Numerical Simulationresearch Of Micro-Injection Moldingsimulation

Owing to the increasing demand of micro products along with the development of micro electrimechnical system technology,micro products by traditional microfabrication technology can hardly meet with the requirement of microsystem.Nevertheless,micro products by micro injection molding technology have become an important development temand because of its efficiency,stable quality and so on.The traditional theory of injection molding cannot be used to the fabrication of micro injection molding completely.The influence by some parameters,between micro injection molding and tradional injection molding,is not same.So,need to create a new theory,at the particularity of micro injection molding.First the current research of micro injection molding at home and abroad is introduced in this thesis,then according to the basic theory and process of conventional injection molding, using the CAE software,numerical simulation research of the injection molding characteristic for micro thin-wall plastic parts are put forward,then analyze the warpage and shrinkage to optimize the parameter for micro-gear.This paper can offer the theory guidance for the actual production process parameter.The principal contents studied in this thesis are as follows:1) The micro thin-wall plastic injection processes of simplified shell part is simulated,selecting two materials:POM,PMMA,and selecting three size.The effects of process parameters(melt temperature,mold temperature,injection pressure,injection rate) on molding characteristic of micro thin-wall plastic parts are discussed by single factor method,with dimension reduction, compare the significance of each factors.2) The micro-gear plastic injection processes are simulated,selecting one material:PP.The effects of process parameters(melt temperature,mold temperature,injection rate,holding pressure,holding time,cooling time),The warpage and shrinkage date are analyzed using ANOVA.The results are used to compare the significance of each factors,and obtain the optimum set of factors.3) Calculate the contributor and variance of the six parameters to warpage and shrinkage of the micro-gear.Compared among the six parameters,holding pressure is the most important to stable quality of micro-gear.4) Optimize the group of the six parameters,by using the optimizion of orthogonal experiment, and validate by simulation.The results of simulation are the best among the 18 groups.