Extrusion machines are used for molding profile type products, while injection machines are used for molding complex shaped products. Injection and extrusion machines work similarly in principle. The resin, which is introduced into the machine from the feed hopper in granule form, is heated in a heating zone to make it fluid and transported to the outlet end by means of auger grooves while ensuring homogeneous mixing on the one hand.

In extruders, profiles are drawn in accordance with the mold shape with the help of pressure effect and pulling apparatus through the mold placed at the outlet end, while in injection machines, a fluidized thermoplastic resin is injected into the closed mold located right next to the outlet nozzle and cooled and hardened in the closed mold.