Devulcanisation

University of Twente develops sustainable tyres

Environment big winner with by RecyBEM funded research

In cooperation with the University of Groningen, PhD student Sitisaiyidah Saiwari of the University of Twente, has developed a new method for recycling old tyres. This breakthrough allows that forty percent of the rubber waste can be reused in the production of new tyres, instead of the current maximum of five percent. Old tyres are therefore no waste, but a resource for new tyres. In the Netherlands we collect about eight million tyres annually of which about two-thirds is scrap. In the new recyclecyclus these old tyres can be used as raw material for new tyres. That's good for the environment. Increasingly scarce raw materials would not be lost. The research was funded entirely by RecyBEM. The technology is patented.

Re-use is better than recycling

According to Lansink's Ladder product re-use is better than recycling, incineration or even discard. "Used tyres are now recycled into products such as floor mats, soccer fields with rubber granules or traffic furniture such as rubber bumpers" said Supervisor Wilma Dierkes. "In some parts of new tyres at most five percent rubber can be used. We try to return the vulcanization, leaving forty percent can be incorporated into new tyres. A great progress."

Less loss of raw materials

In the recycling process of Saiwari only the so-called sulfur bridges are broken. The polymer, as a molecule responsible for the most critical properties of rubber, is not affected. "Of course, we continue to produce the same amount of used tyres worldwide, but far less raw materials are lost, thanks to this process. The environment is in this new process also a big winner."

Read the entire thesis: 'Post-consumer tires back into new tires, de-vulcanization and re-utilization of passenger car tires' (pdf-document, 10,5 MB).

Source: University of Twente