KR102281702B1 - Non-woven fabric manufacturing method and apparatus - Google Patents

Abstract

A nonwoven fabric manufacturing method and apparatus are provided which suppress that the side part of a long nonwoven fabric becomes thin, and suppresses enlargement of a manufacturing apparatus.
The nonwoven fabric manufacturing apparatuses 10 and 80 discharge the solution 23 from the nozzles 31a to 31e in a state in which a voltage is applied between the collecting material 43 and the nozzles 31a to 31e to produce the nonwoven fabric 11 . manufacture The nozzles 31a to 31e are arranged in the width direction of the collecting material 43 and the charging belt 37 . Extended members 71 and 81 are provided outside the nozzles 31a and 31e in a state away from the tips 31D of these nozzles 31a and 31e. The continuous members 71 and 81 are charged with the same polarity as the nozzles 31a and 31e, and the solution 23 directed to the collecting material 43 is drawn inward in the width direction.

Description

Non-woven fabric manufacturing method and apparatus

The present invention relates to a method and apparatus for manufacturing a nonwoven fabric.

For example, there is a nonwoven fabric formed of so-called nanofibers having a nano-order diameter of several nm or more and less than 1000 nm. As a method for producing a nonwoven fabric formed of nanofibers, there is a method using a field spinning method (there is also an electrospinning method or an electro-deposition method). This method is performed by using an electrospinning device having a liquid extracting unit, a collector, and a power source (hereinafter referred to as a first power source), and applying a voltage between the liquid extracting unit and the collector by the first power source, whereby, for example, For example, the discharge part is charged to positive and the collector to negative. In a state in which a voltage is applied, a solution in which a nanofiber material (hereinafter referred to as a nanofiber material) is dissolved in a solvent is discharged from the opening of the liquid extraction unit. The solution from the extraction part forms nanofibers while being drawn to the collector, and the nanofibers are collected as a nonwoven fabric on the collector.

Patent Document 1 describes a technique for arbitrarily changing the shape and/or shape of a structure, such as a nonwoven fabric, formed of nanofibers by providing a spatial electric field control unit for controlling the electric field between the liquid extraction unit and the collector, there is. The spatial electric field control unit changes the spatial electric field by, for example, a potential difference, and includes a second power source different from the first power supply for applying a voltage to the liquid outlet and the collector, and an electrode for controlling the spatial electric field for controlling the space electric field. be prepared The electrode for spatial electric field control controls the flying direction of the nanofiber toward the collector, etc. by applying the voltage controlled from the second power supply.

By the way, there is a request for producing a long nonwoven fabric formed of nanofibers. This is because, for example, a sheet-like nonwoven fabric having various dimensions can be obtained only by cutting, for example, by making it elongate, so that its use is widened. Advantageously, Patent Document 2 describes a technique for producing a long nonwoven fabric by moving a long collector in the longitudinal direction and discharging a solution from each of a plurality of openings in the liquid extraction unit. The plurality of openings are formed in a row in the longitudinal direction of the collector. This patent document 2 is provided with electrodes extending in the arranging direction of a plurality of openings, and by means of the electrodes, the solution discharged from the liquid extraction unit is the length of a straight line that virtually connects the opening and the collector, with respect to the distance between the liquid extraction unit and the collector. lengthening the emergency route of Thereby, the volatilization amount of the solvent from a solution is raising.

Patent Document 1: Japanese Patent Application Laid-Open No. 2009-024292 Patent Document 2: Japanese Patent Application Laid-Open No. 2011-208340

However, according to the technique described in Patent Document 2, even if the nanofibers are uniform, it is difficult to control the collection area in the collector of the nanofibers and to equalize the collection amount in the collection area. For this reason, as for the thickness of the elongate nonwoven fabric obtained, the side part in the width direction tends to become thin compared with a center part. In addition, the technique described in Patent Document 2 has a limit in the width of the obtained nonwoven fabric because a plurality of openings in the liquid extraction unit are arranged in the longitudinal direction of the collector. Advantageously, in order to manufacture a nonwoven fabric with a wider width, in patent document 2, it is conceivable to form a plurality of openings in a row in the width direction of the collector. However, even in the case where a plurality of openings are formed in a row in the width direction of the collector in this way, the side portion in the width direction is similarly thinner than the central portion. In this way, when the side portion is thinner than the central portion, the side portion remains as a peeling residue on the collector in the case of peeling the nonwoven fabric from the collector.

Advantageously, the technique described in Patent Literature 1 controls the flying direction of the nanofibers toward the collector by controlling the spatial electric field, and there is a certain effect in controlling the collection area. However, since the second power source for controlling the spatial electric field must be one capable of applying a high voltage, the manufacturing apparatus becomes large.

Therefore, an object of this invention is to provide the nonwoven fabric manufacturing method and apparatus which suppress that the side part of a long nonwoven fabric becomes thin, and suppresses enlargement of a manufacturing apparatus.

