BBG GROUP
Wing Core for UAVs
Ultralight Wing Core for UAVs: From Prototype to Scalable Production
A core made from thermoplastic microspheres can significantly reduce the weight of UAV wing structures. We have already manufactured initial prototypes and delivered them to a drone manufacturer. We are now further developing the production process with the aim of achieving reproducible, largely automated and scalable production.
Lower weight creates new possibilities
Weight is a key factor for unmanned aerial vehicles. Every reduction in structural weight can create additional potential for greater range, longer flight times or increased payload. This applies to civilian applications as well as to UAV systems used in the defense sector.
Against this background, BBG is working with a particularly lightweight core material for wing structures. It is based on thermoplastic microspheres that make it possible to produce a core with a very low density of approximately 0.02 g/cm³. Compared with conventional core materials, weight savings of up to 60 percent are possible.
Our development work focuses on how this material can be processed reliably and integrated into an industrially viable production process.
Combining expanded and expandable microspheres
To manufacture the wing core, we use a mixture of already expanded and still expandable thermoplastic microspheres. The two components are mixed at a weight ratio of 1:1.
The material mixture is introduced into a preheated, open mold. Once the mold is closed, the material is brought to the required process temperature. The expandable microspheres increase in volume, fill the remaining spaces and bond with the already expanded particles to form a continuous, dimensionally stable core structure.
The main challenge lies less in the material itself than in controlling the processing conditions. Mixing ratio, material quantity and material input, temperature control and mold design must be precisely coordinated in order to produce the core reliably with the required properties.
From material trials to a functional wing core
We have now implemented the basic manufacturing process. At our Mindelheim site, we operate a manual pilot production process and have already manufactured initial wing cores and delivered them to a UAV manufacturer.
Further processing into a fiber-reinforced composite structure has also been successfully tested. We deliberately do not consider production of the core as an isolated process step. For us, the complete process chain through to the finished component is decisive.
One of the key development objectives is therefore to process and laminate the core with as few additional steps as possible. This allows the benefits of the extremely lightweight core material to be combined with efficient production of the complete wing structure.
Next step: automating production
The current development focus is on transferring the manual pilot production process into a more highly automated process.
Particular attention is being paid to automated mixing, dosing and introduction of the microspheres into the mold cavity. This is intended to reduce operator influence while further improving reproducibility and process stability.
We are also including the subsequent production steps in the process development. Our objective is a largely continuous production process in which manufacture of the core and further processing into the fiber-reinforced composite structure are efficiently coordinated.
In doing so, we combine our many years of experience in tool and mold making, machine and system engineering and automation with the development of the manufacturing process itself.
Our goal: reproducible and scalable production
The prototypes produced so far have demonstrated the basic feasibility of the process. The next development step is to turn the successful pilot production process into a manufacturing process that can deliver reproducible quality at higher production volumes.
This scalability is particularly important for UAV applications. New applications are emerging in both civilian and dual-use markets. As production volumes increase, so do the requirements for process reliability, reproducible component properties and cost-efficient manufacturing.
This is exactly where we focus our development work: we are further developing the tooling, manufacturing process and automation so that an innovative lightweight material can become the basis for an industrially viable production process.
Potential for further lightweight applications
The UAV wing core is our specific starting application. At the same time, we are investigating other components for which the combination of very low density and mold-based processing could offer potential.
Possible applications include protective helmets as well as products in the sports and leisure sector. However, these possibilities are currently not the focus of our development work. Our first priority is the further development and scaling of the process for the UAV wing core.