Analysis And Optimization Of Injection Molding Process Of Complex Surface Based On Moldflow

The development of mold technology is closely related to the application of the new products and new technologies,such as automobiles,household appliances,electronics,chemical industry and so on.In the process of injection molding,plastic melt is injected into the mold cavity at high pressure and high speed,and then be cooled to form a plastic product which is consistent with the shape of the mold cavity.Injection molding can produce various plastic products with complex geometry.However,injection molding is a complex process with characteristic of multi variable,nonlinear,periodic and non-stationary.Therefore,it will be easy to produce defects such as short shot,flash,shrinkmarks,cavitation,weld line,warp deformation.Especially,the injection molding process of plastic parts with complex surfaces is more complex and changeable,and the number of data points on the surface is huge and there is no fixed rule.In the past,it was difficult to meet the quality requirements by the experience of mold design.It is a technical problem in the design and manufacture of injection mold.In recent years,with the development of computer aided technology,the technologies of CAD/CAE/CAM have gradually been applied to the mold design and manufacturing process.Through the building of physical and mathematical model on polymer molding,the injection process and the pressure and cooling process are simulated.The stress of the product and die are calculated and analyzed.The warpage will be predicted.The computer numerical test is used to represent the traditional model test and repair process.The product development cycle will be greatly shortened,and the production costs will also be reduced.The extensive application of CAD\CAE\CAM technology has promoted the development of injection mold industry.Firstly,the CAE technology of injection mold design and application of MOLDFLOW software were introduced in this paper.With the case of toy car shell,some main problems existing in the free surface of injection molding were analyzed.The key problems to be solved in the design were proposed.Secondly,the basic content of injection molding is briefly introduced.The influence of parameters such as temperature,pressure and time on injection molding is explained,and the causes of plastic parts defects are analyzed.This paper focuses on the overall design of the injection mould on the toy car shell.The CAE analysis of injection molding process based on Moldflow was carried out.The optimum gate location and cooling mode of the plastic parts were determined by analyzing and comparing the different gate number of gating system.Through the flow simulation of injection molding process,the filling,pressure drop and weld line of injection molding are predicted,and the reasonable injection molding process parameters are obtained,which can shorten the design and tryout time,and reduce the manufacturing cost.The results have great reference value for the rapid optimization design and manufacture of injection mold.