Topic of this invention, is superior in lightweight Characteristic and uniformity, furthermore, strength to be high, it is something which designates that the span bond nonwoven fabrics which consist of the hollow fiber of the small fiber where has flexibility are obtained as purpose, this invention is the span bond nonwoven fabrics which feature that it consists of the hollow fiber of the propylene polymer where description below (a) - (c) satisfies requirement.(A) the C-axis orientation at least 0.85,(B) average fiber diameter 5 - 20 millimicrons, and(C) hollow factor 5 - 30%.本発明の課題は、軽量性、均一性に優れ、しかも、強度が高く、柔軟性を有する細繊維の中空繊維からなるスパンボンド不織布を得ることを目的とするものであり、本発明は、下記(a)~(c)の要件を満たすプロピレン系重合体の中空繊維からなることを特徴とするスパンボンド不織布である。(a)C軸配向度が少なくとも0.85、(b)平均繊維径が5~20μm、及び(c)中空率が5~30%。
