Nozzle head and spinning device

Abstract

To provide a nozzle head and a spinning device, which can stabilize basis weight of a fiber assembly to be formed.SOLUTION: A nozzle head 20 has a cylindrical solution tank 30 having a plurality of spinning holes 36 to fill the inside with a spinning solution 31 and inject the spinning solution 31, and a spinning electrode 50 that is disposed in the solution tank 30 in a state of contacting the spinning solution 31. The solution tank 30 has an outer pipe 33 on which the plurality of spinning holes 36 is formed along an axis line L1, and an inner pipe 32 that is disposed in the outer pipe 33 and feeds the spinning solution 31 into a storage space 35 formed between the inner pipe and the outer pipe 33. The inner pipe 32 has a plurality of inner holes 37 to discharge the spinning solution 31 into the storage space 35. The inner holes 37 and the spinning holes 36 are disposed so that the spinning solution 31 discharged from at least one of the inner holes 37 is discharged toward a region of the outer pipe 33 at which the spinning hole 36 is not formed.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a nozzle head and a spinning device. [Background technology]

[0002] The device disclosed in Patent Document 1 is a device that spins ultrafine fibers from a spinning solution by electrospinning to form a fiber aggregate. This device is equipped with a storage tank and a spinning electrode as a nozzle head. The storage tank is cylindrical and stores the spinning solution inside. The storage tank has a plurality of spinning holes formed along the axis. The spinning electrode is placed inside the storage tank while being immersed in the spinning solution. The spinning solution inside the storage tank is charged by a high voltage applied between the spinning electrode and a collector electrode placed outside the storage tank. The charged spinning solution is sprayed from the spinning hole toward the collector electrode by the action of electrostatic force to become fibers. This device forms a fiber aggregate by collecting the fibers generated in this way with a collecting member and depositing them. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-084387 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of Patent Document 1, the amount of spinning solution injected from each spinning hole is not uniform, which may cause unevenness in the basis weight of the formed fiber aggregate.

[0005] An object of the present disclosure is to provide a nozzle head and a spinning device that can stabilize the basis weight of the formed fiber aggregate. [Means for solving the problem]

[0006] The nozzle head according to an embodiment of the present disclosure is a cylindrical solution tank filled with a spinning solution therein and having a plurality of spinning holes for injecting the spinning solution, and a spinning electrode disposed in the solution tank in contact with the spinning solution, and is a nozzle head comprising the solution tank includes an outer tube provided with a plurality of the spinning holes along an axis, and an inner tube disposed within the outer tube and supplying the spinning solution into a storage space formed therebetween. The inner tube has a plurality of inner holes for discharging the spinning solution into the storage space, the inner holes and the spinning holes are arranged such that the spinning solution discharged from at least one of the inner holes is discharged toward a region of the outer tube where no spinning hole is formed.

[0007] A spinning device according to an embodiment of the present disclosure includes the above nozzle head and a collector electrode disposed away from the spinning electrode, and includes by applying a voltage between the spinning electrode and the collector electrode, a jet of the charged spinning solution is injected toward the collector electrode and formed into fibers, and is collected as a fiber aggregate by a collecting member disposed along a surface of the collector electrode on the side of the spinning electrode.

Advantages of the Invention

[0008] According to the present disclosure, the inner holes and the spinning holes are arranged in such a manner that the spinning solution discharged from at least one of the inner holes is discharged toward the region of the outer tube where the spinning holes are not formed. That is, the spinning solution discharged from the inner holes is discharged in a direction different from the direction of the spinning holes. Therefore, compared with the case where the spinning solution is discharged directly from the inner holes toward the region where the spinning holes are formed, the spinning solution flows through the storage space over a longer distance. As a result, even if there is a difference in the discharge amount of the spinning solution discharged from each inner hole, the difference can be mitigated while flowing through the storage space, and the amount of the spinning solution sprayed from each spinning hole can be made uniform. Therefore, the nozzle head and spinning device according to the present disclosure can stabilize the basis weight in the fiber aggregate to be formed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of an electrospinning device according to the first embodiment. [Diagram 2] FIG. 2 is a partial configuration diagram of the spinning apparatus as seen from a different direction than that of FIG. [Diagram 3] FIG. 3 is a plan view showing the nozzle head with a portion thereof omitted. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA of FIG. [Diagram 5] FIG. 5 is an enlarged view of a cross section taken along the line BB in FIG. [Figure 6] FIG. 6 is a schematic diagram showing the outer tube and the inner tube used in the experiment. [Figure 7] FIG. 7 is a graph showing the experimental results. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A preferred embodiment of the present disclosure will be described.

