Simulation Analysis And Process Optimization Of Microcellular Injection Molding

In recent years,oil resources are running out of,which leads to a high price of polymer raw material in such competitive society.Microcellular injection molding technology is becoming more and more crucial in many fields,it not only can obviously reduce weight keeping the mechanical properties,but also can achieve continuous production easily.Microcellular injection molding technology started late in china without the patent of the related equipment,which enhance the price of experiment.With the development of computer,n?merical simulation has become a significant tool for product design.The study based on microcellular injection molding simulation has already come to maturity,but there is a lack of systematic knowledge of the bubble distribution and the process mechanism of microcellular injection molding products.The morphological structure of micro-cells can be controlled by optimizing the processing parameters.The improper processing parameters make performance worse,and the research to optimize the processing parameters is sightless.There is less research focusing on the molding quality of the parts,overlook service quality of the parts.According to the issues mentioned above,the main research work has been listed as followed:Firstly,based on classical nucleation model,finite element software Moldflow was employed to investigate the influence of the gas foam type for bubble distribution and the distribution of bubble for the standard tensile in different direction,then we got the bubble position which can describe the distribution of bubble for the standard tensile,in the end,we predict tensile modulus in RVE method;Secondary,orthogonal experiment was designed to investigate the influence of processing parameters on the distribution of micro-cells and mechanical properties of the part.We select some processing parameters which effect the distribution of micro-cells and mechanical properties of the part greatly.The simulation results were analyzed in S/N to study the relationship between them,and optimize the processing parameters.Thirdly,the sequential optimization algorithm based on the Kriging surrogate model and expected improvement sampling criterions are employed to optimize molding quality of the part.Result shows the warpage decreased by 26.2%,and the overall molding quality of the part decreased by 46.4 %Finally,import the result of Moldflow into Abaqus for structural analysis,which includes the model mesh,boundary conditions,material properties,warpage,and residual stress results,then an entire analysis from molding to service is built for the service quality issue.Result shows that the optimization method can decrease the service stress by 24%.