| The majority of mobile phone users are keen on thin,small size,large screen mobile information terminal with rapid development of information technology.In view of the above characteristic,mobile phone manufacturers without exception to choose plastic shell in product design and manufacturing process,it is popular with people because of its light weight,high strength,good toughness,and the characteristics of the plastic on behalf of steel has become an important concept of mobile information terminal design developers.Due to the influence of external factors,plastic injection molding is prone to warping,weld marks,cavitation and other common quality defects in the process of production.The mobile phone shell is taken as the research object,the design method of injection mold is studied,CAE model is established to simulate the process of injection molding based on the software of Moldflow,and the process parameters of are optimized by orthogonal experiment.First of all,a mobile phone shell is taken as the research object,and the design process of injection mold is described in this paper,which mainly includes the selection of parting surface,the choice of injection machine,molding parts design,the design of gating system,the lateral axis core design of organization,the design of the cooling system design,guidance system,and the selection of the die set and so on.Secondly,the mathematical model of injection molding is established,it includes the mathematical model in the process of filling and warping deformation mathematical model.injection molding process of mobile phone shell is simulated based on numerical simulation software of Moldflow,and it includes the import,mesh and repair of established mobile phone shell model,selection of molding material,casting and cooling system according to preliminary simulation system.The rationality of the model mesh,material selection and the establishment of the cooling system are verified by the simulation of the injection molding process of the mobile phone shell.In addition,the mobile phone shell away from the gate of the upper and lower ends of parts through the analysis,the filling time is the longest,shrinkage index and warpage is maximum,and the cavitation and weld defects of mobile phone shell are more serious.Finally,the influence of the process parameters on the warpage of the mobile phone shell is studied based on the orthogonal test,and the best process parameters combination of injection molding for mobile phone shell is obtained.That is,the mobile phone shell in the mold temperature is 70?,melt temperature is 280?,injection time is 0.63s,holding time of pressure is 19s,holding pressure is 190 MPa and cooling time is 110s to injection molding,it can get the minimum warpage and the best quality of plastic parts is obtained.It is found that the degree of influence for each process parameter on the warpage by the variance analysis of the orthogonal test results is as follows:the cooling time,the holding time,melt temperature,mold temperature,injection time and holding pressure.In addition,the cooling system,the forming process and the pressure maintaining curve are optimized respectively based on the Moldflow software,and good results are obtained.Therefore,it can better guide the actual production of enterprises. |
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