Research On The Plastic Thin-wall Parts Injection Molding Surface Quality Control

The plastic thin -wall parts is defined as the plastic injection parts which wall isbelow two millimeters. Compared with the normal plastic injection parts, thin-wallparts has some advantage, such as save materials, reduce costs, enhance productivity,more slighter, etc. Furthermore, because of the character in designing and injecting,the injection characters of the plastic thin-wall parts have in order to do in different,including the materials, mould and equipments. Moreover, compared with thenormal injected parts, the injection technique of the thin-wall parts show morecomplex and more difficulty to control. The thin-wall parts are easily injected withthe surface defects, such as the shot injection, flow injection, wrapage, fusion marks,crack etc. How to control such defects and get better quality products is the mainaim of this problem researched. And the core of this study is to build the "plasticthin-wall injected parts' surface quality control system"(PPSQCS), coming to thecapability of forecast the usual defects of the thin-wall parts.During the research of this paper, various kinds of defects of thin-wall injectedparts, including shot injection, flow injection, wrapage, fusion marks and crack, hadbeen analyzed and summarized in the first phase. In this phase, the main goal is todraw the conclusion of what defects will be lead to and which kinds of injectionparameters will influence them. According to different kinds of surface defectsquality of the thin-wall parts, "the plastic thin-wall injection parts surface qualitycontrol model" (PPSQCM) was established. In this phase, various kinds oftechnology or method have been used, including Design of Experience (DOE), CAEtechnology (Moldflow Plastic Insight, MPI), Response Surface Methodology (RSM),as well as analysis of variance method (ANOVA), etc. While the optimizationstrategy introduced in this paper is genetic algorithm (GA). During the second stagecarried out, because the traditional genetic algorithm has contradiction between in theglobal research and the local research, as well as the shortage in local research, inforecasting the thin-wall parts injecting parameters, the genetic algorithm optimized(GAO) has been created according to the shortage of traditional genetic algorithm. While in "the plastic thin-wall parts surface quality control system" (PPSQCS),exploitation phase, the engineering algorithm language Matlab was used to finishedthe all stage of forecasting and the forecasting result viewed, moreover, get to theinteraction between individual and computer friendly and facility. Using theinterface technology between Matlab language and visual C++, the oriented to objectlanguage, this study reached the independence of the plastic thin-wall parts surfacequality control system.Finally, two cases, one kind of mobile phone shell and one kind of telecontroldevice shell used on insurance door, were introduced to test PPSQCS. The formerwas tested in numerical simulation and the later was used in practice. The resultshowed it is feasible and reasonable.