PTFE is made from chlorodifluoromethane, a widely used refrigerant liquid known as Freon 22. The American engineer Dr Roy Plunkett discovered that heating Freon 22 produces the gas tetrafluoroethene.
Under a pressure of about 45-50 atmospheres and in the presence of a peroxide catalyst, this gas undergoes a chemical change, and the result is PTFE in the form of a powdery resin.
Because PTFE does not properly melt, it is mixed with a suitable binder and shaped in a mould. Then it is subjected to high pressure and high temperature, and the resin particles fuse together to form a solid mass. For non-stick cookware, the PTFE powder is suspended in water to form a non-stick finish which is then sprayed on the surface and baked.