A new method developed at VTT Technical Research Center of Finland involves dissolving worn and discarded cotton and using it as a raw material for new fiber.
The first product models demonstrate that recycled fiber can be transformed into a yarn and pleasant fabric.
Based on a carbamate dissolution process, the technology has been used to produce the first batch of recycled fiber in a pilot facility.
The fabric made from the recycled fibre met the researcher's expectations: it is smooth with a subdued matt finish and drapes nicely. According to researchers Ali Harlin and Pirjo Heikkilä of VTT, it feels natural.
The method is much friendlier to the environment than the semi-synthetic viscose (rayon) process, in which carbon disulphide is needed for dissolution. In addition, polyester residues are removed from the cotton material using methods familiar from the pulp industry.
According to calculations during the technology commercialization project, the carbon footprint of recycled fiber produced using carbamate technology is about a third smaller than for cotton and in the same category and as the most environmentally friendly viscose. The water footprint of the recycled fiber is around 2% of that of virgin cotton and 10% of viscose.
Yarn was spun at Tampere University of Technology from discarded cotton turned into fiber in VTT's laboratory. The fiber's characteristics rivaled those of commercial yarns when being spun. Following this stage, the first model products, gloves and flat-knitted fabrics, were made by knitwear company Agtuvi.
R&D is still required in order to achieve process reliability. The Infinited Fiber Company startup has been established to advance the process design and licensing of the technology.
The spinning process is being developed towards industrial production through collaboration between VTT and the Infinited Fiber Company at VTT's Bioruukki pilot center. A range of cellulose fibers may be developed at a spinning unit built at Bioruukki this summer.
Towards a Closed Loop
VTT's method forms part of the TEKI project, which was launched internationally with the title of The Relooping Fashion Initiative. The project involves piloting and modeling a closed-loop ecosystem in line with circular economy principles; the ecosystem will enable new industrial applications of previously unusable textile waste.
VTT, Ethica, the Helsinki Metropolitan Area Reuse Center, Seppälä, Remeo, Pure Waste Textiles, RePack, Touchpoint and Lindström are involved in the project. The project is funded by Tekes and the participating businesses.