Conti ramping up use of recycled rubber in new tires

WATERLOO, Ontario — Continental A.G. is using a recycled rubber material produced by Tyromer Inc. using a devulcanization process in the production of new tires, according to the Waterloo-based company.

In business since 2009, Waterloo-based Tyromer has patented a rubber devulcanization process that it licenses to third parties, which then sell the material to end customers.

In the case with Continental, however, Tyromer is supplying the tire maker directly from demonstration facilities it operates in Arnhem, Netherlands, and Waterloo to factories in Europe and Asia.

The companies did not elaborate on which tire line or lines are being built with the recycled material, but products made with materials are expected to be sold commercially in 2023.

Separately, Continental unveiled a concept passenger tire, dubbed GreenConcept, in late 2021 that it claimed was both measurably lighter and more sustainable than comparable current-generation tires.

Conti said at that time up to half of the GreenConcept's material content by weight is made of "traceable, renewable and recycled materials," including 35% renewable raw materials such as dandelion-latex-based natural rubber, silicate from the ashes of rice husks and various vegetable oils and resins.

Tyromer was formed using an open innovation business model to allow it to collaborate with tire industry leaders, and the company said it has been working with Continental for several years to develop technology to allow rubber derived from end-of-life tires to be reused in the production of new tires.

"We could never have done it alone," Tyromer CEO Sam Visaisouk said. "Our collaboration with Continental Tires has taught us lessons in quality, reliability and consistency, among many others. We are grateful for the support and the guidance to tailor the specifications of our recycled rubber material according to Continental's specific needs."

Tyromer said TDP is made through a carbon dioxide-assisted thermo-mechanical continuous extrusion process. Crumb rubber, free of metal and other contamination in the size range of ~20 mesh is used as feedstock.

Tyromer claims TDP is superior to other recycled rubber materials because the process uses no devulcanization chemicals or chemical solvents. When running continuously the conversion is essentially 100% with no waste by-product.

Continental described Tyromer as a "trusted partner" in supplying it with recycled rubber material, according to Andreas Topp, head of materials and process development and industrialization at Continental.

"At Continental, we focus since many years on technologies that generate high-quality feedstock derived from end-of-life tires to produce new tires," Topp said in a statement provided by Tyromer.

"Our goal is to gradually use 100% sustainably produced materials in our tire products by 2050 at the latest."

Tire-to-tire recycling "represents in many cases the most direct and energy-efficient way to reuse what is still largely considered and treated as a waste," Tyromer said in a prepared statement.

The material Tyromer is supplying Conti, dubbed TDP, is a master batch produced via environmentally sustainable, non-chemical extruder devulcanization of end-of-life tire rubber that it claims reduces carbon dioxide emissions from tire rubber compounds by over 90%.

In some cases, Tyromer said a drop-in replacement of 20% produces surprisingly good results. In other cases, compound optimization is needed.

Because TDP(B) is made from truck tread material, which contains natural rubber, synthetic rubber, carbon black, etc., Tyromer said it is suited for use in tread compounds.

Tyromer said that tire rubber compound generates over 80% of the CO2 emissions from raw material production for a tire. Replacing virgin rubber with tire-derived polymer can cut those emissions by 90%, Tyromer claims.