How to Solve the Burnt Injection Parts?
For some reasons, injection molds often get burnt during the production. With different causes of the burnt injection parts like machinery, mold or molding conditions, the solutions adopted are also different.
- For the overheating of barrel due to abnormal conditions, the resin is decomposed at high temperature, and is injected into the product after being burnt.
- Forthe stagnation of the resin caused by the threads of the nozzle and screw in the barral, check valve, etc., it is brought into the product after decompostion and discoloration, with dark brown burn marks on the product. At this time, the nozzle, screw and barrel should be cleaned.
- It is mainly due to poor exhaust. This kind of burn usually occurs in a fixed place, which can be easily distinguished from the first case. At this time, attention should be paid to measures such as adding exhaust grooves and exhaust rod.
3. Molding conditions
- When the back pressure is above 300MPa, the barrel will be overheated, causing burns.
- When the rotate speed of screw is too high, the situation of overheating will also occur. The speed generally would be great in the range of 40 ~ 90r / min.
- When there is no exhaust groove or the exhaust groove is small, if the injection speed is too high, it will cause burns of superheated gas.
If you have other opinions about the reasons for burnt injection parts or some better suggestions, please write down your comment.
Then we can have a deeper discussion about it.