1. The mold has poor finish, the surface of the cavity has rust, etc., and the mold is poorly exhausted.
2. The casting system of the mold is defective. The cold material well should be enlarged, the flow channel should be enlarged, the main flow channel should be polished, the runner and the gate should be polished.
3. The material temperature and mold temperature are low, and the local heating method of the gate can be used if necessary.
4. The processing pressure is too low, the speed is too slow, the injection time is insufficient, and the back pressure is insufficient, resulting in poor compactness and darkening of the surface.
5. The plastic should be fully plasticized, but the degradation of the material should be prevented, the heat should be stable, and the cooling should be sufficient, especially thick-walled.
5. Prevent cold material from entering the part, if necessary, use a self-locking spring or reduce the nozzle temperature.
6. Excessive recycled materials are used, plastic or colorant is of poor quality, mixed with water vapor or other impurities, and the quality of the lubricant used is poor.
7. The clamping force should be sufficient.
The plastic barrel factory pointed out that in order to avoid the existence of transparent defects in the plastic barrels produced, it is necessary to pay attention to the following points in the process of producing plastic barrels:
1. Improve the flow and cavity exhaust conditions.
2. Clean up possible blockages in the nozzles, runners, and gates.
3. Shorten the molding cycle. After demolding, the embossing method can be used to eliminate the silver streaks: the polystyrene is kept at 78 ° C for 15 minutes, or at 50 ° C for 1 hour, and the polycarbonate is heated to above 160 ° C for several minutes.
4. Eliminate the interference of gas and other impurities, and fully dry the plastic.
5. Reduce the material temperature, adjust the temperature of the barrel in stages, and increase the mold temperature appropriately.
6. Increase the injection pressure and reduce the injection speed.
7. Increase or decrease the pre-plastic back pressure and reduce the screw speed.