New Rapid Prototyping Approach Features Fast Build Times

A new technology for producing rapid prototypes was one ofthe 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 createthree-dimensional objects from photo-curable polymers. The big improvement ofthe new approach over laser-based stereolithography systems is speed. The headspeed of Digitalis is 0.12 to 1.97 inches per second.

"Araldite Digitalis opens the way to a greater range ofpossible applications and a new era in rapid manufacturing," says PhilippeMichaud, global technology director of HuntsmanAdvanced Materials. "It significantly reduces production times and therebycosts."

There are a few limitations, however. One is system cost.The Digitalis is only offered commercially now in Europe, but the U.S. equivalentcost is around $500,000. Another is lack of materials. Only one material gradeis currently available for the new machine. "Araldite Digitalis will grow withcustomers," says Michaud.

At the heart of Araldite Digitalis is an MLSMicroLightSwitch, a new exposure system that runs via a computer-controlledmicro-mechanical shutter system. A large surface area of radiation curableresin is selectively exposed in a single step.Lasers, such as those used in stereolithography, expose one point at atime. In the Huntsman system, light from UV lamps is distributed through fiberoptics onto an exposure bar where there are MLS units distributing UV lightpixels to the resin surface. 

The computer-controlled shutter mechanisms steer theexposure of the UV light to avoid scattering. The illuminating angle is 90degrees, allowing uniform accuracy. Micro lenses refocus the UV light afterleaving the MLS.