Study On IMD Film Forming By One Mold Four Chamber Partition Heating

IMD technology(In-Mold Decoration,also known as In-Mold Decoration technology)is an increasingly popular technology for molding and surface decoration of polymer materials in these years.It is mainly used in electronics,home appliances,communication equipment,automobiles,etc.The field has great market value.There are many factors that affect the quality of IMD films.Among them,films high pressure molding is an extremely critical link.However,there are many defects in the molding process of IMD films,especially in the high pressure molding process of IMD films.In the high-pressure molding process,the molding parameters of the films must be determined.The vast majority of them are methods of trial molding and mold repair.However,the research and development costs of this method are quite high.For the common films thinning rate is too large,uneven thickness distribution,the formation of a larger area covered by the film surface of the ink is pulled open,the films surface pattern deformation and other issues,so IMD product failure rate as high 30~40%.Therefore,it is of great research value to deeply study the defects of the IMD films forming process in the high pressure molding process,and to seek new process methods or to improve the optimization process.Against this background,the research topics proposed in this paper,the main research content includes:(1)The infrared radiation heating model of IMD films was established,and the temperature field distribution of PET films was simulated and analyzed using Matlab.The surface temperature distribution of IMD diaphragm was studied.(2)Taking PET films as an example,the samples were subjected to hot multidirectional tensile tests to study the mechanical properties of PET films at different temperatures.Theconstitutive model of the IMD films is constructed by stress and strain curves of the PET film at different temperatures obtained by tensile tests.A sub-program of the IMD diaphragm material is prepared to provide a material model for the finite element simulation of high-pressure forming of a four-cavity partitioned IMD film..(3)ABAQUS software was used to establish the finite element model of IMD films one-cavity,four-chamber,partition heating and high pressure molding.Different process parameters were used to perform finite element simulation on the partitioned heating of PET film materials under different temperature combinations.The effect of pressure value,blank holder force,and friction conditions on the film forming performance.(4)The IMD films of a complex part is subjected to high-pressure forming process simulation under a variety of temperature subarea heating modes and the corresponding zoned heating IMD process forming experiment,and the finite element simulation is verified by comparing the experimental results with the simulation results.The accuracy of the results and the feasibility of a zoned heating process.