Material Portrait: Expand Fibre

In the first instance of the research, our team set out to scope the existing state of the art when it comes to biomaterials. The review showed a range of materials that demonstrate various levels of availability to market: now, near, or far. It also showed the different parts of the supply chain in which innovation could take place. The review of over 80 different materials led to creating a lifecycle map that highlights the stages of resource extraction, transformation and use of the materials, with a focus on materials from non-fossil sources. This map is based on the materials from the sample collection and built as a collaboration between the HEREWEAR partners who are involved in design and material processing. To further validate and explore the impact of designing with biomaterials across the lifecycle, we have interviewed some key materials innovators using the map as the starting point to better understand their material. There are many different types of bio-based materials that offer complementary angles on a circular future. Understanding what to look out for to reduce impacts and how to use exemplary materials adequately in well-designed products is key to the success of a circular bioeconomy.

This series of posts presents these materials and highlights how they show paths towards circular local and biobased systems that we can learn from and follow in HEREWEAR.

Expand Fibre is a collaborative R&D programme and ecosystem founded by Finnish companies Fortum and Metsä Group which aims to accelerate the development of new sustainable bioproducts. One of its major aims is to replace fossil-based feedstock with biomass for textile fibres.

The materials developed as part of the project are a remarkable example of innovation in the field and support some of the key points also put forward in the HEREWEAR project. The Expand Fibre project is vast in its range and ambitions, here we focus on the two materials that are being developed by Fortum and Metsä and describe how they contribute to the bio-based textile landscape.

Fortum has been developing feedstock processing for fibres made from straw (1). The crux of the innovation is in making the waste straw suitable for further processing into the fibre, which can then be done in various ways. In the HEREWEAR material lifecycle map, this phase is defined as fractionation. The Fortum team develops organosolv cooking technology with Finnish company Chempolis for this biorefining process (2). During fractionation, the three lignocellulosic components cellulose, hemicellulose and lignin are separated as pure components. The cellulose fraction is then processed to meet the expectations of the consecutive process, for example, textile fibre production. Fortum made its first straw-based garment launched in co-operation with Spinnova, whose spinning process is entirely mechanical, pressing the pulp through spinnerets like a spider (3). The Fortum straw pulp can also be used in other processes such as carbamate technology that chemically dissolves the cellulose to spin fibre. For instance, to produce the Infinna™ staple fibres, by Infinited Fibre Company using the carbamate technology, a wet-spinning process is used (3bis). These fibres have been used in a collection of luxury streetwear garments designed by Finnish fashion designer Rolf Ekroth and introduced at Pitti Uomo in March 2021. Whether using the Spinova or the Infinna or other sustainable MMCF technology to create fibre from straw, these fibres can then be blended with a range of other fibres, taking into account the sustainability and end of life parameters, to support the performance and cost of the straw fibre. For recycling, in the case of Spinova, the mechanical process (4) can be repeated to turn the end of life products into new fibres. In the carbamate process, the dissolution could be applied to waste products to recover and re-spin the cellulose (5). In both cases, the assumption is that the materials can be fully biodegradable as pure cellulosic fabrics (6).

The part of the material innovation work carried out by Metsä focuses on another abundant biomass stream: wood pulp (1). Metsä already produces a range of wood-based products and build on this expertise. The company works with Canopy, an organization dedicated to forest conservation, to ensure that the wood is sourced in the most sustainable way. Current processes to produce fibres from forestry require dissolving grade pulp which has been treated to remove all but the cellulose content. The new textile fibre made by Metsä in partnership with Itochu is called Kuura. It is made from paper grade wet wood pulp which still has some hemicellulose in it (2). The efforts have been concentrated on streamlining the process, with most operations taking place in the Metsä bioproduct factory using as few and as safe chemicals as possible. The pulp is transformed into staple fibres by Metsä using an ionic liquid process (3), and the Japan-based partner Itochu focuses on the value chain starting from the production of yarns(4). The fabric construction and finishing processes are carried out by Itochu and its brands’ partners (5). Some tests and discussions are underway to explore fibre blending with recycled polyester for example, in order to support the qualities of both materials. Kuura has been used in a garment collection by Reracs at Japan Fashion Week in March 2021. Here also the possibilities for the end of life are with dissolution through a repeat of the ionic liquid process, or biodegradation depending on the environment. Mechanical recycling, treating the material like other cellulosic fibre such as cotton or viscose, may also be an option.

Both processes are an example of ways in which locally abundant biomass, straw or wood pulp, can be harnessed in optimized processes to achieve textile materials with reduced impacts. The circularity of the material, as often, will depend on the types of blends and products in which it is included and the recovery system in place. These materials are in the pilot development phase and not yet commercially available.