Processing technologies for continuous fibre reinforced thermoplastics with novel polymer blends

Continuous fibre reinforced thermoplastics (CFRT) for high performance applications are often based on the high-priced PEEK matrix combined with a carbon fibre reinforcement. The potential of blending PEEK with less expensive high temperature thermoplastics like PEI, PES and PSU will help to reduce costs. The research work mainly focuses on the production of semi-finished sheets consisting of such polymer blends and carbon fibre reinforcements. In this context a continuous prepregging method has been realised which combines the matrix (powder) with the textile to a manageable material with a defined weight composition. A subsequent static pressing process leads to fully impregnated and consolidated CFRT sheets. The laminates are then characterised regarding thickness, bending stiffness and quality of impregnation. So far a strong influence of the pressing dwell time on impregnation could be proved. Thereby a generally good correlation between the microscopic views and the mechanical data of neat PEEK and the blend systems occurred. Some blends were identified to enable mechanical properties and permit processing methods that are comparable to neat PEEK. Thus the blend technology can be considered as an alternative to provide more cost-effective CFRT sheets for high performance demands.