JP2012127008A - Method and device for manufacturing nanofiber nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for manufacturing a nanofiber nonwoven fabric, capable of manufacturing a uniform nanofiber nonwoven fabric efficiently.SOLUTION: A method for manufacturing a nanofiber nonwoven fabric, comprises discharging a polymer solution as a thin linear body from a nozzle 1 by activating a blower 4 and a fan 5 and applying a voltage between the nozzle 1 and a collecting material 2 in a housing 3. The polymer solution is explosively extended by electrostatic explosion, to efficiently produce a nanofiber 8 including a polymer having a submicron diameter.

Description

  The present invention relates to a method and apparatus for producing a nanofiber nonwoven fabric on which nanofibers made of a polymer are deposited.

  A charge-induced spinning method (electrospinning method) is known as a method for producing a nanofiber having a submicron-scale diameter made of a polymer. In this charge induction spinning method, a polymer solution is supplied to a needle-like nozzle to which a high voltage is applied, and the polymer solution is ejected linearly from the needle-like nozzle toward a collecting portion. The linear polymer solution is charged, and the diameter of the linear polymer solution is reduced with the evaporation of the solvent of the polymer solution, the charged charge is concentrated, and the Coulomb force acting on the linear polymer solution is increased. When this Coulomb force becomes larger than the surface tension of the linear polymer solution, a phenomenon occurs that the linear polymer solution is stretched explosively (electrostatic explosion phenomenon). By repeating this electrostatic explosion phenomenon, submicron Nanofibers with a diameter (eg 50-1000 nm) are produced.

  By depositing the nanofibers on the collection part, a three-dimensional thin film having a three-dimensional network can be obtained. Also, by forming the nanofiber thick, a highly porous web having a submicron network can be produced. The highly porous web thus produced can be suitably applied to filters, battery separators, polymer electrolyte membranes and electrodes of fuel cells.

  As a method for producing a nanofiber nonwoven fabric, nanofibers produced by a charge-induced spinning method by flowing a polymer solution out of a nozzle are deposited on a movable sheet that can be ventilated as a collection portion, and the lower side of this sheet is A suction method is known (Patent Document 1).

JP 2008-223179 A

  In the configuration shown in Patent Document 1, since suction is only performed from the lower side of the sheet, a part of the nanofibers flying from the discharge unit toward the collection unit is scattered, or the deposition thickness on the collection unit There is a risk that the unevenness of the thickness becomes large.

  An object of the present invention is to solve the conventional problems described above and to provide a method and an apparatus for producing a nanofiber nonwoven fabric that can efficiently produce a uniform nanofiber nonwoven fabric.

  In the method for producing a nanofiber nonwoven fabric according to claim 1, a polymer solution obtained by dissolving a nanofiber raw material polymer in a solvent is directed from a discharge portion to one side of a collection portion to which a voltage is applied between the discharge portion and the polymer solution. In the method for producing a nanofiber nonwoven fabric, a nanofiber is produced by discharging the nanofiber, and the produced nanofiber is collected at the collection section to form a nanofiber nonwoven fabric. A method of manufacturing a nanofiber nonwoven fabric in which the other side of the part is sucked by a gas suction unit and blown by the blowing unit in a direction from the discharge unit toward the collecting unit, and the amount of air generated by the blowing unit is the gas The amount of air generated by the suction means is 30 to 100%.

  The method for producing a nanofiber nonwoven fabric according to claim 2 is characterized in that, in claim 1, the air volume generated by the air blowing means is 30 to 80% of the air volume generated by the gas suction means.

  The method for producing a nanofiber nonwoven fabric according to claim 3 is characterized in that, in claim 1 or 2, the outer periphery of the zone between the discharge part and the collection part is surrounded by an enclosure.

  A method for producing a nanofiber nonwoven fabric according to a fourth aspect is characterized in that, in any one of the first to third aspects, an atmosphere of a zone between the discharge part and the collection part is adjusted.

  The manufacturing method of the nanofiber nonwoven fabric of Claim 5 adjusts the temperature of the atmosphere of the zone between the said discharge part and the collection part in any one of Claims 1 thru | or 4, It is characterized by the above-mentioned. is there.

