Characterization of viscous response of a polymer during fabric IMD injection process by means a spiral mold

Abstract Injection molding is a plastic transformation process to produce complex parts; an efficient way of decorating a part is to do it during the molding cycle, introducing decorated film or fabric inside the mold. One of the most important tools to optimize the injection cycle is to make simulations, but the recognized software do not have potential to simulate IMD (In Mold Decoration) process because the behavior of the polymer flowing over fabric is unknown. This article is focused on the design of a methodology to characterize polymer rheological behavior from a macroscopic point of view, in order to estimate a useful viscous model for use in CAE software by means of a spiral mold and pressure sensors located in it, instead of a rheometer. However, the test temperature of polymer is not constant during the test when the spiral mold method is used, and it is necessary to introduce corrections. For authors, this study is a novelty because any author has used a spiral mold to characterize the rheological behavior of polymers injected over fabric, and the exposed methodology will be very useful to adjust IMD pressure drop on computer programs.