The nonwoven fabric manufacturing method of the present invention has a liquid extraction step and a collecting step, and in a state in which a voltage is applied between the collector and the plurality of nozzles, from each of the plurality of nozzles toward the collector, the nanofiber material is dissolved in a solvent By discharging the solution, a nonwoven fabric formed of nanofibers is produced. In the liquid extraction step, the solution is discharged from each tip of a plurality of nozzles arranged in the width direction of a long collector moving in the longitudinal direction. A collection process collects the solution which came out of a nozzle by a collector as a nonwoven fabric.

An end edge in the said width direction of the solution which goes to a collector is drawn inward in the width direction of a collector by a continuous member. The extending member is provided outside the outermost nozzle in the width direction among the plurality of nozzles in a state away from the tip of the outermost nozzle, and extends toward the collector. The continuous member is charged with the same polarity as the plurality of nozzles. By electrically connecting the nozzle and the continuous member, or by connecting the nozzle and the continuous member in parallel to a power source for applying a voltage, the continuous member is charged with the same polarity as the plurality of nozzles.

It is preferable that the surface of the inner side of the continuous member in the said width direction of a collector becomes close to the center in the width direction of a collector as it goes toward a collector from an outermost nozzle.

The distance between the continuous member and the tip of the outermost nozzle is preferably 5 mm or more.

It is preferable that the continuous member is formed of an acrylic resin or a fluororesin.

The nanofiber material is at least any one of cellulose triacetate, cellulose diacetate, cellulose propionate, cellulose butylate, cellulose acetate propionate, nitrocellulose, ethyl cellulose, and carboxymethyl ethyl cellulose. it is preferable

The nonwoven fabric manufacturing apparatus of the present invention includes a long collector, a plurality of nozzles, a power source, and a continuous member, and in a state in which a voltage is applied between the collector and the plurality of nozzles, from each tip of the plurality of nozzles. A nonwoven fabric formed of nanofibers is produced by discharging a solution in which the nanofiber material is dissolved in a solvent toward the collector. The collector moves in the longitudinal direction. A plurality of nozzles are arranged in the width direction of the collector. The power supply applies a voltage between the nozzle and the collector. The extending member is provided outside the outermost nozzle in the width direction among the plurality of nozzles in a state away from the outermost nozzle, and extends toward the collector. The continuous member is charged with the same polarity as the plurality of nozzles. The continuous member is electrically charged with the plurality of nozzles by being electrically connected to the nozzle or by being connected in parallel with the nozzle to a power source.

It is preferable that the surface of the inner side of the continuous member in the said width direction of a collector becomes close to the center in the said width direction of a collector as it goes toward a collector from an outermost nozzle.

ADVANTAGE OF THE INVENTION According to this invention, the enlargement of a manufacturing apparatus can be suppressed and the elongate nonwoven fabric by which the side part thinning was suppressed can be manufactured.

1 is a schematic diagram of a nonwoven fabric manufacturing facility.
2 is a schematic view of a nonwoven fabric manufacturing apparatus.
3 is a schematic diagram of a nonwoven fabric manufacturing facility.
4 is a schematic view of a nonwoven fabric manufacturing apparatus.

1 : is a schematic diagram of the nonwoven fabric manufacturing apparatus 10 which is an example of embodiment of this invention. The nonwoven fabric manufacturing apparatus 10 is for manufacturing the nonwoven fabric 11 . The nonwoven fabric 11 can be used, for example, as a wiping cloth, a filter, or a medical nonwoven fabric (referred to as a drape) applied to a wound or the like.

The nonwoven fabric 11 is formed of nanofibers 12 , and the nanofibers 12 are formed by an electrospinning method. The nanofiber 12 has a diameter in the range of 50 nm or more and 2000 nm or less, and is generally 400 nm in the present embodiment.

The nonwoven fabric manufacturing apparatus 10 is connected to the solution preparation unit 21 by a pipe 22 . The solution preparation unit 21 is for preparing a solution 23 for forming the nanofibers 12 . The solution preparation unit 21 prepares (prepares) the solution 23 by dissolving the nanofiber material 25 constituting the nanofiber 12 in a solvent 26 of the nanofiber material. The solution 23 prepared by the solution preparation unit 21 is guided to the nonwoven fabric manufacturing apparatus 10 through the pipe 22 . The supply of the solution 23 to the nonwoven fabric manufacturing apparatus 10 is performed by the pump 27 provided in the pipe 22 .