  The method for producing a nanofiber nonwoven fabric according to claim 6 is characterized in that, in any one of claims 1 to 5, the raw material polymer is a charged polymer or a conductive polymer.

  The apparatus for producing a nanofiber nonwoven fabric according to claim 7 includes a discharge unit that discharges a raw polymer solution of nanofibers, a collection unit that collects nanofibers from the discharge unit on one side, and the discharge unit and the collection unit. A nanofiber nonwoven fabric manufacturing apparatus comprising a means for applying a voltage between the gas collecting unit and the gas collecting unit for sucking the other side of the collecting unit. The apparatus further includes air blowing means for blowing air in a direction from the discharge unit toward the collecting unit.

  An apparatus for producing a nanofiber nonwoven fabric according to an eighth aspect is characterized in that, in the seventh aspect, an enclosure for enclosing the outer periphery of the zone between the discharge part and the collection part is provided.

  An apparatus for producing a nanofiber nonwoven fabric according to a ninth aspect is characterized in that, in the seventh or eighth aspect, a heating means for gas blown by the blowing means is provided.

  The apparatus for producing a nanofiber nonwoven fabric according to claim 10 comprises the humidity adjusting means for adjusting the humidity of the atmosphere between the discharge part and the collection part according to any one of claims 7 to 9. It is what.

  An apparatus for producing a nanofiber nonwoven fabric according to an eleventh aspect is characterized in that, in any one of the seventh to tenth aspects, a heating means for heating the discharge section is provided.

  A nanofiber nonwoven fabric manufacturing apparatus according to a twelfth aspect is characterized in that, in any one of the seventh to eleventh aspects, the nanofiber nonwoven fabric manufacturing apparatus includes a heating means for heating the polymer solution supplied to the discharge unit. is there.

  An apparatus for producing a nanofiber nonwoven fabric according to a thirteenth aspect is characterized in that, in any one of the seventh to twelfth aspects, the raw material polymer is a charged polymer or a conductive polymer.

  In the present invention, not only the collection part is sucked from the opposite side (other side) to the discharge part, but also the air is blown in the direction from the discharge part toward the collection part. Since the fiber (electrospun fiber) maintains a uniform distribution state and does not protrude from the collection part, it will surely deposit on the collection part. Can do. In addition, since the deposit of nanofiber is pressed against the collection part by the gas flow which passes a collection part, it becomes a sheet form in normal cases. According to the present invention, by setting the air volume of the air blowing means to 30% or more of the air volume of the gas suction means, it is possible to suppress the fuzz of the nanofibers deposited on the collection part, and thereby the nanofibers on the collection part Unevenness of the deposited thickness can be reduced. If the air volume of the air blowing means is increased too much, the air volume on the discharge part side (one side) of the collecting part becomes excessive, and the air circulates around the air blowing means, from the discharge part to the collecting part. Although some of the nanofibers flying in the direction may be scattered without being collected by the collecting part, the air volume of the air blowing means is 100% or less of the air volume of the gas suction means, It is possible to prevent the air volume on the discharge unit side from becoming excessive, and to prevent nanofibers from being scattered.

  When the nanofibers are collected in the collection part, the collection part is gradually closed. Therefore, if the air volume of the blowing means and the air volume of the gas suction means are equivalent, the collection part is blocked. Along with this, there is a risk that the air volume of the air blowing means becomes excessive, and a part of the nanofibers flying from the discharge part toward the collecting part may be scattered. By setting the air volume to 80% or less of the air volume, the air volume of the air blowing means is unlikely to be excessive even if the collection of the nanofibers in the collecting section is advanced, and the scattering of the nano fibers can be more reliably prevented over a long period of time.

  By surrounding the outer periphery of the zone between the discharge part and the collection part with an enclosure, a more uniform nanofiber nonwoven fabric can be produced efficiently.

