Plasticization Of Trunk Lid Plastic And Molding Parameter Optimization

So far, the application in various automobile products of the method which is thelightweight of autobody to reduce excess material from the original parts is close toperfection. So it will be very hard to reduce vehicle weight through this kind of method. Thisarticle focuses on the replace of material, using plastic to replace steel. The advantages ofplastic are the abundant resources and superior performance. The trunk lid outer panel is agood example which can achieve the goal of lightweight through the using of glass fiberreinforced PET. With the theory of thin plate stiffness, the thickness of the redesigned plasticboard can be3mm. Then the overall quality was reduced by24.1%.The characteristics of the redesigned trunk lid outer pane are that the superficial area ofparts is large and the thickness is small. According to the above characteristics and thecharacteristics of plastic forming, injection molding is chosen as the forming way of trunklid outer pane. However, the main defects which can affect the injection molding parts is theamount of part warpage. And the amount of part warpage has close relationship with avariety of process parameters. The melt temperature, mold temperature, injection time anddwell time have the greatest influence. The crafts parameter of PET injection molding is nota certain value or the given numerical range suitable for injection molding. In order to avoidthe test for many times, finding the combination of the minimum crafts parameter and usingMoldflow simulate plastic injection process can help to get the amount of warping ofinjection molding. In the paper, the research emphasize how to find the optimal parametercombination in the range of the above given parameters. With the orthogonal experimentdesign method to design25sets of parameters conbination and the Moldflow to simulate25sets of injection molding process, one of the minimum amount of warping injectionparameters of the25sets has been found out. In the design of orthogonal experiment, if the parameter range can be refined, thesmaller warp parameter combination will be got. The disadvantage is that the Moldflowinjection molding simulation needs long time. The BP neural network has great advantage inthe approximation of nonlinear mapping, and the training time is short. With the BP neuralnetwork simulation of the injection molding parameters and Warpage nonlinear mapping andthe refinement of the parameters, the minimum parameter combination can be found out.Comparing with the recommended injection parameter, the warpage has reduced by27%. Itreduces not only the test cost but also the warpage. It also greatly reduces the time ofparameter optimization.