Material characterization for flow modeling in structural reaction injection molding

Abstract To support mold filling studies in liquid composite molding, a chemorheological model has been developed that describes the viscosity of an amine‐cured epoxy resin of the type used in structural RIM. The model predictions are compared with results from Monte Carlo network simulations and DSC data. The viscosity model is then used to estimate the principal in‐plane permeabilities of fiber reinforcements using data taken directly from an SRIM process. The experimental method, based on a radial solution to Darcy's law, yields both the wetting and wetted permeabilities. The method has been demonstrated for two plane random reinforcements and indicates negligible difference between wetted and wetting permeabilities at the flow rates considered. The results compare favorably with existing data from radial and rectilinear flow bench rigs.