Black spots of common problems in injection molding
What is a black spot? Black spot refers to the black spots or stripes on the molded products.
Causes of black spots on injection molded parts:
1. Resin decomposition
As plastic is a chemical, it will decompose gradually when it is heated above the melting point. The higher the temperature, the longer the time and the faster the decomposition. In addition, there are some areas in the barrel that are easy to retain resin, such as check check valve and thread. The […]