The injection system is one of the most important components of the injection molding machine. Generally, there are three main forms: plunger type, screw type, and screw pre-plastic plunger injection type. The most widely used is the screw type. Its function is that in a cycle of the injection molding machine, after a certain amount of plastic can be heated and plasticized within a specified time, the molten plastic can be injected into the mold cavity through a screw under a certain pressure and speed. After the injection is completed, the shape of the molten material injected into the mold cavity is maintained.