The consolidation of commingled thermoplastic fabrics

Abstract Commingled fabrics composed of yarns containing both the reinforcement and the matrix in fiber form are an innovative preform for thermoplastic composite materials. The material is consolidated into a rigid structure by the application of heat and pressure. A mathematical model of the consolidation process for commingled fabrics has been developed. The model predicts the variation of laminate thickness, fiber volume fraction, and void content during the consolidation process as well as the time required to reach full consolidation. Materials composed of initially separate, commingled or cowoven fiber bundles are considered. The influence of fiber velocity induced by compaction on the flow of matrix is accounted for. An equivalence factor has been derived so that a one‐dimensional flow analysis may be used to model the impregnation of elliptical bundles of varying aspect ratio. This permits an analytic solution to the governing equation for fiber bundle impregnation. The model was utilized to examine the influence of various material and processing parameters on consolidation behavior.