Making wood the new star of fashion catwalks

If you take an inventory of your closet, chances are you’ll have several garments made at least partly of polyester and nylon. These two low-cost textiles are staples of fast-fashion and currently make up about 60% of clothing and 70% of household textiles.

Polyester and nylon are synthetic fossil-based fibres, meaning they are derived from oil and natural gas. The production of these fibres, their dominant position in the fashion industry, and the fact that they are not biodegradable, means that they have a huge impact on our environment. They also contain harmful microplastics that make their way into every conceivable corner of our land, oceans and waterways.

As a natural fibre, cotton is more easily recycled and requires fewer fossil fuels for its production compared to nylon, for example. However, the cotton industry demands mass land areas for cultivation; worldwide, cotton crops are sprayed with the most chemicals; and, finally, growing cotton requires vast amounts of water.

Where does this leave us?

Fewer toxic chemicals in ‘natural’ textile production, please

Bio-based textiles are emerging as a solution. There is a wealth of innovation in this area, with new – and old – technologies turning waste and residues of other industries into sustainable, biodegradable materials that are kinder on our planet.

Viscose and lyocell (cheaper, more durable alternatives to silk) are both produced from wood and touted as more sustainable alternatives to natural cotton and synthetic polyester. They are man-made, semi-synthetic fibres: while they have a natural base and require much less land cultivation and water than cotton, heavy processing and solvents are needed to turn them into wearable textiles.

Stina Grönqvist, research team leader at the VTT Technical Research Centre of Finland Ltd, is a specialist in bio-based materials, and she is not impressed by today’s viscose and lyocell production methods. ‘At the moment, the raw material base is limited, the solvents used, and required chemicals are not safe or environmentally friendly, and the production value chain, especially finishing treatments of the textile fibres, causes extensive freshwater pollution.’

For example, in the production of viscose, the wood pulp is treated with chemicals, a solvent is applied, and the resulting wood-pulp is spun into a fine thread. This highly polluting process releases many toxic chemicals into the air and waterways surrounding production plants.

Production of lyocell is similar, but uses a direct solvent, N-methylmorpholine N-oxide (NMMO), that does not require the chemical modification step needed for viscose. While lyocell production is considered less harmful on the environment than viscose, NMMO is explosive and highly unstable, limiting its applicability.

The CBE JU-funded GRETE project, coordinated by VTT, is developing new non-toxic and recyclable solvents that will boost the safety and sustainability of making textiles from wood. This new technology will remove many of the current risks to both human health and the environment embedded in current manufacturing processes, and also open the door for producing high-quality textile fibres from a much broader range of sustainable raw materials like paper grade pulp, recycled paper and textiles.

‘The use of paper grade pulp instead of dissolving pulp would be an environmental and economic benefit because it is a less processed raw material,’ explained Grönqvist. The project is also developing fibres with completely new properties that can reduce the amount of water used in the production cycle.