New

1, each plastic, there is an ideal plasticizing processing temperature range, should control the processing temperature of the cylinder, so that it is close to this temperature range, granular plastic from the hopper into the cylinder, the first will reach the feeding section, in the feeding section will inevitably appear dry friction. When these plastics are not heated enough, melting is uneven, it is easy to cause the inner wall of the barrel and screw surface wear and tear. Similarly, in the compression section and homogenization section, if the melting state of the plastic is disorganized and uneven, it will also cause faster wear.

2, the speed should be adjusted properly. Due to the addition of some plastic agents, such as glass fiber, minerals or other fillers, the friction of these substances on the metal material is often much larger than that of molten plastic. In the injection of these plastics, if the high speed is used, the shear force on the plastic is improved at the same time. Will also strengthen the corresponding production of more torn fibers, torn fibers contain sharp ends, so that wear force is greatly increased, inorganic minerals in the metal surface high-speed sliding, its scraping effect is not small, so the speed should not be too high.

3. 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 decreases gradually, and the diameter of the inner hole of the barrel increases gradually. In this way, the diameter gap between the screw and the barrel increases a little with the gradual wear and tear of the two. However, because the resistance of the head and the shitter plate in front of the barrel does not change, it increases the leakage flow when the extruded material advances, that is, the flow of the material increases from the diameter gap to the direction of the feed, resulting in a decrease in the production of plastic machinery. This phenomenon also increases the residence time of the material in the barrel, resulting in the decomposition of the material. If it is polyvinyl chloride, the hydrogen chloride gas generated by the decomposition strengthens the corrosion of the screw and the barrel.

4, materials such as calcium carbonate and glass fiber filling material, can accelerate the wear of screw and barrel.

5. Because the material is not plasticized evenly, or there are metal foreign bodies mixed into the material, the rotation torque force of the screw increases suddenly. This torque exceeds the strength limit of the screw, which causes the screw to break, which is a kind of unconventional accident damage.