Injection-molded part burn, how to fix it?
The injection mold often produces burns during production due to some reasons. According to the burn caused by different reasons such as machinery, mold or forming conditions, the solution is also different.
1. Mechanical reasons, for example, due to abnormal conditions caused by overheating of the barrel, the resin decomposition at high temperature, burn after injection into the product, or due to the nozzle and screw thread, check valve and other parts caused by resin stagnation, decomposition and discoloration into the product, with black brown burn in the product. At this time, the nozzle, screw and barrel should be cleaned up.
2. The reason for the mold, mainly because of poor exhaust. This kind of burn generally occurs in a fixed place, which is easy to distinguish from the first case. At this time, attention should be paid to measures such as adding exhaust tank and reversing exhaust rod.
3. In terms of forming conditions, when the back pressure is above 300MPa, it will overheat the barrel part and cause burns. When the screw speed is too high, it will also produce overheating, generally in the range of 40 ~ 90r/min. When there is no exhaust tank or the exhaust tank is small, the injection speed is too high will cause superheated gas burns.