Hille Rautkoski, Hannes Orelma, Tiia-Maria Tenhunen, Kari Kammiovirta, Vuokko Liukkonen, Minna Hakalahti, Ali Harlin, VTT – Technical Research Centre of Finland
Ville Klar, Aalto University
Cellulose pulp can be extruded into a continuous fibre ribbon by using a DES as a spinning medium. Deep eutectic solvents (DESs) consist of two or more components that form an eutectic solution with a lower melting point than each of the individual components. In this study the DES was composed of choline chloride (ChCl) and urea, and used as a swelling agent and rheological modifier in order to produce water-stable fibre yarns from wood pulp.
The dry-jet wet spinning was applied to prepare fiber filaments. The developed method is easily up-scalable with simultaneous spinning jets making a great amount of fibre yarn filaments possible in short time. The water resistance of the prepared filament is achieved by a short heat treatment. The method allows continuous filament production and the filament can be cut to staple fibre if required.
Characteristics of filaments
The produced filament exhibits native wood cellulose structure without losses of hemicelluloses. It is water resistant. Filament is between 60 – 120 ± 14 µm (depending on the utilized nozzle diameter). The length-mass is 170-250 dtex (depending on the utilized nozzle diameter). The filament is almost fully compostable and fully recyclable. The manufacturing costs are low.