The invention discloses a method for preparing superfine dyeable
polypropylene fiber by a sea-island composite
spinning method. The method comprises the following steps: (1),
copolyester additive is prepared through the method of combining melt phase polycondensation and
solid phase polycondensation; (2), the additive, compatilizer for
polyolefin elastomer to graft multiple monomers, and
polypropylene resin are subjected to melt-blending
granulation in a double-screw extruder, and the dyeable modified
polypropylene resin with the dispersed phase grain
diameter less than 1 mum is prepared; and (3), the dyeable modified polypropylene resin prepared in the step (2) is used as island, alkaline
solubility polyester is used as sea, and the sea-island composite
processing is carried out; and the
fiber is subjected to decrement by the later alkali, and the superfine dyeable
polypropylene fiber with the monofilament
fineness less than 0.2dtex is prepared. According to the superfine dyeable
polypropylene fiber prepared by the method, the
thermostability is high, the
spinning processability is good, and fabric woven by the
fiber has the superior properties of
lightness, mildness, breathability and warm keeping, and is particularly suitable for high-grade
bedding, high-grade underwear and the like.