1. Each plastic has an ideal plasticizing temperature processing range. The processing temperature of the wire drawing machine barrel should be controlled to be close to this temperature range. When granular plastics enter the barrel from the hopper, they will first reach the feeding section. Dry friction will inevitably occur in the feeding section. When these plastics are not heated enough and melt unevenly, it will easily cause increased wear on the inner wall of the barrel and the surface of the screw. Similarly, in the compression section and the homogenization section, if the molten state of the plastic is disordered and uneven, it will also cause accelerated wear.
2. The speed should be adjusted properly. Because some plastics have reinforcements such as fiberglass, minerals or other fillers. The friction force of these substances on metal materials is often much greater than that of molten plastic. When injecting these plastics, if a high speed is used, while increasing the shear force on the plastic, the reinforcement will also produce more shredded fibers. The shredded fibers contain sharp ends, causing wear and tear. Strength is greatly increased. When inorganic minerals slide on the metal surface at high speed, their scraping effect is not small. So the speed is not directly adjusted too high.
3. The screw rotates in the barrel, and the friction between the material and the two causes the working surfaces of the screw and barrel to gradually wear: the diameter of the screw gradually decreases, and the diameter of the inner hole of the barrel gradually increases. In this way, the matching diameter gap between the screw and the barrel increases little by little with the gradual wear of the two. However, since the resistance of the machine head and the splitter plate in front of the barrel has not changed, this increases the leakage flow of the extruded material when it advances, that is, the flow of the material from anywhere in the diameter to the feeding direction increases. As a result, plastic machinery production volume decreased. This phenomenon increases the residence time of the material in the barrel, causing the material to decompose. If it is polyethylene oxide, the hydrogen chloride gas produced by decomposition will intensify the corrosion of the screw and barrel.
4. If there are fillers such as calcium carbonate and glass fiber in the material, it can accelerate the wear of the screw and barrel.
5. Because the material is not plasticized evenly, or metal foreign matter is mixed into the material, the screw rotation torque suddenly increases abnormally. This torque exceeds the limit strength of the screw, causing the screw to twist and break. This is an unconventional accidental damage. .
