Screw barrel how to reduce wear and improve the use of screw barrel
Injection molding machine screw is a long time at high pressure, high temperature, high mechanical torque and high-friction environment for work. Process conditions in front of several factors is required, but the friction caused by wear and tear is inevitable. Have been generally screw nitride surface treatment to improve the surface hardness, wear resistance is increased. But if you ignore the reasons that cause wear and tear, do not try to minimize the wear and tear, is bound to greatly reduce the working life of the screw.
The following 2 points to introduce the reasons and causes the screw to reduce the wear and tear means wear and tear
1, each of plastic raw materials, has an ideal temperature range of plastics processing, it should control the barrel temperature processing, so close to this temperature range. Granular plastic from the hopper into the barrel, will first reach the feed zone in the feed zone is bound to dry friction, less heat when these plastics, melt unevenly, it is easy to cause cylinder wall and screw surface wear increases; the same in the compression section and all of segment, if the molten plastic disorder inequality, can also cause increased wear and tear.
2, speed should be adjusted properly. Because some plastics have enhancer, such as glass fiber, minerals, or other filler. These substances on metal friction is often much greater than the molten plastic. These plastic injection molding, if the high-speed, then raise the plastic shear force, but also will be enhanced accordingly to produce more pieces of fiber, the fiber was shredded with a sharp end, so wear power is greatly increased. Inorganic minerals in the metal surface of the high-speed taxiing, the scraping effect is not small. So speed is not too high.