What are the reasons for the cracking of injection parts?
In the process of injection molding, the phenomenon of cracking of injection parts is mainly caused by the following reasons:
1. Processing
Excessive processing pressure of the injection molding machine, fast injection speed, long injection, and holding time will cause internal stress in the product, which will lead to cracking.
Solution:
1. Properly adjust the mold temperature to make the product easy to demolding; 2. appropriately use a mold release agent, and always pay attention to impurities in the mold cavity; 3. use annealing heat treatment to eliminate the internal stress of the product and avoid the occurrence of cracking.
2. Mold structure
The number of ejector pins in the mold ejection system should be sufficient, and the cavity surface must be smooth enough to effectively prevent internal stress.
Solution
1. Design reasonable wall thickness for the injection-molded product, and use arc structure to avoid internal stress; 2. use metal inserts as little as possible to prevent different shrinkage of different material; 3. set appropriate runner size to ensure that the gate can be cooled quickly and demolding in time.
3. Raw material
The percentage of recycled materials is too large, resulting in low strength of injection parts.
4. Technology
Choose the appropriate process and set reasonable material temperature and other properties according to the material.
