Carbon bicycle recycling prospects blooming

United States – Trek, the US bicycle manufacturer, faces the challenge of recycling up to 25 tonnes of carbon fibre composite material per year to help meet its new zero landfill objective. A solution may now be in sight thanks to the company’s collaboration with Materials Innovation Technologies (MIT) at its production plant in Waterloo, Wisconsin.

Bicycle producers worldwide rely on carbon fibre for its strength and light weight, but it is considered difficult to reprocess successfully. One issue is that non-compliant moulded parts use carbon fibre of varying grades, so any higher-performance material going into the mix will be downgraded.

Trek is now chopping the material into 25mm square pieces which are fed into a patented pyrolytic oven. The virtually oxygen-free environment removes the binding resin without destroying the properties of the fibre.

The technique is not perfect because of the multiple grades of material involved. ‘But at least it’s not wasted and can still be reused in parts that typically use standard-grade carbon fibre,’ explains James Colegrove, Trek Senior Composites Manufacturing Engineer.

Even though Trek is not yet ready to build high-end performance frames from reclaimed carbon fibre, it is successfully reusing the material, initially just in the US, in secondary parts that don’t depend on continuous fibre reinforcement. ‘We may need to set up similar programmes around the world to minimise the logistical dilemma,’ Mr Colegrove said.

There could be cost savings as well as environmental benefits, though it is too soon to quantify this. ‘We know that the cost of reclaim fibre is significantly lower than the cost of producing raw material,’ Mr Colegrove added. ‘If you are making a part that uses chopped fibres anyway, it makes a lot more sense to use reclaimed fibre.’