Rheological In-Mold Measurements and Characterizations of Sheet-Molding-Compound (SMC) Formulations with Different Constitution Properties by Using a Compressible Shell Model

The rheological characterization of Sheet Molding Compound (SMC) and its modelling is crucial for reliable process simulations. In the past, characterization and material modelling were mainly focusing on SMC with low glass fiber content and a high filler fraction. Due to new application areas, SMC without fillers and with high glass fiber contents, and SMC with carbon fibers become more important. Therefore, these three types of SMCs are characterized in this work, using an inline rheological tool. Differences regarding their compressibility and their flow dependency are identified and considered in an analytical shell modelling. The comparison of the different materials leads to a better understanding of the phenomenological parameters related to the viscosity and friction in the models. Furthermore, the importance to properly consider all relevant material-specific effects becomes evident.