Producing glass objects using 3D printing is one of the hardest tasks to achieve with the new method of manufacturing. In fact, only a few researchers around the globe have attempted to even produce the material using additive technology.
Some scientists have made objects by printing molten glass, but the disadvantage is that this requires extremely high temperatures that require specialized equipment to achieve. Other researchers have utilized powdered ceramic particles that they can print at room temperature and then sinter later to make glass, however, the objects created with this method tend to be less complex.
The new method is based on stereolithography, which is a 3D printing technique that was developed back in the 1980s. Researchers were able to create a special resin that contains plastic and organic molecules to which glass precursors bond.
Scientists are able to process the resin using commercially available Digital Light Processing technology. This involves irradiating the resin with UV light patterns. Wherever the light hits the resin, it solidifies because the components are sensitive to light and polymer resin crosslink at the exposed points. The plastic monomers then combine to form a labyrinth-like structure, creating the polymer. The ceramic-bearing molecules finally fill the interstices of this labyrinth.
Engineers can use this newly found technique to build an object up layer by layer. They are able to change a host of variables in each layer, including pore size too. Weak light intensity results in large pores where weak light produces small pores.
“We discovered that by accident, but we can use this to directly influence the pore size of the printed object,” says Kunal Masania of the Complex Materials group at ETH Zurich.
The team was also able to modify the microstructure, layer by layer, by mixing silica borate or phosphate and adding it to the resin. They were also able to create more complex objects from different types of glass, or even combine them in the same object.
Ultimately, the researchers wanted to prove the feasibility of producing glass objects of complex structures using an additive manufacturing process. However, the new technology they’ve created isn’t just a one time gimmick. The team has already filed for a patent and are under negotiations with a Swiss-based glassware dealer who wants to use the technology in their company.