Speed, safety, and flexibility issues are driving the adhesive and lubricant industries to develop an arsenal of new products for today's ever more demanding industrial applications. IEN brings you a sampling of some of these breakthroughs below. For more information on these technologies, visit IENonline.com.
Turning to Adhesives
"More and more, mechanical fasteners are being replaced with tapes and adhesives to create lighter weight products with a smoother finish," observes Ann McGuiggan, marketing communications development manager of the 3M Adhesives Division. "Already, we've seen 3M tapes and adhesives replace screws and rivets in appliance, woodworking, transportation, and electronic applications." Structural plastic adhesives are being used to hold bumpers and rearview mirrors to cars, while light cure adhesives are bonding handheld communication devices. Hot-melt adhesives are now used in shelving units that can support half a ton of materials.
"Loctite has developed hybrid adhesive technologies, which combine the strengths of two or more existing adhesive technologies to eliminate the weaknesses of either technology alone," Mike Shannahan, Loctite Corp's director of OEM marketing, tells IEN. In 1999 the firm introduced a "hybrid adhesive technology formulated to overcome many of the limitations associated with both light-curing and cyanoacrylate adhesive."
These products offer instant fixtures and tack-free surfaces "in less than five seconds, tack-free cure without the use of solvent-borne accelerators, surface insensitivity, and excellent adhesion to a wide variety of substrates." More hybrids are in the development pipeline, according to Shannahan.
UV curable resins have long been used as inks and coatings for floors, cans, and containers, notes Clai Bachmann, senior vice president of marketing communications at Dymax Corp. (The photo shows a Dymax Corp light-curing adhesive, used for gasket bonding.) Their use has "grown significantly as adhesives, coatings, and encapsulants for a variety of assemblies and associated applications," she adds. While earlier inks and coatings were "deposited and cured in very thin layers," Bachmann explains, "new assembly adhesives and coatings are available in thousands of formulations typically cured in depths between 2 mils and a quarter of an inch. Typical applications include bonding of clear glass and plastics to themselves and other materials."
Coating applications range from conformal coatings for printed circuit boards to decorative dome types, and encapsulants are often used for electronic, microelectronic, and electrical components. "Some of the latest uses of light-curing adhesives are as formed-in-place gaskets and as temporary manufacturing aids replacing clamps, fixtures, and jigs," says Bachmann.
Dealing with Regulators
The adhesives industry remains vigilant about environmental and safety concerns. "Increasing regulatory pressure on companies using solvent-based adhesives has resulted in a range of water-based products available to consumers," says McGuiggan. "Responding to our own customers' needs for safer and more environmentally responsible products, we introduced our 3M Fastbond product line to replace solvent-based adhesives."
Loctite's Shannahan notes that the company works "proactively to meet the needs of customers and the requirements of new safety and regulatory standards," focusing in particular on solvent-free, low-VOC/ODC adhesive formulations; safer, low-odor and nonflammable materials; and "light cure technology (100% solids) as alternatives to two-component solvent-based systems."
Shannahan adds that the industry is "seeking to improve packaging, seeking alternative containers that will minimize the disposable packaging materials sent to landfills every year." In fact, Loctite recently introduced new 300 mL and one liter Press Pak packaging, a "plastic film container similar to sausage or cookie dough packaging that contains anaerobic flange sealants."
Dymax's Bachmann agrees that safety and regulatory issues are "steadily driving companies to look at ways to make their products more worker and environmentally friendly." Dymax has been designing adhesives with raw materials that "reduce regulatory compliance cost and provide 'safe use' advantages for our customers," Bachmann adds.
Adhesives in Space
Adhesive technology is not just earthbound, either. Eyesaver International is laminating 16 to 18 windows in the International Space Station's laboratory module and cupola using 3M's Optically Clear Laminating Adhesive 8141.
During Eyesaver's production process, the adhesive is applied to a nonhardcoated clear film adhered to the innermost window, referred to as the "scratch pane." The scratch pane is used to protect the outer window and the film is attached to prevent glass from shattering inside the station. The cupola's seven windows will allow the space station to view robotics operations, spacewalks, and experiments. Each of the windows should be ready for installation this fall. (3M's Adhesive 8141 will give astronauts a clear view; image, above, is from NASA's online gallery at www.spaceflight.nasa.gov.)
