New Technology, Equipment and Trends in Bent Glass -- Only Online USGlass

Only Online - USGlass September 2006

The Latest Angle
New Technology, Equipment and Trends in Bent Glass
by Alan B. Goldberg

Ask fabricators "what's new in bent glass technology?" and they'll likely say that nothing has changed much in the last ten to 15 years.

"It was an industry with tremendous growth, but I haven't seen anything lately that I would call earth-shattering," says Steve Sussman, vice president of J. Sussman Inc. in Jamaica, N.Y.

According to Steve Lerner, president and founder of Bent Glass Design in Hatboro, Pa., his company has been bending specialty glass with the same general concepts, despite recent innovations, that were used 50-60 years ago.

"The perception that nothing is new has to do with the way glass is now heated and the awareness of the latest developments," says Jeff Nichols, sales and marketing director for Standard Bent Glass in Butler, Pa. "New technologies may not be widely known," he says. Nicholas says that while his company continues to rely on its tried-and-true company-built kilns, it has also added new techniques and automated equipment.

Another issue for bent glass manufacturers concerns volume and production costs.

According to Lerner, even with high entry costs, high volume applications are going to India, China and other emerging economies where, with government subsidies and low labor costs, foreign manufacturers can better afford to invest in mass production and reap the benefits of economies of scale production that allow them to undercut the prices of American glass manufacturers. He says American manufacturers will never invest the necessary capital to attain high volume production in undifferentiated products because lower operating costs abroad make any domestic investment unprofitable.

"Unfortunately, it is undifferentiated glass that makes up the lions' share of global glass production," says Lerner.
Russ Alder, vice president of Precision Glass Bending in Greenwood, Ark., agrees.

"Machine manufacturers seem to be targeting markets where there is a demand for high volume runs of bent glass, such as in East Asia. This country is not the place [for bent glass]" he says. "The significant change is with machinery for flat tempering."

Lian Sawires, vice president of Gyrotron Technology in Bensalem, Pa., says one reason bent glass has not seen a great deal of growth in the United States is that it would require change.

"Change can be a hard sell. It requires risk and, because of the nature of this business and its dependence on the consumer market where quality and repeatability are critical to survival, change is difficult to make."

New Technologies and Developments
Robert Vandal, director of advanced product development, with Guardian Industries in Carlton, Mich., says that his company has been working with Gyrotron Technology on a pilot system for curved glass during the past two years.

He says with this new technology, the company can expect to accomplish two key things: rapid heating with fewer tools at lower costs; and a significant reduction in energy consumption.

"As one of the largest users of natural gas in the state, Guardian will benefit from the savings," says Vandal. "We're now brainstorming about the next phase, which is production."

Jim Schnabel Jr., vice president of product development for Glasstech in Perrysburg, Ohio, says the new developments are more evolutionary than revolutionary.

He says a heightened awareness of optical quality is part of the changes that are taking place. The trends are in tighter dimensional tolerances, improved optical quality and, like any manufacturing operation, an emphasis on reduced cost.

"We have spent most of our effort developing the capability to make the most complex shapes, with better operating economies in manufacturing and better recycling time," adds Schnabel. He says his company's architectural bending and tempering system requires no tooling and can increase cycle times.

Nichols says he sees developments in bent tempered/laminated glass as the next phase, describing a product that features two lites of bent, tempered glass bonded together with a polyvinylbutyral interlayer.

While such a product would make use of curved glass in the same applications as flat architectural glass possible, Nichols says at this point the process and technology is not readily available. He adds, though, that improvements in bending tolerances will create opportunities for production in a wide range of sizes to meet the full scope of the industry's demands.

New ovens are also being developed that offer numerous features.

The latest bending furnace from Glassrobots in Pirkkala, Finland, for example, is the only jumbo-size, serial-made unit on the market, according to Anders Holmqvist, sales director, who says the new furnace can bend glass lites as large as 10 feet by 19 feet.

Gyrotron is planning to introduce a new autoclave-free laminating system in the near future, according to Sawires. She says the system generates a fully heat-laminated glass in under 60 seconds, without an autoclave. Designed for large sizes, hurricane and other multilayer laminates, the system can be retrofitted into existing lines, replacing furnaces and pinch rollers. She says the company has also developed technologies for bending coated and non-coated glass, offering customers the ability to produce deep bends and repeatable complex geometries; zone heating to increase speed of conventional processing; and selective heating of decorative inks and coatings, without roller marks or bleeding.

