TWI Industrial Member Report Summary 1019/2012
By M Kwak
Two areas of microwave processing of materials have been explored; curing of carbon-fibre reinforced epoxy pre-preg, and welding of glass-fibre reinforced polypropylene composites. The manufacturer of the new HEPHAISTOS VHM claims it has tackled key issues associated with microwave processing of composites, such as non-homogeneous microwave distribution, the difficulty of using metallic tooling and vacuum bagging in a microwave environment, and arcing, thus providing significant advances compared with previous systems. The different, and sometimes inconclusive results obtained in past work can be attributed to the different systems employed.
The VHM microwave has allowed researchers to assess more accurately the real benefits/disadvantages of microwave technology for processing polymer matrix composites (PMCs). The performance of the samples produced has been evaluated using differential scanning calorimetry (DSC) and mechanical testing.
The results have been compared to samples cured conventionally and also in some respects, to results obtained by other researchers. There was, however, some difficulty in carrying out a direct comparison with results obtained by other researchers due to the different procedures employed. It will however be possible to investigate whether similar phenomena are observed with the VHM microwave.