PORTEFEUILLE

Over one third of the world’s non-renewable resources are used for mobility; natural materials are interesting due to their low environmental footprint and low density. With increasing worldwide population and food shortage, can we up-scale waste into structural and functional materials? Nature readily demonstrates high mechanical performance from relatively weak constituents by structuring across different length scales. We seek to accept Nature’s kind gesture and wish to develop industrially scalable hierarchical materials from waste by working with developing Nations. A modelling strategy and new materials shall be developed, then sustainable and ecological supply chains shall be defined with designers, engineers and industry to develop product for fashion or structural applications.

We believe the project to have impact in understanding of ecological materials, which links the value chain from third world country sourced raw materials, to high quality, functional and desirable Swiss products. Therefore, the project would be expected to launch various spin off projects to boost Swiss economy in the area of ecological textiles and their products.

We have been studying and developing our material scientifically in order to identify crucial aspects to facilitate the transfer to an industrially relevant stage. We retrieved access to the abundant raw banana material through our partners in India. The banana pseudo-stem offers a large amount of easy extractable fibres situated along its circumference. Those fibres are rather coarse and may be used to be processed into interior apparel. The pseudo-stem core, however, offers very fine fibres which can be directly spun into yarns of a low density. Both fibre types can be also processed into technical yarns via hand-, ring- and rotor-spinning techniques. With our partners in Switzerland and Germany we have already a broad selection of different yarns due to the technique used and the pre-treatment of the fibres before spinning. However, due to the characteristic length of the technical fibre along with smooth fibre surface, the spinning was initially not straightforward. The current yarn was produced on a laboratory machine, which allows for up-scaling of the process and further for the manufacturing of textiles. Knitted fabrics were produced, which can be, dependent on the structure, applied in apparel, garments, interior textiles as well as light weight parts for the automotive industry. To better understand the property-structure-relationship we also characterised the mechanical performance as well as the morphology of the elementary banana fibres. We found that the mechanical properties are similar to those of widely appreciated natural fibres such as flax and hemp. Banana is a lignocellulose material and has similarities with conventional wood such as the very low density and large space inside the tubular structure, the so-called lumen. That opens up a completely new field of applications, i.e. building industry. In this industrial sector, additive manufacturing (also called 3D printing) is becoming to play an important role, as it allows one to freely design complex three-dimensional shapes. On a small scale, we are able to 3D-print natural fibre yarns either to form free-standing geometries or to structural reinforce light weight parts. On a larger scale, thermoforming processes were developed using pre-impregnated banana fibre woven fabrics. The so-called organosheet forming process is widely appreciated in the automotive industry and is being applied for large complex shapes.

Alles Banane, in Hochparterre, 11.10.2018