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 automated processes in large volumes is increasing; mass production applications continue to grow in several fields such as land transportation, construction and infrastructure. Progress in composite materials technology is helping and this trend will be more pronounced in the future, conventional materials like metals being replaced with fibre-reinforced composites in conventional as well as innovative infrastructure applications. 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 materials used in the held of large volume applications are injection-mouldable polymers reinforced with short or long glass fibres for semi-structural components. Additional use is made of glass mat thermoplastic sheets, for which the processing technologies have already been established in a large number of applications. Advanced thermoplastic composites based on highly aligned, continuous fibres represent a big step in terms of mechanical performances, offering to thermoplastic polymers the chance to become structural components. Conversion of the various continuous fibre-reinforced thermoplastic materials into useful parts and components is dependent on the intermediate product forms. The scope of this paper is to describe a promising method for manufacturing wound artefacts, the semi-finished material forms containing powder and the equipment developed for fully automated processing. A description of the main thermochemical aspects involved in the process and the relevant analytical modelling is also given.