Tensile behaviour of thermoplastic weft-knit composites

In-plane deformation of thermoplastic weft-knit textile composites under tensile loading in both macro and micro-scale is studied. An interlock knitted preform was produced by co-knitting polyester filament yarns as fabric reinforcement with polypropylene yarns as matrix material. The benefits of knitting over other fibre architectures are detailed. Energy absorption capacity for specific engineering applications is discussed. Comparison of tensile properties is made between composites and their individual components. The methods of producing interlock limited knitted fabric preforms are explained. Compression moulding of these produced flat thermoplastic composite panels. The hot-pressing process is examined. The method and equipment used in tensile testing are specified. The tensile curves of pure PP matrix, fabric preform and knitted composites in the walewise, coursewise and diagonal directions are noted. The walewise direction demonstrated better tensile properties. The matrix contribution on most of the load sustained in the elastic region allied with other factors provided a better combination of properties in the knitted composites than in individual components.