Causes of Damage to Screw and Barrel of Plastic Pipe Extrusion

Causes of damage to screw and barrel of plastic pipe extrusion
1, the screw rotation in the barrel, the material and the friction between the two, so that the screw and the barrel of the working surface gradually wear: screw diameter gradually reduced, the barrel of the hole diameter gradually increased. In this way, the screw and the barrel with the diameter of the gap, with the gradual wear and tear of the two slightly increased. However, since the resistance of the head and the manifold in front of the barrel does not change, this increases the leakage flow when the extruded material is advanced, i.e., the flow of material from the diameter gap to the feed direction. As a result, the extruder production is reduced. This phenomenon also makes the material in the barrel to increase the residence time, resulting in material decomposition. If it is polyethylene, the decomposition of hydrogen chloride gas to strengthen the corrosion of the screw and barrel.
2, if the material such as calcium carbonate and glass fiber filler, can speed up the screw and barrel wear.
3, because the material is not plasticized evenly, or a metal foreign body mixed with the material, so that the screw rotation torque force suddenly increased, this torque exceeds the screw strength limit, the screw twist. This is an unconventional accident damage.