US 12,188,157 B2
Process for wet spinning of cellulose fibers from an alkaline spin bath
Bengt Hagström, Gothenburg (SE); Tobias Köhnke, Svanesund (SE); and Jonas Engström, Nödinge (SE)
Assigned to TREETOTEXTILE AB, Bjarred (SE)
Appl. No. 17/428,687
Filed by TREETOTEXTILE AB, Bjärred (SE)
PCT Filed Feb. 20, 2020, PCT No. PCT/SE2020/050198
§ 371(c)(1), (2) Date Aug. 5, 2021,
PCT Pub. No. WO2020/171767, PCT Pub. Date Aug. 27, 2020.
Claims priority of application No. 1950223-6 (SE), filed on Feb. 21, 2019.
Prior Publication US 2022/0112628 A1, Apr. 14, 2022
Int. Cl. D01D 5/06 (2006.01); D01D 5/22 (2006.01); D01D 10/06 (2006.01); D01F 1/10 (2006.01); D01F 2/24 (2006.01)
CPC D01D 5/06 (2013.01) [D01D 5/22 (2013.01); D01D 10/06 (2013.01); D01F 1/10 (2013.01); D01F 2/24 (2013.01)] 36 Claims
OG exemplary drawing
 
1. A process for forming a fiber tow, said process involving a wet spinning procedure comprising the steps of:
dissolving cellulose pulp in an alkaline aqueous solvent to form a cellulose spin dope composition;
spinning the cellulose spin dope composition in a coagulation bath having a pH of more than 7.0, to produce a fiber tow; and
passing the produced fiber tow through a sequence of consecutive stretching and washing steps in which the fiber tow is washed with washing liquid having gradually lower alkalinity.