Extrusion molding, also known as basic mold molding, involves adding powdered or granular materials into the extruder barrel through a hopper. Under the pressure and thrust of the rotating screw, the materials are conveyed and compacted forward through the friction between the barrel wall and the screw surface. After external heating and friction preheating, the materials melt and plasticize under high temperature and pressure. Then, the continuously rotating screw pushes the molten material into the mold of the die, and the molten material extruded from the die cools and shapes into the required plastic products.

The extrusion process can be divided into two stages:

(1) It is to plasticize solid plastics, transforming them into a sticky fluid state and, under pressure, forcing them through a special-shaped die to form a continuous body with a cross-section identical to the die shape.

(2) Utilizes an appropriate cooling method to transform the extruded material from a plastic state to a solid state, resulting in the desired product.