Analysis of the Causes and Solutions for Swelling and Blistering of Injection-molded Products

Some plastic parts develop swelling or blisters quickly on the back of metal inserts or in particularly thick areas after being demolded during the molding process. This is caused by the expansion of gas released under the action of internal pressure when the plastic that has not been completely cooled and hardened. 

Solutions: 

1. Conduct effective cooling. Lower the mold temperature, extend the mold opening time, and reduce the drying and processing temperature of the material. 

2. Decrease the mold filling speed, shorten the molding cycle, and reduce the flow resistance. 

3. Increase the holding pressure and holding time. 

4. Improve the situation where the wall of the part is too thick or there are significant changes in thickness.