https://en.wikipedia.org/wiki/Sulfur"},{"title":"Frasch process","url":"https://en.wikipedia.org/wiki/Frasch_process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sulfuric-acid","name":"Sulfuric acid","kind":"material","category":"chemicals","title":"How sulfuric acid is made","url":"https://assemblyline.org/make/sulfuric-acid","stations":6,"upstream":3,"downstream":404,"depth":1,"dek":"The world's most-used industrial acid is made by burning sulfur and passing the smoke over a catalyst.","answer":"Sulfuric acid is made by burning molten sulfur in dry air to form sulfur dioxide gas, then passing the cleaned gas over a vanadium catalyst so it picks up more oxygen. The resulting sulfur trioxide is absorbed into strong acid, and water is added to bring the acid to the grade a customer wants.","aka":["oil of vitriol","battery acid","H2SO4","contact process"],"inputs":["sulfur","air","water"],"uses":["shampoo","nail-polish","aspirin","detergent","fertilizer","chlorine","acrylic","ptfe","kevlar","titanium-dioxide","lithium-carbonate","copper","zinc","nickel","silver","cobalt","manganese","phosphoric-acid","refrigerant","indium","germanium","car-battery","vanadium","rayon"],"grounds":["sulfur","air","water"],"upstreamSlugs":["sulfur","air","water"],"downstreamSlugs":["shampoo","nail-polish","aspirin","detergent","fertilizer","chlorine","acrylic","ptfe","kevlar","titanium-dioxide","lithium-carbonate","copper","zinc","nickel","silver","cobalt","manganese","phosphoric-acid","refrigerant","indium","germanium","car-battery","vanadium","rayon","bleach","pvc","polycarbonate","epoxy","polyurethane","nitrile-glove","titanium","gold","hydrochloric-acid","spandex","iridium","paint","adhesive","lcd-screen","sunglasses","lacquer","globe","razor-blade","nonstick-pan","raincoat","brake-pad","canoe","toothpaste","sunscreen","lipstick","ink","crayon","pencil-eraser","candy-coated-chocolate","foundation-makeup","pvc-pipe","e-reader","pigment","lithium-ion-cell","hearing-aid","thermometer","microchip","memory-chip","printed-circuit-board","ev-battery","camera-sensor","solar-panel","refrigerator","microwave-oven","copper-wire","brass","bronze","solder","faucet","padlock","coin","gold-ring","rocket","air-conditioner","flute","toy-car","medal","bell","stained-glass","light-switch","power-outlet","spark-plug","game-console","wifi-router","graphics-card","jeans","aa-battery","sheet-steel","rebar","lead","neodymium-magnet","nail","screw","steel-pipe","zinc-oxide","staple","bolt","barbed-wire","chain-link-fence","suspension-bridge-cable","stainless-steel","safety-pin","needle","jet-engine","turbine-blade","trumpet","toaster","key","wrench","eyeglass-frame","usb-cable","vinyl-record","compact-disc","nichrome","solar-cell","mirror","thermos","saxophone","smoke-detector","hip-implant","hard-drive","tungsten-carbide","stent","steel","cola","soda","asthma-inhaler","led","indium-tin-oxide","optical-fiber","tampon","kitchen-sponge","credit-card","plastic-wrap","dishwasher","garden-hose","football","volleyball","yoga-mat","action-figure","fashion-doll","inflatable-pool-toy","vinyl-floor","power-cable","flip-flops","led-bulb","drone","eyeglass-lens","bike-helmet","blender","suitcase","smartwatch","wireless-earbuds","phone-charger","digital-camera","camera-lens","wind-turbine","electric-motor","aluminum-can","airplane","surfboard","ski","snowboard","tennis-racket","fishing-rod","prosthetic-leg","loudspeaker","umbrella","adhesive-bandage","pacemaker","car","skateboard","golf-ball","soccer-ball","hardwood-floor","water-heater","sofa","office-chair","roller-skates","bowling-ball","wheelchair","underwear","leggings","swimsuit","backpack","sneaker","mattress","drill-bit","fountain-pen","gold-bar","deodorant","silicone","polysilicon","platinum","trichlorosilane","washing-machine","electric-kettle","pencil","scissors","electric-car","container-ship","shipping-container","locomotive","bicycle","motorcycle","wallpaper","wooden-chair","water-bottle","ceiling-fan","golf-club","billiard-ball","dartboard","dice","snow-globe","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","aluminum-window-frame","subway-train","leather-belt","duct-tape","insulation","popcorn","windshield","guitar","piano","violin","drum-kit","tennis-ball","baseball","basketball","paper-straw","paper-bag","pizza-box","laminate-floor","door","clear-tape","ice-skates","cricket-bat","chess-set","kite","board-game","jigsaw-puzzle","ukulele","cello","drumstick","pinball-machine","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","sailboat","dress-shirt","suit","handbag","wallet","hiking-boots","high-heels","microphone","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","leather-shoe","baseball-cap","carpet","diaper","laptop","television","tin-can","electric-guitar","chopsticks","felt-hat","baseball-bat","syringe","plastic-bag","rubiks-cube","ballpoint-pen","paper-cup","marker-pen","highlighter","frisbee","trading-cards","floor-tile","flag","inkjet-printer","newspaper","banknote","t-shirt","toothbrush","mascara","abs-plastic","lego-brick","porcelain","chalk","candy-cane","sprinkles","plastic-straw","printer-toner","eyeshadow","towel","smartphone","satellite","electric-toothbrush","solid-state-drive","computer-keyboard","computer-mouse","airbag","remote-control","elevator","treadmill","headphones","transformer","vacuum-cleaner","wristwatch","tire","harmonica","guitar-string","hinge","zipper","bronze-statue","ball-bearing","saw-blade","shovel","concrete","skyscraper","ferrite","kitchen-knife","fork","pressure-cooker","tinplate","steel-wire","steel-beam","rail","car-engine","wine-barrel","dumbbell","yo-yo","dental-floss","seat-belt","oled-screen","sparkling-water","beer","hard-cider","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","condom","contact-lens","cork-stopper","silicon-wafer","fireworks","cake-mix","hair-dye","soap","paperclip","donut","corn-flakes","cotton-candy","candle","salsa","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","cough-syrup","facial-tissue","condensed-milk","baby-formula","coconut-milk","canned-soup","3d-printer-filament","down-jacket","canned-tuna","air-freshener","hairspray","wire-rope","clothespin","slinky","chain","wine","bourbon","scotch","cognac","port-wine","champagne","toffee"],"steps":[{"name":"Melt and spray the sulfur","process":"melt","text":"Solid sulfur is melted, filtered to remove grit, and sprayed into a furnace as fine droplets. Spraying gives the liquid a huge surface so that it burns quickly.","inputs":["sulfur"]},{"name":"Burn it in dried air","process":"react","text":"Sulfur burns in a blast of air that has been dried first, producing sulfur dioxide gas and a lot of heat. Waste-heat boilers capture that heat as steam.","inputs":["air"]},{"name":"Clean and dry the gas","process":"wash","text":"Dust and moisture are stripped from the gas, and the gas is dried by sulfuric acid itself. Impurities would foul the catalyst and wreck the next step.","inputs":[]},{"name":"Pass it over the catalyst","process":"react","text":"Inside a tall converter the gas flows through several beds of a vanadium oxide catalyst, which helps it pick up one more oxygen atom and become sulfur trioxide. The gas is cooled between beds.","inputs":[]},{"name":"Absorb it in strong acid","process":"react","text":"Dropped into water, sulfur trioxide would make a hot acid mist, so it is fed into concentrated acid in an absorption tower, where it forms a fuming liquid called oleum.","inputs":[]},{"name":"Dilute to the right grade","process":"mix","text":"Water is added in controlled amounts to bring the acid to the strength a customer ordered. Plants that run the gas through the converter and absorber twice convert nearly all of it.","inputs":["water"]}],"facts":["Sulfuric acid dehydrates sugar and paper so aggressively that it pulls the water out of their molecules and leaves black carbon.","Sulfuric acid's biggest customer is fertilizer manufacture, and it is also used in mineral processing, oil refining and lead-acid batteries.","The contact process was patented in 1831 by a British vinegar merchant, and it replaced the lead chamber process."],"where":[],"whereNote":null,"sources":[{"title":"Sulfuric acid","url":"https://en.wikipedia.org/wiki/Sulfuric_acid"},{"title":"Contact process","url":"https://en.wikipedia.org/wiki/Contact_process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sunglasses","name":"Sunglasses","kind":"product","category":"minerals","title":"How sunglasses are made","url":"https://assemblyline.org/make/sunglasses","stations":9,"upstream":43,"downstream":0,"depth":7,"dek":"How dark a lens looks tells you nothing about how much ultraviolet light it blocks.","answer":"Good acetate frames start as thick sheets sawn into strips and milled on a CNC machine, in up to 30 stages. The rough parts tumble for 4 days in drums of beech pegs and paste, then get ultrasonic cleaning and hand polishing with wax. Hinges are riveted on, the mating angles are cut and the temples are heated and bent. Molded and tinted lenses are fitted last, and their ultraviolet protection is measured.","aka":["shades","sun glasses","polarized sunglasses"],"inputs":["cellulose-acetate","water","nickel","polycarbonate","acrylic","glass"],"uses":[],"grounds":["water","nickel-ore","silica-sand","limestone","timber","air","sulfur","crude-oil","rock-salt","natural-gas","trona","corn","coal","sugarcane","sugar-beet"],"upstreamSlugs":["cellulose-acetate","water","nickel","polycarbonate","acrylic","glass","wood-pulp","acetic-anhydride","acetone","plasticizer","nickel-ore","sulfuric-acid","phenol","propylene","caustic-soda","chlorine","ammonia","methanol","silica-sand","soda-ash","limestone","timber","lime","oxygen","hydrogen-peroxide","carbon-monoxide","benzene","air","naphtha","sulfur","crude-oil","rock-salt","natural-gas","carbon-dioxide","trona","hydrogen","toluene","corn","yeast","coal","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Saw the acetate sheets","process":"cut","text":"Sheets of cellulose acetate, 8mm thick for fronts and 6mm for temples, go through a circular table saw into strips that fit the milling machine.","inputs":["cellulose-acetate"]},{"name":"Mill fronts and temples","process":"machine","text":"A CNC mill cuts the shapes using various tools, with as many as 30 machining stages on a front. Parts come off sharp and full of cutting marks.","inputs":[]},{"name":"Tumble in beech pegs","process":"grind","text":"Parts seal into octagonal wooden drums with small beech pegs, oil and paste. Four stages of finer media run 24 hours each, for 4 consecutive days.","inputs":[]},{"name":"Clean ultrasonically","process":"wash","text":"Sorted by hand out of the pegs, the parts go in an ultrasonic bath, where sound waves blast grit out of the smallest holes.","inputs":["water"]},{"name":"Hand polish with wax","process":"grind","text":"Workers press each part to spinning mops with 4 grades of wax compound, each finer than the last. Too much pressure burns the acetate.","inputs":[]},{"name":"Rivet on the hinges","process":"assemble","text":"A drill press makes fresh holes, and hinges are fastened by hand with solid nickel rivets through the frame fronts and temples.","inputs":["nickel"]},{"name":"Cut and bend to fit","process":"press","text":"A slim rotating blade cuts the mitre angle that sets how far temples open. A rotary heater then softens the temples, and pneumatic jaws press in six curvatures.","inputs":[]},{"name":"Form and tint lenses","process":"mold","text":"Lenses are molded from glass or plastic and tinted, and some receive a polarizing layer or a mirror coating.","inputs":["polycarbonate","acrylic","glass"]},{"name":"Fit and measure","process":"inspect","text":"Lenses go into the frame grooves, and the finished pair's ultraviolet block is measured against the standard.","inputs":[]}],"facts":["Sam Foster produced the first inexpensive mass-market sunglasses from celluloid in 1929.","Crookes lenses, introduced in 1913, used glass containing cerium to block ultraviolet light completely.","As of 2008, Xiamen, China, was the world's largest producer of sunglasses, exporting 120 million pairs each year."],"where":[],"whereNote":null,"sources":[{"title":"Banton Frameworks: How are sunglasses made?","url":"https://www.bantonframeworks.co.uk/blogs/manufacture/how-are-sunglasses-made"},{"title":"Sunglasses","url":"https://en.wikipedia.org/wiki/Sunglasses"},{"title":"Corrective lens","url":"https://en.wikipedia.org/wiki/Corrective_lens"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sunscreen","name":"Sunscreen","kind":"product","category":"body-health","title":"How sunscreen is made","url":"https://assemblyline.org/make/sunscreen","stations":8,"upstream":40,"downstream":0,"depth":7,"dek":"Mineral sunscreen is basically ground-up zinc oxide or titanium dioxide, whipped into lotion.","answer":"Sunscreen is an emulsion of oil and water that carries UV-blocking ingredients. These are either powdered minerals such as zinc oxide and titanium dioxide, or organic chemicals that absorb ultraviolet light. Oil and water phases are heated separately, combined with high-shear mixing, cooled, tested and filled into tubes or bottles.","aka":["sunblock","suntan lotion","SPF lotion"],"inputs":["zinc","titanium-dioxide","crude-oil","vegetable-oil","paraffin-wax","water","glycerin","plastic-bottle"],"uses":[],"grounds":["crude-oil","water","zinc-ore","air","titanium-ore","soybeans","rapeseed","clay","sulfur","rock-salt","coal","natural-gas","oil-palm-fruit","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["zinc","titanium-dioxide","crude-oil","vegetable-oil","paraffin-wax","water","glycerin","plastic-bottle","zinc-ore","air","sulfuric-acid","titanium-ore","chlorine","coke","oxygen","soybeans","rapeseed","hexane","clay","hydrogen","palm-oil","caustic-soda","methanol","pet-plastic","sulfur","rock-salt","coal","natural-gas","oil-palm-fruit","p-xylene","ethylene","ethylene-glycol","naphtha","carbon-dioxide","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mill the mineral powders","process":"grind","text":"Zinc oxide and titanium dioxide are ground into particles small enough to spread evenly on skin. Many are coated so they do not clump in the oil.","inputs":["zinc","titanium-dioxide"]},{"name":"Make organic filters","process":"react","text":"Chemical sunscreens use petroleum-based molecules that absorb ultraviolet light and release it as a little heat. They are synthesized in a chemical plant and arrive as powders or oils.","inputs":["crude-oil"]},{"name":"Heat the oil phase","process":"melt","text":"Oils, waxes and the UV filters are warmed together in one stainless vessel until everything is liquid and uniform.","inputs":["vegetable-oil","paraffin-wax"]},{"name":"Heat the water phase","process":"mix","text":"In a second vessel, water, glycerin and thickeners are brought to the same temperature as the oil phase.","inputs":["water","glycerin"]},{"name":"Emulsify the two","process":"mix","text":"The phases are combined under a high-speed mixer that breaks the oil into droplets so tiny they stay suspended. The result is a smooth white lotion.","inputs":[]},{"name":"Cool and add the delicate bits","process":"chill","text":"As the batch cools, preservatives, fragrance and heat-sensitive ingredients are stirred in.","inputs":[]},{"name":"Test the protection","process":"inspect","text":"The sun protection factor is measured by exposing lab test subjects or instruments to UV light. Batches are also checked for texture and stability.","inputs":[]},{"name":"Fill and seal","process":"fill","text":"Tubes and bottles are filled, sealed and labeled with the protection rating.","inputs":["plastic-bottle"]}],"facts":["Austrian chemist Franz Greiter developed a glacier cream in 1946 that became the basis for the Piz Buin brand, named after the mountain where he allegedly got sunburned.","Mineral sunscreens work mostly by absorbing UV light, with some of it also reflected and scattered."],"where":[],"whereNote":null,"sources":[{"title":"Sunscreen","url":"https://en.wikipedia.org/wiki/Sunscreen"},{"title":"Zinc oxide","url":"https://en.wikipedia.org/wiki/Zinc_oxide"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"super-glue","name":"Super glue","kind":"product","category":"chemicals","title":"How super glue is made","url":"https://assemblyline.org/make/super-glue","stations":6,"upstream":15,"downstream":0,"depth":5,"dek":"Super glue sets because moisture in the air, even on a dry-looking surface, triggers it.","answer":"Chemical plants make a cyanoacetate ester from ethanol and react it with formaldehyde to form a rubbery polymer. Heating that polymer under vacuum cracks it back into liquid monomer, which is distilled and stabilized. Water on the surfaces being glued later sets it off, and it hardens in seconds.","aka":["cyanoacrylate","instant glue","crazy glue"],"inputs":["ethanol","formaldehyde"],"uses":[],"grounds":["corn","sugarcane","water","air","natural-gas","sugar-beet","crude-oil"],"upstreamSlugs":["ethanol","formaldehyde","corn","sugarcane","water","yeast","ethylene","methanol","air","molasses","naphtha","natural-gas","sugar-beet","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Make the ester","process":"react","text":"Most super glue is ethyl cyanoacrylate. Its ethyl group comes from ethanol, which is joined to cyanoacetic acid to make the starting ester.","inputs":["ethanol"]},{"name":"React with formaldehyde","process":"react","text":"The ester reacts with formaldehyde. Water is given off, and a solid polymer forms.","inputs":["formaldehyde"]},{"name":"Crack the polymer","process":"react","text":"The polymer is heated under reduced pressure so it breaks back down into monomer, a liquid that boils off. A dark residue builds up on reactor walls, which makes cleaning a problem for plants.","inputs":[]},{"name":"Purify the monomer","process":"refine","text":"The monomer is condensed and distilled to remove impurities. Pure monomer is very prone to setting by itself.","inputs":[]},{"name":"Add stabilizers","process":"mix","text":"Small amounts of stabilizers keep the liquid from polymerizing in the bottle. Fumed silica may be added to make a gel that does not run.","inputs":[]},{"name":"Fill sealed tubes","process":"fill","text":"Glue goes into small tubes sealed against moisture. Once opened, shelf life is about a month, and a refrigerator can extend it.","inputs":[]}],"facts":["The glue cures when hydroxide ions in water set off a chain reaction that links molecules into long, strong chains.","Unopened super glue lasts about a year, but only about a month once opened.","Fumes from warmed cyanoacrylate react with fingerprint residue on glass and plastic, leaving white ridges that forensic investigators can photograph."],"where":[],"whereNote":null,"sources":[{"title":"Cyanoacrylate","url":"https://en.wikipedia.org/wiki/Cyanoacrylate"},{"title":"Process for the manufacture of methyl cyanoacrylate","url":"https://patents.google.com/patent/US5455369"},{"title":"Ethyl cyanoacetate","url":"https://en.wikipedia.org/wiki/Ethyl_cyanoacetate"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"superabsorbent-polymer","name":"Superabsorbent polymer","kind":"material","category":"plastics","title":"How superabsorbent polymer is made","url":"https://assemblyline.org/make/superabsorbent-polymer","stations":6,"upstream":10,"downstream":2,"depth":5,"dek":"A pinch of this powder can hold hundreds of times its own weight in water, which is why diapers work.","answer":"Superabsorbent polymer starts as acrylic acid partly neutralized with sodium hydroxide in water, plus a cross-linker that stops the chains from dissolving. Once polymerized it sets into a wet gel, which gets chopped, dried, ground and sieved. A last round of cross-linking at each grain's surface finishes the powder, which can absorb 300 times its weight in pure water.","aka":["SAP","sodium polyacrylate","water-lock powder"],"inputs":["acrylic-acid","caustic-soda"],"uses":["sanitary-pad","diaper"],"grounds":["air","rock-salt","water","crude-oil","natural-gas"],"upstreamSlugs":["acrylic-acid","caustic-soda","propylene","air","rock-salt","water","naphtha","crude-oil","hydrogen","natural-gas"],"downstreamSlugs":["sanitary-pad","diaper"],"steps":[{"name":"Neutralize the monomers","process":"mix","text":"Acrylic acid is blended with sodium hydroxide in water, so that part of its acid groups become sodium salt. A cross-linker joins the mix. One patent warns that this warm solution can start reacting early in the pipe on its way to the reactor.","inputs":["acrylic-acid","caustic-soda"]},{"name":"Set into a wet gel","process":"react","text":"An initiator starts the chains, and the cross-linker ties them into a net. More cross-linking gives a firmer gel that swells less, and less gives a softer, stickier one that holds more. One patent puts the finished hydrogel at about 40 to 80% water.","inputs":[]},{"name":"Chop the rubbery mass","process":"cut","text":"A cutter mill or chopper breaks the gel into coarse lumps, 2 to 10 mm in one patent. Pieces that size dry faster, and going much finer is hard because the wet bits stick together.","inputs":[]},{"name":"Dry with hot air","process":"dry","text":"Hot air or infrared drives the water out of the lumps. If the dryer runs too hot, only the outside dries, and the grinder makes unwanted fines later. The polymer leaves as a solid with little moisture left in it.","inputs":[]},{"name":"Grind and sieve the grains","process":"crush","text":"Pin, hammer or roll mills reduce the dry solid to powder. Sieves then keep the wanted size range and send only those grains forward.","inputs":[],"spec":"150 to 850 µm in one patent"},{"name":"Cross-link each grain's surface","process":"coat","text":"The powder is sprayed with or stirred into a cross-linking solution, then heat treated, which forms a second set of links in the outer layer of each grain. Too much agent over-links the surface and hurts the finished properties.","inputs":[]}],"facts":["In the early 1960s, US Department of Agriculture researchers trying to conserve water in soil made a starch-based resin that absorbed over 400 times its weight.","Until the 1920s, the best absorbers were fiber products such as tissue, cotton and sponge, which hold up to about eleven times their weight.","In a 0.9% saline solution, absorbency falls from about 300 times the polymer's weight to about 50."],"where":[],"whereNote":null,"sources":[{"title":"Superabsorbent polymer","url":"https://en.wikipedia.org/wiki/Superabsorbent_polymer"},{"title":"US10894245, Method for preparing superabsorbent polymer","url":"https://patents.google.com/patent/US10894245"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"surfboard","name":"Surfboard","kind":"product","category":"play","title":"How surfboards are made","url":"https://assemblyline.org/make/surfboard","stations":8,"upstream":37,"downstream":0,"depth":7,"dek":"A surfboard is carved from a block of foam, then sealed in fiberglass cloth and resin.","answer":"A surfboard starts as a block of foam, called a blank, with a thin wooden strip down the middle. A shaper cuts and sands it to the final outline and curves. The board is wrapped in fiberglass cloth soaked in resin. Fins and a leash plug are added, and the surface is glossed and sanded.","aka":["surf board","shortboard","longboard"],"inputs":["polyurethane","polystyrene","timber","fiberglass","epoxy"],"uses":[],"grounds":["timber","water","silica-sand","limestone","crude-oil","air","rock-salt","natural-gas","trona","sulfur","coal","corn","sugarcane","sugar-beet"],"upstreamSlugs":["polyurethane","polystyrene","timber","fiberglass","epoxy","propylene","nitric-acid","chlorine","water","naphtha","ethylene","benzene","styrene","silica-sand","limestone","soda-ash","phenol","acetone","caustic-soda","crude-oil","ammonia","air","rock-salt","sulfuric-acid","hydrogen","natural-gas","toluene","carbon-dioxide","lime","trona","sulfur","coal","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the foam blank","process":"mold","text":"Polyurethane foam is molded into a blank in the rough shape of a board. Some blanks are polystyrene foam instead, which weighs less.","inputs":["polyurethane","polystyrene"]},{"name":"Set in the wooden stringer","process":"assemble","text":"A thin, stiff slat of wood runs from nose to tail down the middle, adding strength. Some blanks have one or more stringers.","inputs":["timber"]},{"name":"Cut the outline","process":"cut","text":"The blank is cut to the board's outline in plan view, either by a machine or by a shaper with a saw.","inputs":[]},{"name":"Shape the curves","process":"machine","text":"The shaper planes down the foam to give the board its rocker, rails and bottom contours. Polyurethane is brittle, so it is easy to form by hand with sandpaper.","inputs":[]},{"name":"Wrap in fiberglass and resin","process":"laminate","text":"Fiberglass cloth is draped over the foam and brushed with resin. Polyester resin is used with polyurethane foam, but it would melt polystyrene foam, so those boards use epoxy resin.","inputs":["fiberglass","epoxy"]},{"name":"Let the resin cure","process":"dry","text":"The resin hardens into a hard, clear skin. The shell is light and strong enough to take a beating from waves.","inputs":[]},{"name":"Install fins and leash plug","process":"assemble","text":"Fin boxes or fixed fins are glassed onto the bottom, and a plug for the leash goes in near the tail.","inputs":[]},{"name":"Sand and gloss","process":"grind","text":"A final coat of resin is sanded and polished smooth. Surfers apply wax to the deck themselves.","inputs":[]}],"facts":["Balsa wood was long considered perfect for surfboards, but fiberglass skins made foam blanks practical after World War II.","Fin choices were made adjustable, so surfers can change how a board rides by changing its fins."],"where":[],"whereNote":null,"sources":[{"title":"Surfboard","url":"https://en.wikipedia.org/wiki/Surfboard"},{"title":"Polyurethane foam","url":"https://en.wikipedia.org/wiki/Polyurethane_foam"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"suspension-bridge-cable","name":"Suspension bridge cable","kind":"product","category":"metals","title":"How suspension bridge cables are made","url":"https://assemblyline.org/make/suspension-bridge-cable","stations":7,"upstream":65,"downstream":0,"depth":10,"dek":"Bridge cables are spun in midair, as a wheel shuttles back and forth laying down wires one at a time.","answer":"A main bridge cable is built in place from thousands of zinc-coated high-strength steel wires. A traveling wheel carries each wire across between anchorages, usually 400 to 500 wires to a strand and 30 to 90 strands to a cable. Hydraulic compactors squeeze the bundle round, soft galvanized wire wraps it, and clamped bands carry the suspenders.","aka":["main cable","bridge cable"],"inputs":["steel-wire","zinc","paint","wire-rope"],"uses":[],"grounds":["zinc-ore","air","water","sulfur","titanium-ore","iron-ore","limestone","dolomite","manganese-ore","natural-gas","rock-salt","coal","crude-oil","quartz","timber","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["steel-wire","zinc","paint","wire-rope","steel","zinc-ore","air","sulfuric-acid","water","titanium-dioxide","pigment","acrylic","tin-can","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","sulfur","titanium-ore","chlorine","coke","iron-ore","carbon-black","propylene","ammonia","methanol","tinplate","lacquer","ink","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","rock-salt","coal","crude-oil","naphtha","tin","ethanol","vegetable-oil","phenolic-resin","quartz","charcoal","timber","hydrogen","tin-ore","corn","sugarcane","yeast","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","molasses","benzene","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Coat the steel wire","process":"coat","text":"The cable starts as thin, high-strength steel wire with a zinc coating to keep off corrosion.","inputs":["steel-wire","zinc"]},{"name":"Pull across a pilot line","process":"assemble","text":"With towers and anchorages built, and saddles on the tower tops, a light pilot rope crosses the span by boat or helicopter. It then hauls progressively heavier lines over.","inputs":[]},{"name":"Spin the wires","process":"spin","text":"A traveling wheel runs back and forth between the anchorages, laying down one wire at a time. Each wire is tensioned individually, and instruments keep watch, since small length errors change how the whole span behaves.","inputs":[]},{"name":"Bundle into strands","process":"assemble","text":"Conventionally, 400 to 500 wires make one strand and 30 to 90 strands make a main cable. Each strand is anchored at both ends, in bedrock tunnels where rock allows or in huge concrete anchorages.","inputs":[],"spec":"400 to 500 wires per strand"},{"name":"Squeeze the bundle round","process":"press","text":"Hydraulic compactors press the strands into a tight, circular cross-section.","inputs":[]},{"name":"Wrap and seal","process":"coat","text":"Soft galvanized wire is wound around the compacted bundle and painted with elastomeric coating to shed weather. Some bridges also blow dry air through the voids to keep humidity below 40 percent.","inputs":["steel-wire","paint"]},{"name":"Clamp on the suspenders","process":"assemble","text":"Bands are clamped around the main line at set intervals, and vertical suspender cables hang from them to carry the deck segments.","inputs":["wire-rope"]}],"facts":["The Spider Bridge at Falls of Schuylkill, from 1816, was the first of its kind hung on wire cable.","Marc Seguin and his brothers built a temporary wire-cable bridge at Annonay in 1822 that spanned just 18 m.","Some projects skip spinning altogether and lay prefabricated strands, shipped in coils and carrying hot-cast anchors on each end."],"where":[],"whereNote":null,"sources":[{"title":"Suspension bridge","url":"https://en.wikipedia.org/wiki/Suspension_bridge"},{"title":"US10584453B2: Method for fabricating wire strand for main cable of suspension bridge","url":"https://patents.google.com/patent/US10584453B2/en"},{"title":"Main cables, Ponte di Messina","url":"https://pontedimessina.it/en/main-cables/"},{"title":"Suspension Bridge Design and Construction, Build Construct","url":"https://build-construct.com/building/suspension-bridge-design-and-construction-structural-components-building-process-and-engineering-facts/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"swimsuit","name":"Swimsuit","kind":"product","category":"textiles","title":"How swimsuits are made","url":"https://assemblyline.org/make/swimsuit","stations":9,"upstream":35,"downstream":0,"depth":8,"dek":"At one Los Angeles factory, the cloth rests on long tables for days before a worker saws through the stack.","answer":"Swim fabric is mostly nylon with 10 to 20 percent spandex, and it gets cut with surprising patience: rolled out, rested for days, then stacked and sawn. Machinists on an assembly line sew one section each. A polyester liner is basted in, and elastic is stretched into the leg and neck openings before a twin needle topstitches it down.","aka":["bathing suit","swimwear","swimming costume"],"inputs":["nylon","polyurethane","spandex","polyester","thread"],"uses":[],"grounds":["water","air","natural-gas","crude-oil","rock-salt","coal","sulfur","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["nylon","polyurethane","spandex","polyester","thread","benzene","nitric-acid","ammonia","propylene","chlorine","water","formaldehyde","ethylene-glycol","pet-plastic","naphtha","hydrogen","toluene","air","natural-gas","crude-oil","rock-salt","sulfuric-acid","methanol","ethylene","oxygen","carbon-dioxide","p-xylene","coal","sulfur","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Rest the rolled cloth","process":"roll","text":"Shell fabric arrives as a blend of roughly 80 to 90 percent nylon with 10 to 20 percent spandex, solid or printed. At the Los Angeles factory sewing for the Lime Ricki brand, it is spread on long tables and left for a few days to flatten and relax.","inputs":["nylon","polyurethane","spandex"]},{"name":"Stack and saw","process":"cut","text":"The rested cloth is layered several inches deep, a pattern goes on top, and a worker hand-cuts through the pile with a special saw. Abely, a maker in China, uses a cutting machine for bulk runs instead.","inputs":[]},{"name":"Cut lining and trim","process":"cut","text":"Lining, trim and elastic are cut as separate pieces. Soft lining is usually all polyester.","inputs":["polyester"]},{"name":"Sew the main seams","process":"sew","text":"Machinists join the straps, sides and crotch with a zigzag or stretch stitch, which copes with pulling far better than a straight one. Thread is polyester or woolly nylon, since cotton gives too little and suffers in chlorine and salt water. On an assembly line, each machinist handles one part of the suit.","inputs":["thread"]},{"name":"Baste in the liner","process":"sew","text":"The liner slides in through the neck, and its seams are matched to the suit's at the crotch, sides and straps. A temporary running stitch holds the two together at every opening until the end.","inputs":[]},{"name":"Stretch on the elastic","process":"sew","text":"Elastic goes around the neck and leg openings at about 25 percent stretch. Only the elastic is pulled, and the suit cloth lies relaxed under the needle.","inputs":[]},{"name":"Topstitch the edges","process":"sew","text":"The elastic is folded into the suit and a twin needle runs over it, the last stitching the garment gets. A seam ripper then removes the basting thread.","inputs":["thread"]},{"name":"Inspect each suit","process":"inspect","text":"Every finished suit gets its own check, and any that falls short is held back from customers.","inputs":[]},{"name":"Fold and pack","process":"package","text":"Approved suits are folded and packaged by hand, then shipped to the warehouse.","inputs":[]}],"facts":["Spandex began to be used in swimsuits in the 1960s, almost always blended with nylon.","Spandex is not especially durable, and chlorinated water in pools and hot tubs wears it down faster.","Cotton thread is a poor choice for a swimsuit, because it has too little stretch and holds up badly in chlorinated or salt water."],"where":[],"whereNote":null,"sources":[{"title":"The Lime Ricki Swimsuit Process","url":"https://limericki.com/blogs/resources/how-our-swimwear-is-made"},{"title":"How do swimwear manufacturers produce swimsuits?, Abely","url":"https://www.abelyfashion.com/how-do-swimwear-manufacturers-produce-swimsuits.html"},{"title":"Swimwear","url":"https://en.wikipedia.org/wiki/Swimwear"},{"title":"Elastane","url":"https://en.wikipedia.org/wiki/Elastane"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"synthetic-graphite","name":"Synthetic graphite","kind":"material","category":"chemicals","title":"How synthetic graphite is made","url":"https://assemblyline.org/make/synthetic-graphite","stations":6,"upstream":3,"downstream":13,"depth":2,"dek":"Synthetic graphite is coke baked in an electric furnace until its carbon atoms rearrange into sheets.","answer":"Synthetic graphite is made from petroleum coke and coal tar pitch. The coke is calcined, ground and mixed with pitch, shaped into blocks, and baked. The blocks are then passed through a furnace heated by electric current to above 2,100 °C, where the carbon atoms rearrange into stacked graphite layers.","aka":["artificial graphite","Acheson graphite","electrographite"],"inputs":["crude-oil","petroleum-coke","coal"],"uses":["lithium-ion-cell","synthetic-diamond"],"grounds":["crude-oil","coal"],"upstreamSlugs":["crude-oil","petroleum-coke","coal"],"downstreamSlugs":["lithium-ion-cell","synthetic-diamond","ev-battery","smartphone","laptop","drone","satellite","smartwatch","wireless-earbuds","digital-camera","e-reader","electric-toothbrush","electric-car"],"steps":[{"name":"Calcine the coke","process":"fire","text":"Raw petroleum coke, the solid left behind when a refinery cooks heavy crude oil, is heated to drive off volatile matter. What is left is a hard, nearly pure carbon.","inputs":["crude-oil","petroleum-coke"]},{"name":"Grind and mix with pitch","process":"mix","text":"Coke is milled to a controlled grain size and kneaded with hot pitch, a sticky binder from coal. The grain mix decides the strength of the finished graphite.","inputs":["coal"]},{"name":"Press it into blocks","process":"extrude","text":"Warm paste is extruded or molded into green blocks or rods. At this point they are crumbly carbon held together by pitch.","inputs":[]},{"name":"Bake the blocks","process":"fire","text":"The blocks are baked slowly in a furnace for weeks, which turns the pitch into hard carbon. They are often soaked in more pitch and baked again to fill pores.","inputs":[]},{"name":"Graphitize in an electric furnace","process":"heat-treat","text":"Electric current passes straight through the blocks, which are packed in coke. They are heated above 2,100 °C, and carbon atoms shuffle into the layered graphite structure.","inputs":[],"spec":"above 2,100 °C"},{"name":"Machine to size","process":"machine","text":"The finished graphite is soft enough to be cut and turned on lathes. Electrodes, battery anode powder and crucibles are among the products.","inputs":[]}],"facts":["Edward Goodrich Acheson patented his process for making graphite and silicon carbide in 1896.","In 1890, Acheson tried to make diamond and ended up with blue silicon carbide crystals that he called carborundum."],"where":[],"whereNote":null,"sources":[{"title":"Graphite","url":"https://en.wikipedia.org/wiki/Graphite"},{"title":"Acheson process","url":"https://en.wikipedia.org/wiki/Acheson_process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"synthetic-rubber","name":"Synthetic rubber","kind":"material","category":"plastics","title":"How synthetic rubber is made","url":"https://assemblyline.org/make/synthetic-rubber","stations":6,"upstream":10,"downstream":45,"depth":6,"dek":"The most common synthetic rubber is a copolymer of styrene and butadiene, made in giant vats of soapy water.","answer":"Synthetic rubber is made by linking petrochemical monomers into elastic chains. For styrene-butadiene rubber, butadiene and styrene are emulsified in soapy water and polymerized into a milky latex. Acid and salt coagulate the latex into crumbs, which are washed, dried and pressed into bales.","aka":["SBR","styrene-butadiene rubber","man-made rubber"],"inputs":["naphtha","benzene","ethylene","styrene","water"],"uses":["toothbrush","syringe","rubber","nitrile-glove","chewing-gum","tire","golf-ball","basketball","pencil-eraser","flip-flops","rubber-boots"],"grounds":["water","crude-oil","natural-gas","coal"],"upstreamSlugs":["naphtha","benzene","ethylene","styrene","water","crude-oil","hydrogen","toluene","natural-gas","coal"],"downstreamSlugs":["toothbrush","syringe","rubber","nitrile-glove","chewing-gum","tire","golf-ball","basketball","pencil-eraser","flip-flops","rubber-boots","computer-keyboard","vacuum-cleaner","electric-kettle","pencil","shipping-container","tennis-ball","baseball","soccer-ball","ski","snowboard","roller-skates","golf-club","football","volleyball","cricket-bat","dumbbell","treadmill","wheelchair","ladder","wheelbarrow","fire-extinguisher","hiking-boots","high-heels","loudspeaker","inkjet-printer","electric-toothbrush","sneaker","leather-shoe","umbrella","car","electric-car","bicycle","motorcycle","laptop"],"steps":[{"name":"Collect butadiene from the cracker","process":"refine","text":"A steam cracker running on naphtha produces butadiene alongside ethylene. It is separated by distillation and kept under pressure as a liquid.","inputs":["naphtha"]},{"name":"Make styrene","process":"react","text":"Styrene is built from benzene and ethylene at a nearby plant. It is the second half of the most common synthetic rubber.","inputs":["benzene","ethylene","styrene"]},{"name":"Emulsify and polymerize","process":"react","text":"The monomers are stirred into water with soap-like emulsifiers and an initiator in a train of reactors. Rubbery particles grow inside tiny droplets until the mixture is milky latex.","inputs":["water"]},{"name":"Strip the leftovers","process":"refine","text":"Unreacted monomers are boiled out of the latex and recycled. Antioxidants are added so the rubber will last in storage.","inputs":[]},{"name":"Coagulate into crumb","process":"separate","text":"Acid and salt break the latex, and rubber clumps float out as crumb. The crumb is washed free of soap and other residues.","inputs":[]},{"name":"Dry and press into bales","process":"press","text":"Crumb travels through a long dryer and is compressed into bales wrapped in plastic. Tire factories buy them by the truckload.","inputs":[]}],"facts":["Studies published in 1930 by Sergey Lebedev, Wallace Carothers and Hermann Staudinger helped lead to the synthetic rubber neoprene in 1931.","By mid-1942 the Axis powers controlled almost all the world's natural rubber supply, which pushed the United States to expand synthetic rubber production during World War II."],"where":[],"whereNote":null,"sources":[{"title":"Synthetic rubber","url":"https://en.wikipedia.org/wiki/Synthetic_rubber"},{"title":"Styrene","url":"https://en.wikipedia.org/wiki/Styrene"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"syringe","name":"Syringe","kind":"product","category":"body-health","title":"How syringes are made","url":"https://assemblyline.org/make/syringe","stations":7,"upstream":80,"downstream":0,"depth":11,"dek":"A disposable syringe is three plastic and rubber parts molded by machines that run around the clock.","answer":"A disposable syringe has a clear plastic barrel, a plunger and a rubber tip that seals the two. Machines mold the barrel and plunger from polypropylene, print the volume scale, and fit the rubber tip. A hypodermic needle, drawn from stainless steel tube, is added before the sterilized syringe is sealed in its pack.","aka":["hypodermic syringe","disposable syringe","needle and syringe"],"inputs":["polypropylene","ink","synthetic-rubber","silicone","stainless-steel","plastic-bag"],"uses":[],"grounds":["water","silica-sand","crude-oil","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","natural-gas","quartz","coal","timber","chromite","limestone","nickel-ore","rock-salt","trona","sugar-beet","bauxite"],"upstreamSlugs":["polypropylene","ink","synthetic-rubber","silicone","stainless-steel","plastic-bag","propylene","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","naphtha","benzene","ethylene","styrene","silicon","methanol","hydrochloric-acid","silica-sand","steel-scrap","chromium","nickel","oxygen","argon","polyethylene","cardboard-box","crude-oil","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","hydrogen","toluene","natural-gas","quartz","coal","charcoal","timber","propane","chromite","soda-ash","limestone","aluminum","nickel-ore","cardboard","adhesive","rock-salt","molasses","ammonia","carbon-dioxide","lime","trona","petroleum-coke","alumina","wood-pulp","acrylic","epoxy","polyurethane","paraffin-wax","sugar-beet","bauxite","caustic-soda","hydrogen-peroxide","acetone","nitric-acid"],"downstreamSlugs":[],"steps":[{"name":"Mold the barrel","process":"mold","text":"Polypropylene pellets are melted and injected into a steel mold cavity. The mold is cooled, opens and drops out a clear tube with a flange and a tip.","inputs":["polypropylene"]},{"name":"Mold the plunger","process":"mold","text":"A second machine molds the plunger, a cross-shaped rod with a thumb pad on one end. Its shape resists bending while it slides.","inputs":[]},{"name":"Print the scale","process":"print","text":"Ink is applied to the barrel to mark volume, with a precision that clinicians depend on for dosing.","inputs":["ink"]},{"name":"Make the rubber seal","process":"mold","text":"A rubber tip is molded so it fits the barrel wall with no gaps. A thin film of silicone oil coats the barrel so the plunger glides.","inputs":["synthetic-rubber","silicone"]},{"name":"Draw the needle tube","process":"draw","text":"Stainless steel tube is drawn through progressively smaller dies until it reaches the needle gauge. It is cut into lengths and the end is ground to a sharp bevel.","inputs":["stainless-steel"]},{"name":"Assemble the parts","process":"assemble","text":"Robots push the seal onto the plunger, slide the plunger into the barrel, and fit the needle hub with its protective cap.","inputs":[]},{"name":"Sterilize and seal","process":"pasteurize","text":"Packed syringes are sterilized in their wrappers. Sealing them first means they stay sterile until opened.","inputs":["plastic-bag"]}],"facts":["In 1853, Charles Pravaz and Alexander Wood independently developed syringes fitted with a needle fine enough to pierce the skin.","In 1951, Rothauser produced the first injection-moulded polypropylene syringes, a plastic that can be heat-sterilized.","Hypodermic needles are made from stainless steel or niobium tube, which is drawn through progressively smaller dies."],"where":[],"whereNote":null,"sources":[{"title":"Syringe","url":"https://en.wikipedia.org/wiki/Syringe"},{"title":"Hypodermic needle","url":"https://en.wikipedia.org/wiki/Hypodermic_needle"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"t-shirt","name":"T-shirt","kind":"product","category":"textiles","title":"How T-shirts are made","url":"https://assemblyline.org/make/t-shirt","stations":6,"upstream":47,"downstream":0,"depth":8,"dek":"A T-shirt is knit from a single continuous yarn that loops through itself row after row.","answer":"A T-shirt is cut from knit jersey. A circular knitting machine loops cotton yarn into a stretchy tube of fabric. The fabric is dyed, cut into panels, sewn at shoulders, sleeves and hem, and often screen-printed with a design.","aka":["tee","tee shirt","jersey shirt"],"inputs":["cotton-yarn","water","thread","ink"],"uses":[],"grounds":["water","raw-cotton","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","coal","natural-gas","sugar-beet","limestone"],"upstreamSlugs":["cotton-yarn","water","thread","ink","raw-cotton","polyester","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","pet-plastic","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","ethylene","p-xylene","ethylene-glycol","hydrogen","benzene","propylene","methanol","rock-salt","coal","molasses","naphtha","natural-gas","carbon-dioxide","toluene","sugar-beet","limestone"],"downstreamSlugs":[],"steps":[{"name":"Loop the jersey","process":"weave","text":"A knitting machine loops cotton yarn into stretchy jersey fabric. Each loop is pulled through the one before it, which is why the fabric stretches.","inputs":["cotton-yarn"]},{"name":"Dye the fabric","process":"dye","text":"The knitted fabric is bleached or soaked in dye baths before cutting. The color must be fixed so it does not wash away.","inputs":["water"]},{"name":"Cut out the panels","process":"cut","text":"Blades cut layers of fabric into the front, back, sleeves and neck rib. The shape that gives the shirt its name is a T.","inputs":[]},{"name":"Sew it together","process":"sew","text":"Sewers close the shoulders, set in the sleeves, attach the collar band and hem the sleeves and bottom. Knit fabric stretches, so the stitches have to stretch too.","inputs":["thread"]},{"name":"Screen-print the design","process":"print","text":"In screen printing, each color is pushed through its own mesh screen, partly coated with emulsion to block the non-image area. Ink sits on top of the fabric until a dryer cures it.","inputs":["ink"]},{"name":"Fold and pack","process":"package","text":"Shirts are inspected, folded, tagged and bagged for shipping.","inputs":[]}],"facts":["About two billion T-shirts are sold worldwide each year, and the average person in Sweden buys nine a year.","The invention of plastisol ink in 1959 gave printers a more durable and stretchable ink than water-based inks, and most prefer it."],"where":[],"whereNote":null,"sources":[{"title":"T-shirt","url":"https://en.wikipedia.org/wiki/T-shirt"},{"title":"Knitting","url":"https://en.wikipedia.org/wiki/Knitting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"table-salt","name":"Table salt","kind":"product","category":"minerals","title":"How table salt is made","url":"https://assemblyline.org/make/table-salt","stations":5,"upstream":2,"downstream":47,"depth":1,"dek":"Only about 17.5% of the world's salt goes into food. The rest goes to chemical plants, road de-icing and water treatment.","answer":"Table salt comes from seawater or underground salt beds. Seawater is evaporated in shallow pools, and deep deposits are mined or dissolved into brine and boiled down. Chemicals are added to drop out magnesium and calcium. The brine is evaporated in vacuum pans, then iodine and an anti-caking agent are mixed in.","aka":["iodized salt","sodium chloride","kitchen salt"],"inputs":["rock-salt","seawater"],"uses":["butter","cheese","margarine","mayonnaise","ketchup","mustard","soy-sauce","peanut-butter","bread","instant-noodles","croissant","pretzel","corn-flakes","potato-chips","popcorn","hot-dog","bacon","canned-tuna","chicken-nuggets","cream-cheese","mozzarella","parmesan","cheddar","oat-milk","hot-sauce","salsa","pickles","sauerkraut","kimchi","bagel","baguette","sourdough","crackers","imitation-crab","sausage","salami","ham","beef-jerky","canned-meat","sausage-casing","modeling-clay","caramel","cake-mix","dish-soap"],"grounds":["rock-salt","seawater"],"upstreamSlugs":["rock-salt","seawater"],"downstreamSlugs":["butter","cheese","margarine","mayonnaise","ketchup","mustard","soy-sauce","peanut-butter","bread","instant-noodles","croissant","pretzel","corn-flakes","potato-chips","popcorn","hot-dog","bacon","canned-tuna","chicken-nuggets","cream-cheese","mozzarella","parmesan","cheddar","oat-milk","hot-sauce","salsa","pickles","sauerkraut","kimchi","bagel","baguette","sourdough","crackers","imitation-crab","sausage","salami","ham","beef-jerky","canned-meat","sausage-casing","modeling-clay","caramel","cake-mix","dish-soap","toffee","fish-sticks","frozen-pizza"],"steps":[{"name":"Find the salt","process":"mine","text":"Salt comes from mines in ancient seabed deposits, from spring water, or from seawater, which carries about 35 g of dissolved salts per kilogram. Deposits can also be dissolved by pumping water underground and bringing the brine up.","inputs":["rock-salt","seawater"]},{"name":"Clean the brine","process":"refine","text":"The raw salt is dissolved and treated with chemicals that precipitate most of the impurities, mostly magnesium and calcium salts.","inputs":[]},{"name":"Evaporate it in a vacuum pan","process":"cook","text":"Multiple stages of evaporation boil the water off. In the Alberger process, a vacuum pan evaporates the brine while cubic crystals seed the solution, which grows a grainy flake salt.","inputs":[]},{"name":"Mix in the additives","process":"mix","text":"Table salt often has iodine added, at 46–77 ppm in the US. An anti-caking agent such as magnesium carbonate, used since at least 1911, keeps it flowing.","inputs":[],"spec":"46–77 ppm iodine in US salt"},{"name":"Dry, pack and ship","process":"package","text":"The salt is dried, screened and packed in cartons, canisters and bags.","inputs":[]}],"facts":["Around 6000 BC, people in what is now Romania boiled spring water to extract salt.","The Sifto mine in Ontario sits about 550 meters below Lake Huron and yields about seven million tons of salt a year.","The Khewra Salt Mine in Pakistan has 400 km of passages."],"where":[{"place":"China","share":"68 million tonnes"},{"place":"United States","share":"42 million tonnes"},{"place":"India","share":"29 million tonnes"},{"place":"Germany","share":"13 million tonnes"},{"place":"Canada","share":"13 million tonnes"}],"whereNote":"2018 production, in a world total of 300 million tonnes.","sources":[{"title":"Salt","url":"https://en.wikipedia.org/wiki/Salt"},{"title":"Sea salt","url":"https://en.wikipedia.org/wiki/Sea_salt"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"suit","name":"Tailored suit","kind":"product","category":"textiles","title":"How tailored suits are made","url":"https://assemblyline.org/make/suit","stations":7,"upstream":43,"downstream":0,"depth":8,"dek":"Inside a good suit jacket sits a hidden layer of canvas, often horsehair, that gives the chest its curve.","answer":"Suit cloth is woven from wool yarn, most often worsted, whose fibers are combed before spinning for a smooth, hard-wearing finish. Cutters lay patterns on the cloth, and tailors build a canvas structure inside the jacket that gives it shape. Panels are sewn together, then steam-pressed into curves.","aka":["tailored suit","business suit","two-piece suit"],"inputs":["fleece","wool-yarn","adhesive","thread","button"],"uses":[],"grounds":["fleece","water","crude-oil","natural-gas","air","sulfur","rock-salt","coal","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["fleece","wool-yarn","adhesive","thread","button","water","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","polyester","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","pet-plastic","naphtha","natural-gas","air","sulfur","benzene","rock-salt","p-xylene","ethylene-glycol","toluene","oxygen","carbon-dioxide","coal","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Comb and spin the wool","process":"spin","text":"For worsted yarn, wool fibers are combed so they lie parallel before spinning. The result is a smooth, hard yarn that makes a cloth with a clean surface. Woolen yarn skips the combing and stays fuzzier.","inputs":["fleece"]},{"name":"Weave the suiting cloth","process":"weave","text":"Looms weave the yarn into the twill or plain weave that gives the cloth its pattern. The weave and the weight of the yarn decide whether the suit is a heavy winter cloth or a light summer one.","inputs":["wool-yarn"]},{"name":"Shrink and finish the cloth","process":"wash","text":"The woven cloth is washed, steamed and pressed so it will not shrink or twist later. A suit made from unfinished cloth would shrink the first time it met steam.","inputs":[]},{"name":"Cut the pieces","process":"cut","text":"Each yard of cloth is inspected, then cut by machine or by hand. Stripes and checks are hand cut so the pattern lines up across pockets, flaps and seams, which wastes more cloth but looks better.","inputs":[]},{"name":"Build the jacket canvas","process":"laminate","text":"Canvas is soaked and air dried, then shaped and attached inside the front of the jacket, either stitched or fused with adhesive. It gives the chest and lapel their curve and keeps the jacket balanced on the body.","inputs":["adhesive"]},{"name":"Sew the jacket and trousers","process":"sew","text":"The panels are joined, the lining is stitched into the jacket, the sleeves are set into the shoulders, and the trouser legs are attached to the waistband. Pockets and buttonholes are among the last details sewn.","inputs":["thread","button"]},{"name":"Press into shape","process":"press","text":"Steam presses and hot irons mold the finished jacket over curved forms. The heat and moisture relax the wool so the lapels roll and the shoulders keep their shape, and each suit is inspected before it leaves.","inputs":[]}],"facts":["Worsted and woolen cloth start from the same raw wool, but only worsted yarn is combed before spinning.","Joseph Abboud's factory in Massachusetts counts 147 operations to complete a garment."],"where":[],"whereNote":null,"sources":[{"title":"Suit (clothing)","url":"https://en.wikipedia.org/wiki/Suit_(clothing)"},{"title":"Wool","url":"https://en.wikipedia.org/wiki/Wool"},{"title":"A visit to our tailoring factory (Drake's)","url":"https://www.drakes.com/blogs/news/handmade-in-veneto-a-visit-to-our-tailoring-factory"},{"title":"Inside the Joseph Abboud factory (The Manual)","url":"https://themanual.com/fashion/inside-joseph-abboud-factory-massachusetts"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tampon","name":"Tampon","kind":"product","category":"body-health","title":"How tampons are made","url":"https://assemblyline.org/make/tampon","stations":7,"upstream":50,"downstream":0,"depth":9,"dek":"Tampon absorbency is tested on a machine called the Syngyna, which is short for synthetic vagina.","answer":"Most tampons are made from rayon or a rayon and cotton blend. A strip of absorbent fiber is rolled or folded into a blank, compressed into a cylinder called a pledget and heat set so it holds its shape. A withdrawal string is attached, many are fitted into an applicator, and each is wrapped and packaged for sale.","aka":["menstrual tampon","tampons"],"inputs":["rayon","raw-cotton","thread","plastic","cardboard","paper"],"uses":[],"grounds":["raw-cotton","water","natural-gas","kaolin","limestone","timber","rock-salt","sulfur","air","crude-oil","corn","coal","sugarcane","sugar-beet"],"upstreamSlugs":["rayon","raw-cotton","thread","plastic","cardboard","paper","wood-pulp","caustic-soda","sulfuric-acid","water","polyester","naphtha","natural-gas","ethylene","propylene","adhesive","kaolin","limestone","timber","lime","oxygen","hydrogen-peroxide","rock-salt","sulfur","air","pet-plastic","crude-oil","hydrogen","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","p-xylene","ethylene-glycol","ammonia","methanol","phenol","acetone","chlorine","nitric-acid","carbon-dioxide","benzene","corn","yeast","toluene","molasses","coal","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Prepare the fibers","process":"mix","text":"Rayon, which is cellulose from wood pulp, and cotton are the usual absorbent fibers. They are blended and laid into a loose strip, in proportions that help set the absorbency.","inputs":["rayon","raw-cotton"]},{"name":"Roll the strip","process":"press","text":"A rectangular strip of the material is rolled or folded into a blank, sometimes with a cover layer around it.","inputs":[]},{"name":"Compress the pledget","process":"press","text":"The blank is squeezed into a narrow cylinder called a pledget and heat set so it stays that shape until it meets fluid. Applicator tampons expand along their length while digital ones expand across their width.","inputs":[]},{"name":"Attach the string","process":"sew","text":"A withdrawal string is fixed to one end of the pledget. Mercerized cotton is a common choice for the string.","inputs":["thread"]},{"name":"Add an applicator","process":"assemble","text":"Applicator tampons are placed inside a tube made of plastic or cardboard. Digital tampons skip this step.","inputs":["plastic","cardboard"]},{"name":"Test the absorbency","process":"inspect","text":"Samples are tested on the Syngyna, in which a tampon sits in a condom while synthetic menstrual fluid is fed in. The result sets the absorbency rating printed on the pack.","inputs":[]},{"name":"Wrap and box","process":"package","text":"Each tampon is wrapped and boxed, and the FDA requires the absorbency rating on the label.","inputs":["paper"]}],"facts":["Toxic shock syndrome was named by James K. Todd in 1978.","In 1992 the US Congress found an FDA memo about dioxin in tampons, a chemical made when wood pulp is bleached with chlorine."],"where":[],"whereNote":null,"sources":[{"title":"Tampon","url":"https://en.wikipedia.org/wiki/Tampon"},{"title":"US