Apparatus For Manufacturing Ultrafine Fiber And Method For Manufacturing Ultrafine Fiber

Abstract

The apparatus for producing ultrafine fibers includes a nozzle portion, a laser irradiation unit, and a drawing chamber. The nozzle portion has an inlet for feeding a raw fiber, a first jet outlet which communicates with the inlet and jets a first drawing gas stream for delivering and drawing the raw fiber, and a second jet outlet which is arranged in the periphery of the first jet outlet and jets a second drawing gas stream. The laser irradiation unit on which the nozzle portion is installed irradiates a laser light to the raw fiber delivered from first jet outlet to melt the raw fiber. The drawing chamber draws the melted raw fiber by using the first drawing gas stream and the second drawing gas stream which are jetted from the nozzle portion.

1 . An apparatus for producing ultrafine fibers, comprising:
 a nozzle portion having an inlet for feeding a raw fiber, a first jet outlet which communicates with the inlet and which jets a first drawing gas stream for delivering and drawing the raw fiber, and a second jet outlet which is arranged in a periphery of the first jet outlet and which jets a second drawing gas stream;   a laser irradiation unit which is installed on the nozzle portion to irradiate laser light to the raw fiber delivered from the first jet outlet and melt the raw fiber; and   a drawing chamber for drawing the melted raw fiber by using the first drawing gas stream and the second drawing gas stream which are jetted from the nozzle portion.   
     
     
         2 . The apparatus for producing ultrafine fibers according to  claim 1 , wherein the second drawing gas stream has a slower flow speed than the first drawing gas stream. 
     
     
         3 . The apparatus for producing ultrafine fibers according to  claim 1 , wherein the first and the second drawing gas streams are generated by a pressure difference between inside and outside of the drawing chamber. 
     
     
         4 . The apparatus for producing ultrafine fibers according to  claim 1 , further comprising a speed adjustment mechanism for controlling a flow speed of the second drawing gas stream. 
     
     
         5 . The apparatus for producing ultrafine fibers according to  claim 4 , wherein the speed adjustment mechanism includes a valve or a regulator. 
     
     
         6 . The apparatus for producing ultrafine fibers according to  claim 1 , further comprising a speed controller for adjusting an amount of air flowing to the second jet outlet, wherein the speed controller is operated to control a flow speed of the second drawing gas stream. 
     
     
         7 . The apparatus for producing ultrafine fibers according to  claim 1 , further comprising a sensor for detecting a flow speed or a flow rate of the second drawing gas stream, a speed controller for adjusting an amount of air flowing to the second jet outlet, and a control device for controlling the speed controller based on the flow speed or the flow rate of the second drawing gas stream detected by the sensor and controlling the flow speed of the second drawing gas stream. 
     
     
         8 . The apparatus for producing ultrafine fibers according to  claim 1 , wherein the second jet outlet is provided concentrically on the periphery of the circular first jet outlet, and the second drawing gas stream is generated to surround a periphery of the first drawing gas stream. 
     
     
         9 . The apparatus for producing ultrafine fibers according to  claim 1 , wherein the second jet outlet is holes of a porous metal member installed in the periphery of the first jet outlet. 
     
     
         10 . The apparatus for producing ultrafine fibers according to  claim 1 , wherein the raw fiber is a monofilament comprising a thermoplastic polymer material, or a multifilament comprising a bundle of a plurality of monofilaments. 
     
     
         11 . The apparatus for producing ultrafine fibers according to  claim 1 , wherein the nozzle portion includes a plurality of the inlets, the first jet outlets, and the second jet outlets, wherein the second jet outlets are provided in the peripheries of the first jet outlets, respectively. 
     
     
         12 . A method for producing ultrafine fibers, comprising:
 feeding a raw fiber to an inlet of a nozzle portion and delivering the raw fibers from a first jet outlet which communicates with the inlet to a drawing chamber;   irradiating the raw fiber delivered to the drawing chamber with laser light to melt the raw fiber; and   drawing the melted raw fiber by using a first drawing gas stream for drawing the raw fiber which is jetted from the first jet outlet and a second drawing gas stream which is jetted from a second jet outlet arranged in a periphery of the first jet outlet.   
     
     
         13 . The method for producing ultrafine fibers according to  claim 12 , wherein, during the drawing the melted raw fiber, the second drawing gas stream has a slower flow speed than the first drawing gas stream. 
     
     
         14 . The method for producing ultrafine fibers according to  claim 12 , further comprising feeding the raw fiber to the inlet of the nozzle portion, and generating a pressure difference between inside and outside of the drawing chamber prior to delivering the raw fiber from the first jet outlet which communicates with the inlet to the drawing chamber. 
     
     
         15 . The method for producing ultrafine fibers according to  claim 12 , wherein the drawing the melted raw fiber includes controlling a flow speed of the second drawing gas stream with a speed adjustment mechanism. 
     
     
         16 . The method for producing ultrafine fibers according to  claim 15 , wherein the controlling the flow speed of the second drawing gas stream with the speed adjustment mechanism includes controlling the flow speed of the second drawing gas stream with a valve or a regulator. 
     
     
         17 . The method for producing ultrafine fibers according to  claim 12 , wherein the drawing the melted raw fiber includes operating a speed controller for adjusting an amount of air flowing to the second jet outlet so as to control a flow speed of the second drawing gas stream. 
     
     
         18 . The method for producing ultrafine fibers according to  claim 12 , wherein the drawing the melted raw fiber further comprises detecting a flow speed or a flow rate of the second drawing gas stream by a sensor; and based on the flow speed or the flow rate of the second drawing gas stream detected by the sensor, controlling a speed controller by a control device to control the flow speed of the second drawing gas stream. 
     
     
         19 . The method for producing ultrafine fibers according to  claim 12 , wherein the raw fiber is a monofilament comprising a thermoplastic polymer material, or a multifilament comprising a bundle of a plurality of monofilaments. 
     
     
         20 . The method for producing ultrafine fibers according to  claim 12 , wherein the second jet outlet provided concentrically on the periphery of the circular first jet outlet to draw the melted raw fiber includes generating the second drawing gas stream to surround a periphery of the first drawing gas stream.