Do you know the depth of the venting groove of the injection mold? The depth of the venting groove is the key to balancing "gas discharge" and "preventing overflow". For general plastics such as PP and ABS, the depth is generally 0.02 to 0.04 millimeters. For engineering plastics such as PC and POM, the depth is generally 0.01 to 0.02 millimeters, and for thermosetting plastics, the depth is more than 0.07 millimeters. If the depth exceeds the limit, flash will occur, and if it is too shallow, air will be trapped.