Periodic Reporting for period 2 - ECO-CLIP (Eco-friendly Frame Clips and System Brackets for a fuselage demonstrator)
Periodo di rendicontazione: 2021-08-01 al 2022-10-31
Recycling materials is one of the main objectives in all industries, including aeronautics since the footprint of air travel also extends across the entire lifecycle of the aircraft, hence airliner's components must be preferably recyclable. ECO-CLIP is focused on the recycling of light materials to reduce weight in the construction of aircraft by replacing metal parts with composite structures. Thermoplastic Composites have a great recycling potential, which can be translated in cost-reduction.
ECO-CLIP project has contributed to the CS2 objectives with an in-depth study of the behavior of new CF/LMPAEK recycled composites with the definition of a manufacturing process and the validation of the proposed methodology from an environmental and economical point of view. Therefore, ECOCLIP has developed a recycling process able to convert long carbon fiber LMPAEK composite from factory waste into short fiber reinforced compounds. Manufacturing of structural parts as frame clips and system brackets has been evaluated through injection moulding and 3D printing and has been installed in a fuselage demonstrator. ECO-CLIP has employed ultrasonic welding as a joining process to connect the clips to the rest of the structure avoiding the use of fasteners and rivets.
As a result, it has been demonstrated that almost 100% of the scrap can be re-use reducing parts weight that lead to a 60% carbon footprint, and 45% cost reduction. ECO-CLIP has actively contributed to one of the great objectives of CS2 Large Passenger Aircraft (LPA) Platform using advanced materials such as recycled CF/LMPAEK thermoplastic composites for the lower half of a multi-functional fuselage demonstrator (MFFD), within the reduction in weight of the fuselage.
ECO-CLIP project has contributed to the CS2 objectives with an in-depth study of the behavior of new CF/LMPAEK recycled composites with the definition of a manufacturing process and the validation of the proposed methodology from an environmental and economical point of view. Therefore, ECOCLIP has developed a recycling process able to convert long carbon fiber LMPAEK composite from factory waste into short fiber reinforced compounds. Manufacturing of structural parts as frame clips and system brackets has been evaluated through injection moulding and 3D printing and has been installed in a fuselage demonstrator. ECO-CLIP has employed ultrasonic welding as a joining process to connect the clips to the rest of the structure avoiding the use of fasteners and rivets.
As a result, it has been demonstrated that almost 100% of the scrap can be re-use reducing parts weight that lead to a 60% carbon footprint, and 45% cost reduction. ECO-CLIP has actively contributed to one of the great objectives of CS2 Large Passenger Aircraft (LPA) Platform using advanced materials such as recycled CF/LMPAEK thermoplastic composites for the lower half of a multi-functional fuselage demonstrator (MFFD), within the reduction in weight of the fuselage.
ECOCLIP main objective has been the development of new recycled material from LMPAEK material reinforced with continuous carbon fiber. For this purpose, different formats of scrap material have been taken, crushed and screened. Subsequently, the shredded material was separated into 3 fractions, the smallest ones for 3D printing, the next ones for injection moulding and the last ones for reprocessing. During the project, the reprocessing study was carried out, crushing the larger particles, and dividing them again achieving a cycle efficiency of 97%. Once the recycling cycle was studied at a laboratory scale, the rout was taken to industrial level, using UNTHA cutting mills for processing and avoiding screening. Subsequently, this shredded material was blended to have different fractions of carbon fiber. They were studied rheologically, mechanical and thermal properties. This information was introduced in an injection simulation program to know which of the materials would be optimal for ECOCLIP parts. As a result, the 40%CF blend was selected as optimum, since some of the larger and more complex geometries could not be filled with higher amounts of fiber.
In parallel to this material selection, modifications were made to the parts to ensure injection and printing. The necessary moulds were created and used to produce frame clips (400) and system brackets (46) once all the injection parameters were defined. To validate 3D printing as a new technology to manufacture aeronautic parts, the same material was used in direct printing of pellets, achieving high fiber percentages in the final part and a better dimensional accuracy than injection. Both processes, were validated through standard specimens both mechanically and thermally.
Transversally to these, texturing was developed for the EDs. This texturizing favours the bonding between the clips and the MFFD by means of ultrasonic welding. Different geometries were studied and textured on metal inserts that were then introduced into the injection mould to replicate them. Sigle lap shear tests were performed, proving that the ridgets geometry was optimal. Once the texture was selected, inserts were made for the final clip mould resulting in a part ready for installation in a single injection step. To test the bonding, corner bending test was modified for which LMPAEK continuous fiber laminates were welded to the clip. This was used to check that the required strength was achieved.
