Assembly Line

Casting

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.

70 lines that use it

Acrylic 5 stations · 5 raw sources Aluminum 5 stations · 6 raw sources Aluminum foil 5 stations · 6 raw sources Asphalt road 6 stations · 2 raw sources Banknote 6 stations · 20 raw sources Beeswax 5 stations · 1 raw source Billiard ball 9 stations · 21 raw sources Blackboard chalk 6 stations · 9 raw sources Bowling ball 8 stations · 23 raw sources Brass 6 stations · 12 raw sources Bronze 5 stations · 6 raw sources Bronze bell 6 stations · 8 raw sources Bronze statue 7 stations · 9 raw sources Button 8 stations · 8 raw sources Candle 7 stations · 18 raw sources Car battery 6 stations · 8 raw sources Car engine 8 stations · 18 raw sources Cardboard 6 stations · 9 raw sources Cast iron pan 6 stations · 11 raw sources Ceiling fan 8 stations · 28 raw sources Chromium 6 stations · 13 raw sources Concrete 6 stations · 18 raw sources Copper wire 6 stations · 4 raw sources Crayon 7 stations · 18 raw sources Deodorant 7 stations · 23 raw sources Die-cast toy car 8 stations · 24 raw sources Digital camera 8 stations · 32 raw sources Drum kit 8 stations · 19 raw sources Dumbbell 8 stations · 20 raw sources Facial tissue 6 stations · 17 raw sources Faucet 11 stations · 23 raw sources Fiberglass 6 stations · 10 raw sources Gallium 5 stations · 4 raw sources Gold bar 6 stations · 7 raw sources Gold ring 8 stations · 12 raw sources Golf club 10 stations · 27 raw sources Indium 5 stations · 4 raw sources Lead 6 stations · 6 raw sources Licorice 6 stations · 10 raw sources Lipstick 7 stations · 13 raw sources Magnesium 5 stations · 4 raw sources Manganese 6 stations · 7 raw sources Metallurgical silicon 8 stations · 3 raw sources Motorcycle 8 stations · 29 raw sources Neodymium magnet 8 stations · 6 raw sources Nori 6 stations · 1 raw source Paper 7 stations · 7 raw sources Paraffin wax 6 stations · 3 raw sources Piano 8 stations · 15 raw sources Pig iron 6 stations · 4 raw sources Polyurethane 6 stations · 6 raw sources Potassium hydroxide 5 stations · 2 raw sources Railroad rail 9 stations · 12 raw sources Rebar 6 stations · 14 raw sources Skateboard 8 stations · 22 raw sources Snow globe 9 stations · 26 raw sources Solder 6 stations · 10 raw sources Stainless steel 7 stations · 15 raw sources Steel 6 stations · 12 raw sources Steel I-beam 6 stations · 12 raw sources Stoneware pottery 7 stations · 4 raw sources Tin 5 stations · 2 raw sources Toffee 9 stations · 25 raw sources Toilet 7 stations · 5 raw sources Toilet paper 6 stations · 9 raw sources Turbine blade 8 stations · 20 raw sources Washing machine 12 stations · 31 raw sources Wind turbine 6 stations · 25 raw sources Window glass 7 stations · 13 raw sources Zinc 6 stations · 4 raw sources

What it looks like on the line

  • Window glassFloat it on molten tin. 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.
  • Bowling ballPour the urethane shell. 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.
  • ToffeeOr deposit into molds. 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.
  • ConcretePour it around the steel. 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.
  • LicoricePour into starch molds. 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.
  • Billiard ballPour into molds. 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.
  • Car enginePour the engine block. 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.
  • Metallurgical siliconCast into molds. Refined silicon is poured into molds, then cooled until solid.
  • Steel I-beamCast a bloom. 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.
  • Car batteryCast the grids. 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.
  • Die-cast toy carPump it into the die. 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.
  • LipstickPour into molds. Hot liquid goes into a metal mold with many stick-shaped cavities.