CoCoNut is an EU-funded R&D Project which focuses on the production of a composite aerostructure demonstrator part with internal cavity of complex geometry, using a water-soluble core to create the hollow configuration. The objective is to provide a potential substitute for metallic cores that is easily integrated with existing RTM tooling, able to withstand high injection pressures, rapidly removable from the finished part, and reusable / recyclable… relating to the need for a high serial production output. This technology using washable cores is compatible with production if CFRP parts via RTM, LRI and prepreg-based processes. It has been tested at IAI, and is currently used by Airbus.
Model of 360° rotating view of demonstrator part
The challenge in this project is to design and implement an innovative solution to make a complex composite-based part with a large trapped cavity for a critical aircraft structure, via a method compatible with high production rates and achieving the required geometry and properties for the part.
The proposed solution is to replace the use of multiple metallic internal tools with an internal core based on a nonmetallic water-soluble material, which can be easily removed from the finished part by washing. The core material is environmentally friendly and recyclable.
The overall objective of the CoCoNut project is to demonstrate the efficacy of a water-soluble internal core material for the fabrication of a composite aircraft landing gear part with internal cavity, meeting the design requirements, withstanding the required process conditions, and showing an advantage over the existing technology in terms of manufacturing time and cost.