2. Solid products have holes and blackening. When the solid product is formed, the injection pressure is low, and the injection speed is slow. Otherwise, the air is wrapped in the product by friction scorching under high pressure, so that there is black void in the product. Therefore, the injection pressure and the injection speed are appropriately reduced, and the void phenomenon disappears. It is also possible to check if the amount of feed is too much, and it is also advantageous to appropriately reduce the amount of feed to improve this phenomenon.
3. When the thickness of the plastic product is different, there are small bubbles in the thick part of the product, or there is a black big bubble in the extra thick part of the product. When molding several products with different shapes at the same time, it must be noted that the size of each gate should be equal to the weight of the product. Otherwise, thick products are prone to bubbles. At the same time, it is necessary to pay attention to the exhaust of the mold, and the products often left on the front mold make the exhausting more difficult, and the above phenomenon is easily generated. This phenomenon can be improved by modifying the mold or increasing the dwell time and cooling time. More importantly, when designing products, it should be avoided to have extra thick parts.