Some aspects of manufacturing prepregs for long-dimensional products from composite materials with a thermoplastic binder

Technology for producing parts from composite materials with a thermoplastic binder differs from traditional manufacturing methods which use thermosetting resins and therefore it requires new design and technological solutions. The approach proposed in this paper involves coating carbon filaments with a layer of thermoplastic melt at the prepreg preparation stage to ensure its more uniform distribution and deeper impregnation at the product molding stage. To describe the rheological properties of a polyether ether ketone melt (PEEK), a generalized Carreau model was applied and its material constants were determined. Based on the finite element method, a numerical model of the process of applying a layer of thermoplastic on a carbon filament in an axisymmetric die was constructed. The velocity, pressure and temperature fields are calculated, and the effect of applied pressure and core drawing speed on the applied layer thickness is determined. The required layer thickness is determined from an equality of the cross-sectional areas of the applied layers and the total area of voids between the filaments and between the carbon fibers...