Studies On The Forming Problem Of IMD Film PET Material During The Matched Metal Forming

A mold company often met many problems with IMD(in-mould decoration)films,such as wrinkle,pattern deformation.For this situation,this paper studied the forming problem of PET flim during the manufacture process through numerical simulation.In view of the situation of lack of PET film material model,made the film uniaxial tensile experiment,studied mechanical properties of thin films.Using phenomenological modeling approach,divided the strain of material into viscoelastic strain and plastic strain,constructed a model of viscoelastic plastic for PET film using three parameter model and J2 flow theory and calculated the parameters in the model through the experiment data to.Writed VUAMT material subroutine using fortran language used for simple tension simulation of film to verify the correctness of the material model.The result showed that:Simulation results and experiment results matched very well,showing that the viscoelastic plasticity model can describe the mechanical properties of PET film well.Built finite element analysis model of the PET film metal clamping according to the actual working condition of forming,Including the design of geometry model,contact properties,boundary constraint,the load applied.Leaded the viscoelastic plasticity model into the main program When defining material and implemented the thin film of metal mould.And then implemented the simulation forming of PET film.Divided the film into flange fillet,flange straight,die fillet,die corner,punch corner,straight walls,floor and punch corner areas according to the shape of the film forming.Studied the mold size,temperature,lubrication and blank holder force of molding effect using Abaqus finite element software.Analysised film flange wrinkling degree and the trend of punch corner fracturethe.Compared research results with the results of PC film,the magnesium alloy,discoverying that process parameters on the influence of different material is roughly the same.The results showed that:the viscoelastic plasticity model can be used for the finite element molding and the process parameters obtained by the numerical simulation has some help for the production practice.