PVC generally needs to be modified granulation first. After being made into particles by a plastic screw extruder, it has fuller plasticization and easier processing, especially for injection-molded products. A screw extruder is one of the most important pieces of equipment for plastic molding processing, it adopts external power transfer and heat transfer of external heating elements to carry out solid transport, compaction, melting, shear mixing, and extrusion. The screw extruder occupies an important position as either a plastic pelletizing machine or a molding processing machine. Strictly speaking, PVC products with special requirements and PVC-modified formulations are customized according to customer requirements.