METHOD FOR PRODUCING ACRYLIC FIBER BUNDLE AND METHOD FOR PRODUCING CARBON FIBER BUNDLE

• Main Authors: HAYASHIDA, Kengo, NAKANO, Masaki, ENDO, Hirotada
• Format: Patent
• Language: English; French; German
• Published: 22.07.2020
• Subjects: APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBONFILAMENTS; CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS,THREADS, FIBRES, BRISTLES OR RIBBONS; MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OFARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES ORRIBBONS; NATURAL OR ARTIFICIAL THREADS OR FIBRES; SPINNING; TEXTILES

It is an object of the present invention to sufficiently clean an acrylic fiber bundle in a cleaning step in steps of producing the acrylic fiber bundle, to prevent mixing from occurring between thread bundles adjacent to each other, and to prevent fuzz of single fibers from occurring, in order to produce a high-quality acrylic fiber and carbon fiber. The present invention is a method for producing an acrylic fiber bundle in which an acrylic polymer solution is spun to make a coagulated thread bundle, and the coagulated thread bundle is then subjected to at least an in-bath treatment step and an oil agent application step. The in-bath treatment step includes an in-bath cleaning step. The in-bath cleaning step is a step in which the plurality of coagulated thread bundles travel in parallel and are cleaned in one or more washing baths including an inflow portion and an outflow portion for a cleaning solution. At least one of the washing baths is a counterflow washing bath in which the cleaning solution flows into from the inflow portion located at a lower stream side position of a traveling direction of the coagulated thread bundles, and flows out from the outflow portion located at an upper stream side position of the traveling direction of the coagulated thread bundles. An average of coefficients of variation of linear speeds of the cleaning solution in the inflow portion of the counterflow washing bath is 0.30 or less. An average of coefficients of variation of linear speeds of the cleaning solution in the outflow portion of the counterflow washing bath is 0.30 or less.