12 points to keep in mind the screw barrel of the injection molding machine
1. Match the material with the screw. Especially for corrosive materials and hard materials, such as PVC, flame retardant materials, glass fiber added materials should use professional screws, avoid ordinary screws.
2. If the corrosive material of ordinary machine is used, be sure to use a stable material such as HDPE, HIPS, etc. for the first time after use.
3. If the ordinary machine occasionally uses glass fiber, be sure to use high material temperature, low screw speed, low back pressure, remember to remember.
4. When the injection molding machine starts, it must be fully preheated by injection molding. After the barrel reaches the preset temperature, the temperature is kept below Φ60mm for 15 minutes. After the above 30 minutes, the motor is started again to start the screw-related action.
5. Regardless of the material, try not to use the lower temperature limit. For example, PC material can be produced at 250 degrees. ABS can also be used at 185 degrees, but it is not good for the screw because it requires large torque and serious wear. At the same time, if the lower limit is used, the low screw speed is used.
6. Each time the machine is stopped for more than half an hour, it is best to close the blanking port and clean the material of the barrel to set the heat preservation.
7. Avoid foreign objects falling into the barrel and damage the screw and barrel. Prevent metal fragments and debris from falling into the hopper. If the material is processed, a magnetic hopper is added to prevent iron chips from entering the barrel.
8. When using anti-mite, make sure that the plastic in the barrel is completely melted to avoid damage to the drive system parts when the screw is retracted.
9. Avoid the phenomenon of screw idling and slipping.
10. When using new plastic, the remaining material of the barrel should be cleaned. When using POM, PVC, PA+GF and other materials, try to reduce the degradation of raw materials. After shutdown, rinse with ABS and other nozzle materials.
11. Avoid mixing POM and PVC into the barrel at the same time, and react at the melting temperature to cause serious industrial accidents.
12. When the temperature of the molten plastic is normal but it is found that the molten plastic has black spots or discoloration, check whether the rubber screw back ring seat (over the apron, meson) is damaged.