Processes to produce short-cut microfibers

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) routing said heated multicomponent fiber slurry to a fiber opening zone with sufficient mixing to remove a portion of said water dispersible sulfopolyester to produce an opened microfiber slurry with a temperature in the range of about 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;
• wherein said fiber opening zone comprises a pipe reactor;
• (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.