  In addition, by adjusting the humidity and temperature of the gas flow from the discharge part to the collection part, the evaporation rate of the solvent from the nanofibers in flight and the nanofiber nonwoven fabric on the collection part can be controlled. A good nanofiber nonwoven fabric can be produced, which is preferable.

  By heating the discharge part and the polymer solution supplied to the discharge part, gelation and solidification of the polymer solution can be prevented, and the nanofiber nonwoven fabric can be efficiently produced.

It is sectional drawing of the nonwoven fabric manufacturing apparatus which concerns on embodiment. It is sectional drawing of the nonwoven fabric manufacturing apparatus which concerns on embodiment. It is sectional drawing of the nonwoven fabric manufacturing apparatus which concerns on embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. 1 to 3 are cross-sectional views of the nanofiber nonwoven fabric manufacturing apparatus according to each embodiment.

[Nanofiber non-woven fabric manufacturing equipment in Fig. 1]
In FIG. 1, a nozzle 1 serving as a discharge unit for discharging a polymer solution in a thin line shape and a collection material 2 serving as a collection unit for collecting nanofibers generated by discharging from the nozzle 1 are surrounded. It arrange | positions in the housing 3 as a body. In this embodiment, the housing 3 has a cylindrical shape such as a cylindrical shape or a rectangular tube shape, a blower 4 as a blower means is disposed on one end side, and a blower 5 as a gas suction means is provided on the other end side. ing.

  The exhaust fan 5 is disposed on the opposite side of the nozzle 1 with the trapping material 2 interposed therebetween. A polymer solution is supplied to the nozzle 1 via a pipe 6. A high voltage is applied between the nozzle 1 and the collector 2 by the voltage source 7. In FIG. 1, a high voltage is applied so that the trapping material 2 is positive and the nozzle 1 is negative. This polarity may be reversed. The applied voltage is preferably about 1 kV to 100 kV, particularly about 5 kV to 100 kV, but is not limited thereto.

  The collection material 2 is made of a material that allows ventilation, such as a perforated plate, a mesh, a woven fabric, and a non-woven fabric. It may be a perforated plate or a mesh having a woven fabric or non-woven fabric arranged on the plate surface on the nozzle 1 side.

  In the nanofiber nonwoven fabric manufacturing apparatus configured as described above, when the blower 4 and the exhaust fan 5 are operated, a voltage is applied between the nozzle 1 and the collecting material 2, and the polymer solution is discharged from the nozzle 1, the nozzle The polymer solution is discharged from 1 as a thin linear body. As the solvent of the polymer solution evaporates from the linear body, the diameter of the linear body is reduced, and the charged charge is concentrated accordingly, and the Coulomb force exceeds the surface tension of the linear polymer solution. At that point, a primary electrostatic explosion occurred and the film was stretched explosively, and then the solvent further evaporated, similarly a secondary electrostatic explosion occurred and the film was stretched explosively, and in some cases, a third electrostatic explosion occurred. By being drawn, nanofibers 8 made of a polymer having a submicron diameter are efficiently produced.

  In the present invention, at the time of manufacturing the nonwoven fabric, the blower 4 and the exhaust fan 5 are operated so that the air volume of the blower 4 is 30 to 100%, preferably 30 to 80% of the air volume of the exhaust fan 5.

  The nanofibers 8 are collected and deposited on the collection material 2 to produce a nonwoven fabric. After a predetermined amount of non-woven fabric is produced, the above manufacturing operation is stopped, the collecting material 2 is taken out, and a non-woven fabric is obtained.

  In the present invention, when the non-woven fabric is manufactured, the blower 4 and the exhaust fan 5 are operated so that the air volume of the blower 4 becomes 30% or more of the air volume of the exhaust fan 5. This can reduce the unevenness of the deposited thickness of the nanofibers 8 on the trapping material 2. If the air volume of the blower 4 is increased too much, the air volume on the nozzle 1 side of the trapping material 2 becomes excessive, and the wind circulates around the blower 4, from the nozzle 1 toward the trapping material 2. Although some of the flying nanofibers 8 may be scattered without being collected by the collecting material 2, the air volume of the blower 4 is set to 100% or less of the air volume of the exhaust fan 5. It is possible to prevent the air volume on the nozzle 1 side from becoming excessive, and to prevent the nanofibers 8 from being scattered.

