Polyurethane is a highly versatile material capable of solving many problems and is used in the construction, furniture, bedding, automotive, binder and many other industries. Because they are durable, lightweight and versatile, polyurethanes can help reduce waste and consume less energy. Energy efficiency and recycling continue to be an important issue facing both industry and the consumer.
Polyurethanes are found in all facets of building construction from product manufacturing to solving critical application needs on the job. They are used as insulation, adhesives, sealants and binders in a variety of construction products and in numerous other uses. The desire and need for more energy efficient buildings has encouraged the use of more polyurethane products.
Together with the rest of the plastics industry, the polyurethanes industry endorses the practice of conserving resources and minimizing the environmental and health impacts of plastics and plastic products. CPI supports the use of:
- Environmental and energy-efficiency criteria in product design and purchasing decisions, along with product safety, cost, performance and availability.
- Environmental performance and energy criteria in product evaluations through a “systems” approach, using recognized life cycle analysis tools that include the entire “use” phase.
- Sustainable product criteria that reflect consensus-based decision-making, best available science, transparency, and openness to ALL stakeholders.
Saving energy in buildings becomes more important every day. A significant percentage of our nation’s energy is used to heat, cool and operate our homes and buildings. Energy lost through walls, roofs and windows is the largest single waste of energy in most buildings. Energy loss in buildings means extra operating costs, loss of comfort, and reduced productivity. When it comes to energy efficiency in buildings, plastic-based products such as rigid polyurethane foam (PUR), spray polyurethane foam, and polyisocyanurate foam insulation (PIR or polyiso) are at the center of the discussion because they are some of the most efficient thermal insulating products for buildings. They work to reduce heating and cooling loss, improving the efficiency of the building envelope.
Insulation performance is typically measured by R-value, or thermal resistance. The higher the R-value, the better the material insulates against heat transfer. PUR and PIR foams have some of the highest R-values per inch of all commercially available insulation products. With typical R-values in the range of R 3.6 to R 7.2 per inch, polyurethane products allow for energy efficient designs featuring thin walls and low profile roofs. This allows the architect or engineer to maximize the usable space in a building while reducing operating costs.
Innovative material design and technology advancements have resulted in high quality polyurethane insulation products that reduce energy loss. In a one-year study by Franklin Associates, plastic building and construction materials saved 467.2 trillion Btu’s of energy over alternative construction materials. The energy saved by using plastic building and construction materials in one year is enough to meet the average annual energy needs of 4.6 million U.S. households. In fact, the U.S Environmental Protection Agency estimates that homeowners who air seal and insulate their homes can save up to 20 percent of heating and cooling costs. Energy efficiency impacts more than just operating costs. Highly efficient walls and roofs may allow heating and cooling equipment to be downsized by as much as 35 percent. This may translate into more floor space for the same total price.
Traditional fibrous insulation products must be supported or protected by surrounding materials because of their low density. These insulation materials may be soft or sensitive to moisture, which is not the case for polyurethane insulation products. Polyurethane foam is a thermosetting insulation, providing structural performance and fire resistance. Polyurethane products have a strong yet lightweight structure, are dimensionally stable, moisture resistant and durable. This combination of properties allows manufacturers to design polyurethane thermal insulating products for many diverse applications and allows it to be attached to a wide range of substrates. In addition, when combined with the proper materials, they can perform as external air barriers, helping prevent the infiltration of outside air and the escape of indoor air.
This high performance combination is unique, encompasses a wide range of manufacturing processes, and results in thermal insulation products with multiple functions. For example, spray polyurethane foam (SPF) insulation products can be spray applied to various substrates and others can be molded to special shapes in relatively large sizes. High-density SPF has a high mechanical strength that can add rigidity to lightweight walls or roof decks. As a roof covering, high-density SPF can increase the wind uplift resistance of existing roof coverings. PIR sheathing products can practically eliminate thermal shorts and allow homeowners to get excellent value from all the insulation in the wall, which can reduce heating and cooling costs. Structural Insulating Panels (SIPS) are pre-manufactured in a variety of sizes, allowing for quick on-site assembly into a building using a minimum number of workers.
Demand from businesses and consumers for recyclable products is high. Helping recycle materials that would otherwise become waste is one way many companies and individuals are choosing to reduce their environmental footprint.
Like other plastics, many polyurethane products can be recycled in various ways to remove them from the waste stream and to recapture the value inherent in the material. Most consumers are familiar with recycling plastic bottles and containers at curbside. Polyurethane recycling, on the other hand, usually happens elsewhere—on job sites, in industrial settings, during building demolition—and takes many forms, from relatively simple reuse to breaking down the material into its chemical constituents.