The nonwoven fabric manufacturing apparatus 10 forms nanofibers by the field spinning method, and manufactures a nonwoven fabric with this nanofiber. The nonwoven fabric manufacturing apparatus 10 includes a liquid outlet 30 for discharging the solution 23 . The liquid extraction unit 30 has five nozzles 31a to 31e (see FIG. 2 ) as described later, and only one of the nozzles 31a is illustrated in FIG. 1 . In the following description, when the nozzles 31a to 31e are not distinguished, they are described as the nozzles 31 . The solution preparation unit 21 described above is connected to one end (hereinafter referred to as a base end) 31P of the nozzle 31 of the nonwoven fabric manufacturing apparatus 10 , whereby the solution 23 is discharged from the nozzle. (31) is supplied. An opening (not shown) for discharging the solution 23 is formed at the other end (hereinafter referred to as a tip) 31D of the nozzle 31 , and the solution 23 is discharged from this opening.

The nonwoven fabric manufacturing apparatus 10 further includes a collecting unit 32 , a power source 33 , and a continuous member 71 . The collecting unit 32 includes a charging belt 37 , a rotating unit 38 , a supply unit 41 , and a winding unit 42 . The power supply 33 applies a voltage to the nozzle 31 of the liquid extraction unit 30 and the charging belt 37 of the collecting unit 32, thereby charging the nozzle 31 to the first polarity, and the charging belt 37 ) is charged with a second polarity opposite to the first polarity. The solution 23 is charged to the first polarity by passing through the charged nozzle 31, and discharged from the nozzle 31 in a charged state (liquid extraction step).

The charging belt 37 attracts the solution 23 discharged from the nozzle 31 and collects the formed nanofibers 12 as the nonwoven fabric 11 . In this example, the charging belt 37 collects the nanofibers 12 on the long collecting material 43 supplied from the supply unit 41 , so the collecting material 43 is connected to the charging belt 37 . Working together, they function as collectors. The charging belt 37 is a metal belt-shaped object and is an endless belt formed in an annular shape. The charging belt 37 may be formed of a material that is charged by applying a voltage from the power supply 33, and may be, for example, made of stainless steel. Although the collecting material 43 is made of a strip-shaped aluminum sheet in this embodiment, it is charged with the second polarity through the charging belt 37 and does not interfere with the attraction of the solution 23 by the charging belt 37 . As long as it is not, the material is not limited.

In this embodiment, the nozzle 31 is positively charged and the charging belt 37 is negatively charged. However, the polarities of the nozzle 31 and the charging belt 37 may be reversed. By these charging, a substantially conical taylor cone (not shown) composed of the solution 23 is formed at the tip 31D of the nozzle 31, and the solution 23 is discharged from the taylor cone as a spinning jet on a charging belt ( 37), it becomes the nanofiber 12. The nanofibers 12 form a nonwoven fabric on the collecting material 43 .

The distance L1 between the nozzle 31 and the collecting material 43 has an appropriate value depending on the kind of the nanofiber material 25 and the solvent 26 , the mass ratio of the solvent 26 in the solution 23 , and the like. , in the range of 100 mm or more and 300 mm or less is preferable, and it is set as 150 mm in this embodiment.

The rotating part 38 is comprised by a pair of rollers 46 and 47, the motor 48, etc. The charging belt 37 is horizontally spanned by a pair of rollers 46 and 47 . A motor 48 disposed outside the spinning chamber 51 is connected to the shaft of one roller 46, and rotates the roller 46 at a predetermined speed. By this rotation, the charging belt 37 moves in the longitudinal direction so as to circulate between the rollers 46 and 47 . In the present embodiment, the moving speed of the charging belt 37 is 10 cm/hour, but it is not limited thereto.

The supply unit 41 has a delivery shaft 41a. A collection material roll 52 is set on the delivery shaft 41a. The collecting material roll 52 has a structure in which the collecting material 43 is wound around the winding core 53 . The winding portion 42 has a winding shaft 56 . The winding shaft 56 is rotated by a motor (not shown), whereby the collecting material 43 moves in the longitudinal direction, and the nonwoven fabric 11 is attached to the winding core 57 set on the winding shaft 56 . The collecting material 43 in the formed state is wound up. By continuously discharging the solution 23 from the nozzle 31 toward the moving collecting material 43, the nanofibers 12 are collected on the collecting material 43, and the nonwoven fabric 11 is continuously produced. (collection process). The elongate nonwoven fabric 11 obtained by continuously manufacturing is peeled off from the collection material 43, cut to the size and shape according to a use, and is provided for use.

In this example, the rotation speed of the winding shaft 56 and the rotation speed of the roller 46 are made the same, and the collection material 43 is moved by the rotation of the winding shaft 56, but the collection material 43 may be placed on the charging belt 37 and moved by the movement of the charging belt 37 .

The nanofibers 12 may be directly collected on the charging belt 37 without using the collecting material 43 . In this case, the charging belt 37 functions as a collector. However, depending on the material forming the charging belt 37 or the surface condition of the charging belt 37, the nonwoven fabric 11 may adhere and be difficult to peel. For this reason, as in the present embodiment, guiding the collecting material 43 to which the nonwoven fabric 11 is difficult to adhere is guided onto the charging belt 37, and collecting the nanofibers 12 on the collecting material 43 is desirable.

