LDPE/PA6 sea-island fiber and preparation method thereof

The invention relates to LDPE/PA6 sea-island fiber and a preparation method thereof. The crystallinity of LDPE in the LDPE/PA6 sea-island fiber is less than or equal to 11%. The preparation method comprises the following steps of (1) preparing raw materials: adopting LDPE and PE wax as a sea phase material, and adopting PA6 as an island phase material, wherein the mass of the PE wax is 0.2-0.8 wt% of that of the LDPE; (2) performing spinning: preparing the LDPE/PA6 sea-island fiber by adopting a double-screw sea-island composite spinning method, wherein the spinning speed is 350-800 m/min; (3) performing cooling: performing cooling to obtain sea-island fiber nascent filaments, wherein a blowing mode is the combination of annular air suction and annular air blowing; (4) performing bundling and oiling; (5) performing drafting: drafting the bundled and oiled fiber in a water bath at the drafting temperature of 90-95 DEG C; (6) performing crimping; and (7) performing loosening and setting to obtain the LDPE/PA6 s