The Pressure Control Of Automatic Foam Molding Process

The foam has been widely used in the production and life, and foam moldingmachine is the important equipment in plastic industry products, but the level ofproduction of the industry is low, poor technology in China at present; automationlevel is not high. Research group and Guangzhou Feng Hua Zheng Mao packingmaterials company have a close cooperation, aiming at the existing problems ofenterprise foam molding machine was improved technology. The pressure controlsystem is the traditional switch control before the improvement of the foam moldingmachine. Although this method is simple, easy to implement, the pressure of thesteam control is very unstable and slow response speed, and noise; The overall qualityof production products is very poor.In accordance with the inadequacies existing in in the accuracy and stability ofsteam pressure control In the molding process of Foam molding machine, the Controlsystem of foam molding machine was modified, and the automation ofproduction process and Man-machine communication were improved. After analyzingthe system of non Technical improvement, the control way of fuzzy PID which cansatisfy the system requirements was suggested. The entire control system based onPLC, PLC programmable language was used to realize the fuzzy PID to control steampressure by controlling the output of the electrical proportional valve, in order toachieve the requirements of the control. the structure of the foam molding machinesand molding process were analyzed at first, and physical modeling and mathematicalmodeling of the control object were built later, then verified the reasonableness offuzzy PID control by simulink simulation in theory; next the control system wasdesigned from the hardware and software, and realized the fuzzy PID control andoptimization and improvement of the man-machine interface in the software; field experiments were made to verify the control system at last, which compared the curveeffect and the quality of products produced of before and after the technologyimprovement.The experimental results show that the control accuracy and stability of theimproved control system are better, and the quality of the foamed product is better;The control method improves the production quality..