Here are a few examples of the different types of polyurethane recycling:
- Rebond—Nearly a billion pounds of reclaimed polyurethane scrap was used in 2010 to create rebond cushioning used as carpet underlay.
- Mattresses—800 pounds of polyurethane foam is recovered each day from one mattress recycling facility in Alameda County, CA.
- Recycled content raw materials—A manufacturer in Michigan provides raw materials for polyurethanes (polyols) with up to 70 percent recycled content that are used in the automotive industry.
Polyurethane Recycling Processes
Polyurethane is recycled in two primary ways: mechanical recycling, in which the material is reused in its polymer form, and chemical recycling that takes the material back to its various chemical constituents.
- Rebonded Flexible Foam—Rebonded flexible foam or “rebond” is made with pieces of chopped flexible polyurethane foam and a binder to create carpet underlay, sports mats, cushioning and similar products. Rebond has been used for decades and represents nearly 90 percent of the carpet underlay market in the United States.
- Regrind or Powdering—Sometimes called powdering, regrind recycling takes polyurethane industrial trim or post-consumer parts and grinds them in various ways to produce a fine powder. The resultant powder is mixed with virgin materials to create new polyurethane foam or reaction injection molded (RIM) parts.
- Adhesive Pressing/Particle Bonding—These two recycling processes use polyurethane from various applications, such as automobile parts, refrigerators and industrial trim, to create boards and moldings, often with very high recycled content. Used polyurethane parts are granulated and blended either with a powerful binder [Link to PU Applications page section on Binders] or polyurethane systems, then formed into boards or moldings under heat and pressure. The resulting products, analogous to particleboard made from wood waste, are used in sound proofing applications, furniture that is virtually impervious to water and flooring where elasticity is needed.
- Compression Molding—This recycling process grinds reaction injection molded (RIM) and reinforced RIM parts into fine particles and then applies high pressure and heat in a mold, creating products with up to 100 percent recycled content and material properties that can be superior to virgin materials.
- Glycolysis—This process combines mixed industrial and post-consumer polyurethanes with diols at high heat, causing a chemical reaction that creates new polyols, a raw material used to make polyurethanes. These polyols can retain the properties and functionality of the original polyols and can be used in myriad applications.
- Hydrolysis—This process creates a reaction between used polyurethanes and water, resulting in polyols and various intermediate chemicals. The polyols can be used as fuel and the intermediates as raw materials for polyurethane.
- Pyrolysis—This process breaks down polyurethanes under an oxygen free environment to create gas and oils.
- Hydrogenation—Similar to pyrolysis, hydrogenation creates gas and oil from used polyurethanes through a combination of heat and pressure and hydrogen.
Key Opportunities to Expand Polyurethane Recycling and Recovery
- What is it?—Pull back the carpeting in today’s modern homes and most likely rebond is providing the cushioning. Created from flexible polyurethane foam production scrap and post-consumer cushioning products, rebond is easy to identify. It is made up of various sizes and colors of chopped pieces of foam that are bound together in one slab.
- Progress—Annually, around 90 percent of the flooring underlay market is rebond. Today, the market for “virgin” flooring underlay made from polyurethane foam is actually quite small due to the improved value and increased sustainability of rebond.
- Opportunities—In addition to the residential market, rebond is making inroads in hotels, institutional, retail and even marine applications. The market for rebond continues to expand beyond carpet underlay: between five and ten percent in the United States and Canada today is used for acoustic insulation in automobiles, gym pads, prayer mats, pet beds and mattresses.
- What Is It?—The amount of polyurethane foam used to give mattresses their cushy comfort is estimated at 300 million pounds per year in the United States. While that may sound like a large number, Americans eat four times that amount in potato chips each year. Regardless, companies that make polyurethane foam have successfully helped launch endeavors to capture and recycle it.
There are two primary methods to remove the polyurethane foam from mattresses—deconstruction by hand and shredding (and combinations of the two). Deconstruction by hand is more common; workers basically filet the mattress and remove the foam and other materials. This can produce up to 90 percent recyclable materials, but it is more labor intensive than shredding, which mechanically separates the foam and other materials and relies on less physical labor, but can result in fewer recyclable materials.
- Progress—The Mattress Recycling Council lists more than 25 North American recycling sites, noting that most facilities accept mattresses from commercial interests (retailers, hotels, hospitals, etc.) and not directly from consumers.
At the recycling facilities, workers form the foam into bales that are shipped primarily to thirty facilities across the country that make “rebond,” the predominate underlay used for carpeting and other flooring. The collected polyurethane foam is chopped and shredded into small pieces and then mixed with a binder under heat and pressure to form logs or blocks that then are peeled, sliced or diced like other polyurethane foam products.
