Extrusion Processing

Extrusion is the process of heating practically only TPs that may be in the shape of powders, beads, flakes, pellets, or combinations of these forms. This plastic enters the extruder's hopper. The extruder utilizes a plasticator [spiral screw that rotates within a heated barrel (cylinder)] to melt the plastic. The melted plastic is then forced through a die to produce the desired continuous product shape. Figure 5.1 shows a very simplified schematic of the extrusion process

Extrusion is the single most popular process for forming TPs. It processes over 36wt% of all plastics consumed worldwide into products such as ranging from rather simple films, sheets, rods, coatings to very complex profile forms used in window profiles, etc. Most of plastics used are PE PVC etc.