The cylinder and screw is made of high-quality alloy steel through nitriding, which to make sure the hardness and corrosion resistance. This machine is suitable for making shopping bags film. The winder adopts single or double taking. It is controlled by torque motor. It can keep suitable tension. It is easily to change the rolls. The high and low-pressure polyethylene dual-purpose film blowing machine unit can be used to blow various plastic films such as low-density polyethylene (LDPE), high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE). The plastic films can be widely used for civil and industrial packaging such as food, fruits, apparel, textiles, trash bags and vest bags.