The material of the extruder screw must have the performances of high mechanical strength, withstanding huge torque and non deformation under high temperature and pressure.
The reason is that the extruder screw elements rotate in the barrel under high temperature, high pressure and large torque. Because it must force the material to move forward during rotation, and it also has to withstand strong friction and corrosion of plastic decomposition gas erosion, the extruder screw must have the advantages in these performances.
During the rotation of the extruder screw, it is mainly used to shear and plasticize the plastic and push the plastic forward, which will bear huge shear stress and friction. Due to long-term work under harsh conditions, the extruder screw edges are worn and become smaller, and the gap with the barrel increases, which will cause the plastic extrusion volume to decrease. In severe cases, plastic reflux will occur, and the plasticizing effect will be reduced, and crystal grains will appear. Finally, the phenomenon of serious decline in production capacity.