Composite manufacturing by using a novel modular 2.45 GHz microwave processing system

A novel industrial microwave system for automated processing of carbon fibre reinforced plastics has been developed at Forschungszentrum Karlsruhe and tested for commercial use. The system integrates advantageously the basic processing steps as tooling, tempering of the resin and lay up, the impregnation of the fibres, pre-forming techniques as well as finally the process curing of the composite structures. Composites for aerospace applications in prepreg and wet technology have been successfully fabricated and investigated for quality and certification issues. Features of the system, as well results on the material investigations are presented. The use of microwaves shows new approaches on the process interaction for the fibre materials, precursors, resin systems, lay-up preparation etc. with direct consequences on the adjustable material properties. CFRP materials are heated volumetrically with microwaves, offering the opportunity of very high heating rates. In comparison to conventional heating where the heat transfer is diffusive and depends on the thermal conductivity of the material, the microwave field penetrates the material and acts as an instantaneous heat source at each point of the sample.