Thermoplastic composites are gaining favour in place of traditional thermoset versions for their toughness, ease of recycling and ability to be manufactured in high volume without autoclaves. The High Volume Manufacture and Inspection Processes for Composite Pipes project aims to develop novel manufacturing and inspection processes for production of cost-effective thermoplastic composite tube, and to fully qualify the material. The consortium comprises Sigma Precision Components (lead), Pultrex, Laser Optical Engineering and University of Manchester. The project will develop a pultrusion process to make high-quality thermoplastic composite tube and a semi-automatic laser shearography inspection system to check for flaws. The carbon /thermoplastic material will also be one of the first to be fully characterised for aerospace use. The partners will need to ensure the processes are capable of achieving cost and productivity targets while maintaining product quality. Sigma is a manufacturer of metallic aerospace pipe assemblies and has developed thermoplastic composite tube technology that can be used for lightweight pipe assemblies and torque shafts. To fully capitalise on market opportunities, Sigma will perform a work package to fully qualify the thermoplastic composite material (overseen and published by NCAMP) through a series of coupon tests. Currently there are very few thermoplastic composites published in the industry's Composite Materials Handbook 17. In addition, the manufacturing costs for the tube need to be reduced, addressed by the two other work packages Although pultrusion is an established technology for making various thermoset composite sections, Pultrex (a UK based manufacturer of pultrusion equipment) will develop innovative solutions to adapt the process for thermoplastic tubes, in particular the heating and cooling systems and consolidation die design. University of Manchester will assist by transferring knowledge from their laboratory pilot process, and maintain close academic interest for teaching purposes. Pultrex also anticipates potential sales of this equipment in other sectors such as automotive. For the third work package, Laser Optical Engineering will adapt one of their existing laser shearography systems to inspect composite tubes for flaws such as inclusions, porosity and delamination. The system will use special lasers, cameras and semi automatic image analysis to inspect the tube more quickly than traditional C scanning techniques. Their innovation will focus on miniaturising a rugged system for both industrial use and for inspecting composite structures on aircraft during maintenance, or even wind turbine blades.

This project will enable a step-change ina current manufacturing process called wet-filament winding where a significant reduction in the consumption of solvents can be achieved in conjunction with reductions in the volume of waste material generated. This in effect will transform the workplace in terms of air-quality and significantly reduce emissions to the atmosphere. In the new manufacturing technique, a conventional resin bath in not used. Instead, the components of the resin system are mixed on-demand and dispensed using the optimum volume to impregnate the fibres. Productivity and quality-imporvements will be obtained by: - a reduction in the impregnation time via fibre spreading. Proof-of-concept experiments have shown that the properties of filament wound composites produced using the new technique are equivalent to or better than those obtained using conventianal wet-filament winding. The socio-economic benefits of this proposal are very significant. A recent site trial has demonstrated that the so called clean filament winding technology can be retrofitted easily on conventional filament winding machines. The Exploitation Plan for the project consists of three strategies: - new build; - Retrofit; - End-users in the consortium.

The aim of this project is to develop a new pultrusion technique that is environmentally friendly and one that permits new resin systems such as custom formulated polyurethanes to be evaluated. In the conventional process, the reinforcing fibres are impregnated in a resin bath and then passed through a heated die to cross link the resin and to shape the pultruded component. In the new manufacturing technique, the components of the resin will be stored in separate containers and pumped on demand using a custom designed polyurethane resin component delivery system. Efficient and effective impregnation of the fibres will be achieved using a novel combination of efficient fibre spreading and an injection-head. The green credentials of this new manufacturing technique will be assessed using life cycle assessment.

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The project aims to develop a novel process for the conversion of unidirectional [UD] prepreg tape to off-axis [OA] form. A prototype converter will be developed, to take UD tape widths up to 100mm, to handle matrices with a melting temperature [Tm] range of 150-400 C and deliver OA products with fibre orientations from 10 to 90 , at widths of up to 1.2m. The influence of input tape composition will be studied. Individual ply products will be comprehensively characterised with regard to fibre orientation, product width and flatness and the resulting multi-ply laminates with regard to mechanical performance and formability. The equipment design will combine low energy and labour requirements with high flexibility in terms of OA specification and product quality. Key variables influencing processing speed and product quality will be identified during a full evaluation of the process economics. Laminates made from these materials will be used to produce and evaluate selected demonstrator parts.