  Note that when the nanofibers 8 are collected on the collecting material 2, the collecting material 2 is gradually closed. Therefore, when the air volume of the blower 4 and the air volume of the exhaust fan 5 are equal, this trapping is performed. Although the air volume of the blower 4 may become excessive with the blockage of the collecting material 2, the nanofiber 8 to the collecting material 2 can be obtained by setting the air volume of the blower 4 to 80% or less of the air volume of the exhaust fan 5. However, the air volume of the blower 4 is unlikely to be excessive even when the collection of the air has progressed, and the scattering of the nanofibers 8 can be more reliably prevented over a long period of time.

  In this embodiment, the housing 3 is provided so as to surround the zone between the nozzle 1 and the collecting material 2, the blower 4 is provided in the upstream portion of the housing 3, and the exhaust fan 5 is provided downstream of the collecting material 2. Since it is arranged on the side, the nanofibers 8 flying from the nozzle 1 toward the collecting material 2 are collected in the collecting material 2 in a uniformly distributed state without being scattered around. Therefore, the non-woven fabric on the collection material 2 has less unevenness in quality, characteristics, and thickness.

[Nanofiber non-woven fabric manufacturing equipment in Fig. 2]
2, in the manufacturing apparatus of FIG. 1, the housing 3 is extended to the upstream side, the blower 4 is arranged on the most upstream side, an air heater 10 and a water vapor outlet between the blower 4 and the nozzle 1. The water vapor supply device 11 having 11a is installed. The air heater 10 is for heating the air sent by the blower 4, and the water vapor supply device 11 is for adjusting the humidity by adding water vapor to the atmosphere.

  The other structure of FIG. 2 is the same as that of FIG. 1, and the same code | symbol has shown the same part. Also in this manufacturing apparatus, at the time of manufacturing the nonwoven fabric, the blower 4 and the exhaust fan 5 are operated so that the air volume of the blower 4 is 30 to 100%, preferably 30 to 80% of the air volume of the exhaust fan 5.

  Also with the manufacturing apparatus of FIG. 2, a nanofiber nonwoven fabric with small variations in quality, characteristics and thickness is manufactured as in FIG.

  In the manufacturing apparatus of FIG. 2, the air is heated by the air heater 10 to promote the evaporation of the solvent from the fine-line polymer solution in flight, or to adjust the humidity (water vapor concentration) in the atmosphere in the housing 3. The evaporation rate of the solvent from the fine linear polymer solution can be controlled, and the length and diameter of the nanofiber can be adjusted accordingly.

  The other functions and effects of the manufacturing apparatus of FIG. 2 are the same as those of the manufacturing apparatus of FIG.

[Nanofiber non-woven fabric manufacturing equipment in Fig. 3]
The manufacturing apparatus shown in FIGS. 1 and 2 manufactures nanofiber nonwoven fabrics batchwise, while FIG. 3 is for continuously manufacturing nanofiber nonwoven fabrics.

  In this embodiment, the non-woven fabric 40 is manufactured by continuously moving the collection material 20 and depositing nanofibers on the collection material 20.

  The trapping material 20 is an endless belt made of a material that can be ventilated and bent, such as a mesh, a woven fabric, and a non-woven fabric. It is configured to move horizontally by being guided by rollers 23 and 23. The upper traveling portion of the collecting material 20 moves along the upper surface of a porous plate 34 described later.

  Wind from the blower 30 is introduced into the upper housing 32 through the duct 31. The lower surface of the upper housing 32 is open, and the lower end of the upper housing 32 is disposed close to the upper traveling portion of the collection material 20. A large number of nozzles (discharge units) 33 are arranged in the upper housing 32. A polymer solution is supplied to each nozzle 33 from a polymer solution tank (not shown) via a pump (not shown), and is discharged from the nozzle 33 in a thin line shape.

