Wood & Wood Products talks with manufacturers of adhesives and adhesive dispensing equipment about emerging trends, including those seen at the recent AWFS Vegas Fair. For a complete listing of adhesive materials and equipment manufacturers, visit www.redbookonline.com.
The proper open time for adhesives depends on a variety of factors, including the season and the species and substrate of wood being used. There is no âone size fits allâ answer, and we recommend a call to technical support when a question arises.
A common cause of delamination may be attributed to the surface preparation of the components to be adhered. Wood and wood composite substrates are often sanded to achieve a uniform surface, and neglecting to clear the surface of the sanded wood dust residue often results in a superficial bond. The mated substrate, such as a high-pressure laminate, may delaminate with little depth of wood tear from the substrate, only some surface debris upon pull. Bond strength is greatly distorted by the inability of the adhesive to wet out or penetrate into the wood substrate.
It is important to always be aware of the surface condition of stock to be adhered, meaning an air applied cleaning, or using a brushing system to prepare the surface just prior to adhesive application.
There are many variables to consider when choosing an adhesive or method: production speeds, types of materials, environmental factors, processing temperature, end use of the product, cost effectiveness, priming, machine type, etc.
Adhesive materials and equipment companies must do more than simply produce an efficient product these days. Their job includes educating customers about todayâs environmental issues and how they can best be addressed.
âWe are seeing a lot of customers ask about green [issues] and LEED, and we are finding there is a big lack of information at the end-user level,â says Dave Hemm, vice president of performance adhesives for Hexion Specialty Chemicals.
âIn addition to answers to emissions questions related to LEEDs and the recent CARB proposals, customers are always looking for higher levels of service and technical support,â he continues.
âWe have people working with the Greenguard Council, so we can understand the issues for inside air emissions,â Hemm adds. âItâs all over the country...and it is trickling down so now we are seeing smaller and medium-sized shops interested in it, whereas before it was the larger shops.â
Scott Maxwell, AGM, says he also has seen an increase in the number of woodworking manufacturers requiring environmentally friendly adhesives. âIKEA, for example, is very particular about its environmental efforts,â he says.
And it is not just the furniture industry going green, notes Kent Pitcher, president and owner of CP Adhesives. âCustomers are looking for formaldehyde-free adhesive options in the manufacture of custom architectural panels, in light of the CARB initiatives, to severely reduce formaldehyde emissions in glued wood products.
âThey also want adhesives that will bond a wide range of materials, with short clamp times, and little or no mixing,â Pitcher adds. âIn addition, customers are interested in new and unique delivery and dispensing systems for their adhesives. They want complete adhesive systems that will increase efficiency and productivity in their operations.â
According to Craig Waters, business manager/high-pressure laminate adhesives for ITW TACC, the environmental efforts have impacted businesses in other ways, including insurance and worker safety issues.
âWe are seeing more and more business owners get involved with the decision making on adhesives. The business owner is saying, âI donât want the fire marshal in here. I donât want my insurance carrier to come in here and say hey you know what, you canât spray this stuff anymore.â They say, âI donât want to deal with that anymore â what have you got?ââ
No matter what, cautions Dave Herington, 3M marketing manager for spray adhesives, âYou still have to be price competitive. Customers also are looking for high performance and quality, as well as environmental compliance. Weâre seeing this even outside of California, in the Southeast and Northeast as well.â
Remaining Cost Competitive
However, says John Elder, northeast sales manager for Jowat, while customers are looking for time savings and environmental benefits, he notes that âThey are also willing to spend a little more to have a high-end product.â
Dennis Dodge, senior applications engineer for Nordson, concurs with Elder. âThere are people who are willing to spend more for quality, reliability and long-term cost reduction.â
âCustomers were interested in improving manufacturing processes and product quality, without increasing production costs,â adds Dodge. âSpecifically where adhesives are concerned, that means achieving full, thorough coverage without adding worker time and without over-applying â wasting â adhesive.â
âWhat gets us in the door is saving money,â says Jim Turner, vice president of Business Development for DUX Area, a manufacturer of adhesive spray guns. He says that the biggest customer concerns tend to be savings, safety and performance. âThe elimination of overspray makes for a much cleaner and safer work environment.â
Tim Brown, marketing manager for Henkel says that adhesive users are looking for products that enable increased throughput, without increasing per unit costs. âSuch products must achieve a variety of process requirements in a shorter time period, while also being user friendly and safe. Beyond processing, similar attributes must be inherent per the end user specifications, which may vary greatly,â he says.
Jerry Villa, vice president sales for American Adhesives Coating Corp., says he has been noticing requests for higher heat resistance, from 15F to 35F, in heat seal hot melt formulations for wood-to-wood and wood-to-paper applications. âCustomers also are asking for increased adhesive yield and a decrease in cost, without losing the current benefits in the formulations they now use.â
Along with increased yield, Adwood President Rudolf Stockinger says, âCustomers are looking for new products with longer pot life that can keep the glue in the pot longer without having to change it. Customers also are looking for fast and easy changeovers. If possible, they are looking to do this from the outside of the machine, with only a touchscreen.
|Among the new products for adhesives are portable, self-pressurized cylinders which can maximize material usage, with no waste in setup or cleanup.
Photo courtesy of 3M
New Technology Available
According to Pitcher, the new adhesive technology appearing in the AWFS show was in the area of polyurethanes, modified PVAs for no press gluing and soy-based formaldehyde-free adhesives. âThe polyurethanes received a lot of attention as both liquids and hot melts, because they offer such a range of benefits, including high moisture resistance, structural strength, and the ability to bond a wide range of dissimilar materials.
âThe formaldehyde-free, soy-based adhesive is really only in use by one hardwood plywood manufacturer and is yet unavailable to other users. It may offer an alternative to urea resin and PVA in custom panel manufacture,â he says. âA modified PVA for the no press panel system was in the new product competition and offers a simple cost-effective way to produce flat panels with either backed veneer or HPL faces, without the use of a press.â
In terms of dispensing equipment, Pitcher notes that pressurized containers for water-based products and liquid polyurethanes, and polyurethane hot melt retrofit units for edgebanders were featured. Pressurized containers, he says, offer several advantages, including the ability to deliver adhesive in controlled amounts to the correct surface for maximum bond strength. âThis reduces adhesive consumption, improves bonds and reduces cleanup,â Pitcher adds.
Portability is another plus for adhesive cylinders. âA lot of [companies] are having success with cylinders,â adds Herington. âThey also offer ease of maintenance, ease of use, high productivity and can be used with existing spray guns.â
Another new technology presented by 3M was a disposable nozzle system for spray applicators, which eliminates clogging. âThis was in response to customer demand,â says Scott Buss, 3M product manager for Scotch Weld Adhesives.
Also in response to customer demand is the slot nozzle. According to Elder, a slot nozzle enables users to apply a more precise amount of hot melt adhesive, while reducing the chance of contamination which can occur with an open roller system. âBecause of the precise control of the adhesive amount and temperature, customers are able to reduce the amount of adhesive applied, which can produce significant savings,â he says.
Other new products featured at AWFS include: low-emitting resins and adhesives, including solvent-free contact adhesives; fluorescent wood glues for uniform staining; water-based neoprene contact adhesives for laminating rigid substrates; no-mix adhesives for laminating; no-foaming urethanes; PUR adhesives featuring wide open times with low fixture times; and a foaming dispenser system.
In addition to a focus on improved environmental benefits, âAll new products are following a theme,â says Buss. âThey are all designed for performance and convenience.â
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