A Concurrent-Engineering Approach Toward the Online Adaptive Control of Injection Molding Process

Injection molding is the most effective process to produce plastic parts of complex shape to the highest precision at the lowest cost. Considerable progress has been made over the last two decades in modeling and simulation of the molding dynamics. However, due to complex material properties and other uncontrollable disturbances, consistency of part quality cannot be assured in production. This paper presents a new approach to the problem. Based on the concept of Concurrent Engineering, we make full use of the power of simulation for the design of the part, the mold, and setting up process control parameters automatically. The control system consists of feed-fotward and feedback loops with numerous sensors in each loop. With an online PC and a smart part-quality sensor, the system can control the variation of part weight many times better than existing methods.