At the Glass Association of North America’s (GANA) Fall Conference last week, Jon Kimberlain of Dow Corning, BEC division chair, referenced the ESPN “30 for 30” series, in which they take an in-depth look at the background of sporting events. The tag line for these documentaries is “what if.”
In that spirit, “What if you knew how much GANA does to support our industry every day, would that change your perspective on the organization?” I’ve been a big fan of GANA’s for a long time. Last week only reinforced that. Again.
It’s going to take several blogs to deal with the high points covered. I’m looking at my notes (nine pages over roughly two days), and some of this is going to take several weeks just to cover one division. So here goes with Part 1, dealing with the laminating division.
Prior to taking the tour through the Intertek laboratory, Valerie Block with Kuraray Interlayer Solutions gave an update on the tornado-related code changes that are in the offing. They’re much the same as what we’re used to in the hurricane arena: small-, large-missile testing, but with two notable exceptions: the loads are greater, and there’s no need for cycling.
Wind loads in a tornado are 14 times greater than they are in a Level D hurricane design, so while the hurricane large missile test (ASTM E1886) calls for a nine-pound, 2-by-4 shot out a cannon at 35 miles-per-hour, tornado testing calls for a 15-pound 2-by-4 at 100 miles-per-hour. Essential buildings (e.g., schools, hospitals, tornado shelters, police and fire stations) are the intended targets for cladding upgrades, not just glass, but also brick, stone, precast, etc. The cycling durations we are used to in the window/hurricane testing are eliminated, as tornado events are too short to justify cycling. But, the glass must remain in the opening and not allow penetration of the missile through the glass. More to come on this front as the codes take shape.
The laminated glass, interlayer manufacturers and fabricators are working on several fronts in response to inquiries from the architects for laminated glass that can:
- respond to energy and sound;
- be available in larger lites with minimal support;
- offer ultra-clear glass in lami constructions;
- enable cold, warm, and hot bending; and
- protect birds.
Further, the industry is looking at how thick laminated glass can be, if there’s differences between annealed, heat-strengthened or tempered laminated glass, and incorporating the above functionality into a single glass lite. I discussed multi-purpose glass in a previous post.
ASTM E1300 relating to the strength of glass for wind load is a little weak when it comes to both minimally supported (think spider or patch fittings) and thick constructions. A standard for glass walkways is also being developed, since many of these incorporate laminated glass.
Edge quality is an issue. We talked previously about how to get laminated glass edges aligned, and it’s not clear if there’s going to be a standard about this, or if the individual lami fabricators are going to have to address it. There was some discussion about post-lamination glass edge fabrication, but interlayer folks are looking into what the fluids used for creating the edging on the glass will do to the interlayer. Long term exposure to these fluids (such as alcohol, water, etc.) is one concern that was expressed. Obviously, any heat treating of the glass prior to lamination eliminates the ability to do post-lamination edging, so that leaves post-lami edging to annealed, but annealed may not be acceptable for guardrail or handrail applications. This issue has to settle down, too; for now it’s not clear where the movement in the marketplace will take this.
On something of a more serious note: Codes and standards can only address “current knowledge.” As we saw last year at BEC in James O’Callahan’s presentation, there are folks pushing the envelope on what glass can do. We get asked the same sort of thing of our framing products at TGP, I’m sure everyone does, such as, “how big of a lite of glass can you support?”
Any and all of the standards groups—GANA, AAMA, ASTM, etc.—have a tough time staying ahead of the curve. The architects and designers keep asking more and more of all the materials associated with glazing, not just glass. Smaller frame members, less edge or smaller point supports of glass, can we up the design strength of structural sealants, etc.
So while GANA is accomplishing a lot to support the glass industry, please make sure the manufacturers who call on your company know where you see the market going, and what new and different things you’re being asked to do. BEC is the only part of GANA with direct ties to the glazing subcontractors who in the end put all of our industry’s products (glass, framing, sealants, gaskets) into service on every project.
We have to know where we can help you. It may require a more active role in helping us head in the right direction. So, with a final nod to ESPN, “What if you were to ask not what GANA can do for you, but what can you do to support GANA’s efforts to develop these codes and standards?”