Method for manufacturing and device for manufacturing ultrafine fiber nonwoven fabric

Abstract

A spinning die for producing ultrafine fiber nonwoven fabric is made miniaturized and its productivity thereof is enhanced. The spinning die has a substantial cuboid shape and a plurality of nozzle holes is disposed in a longitudinal direction. A slit for jetting hot air is disposed only in one side of the nozzle holes. Thermoplastic polymer is melt blown from the nozzle of the spinning die to obtain ultrafine fibers. Hot air is jetted from the slit disposed at only one side of the nozzle holes. The result is that the ultrafine fibers melt blown in a direction inclined with respect to an axis direction of the nozzle. The blown ultrafine fibers are accumulated by sucking to downward to obtain ultrafine fiber nonwoven fabric.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a National Phase application filed under 35 USC 371 of PCT International Application No. PCT / JP2016 / 070580 with an International Filing Date of Jul. 12, 2016, which claims under 35 U.S.C. § 119(a) the benefit of Japanese Application No. 2015-144966 filed on Jul. 22, 2015, the entire contents of which are incorporated herein by reference.BACKGROUND(a) Technical Field[0002]The present disclosure relates to a method for producing ultrafine fiber (or filament) nonwoven fabric and an apparatus therefor, in particular to the method which has excellent productivity and the apparatus therefor with a reduced size.(b) Description of the Related Art[0003]Hitherto, ultrafine fiber nonwoven fabric has been produced with using a spinning die of a substantial cuboid shape, which has nozzle holes for melt blowing thermoplastic polymer and slits for jetting hot air in both sides of the nozzle holes. The nozzle holes are linearly arrang...

AI Technical Summary

Benefits of technology

The present disclosure suggests that it is not necessary to have slits in both sides of a nozzle hole in a spinning die. The conventional practice of including slits is because hot air is jetted in the direction of the nozzle, which melt blows the thermoplastic polymer and extends the ultrafine fiber to enhance its strength. However, this method does not always result in effective fiber extension because the ultrafine fiber floats in the air. The present disclosure proposes different methods to improve the fiber extension process.

Problems solved by technology

However, the spinning die 1 needs to have the pipes 6, 6, the hot air passages 5, 5 and the slits 4, 4 in both sides of the nozzle hole, to result in a drawback of a large-sized apparatus.

However, it has been found that, even if hot air is jetted to the direction of axis of the ultrafine fiber in the condition, because the ultrafine fiber is floating in the air, almost no extension effects of the fiber are obtained.

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