Waste tire disposal and waste tire recycling
Most drivers usually deal with their tires twice a year: around Easter, when it's time to switch from winter to summer tires, and in October, when it's time to arm yourself with suitable tires for snowfall and black ice. The tires that are no longer needed are usually stored by the workshops until the next season or disposed of if they are worn out. This applies to tires that fall below the legal minimum tread depth of 1,6 mm. Experts recommend not waiting that long: Summer tires should have a tread depth of at least 3 mm and winter tires should have a tread depth of at least 4 mm. Anyone who briefly estimates how many cars are on German roads already suspects what a mammoth task the disposal of used tires (used tire recycling) is. Annually fall about 600.000 tons of used tires each of which has a half-life of approximately 2.000 years.
Used tires for export and retreading
But a worn tire is by no means a case for the shredder: it is either sent to Länder exportedin which high speeds cannot be driven due to poor road conditions - African and South American countries in particular are popular buyers here - or the old tire is used after extensive test runs for the Retreading intended. Every car tire can be retreaded once and every truck tire up to three times – provided that certain basic conditions are met. In the process of Retreading first, the rest of the profile of the carcass away. The carcass is the basis of the tire. The resulting gum powder is an important raw material that is used in road construction, among other things, but also in the design of sports facilities and playgrounds. On the carcass A new rubber compound is then applied using state-of-the-art technology. The tire then gets its new profile in the curing press and, after another quality check, it goes on sale.
Two ways of scrap tire recycling
Tires that are damaged, or completely worn and for which none of the above recovery methods come into question are disposed of and go either to the thermal or to the material recycling. In the thermal recycling Tires are used as fuel in industries such as cement, pulp and power plants. This method doesn't have a very good reputation because burning car tires are more associated with pollution. In fact, old tires with a calorific value of approx. 9,0 kWh/kg and a sulfur content of approx. 1,2% are excellent sources of energy.
Rubber granules: material with a future
Not energy, but a new material is at the end of the material Recycling. To do this, the tire is roughly chopped up into palm-sized pieces with the help of rotary shears or in a two-shaft shredder, or cut lengthwise in peeling snakes and then finally ground into coarse or fine granules in several passes in so-called fine grinding plants. The components metal and textile fibers are extracted. It is a complex process because gum powder must be completely pure in order to be able to be used for its further purpose.
Sports fields that used to have a cinder track are more and more often equipped with plastic running tracks that are easy on the joints. On playgrounds and in swimming pools, the soft rubber surfaces protect children from injuries, and artificial turf is also made from the small rubber grains. Numerous other possible uses are conceivable: The granules are the basis for elastic adhesives and fillers, shoe soles, roof coverings and much more. Rubber powder is also used proportionately in road construction to make the asphalt more elastic and more resistant.
Creating new values – circular economy The NEW LIFE initiative is supported by companies and associations whose declared goal is to use recycled material from ELT (End-of-Life-Tyres) as a sustainable raw material for high-quality products with a long service life.