Werner & Pfleiderer was founded by Hermann Werner and Paul Pfleiderer in 1879 - whose invention, a twin-blade mixing and kneading machine quickly became the standard for the mixing of many compounds. Seeing a need for change in the early fifties, they expanded their focus to the continuously operating machines for compounding and pelletizing plastics. First came the Plastificator and now the ZSK single-stage twin-screw compounding extruder is widely used in the plastics industry. In addition to plastics, Its products are used in preparation of polyolefins, engineering plastics, masterbatches, PVC and cable compounds and powder coating. Werner & Pfleiderer is now sold under the name of Coperion which is a subsidiary of Process Equipment Group, Inc.