Flexible Polyurethane Foam Applications
Carpet Cushion
Flexible polyurethane foam (FPF) is widely used as carpet cushion, or carpet pad. It is used to provide more comfort underfoot, reduce carpet wear from foot traffic, and provide a vareity of aesthetic benefits. More than 1.4 BILLION pounds of FPF are used annually for carpet cushion.
Interestingly, most of it comes from recycling.
Flexible polyurethane foam makes up approximately 85-90% of the carpet cushion market.
The right carpet cushion makes a flooring system with carpet look better, feel better, and last longer.
Carpet cushion fulfills several functions. Carpet cushion absorbs noise, so rooms are quieter. It also helps absorb the initial shock of foot traffic on carpet, which can cause carpet fibers to compact and lose height, creating “matting” effects. Carpet-even “no mat, no crush” styles-retain their looks longer if carpet cushion is used. Many carpets with appearance retention warranties require the selection of a proper carpet cushion to validate the warranty.
Carpets installed with proper cushion also tend to feel more comfortable underfoot. The layer of cushion makes vacuuming more efficient, because it allows the vacuum cleaner to “lift” the carpet. This creates better air flow, collecting dirt that would otherwise be trapped and cause carpet fiber to fray.
For commercial installations, carpet cushion improves carpet life, but also offers another benefit: Carpet over cushion is less costly to remove and replace than carpet that is glued directly to the floor. For all these reasons, carpet installed over cushion is more economical in the long run, providing extra value from the original investment in the floorcovering.
Benefits of FPF In Carpet Cushion Applications
Support
Flexible polyurethane foam carpet cushion supports the carpet above it, allowing it to flex under foot traffic but helping it maintain dimensional stability and tension from the original installation.
Comfort: Softness Underfoot
FPF carpet cushion absorbs pressure from foot traffic, making walking and standing more comfortable. This can also help reduce fatigue for people who stand for long periods of time.
Comfort: Insulation
FPF Carpet cushion can be added as an extra layer of insulating material to the flooring system, helping keep the floor warmer in the winter and preventing air conditioned coolness from escaping through the floor in warm months.
Value
Carpet cushion adds value to the flooring system. Good quality cushion is affordable, and can help add years to the life of the carpet. In fact, some carpet manufacturers base their warranties on carpet installed over properly specified carpet cushion. In commercial installations, carpet installed over cushion is much less costly to remove than carpet glued directly to the floor.
Comfort: Quietness
Foam carpet cushion absorbs force and reduced sound from foot traffic, helping keep interior environments quieter–a key benefit for those who work from home.
Durability
Technically, carpet seldom “wears” out. Instead, it “uglies” out, with fiber crushed and traffic patterns appearing. Flexible polyurethane foam carpet cushion helps prevent “uglying” out by absorbing force and providing an extra level of resilience. This can lengthen the life of the carpet by years. With high quality carpet cushion, carpet manufacturers may offer extra years of warranty protection.
Care: Hygienic
Polyurethane does not support the growth of bacteria or mold. This benefits flooring systems where spills and pet accidents may be commonplace. Carpet cushion also makes cleaning more efficient, since it allows air to circulate under the carpet, making vacuum extraction more effective.
Sales Appeal
It’s easy for manufacturers and retailers to demonstrate how flexible foam carpet cushion can benefit a flooring installation by adding comfort, support, and durability.
Versatility
Flexible polyurethane foam carpet cushion can add benefits to high traffic commercial carpet installations and light traffic residential installations.
Convenience: Lightweight
The light weight of foam makes carpet installations with cushion easier for installers. Foam carpet cushion can be shipped and warehoused easily as well.
Recyclability
FPF carpet cushion is one of the biggest success stories in recycling. Virtually all commercial foam scrap, along with thousands of pounds of post-consumer scrap (and continually increasing) are recycled into high quality bonded carpet cushion. Used cushion can also be recycled.
Bonded (or “rebond”) carpet cushion made from FPF makes up the majority of carpet cushion sold. It’s made by grinding up scrap foam into small particles, which are bonded together with adhesives and heat. This gives bonded cushion its distinctive multi-colored look.
Solid colored FPF carpet cushion can be made with several different processes. “Prime” carpet cushion is made with the same process as foam for furniture or bedding. A large foam bun is poured and sliced into thin sheets. “Frothed” foam carpet cushion is made using carpet backing machinery. Liquid ingredients are applied, either directly to the back of some carpet styles, or to a non-woven material (for making separate cushion). The materials react and form a thin dense foam, which is useful for commercial applications with wide expanses of carpet.
In addition, some companies are now using viscoelastic (“memory”) foam to manufacture carpet cushion. This is also a high density premium grade of cushion, which relies on the force absorption properties of viscoelastic foam to provide extra protection for the carpet. Viscoelastic foam may be combined with bonded foam to enhance performance characteristics.
Key Characteristics of FPF Carpet Cushion
Key
Flexible polyurethane foam for carpet cushion applications is specified based on several characteristics:
Traffic: The amount of foot traffic in an installation should be the first consideration for selecting a carpet cushion. Higher traffic areas (commercial installations, playrooms, rooms that have distinct traffic patterns) require cushion with higher density foam and a cushion profile that has less thickness. In lower traffic areas, such as bedrooms, it’s possible to use thicker cushion for a softer feel underfoot.
