In the past, used tires were primarily a waste product in Ontario, thrown into landfills or shipped to areas that had recycling facilities. Now they’re a hot commodity under a program that collects and sends them to be turned into new products.
“Last year we recycled somewhere in the realm of 11 million tires,” says Andrew Horsman, executive director at Ontario Tire Stewardship (OTS), the industry-run association that administers the program.
“We have seven companies who are using (recycled tire) rubber in the manufacture of finished products, and by the end of this year we will have 10.”
Recycling starts with separating the three main components of the tire: its rubber, steel, and nylon or polyester fibre.
It’s mostly done through ambient grinding, where the tire is shredded at ambient temperature by huge metal cutters. A smaller percentage is done with a high-tech method called cryogenic grinding. The tire is cut into fist-sized pieces that are then frozen with liquid nitrogen and shattered with a hammer mill.
The steel in the tire is recycled by steel mills, while “fibre is the problem child,” Horsman says. Most of it is currently burned to run cement kilns and some is used for animal bedding, but Horsman says research is ongoing to find a use for it in molded projects.
Most of the tire is rubber and there are many markets for it. Loose shreds are used for such things as landscape mulch and sports fields, especially rubber that’s been ground cryogenically, since its unique shape resists compaction and provides better shock absorption.
Chopped rubber, called crumb, can be turned into a wide range of products including car parts, landscaping and floor tiles, door mats, roof shingles, livestock mats and carpet or floor underlay.
“All of these products are not only ‘green’ because they’re recycled, but they perform better than the products they’re replacing,” Horsman says.
“There’s a roof shingle of composite material made from recycled rubber and it’s on par with a steel roof. It’s a number of times more expensive than an asphalt shingle, but the installed warranty is 50 years and the product is recyclable at the end of its life. You’ll replace an asphalt roof three to four times before you need to replace one of these.”
Horsman says that roads built with rubberized asphalt have been successfully proven in Saskatchewan and several U.S. states, and that OTS is working to bring the product to Ontario.