Rapid processes gaining ground
 EOSINT P 700, with a capacity of 29 by 17 by 22 inches. |
When Wohlers Associates Inc. released its most recent findings, “Wohlers Report 2007,” an in-depth global study on the state of the 3D printing, additive fabrication, and rapid manufacturing industry, it revealed that average unit (machine) sales growth, compounded annually, was 37.4% over the past 18 years. Annual sales have grown by more than 26 times—157 units to 4165 units—from 1993 to 2006.
Wohlers Associates has been tracking the developments and trends in additive fabrication, also known as rapid prototyping, since 1988. “The popularity of 3D printers is driving the growth of the industry,” said Wohlers, principal author of “Wohlers Report 2007” and president of Wohlers Associates. “3D printing grew from nothing to nearly 15% of the installed base in its first four years, and represents 68% of the total number of additive systems installed during this period.” 3D printers are low-cost variations of additive systems that are office friendly, easier to use, and less expensive to operate.
The report also reveals that an estimated 77.4% of the 3D printers sold in 2006 came from Stratasys and Z Corp. Additive systems from these two companies have been the most popular in recent years, the report notes, and have led much of the industry’s growth.
Rapid manufacturing—the direct production of finished goods from additive fabrication—is the next frontier, says Wohlers in the report. “Many companies in the aerospace, motor sports, medical, dental, and consumer product industries are now using additive processes for custom and short-run production, and we believe that rapid manufacturing will eventually grow to become the largest application of additive fabrication,” Wohlers said.
Stratasys Inc. (Minneapolis, MN) a maker of rapid prototyping and direct digital manufacturing systems, recently announced a new build option that increases throughput up to 50% compared with previously available options. This enhancement affects the Fuse Deposition Modeling (FDM) and FDM Vantage systems using ABS plastic. The exact throughput improvement will depend on part geometry, and average speed improvement is 40%. The new build option employs a new layer thickness, measuring 0.013 inch (0.330mm), which is best suited to larger geometry, where the highest resolution is not required or when faster speed is needed. FDM layer-thickness options now include 0.005, 0.007, 0.010, and 0.013 inch (0.127, 0.178, 0.254, and 0.330 mm).
“Users can select layer-thickness options to tailor their part’s surface finish, feature detail, and build-speed to the job at hand,” said Fred Fischer, product marketing manager for Stratasys. “The new ‘13 slice’ option provides more flexibility, in that with one system you can build anything from very fine, intricate parts like cell-phone pieces to a large engine block. These options will also give more choice for those doing direct digital manufacturing.”
While more processors and mold manufacturers are finding the value in various forms of rapid prototyping and rapid manufacturing, getting them to adapt RP/ RM into their business models has been an education process. Jim Fendrick, general manager for EOS North America (Novi, MI), said that while the market has been quite receptive to the company’s presence in North America, attracting the attention of moldmaking companies and processors with the advantages of RP and RM hasn’t been easy. “It’s really about educating them as to the benefits and the value that this can provide,” he said in an interview at EOS’s North American Tech Center in Novi.
“We’ve backed away from mold, tool-and-die shops somewhat, primarily because of a reluctance of those types of companies to adopt this technology,” said Fendrick. “When the EOS DMLS [direct metal laser sintering] technology was introduced, we brought with it more usable materials such as the M270 and tool steels, which opened up opportunities more for metal parts than molds. It’s been readily accepted for producing metal parts for the aerospace and medical industries.”
However, Linear Mold & Engineering (Livonia, MI), is a moldmaker that offers a variety of RP and RM services including DMLS, stereolithography (SLA), selected laser sintering (SLS), urethane parts and silicone tooling, and composite and hybrid tooling. The company purchased its first EOSINT M 270 machine from EOS last year, and recently purchased a second M 270 for titanium components.
Plastic laser sintering is available in three systems from EOS. The Formiga P 100 is a small, fast, efficient e-Manufacturing system with a build envelope of 200 mm x 250 mm x 330 mm, and produces plastic products from polyamide or polystyrene within a few hours and directly from CAD data. The EOSINT P 390 can handle a broad range of plastic laser sintering solutions, building end products and fully functional parts as well as high-quality patterns for plaster, investment, and vacuum casting in a few hours. The EOSINT P 730 is the next evolution of the P 700, a double-laser system for laser-sintering of plastics, and one of the largest systems available. It builds components layer-by-layer, directly from CAD data, in a single process. The P 730 manufactures a fuel tank with a size of 607 mm by 330 mm by 491 mm (23.9 by 13 by 19.3 inches) in one piece and in just four days.
Currently, EOS has 46 systems installed in North America. Companies adopting the DMLS technology tend to be larger OEMs and service bureaus, such as Morris Technologies Inc. (Cincinnati, OH), a company that uses a variety of rapid prototyping and rapid manufacturing equipment for new-product R&D.
“The initial goal in the moldmaking arena was to produce molds and tooling that could mold on to 1000 pieces,” says Bill Noack, President of Morris Technologies. “Anything higher than that is not a fit for us.”
The RP/RM industry “has received a bit of a black eye because there were some technologies that didn’t deliver what they promised, such as SLA molds, for example,” Noack explains. “Some new technologies that look promising are the SLA Nanotool and the SLS Laserform.”
With respect to producing rapid molds, the benefit of the DMLS process is that there are no secondary steps required. “Your mold comes out clean and needing very little polishing,” Noack says. The EOSINT M 270 machine allows Morris Technologies to build tools with much thinner walls—less than 0.0010 inch. Morris Technologies has six machines, and is the largest producer of DMLS parts in the U.S.
Noack showed off a mold that can be hand carried. The mold was a handle mold in which the customer needed polycarbonate parts in two weeks or less. Morris Technologies built the mold in 11 hours at a cost of $5200, reducing both the cost and time compared to the Chinese quote.
EOS offers a number of metal powder materials including titanium and DM20, a fine-grained bronze-based metal powder, similar to aluminum, and porous. “The key is to utilize the right material for the right application,” said Noack.