A new technology for producing rapid prototypes was one of the highlights of Rapid 2009, held May 12-14 in Schaumburg, IL.
Huntsman Advanced Materials introduced Araldite Digitalis, which is based on new micro-electro mechanical system technology to create three-dimensional objects from photo-curable polymers. The big improvement of the new approach over laser-based stereolithography systems is speed. The head speed of Digitalis is 0.12 to 1.97 inches per second.
"Araldite Digitalis opens the way to a greater range of possible applications and a new era in rapid manufacturing," says Philippe Michaud, global technology director of Huntsman Advanced Materials. "It significantly reduces production times and thereby costs."
There are a few limitations, however. One is system cost. The Digitalis is only offered commercially now in Europe, but the U.S. equivalent cost is around $500,000. Another is lack of materials. Only one material grade is currently available for the new machine. "Araldite Digitalis will grow with customers," says Michaud.
At the heart of Araldite Digitalis is an MLS MicroLightSwitch, a new exposure system that runs via a computer-controlled micro-mechanical shutter system. A large surface area of radiation curable resin is selectively exposed in a single step. Lasers, such as those used in stereolithography, expose one point at a time. In the Huntsman system, light from UV lamps is distributed through fiber optics onto an exposure bar where there are MLS units distributing UV light pixels to the resin surface.
The computer-controlled shutter mechanisms steer the exposure of the UV light to avoid scattering. The illuminating angle is 90 degrees, allowing uniform accuracy. Micro lenses refocus the UV light after leaving the MLS.