A method for producing ultrafine fibers suitable for ultrafineness, a method for producing ultrafine fibers, ultrafine fibers suitable for ultrafineness, and ultrafine fibers.

摘要

PROBLEM TO BE SOLVED: To provide a method capable of manufacturing an overall extrafine fiber without remaining a thick core part of the fiber, reducing labour and energy needed for manufacturing the extrafine fiber and enhancing production efficiency of the extrafine fiber by reducing needed processing time.SOLUTION: There is provided a method for manufacturing a fiber splittable into extrafine fibers by conducting a processing treatment to a fiber, by performing both or one of a compression heating treatment A for hydrating a fiber and heating the same under pressure of more than ambient pressure and freeze-thawing treatments N1, N2 for freezing the fiber after hydrating the same and then thawing the same, as the processing treatment.SELECTED DRAWING: Figure 18