The adhesive's "uniformity is excellent; there is zero distortion, no coating voids; and the flatness has been unmatched," according to Eyesaver co-owner Steve George. "It has the optical clarity required by Boeing for photographing through the windows," explains partner Matthew Smillie.
3M manufactures this space-bound adhesive under clean room conditions, and the product is free of common adhesive defects such as bubbles and dirt.
The Future
Shannahan believes that the industry's "key concerns will remain a reduction in VOCs and ODCs, as well as making products safer by eliminating toxicity problems," over the next five to 10 years. "In addition, we see end users calling for faster cure speeds, and are focusing our efforts on delivering this capability in the near future."
More flexibility is also in store for users. "There is a surge in the number of manufacturers using low surface energy (LSE) plastics, yet there are few adhesive products on the market that are able to bond these materials," according to 3M's McGuiggan. "In addition to LSE plastics, there will be a growing use of powder-coated finishes and new display technologies that require optically clear solutions."
Electronics manufacturers are demanding "lighter, smaller, thinner, faster" adhesive products, McGuiggan notes.
Jerry Perkins, vice president of industrial marketing at Loctite, sees an "enormous focus on improving packaging technology. Loctite is always looking for better engineering adhesives/sealants. Right now, we're developing products that reduce the amount of packaging waste by 80%."
The future could bring growing reliance on fast curing products. These adhesives, which are quickly cured by exposure to light or during contact with activated surfaces, are replacing some slower curing urethanes, silicones, and epoxies, Bachmann observes, although these new resins "will likely never completely replace these technologies."
Safer Blends
Lubricant manufacturers continue to enhance established technologies. Rhoads Zimmerman, Kano Laboratories vice president of marketing and advertising, says his company is always looking to incorporate new additives to older, existing products. "We're also seeking new ways to mix, blend, or emulsify," he notes.
For example, Kano's formula for Silikroil aerosol, pictured at left, merges silicon and seven solvents, reducing surface tension while increasing lubricity and water displacement properties. The environmentally friendly product is free of HCFCs, trichlorethane, methylyne chloride, Freon, and all Class 1/Class 2 ozone-depleting compounds.
Within the next three years, Kano plans to blend other additives into existing products, following the track of Silikroil.
Cutting Downtime
Lubricating methods are getting smarter. The use of self-contained automatic lubricators has increased significantly, notes Donald C. Groetzinger, consultant to PLI.
Current technology allows engineers and technicians to install lubricators in more accessible locations on the plant floor, and reduces waste at the same time. For example, the Swiss-made Memolub HPS, shown below, which is marketed in the U.S. by PLI, is a reusable electromechanical device with a patented positive displacement pump operating under microprocessor control. This lubricator features replaceable lubricant cartridges and battery packs.
"The output operating pressure of the Memolub has been increased from the typical 50 to 75 psi, to 350 psi," Groetzinger explains, allowing operators to lubricate bearings 40 feet away from the device. This eases change-out, "avoiding the need for manlifts or ladders and, on occasion, equipment shutdowns." The lubricator also uses a distribution block to equally meter the lubricant to as many as 12 lubrication points. Armed with a selection of over 50 output rates, users "can accurately set the rate of ejection to the need of the application, thus avoiding over lubrication," notes Groetzinger.
Stamper Tries Smart System
High-speed stamper ETCO experimented with a variety of lubrication systems over the years. "For us, the results with rollers were hit or miss," recalls Dennis Herdegen, ETCO's vice president of manufacturing. ETCO tested spray systems, but abandoned the technology because of environmental concerns. "We didn't want our operators breathing in fog or mist in the press room," Herdegen states.
The firm then tried EFD's MicroCoat lubrication system, shown at left, on one of its Bruderer presses. The heart of the pneumatically operated system is the MC785 precision spray valve. Only 2.5 inches high, the valve uses low-volume/low-pressure air to apply lubricant in fine, even films without waste, mist, or overspray. Each system supports up to four valves, run by the MC4000 controller. Individual flow controls allow each valve's coverage to be adjusted independently.
"Now that we can control the amount of oil," says ETCO maintenance manager Rolland Blom, "we start out with each valve's flow control set at '1' [of 10] and fine tune the coverage to exactly where we want it, without stopping the press."
The cleanliness of ETCO's press room is also worth noting: a recent air quality test showed the oil mist load to be lower than 0.01 mg/m3, which is less than 0.2% of OSHA's current permissible exposure limit of 5 mg/m3 and less than 2% of the more stringent 0.5 mg/m3 standard that is under consideration.
