May 11, 2009 A new method of recycling old tires to produce high-quality rubber powders for making new rubber products is being developed in Australia. Its developers say it is energy-efficient, economically viable and environmentally responsible, and they hope it will result in 50 per cent more tires being recycled.

CSIRO and VRTEK are working together on a proof of concept and prototype that cuts old tires into specific segments for reuse.

Crucially, this new process enables tires to be recycled without metal contamination. In the past, this has been one of the main reasons for the low number of tires being recycled.

CSIRO materials science and engineering scientist, who is leading the development team, Barrie Finnin says, “This is a very positive first step in a three-stage process.”

“The next two stages will involve devulcanisation and activation of rubber to produce the resultant high-quality rubber powders.”

The rubber powders, which will be down to 80–120 mesh size, could be used to produce new tires, elasto-polymer-based rubber products, industrial insulation, road pavement, industrial and domestic flooring or geo-textiles for retaining walls and embankments.

VR TEK managing director Michael Vainer says that “not only is there commercial potential for all these new products, but also, recycling rubber is a cheaper and more energy-efficient option than producing virgin materials.”

Tires are made to last a long time and are almost indestructible, yet about a billion of them are discarded worldwide each year. Disposal typically involves shredding, burning or dumping in landfill, all of which can lead to health and environmental problems such as toxic fires, leaching of chemicals into the soil and creating breeding grounds for vermin and pests.

With the growing affordability and popularity of cars, especially in countries such as India and China, global demand for rubber far exceeds supply, making the need for an economical and environmentally friendly recycling solution, such as this, all the more critical.

Karen Sprey