Plastic extruder is to continuously extrude plastics from the head section by virtue of the pressure of screw rotation after plasticizing plastics into a uniform melt. Plastic extruder can form production lines with different plastic molding auxiliary machines to produce pipes, rods, wires, boards, films, wire and cable coatings etc. and to be used for plastic mixing, plasticizing granulation, coloring, blending and other processes. It can be divided into single-screw, twin-screw and multi-screw extruders according to the number of screws. Products made from plastic extruders are widely used in agriculture, building, petrochemical engineering, machinery manufacturing, medical equipment, automobile, electronics, aerospace and other industries.