Patent ID: 7214335

Claim:
A method of preparing cellulose fiber, comprising the steps of: (A) dissolving 0.01 to 3% by weight of cellulose powder in the liquid-state in a concentrated N-methylmorpholine-N-oxide (NMMO) solution to provide a cellulose-containing NMMO solution containing 0.01 to 3 wt % cellulose with respect to the total weight of the cellulose-containing NMMO solution, wherein the concentrated NMMO solution contains 10 to 18 wt % water with respect to the NMMO solution; (B) feeding the cellulose-containing NMMO solution and additional cellulose powder into an extruder having a screw where the cellulose-containing NMMO solution and additional cellulose powder are subjected to dispersing, mixing, shearing, kneading, melting and measuring processes in the extruder so as to produce cellulose solution that is swollen and homogenized; (C) spinning the cellulose solution through nozzle of a spinner, solidifying it through an aeration layer and solidifying bath to obtain multi-filament; and (D) washing, drying, oil-treating and winding the obtained multi-filament.