End-of-life vehicles (ELV’s) are motor vehicles that are defined as waste by the Waste Directive. All of the components are classed as waste as well, including the tyres, which represent approximately 3.5% of the weight of an ELV. Considering 8 million vehicles are disposed of and 18 million part-worn tyres are disposed of, a total of 50 million tyres need to be dealt with each year. This report will discuss the current methods of recycling and reusing tyres and also the future techniques to be introduced to the industry. However, I will begin by introducing the history of recycling tyres.
Recycling of rubber began in the early 1800’s, when the industrial manufacture of rubber began. Rubber scraps were ground into shreds and crushed into large blocks that could be reused. In the early 20th Century rubber costs were relatively high, making recycling essential for rubber to be affordable. At this time 50% of rubber content was being recycled, however this was to be short lived due to the introduction of synthetic rubber manufacturing. The influx was caused by the demand for tyres in World War II and cheap oil imports reduced manufacturing costs, which dropped tyre and rubber recycling to just 20%.
Recycling of tyres has encountered many obstacles; in 1943 vulcanisation of rubber was invented and patented by Charles Goodyear. Vulcanisation links all the rubber molecules together into one big molecule, which weather proofs the rubber yet is ultimately difficult to re-separate and recycle. Vulcanised rubber can be reused but only if it is combined with natural rubber, which was in low demand due to the new and lower priced synthetic rubber. In the 1960’s tyre recycling became harder due to the invention of steel-belted radial tyres. The rubber in the tyres could still be ground and shredded, however the steel needed to be removed at this stage, which was expensive and required invention.
Since 2003, tyre recycling has been on the up thanks to EU legislation, banning the disposal of whole tyres in landfills. In 2006, the legislation will extend to banning the disposal of shredded tyres and by 2007 tyres as liquid waste will be banned as well. Tyres are being prohibited from landfill sites because of the potential catastrophic problems they cause. Tyres can rise to the surface of a landfill site by trapping methane within their void space. This causes land instability due to erratic soil settlement, making land reclamation difficult and dangerous. Rubber materials also contain certain chemicals that have unknown effects in the long term, rendering the future site as potentially hazardous.
However, this law does not include the disposal of bicycle tyres or tyres with an outside diameter of above 1400mm. These tyres are excepted because they do not cause the same dangerous problems that regular vehicle tyres do. The EU came up with this legislation to help reduce the tonnage of waste sent to landfill in each of its member states. The UK adopted this law as its landfill directive in 2003, dramatically changing the emphasis on tyre recycling in the UK. It has placed encouragement on tyre manufacturers to take tyre recycling into account when producing new tyres. Leading manufacturers Dunlop and Michelin are committed to developing alternative recycling processes and energy recovery. Unless exempted by standards legislation, the vast majority of our tyres are suitable for re-treading. Also, all our truck and bus tyres can be re-grooved, which allows us to extend a truck tyre’s life to more than a million kilometres.
Also exempt from the landfill directive are tyres used as a landfill engineering purpose. The tyres being banned from landfill sites cannot cause their possible problems if they are used safely to construct drainage systems within the landfill sites. Landfill engineering is fast becoming a popular method of recycling used...