Both companies were chasing the same thing: the enormous market for flat glass. While Pilkington was working to develop flat glass, Corning Glass Works was developing a process of its own. Fusion draw produced a continuous sheet of exceptionally thin, pristine glass, but it was too slow to compete. Corning had a novel process with a product.

The company used fusion draw first, in the 1960s to make experimental windshields, then to produce optical-quality lenses for photo-chromic sunglasses. But the most demanding application didn’t come until much later.

In the 1980s, electronics manufacturers needed glass for liquid crystal displays (LCDs) in laptop computers. The glass had to be very thin and extremely flat, with a pristine surface on both sides. Only fusion draw could produce such flawless glass without grinding and polishing. Patience had finally paid off. Fusion draw became the process for making glass for the Computer Age.

Perfect on Both Sides

For some high-tech applications, such as active matrix liquid crystal displays (LCDs), glass must be perfect on both sides. Float glass is of very high quality—but it’s not perfect. The side of the glass that touched the pool of tin is likely to have minor flaws. It’s possible to polish float glass to perfection, but there’s a better solution: fusion draw glass. It’s untouched on both sides.

Fusion draw glass has been used to make optical-quality sunglasses, experimental car windshields, and LCDs for laptop computers. Without glass, laptop computer LCDs wouldn’t be possible. Glass is the only economical, transparent substrate that can survive the high heat and harsh chemicals needed to lay down the display’s electronics.

How Fusion Draw Works

The Corning Museum of Glass
This article was originally published in Innovations in Glass, 1999, pp. 22–23.

Published on October 25, 2011