Thermwood and Boeing have announced that they’ve made a large 3D printed composite part for Boeing’s 777X program. The Thermwood’s LSAM technology was used to make a 20% carbon fiber reinforced ABS part. The part is a “12-foot-long R&D tool.” This demonstrates the possible applications of polymer 3D printing for large parts for aerospace, albeit in experimental tooling.
Boeing’s 777X program will create Boeing’s next-generation long-range wide-body airliners. The 777-8 and 777-9 aircraft will be the mainstays of many point to point long distance fleets of global carriers. The 777-9 will carry over 400 passengers over 13,000 kilometers. Having maxed out composites on its 787 aircraft Boeing is looking to bring its expertise in composite materials to these twin-aisle airliners. With folding wing tips and expected inefficiencies, they will double down on Boeing’s strategy to focus on connecting disparate dots on the earth together with direct flights. This in contrast to the Airbus strategy of efficient short-haul airliners combined with hub and spoke with large A 380’s flying between big cities. Composites were crucial to Boeing’s development of the 787. Boeing was also a very early (think 1995) pioneer in using various 3D printing technologies on many military and civilian platforms. To see these two technologies intertwine in LSAM feels very logical indeed.
Thermwoos’s Large Scale Additive Manufacturing machine and its Vertical Layer Print (VLP) 3D printing technology can make large composite parts. With LSAM a wheel presses down a layer as it is being printed on the previous layer. Print speed depends on the cooling on the polymer itself and the printed part is either printed on a scaffold. The company calls this a “bead board” because the droplets of plastic “beads” are glued to it. LSAM is a very interesting approach that gives us very large but rather rough parts with a good amount of control over layer adhesion.
This particular printed 4 meter part was made in one production run and was intended to save Boeing time. The part also saved on assembly cost. Boeing’s Interiors Responsibility Center (IRC) facility in Everett, Washington now has a Thermwood LSAM machine that it can now use to make parts like this. These kinds of parts could aid in hand layup or assembly operations of existing parts. The high stiffness of the ABS parts should be helpful in that area. One of the amazing things is that with LSAM Thermwood prints ABS at room temperature and through the scaffold and pressing the layer down seems to have little problems with warping. Printing at room temperature would seem to limit the technology somewhat. It would seem to be difficult for the company to use materials such as PEI which are used for end use in aerospace because of the temperatures used. Jason Susnjara of Thermwood told us however that, “We do print other materials such as Ultem, PPS, PSU and PESU.” This is a great step in making large-scale tooling and parts for industry.
A further step where large cabin parts would themselves be made with 3D printing would be even more exciting. For that, a flame retardant material that is certified for civilian airliners will have to be used. A material such as PEEK, PEI or PEKK could perhaps fulfill that purpose but it is unclear at the moment how we would get the heated chamber thermal control to make parts this size out of those materials. Or if LSAM could be adapted to print the right grades of these materials. Simultaneously Boeing would want to instead of carbon fiber which is nasty to make for its employees and is impossible to recycle use a more environmentally friendly material that could be recycled. A hemp PEKK, silk PEI or flax PEEK may sound like a perfectly silly idea but something like them would let Boeing continue to win in 3D printing and composites.