Application Of CAE In The Design Of Runner System For Thin Plastic Shell Injection Molding

Recently,with the developing of computer technology in software and hardware,injection mold CAE technology has already achieved tremendous development.Mold designer and producer can utilize it to modify the design scheme and technological condition in order to avoid short of design experience and desing error bring kickback,consequently reduce the cycle of mold design and produce,to cut down production costs,to improve the design and manufacturing level of injection mold and producter quality.In this paper,firstly the thin-wall injection technology is introduced summarily,at the same time the development situation of injection plastic mold CAE technology and the study significance are presented.Secondly,flow simulation theory of injection plastic mold is introduced,combining the characteristic of thin-wall injection molding.Based on pilot study on plastic viscosity model,rheological theory and numerical method,the math model of fusant flow on the process of thin-wall injection molding is established,and the math model is solved with the method of finite element/finite difference,then get the numerical calculate flow of filling process.Application of design of runner system in the injection molding based on CAE technology and flow simulation is studied,and theoretical design method concerning runner system is expounded,then optimization design flow of runner and gate is brought forward.At last,the flow simulation of upper and lower cover of mouse is carried through,the fill analyse of original design scheme is carried out with Moldflow sofeware.Through analyzing the experiment results in detail,the problems in design are found,thereby the initial design of injection molding is optimized.The study results indicate that through analyzing the combined cavities mold of mouse with CAE software,some defaults are found,such as imbalance flow(imbalance rate=16.4%),asymmetry pressure in cavities,big locked mold force,the appearance of air traps and weld line.After optimized by Moldflow,the perfect result is got,uniform fill ,balance flow,filling the cavities fully at the same time.The pressure at V/P switch point of gate fell down from 100.8Mpa to 78.43Mpa,biggest locked force decreased from 42.75T to 25.58T,and the flaw of air traps and weld line are controlled reasonably.This paper has practical value for designer of injection molding.