Extrusion molding, also known as base model molding, involves adding powdered or granular materials from a hopper into the extruder barrel. Under the pressure and thrust of the rotating screw, the material is transported and compacted forward through friction with the barrel inner wall and screw surface. It is melted and plasticized under high temperature and pressure through external heating and friction preheating. Then, the continuously rotating screw pushes the molten material into the mold of the die, and the molten material extruded from the die mold cools and solidifies into the desired plastic product.

The extrusion process can be divided into two stages:

(1) It is to plasticize solid plastics, transforming them into a sticky flow state and, under pressure, forcing them through a mold with a special shape to become a continuous body with a cross-section matching the mold's shape.

(2) It involves using an appropriate cooling method to make the extruded material lose its plasticity and solidify into the desired product.