By Gerry Rector, Associate Marketing Director, Neenah Paper, Inc.
Familiar materials are being put to new uses to make wood products CARB compliant.
As companies scramble to comply with the California Air Resources Board’s (CARB) Air Toxic Control Measure (ATCM), it is driving the need for new technologies to replace urea formaldehyde. To date, companies have found precious few viable, cost-efficient alternatives.
Some are exploring the use of non-emitting natural materials such as soy, wheat straw and sunflower hulls. Researchers are also looking to existing synthetic resins to help fill the void.
Producers of veneer-faced furniture and panels who are concerned about how they will comply with California’s formaldehyde emissions restrictions can now breathe a sigh of relief. One of the first premium veneer and furniture backers made using No Added Formaldehyde chemistry was recently introduced. GreenGuard certification of the backer for low-emitting products was completed in November 2007.
Although backers, per se, will not be subject to California’s proposed regulations to reduce formaldehyde emissions, this product was developed to help veneer, plywood and OSB producers, and cabinet makers meet the most stringent Phase II requirements of this rule when used with their board products. As such, the backer must not add to the formaldehyde emission problem. Instead, it helps to solve the problem by eliminating formaldehyde-containing materials during the manufacturing process.
We will focus on only two resins for the purposes of this article—the well known acrylic and the less often used styrenebutadiene—and answer some common questions that are likely to arise about these materials:
• Are there many companies manufacturing no added formaldehyde products for the furniture/furniture backing industries?
Although no added formaldehyde products are still fairly uncommon, several companies are at various stages of developing and introducing them. Until now, the challenge has been to find alternatives to formaldehyde that can match it in cost-efficiency and durability.
• I’m familiar with acrylic, but I’ve never heard of styrenebutadiene. What sort of material is it? What advantages do products made with acrylic or styrenebutadiene have over those made with other formaldehyde alternatives?
Styrenebutadiene was one of the first synthetic materials to replace natural rubber and was used to make tires during World War II. Over the years, researchers have found a way to compound it for greater durability using no added formaldehyde crosslinkers. It has many applications and is widely used as an additive in everything from latex gloves to concrete.
Acrylic’s high strength makes it a much-loved component in items ranging from beauty products to clothing. You might know this man-made resin under the trade names Polycast, Plexiglass or Lucite. It has also gained a following among many customers of saturated backers.
Backers containing styrenebutadiene or acrylic don’t require the type of adhesives that react with moisture to create formaldehyde. The backer acts as a barrier between the adhesives, the veneer and surface treatments on the veneer, so the glue can’t bleed through. Another advantage is that the adhesives stay thermoplastic indefinitely, allowing furniture producers to repair unbonded areas with reheating if needed.
• What types of testing, if any, must No Added Formaldehyde products undergo?
There’s an industry standard durability test, called the Three-Cycle Soak Test, for which guidelines were developed by the American National Standards Institute and the Hardwood Plywood Veneer Association. The test calls for soaking the laminate for four hours, drying it for 19 hours and repeating this process three times. The goal is to make sure there is no delamination of the product. Only products that pass this test and meet all requirements for moisture resistance offer viable alternatives to their formaldehyde containing counterparts.
• Can No Added Formaldehyde backers containing styrenebutadiene or acrylic be used in high-end products?
Yes, they can most definitely be used in high-end products. In fact, they are more appropriate for high-end furniture rather than lower-end furniture and can be used with exotic species of woods.
• Is there anything else makers of veneer-faced furniture and panels should look for when specifying a backer product?
The backer should be an all-around performer and offer strength and toughness, smoothness, compatibility with a variety of substrates, and flexibility or stiffness, depending on which attribute is required.
In addition to the strength and dimensional stability provided by the saturant, the supplier should be versatile. For example, are the products also available with dry adhesive pre-applied on one or two sides? A dry adhesive glue line can eliminate the mess and inconvenience associated with wet glues. Some companies also specialize in creating and producing customized products for specific equipment or to meet process parameters.
When it comes to managing CARB(s), what’s old is new again. Although soy, wheat straw and sunflower hulls may perform well as low-emitting formaldehyde alternatives, they are cost-prohibitive in furniture/furniture backing applications. Styrenebutadiene and acrylic, newly repurposed, provide furniture producers with a wide range of performance attributes. For this reason, these synthetic materials—acrylic and styrenebutadine resins—offer wood products producers the best of both worlds.
Alpharetta, GA-based Neenah Paper Inc. (www.neenah.com) manufactures and distributes a wide range of premium and specialty paper grades, as well as producing and selling bleached pulp.
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