Last year, about 84000 tons of waste tires in Germany went missing, accounting for 16.1% of the total

The gap in the flow of waste tires has attracted industry attention. According to data released by the German Rubber Industry Association (WDK), about 84000 tons of scrap tires (ELT) in Germany went missing last year, accounting for 16.1% of the total. The association is concerned about the final destination of this batch of waste tires. Scrap tires are the last link in the tire and rubber industry chain. According to the normal recycling and disposal path, waste tires usually enter channels such as refurbishment, rubber powder preparation, recycled rubber, pyrolysis, or energy recovery. The gap disclosed this time means that a considerable portion of waste tires have not entered a statistically traceable disposal system.

Inspiration for rubber additives and formulation

The flow of waste tires is unclear, which appears to be a problem of recycling statistics, but is closely related to the material design of the entire lifecycle of tires.

. The formula system of tires determines their difficulty in recycling and reuse value: the more stable the cross-linking network formed by the vulcanization system, the more difficult it is to desulfurize and reprocess the regenerated rubber; The selection of reinforcing fillers affects the subsequent application performance of rubber powder. Reinforcing fillers represented by white carbon black are widely used in low rolling resistance tires, and their interface bonding with the rubber matrix also affects the crushing and redispersion behavior of waste rubber. From a material perspective, the amount and type of anti-aging agents and antioxidants are related to the degree of aging of tires during their service life, and indirectly affect the rubber state of waste tires when they enter the recycling process. Rubber materials with severe aging experience greater performance loss and reduced reuse value during the preparation of rubber powder or recycled rubber, which to some extent weakens the economic attractiveness of formal recycling channels.

Linkage between Recycling Chain and Formula Design

The association’s concern about the destination of waste tires reminds the tire and rubber industry to consider traceability and material recyclability on an equal footing.

. For tire formula design, while meeting performance requirements such as wear resistance, wet skid resistance, and rolling resistance, the selection of vulcanization system, the combination of reinforcing fillers, and the optimization of the dosage of anti-aging agents and antioxidants will all affect the disposal path of tires after scrapping. The larger the statistical gap in the recycling process, the more it is necessary to improve the usability of waste rubber from the formula source, so that the formal recycling system has stronger processing capacity and economy. At present, public information only involves the quantity and proportion of waste tires, and the specific composition and flow of the gap have not been disclosed. The changes in the regulatory and statistical standards for subsequent recycling are worth the continuous attention of tire and rubber material practitioners.

Information source:Germany: Almost one in six ELTs unaccounted for， Organized by Herun Chemical.