The warpage and deformation of plastic mold injection products are very problematic. It should be handled mainly from the aspect of mold planning, and the adjustment effect of molding conditions is very limited. So, what do we do when the plastic mold injection molding products are warped and deformed?
1. When stress is deformed due to poor mold release, it can be treated by increasing the number or area of ​​pushers and setting the draft angle.
2. When the residual stress is deformed by the molding conditions, the stress can be relieved by lowering the injection pressure, increasing the mold and making the mold temperature uniform, and increasing the resin temperature or by annealing.
3. Since the cooling method is not suitable, and the cooling is not uniform or the cooling time is insufficient, the cooling method and the cooling time can be adjusted. For example, a cooling circuit can be placed as close as possible to the deformation.
4. Regarding the deformation caused by the shortening of the molding, it is necessary to correct the planning of the mold. Among them, the most important thing is to make the wall thickness of the product common. Sometimes, in the case of a last resort, the deformation of the product is measured, and the mold is trimmed in the opposite direction to be corrected. Resins with a large shortening rate are generally crystalline resins (such as polyacetal, nylon, polypropylene, polyethylene, and PET resins) than amorphous resins (such as PMMA resin, polyvinyl chloride, polystyrene, ABS resin, and The deformation of AS resin or the like is large. In addition, since the glass fiber reinforced resin has fiber orientation, the deformation is also large.