Abandoned Glass Process Yields Cutting-Edge Imagery


It was an invention before its time.

In the 1960s, engineers at Corning Glass Works devised an ingenious method for making thin sheets of exceptionally flat glass. They called it fusion draw glass, and they were certain some preeminent product would come of it.

That did happen, eventually. But the intervening years of disappointment show what a gulf can lie between inspiration and application in the world of inventions.

First, the engineers thought their ultra-flat glass was destined to become the material of choice in car windshields. But a competitor with a cheaper method of making windows beat them. Later, they tried using it in sunglass lenses, and that venture foundered, too.

Clint Shay, Stuart Dockerty and their research colleagues at Corning had climbed to a technological mountaintop and, without a business to latch onto, tumbled ingloriously down the other side.

"I spent 11 or 12 years on this thing, I think I'm hot stuff, it's the biggest project in the company and, all of a sudden, boom, it goes down," Shay said. He and Dockerty invented the fusion draw process to form unvaryingly flat, thin glass with an unblemished surface on both sides. "Now we have this process, and what to do with it?"

The answer didn't begin to emerge until the late 1970s. And it wasn't until the 1990s, after Dockerty had died and Shay had retired, that their wondrous glass flowered in the marketplace as a component of active-matrix liquid crystal displays.

Two sheets of this chemically stable glass, separated by a thin layer of liquid crystals, make for slender, high-resolution displays found in a growing assortment of products: watches, gas pumps, personal organizers, video cameras, medical imaging devices, aircraft navigation panels, computers, televisions.

"It's the window to the Information Age in the 21st century," said Ross Young, who analyzes the flat panel display industry for DisplaySearch in Austin, Texas.

In less than a decade, active-matrix LCDs have gained dominance in the laptop computer market. Nearly 90% of today's laptops are fitted with them. Analysts expect that within a decade, half of all new desktop computers will use the technology, up from 4% this year, as well as millions of TVs that can be hung on the wall like pictures.

For Corning Inc., as the western New York materials supplier now calls itself, this specialty glass accounts for about $250 million, or 7%, of its annual revenue. Corning commands an estimated 60% of the world market, and sales are forecast to triple in four years.

"Finally I've lived long enough that I can see this thing flying. You have no idea how rewarding that is," said Shay, 77, who has lived near Roanoke, Va., since retiring in the mid-'80s. He continued as a consultant with the company until last year.

"You have to let these things incubate. As soon as you put a manager hat on, you want inventions to come along when the business is ripe, but they don't."

Fusion draw glass was inspired by a concept that was long celebrated in science fiction: the flat-screen TV.

In the 1950s, most of Corning's profits flowed from molding glass for the TV cathode-ray tube. While famous for entwining glass innovations in potent technologies--from the light bulb to today's fiber optics--the "scientific glass company" knew it needed another money-spinner to fall back on.

Before long, a Corning chemist invented heat-defying glass-ceramic used in cookware, and new profits emerged. Shay and his small research team, meanwhile, were forging ahead in the search for a lucrative sheet glass.

By pumping hot glass into a trough and allowing it to overflow on both sides, they found the spills flowed back together and fused seamlessly. Because the glass touching the trough wound up in the interior, the surface was flawless.

"It's probably the only process where you can make a sheet of glass that has never been touched by anything except the atmosphere," said Tom Seward, a glass science professor at Alfred University who worked for Corning for 30 years.

Unlike other sheet glass, this one didn't need grinding or polishing. And Dockerty found a way to control its thickness precisely by selectively cooling the stiffening molten material as it fell from the trough.

Also coming into play were earlier Corning discoveries about how to create glass unaltered by heat, devoid of internal defects and extremely thin. The glass in LCDs is typically 0.7 millimeter thick.

Their invention, however remarkable, was not instantly marketable.

They thought it would work well in the windshield market. With the government cracking down over safety, auto makers were seeking ways to prevent injuries from windshields that shattered into jagged shards.

Corning managed to get a chemically strengthened fusion draw glass into the American Motors' Hornet, and for a while the company hoped its glass would dominate the U.S. market for windshields.

But then British rival Pilkington Bros. came along with a revolutionary and far cheaper way to mass-produce car windows. Pilkington drew its sheet glass by floating molten glass on a pool of liquid tin.

Corning took another beating when it adapted its method to manufacture photochromic sunglasses. Within a decade, the business failed in the retail market.

The real breakthrough came in the 1980s when Japanese electronics companies started looking for flat, optical-quality, micro-thin glass free of alkalis that contaminate liquid crystals.

In liquid crystal displays, transistors in the form of a film replace the TV's vacuum tube in amplifying current, and the crystals allow light to pass through via the selective use of electricity. The result is an unsullied, photo-quality, full-color picture.

The monitors are not only less bulky, they're far lighter. The glass tube in a 19-inch TV weighs 24 pounds, but the equivalent LCD glass weighs just three-quarters of a pound.

In Japan, 15-inch LCD TVs have begun popping up in stores for around $1,500 each, and a 20-inch model is promised within months. Bigger TVs are on their way.

Shay said the success of fusion draw glass, however belated, is a gratifying end to a satisfying, challenging career.

"I'm somewhat embarrassed that I lived long enough and the business came along and I'm getting credit for this success," he said. "These things don't happen in flashes. There's thousands of people involved."

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