Goodyear has tyre re-use system, but…
Goodyear has tyre re-use system, but…
WITH Goodyear producing over 150m tyres a year – and others such as Michelin, Pirelli and Continental churning out equally vast numbers – it is little wonder that scrap tyre disposal has become a big problem.
In North America alone there is estimated to be 800m scrap tyres waiting to be processed.
Disposal systems include burning in power stations and burying in landfill sites, but the aim of the industry has always been to retrieve the rubber for reuse.
Goodyear believes it has developed such a system; not the first, it says, but the first commercially viable one. The problem lies in the vulcanisation process, which makes tyre rubber withstand heat, stress and strain.
Charles Goodyear mixed and baked sulphur together in 1839 to create these requirements. Reversing the process so the rubber, sulphur and other constituents could be retrieved has been a challenge for decades.
"It is like trying to extract eggs, flour and sugar from a baked cake," says Goodyears Larry Hunt, co-inventor of the new system.
"A number of devulcanisation techniques have been developed over the years, but none have been commercially viable," he says.
"This new process developed at our Akron, Ohio, plant appears to offer considerably higher recovery rates than earlier attempts and could ultimately reduce the amount of petroleum and natural rubber needed to make rubber goods."
Initial tests are reported to have resulted in a 40% recovery of the raw polymer with its structure essentially preserved, says Goodyear. Process improvements are expected to achieve an 80% recovery level.
The pilot scheme has only produced small amounts of retrieved polymer. If the process is adopted on a large scale, it could provide an environmentally accepted method for the disposal of many millions of scrap tyres.