Founded in 1984 and employing almost 500 people in the UK, Prodrive designs and manufactures lightweight composites for a range of applications across the automotive, motorsport, aerospace, marine, defence and other specialist sectors.The company has been working in collaboration with research engineers at the AMRC on its P2T (Primary To Tertiary) philosophy, which is used for manufacturing recyclable composite components that can satisfy end-of-life requirements (specified in Directive 2000/53/EC) without any compromise in the performance of the original parts. P2T not only simplifies recycling, but endows a composite material with the potential to fulfil three or more useful lifetimes.
Hannah Tew, partnership lead at the AMRC Composite Centre, says her team has been working with the company to further advance its recyclable composite process closer to full production. This effort has focused primarily on allowing for automation, making it possible to achieve medium-to-high volumes at substantially lower costs. Another area has been to look at the recyclable nature of the materials used and increase the technology’s attraction to other industries
“The results from our initial press trials look promising and we’re very much looking forward to supporting Prodrive in automating the process going forward,” she says.
As P2T composites do not require heat or pressure during manufacture, there is no need for an autoclave, thus reducing costs and enabling the scaling up of production without major investment.
The process uses a reactive thermoplastic resin instead of a thermosetting type; a plastic monomer is reacted with a catalyst in the presence of the fibres to produce a cured laminate.
Prodrive believes it is the first company to develop this technique with recycled fibres, which emerged through a development programme with an automotive OEM customer that required a high-performance structural material with lower environmental impact than conventional composites.
“End-of-life recycling is one of the biggest debates in the composites world today,” says John McQuilliam, chief engineer at Prodrive Composites. “It affects automotive manufacturers and wider industries too, such as marine, where old fibreglass boats are often broken up and sent to landfill. The main barrier to recycling has been the type of resin used; thermosetting resins predominate but these cannot be readily recycled.
“In partnership with the AMRC, a series of large trial panels have been produced using an innovative process which can readily be automated,” he continues. “These trials have demonstrated that recyclable composite panels can be produced at a rate and cost to suit many industries. The unique feature of the P2T process is the reduced tooling cost and lead time compared with existing metallic or composite solutions.”
Traditionally, the composites industry has been based on the supply of rolls of ‘pre-preg’ (woven fibre sheets pre-impregnated with resin) that customers then lay up in moulds to produce 3D parts, curing through heating and pressurising to fix the final shape. Thermosetting resins are considered convenient materials to support this supply chain but, as tighter end-of-life regulations are introduced, better alternatives are required.
The advantages of composites produced by the P2T process is that they can be recycled multiple times. High mechanical properties are obtained during first use of the virgin fibres, enabling highly-loaded structural items to be manufactured.
At the part’s end-of-life, the fibres and, potentially, the resin, can be recycled, supplying much of the raw material for a secondary part, such as a body panel. When the secondary component reaches the end of its life, being thermoplastic, it too can be chopped and remoulded into new parts with properties suitable for 3D solid components. This tertiary component can itself be recycled several times into lower grade parts.
The ongoing research between the AMRC and Prodrive Composites is set to expand considerably over the coming year, and is being closely monitored by numerous companies in various industries looking to improve their environmental impact with high-performance lightweight components.
