Reduce the injection molding machine screw wear

Date：2016-06-30 09:59:47

    It is understood that the injection molding machine screw long period of time at a high temperature, high pressure, high mechanical friction and high torque work environment, several factors are needed before the process conditions, and the loss caused by friction is inevitable. Usually the injection molding machine screw has been surface-nitriding treatment, in order to improve the surface hardness, i.e. to improve wear resistance. But if you ignore the causes of wear and does not seek to minimize wear and tear, with a significant injection molding machine screw working life.
    A plastic, has a desirable plasticizing temperature processing, barrel processing temperature should be controlled to make it close to this temperature range. Granular plastic from the hopper into the barrel, will first reach the feed zone, appears dry friction in the feed zone is bound, when these plastic insufficient heat, melt unevenly, it could easily lead to the injection molding machine and injection molding machine screw barrel inner wall surface wear increase Big. Similarly, in the compression section and homogenizing section, if the molten plastic uneven disorder, also cause increased wear

    Speed ​​should be adjusted appropriately. As some plastic added enhancers, such as glass fibers, mineral or other fillers. These substances on metal friction force is often much greater than the molten plastic. When these plastics injection molding machine, if you use a high speed, then raise the plastic shear force at the same time, it will also make a corresponding strengthening produce more torn fibers being torn fibers contain sharp end, wear force so greatly increased. Inorganic minerals at the surface of the metal high-speed taxiing, the scraping action is not small. So speed should not be set too high.

    To check in addition to the plastic debris. In general, fresh plastic original purchase and there is no debris, but after transportation, weighing, drying, blending, especially renewable add back material, there may be mixed with debris. As the end of the small metal shavings, such as fever circle big nut clips, or even warehouse key clusters, mixed into the barrel have had happened, this damage is self-evident screw up (of course, will also damage the cylinder ), so you must install the magnet frame, strict feeding management and monitoring.

    Water contained in plastic, have an impact on the wear surface of the injection molding machine screw. If the plastic will not exclude all water before injection, while the remaining water into the injection molding machine screw compression zone, before they formed the molten plastic melt mixed with the high temperature pressure "steam particles", with the injection molding machine screw feeding process advance, from all segments of the injection molding machine until the screw head, these "steam particles" in the process of relief plunger expansion, like those many fine durum impurities on the wall friction produce damaging effects. In addition, certain types of plastic at high temperature and pressure, water may become a catalyst to promote the plastic cracking, corrosion of metal surfaces can produce harmful impurities. Thus, the plastic injection molding before drying work, not only on the part quality has a direct relationship, but also on the injection molding machine screw working life.

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