Advancements driven by trends

Adhesive and sealant manufacturers make improvements to meet building styles
Katy Devlin
October 27, 2009
COMMERCIAL : SALES, TECHNOLOGY

Current building trends—increased energy efficiency and sustainability, large expanses of transparent wall systems, more design freedom—affect the glass and glazing industry in obvious and not-so-obvious ways. Just as glass and framing companies are developing bigger, stronger and greener products, adhesive and sealant manufacturers also are following the trends and making improvements.

Current building trends—increased energy efficiency and sustainability, large expanses of transparent wall systems, more design freedom—affect the glass and glazing industry in obvious and not-so-obvious ways. Just as glass and framing companies are developing bigger, stronger and greener products, adhesive and sealant manufacturers also are following the trends and making improvements.

This article looks at how three adhesive and sealant companies are adapting their products to current building trends.

Energy efficiency and sustainability

Lower volatile organic content has been the most major shift for adhesive and sealant makers following the green movement. To meet requirements from the U.S. Green Building Council’s Leadership in Energy and Environmental Design program, manufacturers need to generate products with low VOCs.

“The green movement is directly affecting sealant chemistries. It is a big issue for adhesives,” says Mike Sebold, business leader, building envelope solutions, Tremco, Beachwood, Ohio. “There has to be a lot of reformulation with solvents to meet green standards.”

The push for better thermal performance has driven the popularity of foam spacers. In the insulating glass sealant market, demand for hot-melt sealants has increased, says Paul Chackery, product manager, Fenzi North America, Toronto. The price point is lower for hot melts, making them an attractive option for manufacturers investing in more costly IG units with higher thermal performance, he says.

However, IG manufacturers using energy-efficient low-emissivity glass will use a non-hot melt product, such as a polysulphide or a silicone, Chackery says. “Hot melts are thermal plastics—butyl rubber. You heat it up to 107 degrees Celsius, it melts, and you apply it. When it comes down to room temperature, it hardens up. It doesn’t really bond; it’s the tackiness of the hot melt that holds it together,” he says. “When the temperature is very cold or when the glass gets very hot, which can happen with low-E glass, the sealant becomes softer.”

Product life span also has become more important as sustainability demands grow. “We’ve been developing technology to double, if not triple, the life span of the products,” Sebold says. Silicone has become a more popular sealant component because of its durability and sustainability.

C.R. Laurence Co., Los Angeles, developed a hybrid polyurethane sealant that incorporates silicone into the chemistry. “[The hybrid sealant] lasts longer because of the silicone technology,” says Gary Byrum, CRL product manager.

Aesthetics

If an adhesive or sealant is visible on the completed project, its appearance needs to live up to the architect and owner’s aesthetic requirements. One major issue with traditional polyurethane products was that they tended to yellow, Byrum says.

“CRL brought [the hybrid sealant], an advanced silyl-terminated polyurethane technology, to the glazing and window markets to provide a non-yellowing white color polyurethane for exterior perimeter sealing of windows and doors,” he says. The hybrid technology that allows for sustainability also prevents yellowing. “More and more sealant manufacturers are coming out with similar products.”

Unitized curtain wall

The emergence of unitized curtain wall also put the spotlight on sealant manufacturers. “When we do unitized, silicone is the only thing holding glass on the wall,” Sebold says. Manufacturers and glaziers want “command cure” with unitized wall systems. “Manufacturers are pushing speed, but we can’t sacrifice adhesion,” he says. “As sealant manufacturers, we need to balance those factors.”

Tremco developed a product for plant unitized systems that cures in about four hours and can be structurally glazed in 24 hours.

Protective glazing

“The primary function of sealants used to be to keep air and water out. Now we’re challenged as they need to be designed for hurricane and blast,” Sebold says. Tremco began its research and development on hurricane products about 10 years ago, and on the bomb-blast market about three years ago. “[Prior to that], the federal government was the only one using bomb-blast specifications. But, we’re starting to see it with private owners, banks and local municipalities,” Sebold says.

Tremco also developed a product for seismic systems.

Katy Devlin is editor for Glass Magazine. E-mail Katy at kdevlin@glass.org.