The liquid extraction unit 30 includes a nozzle 31 , a conduction member 61 , and a container 62 . The nozzle 31 is provided in the container 62 in the attitude|position which made the front-end|tip 31D upward. That is, the nozzle 31 is in a state where the tip 31D from which the solution 23 is discharged faces the charging belt 37 disposed above the nozzle 31 .

The container 62 contains the solvent 63 which dissolves the nanofiber material 25 . This solvent 63 is a liquid. When the solvent 63 is vaporized, the tip 31D is disposed in an atmosphere containing the solvent 63 in a gaseous state. This gaseous solvent is hereinafter referred to as solvent gas 66 . However, in this example, although the nozzle 31 is attached to the bottom part of the container 62 in a penetrating state, the method of attaching the nozzle 31 to the container 62 is not limited to this. For example, by connecting the base end 31P of the nozzle 31 to a tube (not shown) penetrating the bottom of the container 62 , the nozzle 31 may be attached to the container 62 through the tube. In addition, the solvent 63 should just melt|dissolve the nanofiber material 25. FIG. Examples of the solvent 63 include the same solvent as that of the solvent 26 .

Because the tip 31D of the nozzle 31 is upward, even when the solution 23 is agglomerated at the tip 31D, the agglomerate falls on the nanofibers 12 accumulated on the charging belt 37. there is no case In addition, by disposing the tip 31D in an atmosphere containing the solvent 63 , adhesion of the lump to the tip 31D is suppressed, and clogging of the tip 31D is prevented. As a result of these, the nanofibers 12 are manufactured with good yield and efficiently.

A pipe 22 for guiding the solvent 63 sent from the pump 27 is connected to the container 62 . The container 62 is provided with a liquid level sensor 67 that detects the level of the liquid level 63s of the solvent 63, based on the detection signal of the liquid level sensor 67, the container 62 of the solvent 63. The injection amount is controlled, and the height of the liquid level 63s is adjusted. The height of the liquid level 63s is lower than the height of the tip 31D of the nozzle 31 disposed in the container 62 . That is, the nozzle 31 is provided in the container 62 with the tip 31D taken out from the liquid level 63s. Thereby, by the solvent gas 66, the front-end|tip 31D is put in the atmosphere containing the solvent 63, and clogging of the front-end|tip 31D is prevented more reliably.

It is preferable that the distance from the liquid level 63s of the front-end|tip 31D exists in the range of 2 mm or more and 15 mm or less, and it is set as 5 mm in embodiment. Compared to the case of less than 2 mm by being 2 mm or more, the liquid solvent 63 does not rise to the tip 31D of the nozzle 31, so it is emitted more stably, and when it is 5 mm or less, compared to the case of greater than 15 mm, solvent gas Since the solution 23 is discharged from the nozzle 31 in a high-concentration atmosphere, it is emitted more stably.

Moreover, the container 62 is provided with the temperature sensor 68 which detects the temperature of the solvent 63, Based on the detection signal of this temperature sensor 68, the solvent (not shown) by a temperature control part (not shown) 63) is controlled. It is preferable that the temperature of the solvent 63 is 5 degreeC or more lower than the boiling point of the solvent 63, ie, it is at least 5 degreeC lower than the boiling point of the solvent 63, and it is made 5 degreeC low in this embodiment. In addition, the container 62 and the solvent 63 do not necessarily need to be used.

The conduction member 61 is disposed below the container 62 . The conduction member 61 is electrically connected to the base end 31P side of the nozzle 31 protruding below the container 62 . The power supply 33 is connected to the conduction member 61 , and applies a voltage to the nozzle 31 via the conduction member 61 . In addition, the method of applying a voltage to the nozzle 31 is not limited to this. For example, a voltage may be applied to the nozzle 31 by connecting the power supply 33 to the nozzle 31 . The voltage to be applied is preferably 2 kV or more and 40 kV or less, and from the viewpoint of forming the nanofibers 12 thin, the voltage is preferably as high as possible within this range. In this embodiment, the voltage to be applied is set to 30 kV.

In this example, the nozzle 31 is provided in a posture with the tip 31D facing upward, and the charging belt 37 is disposed above the nozzle 31 . However, the posture of the nozzle 31 and the nozzle 31 ) and the charging belt 37 are not limited to this embodiment. For example, the nozzle 31 may be provided in a posture with the tip 31D facing down, and the charging belt 37 may be disposed below the nozzle 31. In this case, the container 62 and the solvent ( 63) is not used.

Between the liquid extraction unit 30 and the conveying path of the collecting material 43 on the charging belt 37 , a continuous member 71 extending from the nozzle 31 side toward the collecting material 43 and the charging belt 37 . is provided. The continuous member 71 is a plate-shaped member disposed along the longitudinal direction of the charging belt 37 and the collecting material 43 . The continuous member 71 is provided in an upright position with respect to the belt surface of the charging belt 37 on the nozzle 31 side and the collecting material 43 on the charging belt 37 . The continuous member 71 is connected to the power supply 33 in parallel with the nozzle 31 . Details of the speech member 71 will be described later with reference to other drawings.

