Flexible PVC Compound: PVC Dissolved Hot in Tricresyl Phosphate and Dibutyl Phthalate

Flexible PVC was Waldo Semon's discovery at B. F. Goodrich (US 1,929,453, 1933): hard PVC dissolved at high temperature in a non-volatile liquid sets on cooling into a tough, rubbery solid. His gasoline-resistant composition is 8 parts PVC, 3 parts tricresyl phosphate and 3 parts dibutyl phthalate; more plasticiser makes it softer. It can be moulded and extruded, and he names insulating electric wire and lining hose among its uses. Cutting it into pellets is our step. The picture: our diagram.