  A lower housing 35 is disposed on the lower side of the upper traveling portion of the collecting material 20 so as to face the upper housing 32. A porous plate 34 is attached to the upper end of the lower housing 35, and the upper traveling portion of the collecting material 20 moves along the upper surface of the porous plate 34.

  The lower housing 35 is connected to an exhaust fan 37 through a duct 36.

  A high voltage is applied between the nozzle 33 and the perforated plate 34 via a voltage source 38.

  In the nanofiber nonwoven fabric manufacturing apparatus configured as described above, the blower 30 and the exhaust fan 37 are operated, the collection material 20 is rotated endlessly, a voltage is applied between the nozzle 33 and the porous plate 34, When the polymer solution is discharged, the polymer solution is discharged from the nozzle 33 as a thin linear body. As the solvent of the polymer solution evaporates from the linear body, the diameter of the linear body is reduced, and the charged charge is concentrated accordingly, and the Coulomb force exceeds the surface tension of the linear polymer solution. At that point, a primary electrostatic explosion occurred and the film was stretched explosively, and then the solvent further evaporated, similarly a secondary electrostatic explosion occurred and the film was stretched explosively, and in some cases, a third electrostatic explosion occurred. By being drawn, nanofibers 39 made of a polymer having a submicron diameter are efficiently generated.

  Also in this nanofiber nonwoven fabric manufacturing apparatus, at the time of manufacturing the nonwoven fabric, the blower 4 and the exhaust fan 5 are operated so that the air volume of the blower 30 is 30 to 100%, preferably 30 to 80% of the air volume of the exhaust fan 37.

  The nanofibers 39 are collected and deposited on the collection material 20, and the nonwoven fabric 40 is generated. The nonwoven fabric 40 is peeled off from the collecting material 20 in the vicinity of the driving roller 21 and taken out.

  Also in this embodiment, an upper housing 32 is provided so as to surround a zone between the nozzle 33 and the collecting material 20, and a blower 30 is provided in the upper housing 32 so as to blow air from above. Since the exhaust fan 37 is provided so as to suck the lower side of the trapping material 20 through the lower housing 35 and the duct 36, the nanofibers 39 flying from the nozzle 33 toward the trapping material 20 are scattered around. Without being collected and collected in the collecting material 20 in a uniformly distributed state. Therefore, the non-woven fabric 40 on the collection material 20 has less unevenness in quality, characteristics, and thickness.

  Other functions and effects of the manufacturing apparatus of FIG. 3 are the same as those of the manufacturing apparatus of FIG.

  In the manufacturing apparatus shown in FIG. 3, an air heater or a steam supply device may be disposed in the duct 31 or the upper housing 32.

[Raw material of nanofiber]
The raw material polymer for nanofibers includes polyolefins such as polyethylene and polypropylene, polyethers such as polyethylene oxide and polypropylene oxide, fluororesins such as PTFE, CTFE, PFA, polyvinylidene fluoride (PVDF), and halogenated polyolefins such as polyvinyl chloride. , Polyamide such as nylon-6, nylon-66, urea resin, phenolic resin, melamine resin, polystyrene, cellulose, cellulose acetate, cellulose nitrate, polyetherketone, polyetherketoneketone, polyetheretherketone, polysulfone, polyethersulfone , Polyimide, polyetherimide, polyamideimide, polybenzimidazole, polycarbonate, polyethylene terephthalate, polybutylene Terephthalate, polyphenylene sulfide, polyacrylonitrile, polyether nitrile, but polyvinyl alcohol and materials including these copolymers can be used, not limited thereto. In particular, it is not limited to one kind of material, and various materials can be selected as necessary. However, a chargeable or conductive polymer is preferable because the effect of the present invention is remarkable because fuzzing is likely to occur in the collecting portion by electrospinning. In addition, you may mix other polymers, such as polyolefin and polyether, with a chargeable or electroconductive polymer.

Examples of the conductive polymer include polyacetylene and polythiophenes.
As the chargeable polymer, a perfluorocarbon sulfonic acid polymer (Nafion (registered trademark), Fumion (trade name)), a sulfonate group, a carboxyl group, and a primary to quaternary amino group were added to the skeleton uncharged polymer. Mention may be made of polymers. Examples of the non-chargeable polymer serving as the skeleton include polyolefin, polystyrene, polysulfone, polyester, and polyvinylidene fluoride.

