A novel technique for making composite fibre and fabric-reinforced tubes, belts and other cylindrical structures is being developed by a team at TWI.
This technique harnesses the centrifugal force to wind and hold fibres in place against the inside wall of a rotating mould. Inside the mould, a composite is formed as an adhesive which cures to produce a cylindrical component.
This technology is believed to have a number of very good technical advantages including the ability to wind polymer composites without 'tack' and the ability to wind drive belts with reinforced teeth.
The polyurethane belt turned inside out
The process leads to seamless, near net-shaped products which are dynamically balanced during manufacture which makes them ideal for use in applications where rotation is involved. An example of such a product is high performance car tyres, parts of which could be manufactured using this technology.
The key to the technology is the use of the centrifugal force to draw the fibrous reinforcement into the mould where its arrangement can be controlled via the orientation of the fabric or fabric feeding system. In this way composite tubes with reinforcement distributed for optimum mechanical properties can be manufactured simply.
Schematic of the centrifugal winding process Centrifugal technology allows products to be manufactured from the outer surface instead of being wrapped around a mandrel and manufactured from the inner surface. Immediate applications are anticipated in the areas of drive belt and composite tube manufacture.
Further details are available from Roger Wise, Wayne Thomas, Keith Johnson or Peter Temple-Smith. E-mail: pci@twi.co.uk