patent 5,084,038: tampon apparatus and method","url":"https://patents.google.com/patent/US5084038"},{"title":"US patent 8,530,721","url":"https://patents.google.com/patent/US8530721"},{"title":"The Facts on Tampons (FDA)","url":"https://www.fda.gov/consumers/consumer-updates/facts-tampons-and-how-use-them-safely"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tea-leaves","name":"Tea leaves","kind":"raw","category":"farm","title":"How tea leaves are grown and picked","url":"https://assemblyline.org/make/tea-leaves","stations":3,"upstream":0,"downstream":4,"depth":0,"dek":"Only the top 1 to 2 inches of a tea bush are picked, and the plant grows a fresh flush every 7 to 15 days.","answer":"Tea comes from the evergreen bush Camellia sinensis, grown in warm, rainy places and pruned to waist height. Pickers take only the top 25 to 50 millimeters of each shoot, the buds and young leaves called a flush. A bush sends up a new flush every 7 to 15 days in the growing season.","aka":["Camellia sinensis","tea farming","tea picking","tea harvest","tea plantation"],"inputs":[],"uses":["tea","green-tea","matcha"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["tea","green-tea","matcha","kombucha"],"steps":[{"name":"Prune to waist height","process":"grow","text":"Left alone, a tea plant grows into a tree up to 16 m tall. Growers prune it to waist height, which makes picking easier and gives the bush more new shoots with tender leaves. It needs at least 1,200 mm of rain a year and acidic soil.","inputs":[]},{"name":"Pluck the new flush","process":"harvest","text":"Only the top 25 to 50 mm of the mature plant is picked, the buds and young leaves known as a flush. A new one appears every 7 to 15 days in the growing season. Slower-growing leaves tend to give better flavor.","inputs":[],"spec":"top 25 to 50 mm"},{"name":"Cut by shears or machine","process":"harvest","text":"Plucking by hand was once the only method. Workers later used shears or sickles, and plantations adopted machines for low-grade tea in the twentieth century. At least 70 percent of tea bushes worldwide are now harvested by something other than hand plucking.","inputs":[]}],"facts":["Tea grown at elevations up to 2,000 m grows more slowly, but the leaves develop better flavor.","A new tea plant takes about three years before it is ready for harvesting.","China, India, Kenya and Sri Lanka together make 81% of world tea."],"where":[{"place":"China","share":"49% of world output"},{"place":"India","share":"20%"},{"place":"Kenya","share":"among the four biggest producers"},{"place":"Sri Lanka","share":"among the four biggest producers"}],"whereNote":"2022, share of the 29.8 million tonnes of tea produced worldwide.","sources":[{"title":"Tea","url":"https://en.wikipedia.org/wiki/Tea"},{"title":"Camellia sinensis","url":"https://en.wikipedia.org/wiki/Camellia_sinensis"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"teddy-bear","name":"Teddy bear","kind":"product","category":"textiles","title":"How teddy bears are made","url":"https://assemblyline.org/make/teddy-bear","stations":6,"upstream":20,"downstream":0,"depth":8,"dek":"Teddy bears are named after Theodore Roosevelt, after a 1902 hunting trip in Mississippi.","answer":"A teddy bear starts as flat pieces of plush cut from a pattern. The pieces are sewn inside out, turned right side out, and filled with soft stuffing. Eyes and nose are fastened securely, and joints or sewn limbs are attached. A last seam closes the opening and the bear is brushed and tagged.","aka":["stuffed bear","plush bear","teddy"],"inputs":["polyester","thread"],"uses":[],"grounds":["water","natural-gas","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["polyester","thread","pet-plastic","water","p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","oxygen","carbon-dioxide","crude-oil","hydrogen","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the plush pieces","process":"cut","text":"Dies or blades cut the head, body, arms, legs and ears from a roll of soft pile fabric. The pile on each piece has to run the same way, or the bear looks patchy.","inputs":["polyester"]},{"name":"Sew them inside out","process":"sew","text":"Matching pieces are stitched together with their furry sides facing in. Turning the pieces right side out later hides the seams.","inputs":["thread"]},{"name":"Fix eyes and nose","process":"assemble","text":"Eyes and a nose are attached before stuffing so they can be locked on from the back. Mass-produced bears for children must have securely fastened eyes.","inputs":[]},{"name":"Stuff with soft fill","process":"fill","text":"The body, head and limbs are packed with soft fiber filling through an opening. Many bears have safety joints for arms, legs and head, and others have sewn limbs.","inputs":["polyester"]},{"name":"Close the seam","process":"sew","text":"The last opening is stitched shut by hand or by machine so the seam hides in the pile.","inputs":["thread"]},{"name":"Brush, tag and pack","process":"package","text":"The fur is brushed, a tag is stitched on, and the bear is checked and bagged.","inputs":[]}],"facts":["Morris Michtom put a small soft bear cub in his New York candy-shop window with a sign reading Teddy's bear, and went on to found the Ideal Novelty and Toy Co.","The Steiff firm in Germany exhibited its bear at the Leipzig Toy Fair in March 1903.","The largest teddy bear measures 19.41 meters in length, and was built in Mexico in 2019."],"where":[],"whereNote":null,"sources":[{"title":"Teddy bear","url":"https://en.wikipedia.org/wiki/Teddy_bear"},{"title":"Sewing thread","url":"https://en.wikipedia.org/wiki/Sewing_thread"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"television","name":"Television","kind":"product","category":"electronics","title":"How televisions are made","url":"https://assemblyline.org/make/television","stations":6,"upstream":91,"downstream":0,"depth":10,"dek":"Only 0.5% of U.S. households had a television in 1946, and 90% had one by 1962.","answer":"A modern flat television is built around a display panel, either an LCD with an LED backlight or an OLED. A circuit board with a processor and memory drives the panel. The panel, boards, speakers and power supply are fixed into a thin frame and plastic housing, then tested with test patterns.","aka":["TV","flat-screen TV","LED TV","OLED TV"],"inputs":["lcd-screen","oled-screen","led","printed-circuit-board","microchip","abs-plastic","steel"],"uses":[],"grounds":["air","silica-sand","limestone","iron-ore","sulfur","crude-oil","coal","bauxite","zinc-ore","natural-gas","water","gold-ore","copper-ore","quartz","tin-ore","dolomite","manganese-ore","rock-salt","trona","titanium-ore","lead-ore","silver-ore","timber","corn","sugarcane","sugar-beet"],"upstreamSlugs":["lcd-screen","oled-screen","led","printed-circuit-board","microchip","abs-plastic","steel","glass","indium-tin-oxide","photoresist","pigment","acrylic","aluminum","gallium","indium","ammonia","hydrogen","gold","plastic","copper","fiberglass","epoxy","solder","silicon-wafer","oxygen","tin","naphtha","propylene","air","benzene","ethylene","styrene","pig-iron","magnesium","steel-scrap","lime","manganese","argon","silica-sand","soda-ash","limestone","phenolic-resin","iron-ore","titanium-dioxide","carbon-black","sulfur","sulfuric-acid","methanol","crude-oil","coal","petroleum-coke","alumina","bauxite","caustic-soda","zinc-ore","natural-gas","water","gold-ore","zinc","chlorine","copper-ore","phenol","acetone","lead","silver","polysilicon","quartz","tin-ore","coke","toluene","dolomite","silicon","propane","manganese-ore","rock-salt","carbon-dioxide","trona","formaldehyde","titanium-ore","lead-ore","silver-ore","hydrochloric-acid","trichlorosilane","nitrogen","charcoal","timber","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Make the display panel","process":"etch","text":"Glass is patterned with transistors in a clean fab, then joined with color filters and liquid crystal, or coated with organic light-emitting films.","inputs":["lcd-screen","oled-screen"]},{"name":"Attach the backlight","process":"assemble","text":"For LCD models, strips of white LEDs behind or beside the panel provide light, spread by a diffuser plate.","inputs":["led"]},{"name":"Mount the circuit boards","process":"assemble","text":"The main board with the processor and memory decodes pictures. Other boards handle power and the panel's timing.","inputs":["printed-circuit-board","microchip"]},{"name":"Mold the housing","process":"mold","text":"Plastic back covers and frames are injection-molded.","inputs":["abs-plastic"]},{"name":"Fit the stand and speakers","process":"assemble","text":"Speakers, a stand and a remote-control receiver join the panel in the frame.","inputs":["steel"]},{"name":"Test with patterns","process":"inspect","text":"Each set shows test patterns and is checked for dead pixels and color accuracy.","inputs":[]}],"facts":["By the early 2010s, flat LCD sets with LED backlights had largely replaced the glass picture tube.","Modern flat sets handle resolutions up to 8K."],"where":[],"whereNote":null,"sources":[{"title":"Television set","url":"https://en.wikipedia.org/wiki/Television_set"},{"title":"Liquid-crystal display","url":"https://en.wikipedia.org/wiki/Liquid-crystal_display"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tennis-ball","name":"Tennis ball","kind":"product","category":"play","title":"How tennis balls are made","url":"https://assemblyline.org/make/tennis-ball","stations":8,"upstream":36,"downstream":0,"depth":8,"dek":"A new tennis ball is pressurized, and it begins to go flat the moment its can is opened.","answer":"A tennis ball is a hollow rubber core covered in felt. Two rubber half-shells are molded and glued into a sphere, which is pressurized with gas. A woven felt of wool, nylon and cotton is glued round the core. The finished balls are sealed in pressurized cans so they keep their bounce.","aka":["tennis balls"],"inputs":["rubber","adhesive","wool-yarn","cotton-yarn","water"],"uses":[],"grounds":["water","natural-latex","sulfur","fleece","raw-cotton","crude-oil","air","natural-gas","rock-salt","coal"],"upstreamSlugs":["rubber","adhesive","wool-yarn","cotton-yarn","water","natural-latex","synthetic-rubber","carbon-black","sulfur","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","fleece","raw-cotton","naphtha","benzene","ethylene","styrene","crude-oil","air","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","hydrogen","toluene","natural-gas","rock-salt","coal"],"downstreamSlugs":[],"steps":[{"name":"Mix the rubber","process":"mix","text":"Rubber is blended with fillers and chemicals into a stiff dough, which is cut into small pieces, one for each half-shell.","inputs":["rubber"]},{"name":"Press the half-shells","process":"mold","text":"Each piece is pressed in a heated mold into a cup shape and cured.","inputs":[]},{"name":"Glue the halves together","process":"assemble","text":"Two cups are cemented rim to rim into a hollow sphere. Gas is sealed in at about 12 psi above the surrounding air pressure.","inputs":["adhesive"]},{"name":"Weave the felt","process":"weave","text":"The felt blends wool, nylon and cotton. Its surface slows the air flowing round the ball, which reduces drag.","inputs":["wool-yarn","cotton-yarn"]},{"name":"Cut the felt dumbbells","process":"cut","text":"Presses punch the felt into dumbbell-shaped pieces, two per ball. Their edges meet in the curved seam you see on a ball.","inputs":[]},{"name":"Glue on the felt","process":"laminate","text":"Cement is brushed on the core and the two felt pieces are pressed around it.","inputs":["adhesive"]},{"name":"Fluff and steam","process":"wash","text":"Steam and brushing raise the nap of the felt so the ball looks fuzzy and new.","inputs":["water"]},{"name":"Seal in pressurized cans","process":"package","text":"Balls are packed under pressure matching their own, which keeps the air inside from escaping until the can is opened.","inputs":[]}],"facts":["Tennis balls were white or black until 1972, when the ITF introduced yellow ones because they were easier to see on television.","Wimbledon kept using white balls until 1986.","In 1480 King Louis XI of France banned filling tennis balls with chalk, sand, sawdust or earth."],"where":[],"whereNote":null,"sources":[{"title":"Tennis ball","url":"https://en.wikipedia.org/wiki/Tennis_ball"},{"title":"Felt","url":"https://en.wikipedia.org/wiki/Felt"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tennis-racket","name":"Tennis racket","kind":"product","category":"play","title":"How tennis rackets are made","url":"https://assemblyline.org/make/tennis-racket","stations":9,"upstream":80,"downstream":0,"depth":10,"dek":"A racket frame is cured by blowing up a balloon inside it, in a heated mold.","answer":"A graphite racket starts as cold-stored sheets of carbon fiber soaked in resin. Workers cut about 15 pieces, roll them around a mandrel and a polyurethane tube, and bend the result into a hoop. In a hot mold, compressed air inflates the tube from inside and presses the layup against the walls while the resin cures. Drilling, paint and a grip follow.","aka":["tennis racquet","racquet"],"inputs":["carbon-fiber","epoxy","polyurethane","plastic","paint","leather","nylon"],"uses":[],"grounds":["air","water","natural-gas","cattle-hide","rock-salt","crude-oil","titanium-ore","iron-ore","sulfur","limestone","chromite","coal","trona","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","bauxite","dolomite","manganese-ore","quartz","timber","sugar-beet"],"upstreamSlugs":["carbon-fiber","epoxy","polyurethane","plastic","paint","leather","nylon","propylene","ammonia","air","phenol","acetone","chlorine","caustic-soda","nitric-acid","water","naphtha","natural-gas","ethylene","titanium-dioxide","pigment","acrylic","tin-can","cattle-hide","rock-salt","lime","chromium","benzene","crude-oil","sulfuric-acid","hydrogen","titanium-ore","coke","oxygen","iron-ore","carbon-black","sulfur","methanol","tinplate","lacquer","ink","limestone","chromite","soda-ash","aluminum","toluene","coal","steel","tin","ethanol","vegetable-oil","phenolic-resin","carbon-dioxide","trona","petroleum-coke","alumina","pig-iron","magnesium","steel-scrap","manganese","argon","tin-ore","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","formaldehyde","bauxite","dolomite","silicon","propane","manganese-ore","molasses","quartz","charcoal","timber","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut the cold prepreg","process":"cut","text":"Graphite sheets already carrying uncured resin, called prepreg, come out of cold storage and are cut into shapes. Each piece has a set fiber direction, and that direction largely decides how the racket plays. One Head model uses 15 pieces.","inputs":["carbon-fiber","epoxy"]},{"name":"Roll a tube around a bladder","process":"laminate","text":"Workers arrange the pieces on a table and roll them around a mandrel and a polyurethane tube. The mandrel sets the wall thickness, and the tube becomes the bladder that air will inflate.","inputs":["polyurethane"]},{"name":"Preform the hoop","process":"mold","text":"The tacky tube is bent around a metal form shaped like the racket head, and reinforcing pieces go on at stress points such as the throat bridge. Careless shaping leaves wrinkles once the tube is in the mold. A plastic piece in the handle end lets air into the bladder.","inputs":["plastic"]},{"name":"Inflate in a hot mold","process":"mold","text":"Inside the heated mold, compressed air blows up the bladder and pushes the layup against the walls. Resin turns so fluid that some leaks out, then it hardens.","inputs":[],"spec":"320 °F for 10 to 15 minutes"},{"name":"Sand off the resin","process":"grind","text":"Hot from the mold, the frame carries cured resin along its edges. Workers sand it until the frame is clean and smooth.","inputs":[]},{"name":"Drill the string holes","process":"machine","text":"The hoop is drilled for its string pattern, such as 16x19.","inputs":[]},{"name":"Paint the frame","process":"coat","text":"A production frame then gets paint and decals.","inputs":["paint"]},{"name":"Fit grommets and grip","process":"assemble","text":"Grommets line the holes so strings do not rub on sharp edges. A butt cap and a grip finish the handle.","inputs":["plastic","leather"]},{"name":"Weave in the strings","process":"weave","text":"Strings are threaded across and through the frame in a grid. Synthetic strings of nylon or other polymers have partly replaced natural gut, and a professional may have a racket restrung after every match.","inputs":["nylon"]}],"facts":["Despite the name, catgut strings have never been made from any part of a cat.","By changing only the fiber direction of its pieces, Head counts more than 420 billion possible layups for one racket.","Racket frames are stored as sheets in cold rooms, because the resin in them is already mixed and waiting to cure."],"where":[],"whereNote":null,"sources":[{"title":"How a Head racquet is made","url":"https://www.tennis-warehouse.com/learning_center/how_to/how_a_head_racquet_is_made.html"},{"title":"Racket (sports equipment)","url":"https://en.wikipedia.org/wiki/Tennis_racket"},{"title":"Method for manufacturing a sports racquet","url":"https://patents.google.com/patent/US7811500"},{"title":"Carbon fiber reinforced polymer","url":"https://en.wikipedia.org/wiki/Carbon_fiber_reinforced_polymer"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tequila","name":"Tequila","kind":"product","category":"drink","title":"How tequila is made","url":"https://assemblyline.org/make/tequila","stations":7,"upstream":25,"downstream":0,"depth":6,"dek":"A blue agave plant takes years to mature, and then workers cut off its leaves to leave a pineapple-shaped heart.","answer":"Tequila is made from the cooked heart of the blue agave plant. Harvesters called jimadores cut away the leaves, leaving the piña. Slow baking turns its starches into simple sugars, and the baked piñas are shredded and pressed to release the juice. That juice ferments, is distilled at least twice, and is bottled clear or aged in oak.","aka":["blue agave spirit","blanco tequila","reposado","añejo"],"inputs":["agave","yeast","water","lumber","glass-bottle"],"uses":[],"grounds":["agave","water","timber","silica-sand","limestone","sugarcane","sugar-beet","rock-salt","trona","natural-gas","air","corn","crude-oil"],"upstreamSlugs":["agave","yeast","water","lumber","glass-bottle","molasses","timber","silica-sand","soda-ash","limestone","polyethylene","sugarcane","sugar-beet","rock-salt","ammonia","carbon-dioxide","lime","trona","ethylene","natural-gas","air","corn","naphtha","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Trim the agave hearts","process":"harvest","text":"Jimadores check each plant for ripeness and cut away its leaves with a long-handled knife called a coa. What is left is the piña, a heavy core that looks like a giant pineapple.","inputs":["agave"]},{"name":"Bake them slowly","process":"bake","text":"The piñas are baked in ovens to break their complex starches down into simple sugars, mainly fructose. The slow cook also gives the sweet, caramelized flavor.","inputs":[]},{"name":"Shred and squeeze out juice","process":"crush","text":"Baked piñas are shredded or mashed under a heavy stone wheel called a tahona. Leftover fiber, the bagazo, is reused as compost, animal feed, fuel or paper.","inputs":[]},{"name":"Ferment in vats","process":"ferment","text":"The sweet juice goes into wooden or steel vats, with yeast added or left to arrive from the air. Mosto is the name for the weak alcoholic liquid that results.","inputs":["yeast","water"],"spec":"about 20 hours to 7 days"},{"name":"Distill it twice","process":"refine","text":"The first distillation yields ordinario. A second run gives clear silver tequila. By law at least two distillations are required.","inputs":[]},{"name":"Rest in white oak","process":"dry","text":"Blanco is bottled with little or no aging. Reposado rests in oak for at least two months and añejo for at least a year. Extra añejo ages at least three years.","inputs":["lumber"],"spec":"two months to three years"},{"name":"Dilute and bottle","process":"fill","text":"Water brings the spirit to a strength within the legal range, and it is bottled. Tequila must be between 35% and 55% alcohol by volume.","inputs":["water","glass-bottle"]}],"facts":["More than 300 million blue agave plants are harvested each year in the region around the town of Tequila.","Tequila is made only from blue agave, which sets it apart from other agave spirits such as mezcal.","Pulque, brewed from agave sap, is fermented but not distilled, and was made for thousands of years before tequila.","Every bottle carries a serial number, called a NOM, that identifies the distillery that made it."],"where":[],"whereNote":null,"sources":[{"title":"Tequila","url":"https://en.wikipedia.org/wiki/Tequila"},{"title":"Distilled beverage","url":"https://en.wikipedia.org/wiki/Distilled_beverage"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"timber","name":"Timber","kind":"raw","category":"farm","title":"How timber is grown and harvested","url":"https://assemblyline.org/make/timber","stations":5,"upstream":0,"downstream":282,"depth":0,"dek":"A log holding 150 board feet of wood weighs about a ton, so getting it out of the forest is the hard part.","answer":"Timber harvest starts with a road, because logs are too heavy to move far. Fallers with chain saws or tractor-mounted shears drop the trees, then limb them and buck the trunks into logs usually 16 to 48 feet long. A tractor drags each load to a landing, trucks carry it to the mill, and a scaler records its board feet.","aka":["logs","sawlogs","wood harvest","forestry"],"inputs":[],"uses":["silicon","skateboard","surfboard","guitar","electric-guitar","piano","violin","charcoal","wood-pellets","toothpick","chopsticks","popsicle-stick","wooden-spoon","wine-barrel","hardwood-floor","cricket-bat","incense","utility-pole","lumber","plywood","mdf","wood-pulp","baseball-bat"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["silicon","skateboard","surfboard","guitar","electric-guitar","piano","violin","charcoal","wood-pellets","toothpick","chopsticks","popsicle-stick","wooden-spoon","wine-barrel","hardwood-floor","cricket-bat","incense","utility-pole","lumber","plywood","mdf","wood-pulp","baseball-bat","silicone","polysilicon","magnesium","trichlorosilane","vodka","fireworks","wine","bourbon","scotch","cognac","port-wine","pencil","kitchen-knife","whiskey","rum","tequila","clothespin","laminate-floor","wooden-chair","door","sofa","ski","snowboard","chess-set","harmonica","ukulele","cello","drumstick","hammer","shovel","canoe","match","shipping-container","drum-kit","ceiling-fan","pinball-machine","loudspeaker","treadmill","nail-polish","kitchen-sponge","sanitary-pad","cellulose-acetate","paper","cardboard","toilet-paper","facial-tissue","rayon","diaper","shampoo","deodorant","syringe","condom","hearing-aid","solar-panel","contact-lens","airbag","cork-stopper","pressure-cooker","blender","foundation-makeup","eyeshadow","prosthetic-leg","double-glazed-window","remote-control","electric-toothbrush","silicon-wafer","steel","titanium","water-heater","toy-car","digital-camera","champagne","sunglasses","dice","shoelace","eyeglass-frame","soap","adhesive-bandage","aa-battery","vacuum-cleaner","drywall","popcorn","crayon","plastic-straw","paper-straw","paper-cup","paper-bag","pizza-box","egg-carton","wallpaper","board-game","jigsaw-puzzle","tampon","cotton-swab","vinyl-record","compact-disc","inkjet-printer","newspaper","book","envelope","sticky-notes","playing-cards","toothbrush","duct-tape","plastic-wrap","clear-tape","trading-cards","cake-mix","soda","energy-drink","hair-dye","cardboard-box","leather-shoe","satellite","car","electric-car","aluminum-window-frame","microchip","memory-chip","camera-sensor","solar-cell","lithium-ion-cell","ev-battery","television","hard-drive","wind-turbine","electric-motor","transformer","wristwatch","sheet-steel","tinplate","steel-wire","rebar","steel-beam","rail","scissors","steel-pipe","padlock","ball-bearing","car-engine","airplane","container-ship","locomotive","bicycle","motorcycle","elevator","rubiks-cube","dishwasher","office-chair","ice-skates","golf-club","fishing-rod","dumbbell","yo-yo","saxophone","dental-floss","wheelchair","barbed-wire","wrench","drill-bit","gas-cylinder","stained-glass","spark-plug","seat-belt","subway-train","leather-belt","suitcase","high-heels","usb-cable","pacemaker","hip-implant","jet-engine","candy-cane","toothpaste","detergent","plastic-bag","nitrile-glove","washing-machine","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","candle","salsa","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","thermometer","credit-card","smartphone","laptop","solid-state-drive","computer-keyboard","computer-mouse","drone","rocket","smartwatch","phone-charger","e-reader","graphics-card","refrigerator","microwave-oven","air-conditioner","safety-pin","hinge","saw-blade","fire-extinguisher","brake-pad","tin-can","canned-tuna","air-freshener","hairspray","wire-rope","nail","screw","needle","tire","ballpoint-pen","staple","dartboard","slinky","guitar-string","bolt","chain","coil-spring","chain-link-fence","suspension-bridge-cable","mattress","concrete","skyscraper","roller-skates","paint","condensed-milk","baby-formula","coconut-milk","canned-soup","sailboat","action-figure","power-outlet","mirror","golf-ball","water-bottle","tennis-racket","bowling-ball","billiard-ball","fashion-doll","snow-globe","neon-sign","toffee"],"steps":[{"name":"Manage stands, build roads","process":"grow","text":"The southeastern United States has large areas of intensively managed young forest, laced with landowners' roads. Elsewhere crews need access first. In mountains or poorly drained ground the road is a major cost, while flat, well-drained country may need only a bulldozed trail.","inputs":[]},{"name":"Fell the trees","process":"harvest","text":"Fallers cut with chain saws, and in small timber heavy tractor-mounted shears can sever a tree near the ground. A clearcut takes essentially every tree in a chosen block, while selective logging takes only the most valuable ones.","inputs":[]},{"name":"Limb and buck the stems","process":"cut","text":"Branches come off the main stem, which is then crosscut into logs. In cut-to-length logging a mechanical harvester does the felling, delimbing and bucking at the stump, leaving tops and limbs in the forest.","inputs":[],"spec":"logs usually 16 to 48 feet"},{"name":"Skid logs to the landing","process":"harvest","text":"A cable or chain goes on one end of the log, and a tractor or other machine drags it to a landing that trucks can reach. Terrain, tree size and distance decide which system works best. Skidders and forwarders do this work in mechanized operations.","inputs":[]},{"name":"Truck and scale the logs","process":"inspect","text":"Trucks usually run straight to the mill's log pond or storage deck. Somewhere on the way a scaler measures each log's length and small-end diameter and reads off its board feet. At the mill, low-grade logs may go to pulp and high-grade ones to veneer.","inputs":[]}],"facts":["In 2008 the US logging industry's fatality rate was over 30 times higher than the rate for all workers.","Tree-length logging leaves the branches and nutrients in the cut area, while whole-tree logging drags trees to the roadside with their limbs still on."],"where":[],"whereNote":null,"sources":[{"title":"Logging","url":"https://en.wikipedia.org/wiki/Logging"},{"title":"Exploitation (Logging), IRS Timber Industry Audit Manual","url":"https://timbertax.org/publications/irs/auditmanual/chapter100/125"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tin","name":"Tin","kind":"material","category":"metals","title":"How tin is made","url":"https://assemblyline.org/make/tin","stations":5,"upstream":3,"downstream":138,"depth":2,"dek":"Bend a bar of tin by hand and you can hear it crackle, a sound called tin cry.","answer":"Tin comes from cassiterite, a heavy tin oxide, and about 80 percent of it is recovered from sand and gravel deposits downstream of the original rock. Dredges and washing plants separate the heavy grains. Furnaces then reduce the oxide with carbon or coke to molten tin, which is cast into ingots.","aka":["tin metal","pure tin"],"inputs":["tin-ore","coke"],"uses":["microchip","tinplate","brass","bronze","solder","padlock","window-glass","indium-tin-oxide","medal","bell","usb-cable"],"grounds":["tin-ore","coal"],"upstreamSlugs":["tin-ore","coke","coal"],"downstreamSlugs":["microchip","tinplate","brass","bronze","solder","padlock","window-glass","indium-tin-oxide","medal","bell","usb-cable","hearing-aid","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","rocket","smartwatch","wireless-earbuds","phone-charger","digital-camera","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","tin-can","canned-tuna","air-freshener","hairspray","aa-battery","wristwatch","faucet","tire","electric-guitar","trumpet","ballpoint-pen","pencil-eraser","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","light-switch","power-outlet","leather-belt","handbag","flag","zipper","drum-kit","bronze-statue","printed-circuit-board","led-bulb","solar-panel","refrigerator","air-conditioner","flute","stained-glass","smoke-detector","eyeglass-frame","microphone","mirror","skyscraper","windshield","double-glazed-window","lcd-screen","oled-screen","car","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","bicycle","motorcycle","down-jacket","raincoat","backpack","suitcase","jeans","ev-battery","hard-drive","wind-turbine","microwave-oven","washing-machine","airplane","locomotive","elevator","blender","ceiling-fan","treadmill","pinball-machine","aluminum-window-frame","electric-kettle","pencil","scissors","container-ship","shipping-container","golf-ball","wallpaper","wooden-chair","water-bottle","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","neon-sign","suspension-bridge-cable","brake-pad","subway-train","toffee"],"steps":[{"name":"Dredge the tin sands","process":"mine","text":"Cassiterite is hard, heavy and chemically tough, so it washes out of eroded rock and settles in river valleys and under the sea. Dredging, hydraulicking and open pits are the cheapest ways to dig it.","inputs":["tin-ore"]},{"name":"Crush hard-rock ore","process":"crush","text":"Ore from the original veins is broken up so that the grains of tin oxide are freed from the rock around them.","inputs":[]},{"name":"Sort the heavy grains","process":"separate","text":"Tin dioxide has a high specific gravity. Washing lets the heavy grains sink while lighter waste is carried away, leaving a concentrate rich in cassiterite.","inputs":[]},{"name":"Reduce it with carbon","process":"melt","text":"Carbon or coke heats the concentrate in a reverberatory or electric furnace. Carbon takes the oxygen from the tin oxide and leaves liquid tin.","inputs":["coke"]},{"name":"Cast into ingots","process":"cast","text":"Molten tin is poured into molds. It melts at only about 232 °C, which is the reason it is so easy to alloy and to cast.","inputs":[]}],"facts":["Just under half of the world's tin was used in solder in 2018.","Below 13.2 °C, white tin can slowly turn into a brittle gray form.","The United States has not mined tin since 1993, yet it recycled nearly 14,000 tonnes in 2006."],"where":[{"place":"China","share":"110,000 tonnes"},{"place":"Indonesia","share":"51,000 tonnes"},{"place":"Peru","share":"34,600 tonnes"},{"place":"Bolivia","share":"20,700 tonnes"},{"place":"Brazil","share":"12,000 tonnes"}],"whereNote":"2011, tonnes of tin mined.","sources":[{"title":"Tin","url":"https://en.wikipedia.org/wiki/Tin"},{"title":"Tin plate","url":"https://en.wikipedia.org/wiki/Tin_plate"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tin-can","name":"Tin can","kind":"product","category":"hardware","title":"How tin cans are made","url":"https://assemblyline.org/make/tin-can","stations":9,"upstream":59,"downstream":52,"depth":8,"dek":"A can's welded side seam overlaps by just 0.3 to 0.5 mm, and rollers forge the two edges together.","answer":"A classic three-piece tin can is built from tinplate, which is steel sheet coated with tin. Coated sheets are cut to size, rolled into cylinders and welded down the side, and the seam is coated again. Beads stiffen the body, and a separate bottom is locked on by a double seam. The top goes on after filling.","aka":["steel can","food can","canned food can"],"inputs":["tinplate","lacquer","ink"],"uses":["paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup"],"grounds":["water","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","limestone","dolomite","manganese-ore","natural-gas","coal","rock-salt","quartz","timber","sugar-beet"],"upstreamSlugs":["tinplate","lacquer","ink","steel","tin","ethanol","acrylic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","tin-ore","coke","corn","sugarcane","yeast","ethylene","propylene","ammonia","sulfuric-acid","methanol","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","iron-ore","sulfur","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","coal","molasses","naphtha","hydrogen","benzene","rock-salt","quartz","charcoal","timber","sugar-beet","toluene"],"downstreamSlugs":["paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","scissors","mirror","car","electric-car","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","golf-ball","wallpaper","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","padlock"],"steps":[{"name":"Shear the coil into sheets","process":"cut","text":"Coils of tinplate are sheared into flat plates. Tinplate is steel with a very thin layer of tin on both faces.","inputs":["tinplate"]},{"name":"Coat and print the sheets","process":"coat","text":"While still flat, the plates are coated to keep the contents off the metal, and printed if the can will carry a design.","inputs":["lacquer","ink"]},{"name":"Slit into body blanks","process":"cut","text":"The plates are cut into strips and then rectangles, one for each can body.","inputs":[]},{"name":"Roll and weld the seam","process":"weld","text":"Each rectangle is rolled into a cylinder. Rollers squeeze a tiny overlap while current heats the metal to just below melting, which forges the edges together. Early cans were soldered with a tin-lead alloy, which could cause lead poisoning.","inputs":[],"spec":"0.3–0.5 mm overlap"},{"name":"Repair the seam coating","process":"coat","text":"Welding exposes bare iron and tin along the join, so the seam gets its own protective stripe of coating.","inputs":["lacquer"]},{"name":"Bead the body","process":"press","text":"Rollers press ribs into the wall, which stiffen a food can against the pressure and vacuum of processing.","inputs":[]},{"name":"Flange the ends","process":"press","text":"Rollers bend the rim of the cylinder outward so a separate end can be joined to it.","inputs":[]},{"name":"Fold the bottom on","process":"assemble","text":"A stamped disc is placed on the base. The edges of disc and body are curled together in a double seam, which locks them without any adhesive.","inputs":[]},{"name":"Inspect and stack","process":"inspect","text":"Empty cans are checked and stacked on pallets. The top is seamed on after the food goes in.","inputs":[]}],"facts":["The Dutch Navy reportedly carried salmon in tin-plated iron boxes as early as 1772.","Peter Durand obtained an English patent in 1810 for storing food in tin-coated iron cans for Frenchman Philippe de Girard.","When the American Can Company was founded in 1901, it was producing 90% of the tin cans in the United States."],"where":[],"whereNote":null,"sources":[{"title":"Tin can","url":"https://en.wikipedia.org/wiki/Tin_can"},{"title":"Tinplate","url":"https://en.wikipedia.org/wiki/Tinplate"},{"title":"Steel and tin cans","url":"https://en.wikipedia.org/wiki/Steel_and_tin_cans"},{"title":"Metal Packaging Can Manufacturing Process","url":"https://www.ctcanmachine.com/news/metal-packaging-can-manufacturing-process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tin-ore","name":"Tin ore","kind":"raw","category":"ground","title":"How tin ore is mined","url":"https://assemblyline.org/make/tin-ore","stations":5,"upstream":0,"downstream":139,"depth":0,"dek":"Even rich tin fields are so lean that one kilogram of cassiterite can mean digging up to eight tons of ore.","answer":"Water does most of the work in tin mining, because cassiterite is far heavier than the sand around it. Jets blast old riverbeds into slurry that runs down sluice boxes, or floating dredges dig flooded fields and sort the ore on board with jigs and shaking tables. Vein deposits in places like Bolivia are mined underground and need froth flotation.","aka":["cassiterite"],"inputs":[],"uses":["tin"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["tin","microchip","tinplate","brass","bronze","solder","padlock","window-glass","indium-tin-oxide","medal","bell","usb-cable","hearing-aid","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","rocket","smartwatch","wireless-earbuds","phone-charger","digital-camera","game-console","wifi-router","e-reader","inkjet-printer","graphics-card","remote-control","electric-toothbrush","tin-can","canned-tuna","air-freshener","hairspray","aa-battery","wristwatch","faucet","tire","electric-guitar","trumpet","ballpoint-pen","pencil-eraser","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","hinge","key","fire-extinguisher","gas-cylinder","light-switch","power-outlet","leather-belt","handbag","flag","zipper","drum-kit","bronze-statue","printed-circuit-board","led-bulb","solar-panel","refrigerator","air-conditioner","flute","stained-glass","smoke-detector","eyeglass-frame","microphone","mirror","skyscraper","windshield","double-glazed-window","lcd-screen","oled-screen","car","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","bicycle","motorcycle","down-jacket","raincoat","backpack","suitcase","jeans","ev-battery","hard-drive","wind-turbine","microwave-oven","washing-machine","airplane","locomotive","elevator","blender","ceiling-fan","treadmill","pinball-machine","aluminum-window-frame","electric-kettle","pencil","scissors","container-ship","shipping-container","golf-ball","wallpaper","wooden-chair","water-bottle","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","neon-sign","suspension-bridge-cable","brake-pad","subway-train","toffee"],"steps":[{"name":"Jet the old riverbed","process":"mine","text":"Draglines or shovels remove the barren overburden. High-pressure water jets then break up the tin-bearing sand, and a submerged gravel pump lifts the muddy slurry. A large share of the world's tin ore is mined this way.","inputs":[]},{"name":"Run the sluice boxes","process":"separate","text":"Slurry flows down sloping boxes with baffles set along their length. Heavy cassiterite drops to the bottom while lighter waste spills over the end to the tailings dump. Every so often the flow stops so crews can take out the crude concentrate.","inputs":[]},{"name":"Float a bucket dredge","process":"mine","text":"Where water is plentiful, the field is flooded and a dredge floats on it, sometimes offshore on the seabed as in Indonesia and Thailand. An endless bucket chain feeds a plant on board, where jigs and shaking tables sort by weight, and waste leaves over the stern.","inputs":[]},{"name":"Tunnel the granite veins","process":"mine","text":"Vein deposits in granite are worked by ordinary hard-rock methods. Deep mines place their first crushers underground, reducing the rock to a manageable size before it travels to the surface.","inputs":[]},{"name":"Float the complex ores","process":"separate","text":"Sulfide-rich vein ore resists simple gravity methods and usually needs froth flotation. Bolivian concentrate may reach only 50 to 60% tin, against 70 to 75% from the alluvial fields of Southeast Asia.","inputs":[]}],"facts":["Cassiterite is the only commercially important tin ore.","Cornwall and Devon in England have 4500 year old tin workings, in hot quartz veins cooked into the rock around granite.","Alluvial or secondary deposits yield about 80% of all tin, far from the rock where it first formed."],"where":[{"place":"China","share":"110,000 t"},{"place":"Indonesia","share":"51,000 t"},{"place":"Peru","share":"34,600 t"},{"place":"Bolivia","share":"20,700 t"},{"place":"Brazil","share":"12,000 t"}],"whereNote":"Tin mined in 2011, out of about 253,000 tonnes worldwide; the Wikipedia article gives no newer ranking.","sources":[{"title":"Tin processing: Mining and concentrating","url":"https://www.britannica.com/technology/tin-processing/Mining-and-concentrating"},{"title":"Tin processing","url":"https://www.britannica.com/technology/tin-processing"},{"title":"Tin","url":"https://en.wikipedia.org/wiki/Tin"},{"title":"Cassiterite","url":"https://en.wikipedia.org/wiki/Cassiterite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tinplate","name":"Tinplate","kind":"material","category":"metals","title":"How tinplate is made","url":"https://assemblyline.org/make/tinplate","stations":6,"upstream":27,"downstream":56,"depth":5,"dek":"A tin can is steel wearing a thin coat of tin, plated onto a strip moving along a line.","answer":"Tinplate is thin steel sheet with a coating of tin that keeps it from rusting. The steel is rolled into a thin strip, pickled in acid to remove scale, rolled again cold, annealed, and then plated with tin, now usually by electric current. The strip is then cut into sheets or coiled for can makers.","aka":["tin-coated steel","tin plate","can stock"],"inputs":["steel","tin"],"uses":["tin-can","canned-tuna","air-freshener","hairspray"],"grounds":["tin-ore","iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","coal","quartz","timber","crude-oil","sulfur"],"upstreamSlugs":["steel","tin","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","tin-ore","coke","iron-ore","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","coal","quartz","charcoal","timber","crude-oil","sulfur"],"downstreamSlugs":["tin-can","canned-tuna","air-freshener","hairspray","paint","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","scissors","mirror","car","electric-car","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","golf-ball","wallpaper","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","padlock"],"steps":[{"name":"Roll the steel thin","process":"roll","text":"Low-carbon steel is rolled in a strip mill into a long band. Early hot strip mills could not make strip suitable for tinplate, so the thin gauge came later from cold rolling.","inputs":["steel"]},{"name":"Pickle away the oxide","process":"wash","text":"The strip runs through acid to remove mill scale. Tin only sticks properly to bare, clean steel.","inputs":[]},{"name":"Cold-roll it again","process":"roll","text":"From 1929, cold rolling was used to reduce the strip to its final thin gauge. The surface comes out smooth and bright, which makes a good base for plating.","inputs":[]},{"name":"Anneal to soften it","process":"heat-treat","text":"Cold rolling hardens the steel, so it is heated again to make it soft enough to be drawn and folded into a can. Older pack mills annealed plates for 10 to 14 hours.","inputs":[]},{"name":"Plate it with tin","process":"coat","text":"The strip is covered with a thin layer of tin. Old mills dipped plates in pots of molten tin under a flux. Modern lines use continuous electrolytic tinning, where electric current builds the tin layer on the moving strip.","inputs":["tin"]},{"name":"Cut or coil it","process":"cut","text":"At the end of the line the strip is cut with a guillotine shear into sheets or wound into a coil and sent to a can maker.","inputs":[]}],"facts":["The first strip mill for tinplate was built at Ashland, Kentucky, in 1923.","Old trade sheets measured 20 by 14 inches and were packed 112 to a box that weighed about 51 kilograms."],"where":[],"whereNote":null,"sources":[{"title":"Tin plate","url":"https://en.wikipedia.org/wiki/Tin_plate"},{"title":"Steelmaking","url":"https://en.wikipedia.org/wiki/Steelmaking"},{"title":"Cold rolling","url":"https://en.wikipedia.org/wiki/Cold_rolling"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tire","name":"Tire","kind":"product","category":"machines","title":"How tires are made","url":"https://assemblyline.org/make/tire","stations":8,"upstream":63,"downstream":4,"depth":7,"dek":"A tire is a cake of rubber, steel cord and fabric, assembled flat and then pressed into its tread in a hot mold.","answer":"A car tire starts as batches of synthetic and natural rubber blended with carbon black. Separate machines make the tread, the fabric plies and the steel bead rings. A builder wraps them around a drum into a soft, shapeless tire. A hot mold then presses in the tread pattern while the rubber cures into a springy solid.","aka":["car tyre","pneumatic tire","radial tire"],"inputs":["synthetic-rubber","natural-latex","carbon-black","sulfur","steel-wire","brass","nylon","polyester"],"uses":["car","electric-car","bicycle","motorcycle"],"grounds":["natural-latex","sulfur","water","crude-oil","air","natural-gas","copper-ore","zinc-ore","lead-ore","tin-ore","coal","iron-ore","limestone","dolomite","manganese-ore","bauxite","quartz","timber","rock-salt","corn","sugarcane","sugar-beet"],"upstreamSlugs":["synthetic-rubber","natural-latex","carbon-black","sulfur","steel-wire","brass","nylon","polyester","naphtha","benzene","ethylene","styrene","water","crude-oil","air","steel","copper","zinc","lead","tin","aluminum","nitric-acid","ammonia","pet-plastic","hydrogen","toluene","natural-gas","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","copper-ore","sulfuric-acid","zinc-ore","lead-ore","coke","tin-ore","coal","petroleum-coke","alumina","p-xylene","ethylene-glycol","iron-ore","limestone","dolomite","silicon","propane","manganese-ore","bauxite","caustic-soda","carbon-dioxide","quartz","charcoal","timber","rock-salt","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["car","electric-car","bicycle","motorcycle"],"steps":[{"name":"Blend the rubber compounds","process":"knead","text":"Rubber is worked together with carbon black, silica and other chemicals until the batch is uniform. The most common rubber is a styrene-butadiene copolymer, and each part of the tire gets its own recipe, from a grippy tread to a flexible sidewall.","inputs":["synthetic-rubber","natural-latex","carbon-black","sulfur"]},{"name":"Wrap the bead wire","process":"assemble","text":"Steel cables are bundled into rings and sheathed in hard rubber. These rings are the beads. They grip the wheel rim and keep the air from escaping where tire meets metal.","inputs":["steel-wire"]},{"name":"Brass-coat the steel cords","process":"coat","text":"Steel cords get a thin layer of brass, which helps rubber stick to them. Rubber that lets go of its cords is a tire that comes apart.","inputs":["steel-wire","brass"]},{"name":"Press cords into rubber sheets","process":"roll","text":"Rollers squeeze rubber on both sides of rows of parallel cords, making wide sheets called plies. In a radial tire the cords run straight across from bead to bead. Further steel-reinforced belts sit under the tread to stabilize it.","inputs":["nylon","polyester"]},{"name":"Squeeze out the tread","process":"extrude","text":"Warm tread rubber is pushed through a shaped die in one long ribbon, then cut to the length of one tire's circumference.","inputs":[]},{"name":"Build the raw tire","process":"assemble","text":"A building drum collects the inner liner, plies, beads, belts, sidewalls and tread in order. The result is a soft, tacky tire, with no tread pattern yet, that holds together only by stickiness.","inputs":[]},{"name":"Cure it in a hot mold","process":"mold","text":"The raw tire goes into a heated mold that presses the tread grooves and the sidewall lettering into the rubber. Heat sets off vulcanization, and the sticky rubber becomes elastic and durable.","inputs":[]},{"name":"Trim, test and inspect","process":"inspect","text":"Vent spurs are trimmed off and every tire is checked by eye and by machine. Samples face harder tests for uniformity and strength.","inputs":[]}],"facts":["The LEGO Group made over 318 million toy tires in 2011, which Guinness World Records recognized as the highest annual tire production by any manufacturer.","A passenger vehicle uses roughly 5 to 15 percent of its fuel just overcoming rolling resistance in its tires.","John Boyd Dunlop built the first practical pneumatic tire in 1888, partly to ease the headaches his 10-year-old son Johnnie suffered while riding."],"where":[],"whereNote":null,"sources":[{"title":"Tire","url":"https://en.wikipedia.org/wiki/Tire"},{"title":"Vulcanization","url":"https://en.wikipedia.org/wiki/Vulcanization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"titanium","name":"Titanium","kind":"material","category":"metals","title":"How titanium is made","url":"https://assemblyline.org/make/titanium","stations":5,"upstream":16,"downstream":6,"depth":4,"dek":"You cannot smelt titanium like iron, because it grabs carbon and oxygen so eagerly that the usual route ruins it.","answer":"Titanium ore is turned into titanium tetrachloride, a liquid, by passing chlorine over a hot mixture of ore and carbon. After distilling it clean, makers reduce it with molten magnesium in argon at about 800 °C in the Kroll process. The porous sponge of metal is then melted under vacuum or inert gas and worked into mill products.","aka":["titanium metal","titanium sponge","Kroll process"],"inputs":["titanium-ore","chlorine","magnesium","argon"],"uses":["pacemaker","hip-implant","airplane","jet-engine","prosthetic-leg","drill-bit"],"grounds":["titanium-ore","rock-salt","water","dolomite","air","sulfur","quartz","coal","timber"],"upstreamSlugs":["titanium-ore","chlorine","magnesium","argon","rock-salt","water","sulfuric-acid","dolomite","silicon","air","sulfur","quartz","coke","coal","charcoal","timber"],"downstreamSlugs":["pacemaker","hip-implant","airplane","jet-engine","prosthetic-leg","drill-bit"],"steps":[{"name":"Chlorinate the ore","process":"react","text":"Chlorine gas is passed over a red-hot mix of rutile or ilmenite and carbon. The titanium comes out combined with chlorine as titanium tetrachloride, a colorless volatile liquid. Heating the ore with carbon alone would produce titanium carbide.","inputs":["titanium-ore","chlorine"]},{"name":"Distill it clean","process":"refine","text":"The crude tetrachloride is purified by fractional distillation. It reacts readily with trace water, so everything downstream must be kept dry.","inputs":[]},{"name":"Reduce it with magnesium","process":"react","text":"In the Kroll process, the purified liquid meets molten magnesium in a reactor filled with argon. The magnesium takes the chlorine, and titanium is left behind as a porous sponge. It is a batch process, which is why titanium stays so costly.","inputs":["magnesium","argon"],"spec":"about 800 °C"},{"name":"Melt the sponge into ingot","process":"melt","text":"Titanium burns in normal air at temperatures below its melting point of 1,668 °C, so melting must be done in a vacuum or inert atmosphere. Sponge, sometimes with a master alloy, is melted into an ingot.","inputs":[]},{"name":"Forge into mill products","process":"forge","text":"The ingot is turned into billet, bar, plate, sheet, strip and tube. Heating titanium in air during forging can leave a brittle, oxygen-rich skin, so shops take care with the atmosphere.","inputs":[]}],"facts":["Titanium forms a protective oxide skin 1 to 2 nanometers thick as soon as it meets air.","William Gregor discovered titanium in 1791 in black sand from a stream in Cornwall.","The Kroll process also drives most of the world's production of magnesium metal."],"where":[{"place":"China","share":"69% of titanium sponge"},{"place":"Japan","share":"17% of titanium sponge"}],"whereNote":"2024, titanium sponge production per the USGS.","sources":[{"title":"Titanium","url":"https://en.wikipedia.org/wiki/Titanium"},{"title":"Kroll process","url":"https://en.wikipedia.org/wiki/Kroll_process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"titanium-dioxide","name":"Titanium dioxide","kind":"material","category":"chemicals","title":"How titanium dioxide is made","url":"https://assemblyline.org/make/titanium-dioxide","stations":6,"upstream":10,"downstream":184,"depth":3,"dek":"Titanium dioxide is the white in paint, sunscreen, paper and food coloring, and the plant that makes it recycles its own chlorine.","answer":"Titanium dioxide is made from the mineral ilmenite or from rutile sand. In the chloride route, the ore is converted with chlorine and carbon into a liquid titanium chloride, distilled clean, and burned with oxygen to make fine white particles. The sulfate route dissolves the ore in sulfuric acid instead. The powder is then coated and milled.","aka":["titanium white","TiO2","pigment white 6"],"inputs":["titanium-ore","chlorine","coke","oxygen","sulfuric-acid"],"uses":["toothpaste","sunscreen","lipstick","nail-polish","ink","paint","crayon","pencil-eraser","candy-coated-chocolate","foundation-makeup","pvc-pipe","e-reader","pigment"],"grounds":["titanium-ore","rock-salt","water","coal","air","sulfur"],"upstreamSlugs":["titanium-ore","chlorine","coke","oxygen","sulfuric-acid","rock-salt","water","coal","air","sulfur"],"downstreamSlugs":["toothpaste","sunscreen","lipstick","nail-polish","ink","paint","crayon","pencil-eraser","candy-coated-chocolate","foundation-makeup","pvc-pipe","e-reader","pigment","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","scissors","mirror","car","electric-car","airplane","container-ship","shipping-container","locomotive","bicycle","motorcycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toothbrush","mascara","pvc","abs-plastic","lego-brick","lcd-screen","porcelain","chalk","candy-cane","sprinkles","plastic-straw","printer-toner","eyeshadow","towel","vacuum-cleaner","cotton-candy","pillow","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","soap","detergent","nitrile-glove","paperclip","donut","corn-flakes","popcorn","fireworks","candle","salsa","fish-sticks","zip-bag","blender","dishwasher","cotton-swab","mouthwash","cough-syrup","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","padlock","plastic-wrap","garden-hose","football","volleyball","yoga-mat","inflatable-pool-toy","chain-link-fence","power-cable","usb-cable","hearing-aid","thermometer","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","harmonica","suitcase","high-heels","phone-charger","graphics-card","electric-toothbrush","smartwatch","digital-camera","toffee","aa-battery"],"steps":[{"name":"Separate the ore","process":"separate","text":"Beach sands and rock deposits are concentrated to separate titanium minerals from sand and other heavy minerals. Ilmenite is the main ore.","inputs":["titanium-ore"]},{"name":"Chlorinate it with carbon","process":"react","text":"In the chloride route, the ore is reacted with chlorine and carbon, which leaves titanium tetrachloride, a volatile liquid. Iron and other impurities stay behind as solids or other chlorides.","inputs":["chlorine","coke"]},{"name":"Distill the liquid clean","process":"refine","text":"The tetrachloride is distilled until it is very pure. Any color-giving trace metals that remain would show up in the finished white.","inputs":[]},{"name":"Burn it with oxygen","process":"react","text":"The purified liquid is reacted with oxygen in a flame, which regenerates the chlorine and produces titanium dioxide. The chlorine is sent back to the first reactor.","inputs":["oxygen"]},{"name":"Or dissolve it in sulfuric acid","process":"react","text":"In the sulfate route, ilmenite is dissolved in sulfuric acid and iron sulfate is crystallized and removed. The titanium solution is then precipitated and heated to make pigment.","inputs":["sulfuric-acid"]},{"name":"Coat and mill the pigment","process":"coat","text":"Particles are coated with a thin layer of other oxides and milled to the right size for paint, plastic or paper. Size controls how much light the pigment scatters.","inputs":[]}],"facts":["In the chloride route the chlorine used on the ore is released again when the liquid is burned, and it goes back to the first reactor.","It has been estimated that titanium dioxide is used in two-thirds of all pigments.","The sulfate process runs in batches, while the chloride process runs continuously."],"where":[],"whereNote":null,"sources":[{"title":"Titanium dioxide","url":"https://en.wikipedia.org/wiki/Titanium_dioxide"},{"title":"Pigment","url":"https://en.wikipedia.org/wiki/Pigment"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"titanium-ore","name":"Titanium ore","kind":"raw","category":"ground","title":"How titanium ore is mined","url":"https://assemblyline.org/make/titanium-ore","stations":5,"upstream":0,"downstream":191,"depth":0,"dek":"One floating dredge can suck up 7,000 tons of dune sand an hour, and a floating plant behind it keeps the heavy grains.","answer":"Titanium ore is often mined by a boat in a pond it digs for itself. A floating dredge cuts into mineral-rich sand and pumps it to a plant where screens and gravity spirals keep the heavy grains and return the rest. Magnets and electric fields then split that dark concentrate into ilmenite, rutile, zircon and monazite, with no chemicals at some operations.","aka":["ilmenite","rutile"],"inputs":[],"uses":["titanium-dioxide","titanium"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["titanium-dioxide","titanium","toothpaste","sunscreen","lipstick","nail-polish","ink","paint","crayon","pencil-eraser","candy-coated-chocolate","foundation-makeup","pvc-pipe","e-reader","pigment","pacemaker","hip-implant","airplane","jet-engine","prosthetic-leg","drill-bit","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","refrigerator","microwave-oven","washing-machine","electric-kettle","pencil","scissors","mirror","car","electric-car","container-ship","shipping-container","locomotive","bicycle","motorcycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","snow-globe","toy-car","coil-spring","hammer","wheelbarrow","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toothbrush","mascara","pvc","abs-plastic","lego-brick","lcd-screen","porcelain","chalk","candy-cane","sprinkles","plastic-straw","printer-toner","eyeshadow","towel","vacuum-cleaner","cotton-candy","pillow","condensed-milk","baby-formula","coconut-milk","canned-meat","canned-soup","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","soap","detergent","nitrile-glove","paperclip","donut","corn-flakes","popcorn","fireworks","candle","salsa","fish-sticks","zip-bag","blender","dishwasher","cotton-swab","mouthwash","cough-syrup","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","padlock","plastic-wrap","garden-hose","football","volleyball","yoga-mat","inflatable-pool-toy","chain-link-fence","power-cable","usb-cable","hearing-aid","thermometer","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","harmonica","suitcase","high-heels","phone-charger","graphics-card","electric-toothbrush","smartwatch","digital-camera","toffee","aa-battery"],"steps":[{"name":"Dredge the