Gorilla Glass- Glass with the power of Gorilla is the unique product from US glass making company Corning. Primarily Gorilla glass features high strength and scratch resistance without compromising the thickness and transparency. These features make Gorilla glass the perfect choice for gadgets like smart phones, PDAs and tablets. Gorilla Glass was an immediate hit when it launched in 2007 and Corning claims now over one billion devices are using Gorilla glass.
Like several other accidental inventions , Gorilla glass also said to be born as a byproduct of an accident. One day in 1952 Don Stookey a scientist of Corning was busy with some experiments. He put a photosensitive glass piece inside a furnace. The temperature of the furnace was set to 600 Degree. At a point of time due to some errors in temperature controller, the temperature did shoot up to 900 degree. In that high temperature Stookey was expecting a melted blob of glass but surprisingly the glass plate was transformed into a ceramic like milky plate. While removing it from furnace it slipped off from the tong and felled to the hard floor. Instead of shattering the piece bounced !. The new material was lighter than Aluminum, harder than steel and many fold stronger than conventional glass. This accidental invention gave birth to first in new family of a new glass- ceramic combo material which opened new business opportunities for Corning. Shortly the company launched a project named “Project Muscle” which resulted the evolution of Gorilla Glass. Earlier it was featured as “Muscled Glass” but till 1990 the same was utilized for industrial, chemical , automotive, pharmaceutical and aviation applications only.
Gorilla glass achieves the strength through the process of ion Exchange. As the name indicates, it is a process of the exchange of ions. At a suitable temperature (Approximately 400 Degree Centigrade) glass is dipped into a bath of hot Potassium salt. At this temperature ion exchange takes place, ie Sodium ions from glass is replaced by the Potassium ions of the salt. Potassium ions are considerably larger than sodium ion. Hence this replacement will compress the glass particle which gives added strength. Normally the ion exchange takes place in glass surface only, but Corning’s special composition (Certain percentage of added Aluminum Oxide) of glass increases the penetration level and the Potassium ions penetrate deep into the glass and replaces Sodium ions. This results high compression level deep into the glass surface.
Journey of Gorilla glass with smartphones actually started from Apple iPhone. Earlier plastic sheets were utilized as smartphone screen , are prone to damage through scratches. Transparency lose through aging and environmental factors were also a cause of concern. Motorola Razr V3 was the first phone featured with a thin toughened glass instead of the conventional plastic screen but it was not from Corning. In 2007 Corning got an order from Steve Jobs to make ultra thin toughened glass panel for iPhones. Within the allotted time frame , they have managed to fulfill the demand of Apple and iPhone has become the first smartphone with Gorilla screen.
Fusion Draw Process
Corning used a unique proprietary Fusion Draw process aka Overflow down draw method for making the extreme thin glass panel than the conventional float glass process. This method offers exceptional surface qualities, transparency and eliminate the grinding and polishing requirements. See this video to learn more about Fusion Draw process
Here we can see that the molten glass (Special composite glass material by Corning) poured into a conical through called isopipe when the molten glass overflows over the two outer walls and rejoins under the isopipe. The edge rollers pull the sheet at a prescribed rate. Faster the pull, thinner the sheet. Edges will be cut away and reminder of the sheet will be with a pristine untouched surface. This ultra thin sheets are not different from the conventional glass sheets in characteristics. As explained earlier, ion exchange process makes this thin glass panels tougher and stronger.
Gorilla Glass 3
Gorilla Glass 3 is the third generation glass from Corning. Gorilla Glass 2 was 20 percent stronger than the first version. Now the Gorilla glass 3, first unveiled at CES 2013 features more scratch resistance and toughness than any other glass panels and their own previous versions. Corning says Gorilla Glass 3 has “Native damage resistance” properties through the unique proprietary chemical combination and manufacturing process.
This new version is three times scratch and damage resistant than Gorilla glass 2. Apart from that 40 percent fewer scratches will be visible to the human eye. Samsung Galaxy S4 is the first Smart phone featured with Gorilla Glass 3.
Devices with Gorilla Glass
Go through this page for the products with Gorilla Glass. However you can see that Apple products are not in the list including iPhone and iPad. Corning says
“Due to customer agreements, we cannot identify all devices that feature Gorilla Glass. Your favorite device may include Gorilla Glass, even if you don’t see it listed. Ask your manufacturer or retailer to learn more”