Affordable thermoplastic processing of marine structures

The Advanced Research Projects Agency initiated a major technology effort to develop and demonstrate cost effective, advanced fabrication methods for marine structures. In situ consolidation of thermoplastic composite structures in concert with automated fibre placement offers the premise to produce affordable, high quality parts. In situ consolidation processing eliminates costs due to hand lay-up, bagging and autoclaving, as well as costs associated with acquiring, operating and maintaining an autoclave. Automated fibre placement with high quality and tight dimensional control offers the ability to make complex parts, to lay materials at any fibre angle and path, to vary bandwidth and to cure using in situ consolidation. This paper will present. process-related issues associated with the thermoplastic, hot gas, in situ consolidation of 61 cm diameter cylindrical demonstration models, NOL rings and test specimens to achieve low manufacturing costs. These process-related issues include process adaptation, throughput, part integration and scalability to larger diameter parts. Optimization of these factors in terms of manufacturing costs and quality (void content, mechanical properties) will enhance the development of the in situ consolidation fibre placement process into an affordable manufacturing technology. Thermoplastic materials investigated included carbon/poly(ether ether ketone) and carbon/poly(phenylene sulfide).