the effect of thickness variation on the formed film used for IMD processes is very important. a non-uniform wall thickness is one of the major factors in product failure during injaction molding, leading to warpage, shrinkaqe,wrinkling, and rupture. by the same token, the material properties, such as viscosity, and the elastic character of teat film, have a significant influence on the polymer flow. thus, a non-uniform film will easily cause stretching and deformation depending upon the plug shape, plug depth and correlative process parameters during the thermoforming process. in order to understand the effect to thickness distribution under different process conditions for thermoforming process, we utillize a thickness gauge to measure the film thickness at five locations, ad shown in fig3b . point 1 is in the centre of the bottom area ; point 2,3 and 4 are just within the regions of the sidewall of the part; and point 5 is located in the flange area, these 5 point of thickness weremeasured before and after deformation. the variation rate of the formed film in this study can be calculated and described as