Volume 50, Issue 3 - March 2015

Skinny Dipping

by Ellen Rogers

Bigger isn’t always better, but size always matters. And while architects may be eyeing massive-sized lites, which promise transparent spans of uninterrupted views, another little product—and we do mean little—is slowly, but quite surely, making its way onto the architectural scene.

The glass technology live pavilion at glasstec 2014 featured an innovative art glass structure constructed with AGC’s thin glass product.

Super-thin glass—glass that’s approximately 1 mm thick, even less in some cases—is nothing new. It’s been a staple in the consumer electronics industry for years; just take a look at your smartphone or tablet. For those applications, strength and scratch-resistant properties are probably the biggest benefits. Those characteristics are also important in architectural glass, and over the past few years manufacturers have started looking at the market’s potential. These companies include both AGC and Corning Glass, among some others (editor’s note: Schott is also working on a super-thin product, but declined to comment for this article).

The question, though, is where can it viably be used?

“It’s difficult to say, because there’s no market for it,” says Dirk Schulte, vice president, business development for contract glazing firm APG International Inc. in Glassboro, N.J. “You have to create the market and create awareness.”

However, there are a lot of questions and uncertainty surrounding its use in architecture. The possibilities exist, but in what applications and at what cost?
Super-thin glass, which can be less than a millimeter in thickness, is incredibly flexible and strong.

The Bare Essentials

If you want to better understand the unique characteristics of thin glass, start by considering what it is not. Consider what it’s missing. For one, there’s no iron and soda lime, resulting in a pristine, clear aesthetic. It’s typically not tempered so there are no quench marks. Instead, its strength is the result of a chemical strengthening process. According to a report presented by APG during GlassCon Global in July 2014, during this process, “the glass takes in charged particles (ions) which are effectively ‘stuffed’ into the glass surface to increase the surface compression … [which is] much higher than that of the conventional thermal tempering process …”

A retractable-foldable canopy constructed with Corning’s Gorilla Glass was on display during glasstec 2014. APG International handled the installation, while SFL of Austria was the glass laminator.

Strength is its key advantage. Speaking of her company’s Gorilla Glass product, Christie McCarthy, director, product management, Emerging Innovations Group with Corning Glass in Corning, N.Y., adds that its damage-resistance aspect ties into that as well.

“At about half the thickness, it can triple the load to failure when compared to strengthened soda lime glass,” she says. “If scratched, it takes a lot more damage to cause that scratch to become something that can break. In other words, it can handle those scratches without causing catastrophic failure.”

Robert Metter is the director, business development for AGC Electronics America. His company has two thin products—Leoflex, which is for the building and industrial communities and Dragontrail, for displays and touchscreen applications. Leoflex, he explains, is derived from Dragontrail. He says the Leoflex chemically-strengthened product is five to seven times stronger than conventional tempered glass.

“You can replace a 4- to 6-mm thick panel with a .075- to 1.1-mm thick Leoflex panel,” he says, speaking of this benefit. “Next, you get much better light transmission due to the reduced thickness and lower iron over conventional glazing materials. Additionally, the chemical-strengthening process nearly eliminates any hazing due to environmental interaction. For example, sea spray near the ocean will not cause appreciable haze.”

While strength may be a desirable feature, these products do come with a certain limitation. At a time when “the bigger the better” is becoming a mantra for many on the architectural side, the available maximum size of super-thin glass poses somewhat of a disadvantage. Sizes available come in the neighborhood of about 4 by 5 feet, plus or minus a few inches. Metter, though, says this could change with larger chemical-strengthening tanks.

Searching for Answers

The use of super-thin glass in architectural applications is very much in its infancy, and with that comes a lot of questions. The product is unique, and in many cases requires special considerations compared to conventional glass products. From cleaning and handling to further processing, here’s a closer look at some points to keep in mind.

When it comes to cleaning, experts say products and procedures used on float glass are fine. Handling, likewise, should be done in the same manner: with care. Take care around the edges of the glass and exercise caution when there’s metal-to-glass contact.

Robert Metter, director, business development with AGC Electronics America, adds, “Care is required to not damage the surface and chip the edges.”

Shipping and receiving may also call for added attention, given the flexibility of the glass. For example, two-person control may be essential when removing the product from crates.

McCarthy also points to another special consideration. Once the glass is strengthened, it cannot be re-cut in the field. This is because of the chemical process that gives the glass its strength.

Speaking of Gorilla Glass specifically, McCarthy says, “We use an optimized glass composition and our proprietary fusion process to produce thin, pristine glass. Then we cut it to size and put it through the ion exchange process where small sodium ions are replaced with larger potassium ions,” she explains. “As that happens, the glass is put under compression, which makes it stronger.”

As a result, once strengthened, it can’t be cut with typical tools on a construction site.

“Right now, due to our strengthening process, our glass cannot be re-sized in the field,” she says.
McCarthy says they haven’t seen many requests for slots or holes to date, but should a customer require them, the drilling would need to be done prior to strengthening.

