Airbus has more than 1,000 plastic parts made with Stratasys Fused Deposition Modeling (FDM), an additive manufacturing technology, on the A350.

FDM in aerospace has been used for interior, noncritical parts; typically, light-load cabin parts, such as wall panels, cabinet doors and latches, and similar parts. “In the future, we see the technology evolving to allow for printing of detailed decorative interior elements, interior structures and then interior structures with embedded electronics,” predicts Scott Sevcik, head of aerospace, defense and automotive solutions at Stratasys.

Stratasys FDM extrudes semi-molten thermoplastics in layers as fine as five-thousandths of an inch, and uses Ultem 9085 thermoplastics for aerospace applications (shown in photo above). The technique avoids the high costs and delays of production tooling. Furthermore, “You can build the part you really want, not be compromised by limitations of traditional manufacturing processes,” Sevcik explains. FDM allows designers to create part geometries that would simply be impossible to make with traditional manufacturing techniques.

Ultem parts meet the FAA’s flame, smoke and toxicity standards, yet their light weight reduces fuel consumption. Stratasys procedures ensure the traceability and consistency necessary for certification by the FAA.

Sevcik says FDM is especially economic for the short runs that are typical in the aircraft industry, and for making one-off customized parts. The high strength-to-weight ratio of Ultem yields its fuel-saving lightness. Aerospace firms were one of the early adopters of FDM, so both they and the FAA are very familiar both with FDM and Stratasys.

Among 3-D printing technologies, FDM is noted for the high quality of parts produced. FDM can print with a wide variety of highly durable materials, unlike other 3-D processes, which work with much more limited families of materials. “FDM is uniquely suited to aerospace applications due to its high reliability and repeatability, as well as ability to create thermoplastic parts with dimensional accuracy and stability,” Sevcik argues. “Just as important, Stratasys has a dedicated team of application engineers, material experts and development engineers who come directly from the aerospace industry.” Uniquely, FDM can build semi-hollow parts such as honeycomb structures inside otherwise hollow unmanned aircraft systems (UAS) wings. Semi-hollow wings are light, but the honeycomb yields high strength.

The firm is working with Boeing on an Infinite Build 3-D demonstrator that would print on a vertical plane for practically unlimited part size in the build direction. The airframer is using this system to explore production of low-volume light parts.

Stratasys is also working with Siemens on a Robotic Composite 3-D demonstrator to save labor in and stretch the geometry of composite production. This demonstrator uses eight-axis motion to precisely and automatically place materials for strength, and to speed up production. “This redefines how future light parts will be built, and provides a glimpse into how this technology could be used to accelerate production of parts made from a wide variety of materials,” Sevcik says. The technology enables 3-D printing of high-value composite structures.