sand","process":"mine","text":"A dredge floats on an artificial pond and cuts into the ore at its edge or base, so the sand slumps in and gets pumped away. Eramet's dredge in Senegal is 50 m long and advances along the dunes. Dry mining units reach pockets a dredge cannot.","inputs":[]},{"name":"Screen off the oversize","process":"separate","text":"Rotating screens called trommels throw out oversize material. The rest moves on as a slurry to the concentrator.","inputs":[]},{"name":"Spin out the heavies","process":"separate","text":"Spiral chutes sort the slurry by gravity, leaving a concentrate of heavy minerals. Deposits usually hold just 3 to 12% of these, so most of the sand goes back to the pond as tailings for rebuilding the land.","inputs":[]},{"name":"Pull with magnets","process":"separate","text":"At a separate plant, magnetic separators divide the concentrate. The magnetic share is dried and treated further to make ilmenite products, while the rest goes through wet gravity circuits that remove silica and trash minerals.","inputs":[]},{"name":"Split by static charge","process":"separate","text":"Electrostatic separators exploit a difference in conductivity: rutile conducts, while zircon and monazite do not. Finished minerals go to warehouses and then to ships.","inputs":[]}],"facts":["Ilmenite is the main source of titanium dioxide, the white pigment used in paint, sunscreen and paper.","Rutile ranks among the known crystals with the highest refractive index, which gives it a diamond-like sparkle.","Kenmare's Moma operation moves almost 40 million tonnes of titanium-rich sand a year, mostly by dredge."],"where":[],"whereNote":null,"sources":[{"title":"Moma's operating process (Kenmare Resources)","url":"https://www.kenmareresources.com/our-business/the-moma-mine/momas-operating-process/"},{"title":"Production (Eramet Grande Cote)","url":"https://grande-cote.eramet.com/en/?p=52087"},{"title":"Titanium processing","url":"https://www.britannica.com/technology/titanium-processing"},{"title":"Ilmenite","url":"https://en.wikipedia.org/wiki/Ilmenite"},{"title":"Rutile","url":"https://en.wikipedia.org/wiki/Rutile"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"toaster","name":"Toaster","kind":"product","category":"machines","title":"How toasters are made","url":"https://assemblyline.org/make/toaster","stations":6,"upstream":40,"downstream":0,"depth":7,"dek":"Nichrome, the alloy in a toaster's glowing wires, survives being red hot again and again.","answer":"A press punches a sheet of aluminum and forces it into a die to form a hollow toaster-shaped shell. A machine wraps nichrome wire around sheets of mica, and two of them are bolted to the base on either side of the spring-loaded bread tray. A temperature sensor and a terminal board are fitted, and the shell goes over the base.","aka":["electric toaster","pop-up toaster"],"inputs":["aluminum","nickel","chromium","mica","nichrome","plastic","copper-wire"],"uses":[],"grounds":["mica","crude-oil","coal","nickel-ore","chromite","limestone","air","water","natural-gas","bauxite","sulfur","rock-salt","trona","copper-ore","corn","sugarcane","sugar-beet"],"upstreamSlugs":["aluminum","nickel","chromium","mica","nichrome","plastic","copper-wire","crude-oil","coal","petroleum-coke","alumina","nickel-ore","sulfuric-acid","chromite","coke","soda-ash","limestone","air","water","naphtha","natural-gas","ethylene","propylene","copper","bauxite","caustic-soda","lime","sulfur","rock-salt","ammonia","carbon-dioxide","trona","hydrogen","copper-ore","oxygen","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Punch the metal shell","process":"stamp","text":"A press cuts out a sheet of aluminum. A second press forces a punch into it inside a toaster-shaped die, and the metal flows backward around the punch into a hollow shell.","inputs":["aluminum"]},{"name":"Wind the heating wire","process":"assemble","text":"Nichrome wire, an alloy of nickel and chromium, is loaded into a machine that wraps it around a thin sheet of mica. Mica does not conduct electricity, and it keeps the wire in place.","inputs":["nickel","chromium","mica","nichrome"]},{"name":"Bolt in the elements","process":"assemble","text":"Two wrapped mica sheets are bolted to the toaster base, and a spring-loaded tray is set between them.","inputs":[]},{"name":"Fit the sensor and timer","process":"assemble","text":"A bimetallic strip is mounted on pivoting brackets with a spring and a release. Heat bends the strip until the release trips and cuts the power.","inputs":[]},{"name":"Wire the terminal board","process":"assemble","text":"Two sheet-metal conductors are layered around an insulating sheet to make a terminal board, which is screwed to the rack. The cord is threaded through the molded plastic base.","inputs":["plastic","copper-wire"]},{"name":"Fit the shell and test","process":"inspect","text":"The shell is fitted over the base. Toasters are tested on the line for browning, shut-off temperature and total toasting time.","inputs":[]}],"facts":["Albert Marsh created nichrome, an alloy of nickel and chromium, in 1905, and it solved the heating element problem that had held electric toasters back.","The earliest electric toasters had no temperature control, and the bread had to be turned by hand.","By the end of the 1940s, Sunbeam had a sensor that switched the heater off when the bread itself reached 310 degrees Fahrenheit."],"where":[],"whereNote":null,"sources":[{"title":"Toaster","url":"https://www.encyclopedia.com/manufacturing/news-wires-white-papers-and-books/toaster"},{"title":"Toaster","url":"https://en.wikipedia.org/wiki/Toaster"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"toffee","name":"Toffee","kind":"product","category":"food","title":"How toffee is made","url":"https://assemblyline.org/make/toffee","stations":9,"upstream":70,"downstream":0,"depth":10,"dek":"Toffee is cooked to the hard crack stage, hot enough that a drop snaps like glass when it cools.","answer":"A typical factory toffee starts as sucrose, glucose, butter, palm oil and sweetened condensed milk dissolved in water. Cooking drives off the surplus water, and the batch is held hot until it caramelizes. From there it either cools to a plastic state, gets shaped into a rope, cut and wrapped, or goes straight into molds from a depositor.","aka":["English toffee","butter crunch"],"inputs":["sugar","butter","palm-oil","condensed-milk","almonds"],"uses":[],"grounds":["almonds","sugarcane","sugar-beet","water","raw-milk","oil-palm-fruit","limestone","rock-salt","seawater","tin-ore","corn","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","dolomite","manganese-ore","natural-gas","coal","quartz","timber"],"upstreamSlugs":["sugar","butter","palm-oil","condensed-milk","almonds","sugarcane","sugar-beet","water","lime","raw-milk","cream","table-salt","oil-palm-fruit","tin-can","limestone","rock-salt","seawater","tinplate","lacquer","ink","steel","tin","ethanol","acrylic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","pig-iron","magnesium","steel-scrap","oxygen","manganese","argon","tin-ore","coke","corn","yeast","ethylene","propylene","ammonia","sulfuric-acid","methanol","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","iron-ore","sulfur","dolomite","silicon","propane","manganese-ore","natural-gas","coal","molasses","naphtha","hydrogen","benzene","quartz","charcoal","timber","toluene"],"downstreamSlugs":[],"steps":[{"name":"Mix a slurry","process":"mix","text":"Automatic weighing tanks combine sugars, milk and fats with water into a consistent slurry. Batches move to reservoir tanks that feed the cooker.","inputs":["sugar","butter","palm-oil","condensed-milk"]},{"name":"Cook off the water","process":"cook","text":"Surplus water evaporates in the cooker. One equipment maker's version spreads the syrup as a thin film and works fast, so the milk solids spend little time near scorching heat.","inputs":[]},{"name":"Hold until it browns","process":"cook","text":"The liquid stays hot long enough to caramelize, which sets the flavor and color. Traditional hard toffee reaches the hard crack stage at 149 to 154 degrees Celsius.","inputs":[],"spec":"149 to 154 °C for hard crack"},{"name":"Fold in nuts","process":"mix","text":"Almonds, other nuts or raisins are sometimes stirred through the hot batch. Modern lines can carry such pieces without crushing them.","inputs":["almonds"]},{"name":"Cool to a plastic state","process":"chill","text":"On the traditional line the caramelized liquid cools until it is soft and workable.","inputs":[]},{"name":"Shape a continuous rope","process":"extrude","text":"The plastic mass is molded into one long shaped rope. That rope limits the shapes a factory can make, since every piece is cut from it.","inputs":[]},{"name":"Cut the pieces","process":"cut","text":"A cutter chops the rope into individual toffees. Changes in room temperature can leave them with poorly squared ends.","inputs":[]},{"name":"Or deposit into molds","process":"cast","text":"Newer lines pump cooked toffee straight into silicone or metal molds. Toffee tends to stretch into a tail at the nozzle, and one patent breaks it with a pulse of heated compressed air.","inputs":[]},{"name":"Wrap the pieces","process":"package","text":"Pieces go through a wrapping machine. Regular shapes from a mold handle better here than uneven cut ones.","inputs":[]}],"facts":["Nobody knows where the word toffee comes from, and the earliest printed use dates to 1825.","The very buttery almond version sold in the United States as English toffee is hardly like the toffee sold in the United Kingdom, where it goes by the name butter crunch."],"where":[],"whereNote":null,"sources":[{"title":"US4262709A, Manufacture of toffee and like confectionery","url":"https://patents.google.com/patent/US4262709/en"},{"title":"Caramel and toffee production lines, Baker Perkins","url":"https://www.bakerperkins.com/confectionery/products/toffee-caramel/"},{"title":"Toffee","url":"https://en.wikipedia.org/wiki/Toffee"},{"title":"Caramel","url":"https://en.wikipedia.org/wiki/Caramel"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tofu","name":"Tofu","kind":"product","category":"food","title":"How tofu is made","url":"https://assemblyline.org/make/tofu","stations":7,"upstream":3,"downstream":0,"depth":1,"dek":"Tofu is made like cheese, with soy milk curdled by a mineral and pressed into blocks.","answer":"Soybeans are soaked, ground with water and cooked into soy milk. Filtering removes the pulp, and a coagulant such as calcium sulfate, nigari or glucono delta-lactone is stirred in so the proteins gel into curd. The curds are pressed in molds to drain the whey. The firmness depends on how much liquid is squeezed out.","aka":["bean curd","soybean curd","dubu"],"inputs":["soybeans","water","gypsum"],"uses":[],"grounds":["soybeans","water","gypsum"],"upstreamSlugs":["soybeans","water","gypsum"],"downstreamSlugs":[],"steps":[{"name":"Soak the beans","process":"wash","text":"Dried soybeans swell in water for hours until they are plump. Soft beans grind to a smoother slurry.","inputs":["soybeans","water"]},{"name":"Grind with water","process":"crush","text":"The soaked beans are ground with fresh water into a thick slurry. Grinding breaks the cells open and releases protein and oil.","inputs":[]},{"name":"Boil the slurry","process":"cook","text":"Steam cooks the slurry. Heat deactivates compounds in raw soy that interfere with digestion, and it prepares the proteins to gel.","inputs":[]},{"name":"Strain out the pulp","process":"separate","text":"A filter press or centrifuge separates the liquid soy milk from the fibrous pulp, called okara. The pulp is used in feed or other foods.","inputs":[]},{"name":"Curdle with a coagulant","process":"react","text":"Calcium sulfate, magnesium chloride (nigari), glucono delta-lactone or an edible acid is stirred into hot soy milk. Calcium and magnesium ions link the soy proteins into a gel. The choice of coagulant sets the texture, with gypsum giving tender but slightly brittle tofu and GDL giving silken tofu.","inputs":["gypsum"]},{"name":"Press into blocks","process":"press","text":"The curd is broken up, ladled into cloth-lined molds and pressed so whey runs out. Pressing longer makes firm and extra-firm tofu, while silken tofu is left to set unpressed in its package.","inputs":[]},{"name":"Cut, chill and pack","process":"package","text":"Blocks are cut to size, cooled in clean water, packed in tubs with water and often pasteurized.","inputs":[]}],"facts":["Chinese legend credits tofu to Prince Liu An, who lived from 179 to 122 BC.","Benjamin Franklin mentioned tofu in a 1770 letter, calling it cheese from China.","Before refrigeration, tofu in China was usually sold only in winter."],"where":[],"whereNote":null,"sources":[{"title":"Tofu","url":"https://en.wikipedia.org/wiki/Tofu"},{"title":"Soy sauce","url":"https://en.wikipedia.org/wiki/Soy_sauce"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"toilet","name":"Toilet","kind":"product","category":"minerals","title":"How toilets are made","url":"https://assemblyline.org/make/toilet","stations":7,"upstream":5,"downstream":0,"depth":1,"dek":"Toilets shrink in the kiln, so each plaster mold is deliberately oversized, and it lasts for up to 100 castings.","answer":"Toilets are vitreous china: ball clay, china clay, feldspar and silica in water, poured as slip into oversized plaster molds. After a couple of hours the surplus drains away. The casting is trimmed, dried for 8 to 10 hours, sprayed with glaze and fired for about 40 hours. Leak and flush tests come before the fittings go on.","aka":["water closet","commode","ceramic toilet"],"inputs":["clay","kaolin","feldspar","silica-sand","water"],"uses":[],"grounds":["clay","kaolin","feldspar","silica-sand","water"],"upstreamSlugs":["clay","kaolin","feldspar","silica-sand","water"],"downstreamSlugs":[],"steps":[{"name":"Blend the slip","process":"mix","text":"Ball clay, china clay, feldspar and silica are mixed with water into a thick slurry called slip and stirred until free of lumps and air pockets.","inputs":["clay","kaolin","feldspar","silica-sand","water"]},{"name":"Pour into plaster molds","process":"cast","text":"Slip fills an oversized plaster mold and sits for a couple of hours while the plaster soaks water out of it. The excess is drained. Some plants use high-pressure casting, which is faster and less affected by the weather.","inputs":[]},{"name":"Demold and trim","process":"cut","text":"The soft casting, now called greenware, comes out of the mold. Workers remove seams and smooth the surface by hand, because at this stage a knock can ruin it.","inputs":[]},{"name":"Dry the greenware","process":"dry","text":"A dryer at around 90 to 100 °C takes out most of the moisture over 8 to 10 hours, so the piece will not crack in the kiln. Inspectors then mark any damage and sand the surface.","inputs":[],"spec":"90-100 °C"},{"name":"Spray on glaze","process":"coat","text":"Spray guns lay about 1 mm of glaze over the dry body, in several passes on some lines. Once fired, that layer seals out stains and bacteria.","inputs":[],"spec":"about 1 mm"},{"name":"Fire in the kiln","process":"fire","text":"The kiln climbs to around 1,200 °C, and some makers go over 1,280 °C, across about 40 hours. The clay vitrifies into a waterproof body and shrinks to its final size.","inputs":[],"spec":"about 40 hours"},{"name":"Test and fit","process":"inspect","text":"Each piece is checked for leaks and flushed. Rough spots are polished, and then the seat and flushing mechanism are added.","inputs":[]}],"facts":["Slip casting appears to have been reinvented in England around 1745 and became the main technique for sanitaryware by the end of that century.","Sir John Harington designed a precursor of the flush toilet in 1596, but such systems did not come into widespread use until the late nineteenth century.","William Elvis Sloan invented the Flushometer in 1906, using pressure instead of a tank."],"where":[],"whereNote":null,"sources":[{"title":"Victorian Plumbing: How is a toilet made?","url":"https://victorianplumbing.co.uk/bathroom-ideas-and-inspiration/how-is-a-toilet-made"},{"title":"Jabra Sanitary: How toilets are made","url":"https://jabrasanitary.com/how-toilets-are-made"},{"title":"Toilet","url":"https://en.wikipedia.org/wiki/Toilet"},{"title":"Slip casting","url":"https://en.wikipedia.org/wiki/Slip_casting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"toilet-paper","name":"Toilet paper","kind":"product","category":"wood-paper","title":"How toilet paper is made","url":"https://assemblyline.org/make/toilet-paper","stations":6,"upstream":34,"downstream":0,"depth":9,"dek":"Toilet paper is made of short fibers so that a roll falls apart in a septic tank.","answer":"Toilet paper is tissue, the lightest paper made. A machine lays a thin wet web of short fibers on a felt, presses it onto one huge steam-heated drum, then scrapes it off with a blade, which crinkles it. The crinkled sheet is embossed, layered into plies, perforated and wound onto cardboard cores.","aka":["toilet tissue","bathroom tissue","loo roll","toilet roll"],"inputs":["wood-pulp","water","adhesive","cardboard"],"uses":[],"grounds":["water","timber","rock-salt","limestone","air","crude-oil","natural-gas","sulfur","coal"],"upstreamSlugs":["wood-pulp","water","adhesive","cardboard","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","rock-salt","limestone","air","hydrogen","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","nitric-acid","crude-oil","natural-gas","naphtha","sulfur","benzene","toluene","coal"],"downstreamSlugs":[],"steps":[{"name":"Mix short, soft fibers","process":"mix","text":"Pulp from pulpwood trees, recycled fiber, sugar cane waste or bamboo is blended into a thin slurry. Fibers are chosen short on purpose. Short fibers fall apart in a drain, and long ones hold the sheet together.","inputs":["wood-pulp","water"]},{"name":"Form a delicate web","process":"cast","text":"The slurry spreads between a wire and a fabric felt as they wrap around a roll. Almost all of the water drains through, leaving a thin, fragile web.","inputs":[]},{"name":"Glue it to a hot drum","process":"dry","text":"The web is pressed from the felt onto the Yankee, a single enormous steam-heated drying cylinder under a hot air hood. The cylinder is sprayed with an adhesive so the web sticks and dries in a moment.","inputs":["adhesive"]},{"name":"Scrape it off crinkled","process":"knead","text":"A doctor blade scrapes the dry sheet off the drum. The sheet bunches up as it comes off, and those tiny crinkles are what make tissue soft and stretchy. The glue strength, blade angle and speed set how crinkled it gets.","inputs":[]},{"name":"Emboss and ply up","process":"laminate","text":"Rolls of tissue are unwound together, patterned with embossing rolls and pressed so two or more plies hold to each other.","inputs":[]},{"name":"Wind, perforate and slice","process":"cut","text":"The layered tissue is rolled onto cardboard tubes, and blades cut perforation lines at the right spacing. A long log of rolls is then sawn into individual rolls and wrapped.","inputs":["cardboard"]}],"facts":["Chinese records show toilet paper made in volume by the early 14th century, with ten million packages a year in what is now Zhejiang.","Joseph Gayetty is widely credited with the first commercially available toilet paper in the United States, which he introduced in 1857 as flat sheets watermarked with his name.","The average American uses about 23.6 rolls of toilet paper a year."],"where":[],"whereNote":null,"sources":[{"title":"Toilet paper","url":"https://en.wikipedia.org/wiki/Toilet_paper"},{"title":"Tissue paper","url":"https://en.wikipedia.org/wiki/Tissue_paper"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"toluene","name":"Toluene","kind":"material","category":"chemicals","title":"How toluene is made","url":"https://assemblyline.org/make/toluene","stations":5,"upstream":6,"downstream":284,"depth":3,"dek":"It is named after Tolu, a Colombian tree balsam. Today most of it comes from refineries chasing octane.","answer":"Refineries make this sweet-smelling liquid as a by-product of chasing octane. Catalytic reformers rearrange naphtha into ring-shaped aromatics, and solvent extraction and distillation then split out benzene, toluene and xylenes. Coal tar gives a smaller stream. Much of the output ends up as benzene and xylenes, as paint and adhesive solvent, or back in gasoline.","aka":["methylbenzene","toluol"],"inputs":["naphtha","coal"],"uses":["benzene"],"grounds":["coal","crude-oil","water","natural-gas"],"upstreamSlugs":["naphtha","coal","crude-oil","water","hydrogen","natural-gas"],"downstreamSlugs":["benzene","polystyrene","abs-plastic","nylon","synthetic-rubber","phenol","spandex","styrene","acetone","surfboard","bike-helmet","ballpoint-pen","polystyrene-foam","foam-cup","smoke-detector","compact-disc","inkjet-printer","lipstick","hearing-aid","thermometer","lego-brick","3d-printer-filament","laptop","television","computer-keyboard","computer-mouse","headphones","rubiks-cube","snowboard","action-figure","harmonica","globe","suitcase","high-heels","wireless-earbuds","phone-charger","usb-cable","game-console","wifi-router","e-reader","graphics-card","remote-control","electric-toothbrush","toothbrush","mascara","drone","tire","airbag","guitar","violin","basketball","velcro","dishwasher","office-chair","roller-skates","tennis-racket","volleyball","kite","fashion-doll","ukulele","drumstick","eyeshadow","dental-floss","aluminum-window-frame","underwear","leggings","swimsuit","down-jacket","raincoat","handbag","backpack","hiking-boots","flag","socks","carpet","zipper","rope","syringe","rubber","nitrile-glove","chewing-gum","golf-ball","pencil-eraser","flip-flops","rubber-boots","aspirin","acetaminophen","polycarbonate","epoxy","billiard-ball","brake-pad","phenolic-resin","shoelace","eyeglass-frame","cellulose-acetate","car","electric-car","bicycle","motorcycle","jeans","vacuum-cleaner","electric-kettle","pencil","shipping-container","tennis-ball","baseball","soccer-ball","ski","golf-club","football","cricket-bat","dumbbell","treadmill","wheelchair","ladder","wheelbarrow","fire-extinguisher","loudspeaker","sneaker","leather-shoe","umbrella","led-bulb","eyeglass-lens","sunglasses","blender","smartwatch","digital-camera","camera-lens","adhesive","printed-circuit-board","wind-turbine","electric-motor","rebar","aluminum-can","airplane","fishing-rod","prosthetic-leg","ink","photoresist","dice","adhesive-bandage","credit-card","duct-tape","ev-battery","nail","insulation","popcorn","windshield","skateboard","piano","drum-kit","paper-straw","paper-bag","pizza-box","laminate-floor","wooden-chair","door","clear-tape","staple","sofa","ice-skates","dartboard","chess-set","board-game","jigsaw-puzzle","cello","snow-globe","pinball-machine","kitchen-sponge","sanitary-pad","cotton-swab","roof-shingle","double-glazed-window","sailboat","dress-shirt","suit","wallet","microphone","plywood","mdf","cardboard","cardboard-box","toilet-paper","book","envelope","sticky-notes","playing-cards","match","baseball-cap","mattress","diaper","pacemaker","smartphone","hard-drive","solid-state-drive","microwave-oven","washing-machine","satellite","rocket","locomotive","elevator","ceiling-fan","refrigerator","air-conditioner","subway-train","concrete","skyscraper","deodorant","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","plastic-bag","tin-can","paper-cup","wallpaper","marker-pen","highlighter","frisbee","trading-cards","candy-coated-chocolate","floor-tile","vinyl-floor","vinyl-record","newspaper","banknote","t-shirt","microchip","memory-chip","lcd-screen","indium-tin-oxide","fireworks","plastic-wrap","cake-mix","hair-dye","tampon","soap","toothpaste","detergent","paperclip","donut","corn-flakes","cotton-candy","crayon","candle","salsa","canned-meat","fish-sticks","zip-bag","pillow","mouthwash","cough-syrup","light-switch","facial-tissue","paint","condensed-milk","baby-formula","coconut-milk","canned-soup","oled-screen","aa-battery","candy-cane","scissors","mirror","container-ship","water-bottle","water-heater","bowling-ball","toy-car","coil-spring","hammer","gas-cylinder","neon-sign","suspension-bridge-cable","leather-belt","toffee","padlock"],"steps":[{"name":"Reform the naphtha","process":"react","text":"Heated naphtha passes over a platinum catalyst. Straight-chain hydrocarbons are rearranged and partly stripped of hydrogen, leaving a high-octane liquid called reformate that is rich in aromatics.","inputs":["naphtha"]},{"name":"Or strip coal tar","process":"refine","text":"Coke ovens give a second, smaller source. Light oil from coal tar is 15 to 20 percent of this hydrocarbon, and it is collected for commercial use alongside the refinery supply.","inputs":["coal"]},{"name":"Pull out the aromatics","process":"separate","text":"A solvent extraction step lifts the ring compounds out of the reformate, leaving the rest to go on to the gasoline pool. The extract is known as BTX, for benzene, toluene and xylenes.","inputs":[]},{"name":"Distill the three apart","process":"refine","text":"Distillation columns split the BTX stream by boiling point. This one boils at 110.6 °C, between its two siblings, and comes off the column as a colorless liquid.","inputs":[]},{"name":"Send it three ways","process":"fill","text":"Part goes on to be converted into benzene and xylenes, part into solvents for thinners, paints, lacquers and adhesives, and part into gasoline as an octane booster. It is flammable and toxic, so it moves in sealed tankers.","inputs":[]}],"facts":["Formula One engines have used toluene as an octane booster.","Toluene has largely replaced benzene as an aromatic solvent because it is much less toxic.","It was first named after being isolated in 1841 from balsam of Tolu, a tropical tree extract."],"where":[],"whereNote":null,"sources":[{"title":"Toluene","url":"https://en.wikipedia.org/wiki/Toluene"},{"title":"Toluene (Britannica)","url":"https://www.britannica.com/science/toluene"},{"title":"Catalytic reforming","url":"https://en.wikipedia.org/wiki/Catalytic_reforming"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tomatoes","name":"Tomatoes","kind":"raw","category":"farm","title":"How tomatoes are grown and harvested","url":"https://assemblyline.org/make/tomatoes","stations":5,"upstream":0,"downstream":4,"depth":0,"dek":"Fresh tomatoes get picked by hand four to six times a season, while a canning harvester cuts the whole vine.","answer":"Commercial tomatoes start in a greenhouse, then go out as seedlings into raised beds under plastic mulch with drip irrigation. Growers weave twine between stakes to hold fresh-market plants up, and crews pick them by hand several times, often at the mature green stage. Canning crops meet a machine that cuts the whole vine and sorts the fruit with sensors.","aka":["tomato farming","tomato harvest","greenhouse tomatoes","processing tomatoes"],"inputs":[],"uses":["ketchup","salsa","frozen-pizza","canned-soup"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["ketchup","salsa","frozen-pizza","canned-soup"],"steps":[{"name":"Start seedlings under glass","process":"grow","text":"Seed goes into cell trays in a greenhouse, and the plants stay there for 42 to 56 days. Container-grown seedlings carry their growing medium out with their roots, so they take the move outdoors with less shock.","inputs":[],"spec":"42 to 56 days in the greenhouse"},{"name":"Plant into mulched beds","process":"grow","text":"Once soil 3 inches down reaches 60 °F, a transplanter sets the seedlings into raised beds covered in red or black plastic. Drip lines deliver water and fertilizer for the rest of the season.","inputs":[]},{"name":"Weave twine between stakes","process":"grow","text":"Fresh-market plants need holding up off the ground. Stakes of wood, 4 to 4.5 feet tall, go in between every second plant, and twine runs along both sides of the row, normally at three heights.","inputs":[]},{"name":"Hand-pick the fresh crop","process":"harvest","text":"Crews work through a field four to six times a season. Wholesale fruit comes off at the mature green to breaker stage so it can survive shipping, and some of it is ripened later with ethylene gas. Buckets get tipped into bins holding 800 to 1,200 pounds, which ride to a packinghouse.","inputs":[]},{"name":"Machine-cut the canning crop","process":"harvest","text":"For canning, a machine cuts the entire vine and uses sensors to split ripe fruit from the rest of the plant. What is left returns to the farm as green manure or gets grazed by livestock.","inputs":[]}],"facts":["Modern varieties were bred to ripen uniformly red, and that trait cut sugar in the ripe fruit by 10 to 15%.","A tomato called Flavr Savr became the first genetically modified food on sale.","A fall of just over 6 inches onto something hard can bruise a tomato inside, with nothing to see on the skin."],"where":[{"place":"China","share":"36% of world output"},{"place":"India","share":"secondary producer"},{"place":"Turkey","share":"secondary producer"},{"place":"United States","share":"secondary producer"}],"whereNote":"2023, share of the 192 million tonnes of tomatoes produced worldwide.","sources":[{"title":"Tomato","url":"https://en.wikipedia.org/wiki/Tomato"},{"title":"Tomato Production, Penn State Extension","url":"https://extension.psu.edu/tomato-production"},{"title":"Commercial Tomato Production Handbook, University of Georgia Extension","url":"https://extension.uga.edu/publications/detail.html?number=B1312&title=commercial-tomato-production-handbook"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tonic-water","name":"Tonic water","kind":"product","category":"drink","title":"How tonic water is made","url":"https://assemblyline.org/make/tonic-water","stations":5,"upstream":58,"downstream":0,"depth":9,"dek":"Tonic water began as malaria medicine, and US law now caps its quinine at 83 milligrams per liter.","answer":"Tonic water is carbonated water with a little quinine dissolved in it, taken from the bark of the cinchona tree, plus sweetener and often citrus flavor. The quinine gives it a bitter bite. Modern tonic holds a tiny fraction of the quinine of the medicinal original, with the US limit set at 83 parts per million.","aka":["quinine water","Indian tonic"],"inputs":["sugar","corn-syrup","water","carbon-dioxide","glass-bottle","aluminum-can"],"uses":[],"grounds":["water","sugarcane","sugar-beet","corn","natural-gas","limestone","silica-sand","rock-salt","trona","crude-oil","coal","air","bauxite","soybeans","rapeseed","clay","titanium-ore","iron-ore","sulfur"],"upstreamSlugs":["sugar","corn-syrup","water","carbon-dioxide","glass-bottle","aluminum-can","sugarcane","sugar-beet","lime","corn","corn-starch","natural-gas","yeast","limestone","silica-sand","soda-ash","polyethylene","aluminum","ink","epoxy","molasses","rock-salt","ammonia","trona","ethylene","crude-oil","coal","petroleum-coke","alumina","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","phenol","propylene","acetone","chlorine","caustic-soda","air","naphtha","bauxite","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","coke","oxygen","sulfuric-acid","iron-ore","sulfur","benzene","hydrogen","methanol","toluene"],"downstreamSlugs":[],"steps":[{"name":"Strip the cinchona bark","process":"harvest","text":"Quinine comes from the bark of cinchona trees, which remain the only economically practical source. The tree is native to Peru and neighboring countries.","inputs":[]},{"name":"Pull out the quinine","process":"refine","text":"Quinine was first isolated from cinchona bark in 1820. It is drawn out of the bark and purified into the bitter compound used in drinks.","inputs":[]},{"name":"Mix the bitter syrup","process":"mix","text":"A tiny amount of quinine goes into a syrup with sugar or high-fructose corn syrup and citrus flavor. Diet versions swap in sugar substitutes.","inputs":["sugar","corn-syrup","water"]},{"name":"Carbonate the blend","process":"react","text":"Carbon dioxide is dissolved into the water under pressure, and the syrup is blended in.","inputs":["carbon-dioxide"]},{"name":"Bottle and seal","process":"fill","text":"The sparkling tonic is sealed into bottles or cans so the gas stays in.","inputs":["glass-bottle","aluminum-can"]}],"facts":["The first commercial tonic water was patented in 1858 by Erasmus Bond of Pitt and Co. and made at a factory in London.","British officials in India mixed their anti-malaria quinine with soda and sugar, and the gin and tonic grew out of it.","Europe's limit of 100 milligrams of quinine per liter is only 0.25 to 0.50 percent of the strength of the original medicinal tonic."],"where":[],"whereNote":null,"sources":[{"title":"Tonic water","url":"https://en.wikipedia.org/wiki/Tonic_water"},{"title":"Quinine","url":"https://en.wikipedia.org/wiki/Quinine"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"toothbrush","name":"Toothbrush","kind":"product","category":"body-health","title":"How toothbrushes are made","url":"https://assemblyline.org/make/toothbrush","stations":7,"upstream":56,"downstream":0,"depth":9,"dek":"A modern toothbrush handle is shot out of a mold in seconds, then tufts of nylon are stapled into it.","answer":"A toothbrush handle is molded from plastic pellets that are melted and injected into a steel mold. Separate machine stations then punch tiny holes, press in tufts of nylon filament held by a thin metal staple, trim the bristles to a pattern, round their tips and package the brush.","aka":["tooth brush","manual toothbrush"],"inputs":["polypropylene","pigment","synthetic-rubber","nylon","steel","cardboard"],"uses":[],"grounds":["iron-ore","sulfur","water","crude-oil","titanium-ore","air","natural-gas","limestone","dolomite","manganese-ore","timber","rock-salt","coal","quartz"],"upstreamSlugs":["polypropylene","pigment","synthetic-rubber","nylon","steel","cardboard","propylene","iron-ore","titanium-dioxide","carbon-black","sulfur","naphtha","benzene","ethylene","styrene","water","nitric-acid","ammonia","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","wood-pulp","adhesive","crude-oil","titanium-ore","chlorine","coke","sulfuric-acid","air","hydrogen","toluene","natural-gas","limestone","dolomite","silicon","propane","manganese-ore","timber","caustic-soda","hydrogen-peroxide","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","rock-salt","coal","quartz","charcoal","methanol","phenol","acetone"],"downstreamSlugs":[],"steps":[{"name":"Melt plastic pellets","process":"melt","text":"Pellets of polypropylene are heated in a screw barrel until they turn into a thick melt. Color pigment is blended in at this stage.","inputs":["polypropylene","pigment"]},{"name":"Inject the handle","process":"mold","text":"The melt is forced into a cooled steel mold shaped like the handle. A soft rubbery grip can be molded onto the handle in a second shot.","inputs":["synthetic-rubber"]},{"name":"Spin the nylon","process":"draw","text":"Molten nylon is pushed through tiny holes and stretched into long filaments. Stretching lines up the molecules, so the filament springs back when bent.","inputs":["nylon"]},{"name":"Cut the bristle tufts","process":"cut","text":"The filaments are cut into short lengths and gathered into tufts. Each tuft is doubled over and held ready to be pushed into a hole.","inputs":[]},{"name":"Punch in the tufts","process":"assemble","text":"A machine drives each folded tuft into a hole with a tiny metal anchor that pins it in place. Dozens of tufts go in within seconds.","inputs":["steel"]},{"name":"Trim and round the tips","process":"grind","text":"Blades shave the bristles to the chosen pattern, then tips are ground and polished so they do not scratch gums. Rounded ends are what dentists look for.","inputs":[]},{"name":"Pack the brushes","process":"package","text":"Each brush is sealed in a plastic blister or paper box and counted into shipping cartons.","inputs":["cardboard"]}],"facts":["The first nylon-bristle toothbrush went on sale on February 24, 1938.","Brushes with horse or boar bristles were still imported to Britain from China until the middle of the 20th century.","The first electric toothbrush, the Broxodent, was invented in Switzerland in 1954."],"where":[],"whereNote":null,"sources":[{"title":"Toothbrush","url":"https://en.wikipedia.org/wiki/Toothbrush"},{"title":"Injection moulding","url":"https://en.wikipedia.org/wiki/Injection_moulding"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"toothpaste","name":"Toothpaste","kind":"product","category":"body-health","title":"How toothpaste is made","url":"https://assemblyline.org/make/toothpaste","stations":7,"upstream":64,"downstream":0,"depth":10,"dek":"The gritty part of toothpaste can be ground limestone or silica, milled fine enough to polish and not scratch.","answer":"Toothpaste is a paste of fine abrasive powder, a humectant such as glycerol that keeps it from drying out, water, a foaming detergent, flavor and fluoride. A vacuum mixer blends the batch smooth, and the paste is pumped into laminated tubes that are then crimped shut at the bottom.","aka":["dentifrice","tooth paste"],"inputs":["limestone","silica-sand","water","glycerin","titanium-dioxide","polyethylene","aluminum-foil","cardboard-box"],"uses":[],"grounds":["limestone","silica-sand","water","titanium-ore","oil-palm-fruit","soybeans","rapeseed","clay","rock-salt","natural-gas","coal","air","sulfur","crude-oil","bauxite","timber","iron-ore","corn","sugarcane","sugar-beet"],"upstreamSlugs":["limestone","silica-sand","water","glycerin","titanium-dioxide","polyethylene","aluminum-foil","cardboard-box","palm-oil","vegetable-oil","caustic-soda","methanol","titanium-ore","chlorine","coke","oxygen","sulfuric-acid","ethylene","aluminum","cardboard","ink","adhesive","oil-palm-fruit","soybeans","rapeseed","hexane","clay","rock-salt","natural-gas","coal","air","sulfur","naphtha","crude-oil","petroleum-coke","alumina","wood-pulp","phenolic-resin","carbon-black","pigment","ethanol","acrylic","epoxy","polyurethane","paraffin-wax","hydrogen","bauxite","lime","timber","hydrogen-peroxide","phenol","formaldehyde","iron-ore","corn","sugarcane","yeast","propylene","ammonia","acetone","nitric-acid","benzene","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Grind the abrasive","process":"crush","text":"Calcium carbonate from limestone or precipitated silica is milled into a powder so fine it feels smooth. This grit is what lifts plaque and food off teeth.","inputs":["limestone","silica-sand"]},{"name":"Prepare the gel base","process":"mix","text":"Water, glycerol or sorbitol, and a thickener are mixed into a clear gel. The sugar alcohols stop the paste from drying into powder at the nozzle.","inputs":["water","glycerin"]},{"name":"Fold in the powders","process":"mix","text":"The abrasive, white pigment, fluoride and sweetener are added to the gel in a vacuum mixer. Pulling out the air keeps bubbles from forming, so the paste comes out dense and glossy.","inputs":["titanium-dioxide"]},{"name":"Add foam and flavor","process":"mix","text":"Last in is the detergent that makes the foam, followed by mint or another flavoring. Flavor goes in late because it evaporates easily.","inputs":[]},{"name":"Test each batch","process":"inspect","text":"Samples are tested for thickness, acidity, fluoride level and microbes before the batch is released to the filling line.","inputs":[]},{"name":"Fill the tubes","process":"fill","text":"Empty tubes made of plastic layers, often with a thin metal foil inside, ride on a carousel under a nozzle. Each gets a measured dose and then has its open end flattened and heat-sealed.","inputs":["polyethylene","aluminum-foil"]},{"name":"Box the tubes","process":"package","text":"Sealed tubes are coded with a batch number, slid into printed cartons and packed in cases.","inputs":["cardboard-box"]}],"facts":["Egyptian tooth powder of about 5000 BC contained ashes of ox hooves, pumice, burnt eggshells and myrrh.","Japan's Edo-period book of 1769 advertised a toothpaste sold in a box."],"where":[],"whereNote":null,"sources":[{"title":"Toothpaste","url":"https://en.wikipedia.org/wiki/Toothpaste"},{"title":"Toothbrush","url":"https://en.wikipedia.org/wiki/Toothbrush"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"toothpick","name":"Toothpick","kind":"product","category":"wood-paper","title":"How toothpicks are made","url":"https://assemblyline.org/make/toothpick","stations":6,"upstream":1,"downstream":0,"depth":1,"dek":"A toothpick begins as one thin sheet of birch, peeled off a spinning log the way a paper towel comes off its roll.","answer":"Birch logs are stripped of bark and then peeled, like unrolling a roll of paper, into one long thin sheet of wood. A puncher stamps toothpick shapes out of the sheet at great speed. The soft picks are baked hard in a dryer, tumbled with talcum powder to polish them, sifted for damaged ones, and counted into boxes.","aka":["wooden toothpick","tooth pick"],"inputs":["timber"],"uses":[],"grounds":["timber"],"upstreamSlugs":["timber"],"downstreamSlugs":[],"steps":[{"name":"Strip off the bark","process":"machine","text":"Grippers lift birch logs into a debarker, which makes two passes with a blade and leaves a smooth cylinder of bare wood.","inputs":["timber"]},{"name":"Peel a paper-thin sheet","process":"cut","text":"The log is spun against a row of blades that unravel it into a continuous sheet about a millimeter thick, in the same way a paper towel unrolls.","inputs":[]},{"name":"Punch the picks","process":"stamp","text":"The sheet is gathered into a billet, which is carried to a puncher. It cuts identical toothpick strips at great speed, and the result is a pile of small soft picks.","inputs":[]},{"name":"Bake them hard","process":"dry","text":"The soft picks go into a dryer for hours until the wood sets firm.","inputs":[],"spec":"12 hours"},{"name":"Tumble with talc","process":"grind","text":"Friction and talcum powder polish the picks and round off rough points. The tumbling takes several hours.","inputs":[],"spec":"four hours"},{"name":"Sift, count and pack","process":"package","text":"A sifter shakes out broken picks. A blower and conveyor count the good ones into boxes.","inputs":[]}],"facts":["The toothpick is the oldest tool for cleaning teeth, and lesions on 1.8-million-year-old remains from Dmanisi, Georgia, are thought to come from one.","The first toothpick-making machine was built in 1869 by Marc Signorello."],"where":[],"whereNote":null,"sources":[{"title":"Toothpick","url":"https://en.wikipedia.org/wiki/Toothpick"},{"title":"How Do They Make Toothpicks?","url":"https://itstillworks.com/13652669/how-do-they-make-toothpicks"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tortilla","name":"Tortilla","kind":"product","category":"food","title":"How tortillas are made","url":"https://assemblyline.org/make/tortilla","stations":7,"upstream":30,"downstream":0,"depth":9,"dek":"Corn tortillas start with corn cooked in limewater, a trick the Aztecs' ancestors worked out long ago.","answer":"For corn tortillas, whole kernels are cooked in limewater, a treatment called nixtamalization, then ground into masa dough. Factories press or sheet the masa into rounds and pass them through a long oven. Flour tortillas skip the limewater and are pressed from wheat dough with shortening. Both are cooled and bagged.","aka":["corn tortilla","flour tortilla","masa","taco shell"],"inputs":["corn","lime","water","flour","vegetable-oil"],"uses":[],"grounds":["corn","water","limestone","wheat","soybeans","rapeseed","clay","air","crude-oil","natural-gas","sugarcane","sugar-beet"],"upstreamSlugs":["corn","lime","water","flour","vegetable-oil","limestone","wheat","vitamin-c","soybeans","rapeseed","hexane","clay","corn-starch","hydrogen","air","sugar","plastic-bottle","crude-oil","natural-gas","sugarcane","sugar-beet","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","yeast","molasses"],"downstreamSlugs":[],"steps":[{"name":"Cook the corn in limewater","process":"cook","text":"Whole kernels are heated in an alkaline solution of calcium hydroxide, then steeped overnight. The treatment loosens the hulls, softens the kernels and has the largest impact on the final product.","inputs":["corn","lime","water"]},{"name":"Wash off the hulls","process":"wash","text":"The cooking liquid is drained away and the swollen kernels, now called nixtamal, are rinsed. Hulls and excess lime wash away with the water.","inputs":[]},{"name":"Grind to masa","process":"grind","text":"Stone or rotating mills crush the nixtamal into a sticky dough called masa. Some factories dry and grind the nixtamal into masa harina flour, which can be rehydrated at any plant.","inputs":[]},{"name":"Sheet and cut the rounds","process":"roll","text":"Masa is pushed between rollers into a thin sheet, and a rotating cutter stamps out circles. Scrap dough is returned to the start of the line.","inputs":[]},{"name":"Bake on stacked belts","process":"bake","text":"Rounds ride through a gas-fired oven on stacked conveyor belts and drop from one belt to the next, which flips them so both sides cook. The rounds puff slightly and pick up their brown spots.","inputs":[]},{"name":"Cool before sealing","process":"chill","text":"Tortillas cool on a long conveyor so steam does not condense inside the bag and encourage mold. They are stacked, counted and bagged.","inputs":[]},{"name":"Press the flour version","process":"press","text":"Flour tortillas are made from wheat flour, water and shortening. Most are hot pressed, which makes an irregular, strong disk. The rest are die-cut for a perfectly round, drier product.","inputs":["flour","vegetable-oil"]}],"facts":["Nixtamalization was first done with wood ash before lime took over.","Remnants of a comal and processed lime from around 700 BC have been found at Chalcatzingo.","Tortillas lack the amino acids lysine and tryptophan, so they are often fortified."],"where":[],"whereNote":null,"sources":[{"title":"Tortilla","url":"https://en.wikipedia.org/wiki/Tortilla"},{"title":"Nixtamalization","url":"https://en.wikipedia.org/wiki/Nixtamalization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"trading-cards","name":"Trading cards","kind":"product","category":"play","title":"How trading cards are made","url":"https://assemblyline.org/make/trading-cards","stations":6,"upstream":56,"downstream":0,"depth":10,"dek":"A booster pack is dealt by machine: cards are slit from 121-card sheets, then dropped in from separate rarity groups.","answer":"Trading cards are offset-printed in grids on large sheets of cardstock, as many as 121 to a sheet. Rare cards get foil or texture. A slitter cuts each sheet into strips and then cards, and machines collate them from separate groups so every pack gets a set mix of rarities. Packs are wrapped, weighed and boxed.","aka":["collectible cards","baseball cards","sports cards","trading card game cards"],"inputs":["cardboard","ink","plastic","cardboard-box"],"uses":[],"grounds":["water","natural-gas","timber","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","limestone","coal","sugar-beet"],"upstreamSlugs":["cardboard","ink","plastic","cardboard-box","wood-pulp","water","adhesive","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","naphtha","natural-gas","ethylene","propylene","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","hydrogen","rock-salt","limestone","ammonia","methanol","acetone","nitric-acid","benzene","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Print the sheets","process":"print","text":"Offset presses transfer ink from metal plates to rubber blankets and then to cardstock of 250 to 400 grams per square meter. One sheet can hold 121 cards. Blue or black layers inside the better stocks stop light showing through.","inputs":["cardboard","ink"],"spec":"121 cards to a sheet"},{"name":"Foil the rare cards","process":"coat","text":"Only rare cards get extra finishing. Hot foil stamping presses holographic foil on with a heated die, and raised textures come from UV varnish pushed through a screen.","inputs":[]},{"name":"Slit the sheets apart","process":"cut","text":"A slitting machine cuts each sheet into strips and then into individual cards. Every card sits in a planned position on the sheet, so it comes out in the same place in every deck. Off-center cuts hurt a card's value.","inputs":[]},{"name":"Check borders and corners","process":"inspect","text":"Corners are smoothed, and staff pull cards to check thickness and the width of their borders.","inputs":[]},{"name":"Collate the rarity groups","process":"mix","text":"Machines build each pack from separate streams. One Star Trek line dropped five cards from one group, added a rotating special card, then laid four cards from another group on top. Premium inserts are scattered by random numbers so they do not cluster in a box.","inputs":[]},{"name":"Wrap and pack","process":"package","text":"Packs are wrapped automatically in foil or plastic, weighed, and packed by hand into display boxes.","inputs":["plastic","cardboard-box"]}],"facts":["One North Carolina plant's presses are 120 feet long and print 26.62 million Pokemon cards a day.","Printers keep new cards secret, because customers do not want them leaked before release.","Topps started putting trading cards in bubble gum packs in 1950."],"where":[],"whereNote":null,"sources":[{"title":"Triangle Company Plays a Big Hand in Trading Card Business","url":"https://www.wral.com/story/148959"},{"title":"Leaked internal video reveals how Pokemon cards are made","url":"https://nextshark.com/video-how-pokemon-cards-are-made"},{"title":"How Are Trading Cards Made: From Sheet to Pack","url":"https://climbtheladder.com/how-are-trading-cards-made-from-sheet-to-pack/"},{"title":"Trading card","url":"https://en.wikipedia.org/wiki/Trading_card"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"treadmill","name":"Treadmill","kind":"product","category":"play","title":"How treadmills are made","url":"https://assemblyline.org/make/treadmill","stations":8,"upstream":82,"downstream":0,"depth":9,"dek":"Long before gyms, treadmills ground grain in prisons, and the first home model was inspired by a book on running.","answer":"Treadmill makers combine metalwork, injection molding, electronics assembly and final debugging. Steel is welded or bent into a frame, a wood-fiber deck with a slick surface is pressed, and a belt is stretched over it between two shafts. A motor drives the front shaft, and the machine is measured for load, speed control and emergency stop response before it ships.","aka":["running machine","exercise treadmill"],"inputs":["steel-pipe","mdf","rubber","electric-motor","printed-circuit-board"],"uses":[],"grounds":["timber","natural-latex","sulfur","zinc-ore","air","crude-oil","water","copper-ore","silica-sand","limestone","iron-ore","dolomite","manganese-ore","natural-gas","rock-salt","trona","tin-ore","lead-ore","silver-ore","coal","quartz","corn","sugarcane","sugar-beet"],"upstreamSlugs":["steel-pipe","mdf","rubber","electric-motor","printed-circuit-board","sheet-steel","steel","zinc","timber","paraffin-wax","adhesive","natural-latex","synthetic-rubber","carbon-black","sulfur","copper-wire","epoxy","ball-bearing","copper","fiberglass","photoresist","solder","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","crude-oil","hydrogen","polyethylene","acrylic","polyurethane","water","naphtha","benzene","ethylene","styrene","phenol","propylene","acetone","chlorine","caustic-soda","steel-wire","copper-ore","silica-sand","limestone","soda-ash","phenolic-resin","tin","lead","silver","iron-ore","coke","dolomite","silicon","propane","manganese-ore","natural-gas","ammonia","methanol","nitric-acid","toluene","rock-salt","carbon-dioxide","trona","formaldehyde","tin-ore","lead-ore","silver-ore","coal","quartz","charcoal","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Sample the incoming parts","process":"inspect","text":"Motors, running decks and bonded surface layers are sampled when they arrive, with records and labels that trace each batch. A treadmill maker's factory guide treats this as the first gate against bad parts.","inputs":[]},{"name":"Weld the frame","process":"weld","text":"Steel sections are welded or bent into a rigid frame. Inspectors look for even seams, no false welds and bend angles that match the drawing. At Dyaco's complex in central Taiwan, robots process components with little human help.","inputs":["steel-pipe"]},{"name":"Press the running deck","process":"press","text":"The deck under the belt is built from hardboard. Wood is ground into fine particles, mixed with wax and resin, and pressed into a flat sheet. Plywood may sit beneath for strength.","inputs":["mdf"]},{"name":"Finish the deck surface","process":"coat","text":"The deck is machined for flatness and surface pattern. Wax in the hardboard, or a polymer coating on top, lets the belt slide. Any bonded layer gets random checks for thickness and adhesion.","inputs":[]},{"name":"Stretch the belt between shafts","process":"assemble","text":"A shaft sits before the deck and another behind it. The belt is a loop stretched between the shafts, with the deck holding up the top surface where the runner lands.","inputs":["rubber"]},{"name":"Mount the drive motor","process":"assemble","text":"An electric motor connects to the front shaft, so the top of the belt travels backward. Inspectors check that its wiring is orderly and its mounts are firm. Treadmills with an incline add a lifting element that raises the whole frame.","inputs":["electric-motor"]},{"name":"Wire the control system","process":"assemble","text":"The control electronics and console go in. Circuits should be laid out neatly and connectors seated reliably.","inputs":["printed-circuit-board"]},{"name":"Run the final tests","process":"inspect","text":"The assembled machine gets a first functional test. Testers measure motor performance, deck fatigue, insulation and noise, and maximum load, speed accuracy and emergency stop response should be recorded before shipping. Safety standards for treadmills are written into IEC EN 957.","inputs":[]}],"facts":["English engineer William Cubitt introduced the first treadmills for punishment in 1818, putting idle prisoners to work grinding grain.","The forerunner of the exercise treadmill was built to diagnose heart and lung disease, at the University of Washington in 1952.","William Staub built the first home treadmill after reading a 1968 book that said running eight minutes four to five times a week improves fitness."],"where":[],"whereNote":null,"sources":[{"title":"Treadmill","url":"https://en.wikipedia.org/wiki/Treadmill"},{"title":"Method of forming a deck assembly for an exercise treadmill","url":"https://patents.google.com/patent/US5516471"},{"title":"Factory Inspection Guide: What Should be Focused on When Visiting a Treadmill Factory? (DAPOW)","url":"https://www.dapowsports.com/news/factory-inspection-guide-what-should-be-focused-on-when-visiting-a-treadmill-factory"},{"title":"How Ellipticals Are Made - Taiwan's Mega Factories","url":"https://www.taiwanplus.com/shows/documentary/business-and-tech/589/taiwans-mega-factories/240805004/how-ellipticals-are-made-taiwans-mega-factories"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"trichlorosilane","name":"Trichlorosilane","kind":"material","category":"electronics","title":"How trichlorosilane is made","url":"https://assemblyline.org/make/trichlorosilane","stations":5,"upstream":15,"downstream":35,"depth":4,"dek":"Chip-grade silicon starts as a volatile liquid made by blowing hydrogen chloride over powdered silicon.","answer":"Trichlorosilane is made by passing hydrogen chloride gas over powdered metallurgical silicon at about 300 °C. Yields of 80 to 90 percent are possible. Distillation separates it from other chlorinated silicon by-products, and the purified liquid becomes the starting point for the ultrapure silicon used in chips.","aka":["TCS","silicochloroform"],"inputs":["silicon","hydrochloric-acid"],"uses":["polysilicon"],"grounds":["quartz","coal","timber","water","rock-salt","natural-gas","sulfur","air"],"upstreamSlugs":["silicon","hydrochloric-acid","quartz","coke","coal","charcoal","timber","chlorine","hydrogen","water","rock-salt","sulfuric-acid","natural-gas","sulfur","air"],"downstreamSlugs":["polysilicon","silicon-wafer","microchip","memory-chip","camera-sensor","solar-cell","inkjet-printer","hearing-aid","pacemaker","thermometer","credit-card","smartphone","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","drone","satellite","electric-car","airbag","rocket","smartwatch","wireless-earbuds","phone-charger","usb-cable","digital-camera","game-console","wifi-router","e-reader","graphics-card","remote-control","electric-toothbrush","solar-panel","car"],"steps":[{"name":"Grind the silicon","process":"crush","text":"Metallurgical grade silicon is milled to a powder. A fine powder reacts faster and more evenly.","inputs":["silicon"]},{"name":"Blow in hydrogen chloride","process":"react","text":"In a heated reactor, hydrogen chloride gas is blown through the powder, turning silicon into trichlorosilane and releasing hydrogen.","inputs":["hydrochloric-acid"],"spec":"about 300 °C"},{"name":"Condense the vapors","process":"chill","text":"The hot mix leaving the reactor is cooled until the chlorosilanes turn to liquid. The hydrogen stays a gas and is drawn off.","inputs":[]},{"name":"Distill away the by-products","process":"refine","text":"Silicon tetrachloride, hexachlorodisilane and dichlorosilane are the main by-products. Distillation separates the trichlorosilane from them.","inputs":[]},{"name":"Store it dry","process":"fill","text":"The colorless, volatile liquid is kept in sealed tanks away from moisture, because water breaks it down.","inputs":[]}],"facts":["Purified trichlorosilane is the principal precursor to ultrapure silicon in the semiconductor industry.","In water it rapidly decomposes to a siloxane polymer and gives off hydrochloric acid.","Silicon refined through purified trichlorosilane can end up with impurity levels below one part per billion."],"where":[],"whereNote":null,"sources":[{"title":"Trichlorosilane","url":"https://en.wikipedia.org/wiki/Trichlorosilane"},{"title":"Siemens process","url":"https://en.wikipedia.org/wiki/Siemens_process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"trona","name":"Trona","kind":"raw","category":"ground","title":"How trona is mined","url":"https://assemblyline.org/make/trona","stations":4,"upstream":0,"downstream":177,"depth":0,"dek":"Under a Wyoming interstate, one mine's tunnels add up to more roadway than the city of San Francisco has.","answer":"Trona lies in thick beds far beneath Wyoming, left by ancient lakes. Machines bore rooms through the seam and leave pillars to hold up the roof. Belts carry the ore miles to a shaft, skips hoist it to the surface, and crushers reduce it to half-inch pieces for a plant that turns them into soda ash.","aka":["natron","sodium sesquicarbonate"],"inputs":[],"uses":["soda-ash","baking-soda"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["soda-ash","baking-soda","detergent","fiberglass","lithium-carbonate","chromium","glass","window-glass","glass-bottle","smartphone-glass","marble-toy","instant-noodles","stained-glass","vanadium","pretzel","sparkling-water","frozen-pizza","bagel","crackers","cake-mix","fire-extinguisher","printed-circuit-board","wind-turbine","surfboard","ski","snowboard","fishing-rod","kite","roof-shingle","vinyl-floor","canoe","sailboat","umbrella","lithium-ion-cell","hip-implant","hard-drive","stainless-steel","safety-pin","razor-blade","faucet","turbine-blade","toaster","ice-skates","dumbbell","stent","wrench","nichrome","leather","thermometer","lcd-screen","oled-screen","camera-sensor","solar-panel","microwave-oven","wristwatch","optical-fiber","eyeglass-lens","sunglasses","light-bulb","indium-tin-oxide","glass-jar","water-heater","bowling-ball","snow-globe","floor-tile","neon-sign","smartwatch","e-reader","mirror","skyscraper","windshield","double-glazed-window","nail-polish","perfume","penicillin","insulin","vaccine","ketchup","cola","beer","wine","champagne","whiskey","vodka","gin","rum","tequila","sake","hard-cider","hot-sauce","soda","root-beer","kombucha","tonic-water","bourbon","scotch","cognac","mezcal","mead","port-wine","prosecco","non-alcoholic-beer","smartphone","hearing-aid","pacemaker","led-bulb","ev-battery","laptop","television","solid-state-drive","computer-keyboard","computer-mouse","washing-machine","drone","satellite","car","electric-car","airbag","airplane","rocket","locomotive","motorcycle","elevator","blender","ceiling-fan","treadmill","pinball-machine","smoke-detector","wireless-earbuds","phone-charger","digital-camera","game-console","wifi-router","inkjet-printer","graphics-card","remote-control","electric-toothbrush","syringe","electric-kettle","kitchen-knife","fork","fountain-pen","thermos","water-bottle","pressure-cooker","dishwasher","golf-club","asthma-inhaler","subway-train","jet-engine","baseball","basketball","tennis-racket","football","saxophone","winter-gloves","leather-belt","handbag","wallet","hiking-boots","high-heels","leather-shoe","eyeglass-frame","mustard","salsa","pickles","sauerkraut","jam","hazelnut-spread","aluminum-window-frame","shampoo","deodorant","air-freshener","dish-soap","hairspray","foundation-makeup","mayonnaise"],"steps":[{"name":"Drive the entries","process":"mine","text":"Continuous miners cut rectangular entries 18 feet wide to open up new ground, leaving standard pillars of 80 by 120 feet. The seam at one Green River mine sits about 1,500 feet down and runs 9 to 12 feet thick.","inputs":[]},{"name":"Bore the rooms","process":"mine","text":"Twin-rotor borer miners take about 80% of production at that mine, chewing oval, smooth-walled rooms about 8 feet high at 30 inches a minute. A flexible conveyor train follows each machine around curves and breaks up lumps.","inputs":[]},{"name":"Belt and hoist it","process":"mine","text":"A main belt system in 12 segments runs the ore 13 miles to an underground storage bunker at the shaft. From there it rides 22-ton skips to the surface.","inputs":[]},{"name":"Crush to half an inch","process":"crush","text":"A horizontal shaft impactor and then a roll sizer reduce the ore to under 0.5 inch. It then heads to the calciner, the first step of the soda ash plant.","inputs":[],"spec":"minus 0.5 in."