The international ivory trade has been banned for over 30 years now, which means that technicians restoring ivory artifacts have to get creative in finding alternative materials. A new 3D-printable substance known as Digory appears to fit the bill nicely.
Developed via a partnership between the Vienna University of Technology and spinoff company Cubicure, Digory initially takes the form of a liquid synthetic resin containing calcium phosphate particles and silicon oxide powder.
In a variation on the stereolithography 3D printing process, the resin is first poured into a transparent vat. An ultraviolet laser beam is then shone into the resin through the bottom of that vat, moving back and forth through the liquid. As it does so, the resin that's selectively exposed to the UV light solidifies onto the underside of a print bed located above it. That bed gradually moves up through the vat while the laser continues its movements, building objects up one layer of hardened resin at a time.
Once the item has been printed, it is then polished and dyed to match the color of the artifact being restored. So far, colorants such as black tea have produced good results. According to the scientists, the finished product not only looks just like ivory – complete with its translucent quality – but it also replicates ivory's strength and stiffness.
The technology has already been utilized to replace lost ivory ornamentation on a 17th-century state casket, located in a parish church in the Austrian town of Mauerbach. It is hoped that once developed further, Digory could be used not only as a restoration material, but also as a means of displacing and outcompeting the expensive elephant ivory that is still illegally sold by poachers.
A paper on the research was recently published in the journal Applied Materials Today.
Source: Vienna University of Technology
