3D printers — even the desktop FFF (Fused-Filament Fabrication) models common among hobbyists — are something of a miracle for prototyping. Creating a single plastic prototype part used to be a long and expensive process of manually sculpting the part, creating a mold, and casting the plastic. Now, a 3D printer can churn that same part out quickly with little effort. But, large or finely-detailed parts can still take several hours, or even days, to print. This new 3D printing technique is dramatically faster — up to 100 times faster than standard techniques.
This technique is the result of research conducted by engineers from the University of Michigan, and is essentially an optimized adaption of SLA (Stereolithography) 3D printing. SLA 3D printers work by shining a light into a vat of photopolymer resin, which cures the liquid into a solid part. SLA was actually the first patented 3D printing process, and it’s still popular today for parts that require a lot of intricate detail. But, it’s expensive compared to FFF printing, and isn’t particularly speedy.
This new take on SLA printing solves both problems by using a combination of blue and UV light. The researchers developed a special kind of resin that hardens under the blue light, but that resists hardening under UV light. By shining those lights through a glass window on the bottom of the vat of resin in controlled patterns with varying intensity, they can form entire portions of the part at once.
That’s a far more time-efficient approach than printing a part layer-by-layer. In tests, they were able to print 2 meters of material per hour — a massive improvement over the 25 millimeters per hour rate of a traditional SLA 3D printer. And, because it relies on inexpensive UV and blue LED lights, it could be significantly less expensive to make a 3D printer that utilizes this technique compared to a typical SLA printer.