Extrusion is used for the production of conventional commercial plastic packaging.
This process uses one or two rotating screws fitted in a barrel in order to progressively increase the pressure and push forward and mix the ingredients required to manufacture the commercial polymer through a die where expansion may take place (Nur Hanani, Beatty, Roos, Morris, & Kerry, 2012). Extrusion is often preferred to casting as the method of fabricating films because the throughput of the process is faster and less energy is required for the removal of water (Fishman, Coffin, Konstance, & Onwulata, 2000).