Lufthansa Technik AG is not only involved in maintenance and repair in the aviation sector, but also sells aviation products and aircraft components to major original equipment manufacturers (OEMs), such as Airbus and Boeing.
One of these product lines is exit route markings for aircraft interiors, which are produced in an innovative way with the help of 3D printed manufacturing tools.
In an interview with Ulrich Zart, project engineer at Lufthansa Technik AG, we discussed how the company uses these 3D printed tools as consumables in production and how 3D printing makes process optimization more flexible.
Outbound route markings for Airbus, Boeing and others As one of the world's largest providers of aviation MRO (maintenance, repair and overhaul) services, Lufthansa Technik AG already makes extensive use of additive manufacturing. Since 2018, a sector in the company is responsible for the research and development of various 3D printing technologies for the manufacture of aerospace products, as well as tools and devices for their production. The largest buyers of these aircraft components are primarily large OEMs, such as Airbus and Boeing.
One of Lufthansa Technik's products that uses 3D printing is the Guide U exit route markings for aircraft interiors. These innovative floor markings are photoluminescent, meaning they are equipped with self-illuminating color pigments that fill with normal cabin light and continue to glow in the dark in an emergency without electricity. Self-illuminating strips along the rows of seats on the plane's floor show the way to emergency exits in the event of an emergency.
Guide U light strips installed as exit route markers in aircraft.
They have been producing this patented system internally since November 2021 in Hamburg.
3D printed nozzles as consumables in production
To produce these outbound route markers, the Lufthansa Technik team used production tools produced by 3D printing. After testing different methods, stereolithography (SLA) 3D printing was chosen to make the nozzles.
Nozzle, made of Clear Resin, with integrated thread (right, still as printed with support structures).
A special request was to treat this nozzle as a consumable. A 3D printed nozzle is a cost-effective alternative to a production tool that would otherwise be produced by a conventional process such as machining or plastic injection molding. The nozzle is manufactured by SLA 3D printing using Clear Resin, which meets the necessary quality and accuracy requirements for the tool. This solution enables Lufthansa Technik to replace the nozzle on a daily basis for an optimal production process.
"If you want precise geometries, especially in the plastics sector, and you want them fast, always use 3D printing."
Ulrich Zart
Production nozzles at Lufthansa Technik made of Clear Resin on Form 3L.
Flexible optimization of the production process using 3D printing
Zart and his team saved a huge amount of time and money in their production process by printing this small part in-house. Compared to conventional methods for the production of tools of this type, they also managed to avoid high minimum order quantities and remained significantly more flexible in process optimization.
"Theoretically, we could also injection-mold our parts. But we would never be as flexible in the shape and customization of the nozzle. That's where I see a big advantage of 3D printing," explains Zart.
Also, compared to FDM 3D printing, SLA 3D printing proved to be a high-quality solution for this application.
3D printed tools for production as an alternative to traditional methods
Many companies manufacture their tools for plastic and metal manufacturing processes using plastic injection molding, CNC machining, or other traditional processes, which are often outsourced and thus accept long lead times, excessive costs, and high minimum quantities.
Depending on the application and its requirements, these processes can be replaced by 3D printed tools. The nozzle in the production of the Guide U marker for outbound routes at Lufthansa Technik is an example of a cheaper and more flexible alternative enabled by SLA 3D printing.
"One application that many people may not yet see in the future of 3D printing is using 3D printed tools as consumables in manufacturing, as we do."
Ulrich Zart