I've spoken with a number of jewelry designers at our Expo events – people currently using or interested in using 3D printing to produce models for investment casting. In a process dating back thousands of years in origin, investment casting creates a metal object from a non-metal sculpture. A mould is formed around the sculpture and then heated, burning away the sculpture and leaving a hollow mould which can be filled with molten metal. Due to its easy sculpting and melting nature, wax has been a preferred material for centuries and as a result, investment casting was traditionally known as lost-wax casting.
Many (if not most) of today's jewelry manufacturers have incorporated 3D printing into the process. Designers develop their creations using 3D modeling software on a computer instead of sculpting by hand. This method has a number of advantages, including the ability to undo subtractive mistakes or decisions and reuse previous work as a starting point for something new. However, the digital 3D model has to get outside the computer into the physical world, which is where 3D printing enters the picture.
Of the jewelers I've spoken with, some swear by the abilities of liquid resin printers using wax-like materials, touting the detail achievable with SLA-derived technology. I've also talked to individuals who say wax is the only way to go, because it has better burnout properties (the step in the process whereby the model is melted out of the mould).
The EnvisionTEC WaxEra combines both methods. It is a DLP 3D printer with an LED light source that uses wax paste mixed with a photosensitive polymer binder. It provides the burnout properties of wax and the detail of SLA. Known as E-Wax, the material used by the WaxEra is said avoid porosity due to ash content regardless of a model's wall thickness. It also avoids metal flashing due to polymer expansion. E-Wax can be cast in the same tree as traditional wax patterns without the need for a significant change to standard burnout cycles or the use of sophisticated casting equipment.
"We are proud to deliver the very first Digital Light Projection technology based 3D printer that can print with a paste material, opening up the possibility to 3D print using highly filled materials. These new highly filled paste materials will allow EnvisionTEC to penetrate new markets and deliver 3D printing solutions not previously available in the 3D printing space," said Al Siblani, CEO of EnvisionTEC. "Whether you want a highly filled ceramic part for high temperature resistance or a highly filled wax part for direct investment casting, the WaxEra™ brings 3D printing into a new era by delivering innovative 3D printing solutions to an expanding selection of new markets."
More information can be found on the WaxEra page of the EnvisionTEC website.