Extrusion/hot pressing processing and laminated layers of continuous carbon fiber/thermoplastic polyurethane knitted composites

Abstract Extrusion is employed to combine carbon fiber tows and thermoplastic polyurethane (TPU) blend. TPU‐cladded carbon fibers undergo knitting to form carbon fiber knitted composites. Microscopic observation proves that the compound carbon fibers are composed of a double‐layered structure with interfacial bonding and fiber axial alignment. In addition, the TPU coating can reduce friction during knitting, which provides the carbon fiber knitted composites with flexibility and resilience. Regarding the mechanical properties, the tensile strength is in direct proportion to the number of lamination layers. In particular, six‐layered knitted composites exhibit an optimal tensile strength of 43.72 MPa, whereas four‐layered knitted composites exhibit optimal tensile elongation. Through the manufacturing and evaluations in this study, continuous carbon fibers can be fabricated via extrusion, thereby obtaining a knitted structure that can be laminated to strengthen the mechanical properties and electromagnetic interference shielding efficacy of the laminated composites. Large composites can also be achieved, which overcomes the limits of continuous carbon fibers in subsequent production. © 2021 Society of Industrial Chemistry.