Major breakthrough in gas-assisted injection molding technology

Professor Liu Hesheng of Nanchang University undertook the second batch of cross-century academic technology leaders training program for key disciplines in Jiangxi Province—the gas-assisted injection molding technology research and gas-assisted injection molding machine development project, which was recently hosted by Jiangxi Institute of Science and Technology. Accepted by Nanchang Science and Technology Ministry. The successful development of this project has laid a solid theoretical and experimental foundation for plastic enterprises to improve the gas-assisted injection molding process and promote the progress of injection molding technology in my country.
Experts believe that this project has taken the lead in conducting relatively mature theoretical and experimental research on gas-assisted injection molding at home and abroad, established a mathematical model of 3D thin-walled parts for gas-assisted injection molding, and independently developed a set of Windows-based gas-assisted injection molding gas. The injection control system software has strong practicability and can detect defects in the molding process in advance by simulating the injection molding process. According to the established gas-assisted injection molding experimental device, the gas-assisted extrusion was successfully realized, the gas-assisted pressure control range was large, and the relative error was small.
In addition, this project theoretically and experimentally studies the filling flow process and molding process and CAE analysis of product molding defects in the gas-assisted injection molding process, and obtains the apparent quality and intrinsic quality of the gas-assisted injection molding product. Mold structure. The regular relationship between the operating process parameters and the physical parameters was established, and then the criteria that could be used to guide the mold design, process route and operation, as well as the gas injection device and the corresponding control system, and the variable integral were proposed. Incomplete differentiation - multi-modal intelligent PID tracking control algorithm with dead zone. At the same time, on the self-developed experimental equipment, the key factor of gas-assisted molding, the formation and influence of the air-cushion film layer, was experimentally studied, and the gas-assisted extrusion of different cross-section molds was experimentally studied. Three-dimensional and non-isothermal viscoelastic numerical simulations were performed under different process parameters and different physical parameters, and various field distributions were obtained. Studies have shown that, compared with the traditional process, the application of gas-assisted technology reduces the pressure drop of the production die by 20% to 30%, and the extrusion expansion rate is reduced from 10% to 28% to less than 1%. .
At present, gas-assisted injection molding equipment and technology have been put into use in many plastic products enterprises in Jiangxi Province, and the use effect is obvious. Traditional thin-walled products can be produced by traditional injection molding machines, becoming a new generation of traditional injection molding machinery technology transformation. Experts pointed out that the research results of this project have reached the international advanced level, and the gas-assisted injection molding machine should be further improved to realize industrialization as soon as possible.