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Rubber flooring was once relegated to general utilitarian duties. Available mostly in plain grays and browns, it was hidden in back stairways, back hallways and utility rooms. Its durability and performance are exceptional, but it just wasn't "pretty" enough for the public areas of commercial buildings. And the typical round-disc surface profiles weren't conducive to rolling carts or chairs.
Much has changed in the last decade. Manufacturers have introduced smoother profiles in fashionable colors and designs that coordinate with other interior materials and finishes—and rubber flooring's acceptance has grown exponentially, particularly in critical applications like health care and education, but also in many other high-use commercial environments.
The reasons for its growing popularity are numerous. Rubber floors:
- Make seamless installations possible—perfect for environments where bacteria and infections are a threat, and for spaces that require frequent and intensive cleaning
- Can be manufactured with antimicrobial properties
- Have excellent slip resistance, exceeding ADA recommendations for slip resistance on flat surfaces
- Offer a resilient surface that reduces the potential for injury in the event of a fall, and minimizes leg and back fatigue
- Are dimensionally stable
- Are very sound absorbent
- Resist heavy impact loads
- Resist cigarette burns and chemical spills
- Are easy to maintain (no waxing required)
- Have natural resistance to damage from gouges and scuffs because of their homogeneous construction
- Have superior color uniformity compared to other materials
- Offer unlimited custom graphic and design options
- Create no health or environmental concerns
Some rubber flooring producers have earned FloorScore certification. The FloorScore program, developed by the Resilient Floor Covering Institute (RFCI) in conjunction with Scientific Certification Systems (SCS), tests and certifies flooring products for compliance with indoor air quality emission requirements adopted nationwide. A flooring product bearing the FloorScore seal has been independently certified by SCS to comply with the volatile organic compound (VOC) emissions criteria of the California Section 01350 standard.
These flooring products qualify for use in high-performance schools and office buildings. Products with the FloorScore seal have passed a third-party certification process and are recognized as contributing to good indoor air quality in order to protect human health. Products bearing the FloorScore label also meet the indoor air emissions criteria of the Collaborative for High Performance Schools (CHPS), the LEED Green Building Rating System, and the Green Guide for Health Care.
For many, rubber flooring's biggest selling point is probably its lifetime maintenance cost—the lowest of all major flooring options (see sidebar). It can last and look good for a very, very long time, which is why it often replaces or is specified over VCT, vinyl sheet goods and linoleum. Regular cleaning with an auto scrubber will bring out rubber's natural sheen without the need for stripping and waxing. Couple this with the material's inherent resistance to damage, and you've got a floor that's much more likely to "ugly out" long before it wears out.
This level of durability was once a mixed blessing. When a rubber floor was finally removed, there were no viable recycling or reuse options for the old flooring material, primarily because rubber floors are generally glued down with very strong adhesives that are difficult to remove from the material when it's pulled up—and the presence of these adhesives on the material limits reuse options. Landfilling used to be the only option.
After years of research, however, a method for breaking down and reusing rubbers floors has finally been developed, adding to the material's already extensive LEED advantages (see sidebar on page 71). And a growing market is eagerly embracing these old flooring materials.
WHAT IS RUBBERNatural rubber is an elastic hydrocarbon polymer, or elastomer. It is derived from latex found in the sap of some plants, where it helps defend them against small insects. Latex also coagulates when exposed to air.
Most latex is harvested from plantation-grown pará rubber trees (Hevea brasiliensis) when they are five to six years old. Rubber trees must be "tapped" every seven to nine years, or they will stop producing latex. The trees are not destroyed or harmed in the process. Natural latex rubber is used in products such as latex gloves and balloons. Rubber trees will not grow in North America, so most of our rubber products are made from synthetic rubber.
The most widely used synthetic rubber copolymer is made from styrene and butadiene. Styrene-butadiene rubber (SBR) was developed in Germany prior to World War II, but became prevalent in the United States during the war as a replacement for natural rubber supplies no longer available from the Far East. Vulcanized SBR offers superior abrasion resistance and aging stability in the presence of certain additives.
To create more durable products, the molecular structure of SBR is set through vulcanization—the application of heat, pressure and steam. Vulcanized rubber is less sticky and therefore easier to work with in manufacturing than rarubber, and can be engineered for specific mechanical properties for products such as hoses and shoe soles. Hard vulcanized rubber, known as ebonite, has higher styrene content and is used to make bowling balls and the mouthpieces for woodwind instruments like saxophones and clarinets.