Density: Density is based on the weight of the foam in the cushion measured in pounds per cubic foot. Typically, higher density cushion provides better support for the carpet.
Thickness: A cushion that’s too thick can cause the carpet to flex too much under too much traffic, which can increase wear and may require the carpet to re-stretched.
As minimum requirements for carpet cushion, the floor covering and foam industries typically refer to a set of guidelines established by the U. S. Department of Housing and Urban Development (HUD) for FHA built or financed housing. This standard, HUD UM72a, covers all major carpet cushion types and is recognized by many sources as providing good minimum criteria for proper cushion selection.
The HUD specifications have been in place for many years. The Carpet Cushion Council recommends better grades of carpet cushion than the HUD minimums be used when possible, to provide more support and cushioning for carpet. Also, check with the manufacturer of your carpet to see if there are minimum cushion requirements needed to keep warranties in effect.
A Recycling Success Story
Most carpet cushion sold in the U.S. is made from recycled flexible polyurethane foam. According to the Carpet Cushion Council, approximately 600 to 700 million pounds of scrap foam are recycled each year from post-industrial sources.
Foam producers and fabricators, along with other foam users have become very efficient at recovering all scrap foam from their manufacturing processes. Virtually all post industrial foam scrap in the U.S. is recycled into bonded carpet cushion.
Post-consumer recycling is also increasing, using foam recovered from carpet cushion, home furnishings, and mattresses. The scale of this challenge is massive; there are literally millions of pieces of furniture and mattresses that go into landfills, and there are no standardized systems for breaking down home furnishings into individual compo nents. PFA, the mattress industry, the Carpet Cushion Council and other organizations are working together to continue development of these recycling channels.
According to an estimate by the Carpet Cushion Council, post-consumer take-up carpet cushion recovery diverts between 400 and 500 million pounds annually from land fills to the manufacture of bonded carpet cushion.
There are already programs for mattress recycling in several states, including California, Connecticut, and Rhode Island (as of 2019), which recycle more than one million mattresses each year. The mattress industry has created an organization, The Mattress Recycling Council (www.mattressrecyclingcouncil.org ) to research and develop more recycling opportunities and economic models for recycling bedding products.
Another element in the challenge is the presence of flame retardants (FRs) in many furniture pieces. FR use in furniture was effectively mandated by a 1978 California regulation (California Technical Bulletin 117), which was modified in 2013 (California Technical Bulletin 117-2013) to allow for the use of non-FR foam. Nevertheless, tens of millions of furniture pieces containing FR foam remain in use. By blending recycled foam containing FRs with other foam scrap, concentrations of FRs are significantly diminished, and the recycled foam can be used productively, rather than being discarded.
PFA, along with the Carpet Cushion Council, participated in a National Science Foundation (NSF)-sponsored work shop, “Management of Waste Foams and Plastics Mixed with Flame Retardants.” At NSF’s request, PFA worked with the Carpet Cushion Council on a peer-reviewed publication in a science journal documenting the benefits of mechanical recycling of FPF into carpet cushion and the accompanying “blend down” of FR content.
Quality Stewardship
Challenges
Green Label Plus (GLP) is an independent laboratory testing program that certifies carpet, adhesives, and cushion with very low emissions of Volatile Organic Compounds (VOCs). This helps assure proper indoor air quality. Using GLP-certified products may qualify you to earn credits for Leadership in Energy and Environmental Design (LEED) and other Green Building programs.
The Carpet Cushion Council is the administrator of The Carpet & Rug Institute (CRI) Green Label Plus program for cushion. Firms desiring to qualify products under the program must complete and execute a CRI Green Label Plus Participation Agreement provided by the Carpet Cushion Council and satisfy other pre-enrollment requirements.
Upon successful initial testing, a product label ID number (assigned by CRI) is issued to the applicant. The participant is permitted to use the CRI Green Label Plus program logo on the approved product category in conformity with the CRI GLP Brand Standards. The label can be used in product literature, on hang tags and sample backs, etc. Use of the label is not allowed until the product is certified by the program. Participants in the program are informed of the results of tests by means of a written report from the Carpet Cushion Council indicating whether the tested sample meets the program limits.
Following acceptance in the GLP program, the Carpet Cushion Council annually collects a sample of the approved product category for assessment of TVOCs and for each of the mandatory VOC’s. All samples are collected using the CRI sample collection protocol and are assessed by the program approved laboratory. Specific details related to the CRI Green Label Plus program requirements can be found on the CRI website. (Link to: www.carpet-rug.org/GLP)
Participation in the CRI Green Label Plus program for cushion is open to and includes both members of the Carpet Cushion Council and non-members.
Related Resources
Related
Video: How Foam Is Made
Learn more about flexible polyurethane foam is made and how it is used in furniture, bedding, automobiles, carpet cushion and other uses.
Carpet Cushion Council
The industry association for carpet cushion manufacturers.
Flexible Polyurethane Foam: A Primer
Technical: Foam Carpet Cushion
Foam carpet cushion manufacturing and key characteristics.
Technical: Foam Density
An explanation of foam density and its importance.
Technical: Foam Recycling
How carpet cushion became a recycling success story.