The screw is an important part of the injection molding machine. Its role is to transport, compact, melt, agitate and apply pressure to plastics. All of this is done by the rotation of the screw in the barrel. When the screw rotates, the plastic will rub against each other on the inner wall of the barrel, the bottom surface of the screw groove, the screw advance surface, and between the plastic and the plastic.
The forward advancement of the plastic is the result of this combination of motion, and the heat generated by the friction is also absorbed to increase the temperature of the plastic and melt the plastic. The design of the screw will directly affect the extent of these effects.