existPlastic extrusion moldingIn the equipment, the plastic extruder is usually referred to as the main machine, while the subsequent equipment that is matched with it, the plastic extrusion molding machine, is called the auxiliary machine. After more than 100 years of development, plastic extruders have evolved from single screw to various models such as twin-screw, multi screw, and even no screw. The plastic extruder (host) can be matched with various plastic molding auxiliary machines such as pipes, films, rods, monofilaments, flat wires, packing belts, extruded nets, plates (sheets), profiles, granulation, cable wrapping, etc., to form various plastic extrusion molding production lines and produce various plastic products. Therefore, plastic extrusion molding machinery is one of the widely used models in the plastic processing industry, both now and in the future.The machine head is composed of an alloy steel inner sleeve and a carbon steel outer sleeve. The machine head is equipped with a forming mold, and its function is to convert the rotating plastic melt into parallel linear motion, uniformly and smoothly introduce it into the mold sleeve, and give the plastic the necessary forming pressure. Plastic is plasticized and compacted inside the barrel, and flows through a porous filter plate along a certain channel through the neck of the machine head into the forming mold. The mold core and sleeve are appropriately matched to form a circular gap with a continuously decreasing cross-section, allowing the plastic melt to form a continuous and dense tubular coating layer around the core wire. To ensure a reasonable plastic flow channel inside the machine head and eliminate dead corners where plastic accumulates, diversion sleeves are often installed. To eliminate pressure fluctuations during plastic extrusion, pressure equalization rings are also installed. The machine head is also equipped with a device for mold calibration and adjustment, which facilitates the adjustment and correction of the concentricity of the mold core and sleeve.