Filip Novotny Shortly before the launch of the first iPhone, Steve Jobs called for his employees and was furious about a bunch of scratches that appeared on the prototype he was using after a few weeks. It was clear that it was not possible to use standard glass, so Jobs teamed up with the glass company Corning. However, its history goes back deep into the last century.
It all started with one failed experiment. One day in 1952, Corning Glass Works chemist Don Stookey tested a sample of photosensitive glass and placed it in a 600°C furnace. However, during the test, an error occurred in one of the regulators and the temperature rose to 900 °C. Stookey expected to find a molten lump of glass and a destroyed furnace after this mistake. Instead, however, he found that his sample had turned into a milky white slab. As he tried to grab her, the pincers slipped and fell to the ground. Instead of shattering on the ground, it rebounded.
Don Stookey didn't know it at the time, but he had just invented the first synthetic glass ceramic; Corning later called this material Pyroceram. Lighter than aluminum, harder than high-carbon steel, and many times stronger than ordinary soda-lime glass, it soon found use in everything from ballistic missiles to chemical laboratories. It was also used in microwave ovens, and in 1959 Pyroceram entered homes in the form of CorningWare cookware.
The new material was a major financial boon for Corning and enabled the launch of Project Muscle, a massive research effort to find new ways to toughen glass. A fundamental breakthrough occurred when researchers came up with a method of strengthening glass by immersing it in a hot solution of potassium salt. They found that when they added aluminum oxide to the glass composition before immersing it in the solution, the resulting material was remarkably strong and durable. The scientists soon began throwing such hardened glass from their nine-story building and bombarding the glass, known internally as 0317, with frozen chickens. The glass could be bent and twisted to an extraordinary degree and also withstood a pressure of about 17 kg/cm. (Ordinary glass can be subjected to a pressure of about 850 kg/cm.) In 1, Corning began offering the material under the name Chemcor, believing it would find applications in products such as telephone booths, prison windows, or eyeglasses.
Although there was a lot of interest in the material at first, sales were low. Several companies have placed orders for safety glasses. However, these were soon withdrawn due to concerns about the explosive way in which the glass could shatter. Chemcor seemingly could become the ideal material for automobile windshields; although it appeared in a few AMC Javelins, most manufacturers were unconvinced of its merits. They did not believe that Chemcor was worth the cost increase, especially since they had been successfully using laminated glass since the 30s.
Corning invented a costly innovation that no one cared about. He was certainly not helped by the crash tests, which showed that with windshields "the human head shows significantly higher decelerations" - the Chemcor survived unscathed, but the human skull did not.
After the company unsuccessfully tried to sell the material to Ford Motors and other automakers, Project Muscle was terminated in 1971 and the Chemcor material ended up on ice. It was a solution that had to wait for the right problem.
We are in the state of New York, where the Corning headquarters building is located. The director of the company, Wendell Weeks, has his office on the second floor. And it is precisely here that Steve Jobs assigned the then fifty-five-year-old Weeks a seemingly impossible task: to produce hundreds of thousands of square meters of ultra-thin and ultra-strong glass that did not exist until now. And within six months. The story of this collaboration - including Jobs' attempt to teach Weeks the principles of how glass works and his belief that the goal can be achieved - is well known. How Corning actually managed it is no longer known.
Weeks joined the firm in 1983; earlier than 2005, he occupied the top post, overseeing the television division as well as the department for special specialized applications. Ask him about glass and he will tell you that it is a beautiful and exotic material, the potential of which scientists have only just begun to discover today. He will rave about its "authenticity" and pleasantness to the touch, only to tell you about its physical properties after a while.
Weeks and Jobs shared a weakness for design and an obsession with detail. Both were attracted to big challenges and ideas. From the management side, however, Jobs was a bit of a dictator, while Weeks, on the other hand (like many of his predecessors at Corning), supports a freer regime without too much regard for subordination. "There is no separation between me and the individual researchers," says Weeks.
And indeed, despite being a big company—it had 29 employees and $000 billion in revenue last year—Corning still acts like a small business. This is made possible by its relative distance from the outside world, a death rate hovering around 7,9% every year, and also the company's famous history. (Don Stookey, now 1, and other Corning legends can still be seen in the hallways and labs of the Sullivan Park research facility.) “We're all here for life,” smiles Weeks. "We have known each other here for a long time and have experienced many successes and failures together."
One of the first conversations between Weeks and Jobs actually had nothing to do with glass. At one time, Corning scientists were working on microprojection technology - more precisely, a better way to use synthetic green lasers. The main idea was that people don't want to stare at a miniature display on their mobile phone all day when they want to watch movies or TV shows, and projection seemed like a natural solution. However, when Weeks discussed the idea with Jobs, the Apple boss dismissed it as nonsense. At the same time, he mentioned that he is working on something better – a device whose surface is entirely made up of a display. It was called the iPhone.
