Method for preparing regenerated cellulose fiber by two-step coagulating bath process

摘要

The present invention relates to a non-toxic process and system for pilot-scale production of cellulose products, and particularly to a process and system for pilot-scale production of cellulose products by using aqueous sodium hydroxide/urea solution pre-colled to lower than −8° C., in which cellulose could dissolved rapidly. The said process and system can be used to produce fibers, films, chromatographic packings, or nonwovens of regenerated cellulose, as well as to produce a variety of high added-value products by adding other materials such as functional materials, nano-materials, etc.

主权项

1. A process for pilot-scale production of cellulose products, the process comprising:
(a) pre-cooling a mixed aqueous solution of sodium hydroxide and urea to a first temperature of −15° C. to −8° C.; (b) placing the pre-cooled mixed aqueous solution at a second temperature of 0° C. to 20° C., and then adding a cellulose raw material which is thereby dissolved sufficiently under agitation to obtain a cellulose solution; (c) filtering and deaerating the cellulose solution; and (d) using a molding device for pilot-scale production to allow the filtered and deaerated cellulose solution to form a cellulose product, said molding device comprising a two-step coagulation bath spinning device comprised of a first coagulation bath and a second coagulation bath,
wherein said filtered and deaerated cellulose solution first enters said first coagulation bath for initial processing and then enters said second coagulation bath for further processing,wherein said first coagulation bath is comprised of a mixed aqueous solution of H2SO4 and Na2SO4, wherein the concentration of H2SO4 is in a range of 5 wt % to 20 wt %, the concentration of Na2SO4 is in a range of 5 wt % to 25 wt %, and the bath temperature is in a range of 10 to 15° C., andwherein said second coagulation bath is comprised of an aqueous H2SO4 solution, wherein the concentration of H2SO4 is in a range of 3 wt % to 20 wt %, and the bath temperature is in a range of 0 to 60°.