Generally have been nitrided screw, in order to improve the surface hardness, i.e. to improve wear resistance. But if you ignore the cause injection molding machine screw is a long time to work at a high temperature, high pressure, high mechanical torque and high friction environments. The desired process conditions before several factors, but the loss will inevitably cause friction. Wear reason, do not seek to minimize wear and tear inevitably greatly reduce the life of the screw. In order to ensure the security and stability of the screw injection molding machine production, extending its life, we must strengthen the injection molding machine screw maintenance work, its basic contents are as follows:

　　(1) Each of plastic, has an ideal temperature range of plastics processing, barrel processing temperature should be controlled to make it close to this temperature range, the granular plastic from the hopper into the barrel, the first to reach the feed zone, plus feeding section bound to dry friction, less heat when these plastic melt unevenly, it could easily lead to the cylinder wall and screw surface wear increases, too, in the compression section and homogenizing section, if the molten plastic temporary chaos uneven , can also cause increased wear.

　　(2) speed shall be adjusted appropriately. As part of the plastic fuel enhancers, such as glass fibers, mineral or other fillers. These friction metal treatment substances are often much larger than the molten plastic. When these plastics injection molding, if the high-speed, in the raising of plastic shear force at the same time, will also make enhancer accordingly produce more torn fibers being torn fibers contain sharp end, so wear force is greatly increased. Promise of minerals at the surface of the metal high-speed taxiing, the scraping action either. So speed should not be adjusted too high.

　　(3) To verify the plastic debris. In general, under the first 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, as big as a hot ring nut clips, or even warehouse key clusters, there have been mixed into the barrel of a precedent, which is damage to screw the ineffable (of course, also damaged cylinder), so must be strictly feeding management and monitoring.

　　(4) water contained in plastic, have a certain impact on the wear surface of the screw. If the plastic will not exclude all water before injection, while the remaining water into the screw compression section, variable formed melt-kneaded in the molten plastic in the "steam particles" with high temperature and pressure, with the injection process screw propulsion, from all segments of the 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 work of plastic injection molding before drying, not only directly related to the quality of parts, but also on the screw working life. As we mentioned earlier, in order to prolong the working life of the screw, generally by flame hardening and nitriding. However, due to reinforced and filled plastics (glass fiber reinforced) plastic universal application daily, plus individual plastic itself has a strong corrosive or abrasive, they treated the screw still life is too short, in recent years developed a number of new high-tech approach to make a big difference. As outlined below: transfer plasma method, the internal hard materials such as nickel and cobalt alloy, in powder form is injected into the plasma arc, and then melted and coated cover the surface of the screw, it becomes a metallurgically bonded state than general spraying more solid. Substituted with ion nitriding gas nitriding, nitrogen and metal screws on the chemical reaction, to form a thin but uniform, hard multi-coating. Since the cost of the ion nitriding treatment is relatively cheap, while the wear life of conventional hardened tool just 2 to 3 times, it is often used for smaller diameter of the screw. In addition, ion insertion processing method, the resulting higher screw hardness and longer life.