Although Jobs condemned green lasers, they represent the "innovation for innovation's sake" that is so characteristic of Corning. The company holds such respect for experimentation that it invests a respectable 10% of its profits in research and development every year. And in good times and bad. When the ominous dot-com bubble burst in 2000 and Corning's value fell from $100 a share to $1,50, its CEO assured researchers not only that research was still at the heart of the company, but that it was research and development that kept it going. bring back to success.
"It's one of the very few technology-based companies that is able to refocus on a regular basis," says Rebecca Henderson, a Harvard Business School professor who has studied Corning's history. "That's very easy to say, but hard to do." Part of that success lies in the ability to not only develop new technologies, but also to figure out how to start producing them on a massive scale. Even if Corning is successful in both of these ways, it can often take decades to find a suitable – and sufficiently profitable – market for its product. As Professor Henderson says, innovation, according to Corning, often means taking failed ideas and using them for a completely different purpose.
The idea to dust off Chemcor's samples came about in 2005, before Apple even got into the game. At the time, Motorola released the Razr V3, a clamshell cell phone that used glass instead of the typical hard plastic display. Corning formed a small group tasked with seeing if it was possible to revive type 0317 glass for use in devices such as cell phones or watches. The old Chemcor samples were around 4 millimeters thick. Maybe they could be thinned out. After several market surveys, the company's management became convinced that the company could make a little money from this specialized product. The project was named Gorilla Glass.
By 2007, when Jobs expressed his ideas about the new material, the project did not get very far. Apple clearly required massive quantities of 1,3mm thin, chemically toughened glass – something no one had created before. Could Chemcor, which has not yet been mass-produced, be linked to a manufacturing process that could meet the massive demand? Is it possible to make a material originally intended for automotive glass ultra-thin and at the same time maintain its strength? Will the chemical hardening process even be effective for such glass? At the time, no one knew the answer to these questions. So Weeks did exactly what any risk-averse CEO would do. He said yes.
For a material so notorious as to be essentially invisible, modern industrial glass is remarkably complex. Ordinary soda-lime glass is sufficient for the production of bottles or light bulbs, but is very unsuitable for other uses, as it can shatter into sharp shards. Borosilicate glass such as Pyrex is excellent at resisting thermal shock, but its melting requires a lot of energy. Additionally, there are only two methods by which glass can be mass-produced – fusion draw technology and a process known as floatation, in which molten glass is poured onto a base of molten tin. One of the challenges that the glass factory has to face is the need to match a new composition, with all the required features, to the production process. It's one thing to come up with a formula. According to him, the second thing is to make the final product.
Regardless of the composition, the main component of glass is silica (aka sand). Since it has a very high melting point (1 °C), other chemicals, such as sodium oxide, are used to lower it. Thanks to this, it is possible to work with glass more easily and also to produce it more cheaply. Many of these chemicals also impart specific properties to the glass, such as resistance to X-rays or high temperatures, the ability to reflect light or disperse colors. However, problems arise when the composition is changed: the slightest adjustment can result in a radically different product. For example, if you use a dense material such as barium or lanthanum, you will achieve a reduction in the melting point, but you run the risk that the final material will not be completely homogeneous. And when you strengthen the glass, you also increase the risk of explosive fragmentation if it breaks. In short, glass is a material ruled by compromise. This is precisely why compositions, and especially those tuned to a specific production process, are such a highly guarded secret.
One of the key steps in glass production is its cooling. In the mass production of standard glass, it is essential to cool the material gradually and uniformly to minimize internal stresses that would otherwise make the glass more easily broken. With tempered glass, on the other hand, the goal is to add tension between the inner and outer layers of the material. Glass tempering can paradoxically make the glass stronger: the glass is first heated until it softens and then its outer surface is sharply cooled. The outer layer shrinks quickly, while the inside remains still molten. During cooling, the inner layer tries to shrink, thus acting on the outer layer. A stress is created in the middle of the material while the surface is densified even more. Tempered glass can be broken if we get through the outer pressure layer into the stress area. However, even the hardening of glass has its limits. The maximum possible increase in the strength of the material depends on the rate of its shrinkage during cooling; most compositions shrink only slightly.
The relationship between compression and stress is best demonstrated by the following experiment: by pouring molten glass into ice water, we create teardrop-like formations, the thickest part of which is able to withstand tremendous amounts of pressure, including repeated hammer blows. However, the thin part at the end of the drops is more vulnerable. When we break it, the quarry will fly through the entire object at a speed of over 3 km/h, thus releasing internal tension. Explosively. In some cases, the formation can explode with such force that it emits a flash of light.
