How Tires Are Recycled
Rubber products, like tires, are designed to be long-lasting, providing consumers with valuable, cost-effective goods. In fact, tire manufacturers consistently refine the composition of their products to last even longer. The current tire composition—divided between natural rubber, artificial rubber, filler, and fiber steel—has enabled tires to last up to 60,000 miles. However, because tires are so durable, they can be difficult to dispose of responsibly when they reach the end of their usable life—that's where recycling comes in.
The most popular form of tire processing in the United States uses a mechanical process—sorting, grinding, and shredding—as follows
Collection
First, used tires are collected from tire retailers, automotive shops, tire disposal centers, or from customers directly through pick-up events in local communities across the country.
Primary shred
One of the biggest challenges of managing tires is their size—they take up a lot of space! This step shreds tires into four- to six-inch pieces.
Secondary shred
Next, the chunks are shredded into even smaller pieces, between one to two inches in size.
Remove wire
Throughout the process, high-powered magnets, situated above a conveyor belt, pull the steel wire out of the tires. This steel wire is then collected and sent to steel mills for recycling—another way in which tire recycling contributes to the circular economy.
Remove fiber
In addition to rubber and steel, tires include fiber textiles that provide dimensional stability and support the vehicle's weight. This fiber is removed using air systems and is another component that can be recycled. Processed rubber is then transferred in large “super sacks” that are recycled as well!
Determine the end use!
Different end-uses for recycled rubber each require different size granulates. For some products, like those that will use crumb rubber, the rubber will be ground down into small pieces, ¾ of an inch and smaller. For other products, like rubber-modified asphalt, further processing of the rubber is needed to reduce the size of the granulates from 4.2 mm to 2.0 mm.
When tires reach the end of their life on the road, their life as new products is just beginning. Through these techniques, the U.S. diverts millions of tons of waste from landfills every year. As of 2021, 71% of scrap tires were recycled, some 3,580 million tons, one of the highest recycling rates of any commodity. Through a few simple steps, we are able to turn tires into new innovative products that can, for example, make our roads last longer through rubber-modified asphalt, our playgrounds and playing surfaces safer through poured-in-place rubber, and our communities quieter through rubber damping pads, along with many other uses!