A new kinetic and viscosity model for liquid composite molding simulations in an industrial environment

Liquid composite molding is broadly used for manufacturing composite parts. Apart from the preforming of the dry fibrous material, mold filling and curing of the resin are the main steps in the manufacturing process. For process simulation numerical methods, like finite element methods are applied. Flow models describing the flow behavior through a porous medium are well established. The ability to predict and monitor the curing process in liquid composite molding is crucial for manufacturing process optimization in case of application of rapid curing resin systems. Based on differential scanning calorimetry and rheological experiments, cure kinetics and viscosity of a resin system were characterized. A new kinetic and complex viscosity model is proposed to predict epoxy resin properties in numerical modeling of liquid composite molding. The semi-empirical models are simple to use and therefore suitable for process optimization in an industrial environment. Both models were validated by a fitting to the experimental data by the Levenberg-Marquardt method. A process to determine the initial values for the fitting procedure is also proposed. The predictions of the validated models were in good agreement with the measured data, and are therefore applicable for numerical process optimization. Polym. Compos. 25:255–269, 2004. © 2004 Society of Plastics Engineers.