Improvement of Plastic Injection Molding Process of Mole Trap Parts using Design of Experiments

Injection molding is a widely used mass production process. Damage due to residual stress has been observed in mole trap parts manufactured by the mass production process. Excessive deformation of the parts due to the shortened injection process caused the residual stress. Furthermore, the damage had occurred in products in which the gap in the middle of the cooled parts exceeded 101.5 mm. This study aimed to determine the process conditions in which the gap would be narrower than 101.5 mm, and the process time would be short. To explore the process conditions that restrict the deformation within the tolerance range and reduce the injection process time, the experimental design method was used. The results were used to improve the production process through regression modeling using full factorial design.