  As the solvent, alcohols such as methanol, ethanol, propanol and isopropanol, N-methylpyrrolidone, dimethylacetamide, dimethylformamide, fluorinated solvents and the like are preferable, but water is added in an amount of 10 to 1000 volumes with respect to 100 parts by volume of the solvent. Partially mixed solvents are also suitable.

  The nanofiber may be provided with at least one of a cation exchange group, an anion exchange group, and a chelate group.

  Examples of ion exchange groups include sulfonic acid groups, phosphoric acid groups, phosphonic acid groups, phosphinic acid groups, carboxylic acid groups, hydroxyl groups, phenol groups, quaternary ammonium groups, primary to tertiary amine groups, pyridine groups, and amide groups. There is not this limit. These functional groups may be not only H-type and OH-type but also salt-type such as Na.

  The method for introducing the functional group is not particularly limited, and various methods can be employed. For example, in the case of polystyrene, a sulfonic acid group can be introduced by adding an appropriate amount of paraformaldehyde to a sulfuric acid solution and crosslinking by heating. In the case of polyvinyl alcohol, a functional group can be introduced by allowing a trialkoxysilane group, a trichlororosilane group, or an epoxy group to act on the hydroxyl group. If the functional group cannot be introduced directly depending on the material, first introduce a highly reactive monomer such as styrene (referred to as a reactive monomer) and then introduce the functional group in two or more stages. Then, a target functional group may be introduced. These reactive monomers include, but are not limited to, glycidyl methacrylate, styrene, chloromethyl styrene, acrolein, vinyl pyridine, acrylonitrile and the like. The functional group may be introduced before forming the nanofiber, but when the fiber is focused, a polymer or resin having ion exchange ability dissolved or pulverized may be applied or kneaded. An ion exchange group may be introduced by bonding by chemical reaction. Examples of the fluorine-based polymer into which a functional group is introduced include commercially available Nafion.

[Other embodiments]
In the present invention, a heater for heating the nozzles 1 and 33 and a heater (heater, heat exchanger, etc.) for heating the polymer solution supplied to the nozzle to 30 to 90 ° C., particularly about 30 to 60 ° C. It may be provided. By heating the nozzle or the polymer solution to be supplied to the nozzle in this way, gelation and solidification of the polymer solution can be prevented, and the nanofiber nonwoven fabric can be efficiently produced.

  In the present invention, the exhaust air from the exhaust fan may be sent to the suction side of the blower.

<Examples 1 to 5 and Comparative Example 1>
[Example 1]
A polymer solution for producing nanofibers was prepared by dissolving 10 parts by weight of commercially available Nafion (sulfonic acid group-introduced polytetrafluoroethylene) and 10 parts by weight of polyvinylidene fluoride in 80 parts by weight of dimethylacetamide.

  This polymer solution was supplied to the nozzle 1 of FIG. 1 over 480 minutes to produce nanofibers. Other conditions are as follows.

Nozzle diameter: 320 μm
Amount ejected from nozzle: 0.1 mL / min
Distance between nozzle and collector 2: 80 mm
Housing cross section: 2800cm ²
Air volume and exhaust air volume: 30000L / min
Humidity: 50%
Temperature: Room temperature Applied voltage: 50 kV

As a result, a nonwoven fabric having an area of 2800 cm ² and a thickness of 70 μm was produced. The average fiber diameter of the nanofiber was 300 μm.

[Examples 2 and 3]
A nonwoven fabric was produced under the same conditions except that the production time in Example 1 was 360 minutes (Example 2) or 240 minutes (Example 3). As a result, a nonwoven fabric having a thickness of 53 μm was produced in Example 2, and a nonwoven fabric having a thickness of 35 μm was produced in Example 3. From this result, it was recognized that the thickness of the resulting nonwoven fabric can be changed by changing the production time.

