Reaserch On The Numerical Simulation And Design Of Mold For The Injection Moulding Of Plastics With Thin-wall And Deep-rib

Warpage is the major defect that impact molding quality of the plastic products,and serious warpage can cause plastic parts not assembled into scrap. warpage effect onthe forming quality is more significant due to its special structure to the plastics withthin-wall and deep rib. In this paper, taking notebook battery cover plastic parts as theexample, application of numerical simulation technology to the molding process isfinding the main reasons of warpage and proposing improvement measures, providingthe basis for the design of mold and injection process parameters. In the purpose ofreducing the cost of mold development and improving the quality of products.In this paper, firstly the injection molding process technology and the thin-wallinjection technology current situation of the researches at home and abroad were brieflyintroduced. Secondly, the rheological properties of the polymer melt and the principleand process of the simulate plastic injection molding process were introduced.Application of Moldflow software simulate injection molding process of notebookbattery cover plastic parts to to analyze the filling process and warpage to obtain partswarpage and warped reason. We get result warp values from doing16times simulationexperiments with the plan of orthogonal experiment in five factors and four levels anddifferent values of process parameters of dwell injection temperature, injection time,mold temperature, dwell pressure, dwell time. The influences of various injectionprocess parameters are analyzed, it is obtained to the optimized parameter combinationto minimum the warp distortion and established relation process parameters withwarpage. Finally, according to the results of simulation analysis, the mold was designed for plastic parts by UG software, and the best molding process parameters and moldstructure were verified rational by the actual production of plastic parts.The results show that: regional shrinkage is the main reason for the warpage ofplastic parts, Optimization of process parameters can reduce the deformation causedregional shrinkage. For the thin-wall and deep rib plastic parts, the order of the warpagestrength of plastic parts with various process parameters is follows: injectiontime>holding pressure>dwell time>mold temperature>injection temperature. When theinjection temperature is300℃, mold temperature is90℃, injection time is0.9s, thedwell time is3.5s, holding pressure is110Mpa, the process parameters of plastic partscan achieve optimization. In the initial process conditions, the warpage of plastic partsis1.258mm, after using the optimized process parameters the the warpage is0.126mm.