Mold filling analysis in vacuum-assisted resin transfer molding. part I: SCRIMP based on a high-permeable medium

Mold filling in SCRIMP based on a high-permeable medium is complicated because of the considerable difference in the permeabilities of the fiber reinforcement, the peel ply and the high permeable medium. The objectives of this paper are to understand the flow mechanism through flow visualization experiments and to present models that can be used to predict the filling time and flow pattern. Permeabilities of a stitched fiber mat, a high-permeable medium and a peel ply were measured. Flow visualization of SCRIMP mold filling was carried out under various molding conditions. It was found that although the resin flowed faster in the high-permeable medium than in the fiber reinforcement, the flow front lead-lag was not very large and it remained nearly constant through the entire mold filling process. A three-dimensional Control Volume/Finite Element Method (CV/FEM) was adopted to solve the flow governing equations, i.e. the Darcy's law, and the influences of the flow properties of the high-permeable medium, the fiber reinforcement and the peel ply on filling time were investigated. Based on experimental observations and CV/FEM simulation, a simplified leakage flow model is also presented. The comparison of experimental and simulation results show good agreement.