Experimental measurement and modeling of film thickness distribution in film insert injection molding process

In this study, the effect of flow rate and melt temperature on the film thickness during the film insert injection molding (FIM) process is investigated. Many studies have rigorously investigated viscoelastic deformation and severe warpage during the FIM process. However, very few studies have examined the change in the film thickness, despite it being an important aspect for achieving a high-quality final product. In this regard, changes in the film thickness during the FIM process are experimentally and analytically examined in this study. Some notable changes are observed in the film thickness along both center and edge paths in the melt flow direction. This is attributed to the combined effect of rapid heat transfer from the hot polymer melt and compressive effect from melt pressure. Moreover, a simple mathematical model is created based on a dimensional analysis, which helped in predicting their effects on the film thickness distribution.