While there may not be a “use by” date on these products, manufacturers agree that a long, healthy life in the field can be expected.

Metter says longevity should be “longer than conventional float glass due to better chemical resistance and superior weatherability,” as well as “far superior impact and scratch resistance.”

“What it looks like on Day 1 is what it looks like on Day 1, 000,” says McCarthy. “Because Gorilla Glass is scratch-resistant and durable, it can withstand everyday wear and tear and is easy to maintain, reducing the maintenance cost for the building owner.”

Small, But Mighty

What are the best applications for the glass, given its strength and size? Metter suggests a number of possibilities: transportation, security, marine, creative architecture (such as decorative) and elevator cabs.

McCarthy agrees and says her company has been involved in a number of similar applications.

“We sell Corning Gorilla Glass for interior architectural applications and currently have two system makers with whom we’re working, SnapCab and Elevecture [both manufacturers of elevator interiors systems],” she says. “We sell to them, and they sell the full system.”

She adds that on the canopy side they’ve done development work with SFL Technologies out of Austria and APG.

“SFL is laminating the Gorilla Glass for use in their engineered canopy design,” she explains of the concept display featured last fall at glasstec.
Because of the enhanced flexibility, super-thin glass has the potential for use in various cold-bending applications, such as skylights and other overhead glazing projects.

AGC also featured thin glass innovations at glasstec. Its Dragontrail X was used in the glass roofs for the players’ benches at the 2014 FIFA
World Cup in Brazil, which it displayed at the show. According to AGC, the glass is eight times stronger than typical soda-lime glass, even though it is very thin and light.

But strength is not the only consideration. Thin glass is also incredibly flexible. Depending on its use, that’s a quality that can be viewed as both a positive and a negative. Metter says, for example, the glass can be used for simple bends without a thermal forming process.

Schulte agrees, and says thin glass could be used in cold bending skylights, for example. He points out, though, that because of this flexibility, it isn’t necessarily something that could work in a conventional façade.

Other contract glaziers also have interest in these products and their potential use and development. Speaking of overhead applications, Jeff Haber, a partner with W&W Glass in Nanuet, N.Y., says, “Depending on their strength, ultra-thin glass panels instinctively would result in less weight, bulkiness, cost and sightlines for supporting framing systems as they would not need to support the heavy weight of thicker glasses, especially in overhead applications.”

It may seem easy to look at architecture and point out where the glass could be used, such as in canopies and elevator cabs. But what about taking thin glass and using it as an architectural component? That’s one possibility that Schulte thinks could be considered. He explains the European market is seeing greater use of triple-glazed insulating units, given the push to lower U-values; this is also making its way to the U.S. If the intermediate lite is replaced with a thin glass product, it could significantly reduce the added weight of a triple IGU compared to double glazing.

“The biggest mass application I see is its use as an integral member of triple-glazed insulating glass units,” he says. “We will see a lot of triple IGUs, where thin glass will be used as that intermediate glass layer in the future.”

McCarthy agrees there is potential for use on these applications, but the cost concern may still be an issue. She says they are open to these discussions, but there’s the question of whether it makes sense, particularly given the premium price.

Finding a Comfort Zone

Super-thin glass is one product that doesn’t come cheap. Metter says the thin glass can range anywhere from five to 10 times more than the cost of traditional float glass.

But before anyone buys it, they must first know about it, so simply generating awareness is a major hurdle. Schulte says groups, universities and others are using research efforts to find projects where it could be tried out. They would then create comparison charts to gain a real understanding of whether it makes sense to use.

“I think it will find its place in the market, though it is not a universal solution for each and every [application],” he says. “The industry will see marketable products and systems in the coming years where it will be implemented as an integral and cold bent member, but whether it’s sustainable or not is tough to say at the moment.”

He continues, “At the end of the day everyone thinks it’s great, but when it comes down to what we can do with it … they don’t know exactly. So let’s come up with a plan and create a list of applications [where it could work].”

Thinking Ahead

New products, technologies and ideas can be exciting. Yet, they require a certain amount of trial-and-error before they can fully reach marketability for the masses, or at least more architectural niches. Schulte points to the retractable-foldable thin glass canopy featured at glasstec 2014 as an example. The concept design was outstanding, and showed a first glimpse of how thin glass can be used, yet it is not something implemented in the field.

“It’s an intention to think ahead and how the technology can be further implemented.

“There are a lot of unknowns in terms of its behavior in real applications right now,” he says. “It’s a great product and has future potential in the sophisticated, architectural market. But it’s still in a very early stage, and needs consideration and further development.”

the author
Ellen Rogers is the editor of USGlass magazine. Follow her on Twitter @USGlass and like USGlass on Facebook to receive updates.

Copyright 2015 Key Communications Inc. All rights reserved.
No reproduction of any type without expressed written permission.