How Corning Created Gorilla Glass

Bryan Gardiner, Wired:

Corning’s one fusion-capable factory in the US is in Harrodsburg, Kentucky. In early 2007, that plant’s seven 15-foot-tall tanks were going full blast, each churning out more than 1,000 pounds per hour of sold-out LCD glass for TV panels. One tank could meet Apple’s initial request. But first the old Chemcor compositions had to be reformulated. The glass not only needed to be 1.3 mm now, it also had to have better visual characteristics than, say, a pane in a telephone booth. Ellison and his team had six weeks to nail it. To be compatible with the fusion process, the glass also needed to be extra stretchy, like chewing gum, at a fairly low temperature. The problem was, anything you do to increase a glass’s gooeyness also tends to make it substantially more difficult to melt. By simultaneously altering seven individual parts of the composition—including changing the levels of several oxides and adding one new secret ingredient—the compositional scientists found they were able to ramp up the viscosity while also producing a finely tuned glass capable of higher compressive stress and faster ion exchange. The tank started in May 2007. By June, it had produced enough Gorilla Glass to cover seven football fields.

A great read.