CHARACTERISATION OF THERMOPLASTIC MATRIX COMPOSITES (TPC) USING VARIABLE FREQUENCY

Abstract: In most industrial microwave processing operations, the frequency of the microwave energy launched into the waveguide or cavity containing the sample is usually fixed. This brings with it inherent heating uniformity problems. This paper describes a new technique for microwave processing, known as variable frequency microwave (VFM) processing, which gets rid of the problems brought about by fixed frequency microwave processing. In VFM processing, microwave energy over a range of frequencies is transmitted into the cavity in a short time, eg 20μs. It is therefore necessary to find out the best frequency range to process a material. This paper describes the process of finding the best range frequency for microwave processing of five different thermoplastic matrix composites using the VFM facilities. The optimum frequency band for microwave processing of these five materials was in the range of 8 – 12 GHz. This data enables one to join the above five materials using microwave energy at their most favourable conditions