Flexural properties of pultruded carbon/PEEK composites as a function of processing history

An extensive research programme investigating the thermoplastic pultrusion process has been undertaken. As part of this research effort, the influence of process parameters on the mechanical properties of the composite has been studied. A study of the influence of the independent processing parameters on the ultimate flexural strength and flexural modulus of unidirectional carbon fibre-reinforced polyetheretherketone composites is presented. A process-parameter dependency is found and is attributed to processing-induced differences in the matrix crystallinity, where a decreasing degree of crystallinity translates into decreasing flexural strength. The flexural modulus appears to follow the same trend as the strength, but this dependency is less pronounced.