Reusing rubber – the road from tyre to timber

Around five million tyres are disposed of each year in New Zealand. Some 30 per cent of these end-of-life tyres (ELT) are recycled, but 70 per cent end up in our landfills or are illegally dumped. In addition to the enormous pressure placed on landfill space, getting rid of waste tyres is costly, and stockpiles of tyres are a fire hazard.  

Finding solutions to this environmental challenge is the focus of a two-phase research and product development project led by Scion’s Dr Grant Emms and Asona (a specialist New Zealand manufacturer, distributor and installer of acoustic decorative ceiling and wall finishes serving the commercial interior market). Together, we have been investigating the creation of a New Zealand based ELT rubber and processing facility to recycle crumbed rubber into high-value acoustic building products such as flooring.
Grant says, “We’ve created a number of small scale samples with Asona, so we’ve proven we can do it.”

Around three and a half million tyres end up in New Zealand landfills each year or are illegally dumped. Finding sustainable solutions to end-of-life tyre problems are a challenge tackled by Scion.

This project is one of three rubber recycling projects funded through the Ministry for the Environment’s Waste Minimisation 2015 funding round.

One project is undoing the vulcanisation process that converts raw rubber into hard, durable tyres. Scion is developing an underpinning extrusion process, based on equipment currently available, to revert the cross-linked structure of tyre rubber, and produce the devulcanised, crumbed rubber for use as a high-performance binder for New Zealand’s roads.

The final project is adding recycled rubber into manufactured wood panels for acoustic and vibration damping properties. Dr Warren Grigsby is behind this project, which he says has a lot of potential. “The success of this project would create a win-win for New Zealand with fewer tyres sent to landfill and profit from a range of new export products.”

Scion is working with commercial partners on all three projects to ensure the work done in the laboratories will be commercially feasible.

Collaborations/partners: Asona, other industry partners
Investment: Ministry for the Environment