The above-mentioned spinning chamber 51 accommodates, for example, a portion of the liquid extraction unit 30 and the collection unit 32 , and the extension member 71 . In the spinning chamber 51, the nozzle 31 and the container 62 are arranged at the lower part, and the collecting part 32 is arranged at the upper part. The spinning chamber 51 is configured to be hermetically sealed, thereby preventing the solvent gas or the like from leaking to the outside. The solvent gas is a vaporized solvent 26 of the solution 23 .

As shown in FIG. 2 , the nozzles 31a to 31e are arranged in a spaced apart state from each other in the width direction of the charging belt 37 . In addition, since the width direction of the collecting material 43 and the width direction of the charging belt 37 coincide, in the following description, these are collectively called "width direction" simply. In addition, "arranged in the width direction" means that, when they are arranged with components in the width direction, they may be arranged at a position slightly shifted in the longitudinal direction of the charging belt 37 and the collecting material 43 . In this embodiment, when all of the nozzles 31a-31e are located in the range of 50 mm in the longitudinal direction, it allows as an aspect arranged in the width direction. Among the nozzles 31a to 31e arranged in order in the width direction, the nozzle disposed at the outermost side in the width direction is called an outermost nozzle. The outermost nozzles in this example are the nozzle 31a and the nozzle 31e.

In this example, although the number of the nozzles 31 is made into five, the number of the nozzles 31 is not limited to five, What is necessary is just two or more. In addition, in this example, the opening for discharging the solution 23 is arranged in the width direction by arranging the plurality of nozzles 31 in the width direction. A member may be used instead of the plurality of nozzles 31 .

When the distance between the openings at the tip 31D is L2, the distance L2 is 1 mm or more, compared with the case where it is less than 1 mm, the discharge between the nozzles 31 is suppressed, so that the emission is more stably, and the distance L2 is 20 mm or less As a result, the device can be further miniaturized as compared with the case larger than 20 mm. It is more preferable that the distance L2 exists in the range of 3 mm or more and 10 mm or less, and it is set as 5 mm in this embodiment. In addition, the distance L2 between openings is a distance between the centers of mutually adjacent openings.

An angle θ of the nozzle 31 with respect to the liquid level 63s will be described. Here, θ when the longitudinal direction of the nozzle 31 is horizontal is 0°, and θ when vertically upward is 90°. Since the nozzle 31 is upward, 0°<θ≤90°. The closer this angle θ is to 90°, the smaller the voltage required to move the solution 23 discharged from the nozzle 31 to the charging belt 37 . As the voltage applied to the nozzle 31 is small, vaporization of the solvent 26 at the tip 31D is suppressed, and clogging of the nozzle 31 is further suppressed. For this reason, it is preferable that the angle (theta) exists in the range of 45 degrees or more and 90 degrees or less, and the angle (theta) is 90 degrees in this embodiment.

It is more preferable that the tips 31D of the plurality of nozzles 31a to 31e are in the same direction. Thereby, the nonwoven fabric 11 with a more uniform weight, ie, a more uniform thickness, is obtained. The weight is the mass per unit area of the nonwoven fabric.

The continuous member 71 is for drawing the position where the nanofiber 12 formed by the solution discharged|emitted from the outermost nozzle is collected by the collecting material 43 inward in the width direction. As described above, since the continuous member 71 is connected to the power supply 33 in parallel with the nozzle 31, the width direction inner surface 71s is charged with the first polarity of the same polarity as that of the nozzle 31a. are doing In this embodiment, since the nozzle 31 is positively charged, the polarity of the extending member 71 is also positive. When the nozzle is negatively charged, the polarity of the extended member 71 becomes negative (-). Although the continuous member 71 is formed in a plate shape as described above, it is not limited to a plate shape, and may be formed, for example, in a block shape. Even when formed in block shape, the surface 71s of the width direction inner side should just be charged with the same polarity as the nozzle 31a. The one extended member 71 is arrange|positioned outside the nozzle 31a which is one of a pair of outermost nozzles, and is provided in the state away from the nozzle 31a with a space|interval. The extended member 71 is similarly provided also on the side of the nozzle 31e, which is the other of the pair of outermost nozzles, and this extended member 71 is similarly connected to the power supply 33 and the nozzle 31 in parallel. Therefore, the surface 71s of the width direction inner side is charged with the 1st polarity of the same polarity as the nozzle 31e.

