As the global economy advances, the demand for tires continues to grow. Each year, more than 1 billion waste tires are produced worldwide, making up approximately 2% of total waste. This surge is largely due to increasing automobile sales in both developed and developing nations. 

According to statistics from the U.S. Federal Highway Administration's Research and Technology Division, the United States generates about 280 million waste tires annually, which averages to roughly one tire per person in the country. Of these, around 30 million tires are either reused or retreaded, leaving approximately 250 million tires that need to be managed properly. Waste tires not only contribute to environmental pollution but also create significant obstacles for our circular economy. Therefore, effective tire recycling and reuse are essential to tackle these challenges.

Diverse Reuse Methods for Tires

One common approach to dealing with waste tires is retreading, where the worn tread is replaced with a new one. This process reuses about 90% of the tire's material, reducing waste and providing a degree of safety. However, for those waste tires that are unsuitable for retreading, alternative disposal methods must be employed.

Governments worldwide encourage the recycling of waste tires, especially those that are unfit for retreading. One common method involves removing the bead from the tire, cutting it, and stamping it into products such as shims or belts. By cutting tires into different sizes, we can create more recycling opportunities. Waste tires can be cut into various sizes of shreds, typically categorized as shreds (50-300 mm), chips (10-50 mm), and granules (1-10 mm). The necessary equipment will depend on the range of sizes required for production.

Applications of Tire Shreds, Chips, and Granules

Tire shreds processed by machines such as the "Super Chopper" are ideal for transporting waste tires and possess a high calorific value, often used in the cement and paper industries as a supplement to traditional fossil fuels. Additionally, tire shreds can serve as Tire Derived Aggregate (TDA) in civil engineering applications, such as lightweight fill and vibration reduction.

Tire chips can be produced from whole tires or tire shreds using shredders equipped with built-in screens. They are applicable in the same TDF uses as tire shreds but offer the added benefit of lower steel content. Tire chips are also utilized in the equestrian industry, mixed with sand or sawdust to protect the legs of horses, especially in countries like the UK, where this is a significant industry.

Rubber granules can be used in the production of rubber mats and molded products, widely employed in sports facilities and artificial turf. Moreover, recent applications for rubber granules include pyrolysis, a process in which rubber is converted into oil and solid new materials or fuels.

Recycling Metal and Textile from Waste Tires

Waste tires comprise approximately 20% steel and 10% textile material. The recaptured steel has high value, as steel manufacturers worldwide often recycle steel recovered from tire recycling plants and pay good prices, particularly when it has been cleaned of rubber and textile residue. In contrast, the recycled textile material is typically incinerated, as its high calorific value makes it an ideal additive in the cement industry.

Efficient Tire Recycling Solutions

To address the challenges of reclaiming waste tires, Harden offers a comprehensive and efficient tire recycling system. This system features a modular design, characterized by low noise, low energy consumption, high throughput, and uniform discharge particle size. 

In this system, waste tires are fed onto a conveyor belt into a double-shaft shredder for processing. The resulting tire shreds are sorted by a disc screen for size control. Tire shreds that do not meet the size requirements are returned to the shredder for secondary shredding until the desired discharge size is achieved. Ultimately, the system produces high-quality tire-derived fuel (TDF), achieving effective resource recycling.