We like to think of technology as always being forward looking. It’s supposed to be about nanoparticles and the Cloud, not steam engines and the telephone exchange. But every now and again the past reaches out, taps the 21st century on the shoulder and says, “Have a look at this.” That’s what happened to Professor Stephen Hoskins, Director of the University of West England, Bristol's Centre for Fine Print Research. He is currently working on a way of printing 3D ceramics that are self-glazing, thanks to a 7,000-year old technology from ancient Egypt.
Working under a grant from the Arts and Humanities Research Council (AHRC), Hoskins and Research Fellow David Huson have been developing a 3D ceramic printing process that can build very finely detailed, complex structures to industrial specifications and standards. The process works by depositing a layer of wet ceramic material layer by layer. As each layer is printed, the printer table drops, a layer of powder is deposited to support the object, and the process repeats.
Once the object is printed, the ceramic material is allowed to dry and the powder is carefully brushed away. After this, the object is treated like an ordinary piece of pottery. It’s heated in a kiln for what is known as a “biscuit” firing, then glazed and then fired again. Hoskins wanted to reduce the process to a single firing, so he turned to an ancient material called Egyptian faience.
Also known as Egyptian paste, faience is one of those remarkable crossroads materials that occur now and again in the history of technology. It was invented 7,000 years ago in Egypt, when the Egyptians were still trying to get the hang of pottery and smelting metal. It isn’t actually a ceramic, but rather a paste made of quartz or sand, calcite lime and a mixture of alkalis. Because of this, it can be applied directly to wet clay. When the pottery is fired, the paste turns into a brilliant blue-green glaze reminiscent of lapis lazuli, which the Egyptians used faience as a substitute for.
Because making Egyptian faience is similar to the making of ceramics, glass and metals, it’s an important milestone in the development in each of these technologies, and now it’s helping modern researchers in pushing a new technology forward. For the next three years, Hoskins will be investigating three techniques used by the ancient Egyptians in applying faience. One is an “application glazing,” that is similar to modern glazing methods; “efflorescent glazing,” which uses water-soluble salts; and “cementation glazing,” which involved burying the glazing powder in a protective casing before firing.
If any of these approaches are successful, it will mean the creation of a printable ceramic that can be glazed and fired in one go. However, Hoskins sees the development of printable ceramics as a highly disruptive technology that will have a large impact on both art and manufacturing, and that within 15 years will see decentralized manufacturing of custom ceramic parts to order.
The video below is an interview with Dr. Hoskins about printable ceramics.
Source: UWE Bristol
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