Patent ID: 9598802
Date: 2017-03-21
CPC Classifications: C08J,D04H,D21H,Y02W

Claim:
1. A process for recovering a primary polymer concentrate stream, said process comprising: (A) contacting cut multicomponent fibers having a length of less than 25 millimeters with a treated aqueous stream in a fiber slurry zone to produce a cut multicomponent fiber slurry; wherein said cut multicomponent fibers comprise at least one water dispersible sulfopolyester and at least one water non-dispersible synthetic polymer immiscible with said water dispersible sulfopolyester; and wherein said treated aqueous stream is at a temperature of less than 40° C.; (B) contacting said cut multicomponent fiber slurry with a heated aqueous stream in a mix zone to produce a heated multicomponent fiber slurry; (C) routing said heated multicomponent fiber slurry to a fiber opening zone to remove a portion of said water dispersible sulfopolyester to produce an opened microfiber slurry; (D) routing said opened microfiber slurry to a primary solid liquid separation zone to produce said microfiber product stream and a first mother liquor stream; wherein said first mother liquor stream comprises water and said water dispersible sulfopolyester; (E) routing at least a portion of said first mother liquor stream to a second solid liquid separation zone to produce a secondary wet cake stream and a second mother liquor stream; wherein said second mother liquor stream comprises water and water dispersible sulfopolyester; and wherein said secondary wet cake stream comprises microfiber; and (F) routing said second mother liquor stream to a primary concentration zone to remove water from said second mother liquor stream to produce said primary polymer concentrate stream; wherein said primary concentration zone comprises at least one ultrafiltration membrane.