注射系统的作用：注射系统是注塑机最主要的组成部分之一，一般有柱塞式、螺杆式、螺杆预塑柱塞注射式3种主要形式。目前应用最广泛的是螺杆式。其作用是，在注塑料机的一个循环中，能在规定的时间内将一定数量的塑料加热塑化后，在一定的压力和速度下，通过螺杆将熔融塑料注入模具型腔中。注射结束后，对注射到模腔中的熔料保持定型。
Function of injection system: Injection system is one of the most important components of injection molding machine. Generally, there are three main forms: plunger type, screw type and screw pre-plastic plunger injection type. At present, screw type is the most widely used. Its function is to heat and plasticize a certain number of plastics in a specified time in a cycle of the injection machine, and inject molten plastics into the mould cavity through screw under a certain pressure and speed. After the injection, the melt injected into the cavity is kept in shape.