Injection Molding Defects Analysis With Flow Channel Optimization And Molding Process Optimization Based On Moldflow

In the progress of science and technology, plastic products are experiencing hugedevelopment in both terms of physics and appearance with a bight future glowingahead. In recent years plastic products have been immensely applied to the areas ofautomobile, electronics, communication, transportation and aviation. As a mainprocessing for production of plastic products, the injection molding has beenincreasingly concerned. However, there are plenty of shortcomings appearing inpractice which could have seriously affected the quality and appearance of plasticproducts. How to avoid the shortcomings at the beginning and to make some progresswhen we are confronted with them has been the focal point of the injection moldingresearch.Compared with avoiding or improving the shortcomings rely on the experience,the process of the injection molding could be simulated analysed by the numericalsimulation software——Moldflow, predicting potential shortcomings, analyzing thecauses in order to raise better improving solutions, avoiding testing and modifyingmolds which could vastly improve the work efficiency. This paper takes two plasticproducts produced by some company as an example. These two products would befilled, pressurized and cooling simulated by Moldflow, then analyzing the problemsarising during the injection molding process and then give optimized scheme whichcan be tested by trying dies.As for case one, by using Moldflow software, the plastic product has been foundto be in imbalance during the filling process which could lead to short shot andover-pack. This shortcoming has been tested by trying dies. Then the main causeshave been analyzed and a solution that is to optimize channel has been raised toeliminate the very flaw. After repairing, the result of trial has shown that the solutioncan be effective which helps to eliminate the problems on short shot and over packed.And the filling has turned to be basically balanced.As for case two, serious warpage of the plastic product especially the Zdimension warpage has been found by simulated on the Moldflow. Optimization ofthe channel and DOE have been decided to use aiming at eliminate the shortcomingsafter analyzing. The new scheme can reduce the distortion of the warpage. Howeverthe distortion is still too large. By using DOE, the optimum process parameters whosewarpage can be the least was got with the discussion about filling time, melt temperature and packing pressure under different molding conditions. As shown bythe trial, the warpage distortion can be controlled acceptively under the influence ofthe optimization of channel and the process optimization.All above has shown that by using CAE, the injection filling technology, clearfile can be got which can be beneficial to get to know the physical characteristics ofthe injection filling process in each period. And theoretical basis has been providedwhich helps to find out the problems during the filling process and raise the scheme tosolve the problems. The optimization of channel and the DOE optimization haveimplications for eliminating the imbalanced filling and reducing the warpage.