Causes whitening and halo of injection molded products. This is a defect due to contamination of impurities in gas or air.
The main solution:

(1) Eliminate the interference of gas, and intentionally prevent the contamination of impurities.

(2) Increase the material temperature and mold temperature, and adjust the barrel temperature in stages, but prevent the temperature from being too high to decompose.

(3) Increase the injection pressure, extend the pressure holding time, and increase the back pressure.