Since the extending member 71 is provided in a state away from the respective tips 31D of the nozzles 31a and 31e, the transfer of electric charges from the nozzles 31a and 31e to the extending member 71 This is prevented. For this reason, the polarity between the surface 71s of the charged continuous member 71 and the nozzle 31 is maintained, and the solution 23 is stably discharged from the nozzle 31a and the nozzle 31e. Since the surface 71s of the continuous member 71 is charged with the same polarity as that of the nozzle 31a and the nozzle 31e, the continuous member 71 is discharged from the opening of the tip 31D of each of the nozzle 31a and the nozzle 31e. It is also the same polarity as the solution 23, and for this reason, the solution 23 directed from the nozzle 31a and the nozzle 31e to the collecting material 43 is electrically repelled with the surface 71s, so the width direction is drawn inward. As a result, the formed nanofibers 12 are drawn inward in the width direction at a position where they are collected by the collecting material 43 compared with the case where the extending member 71 is not provided. Therefore, in the nonwoven fabric 11, thickness is suppressed from thinning in the both sides part mainly formed by the nozzle 31a and the solution 23 discharged|emitted from the nozzle 31e, and peeling from the collecting material 43 in a post process. When it does, peeling residue is suppressed.

The continuous member 71 may be formed of an insulating material or may be formed of an electrically-conductive material. In the present embodiment, a ^{material having a volume resistivity of 10 7} Ω·cm or more is regarded as an insulating material, and a material having a volume resistivity of 10 ⁴ Ω·cm or less is regarded as a conductive material. In this embodiment, the volume resistivity is calculated|required by measuring by the double ring electrode method of Japanese Industrial Standards JIS K6911.

As an insulating material in the case where the continuous member 71 is formed of an insulating material, for example, an acrylic resin or a fluororesin is preferable from the viewpoint of reliably charging the nozzle 31 with the same polarity. In addition, it is preferable to select the insulating material from a material having resistance to the solvent 26 .

In this embodiment, since the nozzle 31 and the common power supply are used, the enlargement of an apparatus is suppressed. In addition, since the continuous member 71 only needs to have an amount of charge that attracts only the nozzle 31a and the solution 23 discharged from the nozzle 31e in the width direction among the plurality of nozzles 31a to 31e, It is not necessary to use a power source different from the power source 33 , and voltage application in parallel connection with the nozzle 31 is sufficient.

The distance L3 between the nozzle 31a or the tip 31D of the nozzle 31e and the extending member 71 is at least 5 mm, that is, preferably 5 mm or more, more preferably 5 mm or more and 50 mm or less, more preferably 10 mm or more and 40 mm It is more preferable to exist in the following range, and it is especially preferable to exist in the range of 15 mm or more and 30 mm or less.

The continuous member 71 may extend from the nozzle 31 side toward the charging belt 37 and the collecting material 43 . That is, the extending direction should just have the component of the perpendicular direction in FIG. For example, the continuous member 71 may extend in the vertical direction in FIG. 2 , or may extend in a direction intersecting the vertical direction as in the present example shown in FIG. 2 . In this example, the surface 71s becomes closer to the center in the width direction as it goes from the tip 31D of the nozzle 31a and the nozzle 31e toward the charging belt 37 and the collecting material 43. Thus, the speech member 71 is provided. That is, the distance between the pair of continuous members 71 gradually decreases as they move toward the charging belt 37 and the collecting material 43 . Thereby, the position collected by the collecting material 43 of the nanofiber 12 is drawn inward in the width direction more reliably.

It is preferable that the continuous member 71 extends to a position as close as possible to the extent that it does not come into contact with the moving charging belt 37 and the collecting material 43 . That is, the distance L4 between the continuous member 71 and the collecting material 43 is preferably set as small as possible to such an extent that it does not come into contact with the moving collecting material 43 . In addition, since the continuous member 71 is for attracting the position where the nanofibers 12 formed by the solution from the nozzle 31a and the nozzle 31e are collected in the width direction, the surface 71s It is preferable that the end of the collecting material 43 side is disposed in a state located in the width direction than the side edge of the collecting material 43 .

The nanofiber material 25 is a polymer and is preferably any one of cellulose acylate, nitrocellulose, ethylcellulose, and carboxymethylethylcellulose. As cellulose acylate, cellulose triacetate, cellulose diacetate, cellulose propionate, cellulose butylate, and cellulose acetate propionate are more preferable.

As the solvent 26, methanol, ethanol, isopropanol, butanol, benzyl alcohol, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl formate, ethyl formate, hexane, Cyclohexane, dichloromethane, chloroform, carbon tetrachloride, benzene, toluene, xylene, dimethylformamide, N-methylpyrrolidone, diethyl ether, dioxane, tetrahydrofuran, 1-methoxy -2-propanol and the like. These may be used individually or in mixture, depending on the kind of nanofiber material 25, and may be used. Among these, dichloromethane (boiling point is 40 degreeC) is more preferable, and dichloromethane is used as the solvent 26 in this embodiment.

