Turning waste cotton into fibre for the fashion industry

VTT Technical Research Centre of Finland has developed a cellulose dissolution technique that can turn old, worn-out cotton clothing into new fibres for the textile industry. Now, a group of Finnish organisations has launched a project to test the new technique at all stages of the value chain.

Cellulose wet-spinning is a process by which cotton that is not suitable for re-use can be dissolved to make cellulose solution, which can be turned into new fibre. The new production technique is more environmentally friendly than the technique currently used to make viscose fibre, as no carbon disulfide is needed in the dissolution process. Compared to virgin cotton, the method also reduces the water footprint by more than 70% and the carbon footprint by 40–50%.

The technique will form the basis of the Circular Economy of Textiles (TEKI) project, which is aimed at piloting and modelling a closed-loop ecosystem in line with the principles of the circular economy. As part of the project, VTT and consultancy company Ethica have brought together a group of organisations representing different activities in the value chain. The common goal of the organisations is to promote the recycling of textiles while adding value to their business activities or creating new business.

The pilot phase of the project began in May when the Helsinki Metropolitan Area Reuse Centre collected and pre-processed cotton textiles thrown away by consumers that could not be re-used as clothing or used as material for recycled products. The material was then crushed and ground by Suez.

VTT is currently in the process of turning the material into a cellulose carbamate solution, and will be fibreising the solution at VTT’s pop-up plant in Valkeakoski in October. Pure Waste will turn the fibres into thread and the thread into knitted fabrics. These will be manufactured into a commercial clothing line by Seppälä, which will be available towards the end of 2016.

The aim is to sell the garments in recyclable RePack packaging, which means that customers will receive their products without the usual packaging waste. Furthermore, it will enable them to use the packaging to return their old textiles to the Helsinki Metropolitan Area Reuse Centre for recycling.

“This is the first time that cellulose solution made from recycled materials is being wet-spun on an industrial scale,” said VTT Senior Scientist Pirjo Heikkilä, who is responsible for coordinating the TEKI project.

Image credit: Joonas Lumpeinen.