Recycling CF/PEEK offcut waste from laser assisted tape placement: Influence of overlaps and gaps

A recycling method for waste CF/PEEK prepreg tapes is proposed that uses offcuts from laser assisted tape placement (LATP) processing, without shredding, grinding or further cutting. Laminates (using the prepreg waste) representing different configurations were manufactured considering overlaps and gaps reflecting observed defects in LATP. Interlaminar shear strengths (ILSS) with 0° fibre (Parallel) and bending strength for 90° fibre (Normal) directions were measured. The parallel samples with 3 mm overlap had the highest ILSS (100.3 MPa) while the 2 mm gapped samples had the lowest ILSS (58.7 MPa). The Normal samples failed at the surface due to matrix-dominated failure providing bending strengths between 44.0 MPa and 82.1 MPa. Failure mechanisms were identified similar to that of non-recycled composites reported in the literature (50–120 MPa), indicating that the recycled prepreg tapes retained approximately 84 % of the ILSS of the highest reported values.