Millions of vehicles on the road today are outfitted with tires provided by a number of inventors that include Michelin, Goodyear, and Dunlop, to name a few (Bettis). Initially, simple wooden wheels served to provide transportation for vehicles and were very bumpy. Later, leather was included in the design to soften the ride. Today’s tires are categorized into types of solid rubber or the pneumatic radial tire (Continental Tire).
Charles Goodyear created the vulcanization process in 1839, which used sulfur to heat rubber and made it pliable enough to mold (Continental Tire). After vulcanization, tires were made from solid rubber and were strong.
The pneumatic rubber tire was developed by John Boyd Dunlop of Belfast, Ireland, in 1888. For the next 50 years, vehicle tires consisted of an inner tube that contained compressed air and was enclosed by an outer casing. These layers were called plys, which were made of rubberized fabric cords, and they reinforced the casing (Continental Tire). Steel-belted radial tires were initially introduced in Europe in 1948 that produced longer tread life, better steering, and less rolling resistance.
As an increasingly number of vehicles travel America’s roads, the use of tires has grown exponentially with challenges on how to best dispose of them. Estimates forecast there are more than one billion end-of-life tires generated each year throughout the world with approximately four billion unusable end-of-life tires dumped in landfills and stockpiles (LeBlanc). They are breeding grounds for mosquitoes and rodents, threaten the safety of people, and harm the surrounding environment.
International efforts are in progress to further policies to manage the disposal of used tires. Because the rubber in them is not biodegradable, old tires must be recycled and repurposed rather than simply carted off to landfills. Mounds and mounds of tires are still piled in dumps around the globe, but positive results of their recycling are being demonstrated. Magnum Recycling USA, Inc. is located northwest of Hudson, CO, at the site of the world’s biggest tire dump. This specific company has over 30 million used tires waiting for processing and plans to recycle the entire number within a few years (Leather).
Approximately one per person in the United States generates scrap tires or about 300 million per year (LeBlanc). Tire recycling, also called rubber recycling, is the process of converting end-of-life or unwanted old tires that are no longer usable due to wear or damage and can no longer be re-treaded or re-grooved (LeBlanc). In 1990, only 17 percent of old tires were recycled in 1990, 80.4 percent of old tires were recycled by 2003, according to the U.S. Environmental Protection Agency (LeBlanc).
Of the 233 million tires recycled in the United States in 2003, uses included: retreaded, 7.10%; used as a fuel, 44.70%; recycled or used in civil engineering projects, 19.40%; ground and recycled into products, 7.80%; converted into ground rubber and used in asphalt, 4.30%; and exported for use as retreads, 3.10% (LeBlanc).
Forty million tires are used every year in the U.K. with one-quarter of them being converted into retreads; one-third transported to landfills, and the rest of them being burnt. Though many governments still prefer to incinerate old tires, many more countries are moving toward recycling. The uses of the recycled rubber include carpet underlays, soles for shoes, foundations for the building of roads, and the material to resurface sports and play areas (Leader). In progressive Germany, all consumers who buy a new tire pay a minimal tax to help pay for tire recycling. Though Germany is innovative with its tire tax, it is the leader in burning waste tires, which releases an excessive amount of pollution into the atmosphere. Officials continue to seek ways to minimize this harm.
Germany utilizes tires in a number of ways, which include 1) using the tire for its originally intended purpose in an extended way; 2) designing rubber compound and tire design for maximum durability; 3) using whole scrap tires to recover energy from burning; 4) using mechanically processed tires for energy recovery; 4) altering the chemical structure of scrap tires and using the products for energy recovery; 5) storing tires for possible recovery later; and 6) disposing the tires without any current or future use (Reschner).
There are approximately twenty million scrap tires generated each year in Saudi Arabia. Methods to manage these old tires include landfill disposal, use as material for roads after crumbling the rubber, and extending the life of the tires as long as possible. A relatively new recycling process is through cryogenic fragmentation, whereby tires are shredded and cooled to below minus 80 degrees C. The components are separated by a hammer mill that pounds the chips into rubber granules that can be used for athletics tracks, carpet underlay, playground surfaces and rubberized asphalt for road surfaces (Aljaaidi, Almohanna, & Bin Jumah).
Saudi Arabia has the world’s largest Automatic Waste Collection System, but it is not
being used to its full capacity. Arab countries are not heavily industrialized and possess minimal technology for the processing of waste, especially in tire recycling. Because information on the need for waste disposal and recycle is limited, along with deficits in information management systems and monitoring processes, decision-makers cannot fully make accurate assessments on how to best dispose of scrap tires.
Officials throughout the world will continue to seek ways to effectively recycle used tires, work to protect the environment, guard the safety of its people, and utilize the used rubber in the best way possible.
- Aljaaidi, Wail M., Almohanna, Hamad M., and Bin Jumah, Abdulrahman Z. “Used Tires Recycling and Utilization in Saudi Arabia.” fac.ksu.edu.sa/sites/default/files/final_ report_.pdf. May 2014. Web. 5 May 2017.
- Bellis, Mary. “John Dunlop, Charles Goodyear and the History of Tires.” www.thoughtco.com/ john-dunlop-charles-goodyear-tires-1991641. 16 Apr. 2017. Web. 06 May 2017.
- Conserve Energy Future. “Tire Recycling.” www.conserve-energy-future.com/TireRecycling.php
2017. Web. 5 May 2017.
- Continental Tires. “The Evolution of the Tire.” http://www.continental-truck.com/truck/ company/business-unit/tirehistory. n.d. Web. 5 May 2017.
- Kal Tire. “The History of Tires.” www.kaltire.com/the-history-of-tires/. 2017. Web. 5 May 2017.
- Leather, Tony. “Seas of Rubber: The Truth About Tire Recycling.” https://recyclenation.com/2010/06/sea-rubber-truth-tire-recycling/. 15 Jun. 2010. Web. 5 May 2017.
- LeBlanc, Rick. “The Importance of Tire Recycling, Old Tires Are Being Increasingly Utilized.” www.thebalance.com/the-importance-of-tire-recycling-2878127. 31 Jan. 2016. Web. 5 May 2017.
- Reschner, Kurt. “Scrap Tire Recycling – A Summary of Prevalent Disposal and Recycling Methods.” www.entire-engineering.de/Scrap_Tire_Recycling.pdf. n.d. Web. 5 May 2017.