Chemical tempering of glass, a method developed in the 60s, creates a pressure layer just like tempering, but through a process called ion exchange. Aluminosilicate glass, such as Gorilla Glass, contains silica, aluminum, magnesium, and sodium. When immersed in molten potassium salt, the glass heats up and expands. Sodium and potassium share the same column in the periodic table of elements and therefore behave very similarly. The high temperature from the salt solution increases the migration of sodium ions from the glass, and potassium ions, on the other hand, can take their place undisturbed. Since potassium ions are larger than hydrogen ions, they are more concentrated in the same place. As the glass cools, it condenses even more, creating a pressure layer on the surface. (Corning ensures even ion exchange by controlling factors such as temperature and time.) Compared to glass tempering, chemical hardening guarantees a higher compressive stress in the surface layer (thus guaranteeing up to four times the strength) and can be used on glass of any thickness and shape.
By the end of March, the researchers had the new formula almost ready. However, they still had to figure out a method of production. Inventing a new production process was out of the question as it would take years. In order to meet Apple's deadline, two of the scientists, Adam Ellison and Matt Dejneka, were tasked with modifying and debugging a process that the company was already using successfully. They needed something that would be able to produce huge quantities of thin, clear glass in a matter of weeks.
Scientists basically had only one option: the fusion draw process. (There are a lot of new technologies in this highly innovative industry, the names of which often do not yet have a Czech equivalent.) During this process, molten glass is poured onto a special wedge called an "isopipe". The glass overflows on both sides of the thicker part of the wedge and joins again on the lower narrow side. It then travels on rollers whose speed is precisely set. The faster they move, the thinner the glass will be.
One of the factories that uses this process is located in Harrodsburg, Kentucky. At the beginning of 2007, this branch was running at full capacity, and its seven five-meter tanks brought 450 kg of glass intended for LCD panels for televisions into the world every hour. One of these tanks could be enough for the initial demand from Apple. But first it was necessary to revise the formulas of the old Chemcor compositions. Not only did the glass have to be 1,3 mm thin, it also had to be significantly nicer to look at than, say, a telephone booth filler. Elisson and his team had six weeks to perfect it. In order for the glass to be modified in the "fusion draw" process, it is necessary for it to be extremely flexible even at relatively low temperatures. The problem is that anything you do to improve elasticity also substantially increases the melting point. By tweaking several existing ingredients and adding one secret ingredient, the scientists were able to improve the viscosity while ensuring a higher tension in the glass and faster ion exchange. The tank was launched in May 2007. During June, it produced enough Gorilla Glass to fill over four football fields.
In five years, Gorilla Glass has gone from being a mere material to an aesthetic standard—a tiny divide that separates our physical selves from the virtual lives we carry around in our pockets. We touch the outer layer of glass and our body closes the circuit between the electrode and its neighbor, converting movement into data. Gorilla is now featured in more than 750 products from 33 brands worldwide, including laptops, tablets, smartphones and televisions. If you regularly run your finger over a device, you're probably already familiar with Gorilla Glass.
Corning's revenue has skyrocketed over the years, from $20 million in 2007 to $700 million in 2011. And it looks like there will be other possible uses for glass. Eckersley O'Callaghan, whose designers are responsible for the appearance of several iconic Apple Stores, has proven this in practice. At this year's London Design Festival, they presented a sculpture made only of Gorilla Glass. This could eventually reappear on automotive windshields. The company is currently negotiating its use in sports cars.
What does the situation around glass look like today? In Harrodsburg, special machines routinely load them into wooden boxes, truck them to Louisville, and then send them by train toward the West Coast. Once there, the sheets of glass are placed on cargo ships and transported to factories in China where they undergo several final processes. First they are given a hot potassium bath and then they are cut into smaller rectangles.
Of course, despite all its magical properties, Gorilla Glass can fail, and sometimes even very "effectively". It breaks when we drop the phone, it turns into a spider when it's bent, it cracks when we sit on it. It's still glass after all. And that's why there's a small team of people in Corning who spend most of the day breaking it down.
“We call it the Norwegian hammer,” says Jaymin Amin as he pulls a large metal cylinder out of the box. This tool is commonly used by aeronautical engineers to test the strength of the aluminum fuselage of aircraft. Amin, who oversees the development of all new materials, stretches the spring in the hammer and releases a full 2 joules of energy into the millimeter-thin sheet of glass. Such force will create a large dent in the solid wood, but nothing will happen to the glass.
The success of Gorilla Glass means several obstacles for Corning. For the first time in its history, the company has to face such high demand for new versions of its products: every time it releases a new iteration of glass, it is necessary to monitor how it behaves in terms of reliability and robustness directly in the field. To that end, Amin's team collects hundreds of broken cell phones. "The damage, whether it's small or large, almost always starts in the same place," says scientist Kevin Reiman, pointing to an almost invisible crack on the HTC Wildfire, one of several broken phones on the table in front of him. Once you find this crack, you can measure its depth to get an idea of the pressure the glass was subjected to; if you can mimic this crack, you can investigate how it propagated throughout the material and try to prevent it in the future, either by modifying the composition or by chemical hardening.