During the project, both economic and environmental information was collected, which made it possible to realize the economic and environmental cycle of recycling. In this way two scenarios cradle-to-door and cradle-to-grave were analysed. The cradle-to-grave results indicate an improvement in economic and environmental performance thanks to the reduction of fuel consumption by lightening the weight of the parts. Therefore, it was possible to develop a new injectable material to manufacture aeronautical parts, which can also be welded leading to an improvement with respect to the current situation.
Regarding dissemination and communication, the results of the project have been presented on workshops, congresses , and exhibitions. These results include the work performed by recycling carbon fiber reinforced thermoplastics, injection moulding, 3D printing, and ultrasonic welding, among others.
In parallel to this material selection, modifications were made to the parts to ensure injection and printing. The necessary moulds were created and used to produce frame clips (400) and system brackets (46) once all the injection parameters were defined. To validate 3D printing as a new technology to manufacture aeronautic parts, the same material was used in direct printing of pellets, achieving high fiber percentages in the final part and a better dimensional accuracy than injection. Both processes, were validated through standard specimens both mechanically and thermally.
Transversally to these, texturing was developed for the EDs. This texturizing favours the bonding between the clips and the MFFD by means of ultrasonic welding. Different geometries were studied and textured on metal inserts that were then introduced into the injection mould to replicate them. Sigle lap shear tests were performed, proving that the ridgets geometry was optimal. Once the texture was selected, inserts were made for the final clip mould resulting in a part ready for installation in a single injection step. To test the bonding, corner bending test was modified for which LMPAEK continuous fiber laminates were welded to the clip. This was used to check that the required strength was achieved.
During the project, both economic and environmental information was collected, which made it possible to realize the economic and environmental cycle of recycling. In this way two scenarios cradle-to-door and cradle-to-grave were analysed. The cradle-to-grave results indicate an improvement in economic and environmental performance thanks to the reduction of fuel consumption by lightening the weight of the parts. Therefore, it was possible to develop a new injectable material to manufacture aeronautical parts, which can also be welded leading to an improvement with respect to the current situation.
Regarding dissemination and communication, the results of the project have been presented on workshops, congresses , and exhibitions. These results include the work performed by recycling carbon fiber reinforced thermoplastics, injection moulding, 3D printing, and ultrasonic welding, among others.
A novel composite based on recycled short fibre CF/LMPAEK had been developed for the first time and validated for each of the selected manufacturing methods. As a result, it was conquering a 100% re-use of the scraped. This had been the first time using recycled CF/LMPAEK in the development of new composites for injection moulding and FGF as 3D printing method.
Recycled short fibre CF/LMPAEK pellets had been developed and 3d printing parameters and injection moulding optimization was archived. Finally, to evaluate environmental benefits of used recycled materials for injected parts or 3d printing, LCA and LCC had been carried out in comparison with virgin material. That had been the reference studied to further scale-up of the technology.
Ultrasonic welding had been validated as the most suitable method for joining recycled CF/LMPAEK short fibre composites to UD CF/LMPAEK structural laminate and a welding window was set to weld the clip to the skin and frame couplings. In this sense, during the project the dissimilar ultrasonic welding between short CF and laminates was validated as first time. ECOCLIP project has ensured a strong strategic impact and has cleared socio- economic benefits within the next five to ten years by contributing to Enhance European aeronautic industry competitiveness and employment, to improvement of the quality of life using a new process with clearly health and environmental benefits and increasing the customer satisfaction contributing to more sustainable development. Also, an improvement of the Health and Safety, Environment and Working Conditions and Increase the Employment and levels of skills.
Recycled short fibre CF/LMPAEK pellets had been developed and 3d printing parameters and injection moulding optimization was archived. Finally, to evaluate environmental benefits of used recycled materials for injected parts or 3d printing, LCA and LCC had been carried out in comparison with virgin material. That had been the reference studied to further scale-up of the technology.
Ultrasonic welding had been validated as the most suitable method for joining recycled CF/LMPAEK short fibre composites to UD CF/LMPAEK structural laminate and a welding window was set to weld the clip to the skin and frame couplings. In this sense, during the project the dissimilar ultrasonic welding between short CF and laminates was validated as first time. ECOCLIP project has ensured a strong strategic impact and has cleared socio- economic benefits within the next five to ten years by contributing to Enhance European aeronautic industry competitiveness and employment, to improvement of the quality of life using a new process with clearly health and environmental benefits and increasing the customer satisfaction contributing to more sustainable development. Also, an improvement of the Health and Safety, Environment and Working Conditions and Increase the Employment and levels of skills.