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Q: What does a wood products manufacturer need to consider when deciding between a traditional adhesive and a new "green" adhesive?
David Hemm, vice president, Performance Adhesives, Hexion Specialty Chemicals: The word "green" gets used a lot in the industry these days, but it means different things to different people. To me, an adhesive can be "green" in three ways. One, it can be made from sustainable raw materials. Two, it can be produced in an environmentally suitable manner. Or, three, it can be low VOC-emitting. While not mutually exclusive categories, these are quite different standards for judging whether an adhesive is green or not.
A wood products manufacturer trying to decide between a traditional and green adhesive should first ask: what am I trying to accomplish?
If your No. 1 objective is to qualify for LEED green building credits, the most important thing to remember is that your products cannot utilize urea formaldehyde adhesives. You'll need to look at alternate chemistries or bio-based alternatives such as casein glues.
If meeting the new California Air Resources Board (CARB) indoor air quality standards is foremost in your mind, ask both your composite panel and adhesive suppliers about their low emitting options. Both synthetic, formaldehyde based and bio-based products are currently available to help wood product manufacturers comply with these ceilings, which go into effect next year.
Brian D. Brady, marketing manager, 3M Industrial Adhesives and Tape Division: Demonstrating that low emissions and high-strength bonds can co-exist, the full line of 3M industrial adhesives with GREENGUARD certification are well suited to a wide variety of applications, such as flooring, countertop laminations, furniture and mattress manufacturing, as well as ceiling and wall systems. This certification states that the chemical and particle emissions from these adhesives are low enough to meet the levels of indoor air quality standards set by GEI, one of the five key areas of human and environmental health within the United States Green Building Council's LEED® program.
Tom Sennhenn, technical director, Specialty Polymer: It is very important that the wood products manufacturer stay current and in compliance with constantly changing environmental, health and safety regulations. The reduction or elimination of Volatile Organic Compounds (VOC), especially Hazardous Air Pollutants, (HAPS) has been an important goal of the EPA and industry in recent years. If the switch to a "green" wood adhesive is required in order to meet these goals, the most important considerations would be product performance and economics. As wood adhesives are transitioned to new "green chemistry," there could be compromises made in terms of how well the adhesive will perform. Most likely to be affected by these changes are adhesion, water resistance and heat resistance. Hopefully, the adhesive manufacturer has been able to match performance of the traditional product with a new green product, but in some cases this is not possible. The traditional chemistry has allowed high levels of performance that are hard to match. In some cases, in order to match the higher levels of performance, the new green alternatives might be made with more exotic, higher cost raw materials, which can drive up the price of the new green wood adhesive, and make its use impractical.
Q: What are the advantages of using a green adhesive? What are the disadvantages?
Hemm, Hexion Specialty Chemicals: The advantages of using a "green" adhesive range from the practical to the emotional.
Qualifying for LEED credits, meeting CARB ceilings, or adhering to other eco-conscious criteria such as those recently issued by the National Association of Home Builders may require the use of greener adhesives.
Wood products manufacturers may also be able to create a competitive advantage for their offerings through the use of green adhesives. Concerns about climate change, global warming and conservation are driving consumer interest in greener products. Meeting this psychological need to be eco-friendly can be good for business — and good for the world — at the same time.
The disadvantages depend upon the specific green adhesive and its properties. Costs associated with going a more natural route can be higher. There may also be some processing drawbacks with green adhesives including slower cure speeds and other handling issues.
Brady, 3M Industrial Adhesives and Tape Division: Advantages: Manufacturers and builders have another resource to help them pursue LEED® rated projects, which can lead to greater product demand for manufacturers and faster occupancy rates for builders. Manufacturers can market themselves as supplying low emitting products, allowing them to participate in this mega trend. Their use can lower the number of flammable materials to manage, and the water-based adhesives in this line can help alleviate fire safety concerns. The use of low-VOC adhesives that are GREENGUARD certified can help improve overall worker safety (eliminate transportation).
Disadvantages: Some green adhesives slow down production. However, 3M has products such as Fastbond 2000 a water-based contact adhesive, that when sprayed can form bonds immediately. Other products like ScotchWeld 94CA not only meet stringent GG standards, but also have a unique formulation and delivery system that allow for rapid bonding. Some green adhesives are costlier. However, when you look at total costs, including the cost of managing regulated materials, cost per square foot coverage and application speed, you will find that you are better off using time-tested, market-proven GG certified adhesives.
Sennhenn, Specialty Polymer: The most obvious advantages to using the new green technology are worker safety, consumer acceptance, marketing advantage, and compliance with federal, state and local environmental and safety regulations. These advantages would be realized by lower odor and lower toxins in the workplace, the marketplace, the landfills and water treatment plants.
Disadvantages would be the potential for loss of adhesive performance and potentially higher cost as raw materials are changed for more environmentally friendly options.
Q: In what situations, if any, should a traditional adhesive still be used over a greener one? Why?
Hemm, Hexion Specialty Chemicals: Adhesive technology has advanced to the point that both natural and synthetic products should deliver comparable performance characteristics, at least for millwork and joinery applications.
Currently, one area where traditional, petrochemically derived adhesives are probably preferable is structural applications such as I-joists, glue laminated beams or finger-jointed stud walls. Here, durability and performance are at a premium. The components of bio-based products are, by definition, prone to biodegrade — which is not appropriate for load-bearing ceilings, floors or walls. Improving technology in this area may make bio-based products suitable for these applications in the future.
Brady, 3M Industrial Adhesives and Tape Division: There may be situations that green adhesives don't always meet the customer's requirements. Some situations might include environmental resistance, processing requirements, unique substrates, economic considerations or cases where there is no driver for a green solution. In all cases, working closely with your adhesive manufacturer will help you select the correct adhesive for the job.
Sennhenn, Specialty Polymer: Product performance would dictate the use of a traditional wood adhesive over a green alternative. There are situations where the only product that will pass performance tests, such as Type I or Type II water resistance, is based on traditional wood adhesive chemistry. As more product development work is done, and more environmentally friendly options become available, this may change.
Comments? If you would like to weigh in on this issue, please send your comments to Kim Kaiser at kim.kaiser@wooddigest.com.
author: By Steve Ehle