Page 34 - 3D Metal Printing Summer 2019

3D BACKTALK
How Sustainable Is 3D Printing?
By Louis A. Kren
In 1996, the Smithsonian Institution initiated The Millenni- um Project, a worldwide assemblage of futurists, scholars, business planners and policy makers, to mark the dawn of the 21st century. The group developed a list of global chal- lenges, and provides annual reports on the topic. Looking at the list, it is interesting to find that additive manufacturing (AM) has a role to play in meeting a number of the challenges. Let’s look at just one, sustainability, and see where AM helps. Two facts immediately come to mind: AM reduces material waste as compared to traditional manufacturing processes, and print on demand reduces the need for transportation and related infrastructure.
Consider jet engines as an example. Many of us are familiar with GE’s LEAP engine and the development of the engine’s fuel nozzles. Nozzle complexity necessitated 3D printing as the manufacturing method, and creation of this nozzle is consid- ered a seminal event in the abbreviated history of metal AM. Innovations such as the nozzle design and its build method yielded a single part whereas without AM, 18 separate parts, along with the energy and material needed to traditionally manufacture and assemble, would be needed. Other nozzle stats: 25 percent lighter and much more durable than previous nozzles; and 19 nozzles on a single LEAP engine help reduce fuel consumption and CO2 emissions by 15 percent. The LEAP engine now flies or is set to fly on thousands of aircraft.
Following that success, GE Aviation and its partners turned to turboprops, developing an advanced engine that reduced 855 parts to only 12, with about 35 percent of the new engine produced via 3D printing. The new design cut engine weight by 5 percent and fuel consumption by 20 percent, all while pro- viding 10 percent more power than other engines in its class.
“All 855 pieces had a supply chain associated with them,” Greg Morris, strategy growth leader at GE Aviation told Engineering.com
in 2017. “You add tons of shipping logistics, multiple engineers, multiple prints, multiple CAD files...You’ve cut your logistics down to building in one machine and in one location.”
Fast-forward to July 2019, where the GE9X, already the world’s largest commercial jet engine has been designated the most powerful by the Guinness Book of World Records.
The engine, which GE Aviation developed for Boeing’s new 777X widebody jet, clocked in at 134,300 lb. of thrust during a test run, not far from the 188,000 lb. of thrust commanded by the Soyuz rocket that helped Yuri Gagarin to become the first
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“More study is needed to assess the entire AM sustainability picture, and more must be done.”
human to orbit the Earth. Tech- nologies such as 3D printing and new materials help make the engine 10 percent more fuel- efficient that its predecessor, according to Ted Ingling, general manager for the GE9X engine program.
While realized and potential savings can be immense, more study is needed to assess the entire AM sustainability picture,
and more must be done, according to Reid Lifset, editor-in- chief of Yale University’s Journal of Industrial Ecology, which, in 2017-18, studied AM’s sustainability role in-depth.
“An important implication of the complexity of assessing the environmental dimensions of 3D printing is that its adop- tion and diffusion won't automatically generate net environ- mental benefits,” Lifset wrote in an issue recapping the find- ings. “Like other technologies, environmental considerations need to be integrated into the design and deployment of 3D printing if it is to realize its full contribution to sustainability.”
3D printing is a powerful sustainability tool, and time will tell to what extent.
Senior Editor lkren@3DMPmag.com