Micro-Structure Injection Compression Molding Control System’s Design And Research

The injection compression molding is a special molding means, it has great advantages in terms of forming micro-structure articles. The topic against the means of injection compression molding, on the basis of achieving the expectant requirements of the overall machine design parameters, formulating the overall program of the control system. Selecting PLC as the core controller, then design and research the control system from the hardware、software and control algorithms.The sequential injection compression was selected as the overall design process. Thermocouples、pressure sensors, electronic scale was selected according to the parameter which is to be feedback controlled, and limit switch was selected to detect digital signal. According to the points of I/O in the control system, specified PLC module type was selected. The hardware configuration was built based on STEP7. The wiring and layout diagrams of each PLC module were designed by CAD, and the process flow of the control system was designed and analyzed in detail with Visio. The control algorithm determines the control system performance in some extent. Many parameters need to be closed loop feedback controlled in the micro injection molding system. The barrel temperature and the speed of injection these two parameters were simulated and controlled by PID and adaptive fuzzy PID under different conditions. The results show that adaptive fuzzy PID controller behaves better than PID under given conditions, which indicates adaptive fuzzy PID was more suitable for micro injection compression molding control system than conventional PID in theory.