It is very difficult to properly dispose of rubber tires from vehicles, since these rubber objects contain a significant amount of void space. This means landfills will fill up very quickly, and the empty space can harbor vermin, allow mosquito breeding, and even trap methane gas. A tire recycling plant helps solve this problem by breaking down old tires and making them into usable materials. Tires can be delivered to a tire recycling plant, usually in bundles created with a compactor, and then broken down into small pieces known as crumb rubber.
This crumb rubber can be repurposed in many ways, including use in hot asphalt, the laying of basketball courts or tennis courts, and even manufacturing shoe soles. These processes do not take place at the tire recycling plant, however; instead, this facility will be used to break down old tires and transform them into usable crumb rubber. The facility will also have packaging capabilities, which means the particulate crumb rubber can be compacted into large bales that are usually wrapped in plastic. These bales make the transport of the particulate crumb rubber much safer and easier; the bales can also be stored easily at the tire recycling plant.
Many tires contain metal, and in many cases this metal needs to be separated from the rubber before the rubber can be reused effectively. Many tire recycling plant locations will have machinery to accomplish this, though in some cases the metal is left inside the rubber. Trace metals inside the rubber can be dangerous when the crumb rubber is used as fill in soil, since chemicals in the metal and the vulcanized rubber, can leach into the soil, leading to contamination.
If a tire is in good enough condition to be re-treaded, it may be sorted and sent to a tire manufacturer with the capabilities to re-tread the tire. A tire recycling plant usually won't have the machinery or manpower to do this job onsite. Most machines in a tire recycling plant are designed to break down the tires; shredders, for example, are machines that feature large hoppers into which tires can be loaded. Rotating blades will then shred the large tires into the crumb rubber. The size of the particles will generally vary depending on how the machine is set up, thereby allowing the machine to create different size particles depending on the intended application.