A technological breakthrough by Australian scientists has produced a solution for the world's mountains of waste truck and car tyres.

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In Australia about 70% of the estimated 11 million tyres discarded annually are still being dumped, used as landfill, or stockpiled. Tyres can now be recycled and used in shoe soles, automotive components, building products, coatings/sealants and containers for hazardous waste.

The technology has already been proven through the development of rubber ABS (Acrylonitrile-Butadiene-Styrene) composites for EcoRecycle Victoria. The composite uses 50% crumbed rubber to replace plastic, offering an economic alternative to Poly Vinyl Chloride (PVC) plastics.

Despite environmental concerns, incineration of scrap tyre rubber as a fuel source is currently the most widely used method of disposal. One example is burning tyres to fire cement kilns. Although burning a kilo of tyre rubber generates approximately 28,600 BTUs (British Thermal Units) of energy, it actually requires much higher energy (approximately 121,000 BTUs) to produce a kilo of raw rubber.

Since most common tyre recycling methods require less than 2,200 BTUs to process about a kilo of scrap tyres into clean crumb rubber, the use of crumb rubber in new products could offer considerable energy savings.

The mechanical segmenting method is highly energy efficient and is the first part of a process which incorporates downstream devulcanization* and activation phases resulting in high quality rubber powders.

The whole process will enable waste tyres to be turned back into high quality devulcanized and activated rubber powders (down to 80 - 120 mesh size) free of metal contamination for redevelopment as new products, such as new tyres and elasto-polymer based items.

Examples of applications include: Shoe soles, automotive components, tyres, non-pneumatic tyres, wheels, building products (roofing materials, insulating materials, window gaskets) coatings/sealants, containers for hazardous waste, industrial products (enclosures, conveyor belts, etc) and many more.

Find more here

Juan José Potti revealed a new method for recycling av rubber from car tires.

CRUMB RUBBER MODIFIED BITUMEN. OTHER WAY TO RECYCL CAR TIRES

Abstract

Use of grinded crumb rubber (CR) is a technology which is being used for already 40 years. However, the introduction of European Directives in Spain has generated an important awareness as far as recycling and exploitation of this residue in road construction is concerned. Probisa has a long tradition in this investigation field: studies of bituminous mixes carried out both using the dry and the humid way. Based on its experience, Probisa has developed a wide range of polymer modified bituminous binders exclusively resulting from CR. Besides the intrinsic characteristics of the binder, special attention has been paid to its viscosity to obtain bituminous mixes which can be handled under the same conditions as conventional PMB. In this way, they are coherent with the ecoefficiency objective, aimed at in all recycling processes. The paper also deals with limitations of current empirical test methods when it comes to quantifying characteristics of bituminous binders. As an alternative, a methodology based on functional behaviour tests is proposed.

Read the whole report:

http://congress.cimne.upc.es/rilem04/admin/Files/FilePaper/p330.pdf

The same report in Spanish

http://www.probisa.com/Publicaciones/showfile.aspx?id=1061