The Rapid Evolution of Glass 3D Printing

If you’ve ever seen a glass-blowing demonstration, you’ve probably marveled at what a delicate process it is. The practice is an ancient one, and it’s remained a much-loved art form, even though most glass products are manufactured using machinery now. Prior to the Industrial Revolution, glass-blowing was the main method of producing glass products, but, like every other manufacturing method, glass production has evolved – and it’s still evolving.

Until recently, glass 3D printing was unheard of – but that has changed dramatically over the last few years. Gone are the days when plastic and metal were the only two materials that could be 3D printed – we now have ceramics, sand, food, biological material, and yes, even glass. Glass 3D printing isn’t just a novelty, either. Like other forms of 3D printing, it has several distinct advantages over other methods of fabrication, and one big one is that 3D printing is capable of producing complex shapes and forms that other manufacturing methods can’t handle. This, of course, is great news for glass artists, but also for manufacturers, who can create glass items with embedded channels for microfluidics, for example, among other purposes.

Glass has been in the works in the 3D printing world for some time, with developments tracing back to around 2009 and efforts popping up from time to time around the world. In 2015, we heard about the emergence of an Israeli company called Micron3DP. The startup wowed the 3D printing world with its complex glass items, 3D printed at temperatures of up to 1640°C. Micron3DP’s 3D printing technology is similar to FFF, only much, much hotter, and capable of printing two types of glass materials: soda lime and borosilicate. The company hopes to develop additional glass materials in the future, too. Micron3DP took a lot of time to develop its technology, and it shows: the glass 3D printer is fast, and capable of producing items with very high resolution.

Earlier this year, Micron3DP installed the first alpha units of its glass 3D printer in its own facility, and plans to begin shipping beta units by the end of this year. The company will be showcasing the printer at formnext, which is taking place in November.

Shortly after Micron3DP announced its technology, it was followed by MIT, namely the Mediated Matter group and the MIT Glass Lab, which teamed up to develop a glass 3D printer and experiment with 3D printing glass in a project titled G3DP, or Glass 3D Printing. The printer involves a kiln into which glass is placed and heated to a temperature of 1900ºF. The melted glass then passes through a nozzle, which extrudes it to cool and harden. Again, it’s similar to FFF 3D printing, and the project studied 3D printed glass as both an art and a science.

G3DP2, however, took a larger approach – literally. The second Glass 3D Printing project explored 3D printing glass at architectural dimensions with a new, large-scale 3D printer.

“This new manufacturing platform includes a digitally integrated thermal control system—to accompany the various stages of glass forming—as well as a novel 4-axis motion control system permitting flow control, spatial accuracy and precision, and faster production rates with continuous deposition of up to 30kg of molten glass,” the project group explained.

The capabilities of this second glass 3D printer were demonstrated earlier this year in GLASS II, an installation at Milan Design Week consisting of several three-meter-tall 3D printed glass columns.

Not all glass 3D printers resemble FFF machines, though. Earlier this year, researchers at the Karlsruhe Institute of Technology 3D printed glass using an SLA process, the first time anyone has done so. What was really remarkable about that was not only that they had used SLA, but that they had used a commercial SLA 3D printer to do so, rather than building a new specialized printer for the project. The researchers used the technology to 3D print several tiny, intricate objects, demonstrating the fine resolution and complex shapes that can be created through 3D printing.

Those aren’t the only advantages, however. According to the KIT researchers, their glass 3D printing process is faster than traditional methods of glass production, and it doesn’t require chemical etching, which can be hazardous. They 3D printed the items with glass powder suspended in a polymer resin; the printed objects were then heated in a high-temperature oven, where the polymer was burned away, leaving pure glass.

Meanwhile, Lawrence Livermore National Laboratory (LLNL) developed a method for 3D printing glass using direct ink writing. Unlike FFF glass 3D printing, high temperatures weren’t needed for this form of printing; in fact, the glass could be 3D printed at room temperature, using an ink formulated from concentrated suspensions of silica particles. This method was used specifically to create glass for optical applications such as lasers. 3D printing allowed for easier, cheaper lens fabrication, and also enabled composition gradients that aren’t available on the market.

The specialized method developed by LLNL also created lenses with a clarity not found in other forms of 3D printed glass, thanks to a special thermal treatment and polish.

Glass 3D printing has come a remarkably long way in a short period of time – only a few years ago, it didn’t exist at all, and now, it’s being developed and perfected by a number of organizations, using a number of different methods. The applications of 3D printed glass are many, from art and architecture to optics and microfluidics. 3D printing isn’t likely to replace other methods of glass manufacture, but it can certainly achieve some objectives that traditional manufacturing cannot, and is thus invaluable for certain applications. It may also take its place alongside glass-blowing as a demonstration to wow children on field trips.

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