Optimization Of Injection Molding Parameter For Drop Simulation On Plastic Parts Of Electronic Products

With the development of manufacturing, plastic parts have grabbed people's eyes by its unique performances, such as small density, low production cost, high specific strength and other advantages. So it is widely used in various fields, for example, as shells of the most electronic products. Because the service condition for portable electronic products is intricacy and changeable, drop and impact is ineluctable in using. Plastic shell is the directly impact part, more and more people pay attention to the resistance capability of rupture under drop impact conditions.The traditional method gets the impact strength by practicality drop test, then gets the way to improve the quality of plastic products by experience, and to optimize the molding processing again and again. In this paper, the drop simulation and molding simulation of the digital camera have been investigated. This method overcomes the limitations for traditional method, such as high cost, long cycle. And the results of simulation are more accurate and reliable. The main contents and results of this paper as follows:Firstly, the drop simulation experiment has been carried out for the model of whole camera body by the analysis software, ANSYS/LS-DYNA. The dangerous zones of plastic shell have been found out by comparing the maximum equivalent stress and strain of different drop direction. To improve the impact strength of electronic products, the method of changing the size of model has been obtained, based on the comparison of stress in different round radius for the same drop direction.Secondly, the molding simulation of front plastic shell of digital cameras has been carried out by software, Moldflow. The location and number of gate have been analyzed. Two optimal projects have been chosen by comparing fill time, maximum cavity pressure, residual stress, the size and location of weld line and air trap. Because the warpage is one important influence factor on the stress during drop and impact, the effects of processing parameters, such as melt temperature, filling pressure, filling rate, packing pressure, packing time and cooling time, on the warpage have been investigated by taguchi test with six factors and three levels. In this taguchi test, the warpage as quality target. The influences of each factors on the warpage have been compared and the analyzed by experiment results, and the optimization processing parameters have been obtained.Thirdly, based on the experiment results of above two optimal projects, the drop simulation has been done to investigate the effects of weld 1ine on the impact strength. The drop simulation for the model of whole camera body with set microcrack in plastic shell to simulate the location and shape of weld 1ine, keep the position of microcrack in the both sides of the fall direction. The experiment result shows that the strain affected by microcrack which was composed of weld 1ine seriously. The drop simulation for the front plastic shell have been done with take the position of weld line which result from the two relatively optimal projects to the lowest location. The optimal gate project have been found out by comparing the equivalent stress, strain and the graph of speed.The investigation shows that the results of molding have been validated by drop simulation. On the other hand, the results of drop simulation can feedback to optimization design of molding processing by their combination. Finally, the optimal injection molding processing parameters have been obtained, which can improve the impact strength of electronic products.