}],"facts":["Most countries make sodium carbonate by the Solvay process, but in the United States mined trona is the primary source.","The name trona came to English from Swedish or Spanish and traces back through Arabic to the Greek word for natron.","Room-and-pillar mining of Wyoming trona recovers an average 55% of the bed, against 30% for solution mining."],"where":[],"whereNote":null,"sources":[{"title":"Progress in the Patch (E&MJ)","url":"https://www.e-mj.com/features/progress-in-the-patch/"},{"title":"Trona","url":"https://en.wikipedia.org/wiki/Trona"},{"title":"Evaporite","url":"https://en.wikipedia.org/wiki/Evaporite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"trumpet","name":"Trumpet","kind":"product","category":"play","title":"How trumpets are made","url":"https://assemblyline.org/make/trumpet","stations":7,"upstream":45,"downstream":0,"depth":6,"dek":"A trumpet is about two meters of brass tube bent twice, and three valves switch in extra lengths of it.","answer":"A trumpet is made of brass tubing. Sheet brass is rolled into tubes and drawn smooth, and a flared bell is hammered or spun from a flat disc. The tubes are bent, soldered to piston valves and a bell, then polished and lacquered. A player's buzzing lips set the air column inside vibrating.","aka":["Bb trumpet","brass trumpet"],"inputs":["brass","nickel","solder","silver","lacquer"],"uses":[],"grounds":["nickel-ore","silver-ore","lead-ore","zinc-ore","copper-ore","water","air","tin-ore","crude-oil","coal","sulfur","limestone","corn","sugarcane","bauxite","natural-gas","rock-salt","sugar-beet"],"upstreamSlugs":["brass","nickel","solder","silver","lacquer","copper","zinc","lead","tin","aluminum","nickel-ore","sulfuric-acid","silver-ore","lead-ore","zinc-ore","copper-ore","lime","ethanol","acrylic","water","oxygen","air","coke","tin-ore","crude-oil","coal","petroleum-coke","alumina","sulfur","limestone","corn","sugarcane","yeast","ethylene","propylene","ammonia","methanol","bauxite","caustic-soda","molasses","naphtha","natural-gas","rock-salt","sugar-beet","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Draw the brass tubing","process":"draw","text":"Flat brass is rolled into tubes, seamed, and pulled over a mandrel to make them smooth and uniform. Different leadpipes and tuning slides need different diameters.","inputs":["brass"]},{"name":"Form the bell","process":"stamp","text":"A flat disc of brass is shaped over a form into a long, flared bell. The shape of the bell is what makes the missing overtones audible.","inputs":["brass"]},{"name":"Bend the tubes","process":"mold","text":"Tubes are filled to keep them from kinking, bent round formers and cut to fit. Trumpet tubing has been bent twice into a rounded oblong shape since the late 15th century.","inputs":[]},{"name":"Machine the valves","process":"machine","text":"Valve casings and pistons are machined from brass and nickel parts. The three pistons fit so closely that air cannot leak between them.","inputs":["brass","nickel"]},{"name":"Solder the assembly","process":"weld","text":"Bell, tubes, valve block, braces and slides are soldered into one instrument.","inputs":["solder"]},{"name":"Polish and lacquer","process":"coat","text":"The horn is buffed to a mirror shine and then coated with clear lacquer or plated with silver.","inputs":["silver","lacquer"]},{"name":"Test and tune","process":"inspect","text":"A tester plays the instrument, and slides are adjusted. First and third valves may carry slides the player can pull out to correct pitch.","inputs":[]}],"facts":["Three valves make eight possible combinations but only seven different tubing lengths, since the third valve alone matches the 1-2 combination.","The first valve lowers pitch by a whole step, the second by a half step, and the third by a step and a half.","The trumpet's cylindrical bore distinguishes it from the cornet, which has a conical bore."],"where":[],"whereNote":null,"sources":[{"title":"Trumpet","url":"https://en.wikipedia.org/wiki/Trumpet"},{"title":"Brass instrument","url":"https://en.wikipedia.org/wiki/Brass_instrument"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tuna-fish","name":"Tuna","kind":"raw","category":"farm","title":"How tuna is caught","url":"https://assemblyline.org/make/tuna-fish","stations":3,"upstream":0,"downstream":1,"depth":0,"dek":"Yellowfin tuna can swim at up to 75 km/h, among the fastest fish in the open sea.","answer":"Most commercial tuna are caught at sea with purse-seine nets, which have become the dominant gear. A boat encircles a school with a long net, then pulls the bottom closed like a drawstring purse. Longlines are the other major method, and older hook-and-line fishing once took most of the catch.","aka":["tuna fishing","tuna fishery","yellowfin","skipjack","bluefin"],"inputs":[],"uses":["canned-tuna"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["canned-tuna"],"steps":[{"name":"Find the school","process":"harvest","text":"Tuna live in tropical and temperate seas and move widely. Fleets search for schools of the five principal market species, which include yellowfin, bigeye and bluefin tuna.","inputs":[]},{"name":"Encircle it with a net","process":"harvest","text":"A purse seine is a net that hangs vertically in the water, with weights holding the bottom edge down and floats on top. A boat sets it around the school, and the net encloses the fish rather than snaring them as a gillnet would.","inputs":[]},{"name":"Haul the catch aboard","process":"harvest","text":"The net is closed and drawn in, and the tuna are brought aboard the vessel. Longline boats set long lines of baited hooks as an alternative.","inputs":[]}],"facts":["Tuna keep a core body temperature of 25 to 33 °C, warmer than the sea around them.","The Atlantic bluefin can reach 4.6 m in length and 684 kg in weight.","Annual world catches rose from about 300 thousand tons in 1940 to more than 4 million tons in the years before the report, as purse seines became the main gear."],"where":[{"place":"Pacific Ocean","share":"about 68% of the catch"},{"place":"Indian Ocean","share":"about 22% of the catch"}],"whereNote":"Share of the global catch of the five principal market tunas, from a report based on 2007 catches.","sources":[{"title":"Tuna","url":"https://en.wikipedia.org/wiki/Tuna"},{"title":"Purse seine","url":"https://en.wikipedia.org/wiki/Purse_seine"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tungsten","name":"Tungsten","kind":"material","category":"metals","title":"How tungsten is made","url":"https://assemblyline.org/make/tungsten","stations":6,"upstream":4,"downstream":5,"depth":2,"dek":"Tungsten melts at 3,422 °C, hotter than any other metal, so it is never melted and is pressed from powder.","answer":"Tungsten ore is crushed and concentrated, then dissolved and precipitated with ammonia to make a tungsten salt. The dried powder is heated into tungsten oxide and reduced with hydrogen to a gray metal powder. Since the metal's melting point is too high for casting, the powder is pressed and sintered into solid bars.","aka":["wolfram","tungsten metal"],"inputs":["tungsten-ore","hydrogen"],"uses":["light-bulb","tungsten-carbide","drill-bit"],"grounds":["tungsten-ore","natural-gas","water"],"upstreamSlugs":["tungsten-ore","hydrogen","natural-gas","water"],"downstreamSlugs":["light-bulb","tungsten-carbide","drill-bit","ballpoint-pen","saw-blade"],"steps":[{"name":"Crush and concentrate","process":"crush","text":"The ores, wolframite and scheelite, are rarely more than 1.5 percent tungsten oxide. They are crushed, then scheelite is floated and wolframite is separated by gravity and magnets.","inputs":["tungsten-ore"]},{"name":"Dissolve it as tungstate","process":"react","text":"The concentrate is dissolved into a water solution of tungstate. Ammonia is added, and a tungsten salt precipitates out and is filtered.","inputs":[]},{"name":"Dry it to an oxide","process":"dry","text":"The precipitate is dried at 600 °C, and the result is a fairly pure tungsten oxide powder.","inputs":[],"spec":"600 °C"},{"name":"Reduce it with hydrogen","process":"react","text":"The oxide is heated in a stream of hydrogen, which takes away the oxygen as water and leaves tungsten powder. Carbon is not used, because heating with coal makes tungsten carbide instead.","inputs":["hydrogen"]},{"name":"Press and sinter the powder","process":"press","text":"Tungsten melts at 3,422 °C, the highest of any metal. So the powder is pressed into bars and sintered, meaning heated until the grains fuse without liquefying. The product is somewhat porous.","inputs":[]},{"name":"Work it into wire and rod","process":"draw","text":"Once purified, tungsten can be forged, drawn, rolled or extruded, though raw tungsten is brittle and hard to work. Drawn wire becomes light bulb filaments.","inputs":[]}],"facts":["Between 60 and 70 percent of the world's tungsten goes into cemented carbide, which is used for cutting tools, drills and wear parts.","The name means 'heavy stone' in Swedish, and wolfram, the name used in German, comes from the mineral wolframite."],"where":[{"place":"China","share":"67,000 tonnes"},{"place":"Vietnam","share":"3,000 tonnes"},{"place":"Kazakhstan","share":"2,400 tonnes"}],"whereNote":"2025, tungsten content of mined material, out of 85,000 tonnes worldwide.","sources":[{"title":"Tungsten","url":"https://en.wikipedia.org/wiki/Tungsten"},{"title":"Froth flotation","url":"https://en.wikipedia.org/wiki/Froth_flotation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tungsten-carbide","name":"Tungsten carbide","kind":"material","category":"metals","title":"How tungsten carbide is made","url":"https://assemblyline.org/make/tungsten-carbide","stations":5,"upstream":21,"downstream":2,"depth":5,"dek":"Tungsten carbide is twice as dense as steel and about as hard as corundum, the mineral in sapphire.","answer":"Tungsten carbide is made by reacting tungsten powder with carbon at furnace temperatures between 1,400 and 2,000 °C. The gray powder is mixed with a metal binder, usually cobalt, pressed into shape and sintered until the binder melts and locks the grains together. Only diamond-class abrasives can finish it.","aka":["carbide","WC","cemented carbide"],"inputs":["tungsten","carbon-black","cobalt"],"uses":["ballpoint-pen","saw-blade"],"grounds":["tungsten-ore","crude-oil","air","water","cobalt-ore","natural-gas","sulfur","coal","bauxite","rock-salt","limestone"],"upstreamSlugs":["tungsten","carbon-black","cobalt","tungsten-ore","hydrogen","crude-oil","air","water","cobalt-ore","sulfuric-acid","aluminum","natural-gas","sulfur","coal","petroleum-coke","alumina","bauxite","caustic-soda","lime","rock-salt","limestone"],"downstreamSlugs":["ballpoint-pen","saw-blade"],"steps":[{"name":"Cook tungsten with carbon","process":"react","text":"Tungsten metal powder and carbon are heated together in a furnace. They combine atom for atom to give a fine gray powder.","inputs":["tungsten","carbon-black"],"spec":"1,400 to 2,000 °C"},{"name":"Mill in a cobalt binder","process":"mix","text":"The carbide powder is blended with a binder metal. Cobalt has been the standard binder since cemented carbide first reached the market.","inputs":["cobalt"]},{"name":"Press the powder to shape","process":"press","text":"Dies pack the powder into the rough shape of a tool tip or insert. The pressed piece is fragile and oversized because it will shrink.","inputs":[]},{"name":"Sinter until the binder melts","process":"fire","text":"The part is heated until the binder turns liquid while the carbide grains stay solid. Grains pull together into a dense, tough composite.","inputs":[]},{"name":"Grind to final size","process":"grind","text":"Only abrasives as hard as cubic boron nitride or diamond can polish and finish tungsten carbide.","inputs":[]}],"facts":["Tungsten carbide is about three times as stiff as steel and twice as dense.","Henri Moissan first made tungsten carbide powder in 1893.","WIDIA, an early trade name for cemented carbide, comes from the German for like diamond."],"where":[],"whereNote":null,"sources":[{"title":"Tungsten carbide","url":"https://en.wikipedia.org/wiki/Tungsten_carbide"},{"title":"Cemented carbide","url":"https://en.wikipedia.org/wiki/Cemented_carbide"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"tungsten-ore","name":"Tungsten ore","kind":"raw","category":"ground","title":"How tungsten ore is mined","url":"https://assemblyline.org/make/tungsten-ore","stations":4,"upstream":0,"downstream":6,"depth":0,"dek":"Scheelite, one of tungsten's two main ores, glows bright blue under ultraviolet light.","answer":"Tungsten ore is sorted mainly by weight. Wolframite and scheelite sit in deposits around granite, reached by open pits in Australia and Canada but usually by underground mines elsewhere. Mills crush the rock and let gravity separation pull out the dense tungsten minerals. Scheelite ground very fine goes to flotation, and leaching, roasting or magnets can clean up what remains.","aka":["wolframite","scheelite"],"inputs":[],"uses":["tungsten"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["tungsten","light-bulb","tungsten-carbide","drill-bit","ballpoint-pen","saw-blade"],"steps":[{"name":"Work the quartz veins","process":"mine","text":"Wolframite forms in quartz veins and pegmatites near granite. China's high-grade veins outcrop in many separate places and suit small operations, while most mines elsewhere must go underground.","inputs":[]},{"name":"Crush the vein rock","process":"crush","text":"Crushing is the first step in beneficiation, breaking the rock so the dark, heavy tungsten minerals come loose.","inputs":[]},{"name":"Sort by weight","process":"separate","text":"Gravity concentration lets the dense tungsten minerals part from lighter waste. This is the standard treatment for tungsten ores.","inputs":[]},{"name":"Float the fine scheelite","process":"separate","text":"Scheelite that must be ground fine to free it goes to flotation. Leaching, roasting, magnets or high-tension separators are added when the concentrate needs more cleaning, and it then moves on to a chemical plant.","inputs":[]}],"facts":["No metal melts at a higher temperature than tungsten, at 3,422 °C.","Wolframite takes its name from an old German word for tungsten, wolf rahm, which Agricola rendered in Latin as wolf's froth.","Chemists identified tungsten as its own element in 1781 and first isolated the metal in 1783."],"where":[{"place":"China","share":"71,000 metric tons"},{"place":"Vietnam","share":"4,800 metric tons"},{"place":"Russia","share":"2,300 metric tons"},{"place":"Bolivia","share":"1,400 metric tons"},{"place":"Rwanda","share":"1,100 metric tons"}],"whereNote":"Tungsten mined in 2022, out of an estimated 84,000 metric tons worldwide.","sources":[{"title":"Tungsten processing","url":"https://www.britannica.com/technology/tungsten-processing"},{"title":"Tungsten","url":"https://en.wikipedia.org/wiki/Tungsten"},{"title":"Wolframite","url":"https://en.wikipedia.org/wiki/Wolframite"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"turbine-blade","name":"Turbine blade","kind":"product","category":"machines","title":"How turbine blades are made","url":"https://assemblyline.org/make/turbine-blade","stations":8,"upstream":38,"downstream":2,"depth":6,"dek":"Cooled turbine blades run in gas near 1,370 °C, so each is cast around a ceramic maze of cooling channels.","answer":"A turbine blade is cast from nickel superalloy by the lost-wax method. A wax copy of the blade, wrapped around a ceramic core that will leave cooling passages, is dipped in ceramic to build a shell. The wax is melted out, metal is poured in, and the blade is finished, drilled with tiny holes and coated.","aka":["turbine bucket","gas turbine blade"],"inputs":["paraffin-wax","ceramic","nickel","cobalt","chromium"],"uses":["jet-engine"],"grounds":["crude-oil","clay","kaolin","feldspar","quartz","nickel-ore","cobalt-ore","chromite","limestone","air","water","natural-gas","sulfur","coal","rock-salt","trona","bauxite","corn","sugarcane","sugar-beet"],"upstreamSlugs":["paraffin-wax","ceramic","nickel","cobalt","chromium","crude-oil","hydrogen","clay","kaolin","feldspar","quartz","nickel-ore","sulfuric-acid","cobalt-ore","aluminum","chromite","coke","soda-ash","limestone","air","water","natural-gas","sulfur","coal","petroleum-coke","alumina","rock-salt","ammonia","carbon-dioxide","lime","trona","bauxite","caustic-soda","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["jet-engine","airplane"],"steps":[{"name":"Inject a wax blade","process":"mold","text":"Molten wax is injected into a metal die in the exact shape of the blade. If the blade is hollow, a ceramic core in the shape of its cooling passages is placed in the die first.","inputs":["paraffin-wax"]},{"name":"Dip into a ceramic shell","process":"coat","text":"Wax blades are fixed onto a central wax stalk and dipped over and over into ceramic slurry and sand. The layers dry into a hard, heat-resistant shell.","inputs":["ceramic"]},{"name":"Melt out the wax","process":"melt","text":"Steam or heat drains the wax from the shell, leaving a hollow mold of the blade. The wax can often be reused.","inputs":[]},{"name":"Pour in the superalloy","process":"cast","text":"Superalloy based on nickel is melted in a vacuum and poured into the hot shell. Nickel keeps its strength at temperatures where steel would soften.","inputs":["nickel","cobalt","chromium"]},{"name":"Grow a single crystal","process":"grow","text":"In the best blades the metal is cooled slowly so that it solidifies as one single crystal. With no grain boundaries across the blade, it creeps far less at high temperatures.","inputs":[]},{"name":"Break the shell and drill cooling holes","process":"machine","text":"The shell is knocked off and the ceramic core is dissolved away. Lasers or electrical discharge then drill tiny holes through which cool air will pour over the blade skin.","inputs":[]},{"name":"Add a thermal barrier coating","process":"coat","text":"A thin layer of ceramic coating is applied to insulate the metal from the hot gas.","inputs":["ceramic"]},{"name":"Scan every blade","process":"inspect","text":"Blades are checked for hidden flaws, wall thickness and airflow through the cooling holes. One blade that fails can wreck an engine.","inputs":[]}],"facts":["Military engines like the Snecma M88 can see turbine temperatures of 1,590 °C.","Ceramic matrix composites can withstand temperatures 200 to 300 °F higher than superalloys."],"where":[],"whereNote":null,"sources":[{"title":"Turbine blade","url":"https://en.wikipedia.org/wiki/Turbine_blade"},{"title":"Investment casting","url":"https://en.wikipedia.org/wiki/Investment_casting"},{"title":"Thermal barrier coating","url":"https://en.wikipedia.org/wiki/Thermal_barrier_coating"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"ukulele","name":"Ukulele","kind":"product","category":"play","title":"How ukuleles are made","url":"https://assemblyline.org/make/ukulele","stations":9,"upstream":37,"downstream":0,"depth":8,"dek":"A ukulele side gets its curve from one quick dunk in water and a short trip over a gas-fired mold.","answer":"A ukulele is a small box of thin wood. Rough lumber is resawn into tops, backs and sides. The sides are dunked in water and bent on heated aluminum molds, glued to blocks and linings, then closed with a braced top and a back. A neck is spliced on, the body is sanded, sprayed with lacquer, and strung with nylon.","aka":["uke","ukelele"],"inputs":["lumber","adhesive","lacquer","nylon"],"uses":[],"grounds":["timber","water","crude-oil","corn","sugarcane","air","natural-gas","sulfur","rock-salt","coal","sugar-beet"],"upstreamSlugs":["lumber","adhesive","lacquer","nylon","timber","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","ethanol","benzene","nitric-acid","ammonia","ethylene","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","crude-oil","hydrogen","corn","sugarcane","yeast","naphtha","toluene","air","natural-gas","sulfur","rock-salt","molasses","coal","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Age the koa","process":"dry","text":"At Kamaka in Honolulu, koa lumber is stored for about four years before it becomes ukuleles. Koa is a native Hawaiian wood similar to mahogany.","inputs":["lumber"]},{"name":"Resaw the parts","process":"cut","text":"Rough lumber is resawn into thin pieces for the sides, top and back, and into neck blanks.","inputs":[]},{"name":"Bend the sides","process":"mold","text":"Each side is dunked in water briefly and laid on a gas-fired aluminum bending mold. A quick trip on the mold sets the curve.","inputs":[]},{"name":"Build the rim","process":"assemble","text":"End and neck blocks are chosen and glued in, with linings that give extra gluing surface for the top and back. The finished rims sit in molds or frames to hold their shape until the top and back are ready.","inputs":["adhesive"]},{"name":"Brace and close the box","process":"assemble","text":"The top is braced and contoured, then the top and back are glued to the rim in rotating clamp fixtures. Softwood tops and hardwood backs are the usual pairing.","inputs":["adhesive"]},{"name":"Fit the neck","process":"assemble","text":"A simple spline joins the neck to the body. That is enough for the low tension of nylon strings.","inputs":["adhesive"]},{"name":"Sand and tap-test","process":"grind","text":"The assembled instrument gets a pass with an orbital sander. A craftsman then taps it and listens to decide whether it goes into finishing.","inputs":[]},{"name":"Spray the lacquer","process":"coat","text":"Nitrocellulose lacquer is the finish of choice. Ukuleles get several coats with sanding between each one.","inputs":["lacquer"]},{"name":"String and set up","process":"assemble","text":"Bridges are fitted and each instrument is set up by a single craftsman. Ukuleles generally have four nylon strings.","inputs":["nylon"]}],"facts":["Seventeen craftsmen work full time making Kamaka ukuleles, and the instruments move through the shop in batches.","The ukulele was developed in the 1880s from small Portuguese guitar-like instruments brought to Hawaii.","The word ukulele roughly translates from Hawaiian as jumping flea."],"where":[],"whereNote":null,"sources":[{"title":"FRETS.COM Field Trip: The Ukulele at Kamaka","url":"https://www.frets.com/FretsPages/Features/Kamaka/kamaka.html"},{"title":"Ukulele","url":"https://en.wikipedia.org/wiki/Ukulele"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"umbrella","name":"Umbrella","kind":"product","category":"textiles","title":"How umbrellas are made","url":"https://assemblyline.org/make/umbrella","stations":8,"upstream":59,"downstream":0,"depth":8,"dek":"A collapsible umbrella is a fabric dome on a frame of ribs, and a similar one was reportedly designed in 21 AD.","answer":"A factory checks incoming ribs and fabric, cuts the cloth into strips and then triangles called gores, and prints the flat pieces. Sewing machines join 8 gores into a dome. Another team builds the shaft, ribs and runner. The canopy is then attached by sewing or gluing its points to the rib tips, the handle goes on, and each umbrella is opened and closed to test it.","aka":["parasol","rain umbrella","folding umbrella"],"inputs":["polyester","ink","thread","fiberglass","plastic","rubber","epoxy"],"uses":[],"grounds":["water","silica-sand","limestone","natural-gas","natural-latex","sulfur","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","corn","sugarcane","rock-salt","trona","coal","sugar-beet"],"upstreamSlugs":["polyester","ink","thread","fiberglass","plastic","rubber","epoxy","pet-plastic","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","silica-sand","limestone","soda-ash","naphtha","natural-gas","ethylene","propylene","natural-latex","synthetic-rubber","sulfur","phenol","acetone","chlorine","caustic-soda","p-xylene","ethylene-glycol","soybeans","rapeseed","hexane","clay","formaldehyde","crude-oil","air","titanium-ore","coke","oxygen","sulfuric-acid","iron-ore","corn","sugarcane","yeast","rock-salt","ammonia","carbon-dioxide","lime","trona","hydrogen","benzene","styrene","methanol","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Check ribs and fabric","process":"inspect","text":"Fiberglass ribs are bent to see that they do not snap, and fabric rolls over a light table to reveal knots or uneven coating. Failures go back to the mill.","inputs":["polyester"]},{"name":"Cut the gores","process":"cut","text":"The roll is cut into rectangular strips, then into triangles called gores. Small stacks and digital templates keep every panel the same size.","inputs":[]},{"name":"Print the flat panels","process":"print","text":"Designs go on before sewing, by screen printing for simple logos and digital printing for complex art.","inputs":["ink"]},{"name":"Sew the dome","process":"sew","text":"Workers stitch 8 gores together into a canopy. A waterproof washer and tight stitching at the top center keep rain from running down the shaft.","inputs":["thread"]},{"name":"Build the frame","process":"assemble","text":"A second team joins shaft, ribs and runner. On golf models the fiberglass ribs lock to the shaft through a high-impact plastic notch.","inputs":["fiberglass","plastic"]},{"name":"Join canopy to frame","process":"sew","text":"Fabric is attached at each rib. Cheaper lines glue the tips on, while better ones sew them by machine so they cannot pop off when the glue dries.","inputs":["thread"]},{"name":"Fix on the handle","process":"assemble","text":"A wood, rubber or plastic handle is fixed to the shaft with epoxy or screws so it will not twist loose.","inputs":["rubber","epoxy"]},{"name":"Test and pack","process":"inspect","text":"Each umbrella is opened and closed 3 times and its loose threads are trimmed. Random samples are blasted with high-pressure water before boxing.","inputs":[]}],"facts":["The first lightweight folding umbrella in Europe was introduced in 1710 by a Paris merchant named Jean Marius, and it weighed less than one kilogram.","Umbrellas were rented out in Paris in 1769, and the rental umbrellas were made of oiled green silk.","The oldest known umbrella appears in the archaeological record around 2310 BC, on a victory stele of Sargon of Akkad."],"where":[],"whereNote":null,"sources":[{"title":"HF Umbrella: Umbrella manufacturing process","url":"https://hfumbrella.com/umbrella-manufacturing-process-2"},{"title":"Umbrella","url":"https://en.wikipedia.org/wiki/Umbrella"},{"title":"Sewing thread","url":"https://en.wikipedia.org/wiki/Sewing_thread"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"underwear","name":"Underwear","kind":"product","category":"textiles","title":"How underwear is made","url":"https://assemblyline.org/make/underwear","stations":9,"upstream":52,"downstream":0,"depth":8,"dek":"On a one-piece knitting line, two pairs of underwear come out as one tube, then an overlock machine splits them.","answer":"Cut-and-sew remains the widest route: knit cloth is dyed, dried, stacked and sliced into panels, then stitched together and joined to a separately knit elastic waistband. One-piece knit styles skip most of that, since a circular knitting machine makes the garment shape directly and only the crotch and leg openings need an overlock stitch. Tags and printed labels go on near the end.","aka":["briefs","boxers","boxer briefs","underpants"],"inputs":["cotton-yarn","nylon","polyurethane","spandex","thread","ink"],"uses":[],"grounds":["raw-cotton","water","air","natural-gas","crude-oil","rock-salt","soybeans","rapeseed","clay","titanium-ore","iron-ore","sulfur","corn","sugarcane","coal","limestone","sugar-beet"],"upstreamSlugs":["cotton-yarn","nylon","polyurethane","spandex","thread","ink","raw-cotton","benzene","nitric-acid","ammonia","propylene","chlorine","water","formaldehyde","ethylene-glycol","polyester","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","naphtha","hydrogen","toluene","air","natural-gas","crude-oil","rock-salt","sulfuric-acid","methanol","ethylene","oxygen","carbon-dioxide","pet-plastic","soybeans","rapeseed","hexane","clay","phenol","titanium-ore","coke","iron-ore","sulfur","corn","sugarcane","yeast","coal","limestone","p-xylene","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Knit the cloth","process":"weave","text":"Yarn goes onto knitting machines and comes off as stretchy cloth, with elastic fiber running through it. A one-piece knit line runs high-speed circular machines instead, and one attendant can watch 5 or 6 of them.","inputs":["cotton-yarn","nylon","polyurethane","spandex"]},{"name":"Dye and dry","process":"dye","text":"The cloth is dyed and dried before it moves to the sewing unit. One-piece tubes are knit from white yarn and take their color in a dyeing machine afterward.","inputs":[]},{"name":"Cut the panels","process":"cut","text":"Industrial fabric cutters slice panels for each size out of the cloth. One-piece production drops this step altogether, which also saves fabric.","inputs":[]},{"name":"Knit the waistbands","process":"weave","text":"Elastic waistbands are knit as a separate job while the panels are prepared. A one-piece tube builds a two-layer waistband straight into the knit.","inputs":["polyurethane","spandex"]},{"name":"Stitch the panels","process":"sew","text":"Production lines sew the panels into a garment from the approved pattern, with checks along the way. A one-piece pair needs far less: an overlock machine separates the two pairs in a tube, closes the crotch and finishes the leg openings.","inputs":["thread"]},{"name":"Join the waistband","process":"sew","text":"A sewing machine fastens the sewn body to its waistband. Stray threads are trimmed off once the garment is together.","inputs":["thread"]},{"name":"Print and tag","process":"print","text":"Fabric printers add any pattern, and each pair gets its brand and size. One such factory pad-prints size, care and fiber details inside the back, a method that needs no drying or curing.","inputs":["ink"]},{"name":"Check the stretch","process":"inspect","text":"Inspectors look at stitching, elasticity, seam strength and fit. One-piece garments are also checked under a light table after dyeing, so that knitting and color faults never reach the sewing station.","inputs":[]},{"name":"Pack in combos","process":"package","text":"Finished pairs are tagged and packed for shipping. One factory bundles 3 to 5 pairs of the same size in different colors.","inputs":[]}],"facts":["A one-piece knit line can take underwear from knitting to packing within a single day.","Underwear makers often set higher minimum orders than T-shirt makers, because each pair uses so little fabric.","Boxer shorts take their name from the loose elastic-waist trunks designed for boxers in 1925, who needed unrestricted leg movement."],"where":[],"whereNote":null,"sources":[{"title":"Seamless Underwear (Panty) Manufacturing Process, Online Clothing Study","url":"https://onlineclothingstudy.com/2020/08/seamless-underwear-panty-manufacturing.html"},{"title":"The process of making underwear, Jockey Philippines","url":"https://www.jockey.com.ph/blogs/news/the-process-of-making-underwear"},{"title":"Underwear Manufacturing, Thygesen Textile Vietnam","url":"https://thygesenapparel.com/blog/underwear-manufacturing-process"},{"title":"Boxer shorts","url":"https://en.wikipedia.org/wiki/Boxer_shorts"},{"title":"Spandex","url":"https://en.wikipedia.org/wiki/Spandex"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"usb-cable","name":"USB cable","kind":"product","category":"electronics","title":"How USB cables are made","url":"https://assemblyline.org/make/usb-cable","stations":9,"upstream":77,"downstream":0,"depth":9,"dek":"One factory turns out 22,000 to 25,000 USB cables a day, and fewer than 1 percent fail inspection.","answer":"A USB cable has fine copper wires, some for power and some for data, each coated in plastic and wrapped in a foil and braid shield under a jacket. Factories cut this raw cable to length, strip the ends, dip them in tin and solder them to the connector by color. Plastic is molded over the joint in two stages, with electrical tests after each.","aka":["USB-C cable","charging cable","data cable"],"inputs":["copper-wire","polyethylene","pvc","aluminum-foil","brass","steel","nickel","gold","solder","tin","microchip","abs-plastic"],"uses":[],"grounds":["water","nickel-ore","gold-ore","tin-ore","air","copper-ore","natural-gas","rock-salt","iron-ore","sulfur","crude-oil","coal","zinc-ore","lead-ore","limestone","dolomite","manganese-ore","silver-ore","quartz","titanium-ore","bauxite","timber"],"upstreamSlugs":["copper-wire","polyethylene","pvc","aluminum-foil","brass","steel","nickel","gold","solder","tin","microchip","abs-plastic","copper","ethylene","chlorine","water","pigment","plasticizer","aluminum","zinc","lead","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","nickel-ore","sulfuric-acid","gold-ore","silver","tin-ore","coke","silicon-wafer","photoresist","naphtha","propylene","ammonia","air","benzene","styrene","copper-ore","natural-gas","rock-salt","iron-ore","titanium-dioxide","carbon-black","sulfur","crude-oil","coal","petroleum-coke","alumina","zinc-ore","lead-ore","limestone","dolomite","silicon","propane","manganese-ore","silver-ore","polysilicon","quartz","phenolic-resin","hydrogen","toluene","titanium-ore","bauxite","caustic-soda","charcoal","timber","hydrochloric-acid","trichlorosilane","nitrogen","phenol","formaldehyde","methanol"],"downstreamSlugs":[],"steps":[{"name":"Draw the copper wire","process":"draw","text":"Copper rod is pulled through a series of ever-smaller dies until it is a thin strand. Several strands are twisted into one flexible conductor.","inputs":["copper-wire"]},{"name":"Insulate each conductor","process":"extrude","text":"Each strand passes through an extruder that coats it in a thin layer of plastic. Different colors mark power, ground and the data pairs.","inputs":["polyethylene","pvc"]},{"name":"Twist and shield the pairs","process":"assemble","text":"Data wires are twisted in pairs to cancel interference. A wrap of aluminum foil and a braided shield go around the bundle to stop signals from leaking in or out.","inputs":["aluminum-foil","copper-wire"]},{"name":"Jacket the cable","process":"extrude","text":"The shielded bundle is fed through a second extruder that coats it in a tough outer jacket. The finished raw cable is wound on large spools.","inputs":["pvc","polyethylene"]},{"name":"Stamp and plate the connectors","process":"stamp","text":"Presses punch metal contacts and shells out of sheet brass or steel. The contacts are electroplated with nickel and a thin gold layer to resist corrosion.","inputs":["brass","steel","nickel","gold"]},{"name":"Cut and strip the ends","process":"cut","text":"Raw cable is cut to lengths such as 1 meter or 2 meters. The outer jacket comes off, the braid is folded back, the foil is removed, and the inner jacket is stripped to bare the conductors.","inputs":[]},{"name":"Tin and solder the wires","process":"weld","text":"Each conductor end is dipped in flux and then in molten tin, and soldered to the matching connector pin by wire color. Some USB-C plugs also carry a small chip that tells the device what the cable can do.","inputs":["solder","tin","microchip"]},{"name":"Mold the inner shell","process":"mold","text":"Plastic is molded over the soldered joint to hold the wires in place, and an iron shell goes on top. The cable gets its first electrical test here.","inputs":["abs-plastic"]},{"name":"Mold the outer plug","process":"mold","text":"A second molding forms the outer plug and strain relief. A final electrical test checks every line before packing.","inputs":["abs-plastic"]}],"facts":["The USB-C connector can carry up to 240 watts of power.","Nearly all bad cables caught early at one factory can be fixed in-house, which keeps waste down."],"where":[],"whereNote":null,"sources":[{"title":"USB","url":"https://en.wikipedia.org/wiki/USB"},{"title":"The manufacturing process of USB cables (STC Cable)","url":"https://www.stc-cable.com/news/the-manufacturing-process-of-usb-cables"},{"title":"Why USB Type-C isn't in more cases (Gamers Nexus)","url":"https://gamersnexus.net/guides/3453-why-usb-type-c-isnt-more-cases"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"utility-pole","name":"Utility pole","kind":"product","category":"wood-paper","title":"How wooden utility poles are made","url":"https://assemblyline.org/make/utility-pole","stations":5,"upstream":1,"downstream":0,"depth":1,"dek":"Samuel Morse tried burying his 1844 telegraph line, gave up, and strung it on poles.","answer":"Wooden utility poles come from tall, straight trees, most often southern yellow pine in the United States. The logs are peeled, dried, trimmed and drilled for hardware, then loaded into a pressure cylinder where preservative is forced deep into the wood. The treated poles are stacked for shipping.","aka":["telephone pole","power pole","electricity pole"],"inputs":["timber"],"uses":[],"grounds":["timber"],"upstreamSlugs":["timber"],"downstreamSlugs":[],"steps":[{"name":"Fell the straight trees","process":"harvest","text":"Crews choose long straight trunks, and those are cut and hauled to the pole yard.","inputs":["timber"]},{"name":"Peel and trim","process":"machine","text":"Bark is shaved off and the pole is trimmed to a smooth taper.","inputs":[]},{"name":"Season the wood","process":"dry","text":"Poles are stacked to dry in air or in a heated chamber, because wet wood will not take up preservative.","inputs":[]},{"name":"Bore and brand","process":"machine","text":"Holes are drilled for crossarms and bolts before treatment, so preservative reaches the bare wood inside them. A brand burned into the butt records the species and class.","inputs":[]},{"name":"Force in preservative","process":"press","text":"Poles are sealed inside a long steel cylinder and the preservative is pushed in under pressure. It protects the wood from rot, fungi and insects. Creosote was traditional, and pentachlorophenol, copper naphthenate and borates are now common.","inputs":[]}],"facts":["The standard utility pole in the United States is about 35 feet tall and is buried about 6 feet in the ground.","In 1844, Congress granted Samuel Morse $30,000 to build a 40-mile telegraph line between Baltimore and Washington.","To carry that line, Morse advertised in a Washington newspaper for 700 straight chestnut posts with the bark on."],"where":[],"whereNote":null,"sources":[{"title":"Utility pole","url":"https://en.wikipedia.org/wiki/Utility_pole"},{"title":"Wood preservation","url":"https://en.wikipedia.org/wiki/Wood_preservation"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"vacuum-cleaner","name":"Vacuum cleaner","kind":"product","category":"machines","title":"How vacuum cleaners are made","url":"https://assemblyline.org/make/vacuum-cleaner","stations":11,"upstream":84,"downstream":0,"depth":11,"dek":"The first suction vacuum cleaners of 1901 were so large that one was pulled by horses and powered by a combustion engine.","answer":"Most parts of a vacuum cleaner arrive from subcontractors, but the big plastic pieces are usually injection molded on site. On the line, an upright model starts as a bare base. Workers drop in the beater bar and belt, latch on a steel plate, bolt on fan and motor, then snap the housing over them. Handle, hose and bag follow before inspection and boxing.","aka":["vacuum","hoover","stick vacuum"],"inputs":["plastic","rubber","steel","sheet-steel","electric-motor","copper-wire","paper","plastic-bag","cardboard-box"],"uses":[],"grounds":["natural-gas","natural-latex","sulfur","water","kaolin","limestone","crude-oil","air","iron-ore","dolomite","manganese-ore","zinc-ore","copper-ore","timber","coal","quartz","rock-salt","soybeans","rapeseed","clay","titanium-ore","corn","sugarcane","sugar-beet"],"upstreamSlugs":["plastic","rubber","steel","sheet-steel","electric-motor","copper-wire","paper","plastic-bag","cardboard-box","naphtha","natural-gas","ethylene","propylene","natural-latex","synthetic-rubber","carbon-black","sulfur","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc","epoxy","ball-bearing","copper","wood-pulp","water","kaolin","limestone","polyethylene","ink","cardboard","adhesive","crude-oil","hydrogen","benzene","styrene","air","iron-ore","coke","dolomite","silicon","propane","manganese-ore","sulfuric-acid","zinc-ore","phenol","acetone","chlorine","caustic-soda","steel-wire","copper-ore","timber","hydrogen-peroxide","vegetable-oil","phenolic-resin","titanium-dioxide","pigment","ethanol","acrylic","polyurethane","paraffin-wax","toluene","coal","quartz","charcoal","rock-salt","soybeans","rapeseed","hexane","clay","formaldehyde","titanium-ore","corn","sugarcane","yeast","ammonia","methanol","nitric-acid","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the plastic parts","process":"mold","text":"Pellets from a hopper melt in a heated vat and shoot into a two-part steel die under heat and pressure. Housings, wheels, bag fittings and clear dust canisters all come out this way, then wait in rolling bins. When enough are made, the die is swapped for the next part.","inputs":["plastic"]},{"name":"Make the rubberized parts","process":"mold","text":"The flexible hose that carries dust from fan to bag and the bumper around the housing are also produced in the factory.","inputs":["rubber"]},{"name":"Check incoming subassemblies","process":"inspect","text":"Parts built by subcontractors to the maker's specifications are inspected on arrival and stored in bins that roll to the line. Motors are bench tested before they go in.","inputs":[]},{"name":"Seat the beater bar","process":"assemble","text":"An upright begins with a base of metal or molded plastic. A steel bar fitted with brushes drops into notches at the front. From the bar, a rubber belt runs around a guide to the motor pulley.","inputs":["steel","rubber"]},{"name":"Latch the base plate","process":"assemble","text":"A steel plate with small rollers and openings for the brushes slots in under the belt and locks with a cam lever. Through those openings the brushes agitate the carpet and shake dirt loose.","inputs":["sheet-steel"]},{"name":"Fit axle and wheels","process":"assemble","text":"An axle slides through a tunnel across the rear of the base. A release lever on one end lets the operator drop or lock the handle, and wheels lock onto both ends.","inputs":[]},{"name":"Bolt on fan and motor","process":"assemble","text":"The fan bolts to the base and the motor assembly sits on top. Workers connect the motor to the fan, the headlight and the cord, and screw in a bulb at the front.","inputs":["electric-motor","copper-wire"]},{"name":"Snap on the housing","process":"assemble","text":"A plastic top with its bumper already wrapped on closes over motor and fan. A clear panel in it lets the headlight shine through.","inputs":[]},{"name":"Attach handle and bag","process":"assemble","text":"Plastic fittings for bag and handle go on at the rear, and the flexible hose links the base to the bag support. Wiring through the handle reaches a switch near the top, and the long cord is connected. A cloth outer bag and a disposable paper bag finish the machine, along with decals.","inputs":["paper","copper-wire"]},{"name":"Inspect the finished unit","process":"inspect","text":"Line workers and supervisors can reject anything along the way, and each machine gets a quality check at the end. Selected units are also switched on and run before packing.","inputs":[]},{"name":"Bag and box","process":"package","text":"The vacuum goes in a plastic bag and then a preprinted carton, with attachments and paperwork alongside. Cartons are sealed and stored for shipping.","inputs":["plastic-bag","cardboard-box"]}],"facts":["To convince friends that suction beat blowing, Hubert Cecil Booth knelt in a restaurant, sucked on a chair's covering and spat the dirt into a hankie.","Hubert Cecil Booth and David T. Kenney independently invented powered suction cleaners in 1901.","The 1868 Whirlwind used a belt-driven fan cranked by hand."],"where":[],"whereNote":null,"sources":[{"title":"Vacuum Cleaner, How Products Are Made","url":"https://encyclopedia.com/manufacturing/news-wires-white-papers-and-books/vacuum-cleaner"},{"title":"Vacuum cleaner","url":"https://en.wikipedia.org/wiki/Vacuum_cleaner"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"thermos","name":"Vacuum flask","kind":"product","category":"hardware","title":"How vacuum flasks are made","url":"https://assemblyline.org/make/thermos","stations":6,"upstream":44,"downstream":0,"depth":7,"dek":"A vacuum flask is two bottles, one inside the other, with the air pumped out of the gap between them.","answer":"A vacuum flask is two stainless steel vessels, one inside the other, welded at the neck. Sheet or tube is drawn or water-pressure formed into the two shells, then the air between them is pumped out, so heat can barely move by conduction or convection. Facing surfaces may be silvered to bounce back radiant heat.","aka":["Thermos","Dewar flask","insulated flask"],"inputs":["stainless-steel","silver","polyethylene"],"uses":[],"grounds":["silver-ore","lead-ore","zinc-ore","copper-ore","chromite","limestone","air","water","nickel-ore","sulfur","natural-gas","crude-oil","coal","rock-salt","trona","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["stainless-steel","silver","polyethylene","steel-scrap","chromium","nickel","oxygen","argon","silver-ore","lead-ore","zinc-ore","copper-ore","zinc","sulfuric-acid","lime","ethylene","propane","chromite","coke","soda-ash","limestone","air","water","aluminum","nickel-ore","sulfur","naphtha","natural-gas","crude-oil","coal","rock-salt","ammonia","carbon-dioxide","trona","petroleum-coke","alumina","hydrogen","corn","yeast","bauxite","caustic-soda","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Form two shells","process":"draw","text":"An inner liner and a slightly larger outer shell are shaped from stainless steel, by deep drawing sheet or by swelling tube with water pressure. Dewar's originals used glass and brass.","inputs":["stainless-steel"]},{"name":"Trim and neck the mouth","process":"machine","text":"Edges are trimmed and deburred, the mouth is necked in, and threads are formed for the lid. The two shells have to fit each other closely.","inputs":[]},{"name":"Silver the facing walls","process":"coat","text":"Surfaces facing the gap may be silvered, which reflects radiant heat back to where it came from.","inputs":["silver"]},{"name":"Weld them at the neck","process":"weld","text":"The inner vessel goes inside the outer one, and laser or TIG welding makes the airtight joint. That joint is the main solid path left for heat to travel through.","inputs":[]},{"name":"Pump out the gap","process":"separate","text":"Air is pumped from the space between the walls until it is a partial vacuum, and the opening is sealed. There is almost nothing left to carry heat across.","inputs":[]},{"name":"Fit the stopper or lid","process":"assemble","text":"A stopper or cap of polyethylene or cork goes on top. The neck and opening have no vacuum, so that is where heat gets out.","inputs":["polyethylene"]}],"facts":["James Dewar invented the vacuum flask in 1892 while studying the element palladium, and he never patented it.","Two German glassblowers, Reinhold Burger and Albert Aschenbrenner, made it a commercial product in 1904 and named it Thermos.","Large flasks sometimes need spacers to hold the inner vessel, but spacers also let heat leak through."],"where":[],"whereNote":null,"sources":[{"title":"Vacuum flask","url":"https://en.wikipedia.org/wiki/Thermos"},{"title":"How are Vacuum Flasks Made?","url":"https://www.renvergetech.com/how-are-vacuum-flasks-made"},{"title":"Manufacturing Process: How Metal Water Bottle Is Manufactured?","url":"https://www.everich.com/how-metal-water-bottle-is-manufactured/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"vanadium","name":"Vanadium","kind":"material","category":"metals","title":"How vanadium is made","url":"https://assemblyline.org/make/vanadium","stations":6,"upstream":25,"downstream":1,"depth":5,"dek":"Most of it is never mined for its own sake. About 90% is recovered from the slag left over from making steel.","answer":"Steel slag supplies most of the world's vanadium, with the metal first arriving in vanadium-bearing magnetite ore. Roasting the slag or ore with a sodium salt makes a compound that dissolves in hot water. Acid drops it out as a red cake, which is fused into oxide and reduced with aluminum to make ferrovanadium for tool steels.","aka":["ferrovanadium","vanadium pentoxide"],"inputs":["iron-ore","coal","soda-ash","water","sulfuric-acid","aluminum"],"uses":["wrench"],"grounds":["iron-ore","coal","water","rock-salt","limestone","trona","sulfur","air","crude-oil","natural-gas","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["iron-ore","coal","soda-ash","water","sulfuric-acid","aluminum","rock-salt","ammonia","limestone","carbon-dioxide","lime","trona","sulfur","air","crude-oil","petroleum-coke","alumina","natural-gas","corn","yeast","bauxite","caustic-soda","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["wrench"],"steps":[{"name":"Smelt the magnetite","process":"melt","text":"Titaniferous magnetite is reduced with coal to make iron. Most of the vanadium in the ore goes into the slag, which can hold up to 25% of the metal and is kept for the next step.","inputs":["iron-ore","coal"]},{"name":"Roast with soda ash","process":"bake","text":"Crushed slag or ore is mixed with a sodium salt and roasted at about 850 °C. The vanadium turns into sodium metavanadate, a compound that water can dissolve.","inputs":["soda-ash"]},{"name":"Leach in hot water","process":"wash","text":"Hot water washes the soluble metavanadate out of the roasted solids, leaving most of the waste behind as a residue.","inputs":["water"]},{"name":"Drop out the red cake","process":"react","text":"Sulfuric acid is added to the solution until the metal falls out as sodium hexavanadate, a solid known as red cake.","inputs":["sulfuric-acid"]},{"name":"Fuse into pentoxide","process":"melt","text":"Red cake is heated and fused into technical-grade vanadium pentoxide. Some of this oxide goes straight to sulfuric acid plants as catalyst, but most is headed for steel.","inputs":[]},{"name":"Reduce with aluminum","process":"melt","text":"Aluminum strips the oxygen from the pentoxide in the presence of iron, giving ferrovanadium. The most common grade holds 80% of the metal. Some plants use ferrosilicon and an electric arc furnace at 1,850 °C instead.","inputs":["aluminum"]}],"facts":["The first large-scale industrial use of vanadium was in the steel chassis of the Ford Model T.","The discoverer of vanadium, Andrés Manuel del Río, was talked out of his 1801 finding and told it was just chromium.","Less than 0.2 percent vanadium in structural steel is enough to improve its toughness, ductility and strength."],"where":[{"place":"China","share":"70% of world output"}],"whereNote":"2022 production of about 100,000 tons, as quoted on Wikipedia. China, South Africa and Russia together made more than 96%.","sources":[{"title":"Vanadium","url":"https://en.wikipedia.org/wiki/Vanadium"},{"title":"Ferrovanadium","url":"https://en.wikipedia.org/wiki/Ferrovanadium"},{"title":"Vanadium (Britannica)","url":"https://www.britannica.com/science/vanadium"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"vanilla-extract","name":"Vanilla extract","kind":"product","category":"food","title":"How vanilla extract is made","url":"https://assemblyline.org/make/vanilla-extract","stations":7,"upstream":13,"downstream":4,"depth":5,"dek":"Real vanilla extract is cured pods steeped in alcohol, and it contains hundreds of flavor compounds.","answer":"Vanilla extract is made from cured vanilla pods soaked and percolated in a mix of ethanol and water. In the United States, a product called pure vanilla extract must contain at least 35% alcohol and 100 grams of beans per litre. Pods get their flavor during a long curing process first, and the pollination is done by hand.","aka":["pure vanilla extract","vanilla essence","vanilla flavoring"],"inputs":["water","vanilla-pods","ethanol"],"uses":["ice-cream","cola","white-chocolate","caramel"],"grounds":["water","vanilla-pods","corn","sugarcane","natural-gas","sugar-beet","crude-oil"],"upstreamSlugs":["water","vanilla-pods","ethanol","corn","sugarcane","yeast","ethylene","molasses","naphtha","natural-gas","sugar-beet","crude-oil","hydrogen"],"downstreamSlugs":["ice-cream","cola","white-chocolate","caramel"],"steps":[{"name":"Pollinate each flower by hand","process":"grow","text":"Vanilla orchids rarely set fruit on their own outside their home range, so workers pollinate each flower by hand. The technique that made commercial farming possible was found in 1841 by Edmond Albius, a 12-year-old on the island of Reunion.","inputs":[]},{"name":"Pick the green pods","process":"harvest","text":"Each flower makes one pod, and pods are picked by hand when ripe. The pods smell of almost nothing at this stage, because the flavor compound is locked in a sugar-bound form.","inputs":[]},{"name":"Kill the living tissue","process":"cook","text":"Pods are scalded in hot water, frozen, scratched or heated in an oven, which stops the pod from growing and breaks open its cells. Enzymes then start turning glucovanillin into vanillin. Hot water treatment can be as short as 3 minutes at 63 to 65 °C.","inputs":["water"]},{"name":"Sweat them in blankets","process":"dry","text":"Warm pods are wrapped in cloth and left to sweat so the enzymes keep working and the beans turn dark brown. This sweating stage is the first part of the cure.","inputs":[]},{"name":"Dry slowly and condition","process":"dry","text":"Pods are dried over weeks, then stored in boxes so the aroma rounds out. The cure always has the same four parts, which are killing, sweating, slow drying and conditioning.","inputs":[]},{"name":"Steep in alcohol","process":"mix","text":"Chopped pods are macerated and percolated in a solution of ethanol and water. The alcohol dissolves the vanillin and several hundred other flavor compounds.","inputs":["vanilla-pods","ethanol","water"]},{"name":"Age, filter and bottle","process":"fill","text":"The extract rests, is filtered, and is bottled. Double and triple strength extracts for factories use many times more beans per litre.","inputs":[]}],"facts":["An estimated 95% of products sold as vanilla use vanillin made from lignin, not from vanilla pods.","Bourbon vanilla has nothing to do with whiskey. It is named for the Bourbon Islands, such as Reunion, ruled by France's Bourbon kings.","Mexico was the chief producer of vanilla until the middle of the 19th century."],"where":[],"whereNote":null,"sources":[{"title":"Vanilla extract","url":"https://en.wikipedia.org/wiki/Vanilla_extract"},{"title":"Vanilla","url":"https://en.wikipedia.org/wiki/Vanilla"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"vanilla-pods","name":"Vanilla pods","kind":"raw","category":"farm","title":"How vanilla is grown and harvested","url":"https://assemblyline.org/make/vanilla-pods","stations":3,"upstream":0,"downstream":12,"depth":0,"dek":"Every commercial vanilla flower is pollinated by hand, and the discovery was made by a 12-year-old in 1841.","answer":"Vanilla is an orchid vine grown on a tree or frame in hot, humid places near the equator. Its flowers open for a single day, so workers pollinate each one by hand within 12 hours. The green pods ripen at different times, and pickers return daily to harvest them one by one.","aka":["vanilla beans","vanilla orchid","vanilla farming","vanilla planifolia","vanilla harvest"],"inputs":[],"uses":["perfume","vanilla-extract"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["perfume","vanilla-extract","shampoo","deodorant","air-freshener","dish-soap","hairspray","foundation-makeup","ice-cream","cola","white-chocolate","caramel"],"steps":[{"name":"Train the