The process breakthrough came after six years of research in textile recycling and is an important milestone toward the future of global textile recycling systems necessary to enable circularity for fashion and textiles, said Hanna de la Motte, theme leader of Mistra Future Fashion and a research scientist at the Research Institutes of Sweden.
“Our separation process, Blend Re:wind, is developed having existing industrial processes in mind, and our aim is to integrate as much as possible to minimize both environmental and economic costs, while boosting businesses,” de la Motte said. “Scaling up from lab scale is the biggest challenge at the moment and it is also costly. The integration possibilities of the Blend Re:wind process would, however, address these challenges in feasible ways.”
Mistra Future Fashion is a research program on circular economy and serves for a future positive fashion industry.
[Read more about textile recycling: Tackling Textile Waste, From Collection to Regeneration]
She said there are various innovative recycling methods in progress globally at the moment that are “highly needed for successful future recycling systems. Different processes will most probably be needed and we hope that Blend Re:wind is one of these on the global market in the future.”
In Blend Re:wind, new viscose filaments from cotton are produced by a chemical recycling process of polyester and cotton fiber blends. The process generates three circular outgoing product streams. Cotton is turned into new high-quality viscose filaments and polyester into two pure new monomers.
Sigrid Barnekow, program director at Mistra Future, explained that the project focuses on chemical recycling of polyester and cotton fiber blends with the objective to separate and generate relevant outputs for future industrial use–polyester monomers and a cotton pulp suitable for regeneration into cellulosic textile fibers, like viscose.
The key focus is on the cotton recycling stream to produce high quality viscose filaments from the separated cotton residue, which is crucial for further industrial processing toward recycled fabrics, Barnekow noted.
So far, viscose filaments have successfully been obtained from cotton separated from worn-out polyester and cotton blend sheets. The filaments have the same quality as filaments made from commercial dissolving pulp used in existing viscose production.
The separated polyester residue known as monomers, can be re-polymerized into high quality polyester. A strong benefit with this process is that the separation takes existing industries into consideration, and the aim is integration with existing forest and chemical industries, or other recycling options. The separation uses chemicals already utilized in the Swedish forest industry, and in the viscose industry, to facilitate possible integrations.
Blend Re:wind was developed in the Swedish Mistra Future Fashion initiative by the Chalmers University of Technology, Research Institutes of Sweden and the international forest industry group Södra.
The project budget is 600,000 euros ($705,000), which has been funded in Mistra Future Fashion with funds from the Mistra Research Foundation, RISE Circle Economy Centre of Excellence, and in-kind contribution from involved partners.