NONWOVEN FABRIC AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a nonwoven fabric that comprises uniformly dispersed fibers of small fiber diameter, has small average flow pore diameter and shows a variety of excellent functions and provide a method for producing the same. SOLUTION: The nonwoven fabric according to this invention is constituted with the fibers that do not take any bundle form even when they are placed in any positions and has≤0.8μm average flow pore diameter. The average fiber diameter of the constituting fibers is≤1μm and the ratio of standard deviation (Dd) of the fiber diameter of the constituting fibers to the average fiber diameter (Dd/Da) is≤0.2. The nonwoven fabric can be produced through the following steps: (1) the spinning step in which a spinning dope is extruded through nozzles and simultaneously an electric field are allowed to act on the extruded spun dope; (2) the accumulation step where the fibers are accumulated on the collector to form fiber web and (3) the densification step where the fiber web is densified by applying pressure to produce the nonwoven fabric. COPYRIGHT: (C)2005,JPO&NCIPI