CHICAGO — Suppliers of rapid prototyping machines are busy preparing for a day when customers use their equipment to make finished production parts in mere hours — eliminating the need for a mold.
Rapid prototyping could end up replacing injection molding for some low-volume parts with high prices, according to Terry Wohlers, who tracks the rapid prototyping industry at Wohlers Associates Inc. in Fort Collins, Colo.
"The majority of the parts that are injection molded today are not going to be candidates for this technology, but there are enough potential parts out there that it still could be really big," Wohlers said.
That may sound like science fiction to companies used to building a model, cutting a steel mold and cranking up the injection press. But visitors to last month's National Design Engineering Show & Conference in Chicago could catch a glimpse of the future at the booths of DTM Corp., 3D Systems Corp. and Stratasys Inc. All three companies are working on new materials that could make "direct manufacturing" possible.
"We are not there yet, but there are steps being taken to move in that direction," said Suresh Jayanthi, 3D Systems' director of applications development.
Jon Cobb, vice president of marketing at Stratasys, said all the machinery companies are focusing on new materials. ABS is the standard resin used by Stratasys, based in Eden Prairie, Minn.
ABS is a good material, but the ultimate goal is offering a range of materials that replicate other common resins, Cobb said.
"We're looking at much more durable types of plastic" for direct manufacturing, Cobb said.
The trend toward "mass customization" also is pushing rapid prototyping into the world of production. Nowhere is that more apparent than at Align Technologies Inc., a company in Santa Clara, Calif., that pioneered a series of polycarbonate braces to straighten teeth, custom-made for each person. To make the braces, Align digitizes impressions of a set of teeth, then uses rapid prototyping machines to create one-of-a-kind forms that are used to make the final braces.
Align Technology, which went public on the Nasdaq exchange in January, has purchased 10 of 3D Systems' SLA 7000 machines.
Wohlers called the braces the first use of rapid prototyping machines for high-volume production.
"It's an industry first. Without that technology they wouldn't be in business," he said.
Now, several hearing-aid makers are looking at rapid prototyping, Wohlers said.
Some rapid prototyping observers say model making could become obsolete, as companies develop sophisticated computer-aided designs, then go straight to cutting a mold.
However, at the Chicago show, representatives of all three prototyping machine makers were quick to say that in some form, part models should be around for a long time.
Most people like to hold a sample part, to feel it, to watch how the light falls on it.
"When you look at a CAD model on a screen, sure, it looks fine," said Jeff Krinks, a spokesman for 3D Systems. "But you can't always look at every little detail. So we don't think that CAD models will ever go away."
Charles Conner, DTM's marketing communications manager, said people who create new products need models to run physical testing, especially for medical products. Models also are good to show how parts fit together — the so-called form, fit and function routine.
A relatively low price also bodes well for models. Making a model also is quicker and cheaper than ever before, thanks to new technology.
Joe Hiemenz of Stratasys said rapid prototyping machine prices have come down dramatically.
"Models serve the purpose of giving you feedback on how your product works," said Hiemenz, technical communications specialist.
The cost of so-called solid-object printers has dropped to about $50,000. Wohlers predicts even lower prices.
"These machines, I'm absolutely convinced, will someday approach the price of an ink-jet printer. And the price of the materials also will drop."
At the design show, DTM and 3D Systems displayed technology that moves rapid prototyping machines a step closer to direct manufacturing — of parts and metal molds:
3D Systems of Valencia, Calif., introduced a machine called the Viper si2. Like the company's other machines, the Viper uses a laser to build parts, layer-by-layer, from a bath of liquid resin. But while the company traditionally has purchased lasers from outside vendors, for the Viper, 3D engineers created a better laser that projects a highly focused beam of light, according to Jayanthi.
"The market is evolving. Viper is a classic example of how we are responding to the marketplace," Jayanthi said.
By making its own lasers, 3D will be better able to develop customized machines and resin materials so customers can make production-run parts, he said.
Austin, Texas-based DTM showed its new LaserForm ST-100 process, which makes steel molds.
The process makes a mold in two to three days on one of DTM's Sinterstation machines. LaserForm is a powdered metal material with a stainless-steel alloy. A laser fuses the powder into solid parts. After the mold is made, the part goes into an oven to become infiltrated with bronze.
Conner said LaserForm molds can turn out tens of thousands of parts from abrasive materials, such as glass-filled nylon, or 100,000-plus parts from ABS, polypropylene or other standard resins.
DTM says LaserForm marks the first use of a rapid prototyping machine to make molds.