The quality of injection molded products needs to establish a full process control system, forming a closed loop from raw materials to finished products. Strict supplier access is required for raw material control. Each batch of raw materials is randomly inspected for melt index, tensile strength, and other indicators upon arrival at the factory. Moisture absorbing materials (such as PA/PET) need to be dried and injected within 4 hours.

Equipment and mold management are the hardware foundation, and each shift needs to check the hydraulic system and heating coil temperature, and calibrate sensor accuracy every quarter. In process control, temperature, pressure and other parameters are standardized through the Injection Molding Process Card, monitored in real-time by the MES system, and inspected by IPQC every hour for appearance and dimensions. The finished product inspection implements a system of full inspection of the first article and random inspection upon receipt. Unqualified products must be identified and isolated, and an 8D report analysis must be initiated. Through SPC statistical process control and weekly quality review, the product yield can be increased by more than 3%.