Innovation in Tire Recycling

Genan Inc. turns scrap tires into new materials

In tire recycling, all innovative ideas start out as a whole tire. For tire recycler, Genan Inc. nothing is truer.

Genan’s recycling technology, developed by Genan A/S, Viborg, Denmark, dates back to the 1990s. Its scrap tire recycling concept is unique and has been continuously developed and shaped through practical experience focused on energy reduction, process optimization, output fraction purification and reducing maintenance costs. The technology is fully automated requiring only three employees to supervise the process – plus one maintenance technician per shift. To ensure that the output is uniform and of a high quality, the tires are not touched by human hands throughout the process.

Six Genan plants around the globe, including a U.S. facility, use this unique mechanical tire recycling technology with an annual production capacity of more than 400,000 tons of tires.

Genan’s Houston, Texas plant takes in all types of tires – from cars, vans and trucks – and in a highly technological production process separates them into their original elements: rubber, steel and textile fibers. The output consists of 75 percent rubber powder and granulate, 15 percent steel and 10 percent textile fibers.
“At Genan, we believe that true recycling requires processing at a level where the output can substitute virgin raw material,” CEO Thomas Boehme said.

Imbued with the same culture of innovation that has defined and driven its parent company in Viborg, Denmark for nearly 30 years, Genan’s U.S. operation strives to repurpose every part of the tire into useful products and applications.

“It’s all about adding value to a product that has already been used,” Sales Director Christian Fenger said.

To that end, Genan manufactures high quality products derived from scrap tires, including granulates in six sizes ranging from GENAN FINE (10-20 mesh) to GENAN ULTRA COARSE rubber granulate between 2 and 6 mm, color-coated infill, rubber powder, pellets, steel and textile.

Among its recent innovations, Genan launched the GENAN SAFE pellets in 2017 – made from 20 mesh rubber powder from end-of-life tires. Genan rubber pellets are ideal for shock absorbing playground base layers, offering a number of advantages, Fenger said.

“They mimic many of the characteristics of buffings – but are more uniform in shape and have less surface area, resulting in a base layer with low bulk density, improved elasticity and minimum compaction,” he said.

Pellets are manufactured with a specific diameter and cut off to a specific length. The diameter of a GENAN SAFE 5 pellet is Ø4.2 mm, and pellets are 5 mm long. Field and laboratory testing has shown particularly good results with pellets this size, Genan said.

Compared to traditional base layers made with granulate, base layers made with GENAN SAFE pellets require less material. Material savings may be up to 30 percent – for rubber as well as binder, Fenger said.

Also, when pellets are laid out, cavities inevitably arise, creating excellent water permeability and assuring safe, dry surfaces.

In tests of playground surfaces with an approved fall height of 3 m, surfaces with base layers made with GENAN SAFE pellets had significantly better HIC results than surfaces with base layers made with traditional granulate.

GENAN SAFE pellets readily mix with polyurethane binder, producing a flowable mix that installs with minimum compaction. The pellets are self-leveling and can be easily leveled manually as well as with a paver, saving installation time and cost, Fenger said.

For sports fields, Genan’s recycled rubber granulates are used to create a shock absorbing sublayer underneath the artificial turf carpet.

The sublayer (e-layer) is made of coarse rubber granulate and polyurethane binder and can either be built in-situ – where rubber granules are mixed with 8-12 percent polyurethane binder – or made of pre-fabricated rubber mats. In both applications, Genan high-quality rubber granulate creates a highly shock absorbing, even, level surface under the turf, accounting for pile height and uneven field elevations.

“This is especially important and cost saving when re-turfing the field,” Fenger said. Once the old turf is removed, new turf can be installed directly, eliminating the need for additional field preparation or maintenance, Fenger explained.

For synthetic turf infill, Genan created GENAN COATED INFILL, a color-coated, new alternative to conventional, black rubber granulate. Genan’s infill product comes in two different colors: DEEP

GREEN and EARTH BROWN. The infill granules are GENAN FINE/MIX particles between 0.8 and 3.0 mm in size, coated with inert, non-toxic pigment and polyurethane binder. Because the infill is coated – not dyed – the infill won’t fade or run, assuring longer lasting performance over traditional infill. Although yet to be tested in practice, color-coated infill material might even have a cooling effect on synthetic turf fields.

Fenger credits Genan’s Innovation team with leading the development of a new product application for tire derived fiber. Researchers at Genan’s Viborg plant have been working with an industrial partner to develop the application and are in the final stages of completing a test installation of a new mat product that uses the fiber from tires in its construction.

Commenting on the project, Genan CEO Boehme said that partnerships are an important part of the company’s business growth strategy. “Partnerships and collaboration at all the Genan plants have helped the company reach new markets and increase customer loyalty,” he said.

At the Houston facility, Genan partnered with Liberty Tire Recycling to bolster its tire intake, while building a relationship with nearby Northwest Rubber to supply the recycled rubber products manufacturer with rubber powder feedstock has allowed Genan to grow its customer base and improve business, Boehme said.

“We continue to look for new product ideas and ways to improve our existing products and operations,” he said. “It’s in our DNA to strive for sustainable excellence, to get better every day at every stage of our processes from scrap tire intake to clean, high-quality output – and improve year on year to assure that zero percent of the tire goes to waste.”

© Scrap Tire News, July 2020