With this information, the rest of Amin's team can investigate the same material failure over and over again. To do this, they use lever presses, drop tests on granite, concrete and asphalt surfaces, drop various objects onto the glass and generally use a number of industrial-looking torture devices with an arsenal of diamond tips. They even have a high-speed camera capable of recording a million frames per second, which comes in handy for studies of glass bending and crack propagation.
However, all that controlled destruction pays off for the company. Compared to the first version, Gorilla Glass 2 is twenty percent stronger (and the third version should arrive on the market early next year). The Corning scientists achieved this by pushing the compression of the outer layer to the very limit - they were a bit conservative with the first version of Gorilla Glass - without increasing the risk of explosive breakage associated with this shift. Nevertheless, glass is a fragile material. And while brittle materials resist compression very well, they are extremely weak when stretched: if you bend them, they can break. The key to Gorilla Glass is the compression of the outer layer, which prevents cracks from spreading throughout the material. When you drop the phone, its display may not break immediately, but the fall could cause enough damage (even a microscopic crack is enough) to fundamentally impair the strength of the material. The next slightest fall can then have serious consequences. This is one of the inevitable consequences of working with a material that is all about compromises, about creating a perfectly invisible surface.
We're back at the Harrodsburg factory, where a man in a black Gorilla Glass T-shirt is working with a sheet of glass as thin as 100 microns (roughly the thickness of aluminum foil). The machine he operates runs the material through a series of rollers, from which the glass emerges bent like a huge shiny piece of transparent paper. This remarkably thin and rollable material is called Willow. Unlike Gorilla Glass, which works a bit like armor, Willow can be compared more to a raincoat. It is durable and light and has a lot of potential. Researchers at Corning believe the material could find applications in flexible smartphone designs and ultra-thin OLED displays. One of the energy companies would also like to see Willow used in solar panels. At Corning, they even envision e-books with glass pages.
One day, Willow will deliver 150 meters of glass on huge reels. That is, if someone actually orders it. For now, the coils sit idle at the Harrodsburgh factory, waiting for the right problem to arise.
nice article, thanks!
Interesting article :) but I would like to know how the Gorilla glass turned out at Steve's :) how was the demonstration of the project :)... in fact, in my opinion it would be completely at 1 :)
Interesting article :) but I would like to know how the Gorilla glass turned out at Steve's :) how was the demonstration of the project :)... in fact, in my opinion it would be completely at 1 :)
it's in the Steve Jobs book ;)
thank you :)
Nice one! :-)
Nice one! :-)
I really enjoyed reading and learned a lot. Thanks a lot.
Very nice article, thank you for it. The man learned something interesting. Writers from zive.cz and spol could learn something..
This is how I imagine the apple server! Jablickar leads :) thank you
By far the best article on Jablickari this year. And in SJ's CV there was not even a fraction of the information given here. Thanks!
Wait, so the first iPhone already used Gorilla, or what? Otherwise, great article. :)
It is so. They basically switched from plastic to Gorilla Glass at the last minute.
Great article :D …. Does anyone know if he has an iphone 5 gorilla glass 2???
Absolutely great article! Thanks!
That's exactly what I'm waiting for and why I come here. Just more and more often, please!
Great article! More of these and I'll smack in front of the editor and translator!
I admire that at a time when any "serious" news website is primarily looking for unpublished photos of Kate (even domestic servers forgot about Iveta Bartošová for a few days!), Jablíčkář brings informative articles. Thanks! :-)
Frodo
Thanks for the great article, keep it up.
Awesome article! I read it in one sitting :-), like a great detective story (or science fiction, hehe)
Thanks!
Thanks for a great article, I think it's worth investing your time to sleep on something so valuable.
great article! Thanks!
Oh, now I'm totally amazed!
Once again, someone will tell me: "It's always just a stupid phone!".
Somehow, in this otherwise very nicely written article, I'm missing fa Corning's share of weapons supplies for the USAF. Since the 60s, they have supplied their tempered glass to a specific part of the frontal part of the cockpit of fighter jets to increase the protection of the aircraft crew, e.g. in the event of a collision with birds, but of course also against missiles, and if I am not mistaken, they have gathered a lot of information and experience here about the development and production of these materials. And as it happens, it took more than 50 years for these technologies to reach the civilian sector.
Great article, keep it up :-)
Well, such a nicely written technically focused article, ...hats off, thanks.
Jenda Pilsenský
God article!! BTW the Willow glass is interesting... I'm quite interested to see how it behaves when trying to crumple when it's like tin foil ;) and how it fares with scratch resistance.