Dick Joyce, vice president of Dlubak Corp., Blairsville, Pa., says his company has designed equipment to reduce some of the manual steps, such as cleaning and laying up of the interlayer, in the bent glass process.

"We are trying to offset the inflationary price spirals now common in the glass industry," he says.

The demand that is driving the creation of these new developments in is also significant.

"Glass architecture is in a state of transition," says Mauri Saksala, product manager for Tamglass Ltd. Oy in Tampere, Finland. He points out that architects are creating new concepts by combining flat surfaces and shapes. "New bending and tempering technologies without molds have taken the use of curved shapes to a totally new level; especially bearing in mind that the production costs are approaching the level similar to flat tempering," says Saksala.

He says that bent shapes, as well as the right combination of flat and curved sheets in different sizes, give architects the means to be unique. "The most important issue for architects is knowing that there are few limits for designing glass buildings, either flat or bent, in sizes and thicknesses."

At one time the only way to create a curved wall was to install flat glass sheets in a segmented curve, which formed a bent or curved glass façade that had corners and frames, explains Saksala, who says molds were then used to bend tempered glass. "While still useful, new technologies make it possible to bend and temper large glass lites, but without frames, creating very attractive curved glass. These new shapes can be made for low-E, laminated and insulating glass units.

Tamglass's new concept for bending and tempering large glass lites without the use of tooling or molds involves combining bending and quenching conveyor for sizes of about 8 feet by 14 feet, a minimum bending radius of about 5 feet and a maximum bending angle of a quarter of a circle. With this technology, Saksala says, it is possible to design attractive curved glass for facades, and shapes in sizes and thicknesses that can be processed at high production speeds with minimal changeover time.

Trends
Looking at some of the latest trends, bent glass can be found in both interior and exterior applications. Interior uses range from railing panels to shower enclosures to furniture. It can also be used to create dramatic lighting such as wall sconces, glass columns and other fixtures. Revolving doors also make use of curved glass, forming a transparent barrier around rotating doors. Curtainwalls, domes, solariums and windows are some outdoor applications.

Going back inside, the bathroom is one area where Oben USA sees a bright future for curved glass.

"We're turning a standard shower into a home spa. The traditional bathroom is becoming a shower haven," says Derek Englefield, president. The company has introduced a curved, frameless glass shower that is designed to be installed quickly and easily. "The affordability of the shower is due to the simple way it can be customized to virtually any space," says Englefield.

Referring to the potential for curved, frameless showers, Englefield says the concept is just starting to grow in North America, whereas in other European countries its market share has increased to 25-30 percent in high-end installations.

For J. Sussman Inc., it's about skylights.

"Our company has been in business for 100 years and glass bending for skylights has been an integral part of our operation ," says Sussman.

According to Mike Ondrus, sales and marketing manager for Atwood Mobile Products in Antwerp, Ohio, bent glass trends continue to evolve. Presently, deep radius or sharp bends and different or complex bends are requirements for a number of applications, such as interior glass partitions and glass furniture, he says. He also says he sees an increasing use of frit paints, both solid and translucent, in a wide variety of colors, as well as an increase in frit designs and textured or pattern glass.

Installing Curved Glass
The differences between curved and flat glass do not end with fabrication; there are installation differences as well.

"With curved glass, we have to pay particular attention to tolerances, more so than with flat glass," says Doug Cornell, president of Zephyr Aluminum in Lancaster, Pa.

He points out that matching the tolerances of the outside pressure plate to the curved glass is the critical factor. "If the difference (in tolerance) between the glass and metal is too great, there could be problems," he says.

"We did a large job with Standard Bent Glass on the Kent County Courthouse in Dover, Del.," says Cornell. "We used a soft durometer tape and filled the joint with a silicone sealant to prevent a pressure build-up and possible breakage."

Heinz Flurer, vice president of sales for Beehive Glass in Salt Lake City, Utah, says the radius is also important in bent glass installations.

"The radius of each component must match," he says. "In shower door installations, for example, the door and panel must be perfectly aligned."

Flurer points out that one of the difference in working with curved glass compared to flat glass is that suction cups cannot be used. "The glass must be carried by hand," he cautions.

Regardless of the latest angle on bent or curved glass--new technologies or new trends-the applications remain eye-catchers.

Flurer is a big promoter of curved glass because he believes it has so much to offer in terms of design and aesthetics.

"I think it is beautiful. The added beauty (compared to flat glass) far exceeds the cost, and people do notice the difference."

Alan Goldberg is a contributing writer for USGlass magazine.