Multiple Injection Port Simulation for Resin Injection Pultrusion

Resin injection pultrusion is a continuous process for manufacturing composite materials. Complete wet-out of the reinforcement fibres in the resin injection chamber is essential for producing good quality pultruded parts. The magnitude of the injection pressure is extremely important to achieve good wet-out of the reinforcement fibres. At high pull speeds, high viscosity, or high fibre volume fractions, the injection pressures required to achieve complete wet-out are very high and are practically very difficult to achieve. This work focuses on reducing the injection pressure needed to achieve complete wet-out by using a multiple injection port system for epoxy/glass rovings and polyester/glass rovings composites. The recommended injection pressures for complete wet-out are predicted for a variety of processing parameters. Darcy's law for flow through porous media is employed for modelling the fibre/resin system of injection pultrusion. The governing equations are solved via the finite volume method to predict the resin pressure field, the resin velocity field, and the location and shape of the resin flow front. Different permeability models ^1,2 are used to determine the transverse permeability and the longitudinal permeability.