vine","process":"grow","text":"Vanilla climbs a tree or frame, such as bamboo or coconut, in a hot, humid climate with about 80% humidity. It does best within 10 to 20 degrees of the equator and in loose soil rich in organic matter.","inputs":[]},{"name":"Pollinate each flower by hand","process":"grow","text":"Without pollination a blossom wilts and falls, and wild vanilla has only a 1% chance of it. A worker lifts a flap in the flower with a wood splinter and presses the anther against the stigma. It has to be done within 12 hours of the flower opening.","inputs":[],"spec":"within 12 hours of opening"},{"name":"Pick pods one by one","process":"harvest","text":"Each pod ripens on its own schedule, so harvest happens daily. Dark green pods are left, and pale yellow at the tip is a poor sign of maturity. Flavor compounds build for about 40 weeks after pollination.","inputs":[]}],"facts":["In 1841 Edmond Albius, a 12-year-old enslaved boy on the island of Réunion, found how to pollinate the flower by hand.","By weight, vanilla is the second most expensive spice, after saffron.","A pod longer than 15 cm is classed first-quality."],"where":[],"whereNote":null,"sources":[{"title":"Vanilla","url":"https://en.wikipedia.org/wiki/Vanilla"},{"title":"Vanilla planifolia","url":"https://en.wikipedia.org/wiki/Vanilla_planifolia"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"vegetable-oil","name":"Vegetable oil","kind":"material","category":"food","title":"How vegetable oil is made","url":"https://assemblyline.org/make/vegetable-oil","stations":7,"upstream":8,"downstream":161,"depth":3,"dek":"Most vegetable oil is washed out of crushed beans with hexane, which is then boiled off.","answer":"Seeds are cleaned, cracked and flaked, then pressed or soaked in hexane, a petroleum solvent, to pull out the oil. Heat evaporates the solvent. The crude oil is then refined: gums are removed, free fatty acids neutralized, color bleached out, and smells stripped by steam under vacuum.","aka":["cooking oil","salad oil","soybean oil","canola oil","seed oil"],"inputs":["soybeans","rapeseed","hexane","water","clay"],"uses":["soap","shampoo","deodorant","sunscreen","mascara","detergent","ink","glycerin","cast-iron-pan","margarine","mayonnaise","peanut-butter","tortilla","donut","sandwich-cookie","potato-chips","french-fries","canned-tuna","chicken-nuggets","baby-formula","oat-milk","crackers","fish-sticks","biodiesel","wooden-spoon","pencil-eraser","modeling-clay","cake-mix","foundation-makeup"],"grounds":["soybeans","rapeseed","water","clay","crude-oil","natural-gas"],"upstreamSlugs":["soybeans","rapeseed","hexane","water","clay","crude-oil","hydrogen","natural-gas"],"downstreamSlugs":["soap","shampoo","deodorant","sunscreen","mascara","detergent","ink","glycerin","cast-iron-pan","margarine","mayonnaise","peanut-butter","tortilla","donut","sandwich-cookie","potato-chips","french-fries","canned-tuna","chicken-nuggets","baby-formula","oat-milk","crackers","fish-sticks","biodiesel","wooden-spoon","pencil-eraser","modeling-clay","cake-mix","foundation-makeup","syringe","plastic-bag","credit-card","tin-can","aluminum-can","windshield","skateboard","golf-ball","baseball","basketball","soccer-ball","rubiks-cube","ballpoint-pen","paper-cup","pizza-box","wallpaper","laminate-floor","marker-pen","highlighter","ski","snowboard","frisbee","board-game","jigsaw-puzzle","trading-cards","globe","candy-coated-chocolate","floor-tile","vinyl-floor","underwear","flip-flops","flag","vinyl-record","compact-disc","inkjet-printer","cardboard-box","newspaper","book","sticky-notes","playing-cards","banknote","t-shirt","umbrella","toothpaste","chewing-gum","snow-globe","cough-syrup","gelatin-capsule","diesel","vacuum-cleaner","electric-kettle","cotton-candy","pillow","paint","condensed-milk","coconut-milk","canned-meat","canned-soup","cola","sparkling-water","beer","hard-cider","soda","root-beer","energy-drink","tonic-water","light-beer","non-alcoholic-beer","insect-repellent","car","electric-car","nitrile-glove","washing-machine","paperclip","corn-flakes","popcorn","crayon","fireworks","candle","salsa","zip-bag","blender","dishwasher","cotton-swab","mouthwash","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","facial-tissue","envelope","locomotive","refrigerator","microwave-oven","pencil","scissors","mirror","airplane","container-ship","shipping-container","bicycle","motorcycle","wooden-chair","water-bottle","ceiling-fan","water-heater","tennis-racket","golf-club","fishing-rod","bowling-ball","billiard-ball","dartboard","dice","action-figure","fashion-doll","toy-car","coil-spring","hammer","fire-extinguisher","gas-cylinder","neon-sign","suspension-bridge-cable","aluminum-window-frame","brake-pad","subway-train","leather-belt","eyeglass-frame","toffee","padlock"],"steps":[{"name":"Clean and crack the seeds","process":"crush","text":"Soybeans or rapeseed are cleaned of stalks and dirt, then cracked and rolled into thin flakes. Flaking breaks open the oil cells and gives the extractor far more surface to work on.","inputs":["soybeans","rapeseed"]},{"name":"Press out the first oil","process":"press","text":"An expeller, which is a big screw press, squeezes part of the oil out mechanically. Oil from this step is the usual route for traditional oils, and it is preferred by many natural-food buyers.","inputs":[]},{"name":"Wash with solvent","process":"separate","text":"Most newer industrial oils such as soybean and corn are extracted with hexane. Flakes move through a bath of solvent that dissolves the oil, which gives higher yields faster and more cheaply than pressing.","inputs":["hexane"]},{"name":"Boil off the hexane","process":"refine","text":"The oil and solvent mix is heated to around 149 °C so the solvent evaporates. It is condensed and reused, and the defatted flake left behind becomes high-protein animal feed.","inputs":[],"spec":"about 149 °C"},{"name":"Degum and neutralize","process":"refine","text":"Crude oil is washed with water and mild alkali to remove gums and free fatty acids. These impurities would smoke when frying and shorten the shelf life.","inputs":["water"]},{"name":"Bleach out the color","process":"refine","text":"A clay-like bleaching earth adsorbs the pigments, and filtering leaves the pale gold color shoppers expect.","inputs":["clay"]},{"name":"Steam out the smell","process":"refine","text":"The oil is heated under vacuum to roughly 232 °C while steam is bubbled through from the bottom. The steam carries off volatile compounds that would taste or smell like beans. Deodorization is a core step in producing refined oil.","inputs":[],"spec":"about 232 °C under vacuum"}],"facts":["Procter and Gamble marketed Crisco, a cottonseed oil product partly hydrogenated until solid, as early as 1911.","Supercritical carbon dioxide can replace hexane as a non-toxic solvent."],"where":[],"whereNote":null,"sources":[{"title":"Vegetable oil","url":"https://en.wikipedia.org/wiki/Vegetable_oil"},{"title":"Rapeseed oil","url":"https://en.wikipedia.org/wiki/Rapeseed_oil"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"game-console","name":"Video game console","kind":"product","category":"electronics","title":"How video game consoles are made","url":"https://assemblyline.org/make/game-console","stations":7,"upstream":108,"downstream":0,"depth":10,"dek":"A Sony line in Japan builds a PS4 in 30 seconds, and 26 of its 32 robots just wrangle floppy cables.","answer":"On a line 31.4 meters long at Sony's Kisarazu site in Japan, 32 robots build a PlayStation 4 in 30 seconds. People load finished motherboards at one end and pack consoles at the other. In between, robots plug in soft cables and tighten screws, and each console is inspected and gets its main cover.","aka":["games console","home console","gaming system"],"inputs":["printed-circuit-board","microchip","memory-chip","solid-state-drive","solder","abs-plastic","polycarbonate","copper-wire","copper","aluminum","electric-motor","screw","cardboard-box"],"uses":[],"grounds":["air","copper-ore","water","crude-oil","coal","silica-sand","limestone","quartz","tin-ore","gold-ore","lead-ore","silver-ore","zinc-ore","natural-gas","iron-ore","sulfur","rock-salt","bauxite","trona","titanium-ore","dolomite","manganese-ore","timber","soybeans","rapeseed","clay","corn","sugarcane","sugar-beet"],"upstreamSlugs":["printed-circuit-board","microchip","memory-chip","solid-state-drive","solder","abs-plastic","polycarbonate","copper-wire","copper","aluminum","electric-motor","screw","cardboard-box","fiberglass","epoxy","photoresist","silicon-wafer","oxygen","tin","gold","nitrogen","lead","silver","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","phenol","acetone","caustic-soda","chlorine","copper-ore","water","sulfuric-acid","crude-oil","coal","petroleum-coke","alumina","sheet-steel","ball-bearing","steel","steel-wire","zinc","cardboard","ink","adhesive","silica-sand","limestone","soda-ash","phenolic-resin","polysilicon","quartz","argon","tin-ore","coke","gold-ore","lime","lead-ore","silver-ore","zinc-ore","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","carbon-black","sulfur","rock-salt","bauxite","pig-iron","magnesium","steel-scrap","manganese","wood-pulp","vegetable-oil","ethanol","polyethylene","acrylic","polyurethane","paraffin-wax","carbon-dioxide","trona","formaldehyde","silicon","hydrochloric-acid","trichlorosilane","titanium-ore","dolomite","propane","manganese-ore","timber","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","corn","sugarcane","yeast","methanol","nitric-acid","charcoal","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Build the motherboard","process":"assemble","text":"Before final assembly, the main processor, an APU that combines processing and graphics on one chip, goes on a circuit board ringed by memory chips, with storage and power parts soldered alongside.","inputs":["printed-circuit-board","microchip","memory-chip","solid-state-drive","solder"]},{"name":"Mold the shell","process":"mold","text":"Plastic is molded into the top and bottom of the case. On a PlayStation the main unit cover carries the triangle, circle, cross and square.","inputs":["abs-plastic","polycarbonate"]},{"name":"Feed the boards in","process":"assemble","text":"At Kisarazu, two workers put motherboards on the start of the line, and robotic arms carry them onward. The area beyond was off-limits even to Sony employees.","inputs":[]},{"name":"Plug in the soft parts","process":"assemble","text":"Of the 32 robots, 26 deal with floppy items such as antenna cables and tape-like parts. One arm holds a cable while another grips its tip, twists it to the right angle and slides it into the connector with controlled force. Parts too awkward to grip get sucked up instead.","inputs":["copper-wire"]},{"name":"Fit cooling and tighten screws","process":"assemble","text":"Slender arms connect wires and tighten screws, with one robot sliding sideways to do two jobs. A metal heat sink and heat pipe sit on the hot chip, and a fan draws air across them.","inputs":["copper","aluminum","electric-motor","screw"],"spec":"31.4 m by 6 m"},{"name":"Inspect and cover","process":"inspect","text":"Each finished console is examined. The main unit cover goes on as the last production step, and a crane lifts each console that passed onto a lane headed for packing.","inputs":[]},{"name":"Pack by hand","process":"package","text":"Two more workers pack the consoles. Sony kept people here and at the start of the line from 2019, having judged that mix the best return on its investment. Boxes carry handling instructions in several languages.","inputs":["cardboard-box"]}],"facts":["The Nintendo Switch popularized the hybrid console, with detachable controllers that dock into a screen.","Makers often sell consoles at low prices, sometimes at a loss, and earn their profit from licensing fees on each game.","Sony's PS4 line at Kisarazu began with more than 80 robots, and reworking every process cut that to 32."],"where":[],"whereNote":null,"sources":[{"title":"Video game console","url":"https://en.wikipedia.org/wiki/Video_game_console"},{"title":"Graphics card","url":"https://en.wikipedia.org/wiki/Graphics_card"},{"title":"The PlayStation's inner sanctum (Nikkei)","url":"https://vdata.nikkei.com/en/newsgraphics/sony-playstation"},{"title":"Sony factory assembles PS4 in 30 seconds, only four humans involved in process","url":"https://www.techspot.com/news/85881-sony-factory-assembles-ps4-30-seconds-only-four.html"},{"title":"Robots With A Delicate Touch Assemble PlayStation 4","url":"https://hackaday.com/2020/08/18/robots-with-a-delicate-touch-assemble-playstation-4"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"vinegar","name":"Vinegar","kind":"product","category":"food","title":"How vinegar is made","url":"https://assemblyline.org/make/vinegar","stations":6,"upstream":15,"downstream":6,"depth":5,"dek":"Vinegar is wine's second life. Bacteria turn alcohol into acid in tanks fed with air.","answer":"Vinegar is made by double fermentation. Yeast first turns sugar in grape juice, malt or grain into alcohol, then acetic acid bacteria with plenty of air turn the alcohol into acetic acid. Slow methods take months, while the submerged tank method used for cheap vinegar needs only 1 to 3 days.","aka":["white vinegar","distilled vinegar","wine vinegar","malt vinegar","cider vinegar"],"inputs":["grapes","ethanol","malted-barley","yeast","water"],"uses":["mayonnaise","ketchup","mustard","hot-sauce","salsa","pickles"],"grounds":["grapes","water","corn","sugarcane","barley","natural-gas","sugar-beet","crude-oil"],"upstreamSlugs":["grapes","ethanol","malted-barley","yeast","water","corn","sugarcane","ethylene","barley","molasses","naphtha","natural-gas","sugar-beet","crude-oil","hydrogen"],"downstreamSlugs":["mayonnaise","ketchup","mustard","hot-sauce","salsa","pickles"],"steps":[{"name":"Pick a sugary liquid","process":"mix","text":"Makers start from fruit juice, grape must, malted grain or a plain solution of grain alcohol. Balsamic vinegar starts from grape product, malt vinegar starts from beer, and spirit vinegar begins with distilled ethanol.","inputs":["grapes","ethanol","malted-barley"]},{"name":"Ferment sugar to alcohol","process":"ferment","text":"Yeast eats the sugars in the liquid and gives off alcohol. This first fermentation is the same one that makes wine or beer.","inputs":["yeast"]},{"name":"Add the acid bacteria","process":"grow","text":"A starter, sometimes called mother of vinegar, brings in acetic acid bacteria. Traditional makers let a slime-like mat of the bacteria float on the surface of barrels.","inputs":[]},{"name":"Bubble in air","process":"ferment","text":"The bacteria need oxygen to turn ethanol into acetic acid. In a submerged fermenter, air is pumped through the liquid constantly, and the fast route finishes in 1 to 3 days. Slow barrel methods take a few months up to a year.","inputs":[],"spec":"1 to 3 days in a fast tank"},{"name":"Filter and standardize","process":"separate","text":"The liquid is filtered to remove bacteria and solids, then diluted with water to a set strength. Vinegar typically contains from 4% to 18% acetic acid by volume.","inputs":["water"]},{"name":"Pasteurize and bottle","process":"pasteurize","text":"A short heat treatment stops any leftover bacteria from working. Vinegar is then bottled, and some kinds are aged in wood first.","inputs":[]}],"facts":["The first documented vinegar making was by the ancient Babylonians around 3000 BCE, from dates, figs and beer.","Karl Sebastian Schuzenbach built the first large-scale industrial vinegar process in 1823, trickling alcohol over beechwood shavings."],"where":[],"whereNote":null,"sources":[{"title":"Vinegar","url":"https://en.wikipedia.org/wiki/Vinegar"},{"title":"Baker's yeast","url":"https://en.wikipedia.org/wiki/Baker%27s_yeast"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"vinyl-floor","name":"Vinyl flooring","kind":"product","category":"plastics","title":"How vinyl flooring is made","url":"https://assemblyline.org/make/vinyl-floor","stations":8,"upstream":48,"downstream":0,"depth":8,"dek":"The wood grain on a vinyl plank is a printed film, and the texture is pressed in to line up with the picture.","answer":"Luxury vinyl tile starts as PVC compounded with plasticizer, stabilizers and mineral filler. Heated calenders turn that into a core, often built around a fiberglass mat. A printed decor film and a clear PVC wear layer are laminated on under heat and pressure, rollers emboss the texture, a UV-cured coating sets the surface, and the cooled sheet is cut.","aka":["vinyl tile","vinyl composition tile","LVT"],"inputs":["pvc","plasticizer","limestone","fiberglass","ink"],"uses":[],"grounds":["limestone","water","air","silica-sand","natural-gas","rock-salt","iron-ore","sulfur","crude-oil","trona","soybeans","rapeseed","clay","titanium-ore","corn","sugarcane","coal","sugar-beet"],"upstreamSlugs":["pvc","plasticizer","limestone","fiberglass","ink","ethylene","chlorine","water","pigment","naphtha","air","propylene","silica-sand","soda-ash","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","ethanol","natural-gas","rock-salt","sulfuric-acid","iron-ore","sulfur","crude-oil","hydrogen","ammonia","carbon-dioxide","lime","trona","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","titanium-ore","coke","oxygen","corn","sugarcane","yeast","benzene","methanol","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Compound the PVC","process":"mix","text":"Raw PVC is kneaded with plasticizer, stabilizers and fillers such as limestone powder, then degassed to remove trapped air. Plasticizer sets how firm the tile feels, and stabilizers protect it from the heat of the line.","inputs":["pvc","plasticizer","limestone"]},{"name":"Calender the core","process":"roll","text":"Softened compound runs between heated rollers that set its thickness. In one line described by the machinery maker BUSS, the first calender coats a fiberglass mat and the second coats its other side.","inputs":["fiberglass"]},{"name":"Bond the print film","process":"laminate","text":"A printed film showing wood or stone is fused to the base under heat and pressure.","inputs":["ink"]},{"name":"Laminate the wear layer","process":"laminate","text":"A separate, ready-made clear PVC film feeds on through hot rollers and fuses to the print. This film's thickness is the mil rating on the box.","inputs":["pvc"],"spec":"12 mil or 20 mil is typical"},{"name":"Emboss the texture","process":"press","text":"A textured roller or plate presses into the clear layer. On embossed-in-register lines, a mark or sensor in the print keeps knots and grain lined up with the dips underfoot.","inputs":[]},{"name":"Cure the top coat","process":"coat","text":"A thin liquid urethane or acrylic coating is rolled on and hit with ultraviolet light. It sets within seconds, and every part of the sheet gets the same exposure.","inputs":[]},{"name":"Temper and cool","process":"chill","text":"The layered sheet passes through a tempering stretch and is then cooled before it reaches the cutters.","inputs":[]},{"name":"Cut to measure","process":"cut","text":"Machines cut the sheet into planks or tiles. Line checks cover wear layer thickness, gloss, adhesion and any visible flaws.","inputs":[]}],"facts":["A 20-mil wear layer on a vinyl plank is only roughly 0.5 mm of clear PVC.","Philadelphia architect Frank Furness won an 1894 patent on rubber floor tiles, a forerunner of resilient flooring."],"where":[],"whereNote":null,"sources":[{"title":"Vinyl composition tile","url":"https://en.wikipedia.org/wiki/Vinyl_composition_tile"},{"title":"How Vinyl Sheet Flooring Wear Layers are Made, Coverings","url":"https://coveringscanada.ca/how-vinyl-flooring-wear-layers-are-made/"},{"title":"Compounding systems for luxury vinyl tiles, BUSS","url":"https://busslist.com/application/luxury-vinyl-tiles-lvt/"},{"title":"What Is LVT Flooring Made Of?, Tile Mountain","url":"https://www.tilemountain.co.uk/blog/what-is-lvt-flooring-made-of/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"vinyl-record","name":"Vinyl record","kind":"product","category":"electronics","title":"How vinyl records are made","url":"https://assemblyline.org/make/vinyl-record","stations":9,"upstream":63,"downstream":0,"depth":8,"dek":"Every vinyl record is squeezed between two nickel plates under about 150 tons of pressure.","answer":"A vinyl record starts as an aluminum disc coated in nitrocellulose lacquer, into which a lathe engraves the sound as a spiral groove. The lacquer is sprayed with silver and electroplated with nickel to make metal stampers. In a hydraulic press, a heated biscuit of PVC is squeezed between two stampers with a label on each side.","aka":["LP","gramophone record","phonograph record","45"],"inputs":["aluminum","lacquer","silver","nickel","paper","ink","pvc","carbon-black"],"uses":[],"grounds":["crude-oil","coal","silver-ore","lead-ore","zinc-ore","copper-ore","nickel-ore","water","kaolin","limestone","air","bauxite","corn","sugarcane","sulfur","timber","soybeans","rapeseed","clay","titanium-ore","iron-ore","natural-gas","rock-salt","sugar-beet"],"upstreamSlugs":["aluminum","lacquer","silver","nickel","paper","ink","pvc","carbon-black","crude-oil","coal","petroleum-coke","alumina","ethanol","acrylic","silver-ore","lead-ore","zinc-ore","copper-ore","zinc","sulfuric-acid","lime","nickel-ore","wood-pulp","water","kaolin","limestone","vegetable-oil","phenolic-resin","titanium-dioxide","pigment","ethylene","chlorine","plasticizer","air","bauxite","caustic-soda","corn","sugarcane","yeast","propylene","ammonia","methanol","sulfur","timber","oxygen","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","titanium-ore","coke","iron-ore","naphtha","natural-gas","rock-salt","molasses","hydrogen","benzene","sugar-beet","toluene"],"downstreamSlugs":[],"steps":[{"name":"Coat the blank disc","process":"coat","text":"An aluminum core is sanded smooth and coated in nitrocellulose lacquer on a conveyor. Any flaw in the coat ruins the result, so the failure rate at inspection is very high.","inputs":["aluminum","lacquer"]},{"name":"Cut the groove","process":"machine","text":"A cutting lathe drives a hard stylus into the coated disc, engraving a spiral groove whose wiggles are the sound wave. The lacquer can be played only a few times before it degrades.","inputs":[]},{"name":"Silver the lacquer","process":"deposit","text":"The disc is washed and sprayed with tin chloride and liquid silver, which gives it a conductive skin. Silver that does not stick is washed away.","inputs":["silver"]},{"name":"Plate it in nickel","process":"coat","text":"The disc goes into a tank of dissolved nickel, and electric charge builds nickel up on the silver surface. The metal layer is then peeled off as a negative of the groove.","inputs":["nickel"]},{"name":"Finish the stampers","process":"coat","text":"Further plating can make more copies, ending in working stampers, one for each side of the record. An optical punch centers the hole, and excess metal is trimmed off.","inputs":["nickel"]},{"name":"Punch the labels","process":"cut","text":"Labels are printed in square stacks, then punched in the center and trimmed into circles. They have to be ready first, because they fuse to the record in the press.","inputs":["paper","ink"]},{"name":"Form the biscuit","process":"melt","text":"PVC pellets, with carbon for black records, are heated to a molten state and formed into a soft lump called a biscuit or puck.","inputs":["pvc","carbon-black"]},{"name":"Press the record","process":"mold","text":"With a label on each side, the biscuit is centered between two nickel stampers in a hydraulic press. The press closes under about 150 tons of pressure, and the vinyl fills every groove within seconds.","inputs":[]},{"name":"Cool and trim","process":"chill","text":"The record is cooled with water or air, and the excess vinyl around the edge, called flash, is trimmed off and can be reused. Records are checked, sleeved and boxed.","inputs":[]}],"facts":["Recycled vinyl pellets come from trimmed waste and unsold records, and they can bring more surface noise than virgin vinyl.","Vinyl records replaced the old shellac 78s, and by 1958 vinyl was standard."],"where":[],"whereNote":null,"sources":[{"title":"Phonograph record","url":"https://en.wikipedia.org/wiki/Phonograph_record"},{"title":"Record press","url":"https://en.wikipedia.org/wiki/Record_press"},{"title":"How vinyl records are made (Your Sound Matters)","url":"https://www.yoursoundmatters.com/vinyl-records-made/"},{"title":"How vinyl records are pressed and perfected (Hypebot)","url":"https://www.hypebot.com/how-vinyl-records-are-pressed-and-perfected/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"violin","name":"Violin","kind":"product","category":"play","title":"How violins are made","url":"https://assemblyline.org/make/violin","stations":8,"upstream":47,"downstream":0,"depth":8,"dek":"A violin's top and back are carved to a varying thickness, and that profile shapes its sound.","answer":"A violin is carved and bent from tonewoods: a spruce top, maple back and ribs, and an ebony fingerboard. The pieces are glued into a hollow box with a neck and scroll, edged with inlaid purfling, varnished, and fitted with a bridge, a sound post inside and four strings. Its tone depends on how the wood is carved.","aka":["fiddle"],"inputs":["timber","adhesive","steel-wire","nylon"],"uses":[],"grounds":["timber","water","crude-oil","air","natural-gas","sulfur","rock-salt","iron-ore","limestone","dolomite","manganese-ore","coal","quartz"],"upstreamSlugs":["timber","adhesive","steel-wire","nylon","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","steel","benzene","nitric-acid","ammonia","ethylene","propylene","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","crude-oil","hydrogen","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","naphtha","toluene","air","natural-gas","sulfur","rock-salt","iron-ore","coke","limestone","dolomite","silicon","propane","manganese-ore","coal","quartz","charcoal"],"downstreamSlugs":[],"steps":[{"name":"Carve the top and back","process":"machine","text":"A spruce top and a maple back are carved from the outside, then hollowed from inside to a graduated thickness, thicker in some places and thinner in others. That thickness profile has a big influence on the sound.","inputs":["timber"]},{"name":"Bend the ribs","process":"mold","text":"Thin maple strips are heated and bent round a mold into the violin's waist and curves. End blocks hold them in place.","inputs":["timber"]},{"name":"Glue up the box","process":"assemble","text":"Top and back are glued to the ribs. Weaker, diluted glue is used on the top, so repairs can open the case later without damage.","inputs":["adhesive"]},{"name":"Inlay the purfling","process":"machine","text":"A groove is cut around the edge of the top and a thin strip is set in. Real purfling gives some protection against cracks and lets the top flex independently of the ribs.","inputs":[]},{"name":"Carve the neck and scroll","process":"machine","text":"A maple block becomes the neck, pegbox and scroll in one piece. It is fitted to the body and topped with an ebony fingerboard, chosen for hardness and wear resistance.","inputs":["timber"]},{"name":"Varnish the wood","process":"coat","text":"Coats of varnish seal the wood and color it. Both varnish and wood affect the sound, and the instrument is said to improve with age.","inputs":[]},{"name":"Set the bridge and sound post","process":"assemble","text":"A thin spruce sound post is stood upright between top and back, near the treble foot of the bridge. The bridge is cut to hold the four strings in an arc so a bow can sound each one.","inputs":[]},{"name":"Add strings and tune","process":"assemble","text":"Strings may be gut, synthetic or steel, anchored at the tailpiece and tuned by pegs. Gut strings are made of sheep gut, not cat.","inputs":["steel-wire","nylon"]}],"facts":["Catgut strings do not come from cats. They were made of stretched, dried and twisted sheep gut.","Painted-on fake purfling is usually a sign of a cheap violin.","Bow hair is traditionally horsehair, and solid rosin rubbed onto it makes the string grip and vibrate."],"where":[],"whereNote":null,"sources":[{"title":"Violin","url":"https://en.wikipedia.org/wiki/Violin"},{"title":"Luthier","url":"https://en.wikipedia.org/wiki/Luthier"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"vitamin-c","name":"Vitamin C tablet","kind":"product","category":"body-health","title":"How vitamin C tablets are made","url":"https://assemblyline.org/make/vitamin-c","stations":7,"upstream":22,"downstream":18,"depth":7,"dek":"Industrial vitamin C is built from plain glucose, with bacteria doing one of the hardest steps.","answer":"Industrial vitamin C starts with glucose from corn starch. Hydrogen turns it into sorbitol, bacteria convert the sorbitol into a sugar called sorbose, and further chemical steps turn that into ascorbic acid. The crystals are purified, dried, blended with binders and pressed into tablets.","aka":["ascorbic acid","vitamin C supplement","ascorbate"],"inputs":["corn-starch","water","hydrogen","air","sugar","plastic-bottle"],"uses":["flour"],"grounds":["water","air","corn","natural-gas","sugarcane","sugar-beet","limestone","crude-oil"],"upstreamSlugs":["corn-starch","water","hydrogen","air","sugar","plastic-bottle","corn","natural-gas","sugarcane","sugar-beet","lime","pet-plastic","limestone","p-xylene","ethylene","ethylene-glycol","naphtha","oxygen","carbon-dioxide","crude-oil","yeast","molasses"],"downstreamSlugs":["flour","bread","instant-noodles","tortilla","croissant","donut","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","fish-sticks","modeling-clay","licorice","cake-mix"],"steps":[{"name":"Break the starch into glucose","process":"react","text":"Corn starch is treated with enzymes until it falls apart into glucose, a simple sugar.","inputs":["corn-starch","water"]},{"name":"Hydrogenate the glucose","process":"react","text":"In a pressure vessel, hydrogen over a nickel catalyst turns glucose into sorbitol, a sugar alcohol.","inputs":["hydrogen"]},{"name":"Ferment the sorbitol","process":"ferment","text":"Acetobacter bacteria oxidize the sorbitol into sorbose. The microbes do this step because they can get the shape of the molecule right, which chemistry alone struggles to do.","inputs":["air"]},{"name":"Convert to ascorbic acid","process":"react","text":"Chemical steps then oxidize sorbose and close it into a ring, giving ascorbic acid. The classic route takes five steps, and newer routes shorten it.","inputs":[]},{"name":"Crystallize and dry","process":"separate","text":"The acid is crystallized out, washed and dried into a pure white powder.","inputs":[]},{"name":"Blend and press","process":"press","text":"Powder is blended with a binder and a sweetener, then pressed into tablets by a rotary press.","inputs":["sugar"]},{"name":"Count and bottle","process":"package","text":"Tablets are counted by machine into bottles with a desiccant and sealed.","inputs":["plastic-bottle"]}],"facts":["The Reichstein process, devised in 1933, combines chemistry and microbial steps to make ascorbic acid from glucose.","Reichstein's process was patented and sold to Hoffmann-La Roche in 1934.","In 1988, Genencor International and Eastman Chemical announced a shorter biotech route that cut the five steps to two."],"where":[],"whereNote":null,"sources":[{"title":"Vitamin C","url":"https://en.wikipedia.org/wiki/Vitamin_C"},{"title":"Reichstein process","url":"https://en.wikipedia.org/wiki/Reichstein_process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"vodka","name":"Vodka","kind":"product","category":"drink","title":"How vodka is made","url":"https://assemblyline.org/make/vodka","stations":7,"upstream":27,"downstream":0,"depth":6,"dek":"Vodka is distilled until almost nothing but alcohol is left, then watered down to bottling strength.","answer":"Vodka is ethanol and water. Grain or potatoes are cooked, fermented, and distilled over and over in column stills until almost pure alcohol is left. That neutral spirit is filtered, diluted with water to bottling strength and bottled. Unlike whiskey, it is not aged in wood, and it has no required flavor.","aka":["wódka","neutral spirit"],"inputs":["wheat","corn","potatoes","water","rye","yeast","charcoal","glass-bottle"],"uses":[],"grounds":["wheat","corn","potatoes","water","rye","timber","silica-sand","limestone","sugarcane","sugar-beet","rock-salt","trona","natural-gas","air","crude-oil"],"upstreamSlugs":["wheat","corn","potatoes","water","rye","yeast","charcoal","glass-bottle","molasses","timber","silica-sand","soda-ash","limestone","polyethylene","sugarcane","sugar-beet","rock-salt","ammonia","carbon-dioxide","lime","trona","ethylene","natural-gas","air","naphtha","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Cook the starch","process":"cook","text":"Grain such as wheat, rye or corn, or potatoes, is cooked in water so the starch breaks down. Enzymes then convert it into fermentable sugar.","inputs":["wheat","corn","potatoes","water","rye"]},{"name":"Ferment the mash","process":"ferment","text":"Yeast eats the sugars and produces a weak, beer-like alcoholic liquid. A few producers start from a plain solution of sugar and yeast instead.","inputs":["yeast"]},{"name":"Strip off the alcohol","process":"refine","text":"The liquid is boiled in a still and the vapors are condensed to a stronger liquid. Repeating the process with column stills makes a spirit that is nearly pure alcohol.","inputs":[]},{"name":"Rectify to neutral","process":"refine","text":"Further stages remove flavor-bearing compounds until the spirit has almost no taste or smell of its own. Many bottlers buy this neutral spirit in bulk from a few large distilleries.","inputs":[],"spec":"about 95% pure grain alcohol"},{"name":"Filter through carbon","process":"separate","text":"Some producers pass the spirit through charcoal to polish it. Filtering is optional in the US.","inputs":["charcoal"]},{"name":"Cut with water","process":"mix","text":"Water is blended in to bring the alcohol content down from nearly pure to bottling strength. Standard vodkas are bottled at 40% alcohol by volume.","inputs":["water"],"spec":"40% ABV"},{"name":"Bottle it clear","process":"fill","text":"The vodka is bottled, usually straight away. By US rules it cannot be aged in wood.","inputs":["glass-bottle"]}],"facts":["The English word vodka comes from Russian and means little water.","The European Union sets a minimum alcohol content of 37.5% for vodka.","A blind test run by the NPR program Planet Money found negligible differences in taste between brands of vodka.","In 1782 J. A. Baczewski opened Poland's first industrial vodka distillery in Lwów."],"where":[],"whereNote":null,"sources":[{"title":"Vodka","url":"https://en.wikipedia.org/wiki/Vodka"},{"title":"Distilled beverage","url":"https://en.wikipedia.org/wiki/Distilled_beverage"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"volleyball","name":"Volleyball","kind":"product","category":"play","title":"How volleyballs are made","url":"https://assemblyline.org/make/volleyball","stations":5,"upstream":53,"downstream":0,"depth":8,"dek":"Inside a volleyball is a rubber balloon wrapped in thread, so the ball stays round when it is pumped up.","answer":"Factories build a volleyball from the inside out. A rubber bladder is molded into a sphere and wrapped in nylon or polyester thread so it stays round. Cover panels, 18 on most balls, are cut and either coated with adhesive for bonding or prepared for stitching. The panels join over the lining, and each ball is inflated and left for 24 hours to reveal leaks before weight and roundness checks.","aka":["beach volleyball","indoor volleyball"],"inputs":["rubber","nylon","polyester","polyurethane","pvc","adhesive","thread"],"uses":[],"grounds":["natural-latex","sulfur","water","crude-oil","air","natural-gas","rock-salt","iron-ore","coal","titanium-ore","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["rubber","nylon","polyester","polyurethane","pvc","adhesive","thread","natural-latex","synthetic-rubber","carbon-black","sulfur","benzene","nitric-acid","ammonia","pet-plastic","propylene","chlorine","water","ethylene","pigment","plasticizer","polyethylene","acrylic","epoxy","paraffin-wax","naphtha","styrene","crude-oil","air","hydrogen","toluene","natural-gas","p-xylene","ethylene-glycol","rock-salt","sulfuric-acid","iron-ore","titanium-dioxide","methanol","phenol","acetone","caustic-soda","coal","oxygen","carbon-dioxide","titanium-ore","coke","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold the bladder","process":"mold","text":"Butyl or latex rubber is molded into the sphere that holds the air. Butyl keeps its pressure for far longer.","inputs":["rubber"]},{"name":"Wind on the lining","process":"assemble","text":"Layers of nylon or polyester thread and cloth wrap the inflated bladder, keeping the ball from going lumpy under pressure.","inputs":["nylon","polyester"]},{"name":"Cut the cover panels","process":"cut","text":"PU, TPU or PVC cover material is cut into precise shapes, then coated with adhesive or readied for the needle according to the ball's grade.","inputs":["polyurethane","pvc"]},{"name":"Bond or stitch the cover","process":"assemble","text":"For match balls the panels are glued straight to the lining, leaving no visible seam. Training balls are machine stitched, almost always in PVC tough enough to hold thread.","inputs":["adhesive","thread"]},{"name":"Inflate and hold","process":"inspect","text":"Every ball is pumped up and left for 24 hours to expose leaks, then checked for roundness and weight against official limits.","inputs":[]}],"facts":["The earliest volleyballs were leather panels over a rubber carcass.","Beach volleyballs are slightly larger than indoor balls, with a coarser texture and lower internal pressure."],"where":[],"whereNote":null,"sources":[{"title":"Sportsmatik: Volley ball, components and how it's made","url":"https://sportsmatik.com/sports-corner/sports-equipage-detail/volley-ball"},{"title":"Volleyball (ball)","url":"https://en.wikipedia.org/wiki/Volleyball_(ball)"},{"title":"How are volleyballs made","url":"https://summitsport.com.au/blogs/articles/how-are-volleyballs-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"rubber","name":"Vulcanized rubber","kind":"material","category":"plastics","title":"How vulcanized rubber is made","url":"https://assemblyline.org/make/rubber","stations":6,"upstream":15,"downstream":30,"depth":7,"dek":"Raw rubber turns soft and sticky in the heat. Sulfur and a hot mold lock its chains together so it stays springy.","answer":"Vulcanized rubber is made by kneading rubber, natural or synthetic, with carbon black, sulfur and other chemicals, shaping the dough in a mold or extruder, and then heating it. Sulfur cross-links tie the long molecules together, so the part keeps its shape and springs back instead of going soft.","aka":["cured rubber","vulcanization","hard rubber"],"inputs":["natural-latex","synthetic-rubber","carbon-black","sulfur"],"uses":["computer-keyboard","vacuum-cleaner","electric-kettle","pencil","shipping-container","tennis-ball","baseball","soccer-ball","ski","snowboard","roller-skates","golf-club","football","volleyball","cricket-bat","dumbbell","treadmill","wheelchair","ladder","wheelbarrow","fire-extinguisher","hiking-boots","high-heels","loudspeaker","inkjet-printer","electric-toothbrush","sneaker","leather-shoe","umbrella"],"grounds":["natural-latex","sulfur","water","crude-oil","air","natural-gas","coal"],"upstreamSlugs":["natural-latex","synthetic-rubber","carbon-black","sulfur","naphtha","benzene","ethylene","styrene","water","crude-oil","air","hydrogen","toluene","natural-gas","coal"],"downstreamSlugs":["computer-keyboard","vacuum-cleaner","electric-kettle","pencil","shipping-container","tennis-ball","baseball","soccer-ball","ski","snowboard","roller-skates","golf-club","football","volleyball","cricket-bat","dumbbell","treadmill","wheelchair","ladder","wheelbarrow","fire-extinguisher","hiking-boots","high-heels","loudspeaker","inkjet-printer","electric-toothbrush","sneaker","leather-shoe","umbrella","laptop"],"steps":[{"name":"Coagulate the latex","process":"separate","text":"Milky latex from rubber trees is mixed with acid so the rubber clumps. The clots are rolled into sheets, washed and dried into the bales that factories buy.","inputs":["natural-latex"]},{"name":"Chew the rubber soft","process":"knead","text":"Heavy rollers or an internal mixer break down the tough bales until they are workable. Natural and synthetic rubber are often blended here.","inputs":["synthetic-rubber"]},{"name":"Mix in fillers and sulfur","process":"mix","text":"Carbon black, sulfur, accelerators and antioxidants are worked into the rubber. The mix is dispersed so evenly that every cubic centimeter behaves the same.","inputs":["carbon-black","sulfur"]},{"name":"Shape the dough","process":"mold","text":"The warm mix is extruded, calendered or pressed into a mold cavity. Not yet vulcanized, it is still soft and could be reshaped.","inputs":[]},{"name":"Heat it to vulcanize","process":"dry","text":"Hot molds or steam heat the part so sulfur bonds form cross-links between the long chains. The rubber turns from sticky dough to a firm, elastic solid that stays flexible.","inputs":[]},{"name":"Trim and test","process":"inspect","text":"Excess rubber flash is trimmed off and samples are checked for hardness and stretch. Vulcanized parts cannot be melted and reshaped.","inputs":[]}],"facts":["The word vulcanization was suggested by William Brockedon, a friend of Thomas Hancock, after Vulcan, the god associated with heat and sulfur.","In the 1830s Charles Goodyear worked to devise a way to strengthen rubber, because tires of the time went soft and sticky in the heat."],"where":[],"whereNote":null,"sources":[{"title":"Vulcanization","url":"https://en.wikipedia.org/wiki/Vulcanization"},{"title":"Natural rubber","url":"https://en.wikipedia.org/wiki/Natural_rubber"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wallpaper","name":"Wallpaper","kind":"product","category":"wood-paper","title":"How wallpaper is made","url":"https://assemblyline.org/make/wallpaper","stations":7,"upstream":67,"downstream":0,"depth":10,"dek":"A rotary wallpaper press can print up to 12 colors in one pass at roughly 80 yards a minute.","answer":"Wallpaper is a paper or fabric backing that gets a base color, then a pattern printed one color at a time from engraved cylinders or screen stencils. Ink dries between colors. A strike-off sample is checked first, and the full run is printed, optionally coated with starch paste, then cut into rolls.","aka":["wallcovering","wall paper"],"inputs":["paper","ink","paint","corn-starch"],"uses":[],"grounds":["water","kaolin","limestone","corn","timber","soybeans","rapeseed","clay","crude-oil","air","titanium-ore","iron-ore","sulfur","sugarcane","rock-salt","coal","natural-gas","sugar-beet","tin-ore","dolomite","manganese-ore","quartz"],"upstreamSlugs":["paper","ink","paint","corn-starch","wood-pulp","water","kaolin","limestone","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","acrylic","tin-can","corn","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","sugarcane","yeast","ethylene","propylene","ammonia","methanol","tinplate","lacquer","rock-salt","hydrogen","benzene","coal","molasses","naphtha","natural-gas","steel","tin","toluene","sugar-beet","pig-iron","magnesium","steel-scrap","manganese","argon","tin-ore","dolomite","silicon","propane","manganese-ore","quartz","charcoal"],"downstreamSlugs":[],"steps":[{"name":"Make the stencil or roller","process":"etch","text":"A designer's sketch is split into one layer per color. For screen printing, each layer is exposed through a photographic negative onto a light-sensitive screen, which hardens everywhere except the pattern.","inputs":[]},{"name":"Check a strike-off","process":"inspect","text":"A few repeats of the pattern are printed as a sample and compared to the design. Only after they are approved does the full run begin.","inputs":["paper","ink"]},{"name":"Lay the base color","process":"coat","text":"The paper backing is rolled with a solid background color. On many grades the backing is made from ground wood or wood pulp.","inputs":["paper","paint"]},{"name":"Print color by color","process":"print","text":"In rotary printing, mesh-covered tubes feed ink through the stencil onto the moving paper. Each tube lays down one color.","inputs":["ink"],"spec":"up to 12 colors"},{"name":"Dry between colors","process":"dry","text":"Each color needs to set before the next one touches it. The choice of solvent in the ink, water or acetone for instance, changes how long the wait is.","inputs":[]},{"name":"Add paste if prepasted","process":"coat","text":"Prepasted rolls get a wet coating of cornstarch or wheat starch that is dried on, and the installer reactivates it with water.","inputs":["corn-starch"]},{"name":"Cut and roll","process":"package","text":"The long printed web is cut to retail lengths and wound into rolls.","inputs":[]}],"facts":["The earliest European wallpapers, from as early as the thirteenth century, were painted images called domino papers.","By about 1885, cylinder printing on wood pulp paper made it cheaper to wallpaper a US house than to paint it."],"where":[],"whereNote":null,"sources":[{"title":"Wallpaper","url":"https://encyclopedia.com/manufacturing/news-wires-white-papers-and-books/wallpaper"},{"title":"Wallpaper","url":"https://en.wikipedia.org/wiki/Wallpaper"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"washing-machine","name":"Washing machine","kind":"product","category":"machines","title":"How washing machines are made","url":"https://assemblyline.org/make/washing-machine","stations":12,"upstream":106,"downstream":0,"depth":10,"dek":"A plastic and cement balance ring of over twenty pounds is what stops a washing machine walking across the floor.","answer":"Coils of zinc-coated steel feed the presses that shape most of a washing machine, while plastic pumps and guards come from injection molds. A rolled and welded drum becomes the spin tub. On the conveyor, workers stack transmission, balance ring and tubs into a module, lift it onto the base with springs, and add motor, controls and cabinet. Each one is filled with water and run.","aka":["washer","clothes washer","front-loader"],"inputs":["sheet-steel","plastic","stainless-steel","aluminum","cement","paint","ball-bearing","steel-wire","electric-motor","printed-circuit-board","copper-wire","cardboard-box"],"uses":[],"grounds":["natural-gas","crude-oil","coal","limestone","clay","gypsum","water","zinc-ore","air","chromite","nickel-ore","bauxite","titanium-ore","iron-ore","sulfur","copper-ore","silica-sand","dolomite","manganese-ore","rock-salt","trona","tin-ore","lead-ore","silver-ore","timber","soybeans","rapeseed","corn","sugarcane","quartz","sugar-beet"],"upstreamSlugs":["sheet-steel","plastic","stainless-steel","aluminum","cement","paint","ball-bearing","steel-wire","electric-motor","printed-circuit-board","copper-wire","cardboard-box","steel","zinc","naphtha","natural-gas","ethylene","propylene","steel-scrap","chromium","nickel","oxygen","argon","crude-oil","coal","petroleum-coke","alumina","limestone","clay","gypsum","water","titanium-dioxide","pigment","acrylic","tin-can","epoxy","copper","fiberglass","photoresist","solder","cardboard","ink","adhesive","pig-iron","magnesium","lime","manganese","zinc-ore","air","sulfuric-acid","hydrogen","propane","chromite","coke","soda-ash","nickel-ore","bauxite","caustic-soda","titanium-ore","chlorine","iron-ore","carbon-black","sulfur","ammonia","methanol","tinplate","lacquer","phenol","acetone","copper-ore","silica-sand","phenolic-resin","tin","lead","silver","wood-pulp","vegetable-oil","ethanol","polyethylene","polyurethane","paraffin-wax","dolomite","silicon","manganese-ore","rock-salt","carbon-dioxide","trona","benzene","formaldehyde","tin-ore","lead-ore","silver-ore","timber","hydrogen-peroxide","soybeans","rapeseed","hexane","corn","sugarcane","yeast","nitric-acid","quartz","charcoal","toluene","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Press the sheet parts","process":"stamp","text":"A press squeezes steel between two halves of a die, feeding straight from the coil where it can. One die alone tends to wrinkle or tear the metal, so most parts pass through several. The steel usually carries a zinc coating against rust.","inputs":["sheet-steel"]},{"name":"Mold the plastic parts","process":"mold","text":"Melted plastic is forced into a steel mold at high pressure, and water running through the mold sets it. Ejector pins push out the part, often leaving small circles you can spot later. Pumps, tub guards and agitators are made this way.","inputs":["plastic"]},{"name":"Roll and weld the drum","process":"weld","text":"Sheet is rolled into a drum and its side is welded and smoothed. An expander stretches it to final shape, and a bottom is welded on. Stainless tubs are polished so they will not snag clothes, and others get a fired-on porcelain coat. One patent describes stamping each water hole and drawing its rim into a small funnel to round off burrs, and another butt welds a front-loader's steel tub the same way.","inputs":["stainless-steel"]},{"name":"Cast the gearbox parts","process":"cast","text":"On belt-driven agitator machines, ingots of aluminum are melted and ladled into die cast molds. Machines then drill the rough castings and shave critical faces. Workers bolt and press in shafts and gears and add a metered dose of oil.","inputs":["aluminum"]},{"name":"Seal the pump","process":"assemble","text":"Robots set the impeller and seals into the cover and body, and heat or vibration fuses the housing shut. Air is then used to check every pump for leaks.","inputs":[]},{"name":"Weight the balance ring","process":"assemble","text":"A plastic ring with metal melted into it for strength receives a fill of cement and is balanced precisely. The finished ring tops twenty pounds and steadies the machine in use.","inputs":["cement"]},{"name":"Powder coat the panels","process":"coat","text":"Parts hang from an overhead conveyor with one electrical charge while a flour-fine powder paint is sprayed with the opposite one, so the two attract. An oven then melts the powder. Some makers buy prepainted steel, which is cheaper but leaves cut edges bare.","inputs":["paint"]},{"name":"Build the tub module","process":"assemble","text":"The wash tub rides a conveyor while the transmission goes onto a bearing bolted to it, along with the balance ring, brake and drive pulley. A hydraulic lift raises the module onto the base, and springs tie the two together. Inside the wash tub, the spin tub bolts on.","inputs":["ball-bearing","steel-wire"]},{"name":"Bolt on motor and pump","process":"assemble","text":"The pump and a bracket bolt to the motor, which gets a shield against leaks. The set is fixed to the base and tied to the module by a belt and hoses. Direct-drive designs leave out the belt.","inputs":["electric-motor"]},{"name":"Wire controls and cabinet","process":"assemble","text":"Controls mount behind a printed panel, and the wiring comes as a single bundle that clips on at one end and runs down to the motor. A robot lowers the heavy cabinet into place, and it is bolted to the base. Many now run on microcontrollers.","inputs":["printed-circuit-board","copper-wire"]},{"name":"Fill and run it","process":"inspect","text":"The finished washer is filled with water and listened to and watched for noise, vibration and visual defects, and its controls are tried. Only after this does the front panel go on.","inputs":[]},{"name":"Crate for the truck","process":"package","text":"A machine opens a flat carton, drops it over the washer, then folds and glues the flaps under pressure. A strap goes around the top because lift trucks carry the crate from there.","inputs":["cardboard-box"]}],"facts":["The last wringer washer built in the United States came out of a Speed Queen plant in Ripon, Wisconsin, in June 1990.","Scrap plastic from washer parts gets reground but goes only into hidden pieces, since its color cannot be held steady.","Most modern European front-loaders have only a cold water connection and heat the water themselves."],"where":[],"whereNote":null,"sources":[{"title":"Washing Machine, How Products Are Made","url":"https://encyclopedia.com/manufacturing/news-wires-white-papers-and-books/washing-machine"},{"title":"US5934110A, Laundry drum for a washing machine and tool for producing the same","url":"https://patents.google.com/patent/US5934110A/en"},{"title":"US7743480B2, Method of manufacturing a drum-type washing machine","url":"https://patents.google.com/patent/US7743480B2/en"},{"title":"Washing machine","url":"https://en.wikipedia.org/wiki/Washing_machine"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"water","name":"Water","kind":"raw","category":"ground","title":"How drinking water is sourced and treated","url":"https://assemblyline.org/make/water","stations":4,"upstream":0,"downstream":608,"depth":0,"dek":"The oldest reliably dated well, dug about 8400 BC on Cyprus, was driven through limestone to reach an aquifer.","answer":"Most municipal water comes from wells tapping underground aquifers, or from rivers and lakes. It is pumped to a treatment plant, where chemicals make fine particles clump together, the clumps settle and are filtered out, and a disinfectant kills germs. Some disinfectant stays in the water to protect it in the pipes.","aka":["fresh water","tap 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from the aquifer","process":"drill","text":"A well is dug, driven or drilled to reach an aquifer, a layer of permeable rock, gravel or sand holding water. A pump lifts the groundwater up the shaft.","inputs":[]},{"name":"Clump and settle","process":"separate","text":"Coagulants neutralize the electric charge on tiny suspended particles so that they stick into larger flakes. In still tanks gravity pulls the flakes to the bottom.","inputs":[]},{"name":"Filter through sand","process":"wash","text":"The clearer water passes through filters that catch what the settling missed. Some plants use slow sand filtration, in which biological processes help clean the water.","inputs":[]},{"name":"Disinfect it","process":"pasteurize","text":"Chlorine, ozone or ultraviolet light kills bacteria, viruses and other pathogens. A residual disinfectant is usually left in the water to keep the pipes clean.","inputs":[]}],"facts":["About 70% of the fresh water used by humans goes to agriculture.","Water covers about 71% of the Earth's surface, but groundwater is only 1.7% of all water.","The oldest reliably dated well is from about 8400 BC in Cyprus."],"where":[],"whereNote":null,"sources":[{"title":"Water","url":"https://en.wikipedia.org/wiki/Water"},{"title":"Water treatment","url":"https://en.wikipedia.org/wiki/Water_treatment"},{"title":"Aquifer","url":"https://en.wikipedia.org/wiki/Aquifer"},{"title":"Water well","url":"https://en.wikipedia.org/wiki/Water_well"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"water-heater","name":"Water heater","kind":"product","category":"machines","title":"How water heaters are made","url":"https://assemblyline.org/make/water-heater","stations":6,"upstream":71,"downstream":0,"depth":10,"dek":"The inside of a water heater tank is coated in glass, and a sacrificial metal rod guards the spots the glass misses.","answer":"A flat steel sheet is rolled into a cylinder, its seam is welded, and top and bottom heads are welded on. Powdered glass is sprayed inside and fired so it fuses to the steel. Heating parts and a sacrificial anode rod are fitted, foam insulation is poured around the tank, and a steel jacket closes it.","aka":["hot water heater","hot water tank","storage water heater"],"inputs":["sheet-steel","glass","magnesium","polyurethane","paint"],"uses":[],"grounds":["silica-sand","limestone","dolomite","water","zinc-ore","air","rock-salt","trona","quartz","coal","timber","crude-oil","titanium-ore","iron-ore","sulfur","manganese-ore","natural-gas","corn","tin-ore","sugarcane","soybeans","rapeseed","clay","sugar-beet"],"upstreamSlugs":["sheet-steel","glass","magnesium","polyurethane","paint","steel","zinc","silica-sand","soda-ash","limestone","dolomite","silicon","propylene","nitric-acid","chlorine","water","titanium-dioxide","pigment","acrylic","tin-can","pig-iron","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","rock-salt","ammonia","carbon-dioxide","trona","quartz","coke","coal","charcoal","timber","naphtha","crude-oil","titanium-ore","iron-ore","carbon-black","sulfur","methanol","tinplate","lacquer","ink","propane","manganese-ore","natural-gas","corn","yeast","hydrogen","tin","ethanol","vegetable-oil","phenolic-resin","molasses","tin-ore","sugarcane","ethylene","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","sugar-beet","benzene","toluene"],"downstreamSlugs":[],"steps":[{"name":"Roll the shell","process":"roll","text":"A flat steel sheet is rolled into a cylinder, and automated welders close its vertical seam in one pass.","inputs":["sheet-steel"]},{"name":"Weld on the heads","process":"weld","text":"Top and bottom heads are welded to the cylinder, and openings are made for the water inlet, outlet and fittings. The tank is pressure tested well above household pressure.","inputs":[]},{"name":"Line it with glass","process":"coat","text":"Powdered glass called frit is sprayed inside the tank, then fired at high temperature so it bonds to itself and the steel. This glass is the barrier that keeps water from rusting the steel.","inputs":["glass"]},{"name":"Fit the heating parts","process":"assemble","text":"Electric models get heating elements screwed into the tank wall, plus a thermostat. A sacrificial anode rod hangs inside, corroding in place of the tank wherever the glass left small gaps.","inputs":["magnesium"]},{"name":"Pour in foam insulation","process":"mold","text":"Liquid chemicals that expand into foam are poured into the space between the tank and a larger shell. They rise and harden around the tank.","inputs":["polyurethane"]},{"name":"Close the jacket","process":"assemble","text":"A steel jacket with a painted finish closes the unit.","inputs":["sheet-steel","paint"]}],"facts":["Almost all water heaters have been made the same basic way for the past 80 years.","The glass lining goes on the same way as the enamel on ornate dinnerware: colored powder fired until it fuses.","Compact heaters can skip the side seam, using a one-piece body deep-drawn from a steel plate."],"where":[],"whereNote":null,"sources":[{"title":"A look inside a hot water heater","url":"https://www.waterheaterrescue.com/water-heaters-101/inside-a-hot-water-heater.html"},{"title":"DIY Hot Water Heater Tank: Materials and Build Methods","url":"https://watersystemwiki.com/diy-hot-water-heater-tank-materials/"},{"title":"What are water heater tanks made of?","url":"https://www.waterheatersnow.com/blog/what-are-water-heater-tanks-made-of"},{"title":"Compact electric water heater (US patent 