China's gas injection molding technology has achieved major breakthrough in R & D

Prof. Liu Hesheng of Nanchang University undertakes the second batch of academic and technological leaders training programs for the major disciplines in Jiangxi Province – gas-assisted injection molding technology research and gas-assisted injection molding machine development projects. He was presided over by Jiangxi Science and Technology Department in Nanchang recently. acceptance. The successful development of this project has laid a solid theoretical and experimental foundation for promoting the progress of injection molding technology in China and improving the gas-assisted injection molding process for plastic products enterprises.

Experts believe that the project took the lead in the domestic and foreign gas-assisted injection molding for more theoretical and experimental research, established a three-dimensional thin-walled parts of the gas injection molding process mathematical model of filling, self-developed a set of Windows-based platform Gas-injection injection molding gas injection control system software has strong practicability. It can discover the defects of the molding process in advance by simulating the injection molding process. Based on the gas-assisted injection molding experimental device established in this way, gas-assisted extrusion was successfully achieved, and the range of gas assisted pressure control was large and the relative error was small.

The project carried out theoretical and experimental research on the CAE analysis of mold filling flow process during gas assist injection molding and the theoretical and experimental research on molding process and product formation defects, and obtained the apparent and intrinsic quality of gas assisted injection molding products and gas assisted injection mold structure and operation. The relationship between the process parameters and the physical properties of the raw materials, and then put forward guidelines that can be used to guide the design of the mold, process route formulation and operation, and the development of the gas injection device and the corresponding control system, proposed variable integration - not complete Differential-Multi-modal Intelligent PID Tracking Control Algorithm with Dead Zone. At the same time, on the independently developed experimental equipment, an experimental study was conducted on the formation and impact of the air-cushion film layer, a key factor in gas-assisted molding, and the gas assisted extrusion of different cross-section dies under different process parameters and different physical property parameters. Three-dimensional, non-isothermal viscoelastic numerical simulations were performed and various field quantities were obtained. Studies have shown that compared with the traditional process, the use of the gas-assisted technology, the production of die pressure drop by 20% to 30%, extrusion swelling rate decreased from 10% to 28% to 1% or less.

At present, the gas-assisted injection molding device and technology have been put into operation in a number of plastic product enterprises in Jiangxi Province. The use effect is obvious. It can produce thin-walled products with complex processes using traditional injection molding machines and become a replacement product of traditional injection molding machine technology transformation. . Experts pointed out that the research results of the project have reached the international advanced level, and gas-assisted injection molding machines should be further improved to enable industrialization as soon as possible.