Study On Penetration Behavior And Mechanical Properties In Gas-assisted Injection Molding

Gas-assisted injection molding (GAIM) is a revolutionary injection technology, which is based on conventional injection molding (CIM). GAIM overcomes many unavoidable limitations that have been existed in CIM. So, GAIM has been accepted and developed very widely. The whole process is more complicated for the introduction of high pressure gas. With the development of technology, the form of gas injection controlled by the gas pressure control system become multiform and the process of gas operation is more and more complicated. So it is necessary to do a further study on GAIM in order to assist with the production.The purpose of this study is to understand the effect of processing parameters on gas penetration behavior, which is based on "two step" gas control manner in PPC3000, CINPRES. The gas penetration behavior included: the length of gas penetration, void areas of gas bubble and residual wall thickness (RWT). Trends of all processing parameters were further validated effectively. Therefore, some different conclusions were compared with former results, and a further analysis and explanation was made.Rib is a kind of structure which is often used in some large-scale plastic products. The gas penetration is predetermined by the setting of gas channel. With the characteristics of GAIM, ribs and gas channels are often coincident sometimes. So, the designing ideas and principles of ribs have been changed completely. By the research of all types of ribs' gas penetration behavior and mechanical performance, this study try to optimize the designs of ribs, and some proper designing principle according with the above two aspects.In addition, an in-depth study on the mechanical performances and warpage behavior of GAIM parts was made, and their mechanism and effective factors was also discussed.