[Examples 4 and 5]
A nonwoven fabric was manufactured under the same conditions as in Example 1, except that the amount of air blown and exhausted air was 20000 L / min (Example 4) or 15000 L / min (Example 5). As a result, a nonwoven fabric having a thickness of 58 μm was produced in Example 4, and a nonwoven fabric having a thickness of 35 μm was produced in Example 5. From this result, it was recognized that the thickness of the resulting nonwoven fabric can be changed by changing the air volume.

[Comparative Example 1]
Except that the blower 4 and the housing 3 were removed, an attempt was made to produce a nonwoven fabric using the same equipment as in Example 1. However, most of the nanofibers were scattered and the production efficiency of the nonwoven fabric was low.

<Examples 6 to 13 and Comparative Examples 2 and 3>
[Examples 6 to 13]
The air volume of the blower 4 is 30% (Example 6), 40% (Example 7), 50% (Example 8), 60% (Example 9), 70% (Example 10) of the air volume of the exhaust fan 5. The nonwoven fabric was manufactured in the same manner as in Example 1 except that the output of the blower 4 was adjusted to 80% (Example 11), 90% (Example 12), and 100% (Example 13). .

[Comparative Example 2]
A nonwoven fabric was produced in the same manner as in Example 1 except that the output of the blower 4 was adjusted so that the air volume of the blower 4 was 20% of the air volume of the exhaust fan 5.

[Comparative Example 3]
A nonwoven fabric was produced in the same manner as in Example 1 except that the output of the blower 4 was adjusted so that the air volume of the blower 4 was 110% of the air volume of the exhaust fan 5.

  Table 1 shows specific air volumes of the blower 4 and the exhaust fan 5 in Examples 6 to 13 and Comparative Examples 2 and 3, respectively.

  In the nonwoven fabric manufacturing steps of Examples 6 to 13 and Comparative Examples 2 and 3, whether the nanofibers 8 deposited on the collection material 2 were fluffed was visually observed. Further, on the nozzle 1 side of the collecting material 2, it was visually observed whether or not there are nanofibers 8 that fly up (scatter) without being collected by the collecting material 2. The results are shown in Table 1.

  As apparent from Table 1, in Examples 6 to 11 in which the air volume of the blower 4 was 30 to 80% of the air volume of the exhaust fan 5, all were deposited on the collection material 2 in the nonwoven fabric manufacturing process. The nanofibers 8 were not fluffed, and the nanofibers 8 did not rise from the collection material 2 to the nozzle 1 side.

  Even in Examples 12 and 13 in which the air volume of the blower 4 was 90% and 100% of the air volume of the exhaust fan 5, the nanofibers 8 deposited on the collecting material 2 were not fuzzy in the nonwoven fabric manufacturing process. Also in Examples 12 and 13, the nanofibers 8 did not rise from the trapping material 2 to the nozzle 1 side immediately after the start of the production of the nonwoven fabric. As the fiber 8 was collected, the nanofiber 8 gradually rose from the collection material 2 to the nozzle 1 side. This is because, as the nanofibers 8 are collected in the collection material 2, the collection material 2 is closed, and on the nozzle 1 side of the collection material 2, the air volume of the blower 4 is gradually compared with the air volume of the exhaust fan 5. Because it became excessive.

  In Comparative Example 2 in which the air volume of the blower 4 was 20% of the air volume of the exhaust fan 5, the nanofiber 8 did not rise from the collection material 2 to the nozzle 1 side in the nonwoven fabric manufacturing process. The nanofibers 8 deposited on the material 2 became fuzzy. This is because the nanofibers 8 were not sufficiently pressed against the collection material 2 by the wind pressure from the blower 4.

  In Comparative Example 3 in which the air volume of the blower 4 was 110% of the air volume of the exhaust fan 5, the nanofibers 8 deposited on the collection material 2 did not fluff in the nonwoven fabric manufacturing process. The nanofiber 8 rose from 2 to the nozzle 1 side. This is because the air volume of the blower 4 is excessive compared to the air volume of the exhaust fan 5.

