Experiments on compression moulding and pultrusion of thermoplastic powder impregnated towpregs

Abstract

Powder impregnation techniques have been developed to increase design and manufacturing flexibility with thermoplastic composites. The effect of pressure, temperature, mould closing rate and time on the consolidation of poly(ether ketone ketone) (PEKK) powder impregnated glass fibre towpregs in compression moulding were studied. A design of experiments approach was used. Isothermal pultrusion experiments using nylon 11 and PEKK powder impregnated glass fibre tows were conducted. These experiments were repeated at different temperatures and pulling speeds. The microstructural changes during coating and consolidation of the powder impregnated tows were studied. Temperature and mould closing rate were observed to be the significant parameters affecting consolidation in compression moulding. Superposition of the pulling force-pulling speed data at different processing temperatures was demonstrated in pultrusion.