The nonwoven fabric manufacturing apparatus 80 shown in FIG. 3 is provided with the extended member 81 instead of the extended member 71 of the nonwoven fabric manufacturing apparatus 10. As shown in FIG. The power supply 33 is connected only to the roller 47 and the conduction member 61 . In this example, as in the above example, voltage is applied in a state in which the conducting member 61 is charged to positive (+) and the roller 47 to negative (-), so that the polarity of the nozzle 31 is positive (+). The polarities of +), the charging belt 37 and the collecting material 43 are negative (-). However, the voltage may be applied in a state in which the conducting member 61 is charged to negative (-) and the roller 47 to positive (+). As shown in FIG. 4 , the pair of continuous members 81 are each formed in a plate shape bent in an L shape, and one end of the nozzle 31a side and the nozzle 31e side is in contact with the conduction member 61 . placed in state. As a result, the extended member 81 is electrically connected to the nozzle 31a and the nozzle 31e. For this reason, the extended member 81 has an inner surface 81s of the nozzle 31a in the width direction. ) and the nozzle 31e are charged with the same polarity. In addition, since the continuous member only needs to be electrically connected to the nozzle 31a and the nozzle 31e in order to be charged with the same polarity as the nozzle 31a and the nozzle 31e, it is not limited to the L-shape as in this example. does not For example, even in the embodiment in which a flat plate-shaped extension member 71 is used and the extension member 71 is connected to the conduction member 61 with a conductive member such as a conducting wire, the nozzle 31a and the nozzle 31e It is good because it is electrically connected to

The extended member 81 also extends toward the charging belt 37 and the collecting material 43, similarly to the extended member 71, and is disposed away from the nozzle 31a and the tip 31D of the nozzle 31e. there is. For this reason, the nanofiber 12 formed by the solution from the nozzle 31a and the nozzle 31e is pulled in the width direction inside, and is collected by the collecting material 43. In the same manner as the extended member 71 , the extended member 81 also has a surface 81s extending from the nozzle 31a and the tip 31D of the nozzle 31e to the charging belt 37 and the collecting material 43 . It is provided in the state used as the center vicinity in the width direction as it goes. Thereby, the position collected by the collecting material 43 of the nanofiber 12 is drawn inward in the width direction more reliably.

Example

[Example 1] to [Example 10]

The long nonwoven fabric 11 was manufactured using the nonwoven fabric manufacturing apparatus 80, and it was set as Examples 1-10. In Examples 1 to 10, as shown in Table 1, the distance L3 between the raw material of the extended member 81 and/or the distance L3 between the extended member 81 and the nozzle 31a and the tip 31D of the nozzle 31e. different from each other The nanofiber material 25 was cellulose triacetate. As the solvent 26, dichloromethane was used.

When an acrylic resin as an insulating material is used as the material of the continuous member 81, "acrylic" is described in the "Material" column of Table 1, and "SUS" when SUS (stainless steel) is used as the conductive material. Write it down. Since the nozzle 31 is positively charged as described above, the polarity of the surface 81s of the continuous member 81 is also positive. The column "polarity" in Table 1 indicates the polarity of the surface 81s of the continuous member 81 .

In each Example, the following evaluation method and reference|standard evaluated the spinning stability spun to the nanofiber 12 and the thickness of the side part in the obtained nonwoven fabric 11. As shown in FIG. Each evaluation result is shown in Table 1.

(1) Radiation stability

The emission state from the nozzle 31a and the nozzle 31e which are outermost nozzles were visually confirmed, and the following reference|standard evaluated. A and B are a pass level as what can manufacture the nonwoven fabric 11 more elongately, and C is a rejection.

A; The continuous emission time was more than 5 minutes

B; The time that could be emitted continuously was 1 minute or more and less than 5 minutes

C; The continuous emission time was less than 1 minute

(2) thickness of the side

A vertical line is drawn from the opening of the nozzle 31a, which is the outermost nozzle, to the collecting material 43, and the area from the vertical line in the collecting material 43 to a position of 10 mm toward the side edge side of the nonwoven fabric 11 The weight X was obtained. This weight X was calculated|required by measuring the sample weight of 1 cm x 1 cm with an electronic balance. Moreover, a vertical line is drawn from each opening of the nozzles 31a, 31e to the collecting material 43, and in each of the five places in the area|region enclosed between the vertical lines in the collecting material 43, 1 cm x 1 cm Five samples were obtained by sampling to the size of . The weight of each of these samples was measured with an electronic balance, and the average value Y of the weight was calculated|required. And the weight ratio (unit is %) calculated by (X/Y)*100 was calculated|required, and this weight ratio was evaluated as the thickness of a side part. A and B are pass and C is fail.

