Research On Intelligent Control And Key Process Parameters Of Microcellular Foaming Injection Molding

Foam plastics occupied a large proportion of plastic products which has a great amount of use in various industries. Surging supercritical fluids (nitrogen or carbon dioxide) into molten material is a widely used method in manufacturing microcellular foaming products. Under the control of the relevant parameters of the injection molding machine the molten material and the supercritical fluids will be mixed into a single phase solution. Then plastic products with small bubble whose average diameter is less than 10 micrometers will be made in the mold through the instantaneous pressure drop. Surging the high-pressure supercritical fluid uniformly and steadily into the injection molding machine barrel is one key step in this forming technology. Therefore, according to the specific requirements of supercritical fluid conveying system and the special properties of supercritical fluid the key components of gas flow control will be researched. In addition, the research will lay a foundation in Intelligent control system of microcellular foaming injection molding.Firstly, the gas kick influencing the gas flow rate is studied systematically. At the same time, the formation principle of gas kick is analyzed. On the basis of this research, the gas injection system is improved.In order to make the supercritical fluid convey stably, the whole process of gas injection also is studied on the basis of gas kick research. Then the control model of the gas injection system is established which is the foundation of supercritical fluid conveying automatic control.Finally, the main process parameters which influenced the weight loss is studied in the microcellular foam injection molding experiment combined with the supercritical fluid flow type. Then the intelligent control framework with interactive interface of microcellular foam injection molding is made.