How PVC is made

PVC is more than half chlorine by weight, which is why it starts with salt as well as oil.

stations: 6
things upstream: 21
raw sources: 9
steps from the ground: 5

The short version

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.

Combine ethylene with chlorine

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.

Goes in
Ethylene Chlorine
Crack it into vinyl chloride

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.
Polymerize it in water

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.

Goes in
Water
Strip and dry the powder

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.
Compound with additives

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.

Goes in
Pigment Plasticizer
Extrude pipe or pellets

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.

End of the linePVC Next it goes into credit card, plastic wrap, dishwasher and 16 more.

Worth repeating

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.