5574822)","url":"https://patents.google.com/patent/US5574822"},{"title":"Water heating","url":"https://en.wikipedia.org/wiki/Water_heating"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wet-wipes","name":"Wet wipes","kind":"product","category":"body-health","title":"How wet wipes are made","url":"https://assemblyline.org/make/wet-wipes","stations":5,"upstream":22,"downstream":0,"depth":7,"dek":"Nine in ten wet wipes are plastic fabric, which is why many brands cannot really be flushed.","answer":"A wet wipe is a sheet of nonwoven fabric soaked in a cleansing liquid. About ninety percent of wipes use polyester or polypropylene. Fibers are laid into a web and bonded without weaving, cut into sheets, then saturated with water or another liquid containing preservatives, and folded into packs.","aka":["baby wipes","moist towelettes","disposable wipes"],"inputs":["polyester","polypropylene","water","plastic"],"uses":[],"grounds":["water","natural-gas","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["polyester","polypropylene","water","plastic","pet-plastic","propylene","naphtha","natural-gas","ethylene","p-xylene","ethylene-glycol","crude-oil","hydrogen","oxygen","carbon-dioxide","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Form the fiber web","process":"spin","text":"Staple fibers are spun, cut to a few centimeters, blended and opened, then dispersed on a conveyor belt and spread into an even web.","inputs":["polyester","polypropylene"]},{"name":"Bond the web","process":"press","text":"The loose web is bound into fabric by chemical, mechanical, heat or solvent treatment, with no weaving. Spunlace bonding tangles the fibers with water jets.","inputs":[]},{"name":"Cut the sheets","process":"cut","text":"The roll of nonwoven fabric is cut and folded into wipe-sized sheets.","inputs":[]},{"name":"Saturate with lotion","process":"coat","text":"The fabric is moistened with water or other liquid such as isopropyl alcohol. Softeners, lotions or perfume adjust feel and scent, and preservatives such as methylisothiazolinone prevent bacteria and fungi growing in the package.","inputs":["water"]},{"name":"Seal in packs","process":"fill","text":"Sheets are packed in sealed tubs or pouches with dispensing openings so they stay moist.","inputs":["plastic"]}],"facts":["The first wipes marketed specifically as baby wipes, Huggies and Pampers, appeared in 1990.","In 2013, Consumer Reports found that none of the leading flushable wipes passed its tests.","In the early 1970s the American Can Company test-marketed Fresh'n, a flushable moist toilet towel, in Omaha and Phoenix."],"where":[],"whereNote":null,"sources":[{"title":"Wet wipe","url":"https://en.wikipedia.org/wiki/Wet_wipe"},{"title":"Nonwoven fabric","url":"https://en.wikipedia.org/wiki/Nonwoven_fabric"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wheat","name":"Wheat","kind":"raw","category":"farm","title":"How wheat is grown and harvested","url":"https://assemblyline.org/make/wheat","stations":3,"upstream":0,"downstream":23,"depth":0,"dek":"Wheat covers more farmland than any other food crop, about 219.5 million hectares in 2024.","answer":"Wheat is a grass sown as seed in tilled fields and left to grow until the heads turn golden and dry. A combine harvester cuts the crop, shakes the grain loose from the straw and cleans it in one pass. The grain is then dried and moved to storage, ready to be milled into flour.","aka":["wheat farming","wheat crop","wheat harvest","grain"],"inputs":[],"uses":["flour","soy-sauce","vodka","gin","koji"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["flour","soy-sauce","vodka","gin","koji","bread","instant-noodles","tortilla","croissant","donut","pretzel","sandwich-cookie","chicken-nuggets","frozen-pizza","bagel","baguette","sourdough","crackers","fish-sticks","modeling-clay","licorice","cake-mix","sake"],"steps":[{"name":"Drill the seed","process":"grow","text":"Seed is sown in prepared fields, in autumn for winter varieties or in spring for the spring kind. Wheat grows on a larger area of land than any other food crop.","inputs":[]},{"name":"Grow to a golden ear","process":"grow","text":"Leaves unfold from the shoot one by one until the plant flowers. The last leaf to appear, the flag leaf, is denser than the others and supplies most of the carbohydrate that fills the developing ear.","inputs":[]},{"name":"Combine the crop","process":"harvest","text":"A combine harvester cuts the standing crop, threshes the grain out of the ears and blows the chaff away. In domesticated wheat the grains stay on the ear until threshing, but in wild wheat the ear shatters and scatters them.","inputs":[]}],"facts":["World trade in wheat is greater than that of all other crops combined.","The earliest known wheat with enough gluten for yeasted bread comes from a granary at Assiros in Macedonia, dated to 1350 BC.","Wheat was first cultivated in the Fertile Crescent around 9600 BC."],"where":[{"place":"China, India and Russia combined","share":"42% of world output"}],"whereNote":"2024, share of the 799 million tonnes of wheat produced worldwide.","sources":[{"title":"Wheat","url":"https://en.wikipedia.org/wiki/Wheat"},{"title":"Combine harvester","url":"https://en.wikipedia.org/wiki/Combine_harvester"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wheelbarrow","name":"Wheelbarrow","kind":"product","category":"hardware","title":"How wheelbarrows are made","url":"https://assemblyline.org/make/wheelbarrow","stations":9,"upstream":83,"downstream":0,"depth":10,"dek":"At one UK plant, a sensor finds the weld seam in every tube before a robot-fed machine bends it into a frame.","answer":"A steel wheelbarrow starts as two separate jobs. A hydraulic press deep-draws sheet steel into a tray, while a bender curves steel tube into a frame. Both get punched or trimmed, degreased, and coated with electrostatic paint baked on in an oven. A rubber tire goes on the wheel, and many barrows leave in a box for the buyer to bolt together.","aka":["garden barrow","builder's barrow"],"inputs":["sheet-steel","steel-pipe","paint","rubber","bolt","cardboard-box"],"uses":[],"grounds":["water","natural-latex","sulfur","zinc-ore","air","titanium-ore","iron-ore","crude-oil","limestone","dolomite","manganese-ore","natural-gas","rock-salt","coal","timber","soybeans","rapeseed","clay","corn","sugarcane","quartz","tin-ore","sugar-beet"],"upstreamSlugs":["sheet-steel","steel-pipe","paint","rubber","bolt","cardboard-box","steel","zinc","water","titanium-dioxide","pigment","acrylic","tin-can","natural-latex","synthetic-rubber","carbon-black","sulfur","steel-wire","cardboard","ink","adhesive","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","zinc-ore","air","sulfuric-acid","titanium-ore","chlorine","coke","iron-ore","propylene","ammonia","methanol","tinplate","lacquer","naphtha","benzene","ethylene","styrene","crude-oil","wood-pulp","vegetable-oil","phenolic-resin","ethanol","polyethylene","epoxy","polyurethane","paraffin-wax","limestone","dolomite","silicon","propane","manganese-ore","natural-gas","rock-salt","coal","tin","hydrogen","toluene","timber","caustic-soda","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","corn","sugarcane","yeast","acetone","nitric-acid","quartz","charcoal","tin-ore","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Draw the tray","process":"stamp","text":"A hydraulic press deep-draws sheet steel into a dished tray. Rupture and wrinkling are the faults that most often spoil a draw this deep.","inputs":["sheet-steel"]},{"name":"Trim and bead the rim","process":"cut","text":"A machine trims the drawn tray's uneven edge and rolls a bead along it. An early patent from the Toledo Wheelbarrow Company did both jobs on one machine.","inputs":[]},{"name":"Bend the frame tubes","process":"press","text":"At Walsall Wheelbarrow, 30 mm steel tube up to two meters long is swaged, then fed one piece at a time to a bending machine. First, a magnetic sensor finds the tube's weld seam and turns it to the best angle, because the seam changes how the tube springs back.","inputs":["steel-pipe"],"spec":"30 mm tube"},{"name":"Punch the bolt holes","process":"stamp","text":"Holes go in after bending, on a separate machine, and never through the seam. Legs and braces are cut from steel strip by sharp dies in big presses and punched the same way.","inputs":[]},{"name":"Paint and bake","process":"coat","text":"A degreasing solution cleans the steel, which then dries. Steel and paint get opposite electrical charges, so the paint pulls evenly onto every surface before an oven bakes it on.","inputs":["paint"]},{"name":"Fit the tire","process":"assemble","text":"A rubber tire, molded elsewhere, is placed around a wheel of steel or plastic.","inputs":["rubber"]},{"name":"Check the fit","process":"inspect","text":"Steel parts are compared with a known-good reference part, and hole position matters most. A sample barrow may be built, loaded and pushed around as a test.","inputs":[]},{"name":"Weigh out the bolts","process":"assemble","text":"Nobody needs to count them. A batch of the correct weight on an accurate scale holds the correct number of bolts for one kit.","inputs":["bolt"]},{"name":"Box the kit","process":"package","text":"Most barrows ship unassembled in a strong cardboard box, with instructions, and take far less space that way. Some lines instead weld or bolt the tray to the frame in the factory.","inputs":["cardboard-box"]}],"facts":["A tomb mural in Chengdu, China, dated 118 AD, shows a man pushing a wheelbarrow.","Walsall Wheelbarrow reported that a second automated tube-bending cell helped lift its capacity from 1800 to 3500 wheelbarrows a day.","A flat-pack barrow's frame can come in three parts so that the whole thing fits in the trunk of a car."],"where":[],"whereNote":null,"sources":[{"title":"Wheelbarrow","url":"https://en.wikipedia.org/wiki/Wheelbarrow"},{"title":"Wheelbarrow, How Products Are Made, Encyclopedia.com","url":"https://www.encyclopedia.com/science-and-technology/technology/technology-terms-and-concepts/wheelbarrow"},{"title":"Robots automate wheelbarrow manufacturing, Automation.com","url":"https://www.automation.com/en-us/articles/2016-1/robots-automate-wheelbarrow-manufacturing"},{"title":"Numerical investigation of an extra-deep drawing process with industrial parameters","url":"https://fracturae.com/index.php/fis/article/view/4624"},{"title":"Machine for trimming and beading wheelbarrow-trays (US888429A)","url":"https://patents.google.com/patent/US888429A/en"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wheelchair","name":"Wheelchair","kind":"product","category":"body-health","title":"How wheelchairs are made","url":"https://assemblyline.org/make/wheelchair","stations":6,"upstream":47,"downstream":0,"depth":8,"dek":"The first lightweight folding wheelchair was built in a garage in 1933 by two engineers, one hurt in a mine accident.","answer":"A manual wheelchair is a frame, seat, footplates and wheels. Lengths of steel or aluminum tube are cut, drilled and bent, then joined in jigs into a frame. Seat and footrest parts are drilled and fitted, brake and wheel assemblies are added, and the chair is checked for alignment before it is packed. Sample chairs go through drop and rough-terrain tests.","aka":["manual wheelchair","mobility chair"],"inputs":["steel","aluminum","plastic","polyurethane","rubber"],"uses":[],"grounds":["crude-oil","coal","natural-gas","water","natural-latex","sulfur","iron-ore","limestone","air","dolomite","manganese-ore","bauxite","rock-salt","quartz","timber"],"upstreamSlugs":["steel","aluminum","plastic","polyurethane","rubber","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","crude-oil","coal","petroleum-coke","alumina","naphtha","natural-gas","ethylene","propylene","nitric-acid","chlorine","water","natural-latex","synthetic-rubber","carbon-black","sulfur","iron-ore","coke","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","bauxite","caustic-soda","hydrogen","ammonia","rock-salt","benzene","styrene","quartz","charcoal","timber","toluene"],"downstreamSlugs":[],"steps":[{"name":"Cut the tubing","process":"cut","text":"Lengths of extruded aluminum or steel tube are cut on drop-saws to exact size. CNC mills make smaller parts from bar and plate stock.","inputs":["steel","aluminum"]},{"name":"Drill and bend the parts","process":"machine","text":"Cut pieces are set up in jigs on drill presses and drilled, and sheet parts for the handles are cut and shaped. Jigs keep the holes in the same place on every chair.","inputs":[]},{"name":"Join the frame","process":"weld","text":"The tubes are joined into a chassis. Folding chairs add a cross brace so the sides can close together, while rigid chairs stay as one piece.","inputs":[]},{"name":"Build the seat unit","process":"assemble","text":"Seat, back and footrest blanks are drilled for adjustment and fixed to the seat framing. Handles, straps and brake parts go on next, and a cushion or sling goes on the seat.","inputs":["plastic","polyurethane"]},{"name":"Fit the wheels","process":"assemble","text":"The seat unit is joined to the chassis with footplates and front wheels. Large rear wheels look much like bicycle wheels, with a push-rim for the hands and solid, pneumatic or gel-filled tires.","inputs":["rubber"]},{"name":"Check and test","process":"inspect","text":"Each chair goes through an alignment check. Periodically one is run through timed tests on simulated rough terrain and through drop tests.","inputs":[]}],"facts":["One Australian charity's volunteers build over 400 rough-terrain wheelchairs for children every month, testing them to World Health Organization guidelines.","In 1655 the watchmaker Stephan Farffler built a self-propelling chair with cranks and cogwheels.","In 1887 Atlantic City rented out rolling chairs on the Boardwalk, and healthy tourists took them too."],"where":[],"whereNote":null,"sources":[{"title":"Wheelchair","url":"https://en.wikipedia.org/wiki/Wheelchair"},{"title":"Everest & Jennings","url":"https://en.wikipedia.org/wiki/Everest_%26_Jennings"},{"title":"Manufacturing process (Wheelchairs for Kids)","url":"https://wheelchairsforkids.org/what-we-do/manufacturing-process/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"whiskey","name":"Whiskey","kind":"product","category":"drink","title":"How whiskey is made","url":"https://assemblyline.org/make/whiskey","stations":7,"upstream":26,"downstream":0,"depth":6,"dek":"Up to 45 litres of whisky can vanish from a cask in four years, and distillers call that loss the angel's share.","answer":"Whiskey is distilled beer. Grain is malted or cooked, mashed into a sweet liquid, and fermented with yeast. The weak, beer-like wash is boiled in a still, and the vapor is condensed into clear spirit. That spirit is then matured in oak casks, where it picks up color and flavor, before being diluted and bottled.","aka":["whisky","scotch","bourbon","rye whiskey"],"inputs":["barley","water","corn","malted-barley","yeast","lumber","glass-bottle"],"uses":[],"grounds":["barley","water","corn","timber","silica-sand","limestone","sugarcane","sugar-beet","rock-salt","trona","natural-gas","air","crude-oil"],"upstreamSlugs":["barley","water","corn","malted-barley","yeast","lumber","glass-bottle","molasses","timber","silica-sand","soda-ash","limestone","polyethylene","sugarcane","sugar-beet","rock-salt","ammonia","carbon-dioxide","lime","trona","ethylene","natural-gas","air","naphtha","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Sprout and dry the grain","process":"dry","text":"For malt whisky, barley is soaked, allowed to sprout and then dried with hot air to halt germination. Sprouting makes the enzymes that will convert starch into sugar.","inputs":["barley"],"spec":"three days of soaking"},{"name":"Mash in hot water","process":"mix","text":"The ground malt is stirred into hot water in a mash tun, and its enzymes turn starch into sugar. Bourbon starts with a mash that is at least 51% corn.","inputs":["water","corn","malted-barley"]},{"name":"Ferment to a wash","process":"ferment","text":"Yeast is added to the sweet liquid, which then ferments into a mildly alcoholic liquid called wash. It resembles a strong beer, and needs to go to the still before it spoils.","inputs":["yeast"]},{"name":"Boil it in the still","process":"refine","text":"The wash is heated in a copper pot still or a column still. Alcohol boils off before most of the water, and the vapor is condensed. Distillers keep the middle of the run, called the heart, and send the first and last portions back. Copper pulls out sulfur compounds that would taste unpleasant.","inputs":[],"spec":"70–80% ABV off a pot still"},{"name":"Fill the oak casks","process":"fill","text":"The clear spirit goes into casks. American whiskey must be aged in new charred oak, while many Scotch casks are reused. Oak adds vanillin and other compounds that give color and flavor.","inputs":["lumber"]},{"name":"Wait for maturation","process":"dry","text":"Over the years, the spirit extracts compounds from the wood, loses some of its harshness and slowly evaporates. Scotch whisky must be matured in oak casks in Scotland for a minimum of three years.","inputs":[],"spec":"3 years minimum for Scotch"},{"name":"Blend, dilute and bottle","process":"fill","text":"Casks of different ages are vatted and diluted with water to bottling strength, commonly 40% alcohol by volume. Whisky does not age further once it is in the bottle.","inputs":["water","glass-bottle"]}],"facts":["Whisky takes its name from the Gaelic word for water, uisce or uisge.","A column still can reach a vapor strength of 95.6% alcohol, which is the most that alcohol and water can reach by simple distillation.","Aeneas Coffey patented his column still in 1831, making distillation cheaper and more efficient."],"where":[],"whereNote":null,"sources":[{"title":"Whisky","url":"https://en.wikipedia.org/wiki/Whisky"},{"title":"Malting","url":"https://en.wikipedia.org/wiki/Malting"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"white-chocolate","name":"White chocolate","kind":"product","category":"food","title":"How white chocolate is made","url":"https://assemblyline.org/make/white-chocolate","stations":7,"upstream":21,"downstream":0,"depth":6,"dek":"White chocolate has no cocoa powder in it at all. It is cocoa butter, sugar and milk.","answer":"Makers press the fat out of cocoa beans as cocoa butter, and the dark solids go elsewhere. The butter is deodorized, then mixed with sugar, milk solids and flavor into a paste. Steel rollers grind the paste to powder, a conche kneads it warm for hours, and tempering sets the crystal that gives a glossy snap.","aka":["white choc","cocoa butter chocolate"],"inputs":["cocoa-butter","sugar","powdered-milk","vanilla-extract"],"uses":[],"grounds":["cocoa-beans","sugarcane","sugar-beet","water","raw-milk","vanilla-pods","limestone","corn","natural-gas","crude-oil"],"upstreamSlugs":["cocoa-butter","sugar","powdered-milk","vanilla-extract","cocoa-beans","sugarcane","sugar-beet","water","lime","raw-milk","vanilla-pods","ethanol","limestone","corn","yeast","ethylene","molasses","naphtha","natural-gas","crude-oil","hydrogen"],"downstreamSlugs":[],"steps":[{"name":"Deodorize the butter","process":"refine","text":"Pure cocoa butter pressed from the bean can taste unpleasant. Before use it is partly deodorized with steam under vacuum or with solvents, but not fully, or it would lose all its taste.","inputs":["cocoa-butter"]},{"name":"Mix the base","process":"mix","text":"Cocoa butter, sugar, milk solids, an emulsifier such as soy lecithin and flavoring are mixed into a rough paste. Vanilla is the usual flavor.","inputs":["sugar","powdered-milk","vanilla-extract"]},{"name":"Refine with steel rollers","process":"roll","text":"The paste passes through large steel rollers set at ever narrower gaps, which crush it to a dry powder with tiny particles.","inputs":[]},{"name":"Conche it warm","process":"knead","text":"A conching machine mixes and kneads the chocolate for hours, changing its flavor and texture. White chocolate is conched cooler than any other type, because heat triggers Maillard browning that adds off flavors.","inputs":[],"spec":"40 to 50 °C"},{"name":"Standardize the flow","process":"mix","text":"Flavorings, emulsifiers or extra cocoa butter are added to set the viscosity and taste, so the batch works in automatic molding or coating equipment.","inputs":[]},{"name":"Temper it","process":"chill","text":"Chocolate is cooled until cocoa butter begins to crystallize, then warmed to melt the unstable crystals and leave only the stable ones. White chocolate tempers at temperatures lower than dark chocolate and needs longer cooling because of its milk fat.","inputs":[]},{"name":"Mold and wrap","process":"mold","text":"Tempered chocolate is poured into molds, cooled until set and wrapped.","inputs":[]}],"facts":["International standards require white chocolate to hold at least 20 percent cocoa butter and 14 percent milk solids.","The Oxford English Dictionary traces the term white chocolate to a December 1917 issue of Scientific American.","White chocolate is the most challenging type for manufacturers because it is soft and thick."],"where":[],"whereNote":null,"sources":[{"title":"White chocolate","url":"https://en.wikipedia.org/wiki/White_chocolate"},{"title":"Cocoa butter","url":"https://en.wikipedia.org/wiki/Cocoa_butter"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"white-rice","name":"White rice","kind":"product","category":"food","title":"How white rice is made","url":"https://assemblyline.org/make/white-rice","stations":6,"upstream":1,"downstream":0,"depth":1,"dek":"White rice is brown rice with its bran and germ scoured off, a step that takes several machines in a row.","answer":"Harvested rice is threshed and dried quickly so it does not mold. A mill then cleans it, removes the husk, separates out the brown rice, and polishes off the bran and germ. Grading machines sort whole grains from broken ones. Parboiled rice is steamed before milling, which pushes vitamins into the grain's white center.","aka":["polished rice","milled rice"],"inputs":["rice"],"uses":[],"grounds":["rice"],"upstreamSlugs":["rice"],"downstreamSlugs":[],"steps":[{"name":"Thresh the harvest","process":"harvest","text":"Rice is ready to cut when its moisture is 20 to 25 percent. Combines reap it, and threshing separates the grain from the stalks.","inputs":["rice"],"spec":"20 to 25% moisture"},{"name":"Dry it fast","process":"dry","text":"The grain is dried as soon as possible to a moisture level that keeps mold away. Traditionally this meant spreading it on mats in the sun.","inputs":[]},{"name":"Clean the paddy","process":"separate","text":"At the mill, the unmilled grain, called paddy, passes over screens and winnowing fans to remove stalks, stones and dust.","inputs":[]},{"name":"Remove the husk","process":"machine","text":"Dehusking machines peel off the inedible husk. What comes out is brown rice, still wearing its bran and germ.","inputs":[]},{"name":"Polish off the bran","process":"grind","text":"Further milling rubs away the bran and germ, grain by grain, producing successively whiter products until the rice is white.","inputs":[]},{"name":"Grade and bag","process":"package","text":"Grading separates whole grains from broken ones, and the rice is weighed and bagged.","inputs":[]}],"facts":["Only about 8 percent of the world's rice is traded internationally.","Parboiled rice is steamed in its husk first, which hardens the grain and moves vitamins and minerals into the part that survives milling."],"where":[],"whereNote":null,"sources":[{"title":"Rice","url":"https://en.wikipedia.org/wiki/Rice"},{"title":"Brown rice","url":"https://en.wikipedia.org/wiki/Brown_rice"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"whitefish","name":"Whitefish","kind":"raw","category":"farm","title":"How whitefish is caught","url":"https://assemblyline.org/make/whitefish","stations":5,"upstream":0,"downstream":2,"depth":0,"dek":"A quarter of US Alaska pollock becomes imitation crab. Close to half is fillets, many headed for fish sticks.","answer":"Whitefish is a trade term for lean, pale fish such as cod, haddock, hake and pollock, which store most of their oil in the organs, away from the flesh. Trawlers tow funnel-shaped nets through the water, then gut and chill the catch fast. Fillets are frozen into blocks that factories later saw into fish sticks.","aka":["white fish","Alaska pollock","cod","haddock","hake","groundfish"],"inputs":[],"uses":["imitation-crab","fish-sticks"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["imitation-crab","fish-sticks"],"steps":[{"name":"Tow the funnel net","process":"harvest","text":"Trawlers pull a large cone-shaped net through the mid-water for pollock, or along the seabed for bottom-dwelling species. Fish collect in the closed tail of the net. In the Alaska pollock fishery, less than 1 percent of the catch is other species.","inputs":[]},{"name":"Bleed, gut and wash","process":"wash","text":"Crews or factory ships bleed, gut and wash the fish. The exact order depends on the species, the fishing gear and how long the vessel stays at sea.","inputs":[]},{"name":"Chill right away","process":"chill","text":"Fish are cooled to about 0 °C with circulating cold air, boxed ice or slurry ice, or frozen below −18 °C. Lean flesh is perishable, and temperature is the main control on spoilage.","inputs":[]},{"name":"Fillet the catch","process":"cut","text":"Machines and workers cut the fillets from the frame. Trim pieces are kept as well, either minced for cheaper products or washed and pulverized into surimi paste.","inputs":[]},{"name":"Freeze into blocks","process":"chill","text":"Fillets are layered into a block mold and deep-frozen. Minced fish comes in industry-standard 7.5-kilogram blocks. These ship worldwide as raw material for breaded and battered products.","inputs":[]}],"facts":["Alaska pollock is the world's second most important fish species by total catch, after the Peruvian anchoveta.","Fish sticks were launched commercially in 1953 under the Birds Eye label.","British shoppers were offered herring fingers and a bland cod control, and overwhelmingly chose the cod."],"where":[],"whereNote":null,"sources":[{"title":"Whitefish (fisheries term)","url":"https://en.wikipedia.org/wiki/Whitefish_(fisheries_term)"},{"title":"Alaska pollock","url":"https://en.wikipedia.org/wiki/Alaska_pollock"},{"title":"Alaska pollock (NOAA Fisheries)","url":"https://www.fisheries.noaa.gov/species/alaska-pollock"},{"title":"Fish processing","url":"https://en.wikipedia.org/wiki/Fish_processing"},{"title":"Trawling","url":"https://en.wikipedia.org/wiki/Trawling"},{"title":"Fish finger","url":"https://en.wikipedia.org/wiki/Fish_finger"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wifi-router","name":"Wi-Fi router","kind":"product","category":"electronics","title":"How Wi-Fi routers are made","url":"https://assemblyline.org/make/wifi-router","stations":7,"upstream":92,"downstream":0,"depth":10,"dek":"One router maker stocks over 4,500 kinds of parts and laser-engraves a QR code on every circuit board.","answer":"A router starts as a bare board of etched copper. Surface-mount machines place the chips, an oven reflows the solder, and cameras and X-rays look for bad joints. Firmware is then loaded and the radio calibrated for signal strength. After functional tests, the board and antennas go into a housing, and the unit is labeled and boxed with its power adapter.","aka":["wireless router","WiFi router","home router"],"inputs":["printed-circuit-board","microchip","memory-chip","solder","abs-plastic","copper","cardboard-box"],"uses":[],"grounds":["air","copper-ore","water","silica-sand","limestone","quartz","tin-ore","crude-oil","coal","gold-ore","lead-ore","silver-ore","zinc-ore","natural-gas","iron-ore","sulfur","rock-salt","trona","bauxite","titanium-ore","timber","soybeans","rapeseed","clay","corn","sugarcane","sugar-beet"],"upstreamSlugs":["printed-circuit-board","microchip","memory-chip","solder","abs-plastic","copper","cardboard-box","fiberglass","epoxy","photoresist","silicon-wafer","oxygen","tin","aluminum","gold","nitrogen","lead","silver","naphtha","propylene","ammonia","air","benzene","ethylene","styrene","pigment","copper-ore","water","sulfuric-acid","cardboard","ink","adhesive","silica-sand","limestone","soda-ash","phenol","acetone","chlorine","caustic-soda","phenolic-resin","polysilicon","quartz","argon","tin-ore","coke","crude-oil","coal","petroleum-coke","alumina","gold-ore","lime","zinc","lead-ore","silver-ore","zinc-ore","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","carbon-black","sulfur","wood-pulp","vegetable-oil","ethanol","polyethylene","acrylic","polyurethane","paraffin-wax","rock-salt","carbon-dioxide","trona","formaldehyde","silicon","hydrochloric-acid","trichlorosilane","bauxite","titanium-ore","timber","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","corn","sugarcane","yeast","methanol","nitric-acid","charcoal","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Etch the bare board","process":"etch","inputs":["printed-circuit-board"],"text":"Copper layers on a substrate are etched into circuit paths, holes are drilled and plated, and a solder mask and printed labels go on. One maker then laser-engraves a QR code on each board so any flaw can be traced."},{"name":"Check incoming parts","process":"inspect","inputs":[],"text":"Parts from vendors around the world are checked on arrival. Delicate ones wait in cupboards with controlled temperature and humidity before reaching the line."},{"name":"Place and reflow chips","process":"assemble","inputs":["microchip","memory-chip","solder"],"text":"Automated lines set resistors, capacitors and processors on the board, and a reflow oven melts the paste. Bigger connectors go through drilled holes. 3D paste checks, optical inspection and X-rays of suspect joints catch defects."},{"name":"Load and calibrate firmware","process":"assemble","inputs":[],"text":"The control software is written into memory so the unit can manage channels, encryption and traffic. Robots can do the programming and calibration, tuning signal strength and range."},{"name":"Run functional tests","process":"inspect","inputs":[],"text":"Each unit is checked for Wi-Fi connection, signal strength and data throughput. Samples also face extreme heat and humidity, plus compliance tests such as FCC and CE."},{"name":"Close up, mount antennas","process":"assemble","inputs":["abs-plastic","copper"],"text":"The board goes into a protective housing, and internal or external antennas are connected. One plant uses eight six-axis robots on its assembly line for steps like this."},{"name":"Label and box","process":"package","inputs":["cardboard-box"],"text":"A label carries the serial number and compliance marks. The unit is packed with its power adapter, mounting hardware and manual, and at one plant a robot does the packing."}],"facts":["At Teltonika's plant in Vilnius, robots increased assembly speed at least fivefold, according to the company.","Many routers connect their Ethernet ports through a switch built right into the main system-on-a-chip."],"where":[],"whereNote":null,"sources":[{"title":"What does it take to build a router?","url":"https://teltonika-networks.com/newsroom/what-does-it-take-to-build-a-router"},{"title":"Unveiling the Production Process Behind Wi-Fi Access Points","url":"https://todahika.com/news/unveiling-the-production-process-behind-wi-fi-access-points"},{"title":"Wireless router","url":"https://en.wikipedia.org/wiki/Wireless_router"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wind-turbine","name":"Wind turbine","kind":"product","category":"machines","title":"How wind turbines are made","url":"https://assemblyline.org/make/wind-turbine","stations":6,"upstream":69,"downstream":0,"depth":9,"dek":"The biggest offshore turbines have blades up to 153 meters long and generate up to 26 megawatts.","answer":"A wind turbine is built from three main groups of parts. Blades are laid up from glass fiber composites, sometimes with carbon fiber, in huge molds. The tower is rolled and welded from steel. The nacelle on top holds a gearbox and generator, or a direct-drive generator with permanent magnets. Everything is trucked or shipped to site and lifted into place.","aka":["wind generator","windmill turbine","wind power turbine"],"inputs":["fiberglass","carbon-fiber","epoxy","steel","copper-wire","neodymium-magnet","printed-circuit-board"],"uses":[],"grounds":["silica-sand","limestone","air","rare-earth-ore","rock-salt","water","trona","crude-oil","natural-gas","iron-ore","dolomite","manganese-ore","copper-ore","nickel-ore","zinc-ore","corn","sulfur","coal","quartz","timber","tin-ore","lead-ore","silver-ore","sugarcane","sugar-beet"],"upstreamSlugs":["fiberglass","carbon-fiber","epoxy","steel","copper-wire","neodymium-magnet","printed-circuit-board","silica-sand","limestone","soda-ash","propylene","ammonia","air","phenol","acetone","chlorine","caustic-soda","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","copper","rare-earth-ore","nickel","zinc","photoresist","solder","rock-salt","water","carbon-dioxide","trona","naphtha","crude-oil","natural-gas","benzene","sulfuric-acid","iron-ore","coke","dolomite","silicon","propane","manganese-ore","copper-ore","nickel-ore","zinc-ore","phenolic-resin","tin","lead","silver","corn","yeast","hydrogen","toluene","sulfur","coal","quartz","charcoal","timber","formaldehyde","tin-ore","lead-ore","silver-ore","molasses","methanol","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Lay up the blades","process":"laminate","text":"Layers of glass fiber, sometimes with stiffer carbon fiber, are soaked in resin inside long molds and cured into hollow blade shells.","inputs":["fiberglass","carbon-fiber","epoxy"]},{"name":"Roll the tower sections","process":"roll","text":"Steel plate is rolled into tubes and welded into tower sections. Average hub height of onshore turbines in the U.S. is 103 meters.","inputs":["steel"]},{"name":"Cast the hub and frame","process":"cast","text":"The heavy hub that holds the blades, and the main frame, are cast from iron or steel.","inputs":["steel"]},{"name":"Build the generator","process":"assemble","text":"Copper windings, and in direct-drive designs permanent magnets using rare earths, are built into the generator. A geared design adds a gearbox that turns slow blade rotation into fast shaft rotation.","inputs":["copper-wire","neodymium-magnet"]},{"name":"Assemble the nacelle","process":"assemble","text":"Generator, gearbox, yaw drive and control electronics are bolted into the housing that sits atop the tower.","inputs":["printed-circuit-board"]},{"name":"Raise it on site","process":"assemble","text":"Cranes stack the tower, lift the nacelle and bolt on the rotor. The yaw system turns the whole head to face the wind.","inputs":[]}],"facts":["Onshore turbines reach up to 15 MW, with blades up to 131 meters long.","In 1908, 72 wind-driven electric generators from 5 kW to 25 kW operated in the United States.","Gearless turbines are sometimes preferred because they eliminate a part that wears."],"where":[],"whereNote":null,"sources":[{"title":"Wind turbine","url":"https://en.wikipedia.org/wiki/Wind_turbine"},{"title":"Electric motor","url":"https://en.wikipedia.org/wiki/Electric_motor"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"window-glass","name":"Window glass","kind":"product","category":"minerals","title":"How window glass is made","url":"https://assemblyline.org/make/window-glass","stations":7,"upstream":23,"downstream":7,"depth":5,"dek":"Window glass is poured onto a lake of molten tin, which is why it comes out flat with no polishing.","answer":"Most window glass is float glass. Sand, soda ash and limestone are melted at about 1,500 °C and poured onto a long bath of molten tin. The glass spreads into a ribbon with perfectly smooth faces, then travels through a cooling kiln about 100 m long. Machines at the far end cut the ribbon into panes.","aka":["float glass","flat glass","glass pane"],"inputs":["silica-sand","soda-ash","limestone","dolomite","tin","nitrogen","hydrogen"],"uses":["mirror","skyscraper","windshield","double-glazed-window"],"grounds":["silica-sand","limestone","dolomite","rock-salt","water","trona","tin-ore","air","natural-gas","corn","coal","sugarcane","sugar-beet"],"upstreamSlugs":["silica-sand","soda-ash","limestone","dolomite","tin","nitrogen","hydrogen","rock-salt","water","ammonia","carbon-dioxide","lime","trona","tin-ore","coke","air","natural-gas","corn","yeast","coal","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["mirror","skyscraper","windshield","double-glazed-window","car","electric-car","aluminum-window-frame"],"steps":[{"name":"Batch the raw materials","process":"mix","text":"Sand, soda ash, limestone and dolomite are weighed and mixed, with a controlled share of crushed waste glass added. Small amounts of other ingredients adjust color or help remove bubbles.","inputs":["silica-sand","soda-ash","limestone","dolomite"]},{"name":"Melt it down","process":"melt","text":"A float furnace is about 9 m wide and 45 m long and holds more than 1,200 tons of glass. The batch is heated to roughly 1,500 °C. The glass is then settled at about 1,200 °C so its density is even all the way through.","inputs":[],"spec":"about 1,500 °C"},{"name":"Float it on molten tin","process":"cast","text":"The glass pours from a ceramic lip onto a tin bath about 3–4 m wide, 50 m long and 6 cm deep. Tin is denser than glass and stays calm at that heat, so the glass floats and levels itself. A nitrogen and hydrogen atmosphere over the bath stops the tin from oxidizing.","inputs":["tin","nitrogen","hydrogen"],"spec":"tin bath 50 m long"},{"name":"Pull the ribbon off","process":"roll","text":"As the glass slides along the bath it cools from about 1,100 °C to roughly 600 °C, firm enough to lift onto rollers. The speed of the rollers against the speed of the flow sets the thickness.","inputs":[],"spec":"1,100 °C down to 600 °C"},{"name":"Anneal in the lehr","process":"heat-treat","text":"The ribbon travels through a cooling kiln about 100 m long. Gradual cooling lets the glass settle without strain, so it will not crack when the temperature changes.","inputs":[]},{"name":"Cut at the cold end","process":"cut","text":"Once the sheet exits the kiln, cutting machines score and snap it into panes. Some panes are tempered or laminated afterward, since most specialized glass starts as plain float glass.","inputs":[]},{"name":"Seal two panes together","process":"assemble","text":"For double glazing, two panes are held about 1 cm apart. The gap is sealed permanently and filled with dry air or another dry nonreactive gas, which improves heat and sound insulation and resists fogging.","inputs":[]}],"facts":["Before float glass, large panes were cast as a puddle on an iron table and then ground and polished on both sides.","Sir Alastair Pilkington and Kenneth Bickerstaff developed the tin-bath process between 1953 and 1957, and full-scale profitable sales began in 1960.","In the early 19th century most window glass came from blown cylinders 6 to 8 feet long that were cut open and flattened."],"where":[],"whereNote":null,"sources":[{"title":"Float glass","url":"https://en.wikipedia.org/wiki/Float_glass"},{"title":"Window","url":"https://en.wikipedia.org/wiki/Window"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"windshield","name":"Windshield","kind":"product","category":"machines","title":"How windshields are made","url":"https://assemblyline.org/make/windshield","stations":8,"upstream":62,"downstream":2,"depth":8,"dek":"A windshield is two sheets of glass bent together on one mold, with a plastic layer baked between them.","answer":"A windshield is two curved sheets of glass bonded around a thin plastic layer. Flat glass is cut into outlines and the edges are ground. Both sheets are heated and sagged together over a mold so they share a curve. The sandwich is pressed and baked under pressure in an autoclave, so the layers cannot separate.","aka":["windscreen","laminated safety glass","car windshield"],"inputs":["window-glass","ink","pvb","adhesive"],"uses":["car","electric-car"],"grounds":["silica-sand","limestone","dolomite","water","rock-salt","trona","tin-ore","air","natural-gas","soybeans","rapeseed","clay","crude-oil","titanium-ore","iron-ore","sulfur","corn","sugarcane","coal","sugar-beet"],"upstreamSlugs":["window-glass","ink","pvb","adhesive","silica-sand","soda-ash","limestone","dolomite","tin","nitrogen","hydrogen","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","water","ethanol","polyvinyl-alcohol","propylene","plasticizer","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","rock-salt","ammonia","carbon-dioxide","lime","trona","tin-ore","coke","air","natural-gas","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","crude-oil","titanium-ore","chlorine","oxygen","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","ethylene","methanol","caustic-soda","naphtha","acetone","nitric-acid","coal","benzene","molasses","toluene","sugar-beet"],"downstreamSlugs":["car","electric-car"],"steps":[{"name":"Cut glass to outline","process":"cut","text":"Flat sheets of float glass are scored and snapped into the rough outline of a windshield. Two matching blanks are cut for each one.","inputs":["window-glass"]},{"name":"Grind the edges smooth","process":"grind","text":"Abrasive wheels round the cut edges so the blanks will not chip and can sit exactly together.","inputs":[]},{"name":"Print the black border","process":"print","text":"A ceramic-based black band is printed around the edge. It hides the glue line and shields the adhesive from sunlight, and it fades into the clear glass in a pattern of dots to ease thermal stress.","inputs":["ink"]},{"name":"Sag two sheets together","process":"heat-treat","text":"The two blanks lie stacked on a curved frame as they pass through a furnace. They soften and slump together into the same curve, so they fit each other exactly.","inputs":[]},{"name":"Sandwich in the plastic layer","process":"laminate","text":"The sheets are separated, a thin film of polyvinyl butyral plastic is laid between them, and they are put back together. The film, which is clear and tough, holds the glass together if it breaks.","inputs":["pvb"]},{"name":"Roll out the air","process":"press","text":"Rollers or vacuum bags squeeze air pockets out of the sandwich. The assembly is heated lightly so that the film starts to bond.","inputs":[]},{"name":"Bake it in an autoclave","process":"heat-treat","text":"Heat and high pressure in an autoclave finish the bond. The glass and film then behave as one piece.","inputs":[]},{"name":"Glue it into the opening","process":"weld","text":"At the car plant a bead of urethane adhesive is laid around the frame and the glass is pressed in. A bonded windshield adds rigidity to the body.","inputs":["adhesive"]}],"facts":["The plastic layer in laminated glass can absorb nearly all of the sun's UV-B light, and most UV-A as well.","A car's laminated glass panel is around 6.5 mm thick, and airplane glass is about three times thicker.","A broken windshield cracks in a spider-web pattern instead of dropping sharp shards."],"where":[],"whereNote":null,"sources":[{"title":"Windshield","url":"https://en.wikipedia.org/wiki/Windshield"},{"title":"Laminated glass","url":"https://en.wikipedia.org/wiki/Laminated_glass"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wine","name":"Wine","kind":"product","category":"drink","title":"How wine is made","url":"https://assemblyline.org/make/wine","stations":8,"upstream":46,"downstream":1,"depth":6,"dek":"Wine needs no added sugar or yeast in principle. Grapes arrive carrying both, and the yeast is already on the skins.","answer":"Wine is fermented grape juice. Grapes are picked, crushed and fermented by yeast, which turns their sugar into alcohol and carbon dioxide. Red wine ferments with the skins, which give color and tannin, while white wine is pressed first. The wine is then aged in tank or oak, clarified, filtered, lightly sulfited and bottled.","aka":["red wine","white wine","vinification"],"inputs":["grapes","yeast","wine-barrel","gelatin","glass-bottle"],"uses":["champagne"],"grounds":["grapes","water","timber","pigs","cattle-hide","silica-sand","limestone","sugarcane","sugar-beet","rock-salt","trona","iron-ore","air","dolomite","manganese-ore","natural-gas","corn","coal","quartz","crude-oil","sulfur"],"upstreamSlugs":["grapes","yeast","wine-barrel","gelatin","glass-bottle","water","molasses","timber","steel","pigs","cattle-hide","lime","silica-sand","soda-ash","limestone","polyethylene","sugarcane","sugar-beet","pig-iron","magnesium","steel-scrap","oxygen","manganese","argon","rock-salt","ammonia","carbon-dioxide","trona","ethylene","iron-ore","coke","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","natural-gas","corn","naphtha","coal","quartz","charcoal","crude-oil","sulfur","hydrogen"],"downstreamSlugs":["champagne"],"steps":[{"name":"Pick at the right sugar","process":"harvest","text":"The winemaker decides when to pick using measurements of sugar, acid and pH, as well as taste. Grapes are harvested by hand or by machine.","inputs":["grapes"]},{"name":"Remove stems and crush","process":"crush","text":"Machines strip the berries off their stems and gently split the skins. For white wine the whole bunches may go straight to the press instead.","inputs":[]},{"name":"Let yeast ferment","process":"ferment","text":"Yeast, either wild from the skins or a cultured strain, eats the sugar and gives off alcohol and carbon dioxide. Reds ferment warm, at about 22 to 25 °C, and whites cooler. Every gram of sugar gives about half a gram of alcohol.","inputs":["yeast"],"spec":"one to two weeks"},{"name":"Press the skins","process":"press","text":"For reds, the free-run wine is drained and the leftover skins are pressed to squeeze out the rest. For whites the pressing comes first. Presses ramp up gradually to about 2 bar.","inputs":[]},{"name":"Soften with a second ferment","process":"ferment","text":"Bacteria convert sharp malic acid into milder lactic acid in a malolactic fermentation. Most reds go through it completely, as do rich whites like barrel-fermented chardonnay.","inputs":[]},{"name":"Age in tank or oak","process":"dry","text":"Wine rests for months in steel tanks or oak barrels under an airlock. Fine particles settle, and oak adds aroma and tannin. Cold storage drops out tartrate crystals.","inputs":["wine-barrel"],"spec":"three to six months or more"},{"name":"Fine and filter","process":"separate","text":"Fining agents such as gelatin, egg white or clay bind to tannins and cloudy particles and sink out. The wine is racked off the sediment and filtered.","inputs":["gelatin"]},{"name":"Add sulfite and bottle","process":"fill","text":"A small dose of sulfur dioxide acts as an antioxidant and antimicrobial. The wine is bottled and sealed.","inputs":["glass-bottle"]}],"facts":["Evidence suggests the earliest wine production took place in Georgia and Iran around 6000 to 5000 B.C.","Only about 10% of all red and 5% of white wine will taste better after five years than after one year.","Gelatin is the most commonly used fining agent for removing tannin from wine."],"where":[],"whereNote":null,"sources":[{"title":"Winemaking","url":"https://en.wikipedia.org/wiki/Winemaking"},{"title":"Wine","url":"https://en.wikipedia.org/wiki/Wine"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"cork-stopper","name":"Wine cork","kind":"product","category":"wood-paper","title":"How wine corks are made","url":"https://assemblyline.org/make/cork-stopper","stations":8,"upstream":21,"downstream":1,"depth":5,"dek":"A cork tree can be stripped about every nine years, and the bark grows back each time.","answer":"Cork planks are stripped by hand from the bark of living oak trees, rested outdoors for months, and boiled for an hour. They are trimmed, cut into strips, and stoppers are punched out as cylinders. The corks are polished, scanned, washed, branded and coated with paraffin or silicone so they slide in and out of the bottle.","aka":["cork","wine stopper","natural cork"],"inputs":["cork-bark","paraffin-wax","silicone"],"uses":["champagne"],"grounds":["cork-bark","crude-oil","water","silica-sand","natural-gas","quartz","coal","timber","rock-salt","sulfur","air"],"upstreamSlugs":["cork-bark","paraffin-wax","silicone","crude-oil","hydrogen","silicon","methanol","hydrochloric-acid","water","silica-sand","natural-gas","quartz","coke","coal","charcoal","timber","chlorine","rock-salt","sulfuric-acid","sulfur","air"],"downstreamSlugs":["champagne"],"steps":[{"name":"Rest the planks outdoors","process":"dry","text":"Planks stripped from the forest are stacked outside for months to even out their moisture. Good processors keep them off bare earth to avoid contamination.","inputs":["cork-bark"],"spec":"at least six months"},{"name":"Boil the planks","process":"cook","text":"The planks go into stainless steel tanks of hot water for an hour. That cleans them and softens them. They come out flatter and about a fifth bigger.","inputs":[],"spec":"1 hour, 20% expansion"},{"name":"Trim and grade","process":"inspect","text":"Edges are trimmed. Each plank is graded by thickness, porosity and appearance. The best go for natural stoppers, and the rest for other cork products.","inputs":[]},{"name":"Punch out the cylinders","process":"stamp","text":"The planks are cut into strips, and a tube punch cuts a cylinder from each strip. Top-grade corks are punched by skilled workers by hand. What remains can be ground into granules for glued technical corks.","inputs":[]},{"name":"Polish to size","process":"grind","text":"The cylinders are ground to exact dimensions and a smooth, even surface.","inputs":[]},{"name":"Scan and sort","process":"inspect","text":"Cameras sort each stopper by its look, and X-rays check for hidden flaws and density. Blasts of air push each cork into the right grade bin.","inputs":[]},{"name":"Wash and brand","process":"wash","text":"Corks are washed to clean and whiten them, then branded with heat, ink or laser.","inputs":[]},{"name":"Coat for easy sliding","process":"coat","text":"A thin coat of paraffin or silicone helps the stopper go into the bottle and come out again.","inputs":["paraffin-wax","silicone"]}],"facts":["A cork oak is stripped for the first time after about 25 years, but that first bark is not good enough for wine stoppers.","A cork oak can live about 200 years, giving up its bark again and again.","The harvest year is painted as a number on the trunk, so each tree is not stripped before its time."],"where":[],"whereNote":null,"sources":[{"title":"Raw Material and Industrial Process From bark to bottle","url":"https://amorimcork.com/en/natural-cork/raw-material-and-production-process"},{"title":"How cork is made: an illustrated guide","url":"https://wineanorak.com/corks/howcorkismade.htm"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"grapes","name":"Wine grapes","kind":"raw","category":"farm","title":"How wine grapes are grown and harvested","url":"https://assemblyline.org/make/grapes","stations":5,"upstream":0,"downstream":12,"depth":0,"dek":"A picked grape never gets any sweeter, so a vineyard cannot fix a bad harvest date later.","answer":"A grapevine runs on a yearly cycle. Growers prune it while it rests, then watch buds break in spring, flowers set into berries, and fruit soften and change color at véraison. Many vineyards net the crop against birds. Picking, by hand or machine, is timed to sugar, acid and pH, because sweetening stops the moment a cluster leaves the vine.","aka":["vineyard","wine grape harvest","viticulture","grape picking","winegrowing"],"inputs":[],"uses":["vinegar","wine","champagne","cognac","port-wine","prosecco"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["vinegar","wine","champagne","cognac","port-wine","prosecco","mayonnaise","ketchup","mustard","hot-sauce","salsa","pickles"],"steps":[{"name":"Prune the dormant vines","process":"grow","text":"In late winter or early spring, once the worst cold has passed, growers cut back last season's wood. How much they take off sets both the leaf growth and the size of the crop for the coming year.","inputs":[]},{"name":"Wait out budbreak and bloom","process":"grow","text":"Buds swell in early spring and show their first green leaves. Several weeks later shoots can add an inch or more a day, flowers open, and tiny green berries set. Fruit set is when growers can first gauge the size of the year's crop.","inputs":[]},{"name":"Manage canopy and crop load","process":"grow","text":"Through the summer the viticulturist handles pests, fertilizer, irrigation and the leaf canopy. Some growers also cut away immature bunches in a green harvest, so the vine puts its energy into the clusters that stay.","inputs":[]},{"name":"Net the fruit at véraison","process":"grow","text":"Berries soften. Dark varieties move from green to red, purple or black, while white ones turn translucent, and sugar starts to build. Around now many vineyards hang netting to keep birds off the fruit.","inputs":[]},{"name":"Pick by hand or machine","process":"harvest","text":"Readiness is judged on acidity, pH and sugar, and sometimes on the weather and when a crew can come. Clusters come off by hand or machine, then get processed on site, carried to a winery buying the fruit, or moved into cold storage.","inputs":[]}],"facts":["The oldest known winery, in the Areni-1 cave in Armenia, dates to about 4100 BC.","In its fastest stretch of growth, a grapevine shoot can gain an inch or more in a day.","A healthy, vigorous vine left with all its bunches can give dilute, unripe grapes."],"where":[],"whereNote":null,"sources":[{"title":"Viticulture","url":"https://en.wikipedia.org/wiki/Viticulture"},{"title":"Growing Cycle of a Grapevine, Iowa Wine Growers Association","url":"https://iowawinegrowers.org/lifecycle-of-a-grapevine"},{"title":"The Lifecycle of a Grapevine, Missouri Wines","url":"https://missouriwine.org/node/27206"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wire-rope","name":"Wire rope","kind":"product","category":"metals","title":"How wire rope is made","url":"https://assemblyline.org/make/wire-rope","stations":6,"upstream":26,"downstream":4,"depth":6,"dek":"A crane cable is a hundred or so thin wires twisted into strands, and the strands twisted again around a core.","answer":"Wire rope is made by twisting steel wires into a helix to form a strand, then laying several strands around a central core in a machine called a strander. The wires are high-carbon steel drawn to great strength. A core of fiber or steel carries lubricant, and finished ropes get loops, thimbles or clips.","aka":["steel cable","wire cable","hoist rope"],"inputs":["steel-wire"],"uses":["elevator","suspension-bridge-cable","sailboat"],"grounds":["iron-ore","limestone","air","dolomite","water","manganese-ore","natural-gas","coal","quartz","timber","crude-oil","sulfur"],"upstreamSlugs":["steel-wire","steel","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","iron-ore","coke","limestone","air","dolomite","silicon","propane","water","manganese-ore","sulfuric-acid","natural-gas","coal","quartz","charcoal","timber","crude-oil","sulfur"],"downstreamSlugs":["elevator","suspension-bridge-cable","sailboat","skyscraper"],"steps":[{"name":"Draw high-carbon wire","process":"draw","text":"Rope wires are plain carbon steel with 0.4 to 0.95 percent carbon, drawn very hard so each thin wire is strong. Rope that runs over small pulleys needs wire that bends again and again without cracking.","inputs":["steel-wire"]},{"name":"Spin wires into strands","process":"assemble","text":"Wires are fed from reels through barrels and twisted around a center wire into a helix, layer upon layer. In a parallel-lay strand, each outer wire rests in the groove between two inner wires, so they touch along a line instead of crossing in points.","inputs":[]},{"name":"Choose and fit the core","process":"assemble","text":"The center can be sisal or synthetic fiber, one strand of steel, or a complete small wire rope of its own. Fiber is the most flexible. A steel core resists crushing and lasts best in harsh conditions.","inputs":[]},{"name":"Lay strands round the core","process":"assemble","text":"A strander winds several strands around the core in a helix. The outer strands go in the opposite direction to the wires inside them, which helps the rope resist twisting under load.","inputs":[]},{"name":"Soak in lubricant","process":"coat","text":"The wires slide against one another each time the rope bends, so it is lubricated inside. A natural fiber core can soak up to 15 percent of its own weight in lubricant and feeds it to the wires from within.","inputs":[]},{"name":"Terminate the ends","process":"assemble","text":"Ends are finished with a spliced eye or a loop held by U-bolt clips. A thimble inside the loop stops it bending too sharply and pinching the wires.","inputs":[]}],"facts":["Modern wire rope was invented by the German mining engineer Wilhelm Albert between 1831 and 1834, for mines in the Harz Mountains.","Albert's first rope had three strands of four wires each.","A wire rope can have broken wires and keep working, since the neighbors pick up the load, unlike a chain, where one bad link ends it."],"where":[],"whereNote":null,"sources":[{"title":"Wire rope","url":"https://en.wikipedia.org/wiki/Wire_rope"},{"title":"Wire drawing","url":"https://en.wikipedia.org/wiki/Wire_drawing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wireless-earbuds","name":"Wireless earbuds","kind":"product","category":"electronics","title":"How wireless earbuds are made","url":"https://assemblyline.org/make/wireless-earbuds","stations":9,"upstream":116,"downstream":0,"depth":10,"dek":"Before boxing, a pair is flashed with firmware, paired, dropped, soaked and left running on aging racks.","answer":"Shells come first, molded or machined and then sprayed or polished. Tiny drivers and microphones are built and tested in acoustic chambers, while surface-mount lines load the circuit boards. Workers fit board, battery and driver into each shell, seal it by glue or ultrasonic welding, build the charging case, pair left to right, load firmware and run the set through stress tests.","aka":["true wireless earbuds","bluetooth earbuds","earphones"],"inputs":["polycarbonate","abs-plastic","copper-wire","neodymium-magnet","polyester","printed-circuit-board","microchip","solder","lithium-ion-cell","adhesive","cardboard-box"],"uses":[],"grounds":["air","rare-earth-ore","water","crude-oil","rock-salt","natural-gas","iron-ore","sulfur","copper-ore","nickel-ore","zinc-ore","silica-sand","limestone","quartz","tin-ore","coal","gold-ore","lead-ore","silver-ore","lithium-brine","spodumene","cobalt-ore","manganese-ore","titanium-ore","trona","bauxite","dolomite","timber","soybeans","rapeseed","clay","corn","sugarcane","sugar-beet"],"upstreamSlugs":["polycarbonate","abs-plastic","copper-wire","neodymium-magnet","polyester","printed-circuit-board","microchip","solder","lithium-ion-cell","adhesive","cardboard-box","phenol","propylene","acetone","caustic-soda","chlorine","naphtha","ammonia","air","benzene","ethylene","styrene","pigment","copper","rare-earth-ore","nickel","zinc","pet-plastic","fiberglass","epoxy","photoresist","silicon-wafer","oxygen","tin","aluminum","gold","lead","silver","lithium-carbonate","cobalt","manganese","synthetic-graphite","polyethylene","steel","acrylic","polyurethane","paraffin-wax","water","cardboard","ink","crude-oil","rock-salt","sulfuric-acid","hydrogen","natural-gas","toluene","iron-ore","titanium-dioxide","carbon-black","sulfur","copper-ore","nickel-ore","zinc-ore","p-xylene","ethylene-glycol","silica-sand","limestone","soda-ash","phenolic-resin","polysilicon","quartz","argon","tin-ore","coke","coal","petroleum-coke","alumina","gold-ore","lime","lead-ore","silver-ore","lithium-brine","spodumene","cobalt-ore","manganese-ore","pig-iron","magnesium","steel-scrap","methanol","nitric-acid","wood-pulp","vegetable-oil","ethanol","titanium-ore","carbon-dioxide","trona","formaldehyde","silicon","hydrochloric-acid","trichlorosilane","nitrogen","bauxite","dolomite","propane","timber","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","corn","sugarcane","yeast","charcoal","molasses","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Mold and finish shells","process":"mold","inputs":["polycarbonate","abs-plastic"],"text":"Shells for the buds and the charging case are injection molded or CNC machined, then sprayed, plated or polished. Burrs and poor fit found here would spoil the seal later."