A; The weight ratio was more than 90%

B; The weight ratio was 80% or more and less than 90%

C; The weight ratio was less than 80%

[Table 1]

[Comparative Example 1] to [Comparative Example 3]

By separating the continuous member 81 from the nonwoven fabric manufacturing apparatus 80, a nonwoven fabric was manufactured without using the continuous member 81, and this case was set as Comparative Example 1. Other conditions of Comparative Example 1 were the same as in Example. Since the nonwoven fabric manufacturing apparatus used in Comparative Example 1 does not have the speech member 81, the "Material", "Polarity", and "Distance L3" columns of the "Speed member" column of Table 1 are all blank. Moreover, the continuous member 81 of the nonwoven fabric manufacturing apparatus 80 was replaced with the continuous member 70, and it was set as the comparative examples 2 and 3. The continuous member 70 in Comparative Examples 2 and 3 is not connected in parallel with the nozzle 31 with respect to the power supply 33, but is brought into contact with the nozzle 31a and the tip 31D of the nozzle 31e. (31a) and the nozzle (31e) and the positive (+) of the same polarity was charged. Since the continuous member 71 and the tip 31D are brought into contact, the distance L3 is 0 (zero) mm as shown in Table 1.

In each comparative example, the radiation stability and the thickness of the side part were evaluated by the same method and reference|standard as that of an Example. Each evaluation result is shown in Table 1. In Comparative Examples 2 and 3, the solution 23 was not discharged from the nozzles 31a and 31e.

10, 80 Non-woven fabric manufacturing equipment
11 Non-woven
12 nanofiber
21 solution preparation section
22 plumbing
23 solution
25 nanofiber materials
26 solvent
27 pump
30 withdrawals
31a~31e Nozzle
31D tip
31P Air Force
32 collection unit
33 power
37 Daejeon Belt
38 rotating part
41 supply
41a transmission shaft
42 winding
43 collection material
46, 47 rollers
48 motor
51 spinning room
52 Collector Roll
53 winding core
56 take-up shaft
57 winding core
61 Conduction member
62 courage
63 solvent
66 solvent gas
67 Liquid level sensor
68 temperature sensor
71, 81 Absence of speech
71s. The inner surface in the 81s width direction
Distance between L1 nozzle and collecting material
Distance between L2 openings
Distance between the tip of the L3 outermost nozzle and the speech member
Distance between L4 speech member and trapping material
θ Nozzle angle

Claims (8)

In a state in which a voltage is applied between a collector and a plurality of nozzles, a solution in which a nanofiber material is dissolved in a solvent is discharged from each of the plurality of nozzles toward the collector, thereby manufacturing a nonwoven fabric formed of nanofibers In the method,
a liquid extraction step of discharging the solution from each tip of the plurality of nozzles arranged in the width direction of the long collector moving in the longitudinal direction;
and a collecting process of collecting the solution discharged from the nozzle as the nonwoven fabric in the collector,
It is provided outside the outermost nozzle in the width direction among the plurality of nozzles in a state away from the tip of the outermost nozzle, extends toward the collector, and is charged with the same polarity as the plurality of nozzles. an end edge in the width direction of the solution facing the collector is pulled inward in the width direction of the collector by the continuous member,
electrically connecting the nozzle and the extended member, or by connecting the nozzle and the extended member in parallel to a power source for applying the voltage, to charge the flexible member with the same polarity as the plurality of nozzles;
The surface of the inner side of the continuous member in the width direction of the collector becomes closer to the center of the collector in the width direction from the outermost nozzle toward the collector. delete The method according to claim 1,
The distance between the continuous member and the tip of the outermost nozzle is 5 mm or more. delete 4. The method according to claim 1 or 3,
The nonwoven fabric manufacturing method in which the said continuous member is formed from an acrylic resin or a fluororesin. 4. The method according to claim 1 or 3,
The nanofiber material is at least any one of cellulose triacetate, cellulose diacetate, cellulose propionate, cellulose butylate, cellulose acetate propionate, nitrocellulose, ethyl cellulose, and carboxymethyl ethyl cellulose. A method for manufacturing a non-woven fabric. In a state in which a voltage is applied between a collector and a plurality of nozzles, from the tip of each of the plurality of nozzles toward the collector, a solution in which the nanofiber material is dissolved in a solvent is discharged, thereby producing a nonwoven fabric formed of nanofibers In the nonwoven fabric manufacturing apparatus,
the long collector moving in the longitudinal direction;
the plurality of nozzles arranged in the width direction of the collector;
a power supply for applying the voltage between the nozzle and the collector;
It is provided outside the outermost nozzle in the width direction among the plurality of nozzles in a state away from the outermost nozzle, extends toward the collector, and is charged with the same polarity as the plurality of nozzles. having an absence,
The continuous member is electrically connected to the nozzles or by being connected in parallel with the nozzles to the power source to have the same polarity as the plurality of nozzles;
The nonwoven fabric manufacturing apparatus is such that the inner surface of the continuous member in the width direction of the collector becomes closer to the center of the collector in the width direction from the outermost nozzle toward the collector. delete

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