The high and low pressure ultra-thin film blowing machine unit extruder, barrel, and screw are all made of high-quality alloy steel, which are nitrided and precision processed, and 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, garbage bags, vest bags and other civil and industrial packaging.