LONDON – A new report has updated on pioneering work to chemically separate cotton and polyester fibres so that both fibres can be reused to make new high quality textiles. The report describes how new fibres – namely viscose filaments – can be produced from separated and recycled cotton fibres. In an update on previous work, it was found that the produced viscose filaments had the same strength as filaments obtained from regular dissolving pulp used for textile fibres, “which is crucial for further industrial processing towards recycled fabrics.”
As we reported at the start of this year, Mistra Future Fashion in Sweden has successfully recycled worn sheets made of a blend of polyester and cotton to produce two new product streams – cotton pulp, which is suitable for regeneration into cellulosic textile fibres (such as viscose fibres) and polyester monomers which can be re-polymerised into polyester.
The project – Blend Re:wind – focused on the chemical recycling of poly-cotton fibre blends and aimed to separate and generate a new feedstock for future industrial use, namely polyester monomers and cotton pulp which is suitable for regeneration into cellulosic textile fibres.
The update on the work includes an environmental assessment of the Blend Re:wind process in order to identify the future environmental potential of the process. However, the report notes: “It is important to keep in mind that the environmental assessment was made with data obtained from smaller pilot or bench scale conditions and energy and chemical demands has therefore not yet been optimised. Despite this, the environmental assessment can be used as a guiding tool in the further development of the Blend Re:wind process.
A key benefit with the Blend Re:wind process is that the separation takes existing industries into consideration as the separation process uses chemicals already utilised in the Swedish forest industry, and in the viscose industry, which will be easy future integration.
Hanna de la Motte, theme leader for theme 4, Recycling, within Mistra Future Fashion and research scientist at RISE says: “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 minimise both environmental and economic costs, while boosting businesses. 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.”