How It’s Made | Glass Composition | Corning Gorilla Glass

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How it's Made

How it's Made

How it's Made


Corning’s proprietary fusion manufacturing process is at the core of our leadership in glass technology and the cover glass industry. This extraordinarily precise, highly automated draw process produces a thin sheet cover glass with pristine surface quality, outstanding optical clarity and inherent dimensional stability – qualities essential for cover glass for consumer applications.

The process begins when raw materials are blended into a glass composition, which is melted and conditioned. The molten glass is fed into a trough called an “isopipe,” overfilling until the glass flows evenly over both sides. It then rejoins, or fuses, at the bottom, where it is drawn down to form a continuous sheet of flat glass that is so thin it is measured in microns. The glass is untouched by human hands or anything else that will introduce flaws into the surface.

This same fusion process is at the heart of Corning’s industry-leading LCD glass. The composition of Corning® Gorilla® Glass enables a deep layer of chemical strengthening through an ion-exchange process where individual glass parts are cut from the “mother sheet” and undergo an ion-exchange process.


Ion exchange is a chemical strengthening process where large ions are “stuffed” into the glass surface, creating a state of compression. Gorilla Glass is specially designed to maximize this behavior. The glass is placed in a hot bath of molten salt at a temperature of approximately 400 degrees C. Smaller sodium ions leave the glass, and larger potassium ions from the salt bath replace them. These large ions take up more room and are pressed together when the glass cools, producing a layer of compressive stress on the surface of the glass. Gorilla Glass’ composition enables the potassium ions to diffuse far into the surface, creating high compressive stress deep into the glass. This layer of compression creates the surface that is more resistant to damage.

Corning’s innovations don’t end on the manufacturing floor. One of Corning's greatest strengths is our focus on developing the technology behind the glass. Our research has delivered such life-changing innovations as the glass envelope for Edison's light bulb, the glass envelope for cathode ray picture tubes (CRTs) and liquid crystal displays (LCDs), as well as the first low-loss optical fiber capable of use in telecommunications. We continue to investigate new glass compositions and process innovations at our three major research facilities: Sullivan Park in Corning New York; Corning Technology Center in Shizuoka Japan; Corning Research Center Taiwan in Hsinchu, Taiwan.

Scientists in these facilities work closely with the Gorilla Glass commercial, engineering, and manufacturing staff to anticipate industry trends and deliver new or improved glass technologies that add value to customers’ products and processes. Through this ongoing process, Corning Gorilla Glass continues to lead through glass technology innovation in the fast-paced consumer electronics industry.