EOS filled materials that contain a hollow filler can reduce weight even more. Don Vanelli, president of EOS-owned Advanced Laser Materials, said:
For many years there wasn't much choice of filled materials on the polymer side: perhaps two or three, mostly nylon, with a choice of adding glass or aluminum as fillers. So we developed new polymers, as well as mixing, blending, or providing secondary processing to make them more usable for a specific application. We aim at low-volume production parts and single customized production parts.
EOS's aerospace customers are now fully utilizing a printer's capacity, helping to make parts less expensive. Vanelli said:
If I turn the machine on and build one part that uses only 10 percent of the space, I could theoretically add another nine parts to fill that space and increase efficiency. Laser sintering has become a viable way to make end-use parts, not just prototypes, so demand is increasing, and the cost is going down. Also, on the hardware side, machine scanning speeds and accuracy are going up, so the time to build a part is getting shorter.
Customers are finding they can do parts consolidation because of laser sintering, said Andrew Snow, director for EOS of North America. They can reduce the overall parts cost and secondary operations for assembly or finishing, or secondary welding and brazing operations. Although the machines are getting better and faster, adopting the technology can also dramatically reduce parts count and inventory.
For example, Northwest UAV Propulsion Systems and its sister company, Northwest Rapid Manufacturing, used EOS's FORMIGA P 100 plastic laser-sintering system to build a complete UAV generator set. The set consists of a combustion engine that drives an electrical generator. It increases fuel capacity with a plastic tank design that maximizes available space and incorporates both the fuel tank and its enclosure in a single part.
In other military applications with a medical slant, DARPA has bought some Stratasys printers for making scaffolds, rib spreaders, and other handheld medical devices used by doctors on the front lines. DeGrange said:
They want to see if it's possible to send a file to a printer in an Afghanistan tent city, build the tool in the machine, and make sure they're sterile. They're working with a special material that can compound particles such as silver into the plastic to kill bacteria.
In Stage 1 studies, DARPA is using Stratasys's uPrint machines to test the concept and the material, but wants to shift to smaller Mojo printers that can run off a HUMVEE's DC power. That would let the technology be deployed in mountains or other remote areas not only in tent cities. "We already have medical-grade ABS plastics that meet ISO 10993 guidelines, but users don't typically run those on the uPrint or the Mojo," said DeGrange. Being able to print on-demand sterile medical tools could also be valuable for disaster areas, search-and-rescue efforts, and first responders.