Numerical Analysis And Optimization Of Injection Molding Process For Complex Plastic Products

As the improvement of modern life and the high-speed development of modern technology, more and more complex plastic parts are used, especially in the industry of microelectronics, MEMS, automotive and home applications. People become more and more keen on quality, like high accuracy of the dimension, ultra-thin thickness, more complicated appearance and highly-integrated performance. Thus, the output production, quality and process parameters of plastic parts turn to be crucial. But we are clearly aware of that to ensure high quality of plastic parts there are three most important key points, amazing part design, perfect-designed mold and optimal process parameters, each of which are indispensible.Aiming at solving the main injection molding defects of plastic coffee barrel support, RHCM technology and orthogonal test design method were introduced to realize the optimization design of mold structure and process parameters.Based on common injection molding process and original mold structure, in allusion to different gate location and runner system, melt flow in cavity was simulated by Moldflow to optimize the structure of gating system. With qualitative analysis of weld mark and sink mark, the apparent quality of the plastic parts was evaluated.It is concluded that obtaining constant pressure drop after linear and pressure curve as the optimal pressure maintaining plan through different pressure maintaining project simulation on the coffee barrel support product design, which can not only obtain a uniform cavity pressure distribution, but also gain high quality of products. Combined with the pressure of optimal scheme flow end’s cavity pressure curve, the packing curve was optimized in accuracy.To achieve rapid heat and cold cycle of RHCM, the simulation was divided into two steps, based on different cooling system design. We analyzed weld defect and cooling effect to optimize cooling system design. It was indicated that RHCM technology can not only greatly improve the flow melt, reduce weld mark, but also improve the cooling effect, which has great advantage on eliminating weld line.Process parameters would affect quality of molding products, and the significantly influencing diagram on products was obtained through the orthogonal test design analysis, regarding to melt temperature, pakcing pressure and time, cooling time. Influence factors of weldline length, shrinkage mark index and volume shrinkage are as evaluation index. Combined with analysis of the comprehensive comparison of the test and the simulation results of the original process, the optimal process parameters combination was concluded.Based on injection molding CAE technology and RHCM technology, the optimal design methods of injection mold structure and forming process is put forward in the paper.