},{"name":"Build drivers and microphones","process":"assemble","inputs":["copper-wire","neodymium-magnet","polyester"],"text":"Micro-speakers, microphones and acoustic tubes are made on their own lines. Each goes through an acoustic test chamber to catch distortion, silence or low sensitivity."},{"name":"Populate the board","process":"assemble","inputs":["printed-circuit-board","microchip","solder"],"text":"Surface-mount machines place the parts and a reflow oven fixes them. Optical inspection and in-circuit testers then look for short joints and missing components."},{"name":"Pack the battery","process":"assemble","inputs":["lithium-ion-cell"],"text":"A lithium-ion cell gets a protection module by spot welding and is sealed into a pack, then charged and discharged to prove its capacity. At one plant in Hyderabad, workers solder the tiny batteries to the boards by hand."},{"name":"Close the shell","process":"weld","inputs":["adhesive"],"text":"Board, battery, speaker, microphone and antenna go in the shell. Dispensing machines, ultrasonic welders or small screws then secure and seal it, because a poor seal hurts both sound and water resistance."},{"name":"Build the charging case","process":"assemble","inputs":["lithium-ion-cell","abs-plastic"],"text":"The case gets its own circuit board, battery, charging contacts and a Hall switch, all fixed into the shell. Technicians check the circuitry and how the battery is connected."},{"name":"Pair and flash firmware","process":"inspect","inputs":[],"text":"Firmware is loaded with flashing jigs, and left and right units are paired to each other and to the case. Testers then check Bluetooth, playback, touch control, noise cancellation and charging."},{"name":"Stress and age samples","process":"inspect","inputs":[],"text":"Units face electrical safety checks, water and dust chambers, drop machines and swings of heat and humidity. Aging racks keep them running for long periods to mimic real use."},{"name":"Clean and box","process":"package","inputs":["cardboard-box"],"text":"Inspectors look for scratches and color differences. The set is cleaned and packed into a color box with its manual and charging cable, and units that failed earlier are reworked or discarded."}],"facts":["At Mivi's factory in Hyderabad, workers solder the tiny earbud batteries onto circuit boards by hand.","French engineer Ernest Mercadier patented in-ear headphones in 1891.","Bluetooth is named after Harald Bluetooth, a 10th-century Danish king who united the Danish tribes."],"where":[],"whereNote":null,"sources":[{"title":"True Wireless Earbuds Inspection and Quality Control: production process","url":"https://www.v-trust.com/fr/industries/electrical-electronic-product/true-wireless-earbuds-quality-control"},{"title":"Inside Mivi's Factory: How TWS Earbuds Like the SuperPods Come to Life","url":"https://www.exhibit.tech/tech-features/inside-mivis-factory-how-tws-earbuds-like-the-superpods-come-to-life/"},{"title":"Headphones","url":"https://en.wikipedia.org/wiki/Headphones"},{"title":"Bluetooth","url":"https://en.wikipedia.org/wiki/Bluetooth"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wood-pellets","name":"Wood pellets","kind":"product","category":"chemicals","title":"How wood pellets are made","url":"https://assemblyline.org/make/wood-pellets","stations":5,"upstream":1,"downstream":0,"depth":1,"dek":"A wood pellet sinks in water, because the press packs sawdust denser than water itself.","answer":"Wood pellets are made from sawdust and other wood-milling waste. The material is dried, ground to a uniform dough-like mass in a hammer mill, and squeezed through a die with holes about 6 millimeters wide. The heat and pressure make the wood's own lignin act as glue, and the rods are cooled and bagged.","aka":["pellet fuel","biomass pellets","wood fuel pellets"],"inputs":["timber"],"uses":[],"grounds":["timber"],"upstreamSlugs":["timber"],"downstreamSlugs":[],"steps":[{"name":"Gather the sawdust","process":"separate","text":"Pellet mills use sawdust and waste from lumber mills, furniture plants and construction. Tree tops and shells are also used.","inputs":["timber"]},{"name":"Dry it out","process":"dry","text":"Wet feedstock is dried so that pellets leave with a moisture content below 10 percent. Dry pellets burn at very high efficiency.","inputs":[]},{"name":"Hammer it uniform","process":"crush","text":"A hammer mill breaks the material into a uniform, dough-like mass. Even size makes the press work smoothly.","inputs":[]},{"name":"Squeeze through a die","process":"extrude","text":"A press forces the mass through a die with holes of about 6 millimeters. High pressure heats the wood, softening its lignin so the particles bind.","inputs":[],"spec":"6 mm die holes"},{"name":"Cool and bag the rods","process":"package","text":"Hot pellets are cooled so the lignin hardens, then screened and bagged or blown into bulk trucks.","inputs":[]}],"facts":["Pellets meeting European norms are denser than 1 ton per cubic meter, so they sink in water.","Drying, pelletizing and transporting pellets takes less than 11 percent of the energy the pellets contain, if the wood waste is pre-dried.","High-efficiency pellet stoves and boilers reach combustion efficiencies of over 85 percent."],"where":[],"whereNote":null,"sources":[{"title":"Wood pellet","url":"https://en.wikipedia.org/wiki/Wood_pellet"},{"title":"Charcoal","url":"https://en.wikipedia.org/wiki/Charcoal"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wood-pulp","name":"Wood pulp","kind":"material","category":"wood-paper","title":"How wood pulp is made","url":"https://assemblyline.org/make/wood-pulp","stations":6,"upstream":11,"downstream":86,"depth":3,"dek":"A pulp mill burns the leftover wood goo it cooks out of the logs, and runs on the energy.","answer":"Wood pulp is wood with its glue removed. Logs are debarked and chipped, then cooked in a pressure vessel with a hot, harsh alkaline liquid that dissolves the lignin holding the fibers together. The loose fibers are washed, usually bleached, and dried into sheets. The spent cooking liquid is burned to recover the chemicals.","aka":["kraft pulp","paper pulp","cellulose pulp"],"inputs":["timber","caustic-soda","water","lime","oxygen","hydrogen-peroxide"],"uses":["nail-polish","kitchen-sponge","sanitary-pad","cellulose-acetate","paper","cardboard","toilet-paper","facial-tissue","rayon","diaper"],"grounds":["timber","water","rock-salt","limestone","air","natural-gas"],"upstreamSlugs":["timber","caustic-soda","water","lime","oxygen","hydrogen-peroxide","rock-salt","limestone","air","hydrogen","natural-gas"],"downstreamSlugs":["nail-polish","kitchen-sponge","sanitary-pad","cellulose-acetate","paper","cardboard","toilet-paper","facial-tissue","rayon","diaper","sunglasses","dice","shoelace","eyeglass-frame","soap","adhesive-bandage","aa-battery","vacuum-cleaner","drywall","popcorn","crayon","fireworks","plastic-straw","paper-straw","paper-cup","paper-bag","pizza-box","egg-carton","wallpaper","laminate-floor","board-game","jigsaw-puzzle","tampon","cotton-swab","loudspeaker","vinyl-record","compact-disc","inkjet-printer","newspaper","book","envelope","sticky-notes","playing-cards","toothbrush","duct-tape","plastic-wrap","clear-tape","trading-cards","cake-mix","soda","energy-drink","hair-dye","cardboard-box","match","leather-shoe","candy-cane","toothpaste","deodorant","detergent","plastic-bag","nitrile-glove","washing-machine","electric-kettle","paperclip","donut","corn-flakes","cotton-candy","rubiks-cube","candle","salsa","canned-meat","fish-sticks","zip-bag","blender","dishwasher","pillow","mouthwash","cough-syrup","wheelbarrow","light-switch","smoke-detector","wireless-earbuds","game-console","wifi-router","remote-control","syringe"],"steps":[{"name":"Debark and chip","process":"cut","text":"Logs are stripped of bark, which fuels the mill, and chopped into small uniform chips. Only the heartwood and sapwood carry usable fiber.","inputs":["timber"]},{"name":"Cook the chips","process":"react","text":"Chips go into a digester, a huge pressure cooker, with a hot liquid of sodium hydroxide and sodium sulfide. The liquid dissolves lignin, the natural glue that binds the cellulose fibers, and leaves the fibers intact. About half the weight of the dry wood survives as pulp.","inputs":["caustic-soda","water"],"spec":"170 to 176 °C"},{"name":"Blow out and wash","process":"wash","text":"The cooked chips are blown into a tank at normal pressure, where they fall apart into brown fibers. A chain of washers then rinses the dark liquor out, moving the pulp one way and the wash water the other.","inputs":["water"]},{"name":"Burn the dark liquor","process":"refine","text":"The used cooking liquor is boiled down to a thick syrup and burned in a recovery boiler. The sodium chemicals melt out of the ash and are mixed with lime to rebuild fresh cooking liquid. The same fire raises steam and electricity for the mill.","inputs":["lime"]},{"name":"Bleach to white","process":"dye","text":"For white paper, the brown fibers pass through several bleaching stages. Mills now mostly use chlorine dioxide, oxygen, ozone or hydrogen peroxide instead of chlorine gas. Packaging pulp often skips this step.","inputs":["oxygen","water","hydrogen-peroxide"]},{"name":"Dry into sheets","process":"dry","text":"The clean pulp is pressed and dried into sheets or rolls, and shipped as bales to paper mills. Air-dry pulp keeps about 10 percent moisture so it is easy to break up in water later.","inputs":[],"spec":"about 10% moisture"}],"facts":["The kraft process was patented in Danzig, yet its first mill started in Sweden in 1890, a location attributed to the German paper industry not accepting the new process.","It takes about 24 trees to make a ton of printing and writing paper by the kraft process, and about 12 to make a ton of mechanical pulp.","Tree products make up more than 95 percent of the world's pulp."],"where":[],"whereNote":null,"sources":[{"title":"Pulp (paper)","url":"https://en.wikipedia.org/wiki/Pulp_(paper)"},{"title":"Kraft process","url":"https://en.wikipedia.org/wiki/Kraft_process"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wooden-chair","name":"Wooden chair","kind":"product","category":"wood-paper","title":"How wooden chairs are made","url":"https://assemblyline.org/make/wooden-chair","stations":6,"upstream":70,"downstream":0,"depth":10,"dek":"A wooden chair joined by mortise and tenon can hold together with glue and interlocking wood, and little hardware.","answer":"Wood is dried in a kiln so it stays stable, then cut into legs, rails and slats. Machines cut tenons on the ends of the parts and mortises into the mating parts, and the pieces are glued and clamped together. After the frame is checked for squareness it is sanded, stained or painted, and given a protective coat.","aka":["wood chair","dining chair","rocking chair"],"inputs":["lumber","adhesive","paint"],"uses":[],"grounds":["timber","water","crude-oil","titanium-ore","iron-ore","sulfur","natural-gas","air","rock-salt","coal","tin-ore","corn","sugarcane","soybeans","rapeseed","clay","limestone","dolomite","manganese-ore","quartz","sugar-beet"],"upstreamSlugs":["lumber","adhesive","paint","timber","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","titanium-dioxide","pigment","tin-can","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","titanium-ore","coke","oxygen","iron-ore","carbon-black","sulfur","tinplate","lacquer","ink","naphtha","natural-gas","air","benzene","rock-salt","coal","steel","tin","ethanol","vegetable-oil","phenolic-resin","toluene","pig-iron","magnesium","steel-scrap","lime","manganese","argon","tin-ore","corn","sugarcane","yeast","soybeans","rapeseed","hexane","clay","formaldehyde","limestone","dolomite","silicon","propane","manganese-ore","molasses","quartz","charcoal","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Kiln-dry the lumber","process":"dry","text":"Boards are dried slowly in a kiln to stabilize the wood, so the finished chair will not warp or crack as it gives up moisture.","inputs":["lumber"]},{"name":"Cut the parts to shape","process":"machine","text":"Saws and routers cut legs, rungs, seat boards and back slats. Computer-driven machines can repeat curves and angles exactly.","inputs":[]},{"name":"Cut tenons and mortises","process":"machine","text":"One part gets a peg of wood on its end, the tenon. The mating part gets a rectangular pocket, the mortise. The two have to fit snugly.","inputs":[]},{"name":"Glue and clamp the frame","process":"assemble","text":"Glue goes into each mortise and on each tenon. The frame is clamped until the glue sets, and then checked for square, so it does not rock.","inputs":["adhesive"]},{"name":"Sand it smooth","process":"grind","text":"The assembled chair is sanded to remove tool marks and glue squeeze-out.","inputs":[]},{"name":"Prime and finish","process":"coat","text":"Chairs are stained or painted and given protective coats. Outdoor chairs get several coats of exterior-grade finish.","inputs":["paint"]}],"facts":["Chairs have existed since at least the Early Dynastic Period of Egypt, about 3100 BC.","Early Egyptian chairs were much lower than ours, with seats sometimes only 10 inches high."],"where":[],"whereNote":null,"sources":[{"title":"Chair","url":"https://en.wikipedia.org/wiki/Chair"},{"title":"The Making of a Superior Rocking Chair","url":"https://www.frontera.com/the-making-of-a-superior-chair"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"door","name":"Wooden door","kind":"product","category":"wood-paper","title":"How wooden doors are made","url":"https://assemblyline.org/make/door","stations":6,"upstream":37,"downstream":0,"depth":9,"dek":"A wooden panel door has a loose center panel that floats in a groove, so it can swell and shrink without splitting the frame.","answer":"A panel door is a frame of upright stiles and cross rails around one or more flat or raised panels. Boards are planed to size, cut with matching profiles on a shaper, drilled and doweled, then glued and clamped around panels that sit loose in grooves. The finished door is planed to fit, sanded and finished.","aka":["interior door","panel door","timber door"],"inputs":["lumber","adhesive","plywood","lacquer"],"uses":[],"grounds":["timber","water","crude-oil","corn","sugarcane","natural-gas","air","sulfur","rock-salt","sugar-beet","coal"],"upstreamSlugs":["lumber","adhesive","plywood","lacquer","timber","polyethylene","acrylic","epoxy","polyurethane","paraffin-wax","water","ethanol","ethylene","propylene","ammonia","sulfuric-acid","methanol","phenol","acetone","chlorine","caustic-soda","nitric-acid","crude-oil","hydrogen","corn","sugarcane","yeast","naphtha","natural-gas","air","sulfur","benzene","rock-salt","molasses","toluene","sugar-beet","coal"],"downstreamSlugs":[],"steps":[{"name":"Plane the boards","process":"machine","text":"Lumber is jointed and planed to exact thickness and width. The pieces for the frame are the vertical stiles and the horizontal rails.","inputs":["lumber"]},{"name":"Glue up the panels","process":"laminate","text":"Narrow boards are glued edge to edge into wide panels. Panels may instead be made from plywood or MDF, which move far less than solid wood.","inputs":["adhesive","plywood"]},{"name":"Shape the profiles","process":"machine","text":"A shaper cuts a decorative edge along the inner side of each stile and rail. The end of each rail gets the reverse cut, so it fits over the stile like a puzzle piece.","inputs":[]},{"name":"Drill and dowel","process":"machine","text":"Holes are drilled in the ends of the rails and the edges of the stiles, and wooden dowels reinforce the joints.","inputs":[]},{"name":"Clamp the door together","process":"assemble","text":"Glue goes on the joints, the panel drops in, and the whole frame is squeezed in a clamp. The panel is left unglued and a little smaller than its opening.","inputs":["adhesive"]},{"name":"Plane, sand and finish","process":"grind","text":"The edges are planed so the door fits its opening. It is then sanded, finished and inspected before it leaves.","inputs":["lacquer"]}],"facts":["A wide solid wood panel can change width by half an inch with the seasons, which is why the panel floats loose in a groove.","A basic panel door is called a five-piece door: four frame members and one panel.","Cope-and-stick joints are the most common frame joint, while mortise and tenon is the strongest, used on large doors."],"where":[],"whereNote":null,"sources":[{"title":"Frame and panel","url":"https://en.wikipedia.org/wiki/Frame_and_panel"},{"title":"Passage and entry door construction","url":"https://woodweb.com/knowledge_base/Passage_and_entry_door_construction.html"},{"title":"Stile and Rail Doors: Construction, Styles, and Specs","url":"https://gepettomillworks.com/stile-and-rail-doors/"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wooden-spoon","name":"Wooden spoon","kind":"product","category":"wood-paper","title":"How wooden spoons are made","url":"https://assemblyline.org/make/wooden-spoon","stations":5,"upstream":10,"downstream":0,"depth":4,"dek":"People have carved spoons from wood for so long that the word spoon itself once meant a chip of wood.","answer":"A wooden spoon is shaped from a single piece of hardwood, usually beech, maple or birch. Factories kiln-dry the wood, saw it into blanks, and let CNC machines cut the bowl and handle. Hand sanding reaches the tight spots, and coats of food-safe oil seal the grain.","aka":["wood spoon","stirring spoon"],"inputs":["timber","vegetable-oil"],"uses":[],"grounds":["timber","soybeans","rapeseed","water","clay","crude-oil","natural-gas"],"upstreamSlugs":["timber","vegetable-oil","soybeans","rapeseed","hexane","water","clay","crude-oil","hydrogen","natural-gas"],"downstreamSlugs":[],"steps":[{"name":"Dry the hardwood","process":"dry","text":"Hardwood such as beech or maple is kiln-dried to a low moisture content, so the finished spoon will not warp or crack.","inputs":["timber"],"spec":"6 to 8% moisture"},{"name":"Saw the blanks","process":"cut","text":"Band saws cut the wood into standard blanks, with the grain running along the handle for strength.","inputs":[]},{"name":"Carve bowl and handle","process":"machine","text":"CNC machines cut the bowl and the handle profile from each blank, so every spoon in a run matches. Craft makers do this with an axe, knife and gouge.","inputs":[]},{"name":"Sand it smooth","process":"grind","text":"Machines and hand sanding remove tool marks in stages of finer grit. Wetting the spoon raises the grain, so it is dried and sanded again.","inputs":[]},{"name":"Soak in oil","process":"coat","text":"Oil sinks into the grain and protects the wood from absorbing liquids. Drying oils such as walnut, flax and hempseed polymerize and make a durable finish, but ordinary cooking oils can go rancid.","inputs":["vegetable-oil"]}],"facts":["Wooden spoons were in use among the Iron Age Celts of Britain, and the Romans and Vikings made them too.","Unlike metal spoons, wooden ones do not scratch non-stick pans.","Wooden spoons soak up strong smells, such as onion and garlic."],"where":[],"whereNote":null,"sources":[{"title":"Wooden spoon","url":"https://en.wikipedia.org/wiki/Wooden_spoon"},{"title":"How Are Wooden Spoons Manufactured: From Raw Wood to Finished Utensil","url":"https://qlycheecrafts.com/blog/how-are-wooden-spoons-manufactured/"},{"title":"How Wooden Spoons Are Made","url":"https://ecosall.com/how-wooden-spoons-are-made/"},{"title":"Spoon","url":"https://en.wikipedia.org/wiki/Spoon"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"blanket","name":"Wool blanket","kind":"product","category":"textiles","title":"How wool blankets are made","url":"https://assemblyline.org/make/blanket","stations":5,"upstream":22,"downstream":0,"depth":8,"dek":"The word blanket comes from the French word for white, which named a thick, napped, undyed wool cloth.","answer":"A wool blanket starts with fibers that are carded, spun and woven on a wide loom. The cloth is then milled, a wash with warm water and friction that tightens the weave and shrinks it to size. It is dried and raised by a brushing machine into a soft nap, cut into pieces, and bound with satin or whipstitching.","aka":["woolen blanket","wool throw","bed blanket"],"inputs":["fleece","wool-yarn","thread"],"uses":[],"grounds":["fleece","water","natural-gas","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["fleece","wool-yarn","thread","water","polyester","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","oxygen","carbon-dioxide","crude-oil","hydrogen","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Card and spin the wool","process":"spin","text":"Graded wool, sometimes dyed in the fleece first, goes through a carding machine that mixes the fibers and readies them for spinning. Spinning twists the fibers into a bulky yarn.","inputs":["fleece"]},{"name":"Weave a wide cloth","process":"weave","text":"A wide loom interlaces the yarn into a heavy cloth. A single blanket can need 1,300 warp threads, and the loom is programmed for the yarn and pattern.","inputs":["wool-yarn"]},{"name":"Mill the cloth","process":"knead","text":"The cloth is wound around large cylinders in warm water. Friction locks the fibers closer together, the weave tightens, and the fabric shrinks to its actual size.","inputs":[]},{"name":"Dry and raise the nap","process":"machine","text":"The blanket is dried, then a raising machine brushes the surface and pulls up tiny fiber ends. The raised nap traps warm air and gives the cloth its soft feel.","inputs":[]},{"name":"Cut and bind the edges","process":"sew","text":"The cloth is cut into individual pieces, and the raw edges are finished with satin binding, whipstitching or a fringe. A care label is sewn on before folding and packing.","inputs":["thread"]}],"facts":["The word blanket comes from blanke, the Old French word for white, which named a heavy, napped, undyed wool weave.","Dyed fleece can be blended like paint before spinning, which gives a mottled yarn called melange."],"where":[],"whereNote":null,"sources":[{"title":"Blanket","url":"https://en.wikipedia.org/wiki/Blanket"},{"title":"Wool","url":"https://en.wikipedia.org/wiki/Wool"},{"title":"Manufacturing process of blankets and throws (Creswick Woollen Mills)","url":"https://creswickwool.com/blogs/creswick-history/manufacturing-process-blankets-throws"},{"title":"How is a woven wool blanket made? (British Blanket Company)","url":"https://thebritishblanketcompany.com/blogs/news/how-is-a-woven-wool-blanket-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"fleece","name":"Wool fleece","kind":"raw","category":"farm","title":"How wool is shorn and graded","url":"https://assemblyline.org/make/fleece","stations":3,"upstream":0,"downstream":13,"depth":0,"dek":"A shearer takes the whole fleece off in one piece, and a classer then sorts it into four grades by hand and eye.","answer":"Wool comes from sheep that are shorn once a year, historically in early summer. A shearer removes the entire fleece with clippers. The fleece is then spread on a table, where a wool classer sorts the pieces into fleece, broken fleece, bellies and locks, so that similar wool can be sold together.","aka":["sheep wool","raw wool","greasy wool","sheep shearing"],"inputs":[],"uses":["piano","suit","winter-gloves","felt-hat","blanket","wool-yarn"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["piano","suit","winter-gloves","felt-hat","blanket","wool-yarn","tennis-ball","baseball","silk-tie","socks","sweater","carpet","car"],"steps":[{"name":"Raise the flock","process":"grow","text":"Sheep graze on pasture and grow a fleece that thickens over the year. Merino sheep supply much of the fine apparel wool, and coarser breeds such as Lincoln and Romney grow the longer fibers used in carpets.","inputs":[]},{"name":"Shear the fleece off","process":"harvest","text":"A shearer cuts the woolly fleece off the sheep in one mass. Machine shears, introduced after 1888, cut fewer second passes than blade shears did and shortened the time per sheep.","inputs":[]},{"name":"Sort into four grades","process":"separate","text":"A wool classer groups fleeces by staple length, crimp, handle, color, cleanliness and apparent fineness. Pieces are divided into fleece, which is the bulk and the best, broken fleece, bellies from the underside, and short locks.","inputs":[]}],"facts":["In Australia, shorn wool was once hot-washed on the station, until selling wool in the grease in the 1890s made that obsolete.","Bellies, locks and broken pieces are priced below the main fleece, so classing exists to maximize the return for the farmer."],"where":[{"place":"China, Australia and New Zealand","share":"among the largest producers"}],"whereNote":"2024, by weight of greasy (unscoured) sheep wool. About 1.98 million tonnes were produced worldwide.","sources":[{"title":"Wool","url":"https://en.wikipedia.org/wiki/Wool"},{"title":"Sheep shearing","url":"https://en.wikipedia.org/wiki/Sheep_shearing"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"sweater","name":"Wool sweater","kind":"product","category":"textiles","title":"How wool sweaters are made","url":"https://assemblyline.org/make/sweater","stations":6,"upstream":22,"downstream":0,"depth":8,"dek":"Knitted fabric can stretch up to 500 percent, and a sweater is shaped by the knitting itself.","answer":"A wool sweater is knitted from yarn in flat shaped panels. Machines loop the yarn into a back, front and sleeves, adding or dropping stitches to follow the shape. The pieces are linked together, washed to soften the wool, pressed to size and finished with labels.","aka":["jumper","pullover","jersey","knitwear"],"inputs":["wool-yarn","water","thread"],"uses":[],"grounds":["water","fleece","natural-gas","crude-oil","air","corn","limestone","sugarcane","sugar-beet"],"upstreamSlugs":["wool-yarn","water","thread","fleece","polyester","pet-plastic","p-xylene","ethylene","ethylene-glycol","naphtha","natural-gas","oxygen","carbon-dioxide","crude-oil","hydrogen","air","corn","yeast","limestone","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Dye the yarn","process":"dye","text":"Cones of wool yarn are dyed in the colors the design calls for, because the pattern in a sweater is knit in from colored yarn, not printed on.","inputs":["wool-yarn","water"]},{"name":"Knit the panels","process":"weave","text":"Machines loop the yarn into rows and rows of connected stitches. Knitted fabric is stretchy and soft, and shaping can be built into the fabric by adding or dropping stitches.","inputs":[]},{"name":"Link the pieces","process":"sew","text":"Front, back and sleeves are joined at the shoulders and sides, and the neck is closed with a finished edge.","inputs":["thread"]},{"name":"Wash and relax the wool","process":"wash","text":"The assembled sweater is washed in warm water, which cleans the wool and lets the loops settle. Finishing treatments can reduce felting and make it safe to put in a machine.","inputs":["water"]},{"name":"Press to size","process":"dry","text":"The sweater is dried and pressed or steamed flat to the size on the label.","inputs":[]},{"name":"Tag and fold","process":"package","text":"Labels go on, and the sweaters are folded and bagged for shipping.","inputs":[]}],"facts":["The Oxford English Dictionary dates the word sweater to 1882, when it meant a woolen vest worn in rowing to sweat off weight.","William Lee of Nottinghamshire invented the first stocking frame, an early knitting machine, in 1589."],"where":[],"whereNote":null,"sources":[{"title":"Sweater","url":"https://en.wikipedia.org/wiki/Sweater"},{"title":"Knitting","url":"https://en.wikipedia.org/wiki/Knitting"},{"title":"Wool","url":"https://en.wikipedia.org/wiki/Wool"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wool-yarn","name":"Wool yarn","kind":"material","category":"textiles","title":"How wool yarn is made","url":"https://assemblyline.org/make/wool-yarn","stations":5,"upstream":2,"downstream":9,"depth":1,"dek":"Wool comes off the sheep full of grease, sweat and dirt, and all of it is washed out before anything is spun.","answer":"Wool yarn begins at the shearing shed, where the fleece is cut off whole and sorted by quality. It is scoured in warm water or detergent to strip out grease and dirt, then carded into soft bulky fibers or combed into smooth parallel ones. A spinning frame twists the fibers into yarn.","aka":["worsted yarn","woolen yarn","knitting wool"],"inputs":["fleece","water"],"uses":["tennis-ball","baseball","suit","silk-tie","blanket","socks","sweater","carpet"],"grounds":["fleece","water"],"upstreamSlugs":["fleece","water"],"downstreamSlugs":["tennis-ball","baseball","suit","silk-tie","blanket","socks","sweater","carpet","car"],"steps":[{"name":"Shear the fleece","process":"harvest","text":"A shearer cuts the whole fleece from the sheep in one piece. A wool classer then groups wools of similar grade together to get the best return for each lot.","inputs":["fleece"]},{"name":"Sort by grade","process":"separate","text":"The bulk of the fleece is separated from shorter, broken or dirtier pieces. Merino wool is graded separately, because it is finer than wool from meat breeds.","inputs":[]},{"name":"Scour out the grease","process":"wash","text":"Raw wool, called greasy wool, carries lanolin, dead skin, sweat and plant matter. Scouring washes this out, with baths from simple warm water to detergent and alkali in industrial lines.","inputs":["water"]},{"name":"Card or comb","process":"separate","text":"Carding teases short fibers into a soft, bulky mass for woolen yarn. Combing lines up long fibers and pulls out the short ones, which gives the smooth, strong worsted yarn.","inputs":[]},{"name":"Draw and twist","process":"spin","text":"The wool is drawn out and twisted. Wool's natural crimp, a wave in every fiber, helps the strands cling to each other as the yarn is formed.","inputs":[]}],"facts":["In December 2004, a bale of wool averaging 11.8 microns, then the world's finest, sold in Melbourne for AU$3,000 per kilogram.","Before disinfection and workplace controls, raw wool could carry anthrax spores and give woolsorters a disease."],"where":[{"place":"China","share":"one of the three largest producers"},{"place":"Australia","share":"one of the three largest producers"},{"place":"New Zealand","share":"one of the three largest producers"}],"whereNote":"2024, greasy sheep wool before scouring; the three largest producers by weight, in no ranked order.","sources":[{"title":"Wool","url":"https://en.wikipedia.org/wiki/Wool"},{"title":"Spinning (textiles)","url":"https://en.wikipedia.org/wiki/Spinning_(textiles)"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"wrench","name":"Wrench","kind":"product","category":"hardware","title":"How wrenches are made","url":"https://assemblyline.org/make/wrench","stations":9,"upstream":45,"downstream":0,"depth":6,"dek":"One forging can become more than one wrench size, because the jaws are cut to size afterward.","answer":"Most wrenches begin as rods of 6140 chrome vanadium steel. A hot billet is drop-forged to rough shape, then annealed soft so a broach can size the jaws and a press can stamp the markings. Only then is the wrench hardened, quenched in hot oil and tempered, before polishing and a nickel and chrome plate.","aka":["spanner","open-end wrench"],"inputs":["steel","chromium","vanadium","nickel"],"uses":[],"grounds":["chromite","limestone","air","water","iron-ore","coal","nickel-ore","dolomite","manganese-ore","natural-gas","rock-salt","trona","crude-oil","sulfur","quartz","timber","corn","bauxite","sugarcane","sugar-beet"],"upstreamSlugs":["steel","chromium","vanadium","nickel","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","chromite","coke","soda-ash","limestone","air","water","aluminum","iron-ore","coal","sulfuric-acid","nickel-ore","dolomite","silicon","propane","manganese-ore","natural-gas","rock-salt","ammonia","carbon-dioxide","trona","crude-oil","petroleum-coke","alumina","sulfur","quartz","charcoal","timber","corn","yeast","bauxite","caustic-soda","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Cut and heat the billet","process":"forge","text":"Long rods of 6140 chrome vanadium steel are cut to size and often sand-blasted clean. Each billet then goes into a furnace until it is hot enough to flow.","inputs":["steel","chromium","vanadium"]},{"name":"Drop-forge the shape","process":"forge","text":"A drop hammer pounds the billet into closed dies, giving head and handle in one piece. The result is a rough forging with the right shape but not yet the right dimensions.","inputs":[]},{"name":"Trim the flash","process":"cut","text":"A press punches away the flash that leaked out between the dies and opens the center of ring-shaped heads.","inputs":[]},{"name":"Soften by annealing","process":"heat-treat","text":"The cooled forgings are heated again and slowly brought down. This softens the steel enough to be cut and marked.","inputs":[]},{"name":"Broach the jaws","process":"machine","text":"A broach, a bar whose teeth each stand slightly taller than the last, is pulled through the opening until it reaches the exact size for a bolt head.","inputs":[]},{"name":"Stamp the markings","process":"stamp","text":"A punch press drives in the size, the part number and the maker's name while the metal can still take it.","inputs":[]},{"name":"Harden and temper","process":"heat-treat","text":"The wrench is heated and quenched in hot oil, which slows the cooling and avoids micro cracks. A second gentler heating takes out the brittleness, and a tester checks the hardness.","inputs":[]},{"name":"Polish the surface","process":"grind","text":"Machines or hands polish away the marks of forging. This is the first step that sets how the finished tool looks.","inputs":[]},{"name":"Plate in chrome","process":"coat","text":"In an electroplating bath, a flash of nickel goes on first and a layer of chrome on top. Some wrenches get a black oxide finish instead.","inputs":["nickel","chromium"]}],"facts":["In the United Kingdom, Ireland, Australia and New Zealand the same tool is called a spanner.","In North American English, a spanner is a specialized wrench with pins or tabs for round nuts.","Wrenches are often quenched in hot oil, because cooling the steel too fast can leave micro cracks in it."],"where":[],"whereNote":null,"sources":[{"title":"Wrench","url":"https://en.wikipedia.org/wiki/Wrench"},{"title":"Drop forging","url":"https://en.wikipedia.org/wiki/Drop_forging"},{"title":"Inside the Tool: How Wrenches Are Made","url":"https://shopgraytools.com/blogs/news/inside-the-tool-how-wrenches-are-made"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"yo-yo","name":"Yo-yo","kind":"product","category":"play","title":"How yo-yos are made","url":"https://assemblyline.org/make/yo-yo","stations":8,"upstream":52,"downstream":0,"depth":8,"dek":"One yo-yo patent press-fits its nut after molding, since a brass nut molded in makes rejects impossible to recycle.","answer":"Two routes show up in patents and machine shops. Plastic halves shoot from injection molds, with a threaded nut molded in or pressed into a socket afterward. Metal halves are turned on a CNC lathe from aluminum bar, hollowed out and tapped. Either way, an axle joins the halves, the string loop goes on, and one half screws onto the other.","aka":["yoyo","bandalore"],"inputs":["plastic","steel","aluminum","ball-bearing","thread"],"uses":[],"grounds":["natural-gas","crude-oil","coal","water","iron-ore","limestone","air","dolomite","manganese-ore","bauxite","quartz","timber","sulfur","rock-salt","zinc-ore","corn","sugarcane","sugar-beet"],"upstreamSlugs":["plastic","steel","aluminum","ball-bearing","thread","naphtha","natural-gas","ethylene","propylene","pig-iron","magnesium","steel-scrap","oxygen","lime","manganese","argon","crude-oil","coal","petroleum-coke","alumina","steel-wire","sheet-steel","polyester","water","hydrogen","iron-ore","coke","limestone","air","dolomite","silicon","propane","manganese-ore","sulfuric-acid","bauxite","caustic-soda","zinc","pet-plastic","quartz","charcoal","timber","sulfur","rock-salt","zinc-ore","p-xylene","ethylene-glycol","carbon-dioxide","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Machine the molds","process":"machine","text":"Molds are modeled on a computer and cut from solid metal. Student teams in an MIT manufacturing course mill theirs from aluminum billets, then load them into a 30 ton injection molding machine.","inputs":[]},{"name":"Shoot the plastic halves","process":"mold","text":"Plastic is injected into the closed mold to form each half. A conventional setup places a threaded insert on a core pin first. Yomega's patent molds a hexagonal socket instead, so continuous automated machines can run without anyone loading inserts.","inputs":["plastic"]},{"name":"Press in the nut","process":"assemble","text":"A hexagonal threaded nut is pressed into the socket, guided by a shallow wider recess at its mouth. Its corners stop it turning. Because it goes in later, it can be steel like the axle, which makes stripped threads less likely.","inputs":["steel"]},{"name":"Turn the metal bodies","process":"machine","text":"Metal yo-yos start as blanks sawn from 2.5 inch 6061 aluminum round. In one CNC lathe project, tools turn the outside, drill and tap the center, bore out the inside, then cut the final profile and part it off. A small pip left behind gets filed away.","inputs":["aluminum"]},{"name":"Stick on response pads","process":"assemble","text":"Self-adhesive pads go on the inner face of each metal half, centered as closely as possible. They let the yo-yo grip the string and climb back to the hand.","inputs":[]},{"name":"Seat axle and bearing","process":"assemble","text":"A threaded center shaft screws into one half and a ball bearing presses onto its shoulder. The bearing reduces friction, so a skilled player can keep a yo-yo spinning for minutes, where a fixed axle lasts 10 to 20 seconds.","inputs":["ball-bearing"]},{"name":"Loop on the string","process":"assemble","text":"String made from one twisted length is untwisted slightly at its end to open a loop, which drops over the bearing. It sits loose, so the yo-yo can spin at the bottom of a throw.","inputs":["thread"]},{"name":"Screw the halves together","process":"assemble","text":"The second half threads onto the shaft and closes around the string. Plastic halves often also get a thin cover, which student teams vacuum-form separately.","inputs":[]}],"facts":["Yo-yos were known to ancient Greeks and appear on vase paintings. Examples survive in bronze and fired clay.","By November 1929 Pedro Flores's factories in California employed 600 workers, making 300,000 units a day.","A court case in 1965 decided that yo-yo had become common speech, so Duncan lost exclusive rights to the name."],"where":[],"whereNote":null,"sources":[{"title":"US6494761B1, Yo-yo and method for its manufacture","url":"https://patents.google.com/patent/US6494761"},{"title":"Aluminum Yo-Yo CNC Project, Tormach","url":"https://tormach.com/aluminum-yo-yo"},{"title":"2.008 Design and Manufacturing II, Ilan Moyer, MIT","url":"https://web.mit.edu/imoyer/www/portfolio-phd/2008/index.html"},{"title":"Yo-yo","url":"https://en.wikipedia.org/wiki/Yo-yo"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"yoga-mat","name":"Yoga mat","kind":"product","category":"play","title":"How yoga mats are made","url":"https://assemblyline.org/make/yoga-mat","stations":6,"upstream":22,"downstream":0,"depth":6,"dek":"The first sticky yoga mat was a piece of carpet underlay, cut to towel size by a teacher in Germany.","answer":"A mat's bubbly grip can come from foaming. Two Chinese patents stir PVC paste with plasticizer and a foaming agent, spread it onto a tensioned mesh, then pull it through a hot chamber where it expands. The foamed sheet cools, sets and is cut to the ordered size. Fabric-backed and rubber mats follow other routes, some of them vulcanized instead.","aka":["exercise mat","sticky mat","yoga mats"],"inputs":["pvc","plasticizer"],"uses":[],"grounds":["water","air","natural-gas","rock-salt","iron-ore","sulfur","crude-oil","titanium-ore","coal"],"upstreamSlugs":["pvc","plasticizer","ethylene","chlorine","water","pigment","naphtha","air","propylene","natural-gas","rock-salt","sulfuric-acid","iron-ore","titanium-dioxide","carbon-black","sulfur","crude-oil","hydrogen","titanium-ore","coke","oxygen","coal"],"downstreamSlugs":[],"steps":[{"name":"Blend the paste","process":"mix","text":"PVC paste resin is stirred with a stabilizer and a foaming agent, then plasticizer goes in until it forms an even, spreadable mixture. Raw materials follow a set formula, which differs by maker.","inputs":["pvc","plasticizer"]},{"name":"Tension the mesh","process":"assemble","text":"A mesh cloth is drawn onto a needle rail and pulled tight and flat. It gives the finished foam something to hold onto.","inputs":[]},{"name":"Spread the paste","process":"coat","text":"A blade or brush runs the paste across the moving mesh in a continuous coat. Machine zones are warmed and set before the run begins.","inputs":[]},{"name":"Foam in the chamber","process":"heat-treat","text":"Needle plates carry the coated mesh into a hot chamber. The paste plasticizes and the foaming agent swells it, leaving visible bubble points on the front and a flat back.","inputs":[]},{"name":"Cool and set","process":"chill","text":"The sheet leaves the chamber, gives up its heat gradually, and sets in its final form as it is cooled further.","inputs":[]},{"name":"Cut to order","process":"cut","text":"A cutter frame at the tail of the line is adjusted to the length and size each order calls for, usually near 6 feet by 2 feet.","inputs":[]}],"facts":["Before modern mats, people practiced yoga on bare ground, on kusha grass, or on deer or tiger skin.","A PVC yoga mat may need over 500 years to decompose, and even a natural rubber one 80.","One exercise-mat patent vulcanizes a foam compound under a fabric layer, so the foam squeezes up through the fabric's pores as grip bumps."],"where":[],"whereNote":null,"sources":[{"title":"CN101564584A, Yoga mat manufacturing method","url":"https://patents.google.com/patent/CN101564584A/en"},{"title":"CN102000412B, PVC plastic foam yoga mat and preparation method","url":"https://patents.google.com/patent/CN102000412B/en"},{"title":"US20070071961A1, Exercise mat","url":"https://patents.google.com/patent/US20070071961"},{"title":"Lifecycle of a yoga mat, Yoga Journal","url":"https://www.yogajournal.com/lifestyle/fashion-beauty/yoga-gear/lifecycle-of-a-yoga-mat/?scope=anon"},{"title":"Yoga mat","url":"https://en.wikipedia.org/wiki/Yoga_mat"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"yogurt","name":"Yogurt","kind":"product","category":"food","title":"How yogurt is made","url":"https://assemblyline.org/make/yogurt","stations":6,"upstream":11,"downstream":0,"depth":3,"dek":"Two bacteria that cooperate turn milk into yogurt in as little as 4 hours.","answer":"Milk is standardized, often with added milk powder, then heated hard and cooled to incubation temperature. Two bacteria, Lactobacillus bulgaricus and Streptococcus thermophilus, are mixed in and the milk is held warm for 4 to 12 hours. Acid builds, the proteins set, and the yogurt is cooled, flavored and packed.","aka":["yoghurt","set yogurt","Swiss-style yogurt"],"inputs":["pasteurized-milk","sugar","gelatin"],"uses":[],"grounds":["raw-milk","sugarcane","sugar-beet","water","pigs","cattle-hide","limestone"],"upstreamSlugs":["pasteurized-milk","sugar","gelatin","raw-milk","sugarcane","sugar-beet","water","lime","pigs","cattle-hide","limestone"],"downstreamSlugs":[],"steps":[{"name":"Fortify the milk","process":"mix","text":"Milk is balanced for fat, and dried milk is often added because extra solids make a firmer yogurt. Cow milk is typical, but goat, sheep and camel milk set differently.","inputs":["pasteurized-milk"]},{"name":"Heat it hard","process":"pasteurize","text":"The milk is held hot, well past the heat of normal pasteurization. The heat kills pathogens and unfolds the whey proteins so they bind to the casein and make a thicker, smoother set.","inputs":[]},{"name":"Cool and inoculate","process":"chill","text":"Milk is cooled to a comfortable fermenting temperature and the starter culture is mixed in. The two main bacteria are Lactobacillus delbrueckii bulgaricus and Streptococcus thermophilus, and they help each other grow.","inputs":[]},{"name":"Incubate until it sets","process":"ferment","text":"The milk is held at 30 to 45 °C for 4 to 12 hours. Bacteria turn lactose into lactic acid, the acid curdles the casein, and the milk gels. Higher temperatures work faster but risk a lumpy texture.","inputs":[],"spec":"4 to 12 hours"},{"name":"Stir or leave set","process":"mix","text":"For set-style yogurt, the milk is poured into cups before incubation and sets right in the container. For Swiss-style, the finished gel is stirred smooth in a vat before it is packed.","inputs":[]},{"name":"Flavor and fill cups","process":"fill","text":"Fruit, sweeteners, and sometimes starch, pectin or gelatin are blended in. The yogurt is filled into cups, sealed and chilled quickly to slow the fermentation.","inputs":["sugar","gelatin"]}],"facts":["In 1905 the Bulgarian medical student Stamen Grigorov isolated the bacterium now known as Lactobacillus delbrueckii bulgaricus from soured milk from his home village.","Yogurt with fruit jam at the bottom was patented in 1933 by a dairy in Prague."],"where":[],"whereNote":null,"sources":[{"title":"Yogurt","url":"https://en.wikipedia.org/wiki/Yogurt"},{"title":"Milk","url":"https://en.wikipedia.org/wiki/Milk"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"zinc","name":"Zinc","kind":"material","category":"metals","title":"How zinc is made","url":"https://assemblyline.org/make/zinc","stations":6,"upstream":5,"downstream":143,"depth":2,"dek":"Zinc boils off in a smelting furnace, so the biggest share is dissolved in acid and plated out by electricity instead.","answer":"Zinc is made from sphalerite, a zinc sulfide. The ore is concentrated by flotation, roasted into zinc oxide, and dissolved in sulfuric acid. After the solution is purified with zinc dust, an electric current plates pure zinc onto aluminum sheets, and the metal is melted and cast into ingots.","aka":["spelter","zinc metal"],"inputs":["zinc-ore","air","sulfuric-acid"],"uses":["sunscreen","hearing-aid","aa-battery","sheet-steel","rebar","brass","lead","gold","silver","neodymium-magnet","nail","screw","steel-pipe","coin","zinc-oxide","staple","flute","toy-car","bolt","barbed-wire","chain-link-fence","medal","suspension-bridge-cable"],"grounds":["zinc-ore","air","sulfur","water"],"upstreamSlugs":["zinc-ore","air","sulfuric-acid","sulfur","water"],"downstreamSlugs":["sunscreen","hearing-aid","aa-battery","sheet-steel","rebar","brass","lead","gold","silver","neodymium-magnet","nail","screw","steel-pipe","coin","zinc-oxide","staple","flute","toy-car","bolt","barbed-wire","chain-link-fence","medal","suspension-bridge-cable","electric-motor","transformer","refrigerator","microwave-oven","washing-machine","vacuum-cleaner","safety-pin","padlock","ball-bearing","car","electric-car","airbag","shipping-container","elevator","dishwasher","air-conditioner","ceiling-fan","water-heater","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","concrete","skyscraper","wristwatch","faucet","tire","electric-guitar","trumpet","ballpoint-pen","pencil-eraser","fountain-pen","garden-hose","harmonica","saxophone","guitar-string","key","gas-cylinder","light-switch","power-outlet","leather-belt","handbag","flag","phone-charger","usb-cable","zipper","solder","chess-set","stained-glass","car-battery","sailboat","microchip","led","needle","gold-ring","gold-bar","smoke-detector","solar-cell","mirror","thermos","vinyl-record","headphones","wind-turbine","wireless-earbuds","loudspeaker","microphone","electric-toothbrush","scissors","rubiks-cube","ice-skates","action-figure","suitcase","high-heels","eyeglass-frame","game-console","graphics-card","container-ship","treadmill","foundation-makeup","ferrite","roller-skates","drone","locomotive","blender","subway-train","inkjet-printer","bicycle","motorcycle","skateboard","yo-yo","down-jacket","raincoat","backpack","jeans","pacemaker","printed-circuit-board","led-bulb","solid-state-drive","solar-panel","smartwatch","wifi-router","remote-control","thermometer","credit-card","smartphone","laptop","television","computer-keyboard","computer-mouse","satellite","rocket","digital-camera","e-reader","lcd-screen","pinball-machine","ev-battery","hard-drive","airplane"],"steps":[{"name":"Float the zinc sulfide","process":"separate","text":"Ore is crushed and floated to give a zinc concentrate. About 95 percent of new zinc comes from sulfide deposits, where sphalerite is nearly always mixed with sulfides of copper, lead and iron.","inputs":["zinc-ore"]},{"name":"Roast it to oxide","process":"bake","text":"In a roaster, hot air turns the sulfide into impure zinc oxide called calcine. About 90 percent of the zinc ends up as oxide, and roughly 10 percent reacts with iron to form zinc ferrite. The sulfur dioxide given off is captured and made into sulfuric acid.","inputs":["air"]},{"name":"Leach it in acid","process":"react","text":"The calcine is washed first in a weak acid solution, and then in strong sulfuric acid, to pull out all the zinc. Some of the acid comes from the roaster's own sulfur dioxide.","inputs":["sulfuric-acid"]},{"name":"Purify the solution","process":"refine","text":"Zinc dust and steam knock copper, cadmium, cobalt and nickel out of the liquid. The solution must be very pure, or the cell will make hydrogen gas rather than zinc.","inputs":[]},{"name":"Plate it out electrically","process":"electrolyze","text":"An electric current passes through the solution in a hall of cells, and zinc deposits on aluminum sheets used as cathodes, while oxygen forms at the anodes. The cells stay at 30 to 35 °C, and the sulfuric acid they make is returned to the leach tanks.","inputs":[],"spec":"30 to 35 °C"},{"name":"Melt and cast ingots","process":"cast","text":"Sheets of zinc are stripped from the cathodes, melted and cast into ingots, ready for galvanizing plants and brass makers.","inputs":[]}],"facts":["A zinc plant partly feeds itself: roasting gives off sulfur dioxide that becomes the sulfuric acid which dissolves the roasted ore, and the plating cells make more acid to send back.","Zinc is the fourth most common metal in use, after iron, aluminum and copper.","Over 30 percent of zinc comes from recycling."],"where":[{"place":"China","share":"38% of global zinc output"},{"place":"Australia","share":"one of the main mining areas"},{"place":"Peru","share":"one of the main mining areas"}],"whereNote":"2014, share of global zinc output.","sources":[{"title":"Zinc smelting","url":"https://en.wikipedia.org/wiki/Zinc_smelting"},{"title":"Zinc","url":"https://en.wikipedia.org/wiki/Zinc"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"zinc-ore","name":"Zinc ore","kind":"raw","category":"ground","title":"How zinc ore is mined","url":"https://assemblyline.org/make/zinc-ore","stations":4,"upstream":0,"downstream":150,"depth":0,"dek":"Zinc's main ore was named for the Greek word for deceiving, because it looks like galena but yields no lead.","answer":"Zinc ore comes up from open pits or underground workings, mostly as a dark sulfide called sphalerite. Mills crush it, mix it with water and grind it to a slurry, then blow air through flotation cells so the zinc sulfide climbs onto bubbles and leaves as froth. The same mineral also yields small amounts of cadmium, gallium, germanium and indium.","aka":["sphalerite","zinc blende","black-jack"],"inputs":[],"uses":["zinc","silver","gallium","indium","germanium"],"grounds":[],"upstreamSlugs":[],"downstreamSlugs":["zinc","silver","gallium","indium","germanium","sunscreen","hearing-aid","aa-battery","sheet-steel","rebar","brass","lead","gold","neodymium-magnet","nail","screw","steel-pipe","coin","zinc-oxide","staple","flute","toy-car","bolt","barbed-wire","chain-link-fence","medal","suspension-bridge-cable","solar-cell","solder","gold-ring","mirror","trumpet","thermos","saxophone","light-switch","smoke-detector","vinyl-record","led","indium-tin-oxide","optical-fiber","electric-motor","transformer","refrigerator","microwave-oven","washing-machine","vacuum-cleaner","safety-pin","padlock","ball-bearing","car","electric-car","airbag","shipping-container","elevator","dishwasher","air-conditioner","ceiling-fan","water-heater","hinge","saw-blade","shovel","wheelbarrow","fire-extinguisher","brake-pad","concrete","skyscraper","wristwatch","faucet","tire","electric-guitar","ballpoint-pen","pencil-eraser","fountain-pen","garden-hose","harmonica","guitar-string","key","gas-cylinder","power-outlet","leather-belt","handbag","flag","phone-charger","usb-cable","zipper","chess-set","stained-glass","car-battery","sailboat","microchip","needle","gold-bar","headphones","wind-turbine","wireless-earbuds","loudspeaker","microphone","electric-toothbrush","scissors","rubiks-cube","ice-skates","action-figure","suitcase","high-heels","eyeglass-frame","game-console","graphics-card","container-ship","treadmill","foundation-makeup","ferrite","roller-skates","solar-panel","pacemaker","printed-circuit-board","led-bulb","solid-state-drive","drone","smartwatch","wifi-router","inkjet-printer","remote-control","lcd-screen","television","computer-mouse","pinball-machine","e-reader","oled-screen","locomotive","blender","subway-train","bicycle","motorcycle","skateboard","yo-yo","down-jacket","raincoat","backpack","jeans","thermometer","credit-card","smartphone","laptop","computer-keyboard","satellite","rocket","digital-camera","ev-battery","hard-drive","airplane"],"steps":[{"name":"Cut out the sulfide","process":"mine","text":"Zinc ores are taken from open pits and from underground, where cut-and-fill stoping is the most common method. Mount Isa in Australia reaches its ore through a shaft 1,144 m deep and hoists it in skips.","inputs":[]},{"name":"Grind to a slurry","process":"crush","text":"Rock is crushed, mixed with water and milled until sulfide grains come free. Mount Isa's concentrator was built around rod and ball mills, and it added heavy-medium separation to reject waste ahead of them.","inputs":[]},{"name":"Float the sulfide grains","process":"separate","text":"Reagents and air go into flotation cells. Zinc sulfide clings to the bubbles and is skimmed off as froth while waste rock sinks. Sphalerite often travels with lead minerals, so a mixed ore like Mount Isa's gets a lead-silver float and a separate zinc float.","inputs":[]},{"name":"Regrind and clean","process":"grind","text":"Some ore needs another pass. To handle its George Fisher ore, Mount Isa added ISAmills for ultra-fine regrinding, along with better cleaner flotation, to lift recovery and concentrate grade. The finished concentrate goes to a smelter for roasting.","inputs":[]}],"facts":["Sphalerite got its name in 1847 from the Greek word for deceiving, because it is so hard to identify.","Miners called the ore blende, from German words for blind or deceiving, since it looks like galena yet holds no lead.","Alongside zinc, sphalerite also yields cadmium, gallium, germanium and indium."],"where":[],"whereNote":null,"sources":[{"title":"Zinc processing","url":"https://www.britannica.com/technology/zinc-processing"},{"title":"Mount Isa Lead/Zinc Mine","url":"https://www.mining-technology.com/projects/mount_isla_lead/"},{"title":"Sphalerite","url":"https://en.wikipedia.org/wiki/Sphalerite"},{"title":"Zinc","url":"https://en.wikipedia.org/wiki/Zinc"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"zinc-oxide","name":"Zinc oxide","kind":"material","category":"chemicals","title":"How zinc oxide powder is made","url":"https://assemblyline.org/make/zinc-oxide","stations":5,"upstream":6,"downstream":5,"depth":3,"dek":"Zinc oxide forms when zinc vapor meets air and flashes into a bright glow.","answer":"In the French process, metallic zinc is melted in a graphite crucible and vaporized at about 1000 °C. The vapor meets the oxygen in air and burns into a white powder that glows as it forms. The fine particles are carried through a cooling duct and caught in a bag house.","aka":["zinc white","ZnO","French process zinc oxide"],"inputs":["zinc","air"],"uses":["foundation-makeup","ferrite"],"grounds":["air","zinc-ore","sulfur","water"],"upstreamSlugs":["zinc","air","zinc-ore","sulfuric-acid","sulfur","water"],"downstreamSlugs":["foundation-makeup","ferrite","headphones","phone-charger","loudspeaker"],"steps":[{"name":"Melt the zinc metal","process":"melt","text":"Metallic zinc is melted in a graphite crucible. The charge is raised well past the boiling point of zinc.","inputs":["zinc"]},{"name":"Heat it past boiling","process":"melt","text":"The molten zinc is heated further until it vaporizes. Above 907 °C zinc boils, and plants typically run around 1000 °C.","inputs":[]},{"name":"Burn the vapor in air","process":"react","text":"Zinc vapor reacts with oxygen in the air to give zinc oxide. Temperature drops sharply and the reaction gives off a bright luminescence.","inputs":["air"],"spec":"about 1000 °C"},{"name":"Cool and catch the powder","process":"separate","text":"Oxide particles travel into a cooling duct and are collected in a bag house, which works like a huge vacuum-cleaner bag.","inputs":[]},{"name":"Bag the white powder","process":"package","text":"The powder is graded by particle size and packed for rubber makers, paint makers and cosmetics plants.","inputs":[]}],"facts":["Today