TY - GEN

T1 - Viscoelastic Modelling of Polymer Melts and Rubber Compounds

AU - Friesenbichler, Walter

AU - Stieger, Sebastian

AU - Kerschbaumer, Roman Christopher

AU - Berger-Weber, Gerald

AU - Neunhäuserer, Andreas

AU - Mitsoulis, Evan

PY - 2020

Y1 - 2020

N2 - Thermoplastic melts and rubber compounds are viscoelastic fluids.They show a complex flow behavior, which is influenced by various factorssuch as polymer type, molar mass distribution, recipe, filler-filler network andin some cases wall slippage. Most of the state-of-the-art simulation softwarepackages use viscous material models for the calculation of the flow field aswell as pressure and temperature distribution, neglecting the viscoelasticnature of polymers. This simplification may lead to an underestimated pressuredemand in injection molding simulation.This contribution presents how to correctly measure viscosity data (shearand extensional viscosity) for thermoplastics and rubber compounds taking intoaccount the pressure dependency of the viscosity and the influence of viscousdissipation in capillary rheometry at higher shear rates. Moreover, a guidelineon how to best fit rheological data with the viscoelastic K-BKZ/Wagner modelis outlined. Comparing CFD simulation results to experimental data, only theK-BKZ/Wagner model is able to correctly predict pressure losses of contractionflow dominated geometries. Examples will be given for NBR and PP-PNC.

AB - Thermoplastic melts and rubber compounds are viscoelastic fluids.They show a complex flow behavior, which is influenced by various factorssuch as polymer type, molar mass distribution, recipe, filler-filler network andin some cases wall slippage. Most of the state-of-the-art simulation softwarepackages use viscous material models for the calculation of the flow field aswell as pressure and temperature distribution, neglecting the viscoelasticnature of polymers. This simplification may lead to an underestimated pressuredemand in injection molding simulation.This contribution presents how to correctly measure viscosity data (shearand extensional viscosity) for thermoplastics and rubber compounds taking intoaccount the pressure dependency of the viscosity and the influence of viscousdissipation in capillary rheometry at higher shear rates. Moreover, a guidelineon how to best fit rheological data with the viscoelastic K-BKZ/Wagner modelis outlined. Comparing CFD simulation results to experimental data, only theK-BKZ/Wagner model is able to correctly predict pressure losses of contractionflow dominated geometries. Examples will be given for NBR and PP-PNC.

M3 - Conference contribution

SN - 978-3-662-60808-1

SP - 270

EP - 282

BT - Advances in Polymer Processing 2020 Christian Hopmann Rainer Dahlmann Eds. Proceedings of the International Symposium on Plastics Technology

PB - Springer Vieweg

ER -