HEATED CHAMBER WINDING OF THERMOPLASTIC POWDER-IMPREGNATED COMPOSITES.1. TECHNOLOGY AND BASIC THERMOCHEMICAL ASPECTS

The market for low-cost composites that can be manufactured by automat ed processes in large volumes is increasing; mass production applicati ons continue to grow in several fields such as land transportation, co nstruction and infrastructure. Progress in composite materials technol ogy is helping and this trend will be more pronounced in the future, c onventional materials like metals being replaced with fibre-reinforced composites in conventional as well as innovative infrastructure appli cations. Due to the constraints of continuous reinforcement, low cost and mass production, one major candidate to supply the infrastructure market will be pultrusion and filament winding technologies. Current m aterials used in the held of large volume applications are injection-m ouldable polymers reinforced with short or long glass fibres for semi- structural components. Additional use is made of glass mat thermoplast ic sheets, for which the processing technologies have already been est ablished in a large number of applications. Advanced thermoplastic com posites based on highly aligned, continuous fibres represent a big ste p in terms of mechanical performances, offering to thermoplastic polym ers the chance to become structural components. Conversion of the vari ous continuous fibre-reinforced thermoplastic materials into useful pa rts and components is dependent on the intermediate product forms. The scope of this paper is to describe a promising method for manufacturi ng wound artefacts, the semi-finished material forms containing powder and the equipment developed for fully automated processing. A descrip tion of the main thermochemical aspects involved in the process and th e relevant analytical modelling is also given.