Waste rubber can be converted into quality products

Pioneering new research is set to upset the standard paradigm of downcycling, and as a result, high-quality new plastics from old plastics will soon be a possibility. This breakthrough is made possible thanks to a new kind of material: an environmentally friendly material mix called EPMT. This research team now hopes to upgrade this waste transformation, and has already entered talks with private enterprises to bring their innovation to commercial fruition.

Every year around the world, up to 22 million tonnes of rubber are processed, and a large portion of these goes into the production of vehicle tires. Once the products reach the end of their useful life, they typically land up in the incinerator. In a best-case scenario, the waste rubber is recycled into secondary products. Ground to powder, the rubber residues can be found, for example, in the floor coverings used at sports arenas and playgrounds, and in doormats. But until now, the appropriate techniques for producing high-quality materials from these recyclables did not exist.

Researchers at the Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT in Oberhausen have now succeeded in optimising the recycling of rubber waste materials. They have developed a material that can be processed into high-quality products, like wheel and splashguard covers, handles, knobs and steerable castors.

Their breakthrough has already garnered commercial interest. In the ‘Re-use a Shoe’ project, sports gear maker Nike has been collecting used sneakers for some time. The soles of these old sneakers are recycled under the label ‘Nike Grind’ and are reprocessed as filler material for sports arenas and running track surfaces.

The ‘EPMT compound is an innovative breakthrough in more ways than one. The crushing of rubber waste is more environmentally friendly and resource-efficient than producing new thermoplastic rubber products – an important aspect in view of the rising costs of energy and raw materials. ‘EPMT may contain up to 80 per cent residual rubber; only 20 per cent is made up by the thermoplastics,’ says Wack. EPMT can be easily processed in injection mouldings and extrusion machines, and in turn, these products are themselves recyclable.

Altogether, three basic recipes have been developed that collectively can be processed on the large technical production machines. The researchers are capable of producing 100 kilograms to 350 kilograms of EPMT per hour. Spurred on by this success, Wack and his colleagues have founded Ruhr Compounds GmbH. In addition to the production and the sale of EPMT materials, this Fraunhofer commercial spin-off offers custom-made service packages: ‘We determine which of the customer’s materials can be replaced by EPMT, develop customised recipes and also take into account the settings required at our customers’ industrial facilities,’ says the scientist.