Rubber flooring is commonly manufactured by vulcanizing SBR. Vulcanized rubber flooring provides superior durability without losing resiliency when compared with other polymeric/elastomeric flooring technologies.
Because of its molecular structure, vulcanized rubber flooring cannot be melted down to mold a neproduct, which adds significant challenges to recycling compared to other manmade hydrocarbon flooring materials. Some manufacturers will chip down old materials and reintroduce binders to create neflooring products; but until recently that was the only option—and demand was limited by the resulting "speckled" designs.
CRACKING THE RECYCLING CODERubber flooring offers one of the lowest life-cycle costs along with a reduced environmental impact. In recent years, recycled vulcanized SBR has been increasingly popular in municipal landscaping mulches, playground surfacing, rubber crumb (or "sand") for athletic fields, and in other applications such as pavers and edgings. Much of this material was made from tires. Rubber flooring had been left on the sidelines because of the complications adhesives introduced to the grinding and chopping process … until now.
An innovative new chopping and shredding method has been engineered that allows rubber flooring to be processed into mulch, soft "stone," and rubber crumbs for use in landscaping, athletic fields and playground applications.
Designers and contractors accustomed to the job site recycling programs instituted by the carpeting industry have been waiting for other product categories to come up to speed. Thanks to an innovative partnership between the supplier and the recycler, some rubber flooring manufacturers can now offer the same cost, logistical and environmental advantages.
Here's hothe rubber flooring recycling program works:
- Product must be removed from the existing installation and prepared for return shipment.
- No scraping of the adhesive from the backside is needed.
- Product should be stacked on a pallet as neatly as possible or collected in a Gaylord (large cardboard) container. Containers and pallets are provided by the manufacturer in the program.
- Shipping preparation:
- Be sure to shrink wrap, strap or band the skid or container securely for shipping.
- Product should be kept dry prior to shipping.
- The skid must be free of other construction or demolition debris.
- Return of product:
- Contact the recycling company to arrange for the pickup of the product.
- Secure the freight payment method in advance.
- Include the project name, location and contact information so the program operator can provide you with a letter stating the amount of product diverted from landfills for your records.
Rubber flooring samples can also be returned to suppliers' vendor partners for reuse in other products. Program suppliers may, on request, test samples of a floor being removed to ensure it can be recycled.
Once at the recycler, the old flooring is prepared, chopped and shredded. If desired, a special EPA-approved adherent paint can be applied in a range of colors to the chopped rubber to give it uniformity, although consumers tend to prefer a mix of the flooring's original colors. Incoming material can be sorted by color before being recycled for specific color combinations.
The machinery used by the recycler is custom engineered to operate more efficiently—and less expensively—than other rubber flooring chopping and shredding equipment on the market. Special blades had to be developed because, surprisingly, rubber dulls tooling five times faster than grinding concrete. Depending on the durometer or hardness of the rubber, friction in the process can raise temperatures to 300 degrees within five minutes.
In the year since the industry's first rubber flooring recycling program began, more than 1,000 tons of material—both removed flooring and factory scrap—have been diverted from landfills.
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A NEW AFTERLIFE FOR RUBBER FLOORSRubber flooring that has been converted to playground mulch creates a safer play area, and keeps thousands of tons of rubber out of landfills. It conforms to U.S. Consumer Product Safety Commission guidelines, and has earned ADA approval.
As landscaping mulch, recycled rubber flooring is considered a safe compound and is harmless to plants. It also lasts much longer than organic mulch materials. Compared to landscaping rock, chopped rubber delivers much more volume with less than half the weight, making it less expensive to haul (and requiring less labor to disperse).
Recycled rubber's role in athletic fields is to aerate artificial turf. That sand-like substance you see bouncing up around football players as they run? That's rubber recycled into a crumb form. Athletic shoemakers have even developed special shoe designs and sole compounds for maximum performance on artificial turf with rubber crumb.
Recycled rubber flooring is being combined with rebinders to make pavers and even Olympic weights. Larger rubber "stones" are also being used in concrete blocks, rather than real stones, to give them better slip-resistant properties.
The ability to recycle and reuse rubber floors is a major leap forward for designers and contractors. Now, many of the same properties that make SBR rubber a great commercial floor will benefit consumers, children, athletes and the environment, well into the future.
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