There are several kinds of bubbles, the phenomenon is different, and the reasons are different. The description is as follows.
1. Thicker products, the surface is fat and bulging, there are bubbles at the sawing section, the reasons may be:
(1) The injection speed is too fast, entraps the air, cannot be eliminated, and forms bubbles.
(2) If the amount of feed is too much or too little, and the injection pressure is too high, this phenomenon will also occur. If the feed amount is properly adjusted, this phenomenon will be improved.
(3) The cooling time is too short (especially thick-walled products), and the solution can be cooled by using cold water and cold stamping die outside the machine.
(4) There is a phenomenon of decomposition of black lines in the product, which is formed due to excessive temperature. If the situation is not serious, the temperature can be lowered appropriately. If the entire barrel is disassembled, it must be removed by car.
(5) The phenomenon that the mold inlet is too small and the exhaust gas is poor.