- Opportunities—Mattress and polyurethane foam makers, along with recyclers, continue to seek new technologies to make mattress recycling more cost effective, while hoping to capture more used foam from more mattresses. The industry is pursuing new shredding technologies designed to increase the scope of mattress recycling as well as the yield of reclaimed polyurethane foam.
- What is it?—This process combines mixed industrial and post-consumer polyurethanes with diols at high heat, causing a chemical reaction that creates new polyols, a raw material used to make polyurethanes. These polyols can retain the properties and functionality of the original polyols and be used in myriad applications.
- Progress—One company uses glycolysis and other processes to recycle flexible and rigid foams into a new aromatic polyether polyol. The company opened a manufacturing facility in Michigan that supplies polyols to the automotive and manufacturing industries. The company’s formulations include up to 70 percent recycled content.
- Opportunities—Now that the process to reformulate reclaimed polyurethanes to meet commercial specifications has been established, the prospects have increased for expanded use of glycolysis and other chemical recycling. Opportunity largely will be driven by demand for recycled content in consumer products such as automobiles, furniture, appliances, insulation and packaging.
- What is it?—Many communities across the United States capture the energy content of their garbage in waste-to-energy facilities, recovering enough energy to power homes in five states or the equivalent of 28.6 billion barrels of crude oil. Polyurethanes and other plastics help energy recovery technology work better. Because plastics have a higher energy value than most other components of municipal solid waste, they help to significantly increase the efficiency of the energy recovery process.
- Progress—As one example, an energy producing company conducted a trial that added polyurethane scrap and other alternative fuels to coal. The trial was part of a goal to identify fuels that reduce emissions, reduce costs and do not impair operations. The trial found that the facility could process more than 500 tons of scrap material per day, and the company estimates that for each ton of coal displaced by polyurethane scrap, there is a reduction of more than eight pounds of harmful sulfur dioxide emissions.
- Opportunities—CPI helps identify facilities that have polyurethane scrap materials that can be used as an engineered fuel. CPI also participates with the broader plastics industry to promote increased energy recovery from polyurethanes and other plastics in municipal solid waste.
For the Consumer
Consumers have a large impact on the success of recycling of any material. By actively collecting products for recycling—and by buying products that are recycled or made with recycled content—consumers help drive both supply and demand.
In some instances, consumers can make a direct choice to buy products made with recycled polyurethane. For example, when buying carpeting, consumers can specify rebond carpet underlay made with recycled polyurethane. A few other cushioning and packaging materials also use rebond, such as pet beds, prayer mats, gym pads, packaging, plush toys and so on—consumers can ask the manufacturer or look for a label to determine recycled content.
To encourage polyurethane recycling, consumers can seek out retailers and manufacturers that support recycling in one way or another. For example, consumers can ask mattress sellers about their involvement in collecting and recycling used mattresses. Many automobile makers use recycled content in parts such as seat cushions, carpet underlay and acoustic insulation—much of this information is available on their web sites or through the car dealers.
As new uses for recycled polyurethane arise, consumers can increase demand by simply looking or asking for products that contain recycled content.
Recycled Plastics and Polyurethane Database
Moore Recycling, a recycling consultancy based in California, manages a list of contacts and companies that recycle polyurethane and other plastics in the United States and Canada. Interested parties can search by company name, zip code or state to match buyers and sellers of flexible and rigid polyurethanes. There are many buyers and sellers on the database: www.plasticsmarkets.org.
Resources and Links
- Mattress Recycling Council
The MRC has prepared this list as a service to the public to identify businesses that are involved in mattress disposal and recycling.
- Carpet Cushion Council (CCC)
As the industry resource for answers to carpet cushion-related questions, CCC educates carpet retailers, manufacturers, distributors, and cushion manufacturers about the benefits of carpet cushion.
- European Diisocyanate & Polyol Producers Association (ISOPA)
ISOPA represents the manufacturers in Europe of aromatic diisocyanates and polyols, the main raw materials for polyurethanes.
- International Sleep Products Association (ISPA)
ISPA is dedicated to protecting and enhancing the growth, profitability and stature of the mattress industry.
- Polyurethane Foam Association (PFA)
PFA is the trade association of U.S. flexible polyurethane foam (FPF) manufacturers and their suppliers. PFA is focused on the education of foam users and allied industries, addressing technology, safety and the responsible environmental and health record of FPF.
- Plastics Markets Database
This site's purpose is to connect suppliers and buyers of all types of scrap plastic, from bales to post consumer resin. It is supported by the plastics industry and intended for use by the recycling industry in the United States and Canada.