It is a hot potato that injection plastic products warpage and deformation, mold design shall be put into main emphasis cause molding conditions adjustment is very limited. The reasons and solutions are as following:
1) Deformation of residual stress caused by molding conditions, it is a best way to eliminate stress by reducing injection pressure, improving mold temperature and make it uniformity, raising resin temperature or applying annealing method.
2) Deformation of residual stress caused by demoulding failure, the best solution is by increasing ejector pin number or area, setting up demould angle and so on.
3) As the cooling method is not appropriate, so that cooling is not uniform or cooling time is insufficient, you can adjust the cooling method and extend the cooling time. For example, try to place a cooling circuit that is close to the deformation.
4) For the deformation caused by shrinkage, it is necessary to modify the design of the mold. Among them, the most important thing is to pay attention to make the wall thickness of products consistent. Sometimes, in extreme circumstance, by measuring the deformation of the product, adjust the mold in the opposite direction.Generally, crystalline resins (such as POM, PA, PP, PE and PET, etc.) are much eaier to deform than non-crystalline resins (such as PMMA, PVC, PS, ABS resin and AS resin, etc.) . In addition, since the glass fiber-reinforced resin has a fiber orientation property, the glass fiber-reinforced resin also has a large deformation.