Recycled Tires Level the Playing Field

Every year, more than 290 million scrap tires are generated in the United States alone. As more and more of these scrap tires are recycled, innovative applications for crumb rubber products seem to be springing up all over.

Recycled tires have been used with great success in construction, providing fill material for the manufacture of various asphalt, roofing and flooring products. But today, recycled tires are turning up in a most unusual place - on the playing fields of sports venues across the country.

Artificial turf has been around for about 35 years. In an age of domed stadiums and more indoor sports facilities, a natural grass playing surface has obvious limitations. It's tough to grow grass where the sun doesn't shine.

But new synthetic fibers, combined with new infill and new installation techniques have improved synthetic turf considerably. Today's turf is more durable, more resilient and more grass-like than ever before. Synthetic turf has considerable advantages over its natural counterpart, too. Reduced maintenance costs, lower water use, no mowing, no mud…the list goes on. Synthetic playing surfaces don't require time to "recover" between events the way natural grass does either, enabling facilities to schedule more closely and enjoy much greater utility from their investments than with natural grass. As a result, these new surfaces are becoming increasingly more popular for both indoor and outdoor sports facilities.

At the heart of this success are recycled tires…literally. Between the fibers, or blades of synthetic grass in most new turfs is a fine crumb rubber fill derived from recycled auto and truck tires. The crumb rubber infill provides stability for the surface and cushion for the players while keeping a significant number of scrap tires out of our nation's landfills. The average playing surface, say a football field, typically requires between 20,000 and 40,000 scrap tires to yield enough infill to properly treat the playing surface. It is estimated that more than 500 new surfaces featuring recycled crumb rubber have already been installed.

While today's new synthetic fields offer a host of economic benefits, they also address a major concern of old-style artificial turf - injuries, specifically - knee injuries. There are two kinds of leg injuries common with old-style artificial turf. Players would often plant a foot that sticks to the turf while the body rotates, resulting in dislocations, damaged connective tissue or broken bones. The other common injury on old-style turf occurs when a player lands awkwardly on the hard surface and all of the pressure goes directly to the knee, which gives way. This track record for injuries prompted a gradual return to natural grass surfaces in many stadiums where earlier artificial turfs were installed.

How do the latest synthetic turfs work? According to Darren Gill, marketing coordinator for FieldTurf International, Inc., originator of these new surfaces, "We designed a system to look, feel and play like real grass, without any of the disadvantages. It begins with a specially developed synthetic grass-like fiber about 2.5 inches long. The airspace between the blades is then filled with a blend of silica sand and recycled crumb rubber product until the turf is about three quarters of an inch long. The recycled tire infill is a form of synthetic dirt that gives the turf many of the qualities that players and facility managers really appreciate," he said. Some systems use 100% rubber infill from recycled tires.

Mark Nicholls, president of Sportexe, Inc., points out, "Fields with a blend of crumb rubber and sand use an ambient crumb product which is produced by grinding and reduction of the recycled rubber. The granules are rough and irregular in shape, which helps hold the sand in place. Fields with 100% rubber infill use a cryogenic crumb. The recycled rubber chips are frozen, then shattered, producing crumb rubber granules that are very uniform and round in shape," he said. Both methods produce great results.

Recent studies indicate injuries on the new surface have been reduced as well. Cleats don't become entangled in the newer surface the way they used to. "It's a softer, much more forgiving surface, and a lot better than the original artificial turfs," said Brant Smith, general manager of the Soccer Centre, Inc. in Maumee, Ohio. "You can play an entire game without feeling beat up. Players tell me they really like it," he added.

While it's too soon to observe the long-term effects on injuries from today's synthetic fields, players are enthusiastic about its performance, and optimistic about its future. Many NFL franchises, Major League Baseball parks, universities and international soccer (football) stadiums have already installed new, "infilled" synthetic playing fields.

Maintenance for these new fields is minimal. Darren Gill points out, "Once the surface is installed, it seldom needs additional infill. FieldTurf supplies a grooming machine with every installation. The groomer is towed over the field behind a lawn tractor. It rakes the surface, restoring all of the original qualities and ensures that no contaminants become mixed with the infill," he said. As part of the grooming process, groundskeepers can "stripe" the field for that perfectly manicured look - just like real grass.

Good News for Natural Grass

Recycled tire infill has been used successfully in some field sports facilities without the synthetic fiber carpet. Applied directly over natural grass, crumb rubber provides a softer playing surface and reduces compaction of the soil. Compaction destroys roots and ultimately kills grass.

Nebraska City, Nebraska based Entire Recycling provides a complete service that delivers and applies the properly sized crumb rubber infill directly to customers' athletic fields. Jim Gerking, company president said, "We contract with schools or other organizations to provide a turn-key service. Depending on the condition of the present field and even the soil makeup of the field, the rate of crumb rubber used per square foot may vary. We recommend that customers don't change any of their present field care procedures. You do not need to do anything special to the field after the crumb rubber is applied. Most users find less irrigation is needed," he said. Business has been so good, the company plans to open an expanded facility in nearby Phelps City, Missouri. Recycled tires are in widespread use for applications such as running tracks, playground surfacing, equestrian stalls and landscaping mulch with hundreds of potential new uses currently being developed.