The reasons for damage to the screw barrel are:

1. The screw rotates in the barrel, and the friction  between the material and the two causes the working surface of the screw  and the barrel to wear gradually: the diameter of the screw is  gradually reduced, and the diameter of the inner hole of the barrel is  gradually increased.single screw and barrel Thus, the matching diameter gap between the screw and the barrel increases little with the gradual wear of the two. However,  since the resistance of the front head and the splitter plate of the  barrel is not changed, this increases the leakage flow when the extruded  material advances, that is, the amount of material flowing from the  diameter gap to the feed direction increases. As a result, the extruder production is reduced. This phenomenon causes the residence time of the material in the barrel to increase, causing the material to decompose. In  the case of polyethylene, the hydrogen chloride gas produced by the  decomposition enhances the corrosion of the screw and the barrel.

2. If there are fillers such as calcium carbonate and  glass fiber in the material, it can accelerate the wear of the screw  and barrel.

3. Since the material is not plasticized evenly, or  metal foreign matter is mixed into the material, the torque of the screw  is suddenly increased. This torque exceeds the strength limit of the  screw, and the screw is broken. This is an unconventional accidental damage