most zinc oxide goes to the rubber industry.","In the 1970s zinc-oxide-coated paper was the second-largest use of the powder, in photocopying.","Zinc white was accepted as an oil-painting pigment by 1834."],"where":[],"whereNote":null,"sources":[{"title":"Zinc oxide","url":"https://en.wikipedia.org/wiki/Zinc_oxide"},{"title":"Vulcanization","url":"https://en.wikipedia.org/wiki/Vulcanization"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"zip-bag","name":"Zip-top bag","kind":"product","category":"plastics","title":"How zip-top bags are made","url":"https://assemblyline.org/make/zip-bag","stations":6,"upstream":55,"downstream":0,"depth":10,"dek":"On some lines, the zipper of a zip-top bag is extruded in the same pass as the bag itself.","answer":"Polyethylene is melted and blown into a tube of film. In bag lines with an integral zipper, the die lays down two thicker ridges that will become the interlocking zipper halves, and those ridges are cooled harder than the rest. The tube is then sealed across at intervals and cut into individual bags.","aka":["Ziploc bag","resealable bag","ziplock bag","sandwich bag"],"inputs":["polyethylene","cardboard-box"],"uses":[],"grounds":["natural-gas","water","crude-oil","timber","soybeans","rapeseed","clay","air","titanium-ore","iron-ore","sulfur","corn","sugarcane","rock-salt","limestone","coal","sugar-beet"],"upstreamSlugs":["polyethylene","cardboard-box","ethylene","cardboard","ink","adhesive","naphtha","natural-gas","water","wood-pulp","vegetable-oil","phenolic-resin","carbon-black","titanium-dioxide","pigment","ethanol","acrylic","epoxy","polyurethane","paraffin-wax","crude-oil","hydrogen","timber","caustic-soda","lime","oxygen","hydrogen-peroxide","soybeans","rapeseed","hexane","clay","phenol","formaldehyde","air","titanium-ore","chlorine","coke","sulfuric-acid","iron-ore","sulfur","corn","sugarcane","yeast","propylene","ammonia","methanol","acetone","nitric-acid","rock-salt","limestone","benzene","coal","molasses","toluene","sugar-beet"],"downstreamSlugs":[],"steps":[{"name":"Melt the pellets","process":"melt","text":"Polyethylene pellets are heated in an extruder until they flow like thick syrup.","inputs":["polyethylene"]},{"name":"Blow a tube with ridges","process":"blow","text":"The melt exits a ring die and is inflated into a bubble of film. Slots in the die let two thickened ridges form on the inside, one for each half of the zipper.","inputs":[]},{"name":"Chill the ridges first","process":"chill","text":"The thick ridges hold heat longer than the thin film. A jet of cool gas or radiant cooling aimed at them sets their shape before they can sag.","inputs":[]},{"name":"Seal the zipper ends","process":"weld","text":"At the end of each bag the ridges are squashed flat with a heat seal, so the zipper cannot snag or leak at the corner.","inputs":[]},{"name":"Seal the sides and cut","process":"cut","text":"Heated bars weld the flattened film across at each bag length, and a blade parts the bags from one another.","inputs":[]},{"name":"Count and box","process":"package","text":"Finished bags are counted into stacks and packed in cartons.","inputs":["cardboard-box"]}],"facts":["Plastic bags were once too costly to sell to shoppers, until Dow engineers pushed line speed from 30 feet per minute to 300 by 1972.","The companies behind the plastic zipper, Dow among them, obtained over 300 patents for zippers, zipper bags and the machines that make them."],"where":[],"whereNote":null,"sources":[{"title":"Ziploc","url":"https://en.wikipedia.org/wiki/Ziploc"},{"title":"Extrusion system and method for blown film with integral profiles","url":"https://patents.google.com/patent/US11072103"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"},{"slug":"zipper","name":"Zipper","kind":"product","category":"textiles","title":"How zippers are made","url":"https://assemblyline.org/make/zipper","stations":6,"upstream":45,"downstream":6,"depth":8,"dek":"A zipper works because a Y-shaped channel in the slider forces two rows of teeth to mesh as it moves.","answer":"A zipper is a slider running along two rows of interlocking teeth, each row attached to a strip of fabric tape. Factories weave the tape, form the teeth from coiled plastic filament or molded metal or plastic, fasten them on, then add stops and the slider. Coil zippers form the bulk of sales worldwide.","aka":["zip","zip fastener","clasp locker"],"inputs":["polyester","nylon","brass","thread","aluminum"],"uses":["down-jacket","raincoat","handbag","backpack","suitcase","jeans"],"grounds":["water","crude-oil","coal","air","natural-gas","copper-ore","zinc-ore","lead-ore","tin-ore","bauxite","sulfur","rock-salt","limestone","corn","sugarcane","sugar-beet"],"upstreamSlugs":["polyester","nylon","brass","thread","aluminum","pet-plastic","benzene","nitric-acid","ammonia","copper","zinc","lead","tin","water","crude-oil","coal","petroleum-coke","alumina","p-xylene","ethylene","ethylene-glycol","naphtha","hydrogen","toluene","air","natural-gas","copper-ore","oxygen","sulfuric-acid","zinc-ore","lead-ore","coke","tin-ore","bauxite","caustic-soda","lime","carbon-dioxide","sulfur","rock-salt","limestone","corn","yeast","molasses","sugarcane","sugar-beet"],"downstreamSlugs":["down-jacket","raincoat","handbag","backpack","suitcase","jeans"],"steps":[{"name":"Weave the tape","process":"weave","text":"Narrow fabric tape is woven in long ribbons. The tape is what is sewn into the garment, so it needs to be sturdy and to take dye.","inputs":["polyester"]},{"name":"Form the teeth","process":"mold","text":"For coil zippers, a nylon or polyester filament is wound into a spiral. For metal zippers, individual teeth are molded from brass, aluminium or nickel. Plastic-molded zippers use plastic teeth, most often polyacetal resin.","inputs":["nylon","brass"]},{"name":"Fix the teeth to the tape","process":"sew","text":"Coils are stitched along the edge of the tape, and metal or plastic teeth are clamped on at regular spacing. Gideon Sundbäck's design from the early twentieth century packed in ten or eleven teeth per inch, compared with four before.","inputs":["thread"]},{"name":"Dye the tape","process":"dye","text":"Tape and coil are dyed to match the garment. Plastic teeth can be made in any color, and metal teeth can be painted.","inputs":[]},{"name":"Add the stops and slider","process":"assemble","text":"Stops are fitted at the top and bottom to keep the slider on the chain. The slider is threaded on, and its pull tab is attached.","inputs":["aluminum"]},{"name":"Cut to length and pack","process":"cut","text":"Long chains are cut to the lengths ordered, and the zippers are counted and packed.","inputs":[]}],"facts":["Whitcomb L. Judson patented a Shoe-Fastening in 1893 and a clasp-locker design the same year, an early ancestor of the zipper.","The name zipper was first used by the B. F. Goodrich Company in 1923 for its rubber boots.","In 2025, the company YKK announced a tapeless zipper whose teeth attach directly to the garment fabric."],"where":[],"whereNote":null,"sources":[{"title":"Zipper","url":"https://en.wikipedia.org/wiki/Zipper"},{"title":"Sewing thread","url":"https://en.wikipedia.org/wiki/Sewing_thread"}],"license":"https://creativecommons.org/licenses/by-sa/4.0/"}],"processes":[{"slug":"mine","name":"Mining","blurb":"Rock is blasted, dug or cut out of the ground and hauled to a plant. Most of what comes up is waste, so the next step is nearly always separating the useful part from the rest.","uses":["baking-soda","bauxite","borax","brick","cement","chromite","chromium","cinnabar","clay","coal","cobalt","cobalt-ore","concrete","copper-ore","crude-oil","dolomite","drywall","feldspar","fluorspar","gold","gold-ore","granite","kitchen-countertop","gravel","gypsum","iron-ore","kaolin","lead-ore","limestone","manganese","manganese-ore","marble","mica","natural-graphite","nickel-ore","phosphate-rock","pigment","plaster","platinum","platinum-ore","potash","quartz","lime","rare-earth-ore","rock-salt","roof-tile","rough-diamond","silica-sand","silver","silver-ore","spodumene","sulfur","table-salt","tin","tin-ore","titanium-ore","trona","tungsten-ore","zinc-ore"]},{"slug":"drill","name":"Drilling and pumping","blurb":"A well is bored down to a reservoir and the liquid or gas is brought to the surface, by its own pressure at first and by pumps after that.","uses":["bottled-water","crude-oil","lithium-brine","lithium-carbonate","natural-gas","seawater","skyscraper","sulfur","water"]},{"slug":"harvest","name":"Harvesting","blurb":"A crop or animal product is gathered at the moment it is worth most. Timing matters more than speed, because quality starts to fall as soon as the crop is cut or picked.","uses":["almonds","apples","bamboo","barley","beeswax","tea","agave","cabbage","canned-tuna","carnauba","castor-beans","cattle","cattle-hide","chickens","chili-pepper","cocoa-beans","coconut-milk","coconut-oil","coffee-cherries","cork-bark","corn","cricket-bat","cucumber","cultured-pearl","dartboard","down","durum-wheat","eggs","flax","frozen-peas","gelatin","green-tea","hazelnuts","honey","honeycomb","hops","hot-sauce","incense","indigo-plant","juniper-berries","lacquer","licorice","linen","maple-sap","maple-syrup","matcha","mezcal","popcorn","mustard-seed","natural-latex","nori","oats","oil-palm-fruit","olives","onions","oranges","palm-oil","pasteurized-milk","peanuts","pearl-oyster","peas","perfume","pigs","port-wine","potatoes","prosecco","rapeseed","raw-cotton","raw-milk","rice","coffee","rye","sausage-casing","seaweed","silk-cocoons","soybeans","steel-scrap","sugar-beet","sugarcane","tea-leaves","tequila","timber","tomatoes","tonic-water","tuna-fish","utility-pole","vanilla-extract","vanilla-pods","wheat","white-rice","whitefish","wine","grapes","fleece","wool-yarn"]},{"slug":"crush","name":"Crushing and grinding","blurb":"Jaws, rollers or tumbling steel balls break a solid into smaller pieces. Smaller pieces have more surface, so they melt, dissolve and react faster.","uses":["acetaminophen","almond-milk","alumina","road","bauxite","tea","chalk","borax","brick","canned-meat","carnauba","cellulose-acetate","cement","chili-pepper","chocolate","chromite","cocoa-butter","cocoa-powder","coconut-milk","copper","copper-ore","corn-flakes","corn-starch","dolomite","ethanol","feldspar","flour","fluorspar","gold","gravel","gypsum","hard-cider","hazelnuts","hot-dog","hot-sauce","instant-coffee","iron-ore","jam","lead","lead-ore","limestone","linen","lithium-carbonate","manganese","manganese-ore","mdf","mercury","silicon","mezcal","mica","mustard","natural-graphite","neodymium-magnet","nickel","nickel-ore","nori","oat-milk","olive-oil","palm-oil","pasta","phosphoric-acid","plaster","platinum-ore","polysilicon","popping-candy","potash","printer-toner","quartz","lime","rayon","rock-salt","rough-diamond","salami","sausage-casing","semolina","silicone","silver-ore","soy-milk","steel-scrap","superabsorbent-polymer","tequila","tin","tofu","toothpaste","trichlorosilane","trona","tungsten","tungsten-ore","vegetable-oil","wine","wood-pellets","zinc-ore"]},{"slug":"separate","name":"Separating and sifting","blurb":"Screens, spinners, magnets, air streams or froth split a mixture by size, density or surface chemistry.","uses":["acetaminophen","acetic-anhydride","acrylic-acid","air","almond-milk","almonds","alumina","aluminum","aluminum-foil","argon","aspirin","yeast","balloon","beer","beeswax","benzene","biodiesel","tea","bleach","borax","bottled-water","brown-sugar","butter","caffeine","carbon-black","carbon-monoxide","cast-iron-pan","castor-beans","caustic-soda","champagne","chewing-gum","chromite","clay","cobalt","cobalt-ore","coconut-milk","coconut-oil","coconuts","coke","condensed-milk","contact-lens","copper","copper-ore","corn-starch","corn-syrup","cotton-swab","cotton-yarn","cough-syrup","cream","cream-cheese","decaf-coffee","down","durum-wheat","energy-drink","ethanol","feldspar","fertilizer","fishing-rod","flour","fluorspar","frozen-peas","gallium","germanium","gin","glycerin","gold","gold-ore","gravel","gummy-bears","gypsum","hazelnut-spread","hexane","honey","honeycomb","hot-sauce","hydrogen","hydrogen-peroxide","imitation-crab","indium","ink","instant-coffee","insulin","iridium","iron-ore","jet-fuel","ketchup","kimchi","kombucha","lacquer","lead","lead-ore","linen","linseed-oil","lithium-brine","lithium-carbonate","magnesium","malted-barley","manganese-ore","maple-syrup","mead","popcorn","molasses","motor-oil","vaccine","natural-graphite","neon","nickel","nickel-ore","non-alcoholic-beer","oat-milk","olive-oil","orange-juice","palm-oil","p-xylene","paraffin-wax","pasteurized-milk","peanut-butter","peanuts","penicillin","pentane","perfume","phosphate-rock","phosphoric-acid","photoresist","pig-iron","pillow","platinum","platinum-ore","polyethylene","polypropylene","popping-candy","port-wine","potash","powdered-milk","printer-toner","propane","prosecco","quartz","rare-earth-ore","refrigerant","coffee","oatmeal","rough-diamond","rye","sausage-casing","seawater","semolina","thread","silica-sand","silver","silver-ore","soap","soda-ash","soy-milk","sparkling-water","spodumene","water-bottle","steel","steel-scrap","sugar","synthetic-rubber","tin","tin-ore","titanium-dioxide","titanium-ore","tofu","toluene","tungsten-ore","thermos","vegetable-oil","vinegar","vitamin-c","vodka","rubber","water","white-rice","wine","wood-pellets","fleece","wool-yarn","zinc","zinc-ore","zinc-oxide"]},{"slug":"wash","name":"Washing and cleaning","blurb":"Water, solvent or steam carries away dirt and leftover chemicals before the next step can be spoiled by them.","uses":["acetaminophen","alumina","aluminum-can","ammonia","aspirin","balloon","bamboo","towel","biodiesel","borax","brown-sugar","caffeine","canned-meat","carbon-monoxide","carnauba","cattle-hide","chlorine","chromium","coal","condom","contact-lens","copper-ore","copper-wire","corn-starch","cream","decaf-coffee","diesel","double-glazed-window","down","energy-drink","epoxy","feldspar","flour","french-fries","frozen-peas","gelatin","glycerin","gold-ore","hydrogen","imitation-crab","salsa","jeans","kaolin","ketchup","kevlar","kitchen-sponge","leather","winter-gloves","linseed-oil","lng","lithium-carbonate","malted-barley","manganese-ore","mustard","nail","naphtha","nichrome","nitrile-glove","nitrogen","nonstick-pan","olive-oil","medal","orange-juice","oxygen","phosphate-rock","photoresist","pickles","pigment","polycarbonate","potato-chips","rare-earth-ore","rayon","coffee","safety-pin","sausage-casing","semolina","sheet-steel","silica-sand","silver-ore","socks","solar-panel","stainless-steel","fork","water-bottle","steel-wire","sugar","sulfuric-acid","sunglasses","suit","tennis-ball","tinplate","tofu","tortilla","vanadium","water","whitefish","cork-stopper","wood-pulp","sweater","wool-yarn"]},{"slug":"mix","name":"Mixing and blending","blurb":"Ingredients are measured and stirred until the batch is the same all the way through. Every later step depends on that consistency.","uses":["aa-battery","abs-plastic","acrylic-acid","adhesive","air-freshener","almond-milk","asphalt","road","aspirin","asthma-inhaler","baby-formula","bacon","baguette","baking-soda","ballpoint-pen","banknote","basketball","beef-jerky","beer","biodiesel","chalk","bleach","bourbon","bowling-ball","brake-pad","brass","bread","bronze","brown-sugar","cake-mix","candle","canned-meat","canned-soup","caramel","caramel-color","carbon-black","caustic-soda","cellulose-acetate","ceramic","floor-tile","champagne","cheddar","cheese","chicken-nuggets","chlorine","chocolate","cognac","coke","cola","concrete","condensed-milk","condom","contact-lens","cotton-candy","cotton-yarn","cough-syrup","crackers","crayon","cream","cream-cheese","croissant","deodorant","diesel","dinner-plate","dish-soap","diaper","drywall","duct-tape","e-reader","egg-carton","energy-drink","pencil-eraser","ethylene","eyeshadow","facial-tissue","felt-hat","ferrite","fertilizer","fiberglass","fireworks","flip-flops","flour","frisbee","formaldehyde","foundation-makeup","frozen-pizza","gasoline","gelatin-capsule","gelatin-dessert","gin","glass","glass-bottle","marble-toy","golf-ball","granola-bar","green-tea","gummy-bears","hair-dye","hairspray","ham","hard-cider","hazelnut-spread","highlighter","hockey-puck","honey","hot-dog","hot-sauce","hydrochloric-acid","hydrogen-peroxide","ibuprofen","ice-cream","imitation-crab","incense","indium-tin-oxide","ink","insect-repellent","instant-noodles","insulin","jam","salsa","jet-fuel","kevlar","kimchi","kitchen-sponge","koji","kombucha","synthetic-diamond","lacquer","detergent","lego-brick","light-beer","lipstick","lithium-ion-cell","lollipop","magnesium","margarine","marker-pen","marshmallow","mascara","mayonnaise","mdf","mead","silicon","modeling-clay","motor-oil","mouthwash","vaccine","mustard","nail-polish","nitric-acid","nylon","oat-milk","orange-juice","paint","palm-oil","paper","parmesan","pasta","peanut-butter","pencil","penicillin","perfume","phenolic-resin","photoresist","pickles","pigment","plastic","plastic-straw","plastic-wrap","polycarbonate","polyethylene","polypropylene","polyurethane","polyvinyl-alcohol","pvb","popping-candy","porcelain","port-wine","potassium-hydroxide","pretzel","printer-toner","propane","pvc","pvc-pipe","rayon","refrigerant","roof-tile","root-beer","rubber-boots","rum","salami","sandwich-cookie","sauerkraut","sausage","scotch","shampoo","soap","soda","soda-ash","solder","sour-cream","sourdough","soy-milk","spandex","sparkling-water","sprinkles","styrene","polystyrene-foam","sulfuric-acid","sunscreen","super-glue","superabsorbent-polymer","synthetic-graphite","table-salt","tampon","tennis-ball","toffee","toilet","toilet-paper","tonic-water","toothpaste","trading-cards","tungsten-carbide","vanilla-extract","vinegar","vinyl-floor","vodka","rubber","whiskey","white-chocolate","window-glass","yoga-mat","yogurt"]},{"slug":"knead","name":"Kneading and working","blurb":"A paste or dough is folded and stretched to build its internal structure, whether that is gluten in bread or polymer chains in rubber.","uses":["bagel","bread","butter","candy-cane","cheddar","chewing-gum","chocolate","donut","duct-tape","felt-hat","green-tea","hockey-puck","instant-noodles","koji","modeling-clay","mozzarella","olive-oil","rubber-band","silicone","pottery","tire","toilet-paper","rubber","white-chocolate","blanket"]},{"slug":"melt","name":"Melting and smelting","blurb":"Heat turns a solid into a liquid. In smelting, a chemical reaction also strips the metal away from the oxygen or sulfur it is bound to.","uses":["3d-printer-filament","adhesive","aluminum","beeswax","brass","bronze","bell","bubble-wrap","camera-lens","candle","carbon-black","cast-iron-pan","chewing-gum","chromium","cobalt","copper","cotton-candy","crayon","deodorant","toy-car","fiberglass","insulation","flute","frisbee","foundation-makeup","glass","glass-bottle","marble-toy","gold","gold-bar","gold-ring","golf-club","iridium","lead","lego-brick","lipstick","magnesium","manganese","mascara","silicon","naphtha","neodymium-magnet","nichrome","nickel","optical-fiber","pacemaker","phosphoric-acid","pig-iron","plastic-bag","plastic-bottle","plastic-wrap","platinum","polyester","printer-toner","pvc-pipe","silicon-wafer","silver","smartphone-glass","solder","stained-glass","stainless-steel","polystyrene-foam","sulfuric-acid","sunscreen","tin","titanium","toothbrush","turbine-blade","vanadium","vinyl-record","window-glass","zinc-oxide","zip-bag"]},{"slug":"refine","name":"Refining and distilling","blurb":"A mixture is heated so its parts boil off at different temperatures, or treated so the impurities drop out. What remains is purer and worth more.","uses":["acetic-anhydride","acetone","acrylic-acid","air","argon","asphalt","baking-soda","benzene","bourbon","caffeine","carbon-monoxide","caustic-soda","cobalt","cocoa-butter","coconut-oil","cognac","condensed-milk","copper","corn-syrup","diesel","ethanol","ethylene","ethylene-glycol","gallium","gasoline","gelatin","germanium","gin","glycerin","gold","hexane","hydrogen","hydrogen-peroxide","ibuprofen","indium","instant-coffee","insulin","jam","jet-fuel","lead","licorice","margarine","mercury","silicon","methanol","mezcal","motor-oil","mouthwash","vaccine","naphtha","natural-gas","neon","neon-sign","nickel","nitric-acid","nitrogen","orange-juice","oxygen","palm-oil","p-xylene","paraffin-wax","penicillin","pentane","perfume","petroleum-coke","phenol","pig-iron","plasticizer","polyethylene","polypropylene","polysilicon","polystyrene","polyvinylpyrrolidone","powdered-milk","propane","propylene","quartz","rail","refrigerant","rum","scotch","silicone","silver","soap","soda-ash","stainless-steel","steel","styrene","sugar","sulfur","super-glue","synthetic-rubber","table-salt","tequila","titanium","titanium-dioxide","toluene","tonic-water","trichlorosilane","vegetable-oil","vodka","whiskey","white-chocolate","wood-pulp","zinc"]},{"slug":"react","name":"Chemical reaction","blurb":"Molecules are combined or broken apart in a reactor, usually with heat, pressure and a catalyst, to create a substance that was not there before.","uses":["abs-plastic","acetaminophen","acetic-anhydride","acetone","acrylic","acrylic-acid","adhesive","alumina","ammonia","aspirin","bacon","baking-soda","benzene","billiard-ball","biodiesel","tea","bleach","bottled-water","caffeine","carbon-black","carbon-dioxide","carbon-fiber","carbon-monoxide","cellulose-acetate","cement","cheese","chromium","cobalt","cobalt-ore","cocoa-powder","contact-lens","corn-starch","corn-syrup","deodorant","diesel","drywall","energy-drink","epoxy","ethanol","ethylene","ethylene-glycol","fertilizer","formaldehyde","gallium","gasoline","gelatin","germanium","glass-bottle","glycerin","gold","hair-dye","hexane","hydrochloric-acid","hydrogen","hydrogen-peroxide","ibuprofen","indigo-plant","indium","insect-repellent","insulin","iridium","jet-fuel","kevlar","kitchen-sponge","detergent","leather","leggings","light-beer","lithium-carbonate","manganese","margarine","melamine-resin","mercury","methanol","motor-oil","vaccine","nail-polish","naphtha","nitric-acid","nylon","oat-milk","optical-fiber","p-xylene","paraffin-wax","penicillin","pentane","pet-plastic","petroleum-coke","phenol","phenolic-resin","phosphoric-acid","photoresist","pig-iron","pigment","plaster","plastic","plasticizer","platinum","polycarbonate","polyethylene","polypropylene","polysilicon","polystyrene","polyurethane","polyvinyl-alcohol","pvb","polyvinylpyrrolidone","propylene","ptfe","pvc","lime","rayon","refrigerant","root-beer","shampoo","silicone","smartphone-glass","soap","soda","soda-ash","solar-cell","spandex","steel","styrene","sulfuric-acid","sunscreen","super-glue","superabsorbent-polymer","synthetic-rubber","titanium","titanium-dioxide","tofu","toluene","tonic-water","trichlorosilane","tungsten","tungsten-carbide","vanadium","vitamin-c","wood-pulp","zinc","zinc-oxide"]},{"slug":"electrolyze","name":"Electrolysis","blurb":"An electric current is pushed through a liquid or molten salt, pulling elements apart and collecting them at the electrodes.","uses":["aluminum","bleach","caustic-soda","chlorine","copper","hydrogen","iridium","manganese","nickel","potassium-hydroxide","silver","zinc"]},{"slug":"ferment","name":"Fermenting","blurb":"Yeast or bacteria feed on sugars and leave behind alcohol, acid or gas. The factory's job is to keep the microbes comfortable.","uses":["baguette","yeast","beer","bourbon","bread","carbon-dioxide","champagne","cheddar","cheese","chocolate","cocoa-beans","cocoa-butter","cocoa-powder","cognac","crackers","cream-cheese","croissant","donut","ethanol","gin","hard-cider","hot-sauce","indigo-plant","insulin","kimchi","kombucha","light-beer","linen","mead","mezcal","mozzarella","mustard","non-alcoholic-beer","penicillin","pickles","port-wine","pretzel","prosecco","rum","sake","salami","sauerkraut","scotch","sour-cream","sourdough","soy-sauce","tequila","vinegar","vitamin-c","vodka","whiskey","wine","yogurt"]},{"slug":"cook","name":"Cooking and boiling","blurb":"Heat in a liquid drives off water, changes proteins and sugars, and kills microbes.","uses":["bacon","bagel","beer","brown-sugar","candy-cane","canned-meat","canned-soup","canned-tuna","caramel","caramel-color","cheddar","cheese","chicken-nuggets","cola","corn-flakes","corn-syrup","cough-syrup","cream-cheese","decaf-coffee","donut","ethanol","fish-sticks","formaldehyde","french-fries","frozen-peas","gelatin","gelatin-dessert","green-tea","gummy-bears","ham","hot-dog","imitation-crab","instant-noodles","jam","salsa","jelly-beans","ketchup","kitchen-sponge","koji","kombucha","lacquer","licorice","light-beer","linseed-oil","lollipop","maple-syrup","marshmallow","matcha","mdf","mezcal","modeling-clay","molasses","mozzarella","non-alcoholic-beer","wine-barrel","palm-oil","parmesan","petroleum-coke","phosphoric-acid","popping-candy","popsicle-stick","potassium-hydroxide","potato-chips","oatmeal","sake","sausage","silk","soy-milk","soy-sauce","sugar","table-salt","toffee","tofu","tortilla","vanilla-extract","vodka","cork-stopper"]},{"slug":"bake","name":"Baking and roasting","blurb":"Dry heat sets a structure and browns the surface. Browning creates much of the flavor.","uses":["airplane","aluminum","bagel","baguette","tea","bread","cake-mix","charcoal","chocolate","cobalt","cocoa-butter","cocoa-powder","coke","corn-flakes","crackers","croissant","decaf-coffee","frozen-pizza","granola-bar","green-tea","hazelnut-spread","lithium-carbonate","nori","wine-barrel","peanut-butter","pretzel","coffee","oatmeal","sandwich-cookie","sourdough","soy-sauce","tequila","tortilla","vanadium","zinc"]},{"slug":"fire","name":"Kiln firing","blurb":"A shaped mineral body is heated until its particles fuse, turning something crumbly into something hard and permanent.","uses":["alumina","brick","bronze-statue","carbon-dioxide","cement","ceramic","floor-tile","chromium","coffee-mug","thermometer","dinner-plate","ferrite","germanium","gold-ring","indium","indium-tin-oxide","iridium","magnesium","manganese-ore","neodymium-magnet","pencil","petroleum-coke","platinum","porcelain","lime","roof-tile","soda-ash","spark-plug","stained-glass","pottery","synthetic-graphite","toilet","tungsten-carbide"]},{"slug":"dry","name":"Drying and curing","blurb":"Water or solvent leaves slowly, or a chemical hardening runs its course. Rushing this step usually causes cracks and warps.","uses":["3d-printer-filament","abs-plastic","guitar","acrylic","asphalt","road","baby-formula","yeast","baking-soda","beef-jerky","beer","tea","chalk","borax","bourbon","bowling-ball","brake-pad","brick","candy-coated-chocolate","car-battery","cardboard","cattle-hide","cellulose-acetate","ceramic","floor-tile","cheese","chili-pepper","clay","cocoa-beans","cocoa-butter","coconut-oil","coconuts","cognac","concrete","copra","cork-bark","corn-flakes","corn-starch","cricket-bat","dartboard","decaf-coffee","denim","dinner-plate","down","drumstick","drywall","egg-carton","transformer","epoxy","facial-tissue","fiberglass","insulation","fireworks","fishing-rod","flax","foam-cup","french-fries","garden-hose","gelatin","gelatin-capsule","green-tea","gummy-bears","ham","hard-cider","hardwood-floor","hockey-puck","honey","hops","incense","instant-coffee","instant-noodles","jelly-beans","juniper-berries","kaolin","lacquer","detergent","lead-ore","leather","licorice","lithium-brine","lithium-carbonate","lithium-ion-cell","lumber","malted-barley","matcha","mead","popcorn","non-alcoholic-beer","nori","wine-barrel","onions","oranges","paper","paper-straw","parmesan","pasta","pet-plastic","plastic-bottle","platinum-ore","plywood","polyester","polyurethane","polyvinyl-alcohol","pvb","polyvinylpyrrolidone","port-wine","potato-chips","potatoes","powdered-milk","ptfe","pvc","raw-cotton","coffee","roof-tile","rum","rye","sake","salami","sausage-casing","scotch","seawater","silica-sand","silk","soap","pottery","sugar","superabsorbent-polymer","surfboard","tequila","toilet","toilet-paper","toothpick","tungsten","ukulele","utility-pole","vanilla-extract","rubber","wallpaper","whiskey","white-rice","wine","cork-stopper","wood-pellets","wood-pulp","wooden-chair","wooden-spoon","sweater"]},{"slug":"chill","name":"Chilling and freezing","blurb":"Cold slows microbes, sets fats and locks in a shape or structure that heat created.","uses":["3d-printer-filament","air","ammonia","apples","argon","bacon","bagel","baguette","beer","butter","cabbage","candle","canned-meat","canned-soup","carbon-black","carbon-dioxide","cement","champagne","charcoal","chicken-nuggets","chlorine","coke","condensed-milk","cotton-candy","crayon","donut","ethylene","fish-sticks","frisbee","foam-cup","foundation-makeup","french-fries","frozen-peas","frozen-pizza","garden-hose","gelatin-dessert","green-tea","ham","hot-dog","ice-cream","instant-coffee","salsa","ketchup","kimchi","lego-brick","lipstick","lng","lollipop","margarine","marshmallow","melamine-resin","mercury","methanol","neon","nitric-acid","nitrogen","oxygen","paraffin-wax","peas","petroleum-coke","plastic-bag","plastic-straw","popping-candy","power-cable","printer-toner","propylene","pvc-pipe","lime","rail","coffee","sandwich-cookie","sour-cream","sparkling-water","sunscreen","toffee","tortilla","trichlorosilane","vinyl-floor","vinyl-record","white-chocolate","whitefish","yoga-mat","yogurt","zip-bag"]},{"slug":"cast","name":"Casting","blurb":"A liquid is poured into a mold or onto a moving surface and left to solidify. It is the shortest route from a molten material to a useful shape.","uses":["acrylic","aluminum","aluminum-foil","road","banknote","beeswax","billiard-ball","chalk","bowling-ball","brass","bronze","bell","bronze-statue","button","candle","car-battery","car-engine","cardboard","cast-iron-pan","ceiling-fan","chromium","concrete","copper-wire","crayon","deodorant","toy-car","digital-camera","drum-kit","dumbbell","facial-tissue","faucet","fiberglass","gallium","gold-bar","gold-ring","golf-club","indium","lead","licorice","lipstick","magnesium","manganese","silicon","motorcycle","neodymium-magnet","nori","paper","paraffin-wax","piano","pig-iron","polyurethane","potassium-hydroxide","rail","rebar","skateboard","snow-globe","solder","stainless-steel","steel","steel-beam","pottery","tin","toffee","toilet","toilet-paper","turbine-blade","washing-machine","wind-turbine","window-glass","zinc"]},{"slug":"mold","name":"Molding","blurb":"Soft material is forced into a cavity under pressure. Once the expensive mold exists, each extra part is very cheap.","uses":["guitar","action-figure","football","backpack","bagel","baguette","balloon","ballpoint-pen","baseball","basketball","bike-helmet","chalk","blender","bread","bell","bronze-statue","bubble-wrap","drone","camera-lens","candy-cane","candy-coated-chocolate","canoe","cardboard","cast-iron-pan","cello","ceramic","chicken-nuggets","chocolate","compact-disc","computer-keyboard","computer-mouse","condom","contact-lens","croissant","dental-floss","globe","dice","toy-car","thermometer","dinner-plate","dishwasher","egg-carton","electric-kettle","electric-toothbrush","eyeglass-lens","fashion-doll","faucet","fertilizer","flip-flops","frisbee","foam-cup","fountain-pen","gelatin-dessert","glass","glass-jar","gold-ring","golf-ball","golf-club","gummy-bears","suitcase","harmonica","headphones","hearing-aid","high-heels","highlighter","hiking-boots","hockey-puck","ice-cream","ice-skates","inkjet-printer","instant-coffee","jelly-beans","laptop","leather-shoe","led","lego-brick","light-switch","lollipop","loudspeaker","marker-pen","mattress","mdf","n95-mask","nitrile-glove","office-chair","paper-cup","parmesan","pasteurized-milk","phone-charger","plastic","plastic-bottle","plastic-straw","polystyrene","porcelain","power-outlet","pretzel","prosthetic-leg","ptfe","refrigerator","remote-control","roller-skates","rubber-boots","rubiks-cube","sailboat","sandwich-cookie","ski","smoke-detector","sneaker","soccer-ball","sourdough","pottery","polystyrene-foam","sunglasses","surfboard","syringe","television","tennis-ball","tennis-racket","tire","toothbrush","trumpet","turbine-blade","ukulele","usb-cable","vacuum-cleaner","game-console","vinyl-record","violin","volleyball","rubber","washing-machine","water-heater","white-chocolate","wireless-earbuds","yo-yo","zipper"]},{"slug":"blow","name":"Blowing","blurb":"Air pressure inflates a hot blob against a mold wall or into a thin film, giving a hollow shape with very little material.","uses":["bottled-water","foam-cup","glass-bottle","glass-jar","light-bulb","neon-sign","plastic-bag","plastic-bottle","snow-globe","stained-glass","water-bottle","zip-bag"]},{"slug":"extrude","name":"Extruding","blurb":"Material is pushed through a shaped opening, like toothpaste from a tube, and comes out as a continuous length with the same cross-section.","uses":["adhesive","ladder","aluminum-window-frame","brass","brick","bubble-wrap","carpet","chewing-gum","clear-tape","coffee-mug","cotton-swab","dental-floss","dinner-plate","donut","duct-tape","pencil-eraser","garden-hose","graphics-card","suitcase","hockey-puck","incense","marshmallow","n95-mask","pacemaker","pasta","pencil","plastic-straw","plastic-wrap","polycarbonate","pvb","power-cable","pretzel","pvc","pvc-pipe","rayon","rubber-band","sausage-casing","thread","soap","sprinkles","polystyrene-foam","synthetic-graphite","tire","toffee","usb-cable","wood-pellets"]},{"slug":"roll","name":"Rolling","blurb":"Material passes between turning rollers that squeeze it thinner and longer, sheet after sheet or bar after bar.","uses":["aluminum-foil","road","barbed-wire","bolt","candy-cane","chewing-gum","coin","corn-flakes","crackers","croissant","elevator","facial-tissue","insulation","fishing-rod","frozen-pizza","marble-toy","inflatable-pool-toy","instant-noodles","lithium-ion-cell","wristwatch","microwave-oven","newspaper","nichrome","medal","pvb","rail","razor-blade","rebar","oatmeal","saxophone","screw","sheet-steel","shipping-container","slinky","smoke-detector","spark-plug","stainless-steel","fork","staple","steel-beam","steel-pipe","steel-wire","swimsuit","tinplate","tire","tortilla","vinyl-floor","water-heater","white-chocolate","wind-turbine","window-glass"]},{"slug":"draw","name":"Drawing","blurb":"A rod or fiber is pulled through a narrowing die or from a hot source, which makes it thinner, longer and often stronger.","uses":["3d-printer-filament","barbed-wire","coil-spring","copper-wire","cotton-yarn","fiberglass","flute","gas-cylinder","guitar-string","stent","light-bulb","nichrome","nylon","optical-fiber","paperclip","piano","plastic-wrap","polyester","power-cable","pressure-cooker","saxophone","needle","thread","silk","smartphone-glass","solder","staple","chain","steel-wire","syringe","toothbrush","trumpet","tungsten","usb-cable","thermos","wire-rope"]},{"slug":"forge","name":"Forging","blurb":"Hammers or presses squeeze hot metal into shape. The metal's grain follows the part's outline, which makes it tough.","uses":["air-conditioner","airplane","ball-bearing","blender","bolt","bronze","drill-bit","drum-kit","fire-extinguisher","gas-cylinder","hammer","hip-implant","jet-engine","locomotive","nail","nichrome","scissors","screw","needle","spark-plug","water-bottle","steel-pipe","titanium","wrench"]},{"slug":"stamp","name":"Stamping and pressing","blurb":"A die closes on a blank and cuts or bends it in a fraction of a second. High-volume lines can do this hundreds of times a minute.","uses":["aa-battery","air-conditioner","aluminum-can","ladder","football","asthma-inhaler","ball-bearing","baseball-bat","basketball","board-game","brake-pad","button","car","cardboard-box","ceiling-fan","clothespin","coin","crackers","credit-card","dishwasher","hinge","electric-car","electric-kettle","electric-motor","envelope","fire-extinguisher","flip-flops","fountain-pen","gas-cylinder","gold-bar","harmonica","jigsaw-puzzle","key","kitchen-knife","leather-belt","winter-gloves","light-switch","loudspeaker","mattress","microwave-oven","nonstick-pan","medal","padlock","paper-cup","paperclip","pizza-box","power-outlet","pressure-cooker","razor-blade","safety-pin","saxophone","needle","shipping-container","shovel","slinky","smoke-detector","soap","fork","staple","toaster","toothpick","trumpet","usb-cable","washing-machine","wheelbarrow","cork-stopper","wrench"]},{"slug":"press","name":"Squeezing and pressing out","blurb":"Pressure forces liquid out of a solid, or packs loose powder into a solid tablet or block.","uses":["aa-battery","aluminum-can","ladder","aluminum-window-frame","ammonia","road","roof-shingle","aspirin","yeast","baseball","brake-pad","canned-soup","canoe","carbon-dioxide","floor-tile","chain-link-fence","champagne","cheddar","cheese","cocoa-butter","cocoa-powder","coconut-milk","coconut-oil","coffee-mug","cognac","coil-spring","cotton-candy","cotton-fabric","cricket-bat","dartboard","denim","thermometer","dinner-plate","hinge","dumbbell","egg-carton","ethylene","eyeglass-frame","eyeshadow","felt-hat","ferrite","fishing-rod","gold-bar","granola-bar","hard-cider","headphones","high-heels","hiking-boots","ibuprofen","indium-tin-oxide","synthetic-diamond","laminate-floor","winter-gloves","wallet","light-switch","linseed-oil","mdf","melamine-resin","microphone","molasses","neodymium-magnet","neon","nitrogen","medal","orange-juice","oxygen","pacemaker","palm-oil","paper","phenolic-resin","piano","pizza-box","plywood","power-outlet","pressure-cooker","rail","roof-tile","rum","safety-pin","sake","sanitary-pad","sauerkraut","saw-blade","shovel","silk-tie","skateboard","snowboard","soy-sauce","spark-plug","fork","chain","sugar","sunglasses","suspension-bridge-cable","synthetic-rubber","suit","tampon","tin-can","tofu","tortilla","treadmill","tungsten","tungsten-carbide","utility-pole","vegetable-oil","vinyl-floor","vitamin-c","wet-wipes","wheelbarrow","windshield","wine"]},{"slug":"machine","name":"Machining","blurb":"Cutting tools remove material until only the part remains. It is slower than forming but reaches very tight tolerances.","uses":["guitar","action-figure","airplane","ball-bearing","ballpoint-pen","baseball-bat","billiard-ball","bowling-ball","brass","bronze","bell","bronze-statue","button","car-engine","cello","chess-set","chopsticks","clothespin","coil-spring","credit-card","cricket-bat","dice","toy-car","hinge","drum-kit","dumbbell","electric-guitar","eyeglass-frame","faucet","frisbee","gas-cylinder","kitchen-countertop","hammer","suitcase","hardwood-floor","harmonica","hip-implant","light-bulb","jigsaw-puzzle","key","laminate-floor","leather-belt","handbag","wallet","loudspeaker","lumber","wristwatch","nail","wine-barrel","medal","rocket","padlock","pencil","plywood","popsicle-stick","power-outlet","pressure-cooker","printed-circuit-board","prosthetic-leg","saxophone","scissors","skateboard","ski","smartwatch","steel-wire","subway-train","sunglasses","surfboard","synthetic-graphite","tennis-racket","toothpick","trumpet","turbine-blade","utility-pole","thermos","vinyl-record","violin","wheelchair","white-rice","wooden-chair","door","wooden-spoon","blanket","wrench","yo-yo"]},{"slug":"grind","name":"Grinding and polishing","blurb":"Abrasives take off tiny amounts of material, giving a precise dimension or a smooth, reflective surface.","uses":["ball-bearing","billiard-ball","bowling-ball","brake-pad","button","cake-mix","camera-lens","cast-iron-pan","cement","chess-set","chopsticks","clothespin","cocoa-powder","coil-spring","cricket-bat","cultured-pearl","cut-diamond","dartboard","dice","toy-car","drill-bit","drumstick","eyeglass-frame","eyeglass-lens","eyeshadow","faucet","felt-hat","ferrite","flour","foundation-makeup","fountain-pen","gold-ring","golf-ball","golf-club","granite","kitchen-countertop","hard-drive","harmonica","hip-implant","ice-skates","incense","indium-tin-oxide","ink","jet-engine","kitchen-knife","synthetic-diamond","wallet","lipstick","marble","mascara","matcha","mayonnaise","mdf","wristwatch","mustard","nail-polish","nonstick-pan","wine-barrel","paint","paper","peanut-butter","phenolic-resin","pigment","plaster","plywood","popsicle-stick","pressure-cooker","lime","rare-earth-ore","razor-blade","safety-pin","sake","sanitary-pad","saw-blade","scissors","screw","semolina","needle","silicon-wafer","ski","snow-globe","snowboard","stained-glass","fork","sunglasses","sunscreen","surfboard","tennis-racket","toothbrush","toothpick","tortilla","tungsten-carbide","ukulele","white-rice","windshield","cork-stopper","wooden-chair","door","wooden-spoon","wrench","zinc-ore"]},{"slug":"cut","name":"Cutting and slitting","blurb":"Blades, wires, lasers or water jets divide a big piece into many smaller ones.","uses":["acrylic","adhesive-bandage","airbag","aluminum-foil","aluminum-window-frame","football","roof-shingle","backpack","bacon","baguette","banknote","baseball","baseball-bat","baseball-cap","basketball","beef-jerky","bicycle","bike-helmet","board-game","bolt","book","bread","brick","button","camera-sensor","candy-cane","canned-soup","canned-tuna","caramel","cardboard","cardboard-box","carpet","cattle-hide","ceiling-fan","chain-link-fence","cheddar","cheese","chess-set","chewing-gum","chicken-nuggets","chopsticks","clear-tape","clothespin","coffee-mug","container-ship","copra","cotton-candy","cricket-bat","croissant","curtain","cut-diamond","dental-floss","globe","dice","dishwasher","diaper","double-glazed-window","dress-shirt","drill-bit","drumstick","drywall","duct-tape","dumbbell","electric-guitar","transformer","envelope","pencil-eraser","eyeglass-lens","faucet","fish-sticks","fishing-rod","flag","frisbee","fountain-pen","french-fries","glass-bottle","glass-jar","marble-toy","golf-club","granite","kitchen-countertop","granola-bar","ham","hammer","hardwood-floor","stent","high-heels","hiking-boots","hockey-puck","hoodie","velcro","hot-dog","ice-skates","imitation-crab","inflatable-pool-toy","instant-noodles","salsa","jeans","kimchi","kitchen-sponge","kite","lcd-screen","leather-belt","winter-gloves","handbag","leather-shoe","wallet","led","leggings","lithium-ion-cell","lumber","marble","marshmallow","match","mdf","mica","microchip","mirror","mozzarella","nail","newspaper","olives","onions","paper","paper-bag","paper-cup","paper-straw","paperclip","parmesan","pasta","pencil","pet-plastic","petroleum-coke","pillow","plastic","plastic-straw","plastic-wrap","playing-cards","polyester","polyethylene","polypropylene","polyurethane","popsicle-stick","potato-chips","pressure-cooker","pvc-pipe","rail","raincoat","razor-blade","rebar","rubber-band","rubber-boots","safety-pin","sanitary-pad","sauerkraut","sausage","saw-blade","saxophone","screw","needle","shoelace","silicon-wafer","silk-tie","skateboard","ski","smartphone-glass","sneaker","snowboard","soccer-ball","sofa","solar-cell","solar-panel","sprinkles","stained-glass","stainless-steel","fork","water-bottle","staple","chain","steel-beam","steel-pipe","steel-scrap","sticky-notes","polystyrene-foam","subway-train","sunglasses","superabsorbent-polymer","surfboard","swimsuit","t-shirt","suit","teddy-bear","tennis-ball","tennis-racket","timber","tin-can","tinplate","toffee","toilet","toilet-paper","toothbrush","toothpick","trading-cards","ukulele","umbrella","underwear","usb-cable","vinyl-floor","vinyl-record","volleyball","wet-wipes","wheelbarrow","wheelchair","whitefish","window-glass","windshield","wood-pulp","wooden-spoon","wrench","yoga-mat","zip-bag","zipper"]},{"slug":"spin","name":"Spinning fiber","blurb":"Loose fibers are drawn out and twisted into yarn, or a liquid is forced through tiny holes and hardened into filament.","uses":["barbed-wire","baseball","towel","carbon-fiber","cellulose-acetate","cotton-candy","cotton-yarn","dartboard","dental-floss","dress-shirt","insulation","guitar-string","hoodie","velcro","kevlar","leggings","linen","nylon","polyester","power-cable","rope","thread","shoelace","silk","silk-tie","slinky","socks","spandex","suspension-bridge-cable","suit","wet-wipes","blanket","wool-yarn"]},{"slug":"weave","name":"Weaving and knitting","blurb":"Yarn is interlaced on a loom or looped on needles to make flat or tubular fabric.","uses":["airbag","backpack","towel","candle","carpet","chain-link-fence","cotton-fabric","denim","dress-shirt","flag","garden-hose","hoodie","velcro","leggings","linen","power-cable","raincoat","rope","seat-belt","shoelace","silk","silk-tie","socks","t-shirt","suit","tennis-ball","tennis-racket","underwear","blanket","sweater","zipper"]},{"slug":"sew","name":"Sewing","blurb":"Panels are stitched together. Sewing remains surprisingly manual because soft fabric is hard for robots to handle.","uses":["airbag","football","backpack","baseball","baseball-cap","towel","bike-helmet","book","curtain","down-jacket","dress-shirt","fashion-doll","felt-hat","flag","suitcase","high-heels","hiking-boots","hoodie","ice-skates","jeans","kite","leather-belt","winter-gloves","handbag","leather-shoe","wallet","leggings","mattress","office-chair","pillow","raincoat","seat-belt","silk-tie","sneaker","soccer-ball","socks","sofa","swimsuit","t-shirt","suit","tampon","teddy-bear","umbrella","underwear","blanket","sweater","zipper"]},{"slug":"dye","name":"Dyeing and bleaching","blurb":"Color is stripped out or soaked in, and then fixed with heat or chemistry so it does not wash away.","uses":["towel","carpet","cotton-fabric","denim","dress-shirt","felt-hat","hoodie","leather","leggings","seat-belt","thread","t-shirt","underwear","wood-pulp","sweater","zipper"]},{"slug":"coat","name":"Coating and plating","blurb":"A thin layer is added to a surface by dipping, spraying, rolling or electric current, to protect it or change how it looks and behaves.","uses":["guitar","action-figure","adhesive-bandage","airbag","airplane","aluminum-can","aluminum-window-frame","roof-shingle","asthma-inhaler","balloon","banknote","barbed-wire","baseball-bat","bicycle","chalk","bolt","brake-pad","bronze-statue","candy-coated-chocolate","canoe","car","car-battery","carbon-fiber","cast-iron-pan","cello","ceramic","floor-tile","chain-link-fence","chess-set","chewing-gum","chicken-nuggets","chopsticks","clear-tape","coffee-mug","coil-spring","compact-disc","condom","container-ship","corn-flakes","cotton-fabric","cotton-swab","crackers","dental-floss","toy-car","thermometer","dinner-plate","dishwasher","donut","hinge","double-glazed-window","drum-kit","drumstick","dumbbell","e-reader","electric-car","electric-guitar","electric-kettle","electric-motor","envelope","eyeglass-lens","facial-tissue","fashion-doll","faucet","felt-hat","fiberglass","insulation","fire-extinguisher","fish-sticks","fishing-rod","flute","frozen-pizza","garden-hose","gas-cylinder","gelatin-capsule","glass-bottle","golf-ball","golf-club","kitchen-countertop","hammer","hard-drive","hardwood-floor","stent","hip-implant","honey","ibuprofen","ice-skates","imitation-crab","jelly-beans","jigsaw-puzzle","key","lacquer","laminate-floor","leather-belt","led","licorice","lipstick","lithium-ion-cell","locomotive","loudspeaker","marshmallow","match","melamine-resin","microchip","microwave-oven","mirror","motorcycle","nail","neodymium-magnet","neon-sign","nitrile-glove","nonstick-pan","medal","optical-fiber","padlock","paper","paper-cup","pencil","pinball-machine","playing-cards","porcelain","potato-chips","pretzel","printed-circuit-board","raincoat","rebar","refrigerator","roof-tile","safety-pin","sailboat","sanitary-pad","saxophone","scissors","screw","needle","sheet-steel","shipping-container","snow-globe","solar-cell","sprinkles","stained-glass","water-bottle","steel-pipe","sticky-notes","pottery","subway-train","superabsorbent-polymer","suspension-bridge-cable","tennis-racket","tin-can","tinplate","tire","titanium-dioxide","toilet","trading-cards","treadmill","trumpet","turbine-blade","ukulele","thermos","vinyl-floor","vinyl-record","violin","wallpaper","washing-machine","water-heater","wet-wipes","wheelbarrow","cork-stopper","wire-rope","wooden-chair","wooden-spoon","wrench","yoga-mat"]},{"slug":"laminate","name":"Laminating and layering","blurb":"Thin sheets are bonded together so the stack has properties none of the layers has alone.","uses":["guitar","adhesive-bandage","airplane","roof-shingle","baseball","baseball-cap","basketball","board-game","book","bubble-wrap","candy-cane","canoe","cardboard","carpet","computer-keyboard","credit-card","croissant","digital-camera","diaper","double-glazed-window","dress-shirt","drum-kit","drywall","duct-tape","e-reader","envelope","jigsaw-puzzle","kitchen-sponge","kite","laminate-floor","lcd-screen","handbag","mattress","mirror","n95-mask","oled-screen","paper-bag","paper-straw","pencil","piano","pizza-box","playing-cards","plywood","pvb","printed-circuit-board","prosthetic-leg","raincoat","sailboat","sanitary-pad","satellite","shoelace","silk-tie","skateboard","ski","smartphone","smartwatch","snowboard","soccer-ball","solar-panel","staple","surfboard","suit","tennis-ball","tennis-racket","toilet-paper","vinyl-floor","wind-turbine","windshield","door"]},{"slug":"print","name":"Printing","blurb":"Ink, or a pattern of some other material, is transferred accurately onto a surface, often thousands of sheets an hour.","uses":["aluminum-can","banknote","board-game","book","bowling-ball","camera-sensor","candy-coated-chocolate","cardboard-box","compact-disc","computer-keyboard","credit-card","dartboard","globe","flag","flip-flops","frisbee","golf-ball","graphics-card","jigsaw-puzzle","laminate-floor","lcd-screen","newspaper","paper-cup","pizza-box","plastic-bag","playing-cards","porcelain","power-cable","printed-circuit-board","rubiks-cube","skateboard","ski","smartwatch","snowboard","soccer-ball","solar-cell","solid-state-drive","stained-glass","sticky-notes","syringe","t-shirt","trading-cards","umbrella","underwear","wallpaper","windshield"]},{"slug":"deposit","name":"Thin-film deposition","blurb":"Atoms or molecules settle on a surface in a vacuum or gas chamber, building up layers that can be only nanometers thick.","uses":["camera-lens","camera-sensor","compact-disc","drill-bit","e-reader","hard-drive","indium-tin-oxide","synthetic-diamond","led","memory-chip","microchip","mirror","oled-screen","optical-fiber","polysilicon","razor-blade","vinyl-record"]},{"slug":"etch","name":"Lithography and etching","blurb":"Light transfers a pattern onto a surface, and chemicals or plasma then remove everything the pattern leaves exposed.","uses":["camera-sensor","compact-disc","graphics-card","hearing-aid","stent","hip-implant","indium-tin-oxide","inkjet-printer","lcd-screen","led","memory-chip","microchip","newspaper","oled-screen","printed-circuit-board","silicon-wafer","smartwatch","television","wallpaper","wifi-router"]},{"slug":"heat-treat","name":"Heat treating","blurb":"Controlled heating and cooling rearrange a material's internal structure without changing its shape, making it harder, tougher or less brittle.","uses":["ladder","aluminum-window-frame","ball-bearing","balloon","barbed-wire","billiard-ball","bolt","button","carbon-fiber","chocolate","coil-spring","coin","condom","copper-wire","corn-flakes","drill-bit","pencil-eraser","flag","gas-cylinder","glass","glass-bottle","glass-jar","guitar-string","hammer","velcro","kitchen-knife","led-bulb","memory-chip","microchip","neodymium-magnet","nichrome","nitrile-glove","nonstick-pan","padlock","rail","razor-blade","rebar","rubber-band","rubber-boots","saw-blade","scissors","needle","sheet-steel","socks","chain","steel-beam","steel-wire","synthetic-graphite","tinplate","window-glass","windshield","wrench","yoga-mat"]},{"slug":"weld","name":"Welding and joining","blurb":"Parts are fused or bonded at a seam, with heat, solder, or adhesive, so that the joint carries the load.","uses":["aa-battery","air-conditioner","bicycle","canned-tuna","car","container-ship","thermometer","dishwasher","dumbbell","electric-car","ev-battery","electric-kettle","electric-toothbrush","eyeglass-frame","fire-extinguisher","fishing-rod","flute","fountain-pen","graphics-card","inflatable-pool-toy","jet-engine","lithium-ion-cell","locomotive","motorcycle","n95-mask","neon-sign","rocket","paper-cup","phone-charger","plastic-bag","printed-circuit-board","rail","refrigerator","saw-blade","saxophone","shipping-container","shovel","skyscraper","solar-panel","solid-state-drive","spark-plug","stained-glass","water-bottle","chain","steel-beam","steel-pipe","subway-train","tin-can","treadmill","trumpet","usb-cable","thermos","washing-machine","water-heater","wheelchair","windshield","wireless-earbuds","zip-bag"]},{"slug":"assemble","name":"Assembling","blurb":"Finished parts come together in a planned order, by hand, by robot or by both, at a station on the line.","uses":["aa-battery","guitar","action-figure","air-conditioner","air-freshener","airbag","airplane","ladder","aluminum-window-frame","football","asthma-inhaler","ball-bearing","ballpoint-pen","barbed-wire","baseball-cap","basketball","beef-jerky","bicycle","bike-helmet","blender","board-game","book","bell","drone","camera-lens","camera-sensor","candle","canned-meat","canoe","car","car-battery","car-engine","cardboard-box","ceiling-fan","cello","charcoal","chess-set","clothespin","coffee-mug","computer-keyboard","computer-mouse","container-ship","cotton-candy","cotton-fabric","cotton-swab","crayon","credit-card","cricket-bat","cultured-pearl","curtain","dartboard","denim","dental-floss","globe","toy-car","digital-camera","thermometer","dishwasher","diaper","hinge","double-glazed-window","down-jacket","dress-shirt","drum-kit","drumstick","duct-tape","dumbbell","e-reader","egg-carton","electric-car","ev-battery","electric-guitar","electric-kettle","electric-motor","electric-toothbrush","transformer","elevator","envelope","pencil-eraser","eyeglass-frame","fashion-doll","faucet","fire-extinguisher","fireworks","fishing-rod","flag","flip-flops","flute","fountain-pen","frozen-pizza","garden-hose","gas-cylinder","gelatin-capsule","gold-ring","golf-club","graphics-card","guitar-string","hairspray","hammer","hard-drive","suitcase","harmonica","headphones","hearing-aid","stent","high-heels","highlighter","hoodie","ice-skates","light-bulb","inflatable-pool-toy","inkjet-printer","jeans","jet-engine","key","kitchen-knife","kite","laptop","lcd-screen","leather-belt","handbag","leather-shoe","wallet","led","led-bulb","leggings","light-switch","lipstick","lithium-ion-cell","locomotive","loudspeaker","marker-pen","mattress","wristwatch","memory-chip","microphone","microwave-oven","popcorn","motorcycle","mouthwash","n95-mask","neodymium-magnet","neon-sign","nonstick-pan","wine-barrel","office-chair","medal","rocket","pacemaker","padlock","paper-bag","paper-cup","paper-straw","paperclip","pearl-oyster","pencil","phone-charger","piano","pinball-machine","playing-cards","power-outlet","pressure-cooker","prosthetic-leg","refrigerator","remote-control","roller-skates","rubber-band","rubber-boots","rubiks-cube","safety-pin","sailboat","sandwich-cookie","satellite","saxophone","scissors","seat-belt","shipping-container","shovel","skateboard","ski","skyscraper","smartphone","smartwatch","smoke-detector","sneaker","snow-globe","snowboard","soccer-ball","sofa","solar-panel","solder","solid-state-drive","spark-plug","stained-glass","subway-train","sunglasses","surfboard","suspension-bridge-cable","syringe","tampon","teddy-bear","television","tennis-ball","tennis-racket","tin-can","tire","toaster","toothbrush","treadmill","ukulele","umbrella","usb-cable","vacuum-cleaner","thermos","game-console","violin","volleyball","washing-machine","water-heater","wheelbarrow","wheelchair","wifi-router","wind-turbine","window-glass","wire-rope","wireless-earbuds","wooden-chair","door","yo-yo","yoga-mat","zipper"]},{"slug":"fill","name":"Filling and sealing","blurb":"Product is measured into a container and closed before anything from outside can get in.","uses":["aa-battery","acetone","adhesive","air-conditioner","air-freshener","asthma-inhaler","baby-formula","ballpoint-pen","basketball","beer","bleach","bottled-water","bourbon","cake-mix","canned-meat","canned-soup","canned-tuna","car-battery","caramel-color","caustic-soda","champagne","coconut-milk","coconut-oil","cognac","coke","cola","condensed-milk","condom","cotton-candy","cough-syrup","cream","deodorant","dice","diesel","dish-soap","double-glazed-window","down-jacket","energy-drink","ethylene-glycol","fire-extinguisher","formaldehyde","foundation-makeup","gelatin-capsule","gin","glycerin","hair-dye","hairspray","hard-cider","hazelnut-spread","highlighter","honey","hot-dog","hot-sauce","hydrochloric-acid","hydrogen-peroxide","ice-cream","light-bulb","inkjet-printer","insect-repellent","insulin","jam","salsa","jet-fuel","ketchup","kombucha","detergent","light-beer","lng","lithium-ion-cell","maple-syrup","marker-pen","mascara","mayonnaise","mead","mercury","methanol","mezcal","popcorn","mouthwash","mozzarella","vaccine","mustard","nail-polish","neon","neon-sign","nitrogen","non-alcoholic-beer","oat-milk","office-chair","rocket","oxygen","paint","p-xylene","pasteurized-milk","peanut-butter","pentane","perfume","phenol","pickles","pig-iron","pillow","port-wine","potato-chips","printer-toner","propane","propylene","prosecco","refrigerator","root-beer","rum","salami","satellite","sauerkraut","sausage","scotch","shampoo","snow-globe","soda","soy-milk","sparkling-water","steel","styrene","sunscreen","super-glue","teddy-bear","tequila","toluene","tonic-water","toothpaste","trichlorosilane","vanilla-extract","vodka","wet-wipes","whiskey","wine","yogurt"]},{"slug":"pasteurize","name":"Pasteurizing and sterilizing","blurb":"Heat, radiation or filtering kills microbes so the product stays safe on the shelf.","uses":["almond-milk","baby-formula","butter","canned-soup","canned-tuna","coconut-milk","condensed-milk","cream","cream-cheese","gelatin","ice-cream","jam","oat-milk","orange-juice","pasteurized-milk","penicillin","pickles","powdered-milk","sake","sour-cream","soy-sauce","syringe","vinegar","water","yogurt"]},{"slug":"grow","name":"Growing and culturing","blurb":"Crystals or living cells are grown under tightly controlled conditions until there is enough to harvest.","uses":["almonds","apples","yeast","baking-soda","bamboo","barley","beeswax","agave","cabbage","castor-beans","cattle","chickens","chili-pepper","cocoa-beans","coconuts","coffee-cherries","cork-bark","corn","cucumber","cultured-pearl","durum-wheat","eggs","flax","hazelnuts","honeycomb","hops","insulin","juniper-berries","koji","synthetic-diamond","led","malted-barley","matcha","vaccine","mustard-seed","natural-latex","nori","oats","oil-palm-fruit","olives","onions","oranges","peanuts","pearl-oyster","peas","penicillin","pigs","potatoes","rapeseed","raw-cotton","raw-milk","rice","rye","sake","scotch","seaweed","silicon-wafer","silk","silk-cocoons","soy-sauce","soybeans","sugar","sugar-beet","sugarcane","tea-leaves","timber","tomatoes","turbine-blade","vanilla-extract","vanilla-pods","vinegar","wheat","grapes","fleece"]},{"slug":"inspect","name":"Testing and inspecting","blurb":"Each unit, or a sample of them, is measured against a standard. Rejects are pulled before they get any more 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finished product is wrapped, boxed and palletized to survive the trip to 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