A project of Saab where Large Scale Additive Manufacturing was chosen for printing a mold as part of the Clean Sky 2.

Through the collaborative work with Ai Build and Airtech, Saab completed a project in 2022 that involved large scale additive manufacturing for creating a mold as part of the Clean Sky 2 initiative. The project discussions were initiated in the summer of 2021, and required preliminary research to set things in motion.

The project faced several unique challenges, one is that the design had no regular polymer printing size, meaning that the part could not be printed by any mid- or industrial-scale machines. As a result, large area/scale additive manufacturing (LAAM/LSAM) was the only viable option for producing this particular component.  In the recent years, LSAM has been utilized for manufacturing of various functional parts thanks to the developments in the use of novel materials, software programmes, and printing processes. We have seen various examples of the additively manufactured large parts that can be employed as boat hulls, sailing yacht parts, functional tools, prototypes for metals, and finally as molds.

Another important requirement that needed to be addressed during this project was the material of choice for printing the mold. This tooling application involved high-temperature endurance without any leakages. While fused filament fabrication (FFF) and fused deposition modeling (FDM) offer numerous high-performance materials, LSAM-compatible materials are only available from a few suppliers. In the end, the component, which is a cargo door mold as shown in the picture, was printed using a high-performance polymer composite, Dahltram I-350CF [1] (modified polyetherimide with carbon fiber), at Airtech’s facility in Luxembourg with the help of Ai Build’s parameter optimization process. The additively manufactured mold which has dimensions exceeding 2 meters, was produced using Autonomous Large Scale 3D printing technology and post-processed to obtain a surface roughness of Ra = 0,8 µm.

Figure 1: Side part of the large area printed and milled tool with fixtures.

Along with the adaption of emerging technologies and materials, additive manufacturing of polymers with the help of LSAM provides numerous benefits, such as reduced weight and cost compared to metal tools. The combination of freedom of design provided by AM processes as well as the utilization of durable and re-usable high-performance materials hold promises for future applications. Jakob Ring, Project Manager for Clean Sky 2 and Head of R&T at Saab Aerospace Systems said “We are really looking forward to exploring the benefits of Additive manufacturing. Both for tooling applications, as in this specific case, and also for parts manufacturing. When designed appropriately we hope that we can significantly reduce lead time and manufacturing cost for low rate or complex applications. Next step with this tool is to manufacture a composite cargo door aimed for the Clean Sky 2 Multifunctional Fuselage Demonstrator (MFFD).” In addition to this, the ability to print such large parts on demand presents a sustainable solution for industries seeking eco-friendly alternatives.

Please note that this project has received funding from the Clean Sky 2[2] Joint Undertaking under the European Union’s Horizon 2020 research and innovation program under grant agreement No. 945583 GAM-2020-LPA.

Contact: Merve Canalp, Head of Research, merve.canalp@amexci.com

[1] https://airtech3d.com/dahltram-tooling-resins.

[2] https://www.clean-aviation.eu/clean-sky-2/programme-overview-and-structure.