  As apparent from the above, in Examples 6 to 13 in which the air volume of the blower 4 is 30 to 100% of the air volume of the exhaust fan 5, the fuzz of the nanofiber 8 and the soaring from the collecting material 2 in the nonwoven fabric manufacturing process Can be prevented. In particular, in Examples 6 to 11 in which the air volume of the blower 4 is 30 to 80% of the air volume of the exhaust fan 5, it is possible to prevent the nanofiber 8 from flying up from the collecting material 2 over a long period of time.

DESCRIPTION OF SYMBOLS 1,33 Nozzle 2,20 Collection material 3 Housing 4,30 Blower 5,37 Ventilation machine 6 Polymer solution supply part 7,38 Voltage source 8,39 Extra fine fiber 10 Air heater 11 Water vapor supply device 20 Collection material 21,22 Drive Roller 23 Guide roller 30 Blower 31, 36 Duct 32 Upper housing 33 Nozzle 34 Perforated plate 35 Lower housing 37 Ventilator 40 Nonwoven fabric

Claims (13)

A nanofiber is generated by discharging a polymer solution in which a raw material polymer of nanofiber is dissolved in a solvent from a discharge portion toward one side of a collecting portion to which a voltage is applied between the discharge portion and the generated nanofiber In the method for producing a nanofiber nonwoven fabric, a fiber is collected at the collection portion to form a nanofiber nonwoven fabric.
In the manufacturing method of the nanofiber nonwoven fabric which is structured so as to allow ventilation of the collection part and sucks the other side of the collection part by the gas suction means and blows by the blowing means in the direction from the discharge part toward the collection part. There,
A method for producing a nanofiber nonwoven fabric, characterized in that the air volume generated by the blowing means is 30 to 100% of the air volume generated by the gas suction means.   2. The method for producing a nanofiber nonwoven fabric according to claim 1, wherein the air volume generated by the air blowing unit is 30 to 80% of the air volume generated by the gas suction unit.   3. The method for producing a nanofiber nonwoven fabric according to claim 1, wherein an outer periphery of a zone between the discharge unit and the collection unit is surrounded by an enclosure.   The method for producing a nanofiber nonwoven fabric according to any one of claims 1 to 3, wherein an atmosphere in a zone between the discharge unit and the collection unit is adjusted.   The method for producing a nanofiber nonwoven fabric according to any one of claims 1 to 4, wherein the temperature of the atmosphere in a zone between the discharge unit and the collection unit is adjusted.   The method for producing a nanofiber nonwoven fabric according to any one of claims 1 to 5, wherein the raw material polymer is a charged or conductive polymer. A discharge unit for discharging a solution obtained by dissolving a raw material polymer of nanofibers in a solvent;
A collection unit that collects nanofibers from the discharge unit on one side;
Means for applying a voltage between the discharge section and the collection section;
In the nanofiber nonwoven fabric manufacturing apparatus equipped with
It is configured so that the collection part can be ventilated,
Gas suction means for sucking the other side of the collection part;
An apparatus for producing a nanofiber nonwoven fabric, further comprising: air blowing means for blowing air in a direction from the discharge part toward the collecting part.   8. The apparatus for producing a nanofiber nonwoven fabric according to claim 7, further comprising an enclosure that surrounds an outer periphery of a zone between the discharge unit and the collection unit.   9. The apparatus for producing a nanofiber nonwoven fabric according to claim 7, further comprising gas heating means for heating the gas blown by the blowing means.   The apparatus for producing a nanofiber nonwoven fabric according to any one of claims 7 to 9, further comprising humidity adjusting means for adjusting the humidity of the atmosphere between the discharge section and the collection section.   The apparatus for producing a nanofiber nonwoven fabric according to any one of claims 7 to 10, further comprising discharge portion heating means for heating the discharge portion.   The apparatus for producing a nanofiber nonwoven fabric according to any one of claims 7 to 11, further comprising heating means for heating the polymer solution supplied to the discharge unit.   The apparatus for producing a nanofiber nonwoven fabric according to any one of claims 7 to 13, wherein the raw material polymer is a charged or conductive polymer.

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