Patent ID: 8906200
Filing Date: 2014-12-09
Classification: B01D,C08G,D21H

Abstract:
1. A process for producing a microfiber product 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 40° C. or less; (B) contacting said cut multicomponent fiber slurry with a heated aqueous stream in a mix zone to produce a heated multicomponent fiber slurry; (C) mixing said heated multicomponent fiber slurry in a fiber opening zone for a sufficient time to remove a portion of said water dispersible sulfopolyester to produce an opened microfiber slurry with a temperature in the range of about 55° C. to about 100° C.; wherein the weight % of solids in said opened microfiber slurry ranges from 0.1 weight % to about 20 weight %; wherein said water non-dispersible polymer microfiber has a minimum transverse dimension of less than 10 microns; and wherein at least about 50 weight % of said water non-dispersible polymer microfiber is suspended in said 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; and (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.