Abstract

La fabricación avanzada en materiales compuestos termoplásticos es clave para satisfacer los requerimientos del sector aeronáutico. Las ventajas diferenciadoras de los polímeros termoplásticos de alto rendimiento frente a las resinas termoestables, hace que estos materiales sean cada vez más demandados en el sector. Es clave su capacidad de reprocesado que permite 1) la automatización de los procesos, 2) la utilización de la tecnología de unión por soldadura entre sus componentes y 3) aplicar criterios de reciclabilidad y reutilización, imposibles para los materiales termoestables. Su mayor tenacidad y su cumplimiento de los estándares más estrictos de llama, humo y toxicidad aportan un plus importante a sus prestaciones. Polieterimida (PEI), Sulfuro de Polifenileno (PPS), Polieteretercetona (PEEK), Polietercetonacetona (PEKK) y el novedoso poliariletercetona (PAEK) son las matrices empleadas en esta tecnología de materiales compuestos termoplásticos de altas prestaciones. En función de la tipología del componente final, se selecciona la tecnología de procesado más adecuada, dependiendo de aspectos como geometría de pieza, tamaño y número de piezas a fabricar. El objetivo del presente trabajo fue la exploración de tecnologías de procesado de composites termoplásticos, tales como: Termoconformado de láminas compuestas (organosheet), obtención de laminados customizados (tailored sheet consolidation) y moldeo de escamas y/o pellets reforzados mediante compresión (T-BMC, Thermoplastic Bulk Moulding Compound) a través del desarrollo y puesta a punto de la fabricación de prototipos. Los resultados demostraron que estas tecnologías cumplen los requerimientos exigidos por el sector aeronáutico tanto en procesabilidad como en propiedades.

Abstract

Within the European platform Europe's Rail, whose objective is to promote research and development activities in the railway sector, can be found the PIVOT-2 project (Grant Agreement no. 881807), which addresses the implementation on track of light and environmentally friendly vehicles, reducing energy consumption and therefore the CO2 emissions derived from the transport sector.

To meet these objectives, the project seeks to achieve the weight reduction of primary structures. This way, the use of composites materials appears as an interesting alternative in a sector where their use has been very limited to non-structural components, largely due to the need to comply with fire protection regulations (EN 45545) [1]. Thanks to the development of new resins, the possibilities of these materials are increasing, being necessary to evaluate their performance in new applications.

Similarly, the characteristics of the railway industry mean that the manufacturing processes of composite materials widely used in other sectors, such as the aerospace, must be adapted. Likewise, and due to the requirements of the final product, it will be necessary to adapt the materials to these new applications, developing materials with higher grammage or ply thickness than those currently used.

The project evaluates the automatic laying of different materials developed for the railway sector. The behaviour of flat laminates is analysed, as well as the lamination of the material on core structures. Finally, studies are validated with the manufacturing of a train carbody section, using automatic lamination processes (ATL). 

Abstract

Industrial automated tape layup methods significantly increase the productivity, precision, and efficiency of manufacturing methods for large aerospace parts; however, although they allow reducing scrap fraction compared with manual processes, it keeps being too high, requiring waste management. The scope of the MC4 project, part of Horizon Europe program, is to not only recycle that scrap material, but also to transform it to a completely new, functional part, without the need of adding additional material other than this recycled scrap. This can be achieved by cutting that material into strip shape and reducing it to a specific thickness by means of a compacting process. Those homogenous thickness strips can then be processed using a heated plate press to form it to any needed shape. Mechanical properties will be studied and compared to the original material, to check if this process is suitable for the manufacturing of functional parts. As this method does not separate the original resin and fiber, it avoids the usage of chemicals that can damage the properties of the material and increase the risk and pollution of the process, which is ideal for a recycling process.