Screw is an important part of injection molding machine […]
Screw is an important part of injection molding machine. Its role is to transport, compress, melt, mix and apply pressure to the plastic. All of this is done by turning the screws in the barrel. When the screw rotates, the plastic will produce friction and mutual movement between the inner wall of the barrel, the bottom of the screw groove, the advancing surface of the screw edge and the plastic.
The basic working principle of the injection machine can be understood that after the plastic material is uniformly plasticized in the cylinder, the injection product is obtained by injection, liquid filling, pressure maintaining, cooling, etc.
Under the action of the screw, the granular plastic stored in the funnel moves continuously along the screw groove. Due to the combined effect of external heating and screw shearing, the plastic is continuously heated and softened, and finally a viscous flow state of the melt is formed. At the same time the melting force of the screw head pushes the screw back. By changing the screw back pressure (working oil return resistance) to adjust the screw oil return speed, change the plastic flow state in the screw groove, and finally achieve the purpose of controlling the plasticizing performance of the plastic.
The characteristics of the screw and barrel of the injection molding machine:
1. Fast anti-reverse speed capability;
2. Complete anti-return ability to keep the smallest plastic backflow phenomenon;
3. The material flows smoothly without dead ends, avoiding local shear heat, which leads to plastic deterioration;
4. Wear-resistant and corrosion-resistant;
5, can be used for a variety of plastics.
