Induction heating of continuous carbon-fibre-reinforced thermoplastics

This paper addresses the experimental investigation of induction heating of continuous carbon-fibre reinforced thermoplastics. The influence of the pr ocess parameters electromagnetic frequency, generator power, distance betwe en induction coil and laminate, coil geometry and laminate lay-up on the he ating rate and the heat distribution have been investigated in stationary e xperiments. It was found that all investigated parameters have significant influence on the heating behaviour and that a quadratic dependence is domin ating. Heat is only generated when closed fibre loops exist, through which current can flow. The quality of the fibre junctions in a laminate, especia lly the contact length, was found to be of major importance. Thus, for exam ple laminates with unidirectional fibre reinforcement, which do not contain fibre junctions, cannot be heated. Experimental evidence has shown that in duction heating of carbon-fibre-reinforced thermoplastics is based on Joule losses. (C) 2000 Elsevier Science Ltd. All rights reserved.