Abstract: A conductive composite fiber is formed from a polymer containing conductive carbon black in a polyamide resin as a conductive layer and thermoplastic resin as a nonconductive layer that is exposed in three or more locations on the outside surface of the fiber in a cross section, the coefficient of variation in the surface area of each conductive layer in a fiber cross section is 10% or less, and the average value of the area specific resistance is 4 log (?·cm). The variation in the fiber surface specific resistance is suppressed and the variation in the exposed surface area of each conductive layer polymer in a fiber cross section is suppressed by exposure of the conductive layer in three or more locations on the fiber surface, crimping of the original yarn is suppressed by equal disposition, and antistatic performance for woven and knitted fabrics and carpets is improved.

Abstract: A polyphenylene sulfide monofilament is characterized by having a continuous heat-shrinking stress variation of at most 5% and a size uniformity (U %, Normal value) of at most 1.2%; and a drum-shaped fiber package includes the wound polyphenylene sulfide monofilament described. The polyphenylene sulfide monofilament has a very small aperture variation rate and is optimal for high-precision filters.

Abstract: A drum-shaped package formed of a poly(lactic acid)-based monofilament 50 wt. % or more of which is constituted from lactic acid monomer, the drum-shaped package being characterized in that the dry heat shrinking stress of the monofilament in the innermost layer section of the package is 0.04 cN/dtex or less. The drum-shaped package formed of a poly(lactic acid)-based monofilament for which gauze fabric quality and higher order passability during weaving are excellent.

Abstract: A polyphenylene sulfide monofilament is characterized by having a continuous heat-shrinking stress variation of at most 5% and a size uniformity (U %, Normal value) of at most 1.2%; and a drum-shaped fiber package includes the wound polyphenylene sulfide monofilament described. The polyphenylene sulfide monofilament has a very small aperture variation rate and is optimal for high-precision filters.