How to solve the problem of burned injection molded parts?

Injection molds often produce burns for some reason during production. Depending on the burn caused by different reasons such as mechanical, mold, or molding conditions, different solutions are taken.

1. Mechanical reasons, for example, the barrel overheats due to abnormal conditions, causing the resin to decompose at high temperature and burn into the product after injection, or the part of the nozzle and screw threads and check valve inside the material brief causes the resin to stagnate, decompose and discolor and then bring it into the product with a dark brown burn mark in the product. In this case, the nozzle, screw, and barrel should be cleaned.

2. The cause of the mold is mainly due to poor exhaust. This kind of burn usually occurs in a fixed place and is easily distinguished from the first case. In this case, care should be taken to take measures such as adding an exhaust slot back exhaust rod.

3. In the molding conditions, when the backpressure is above 300MPa, it will make the barrel part overheat and cause burn. When the screw speed is too high, it will also produce overheating, generally in the range of 40 to 90r/min is good. In the absence of an exhaust tank or when the exhaust tank is small, too high an injection speed will cause superheated gas burns.