Methods to extend the service life of injection molding machine screw, please close!

Maintenance and maintenance of screw cylinder
It is found that the injection screw works in high temperature, high pressure, high mechanical torque and high friction environment for a long time. The first few factors are required by the process conditions, and the wear and tear caused by friction is inevitable. Generally, the screw is nitrided to improve the surface hardness, that is, to improve the wear resistance. However, if the cause of wear is ignored, if we do not try to reduce the wear as much as possible, the working life of the screw will be greatly reduced.

Each kind of plastic has an ideal processing temperature range, and the processing temperature of the cylinder should be controlled so that it is close to this temperature range. When the granular plastic enters the cylinder from the hopper, it will first reach the feeding section, and dry friction will inevitably appear in the feeding section. When these plastics are not heated enough and the melting is uneven, it is easy to cause the inner wall of the cylinder and the surface wear of the screw to increase. Similarly, in the compression section and the homogenization section, if the melting state of the plastic is disordered and uneven, the wear will also increase.

The speed should be adjusted properly. Because some plastics are reinforced, such as glass fiber, minerals, or other fillers. The friction of these substances on metal materials is often much greater than that of molten plastics. When injecting these plastics, if they are made with a high speed, the shear force of the plastics will be increased, and the strengthening will also result in more torn fibers, which contain sharp ends and greatly increase the wear force. When inorganic minerals glide at high speed on the metal surface, their scraping effect is not small. So the speed should not be set too high.

1. Do not start the machine when the cylinder does not reach the preset temperature. The new electric heating generally requires that the temperature reach the set value for 30 minutes before operating the screw.
2. If the shutdown is more than half an hour at a time, it is best to close the blanking port and clean the inner material of the material cylinder, and set up heat preservation
3. Avoid foreign bodies falling into the material cylinder to damage the screw and cylinder. Prevent metal fragments and sundries from falling into the hopper. If the recycled material is processed, a magnetic hopper should be added to prevent iron chips from entering the hopper.
4. When using anti-salivating, it is necessary to make sure that the plastic in the cylinder is completely melted so as not to damage the parts of the transmission system when the screw retreats.
5. Avoid screw idling, skidding and other phenomena.
6. when using new plastics, the leftovers of the cylinder should be cleaned. When using POM, PVC, PA+GF and other materials, reduce the degradation of raw materials as much as possible, and rinse clean with ABS and other nozzle materials in time after shutdown.
7. To avoid the mixing of POM and PVC into the cylinder at the same time, the reaction will occur at melting temperature, resulting in serious industrial accidents.
8. When the temperature of the molten plastic is normal but it is constantly found that the molten plastic appears black spots or discoloration, the screw rod reverse ring seat (over apron, meson) should be checked for damage.