3D printing technology is gradually becoming commonplace and is used in many sectors of human life. However, there are materials for which 3D printing is difficult to apply due to the peculiarities of their structure. In particular, the manufacture of objects using “glass” ink has so far been an insoluble task. A group of scientists from the Swiss Research Center ETH Zurich has approached creating the technology that allows printing glass bulk products.
The two main methods of modern “glass” 3D printing are based on the creation of objects from molten glass or a technique for sintering powdered ceramics, pre-printed at room temperature. Both methods have significant drawbacks: in the first case, this requires extremely high temperatures and heat-resistant equipment; and in the second case, it is extremely difficult to maintain the size and print complex objects precisely.
A team from Switzerland will suggest using light-sensitive resin as ink, which includes liquid plastic and organic molecules into which silicon-containing molecules are embedded.
A new technique is to irradiate the resin with ultraviolet light (digitized light treatment). Plastic monomers combine and form a labyrinth-like structure, creating a polymer, and ceramic-bearing molecules fill the gaps in this labyrinth.
The result is a three-dimensional structure, which is subsequently fired at a temperature of 600°C, burning polymers and leaving a ceramic component of the material. Then the object is fired again at the temperature of 1000°C, which leads to the creation of a dense ceramic structure that is transformed into glass. In this case, the object is compressed in volume and this printing property should be taken into account by the designer of 3D glass printing.
The technology is at the initial stage of testing and is still available for the manufacture of small products, but with accurate dimensions and complex shape. Pore size control is also available by varying the intensity of ultraviolet radiation. The physicochemical properties of the printed products can be changed by adding salts of boric acid and phosphates to the resin. Currently, the new technique has already attracted a major Swiss manufacturer of glassware.
