The extruder, barrel and screw of high and low pressure ultra-thin film blowing unit are made of high-quality alloy steel. After nitriding treatment and precision processing, they have the best hardness and corrosion resistance. The specially designed screw has high output and good plasticization. It is suitable for blowing low-density polyethylene (LDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE) and other plastic films. It is widely used in food, clothing and plastic industry Garbage bags, vest bags and other civil and industrial packaging