Designing Bio-based Materials for Lightweight Aircraft Seating and Engineering them to meet the Functionality Requirements

Abstract

Airbus Cabin Vision 2035 aims to transform the future experience of air travel with a focus on sustainability through its three pillars: Transparency, Decarbonization, and Circularity (Airbus, Airspace Cabin Vision 2035+). As part of this initiative, the current thesis explores the potential of bio-based materials to replace conventional fossil-based thermoplastics in aircraft seating trims. By investigating whether nature can provide lighter and more environmentally friendly alternatives, this study seeks to reduce the aviation industry's carbon footprint (during the usage phase of aircraft) while enhancing the circularity of the materials.

This research is structured in a three-phase iterative framework. The initial phase involves problem analysis and the development of design specifications. The next phase, material exploration, identifies a list of potential bio-based materials suitable for design exploration, followed by a literature review to understand their flammability and moisture resistance properties, which are critical for compliance with the rigorous standards of aircraft applications.

From the material exploration, a family of hardwood, natural fibers, and mycelium emerged as potential materials for further design exploration. Lightweighting method was employed to optimize their geometry and meet the required mechanical strength established in the design specifications (Load bearing strength up to 100kgs). This method led to the development of a more practical option: the Designing of Composites. Static load-bearing capacity calculations were conducted to assess the feasibility of the composite design with the variations in facesheet materials. The pretreated Baxis Sinica wood panel with a mycelium core emerged as a feasible solution, primarily due to its weight-to-strength ratio, ability to meet the functional requirements of aircraft, and its circularity.

In the pursuit of material optimization, studies were undertaken in exploring bio-based coatings, to enhance the flammability and moisture resistance properties ensuring its suitability for the stringent requirements of aircraft applications. With established research on enhancing the flammability and water resistance of wood-based composites, the focus was to improving the properties of mycelium. Initial post-treatment methods using inorganic flame retardants like sodium silicate effectively demonstrated flame-extinguishing properties; however, further research is required to further enhance the material's water resistance. Additionally, there is promising potential for utilizing bio-based coatings to simultaneously improve both the flame retardancy and moisture resistance of mycelium. As it is well-established that bio-derived materials can degrade over time, it is crucial to develop strategies and treatments to ensure this does not compromise the product's lifespan. Current efforts also focuses on understanding the long-term behavior of these materials and their coatings under extreme conditions. However, as these materials have not yet reached full maturity, further optimization and enhancement remain within the scope of future research.

Positioned within the framework of Circular R-strategies, this study proposes an ambitious design, utilizing a wood and mycelium to develop a composite, with textile serving as the adhesive layer. The proposed design not only eliminates the need for fossil-based materials but also reduces weight by up to 50% compared to conventional thermoplastics in seat trims. This weight reduction is significant, as even a single kilogram less can lead to a decrease of 5,000 to 15,000 kg CO2 emissions over the aircraft's lifetime.