How to solve injection part burn?

Injection molds are often burned due to some reasons during production. According to the burn caused by different reasons such as machinery, mold, or molding conditions, the solutions are also different.

1. Mechanical reasons, such as overheating of the barrel due to abnormal conditions, high-temperature decomposition of the resin, injection into the product afterburn, or stagnation of the resin due to the nozzle in the material, the thread of the screw, the check valve, etc. After decomposing and discoloring, it is brought into the product, and there are dark brown burn marks in the product. At this time, the nozzle, screw, and barrel should be cleaned.

2. The reason for the mold is mainly due to poor exhaust. This kind of burn generally occurs in a fixed place and is easy to distinguish from the first case. At this time, measures such as adding an exhaust slot and an anti-exhaust rod should be taken.

3. In terms of molding conditions, when the backpressure is above 300MPa, the barrel part will be overheated, causing burns. When the screw speed is too high, overheating will also occur, generally within the range of 40 ~ 90r/min. When there is no exhaust slot or the exhaust slot is small, the injection speed is too high, which will cause burns of the superheated gas.