Once the plastic material is injected into the mold, it will shrink immediately. Therefore, when designing the mold, the optimal gate location, diameter, cycle time, and smooth flow should be selected. tract to avoid delamination and voids.  

Typically, the part is removed from the mold and cooled to room temperature, and then the shrinkage after molding is done. Factors such as the complex shape of the part and the change in shrinkage rate associated with the size of the part can cause internal stresses during the cooling process. Internal stresses can cause buckling deformation. The annealing process after molding can reduce internal stresses and avoid warping deformation.