1.Introduction Plastic extruders are also one of the types of plastic machinery. The extruders can be divided into the right angle head, the bevel head and others according to the angle between the materials flow direction of the head and the screw center line. The outer casing of the head is generally fixed on the fuselage by bolts. The mold inside the head contains a core holder, then using the nut to fix it in the inlet port of the head, and the inside of the core holder is also installed the core. The wires can pass the core and core holder since they have holes in the certer. Depending on the types of pressurization method, the extrusion process can be divided into continuous extrusion and intermittent extrusion. The equipment used in the former is a screw extruder, and the latter is a ram extruder. In this case, the screw extruder can be roughly classified into a single screw extruder and a multi-screw extruder by the number of screws.