Managing Processing Challenges Posed By Advances in New Tire Technology

When tire recyclers and stakeholders from across the tire industry gathered at the Scrap Tire Recycling Conference in Greenville, South Carolina in December 2019, changes in tire manufacturing—from new tire design technologies, to computerized tracking sensors— and their effect on tire processing and recycling took center stage.

In a session addressing Future Tire Technologies & Managing Processing Challenges, Charles Astafan, General Manager, CM Shredders presented the first-ever test conducted to look at the processing challenges new and emerging advances in tire design and manufacturing technologies pose for tire processors and recyclers.

For the pilot test project, CM partnered with the Washington, D.C.-based Scrap Tire Research Education Foundation (STREF) to select the new tires and technologies to be tested. They were: Michelin X Tweel Turf, Goodyear Wrangler All-Terrain Adventure with Kevlar, Continental ContiProContact with Continual, Pirelli P Zero and Bridgestone Driveguard.

Setting the stage, Astafan said that while new tire technology is ever evolving, recycling is not a consideration in new tire design.

Safety, tire road friction coefficient, rolling resistance fuel economy, reduced reliance on natural rubber, environmental concerns, cost and a host of other drivers factor into the engineering and design advances being employed in manufacturing today’s new tires and those of the future, he said.
Speaking to recyclers, Astafan said tires are a unique and highly engineered product, pointing out that “it’s precisely tires unique design and resilience that has created our industry”.

Today’s challenge, he said, is for the tire recycling and processing industry to evolve with these new tire designs.

For the pilot test, the five selected tires were brought to CM’s shredder equipment manufacturing and demonstration facility in Sarasota, FL. Each tire featured different design technologies and materials.

Each was processed in a separate test that involved an analysis of the components in the tire (see photos) and what effect those components would have on equipment maintenance, performance and longevity, Astafan said.

The Michelin X Tweel Turf tire is an airless radial tire with shear beam technology and poly-resin spokes inside. “Processing this tire involves first deconstructing and separating the components…there’s metal, composite material and rubber, “ Astafan said.

Pirelli’s P-Zero, a tubeless radial which can run flat, has a noise cancelling system embedded in a foam layer on the inside of the tire wall.

The Goodyear Wrangler A/T tire, a tubeless radial, manufactured with Dupont™ Kevlar®, has 30% more steel and Durawall™ technology that uses lots of fiber, Astafan said. The tightly woven Kevlar, steel, and fiber in the tire rubber pose new challenges for processors, he said.

The Bridgestone Driveguard system which adds a silica seal in the tread interior and NanoPro-Tech reinforced sidewalls presents another slightly different challenge for processors.

Continental’s Contiseal™ has a gum-like, sticky substance applied on the inner wall, which Astafan said makes it almost impossible to shred because the sticky liner would gum up the knives and shredder mechanisms making it a “no-go” for processors.

Looking ahead, Astafan said new front-end separation systems and methods will be key once these new technology tires enter the recycling stream.

Processors will need to have systems or programs to identify the different types of tires and separate them from conventional mainstream tires prior to processing.

Today’s computer modeling and new testing methods will help the industry adapt more quickly than in the past. Most importantly, he said, manufacturers and recyclers will need to collaborate and communicate as new technologies continue to evolve.

© Scrap Tire News, February 2020