[0011] In the nozzle head according to the present disclosure, the inner hole and the radiating hole can be arranged in such a manner that, when viewed from the direction of the axis, the first discharge direction of the spinning solution discharged from at least one of the inner holes and the second discharge direction of the spinning solution discharged from at least one of the radiating holes are at different angular positions on the circumference around the axis. That is, the inner hole can be provided at a position shifted circumferentially around the axis from the position of the radiating hole with respect to the radiating hole. In this case, the spinning solution flows through the storage space over a longer distance by the amount of position shift, compared to when the first discharge direction and the second discharge direction are the same, that is, when the inner hole is provided at the same circumferential position around the axis with respect to the position of the radiating hole. As a result, even if there is a difference in the discharge amount of the spinning solution discharged from each inner hole, the difference can be mitigated while flowing through the storage space, and the amount of the spinning solution sprayed from each radiating hole can be further uniformed.

[0012] In the nozzle head according to the present disclosure, the inner hole and the radiating hole may be arranged in such a manner that the first discharge direction and the second discharge direction are separated by a gap of 90° or more and 270° or less on the circumference around the axis. That is, when the solution tank is viewed from a direction perpendicular to the plane including the axis and the radiating hole, the inner hole may be provided on the opposite side of the axis from the position of the radiating hole. In this case, the spinning solution discharged from the inner hole can be circulated in the storage space in the circumferential direction around the axis for a longer distance to reach the radiating hole. Therefore, even if there is a difference in the discharge amount of the spinning solution discharged from each inner hole, the difference can be mitigated while flowing through the storage space, and the amount of the spinning solution sprayed from each radiating hole can be further uniformed.

[0013] In the nozzle head according to the present disclosure, the inner hole and the radiation hole can be arranged in such a manner that the first discharge direction and the second discharge direction are at positions 180° opposite to each other on the circumference around the axis. That is, the inner hole can be provided in the plane. In this case, the spinning solution discharged from the inner hole can be circulated over a longer distance in the circumferential direction around the axis in the storage space to reach the radiation hole, and the discharge amount of the spinning solution sprayed from each radiation hole can be made even more uniform.

[0014] In the nozzle head according to the present disclosure, the axial position of each of the inner holes is shifted from the axial position of each of the radiation holes. That is, the inner holes can be provided at a position shifted from the position of each of the radiation holes in the axial direction with respect to the radiation holes. In this case, the spinning solution flows through the storage space over a longer distance by the amount of the shift, compared to when the axial position of the inner hole is the same as the axial position of the radiation hole, that is, when the inner hole is provided at the same axial position with respect to the radiation hole. As a result, even if there is a difference in the amount of spinning solution discharged from each inner hole, the difference can be mitigated while flowing through the storage space, and the amount of spinning solution sprayed from each radiation hole can be further uniformed.

[0015] <Embodiment 1> Hereinafter, a first embodiment of the nozzle head and spinning device according to the present disclosure will be described with reference to the drawings.

[0016] (Configuration of spinning device) 1 and 2 is configured as an electrospinning device. The spinning device 10 spins ultrafine fibers from a spinning solution 31, and continuously forms a fiber aggregate 14, such as a nonwoven fabric, made of the ultrafine fibers.

[0017] The spinning solution 31 is prepared by dissolving or dispersing a resin material that forms ultrafine fibers in a volatile solvent. As the solute, for example, synthetic resins such as polyacrylonitrile (PAN), polypropylene (PP), and polyethylene (PE) are used. As the solvent, for example, compounds such as N,N-dimethylacetamide (DMA), N,N-dimethylformamide (DMF), and tetrahydrofuran (THF) are used.

[0018] The spinning device 10 includes a nozzle head 20. The nozzle head 20 sprays the stored spinning solution 31 to the outside. The nozzle head 20 is cylindrical and elongated in one direction (the Y-axis direction in each drawing). The total length of the nozzle head 20 is, for example, 450 mm or more. The upper limit of the total length of the nozzle head 20 is not particularly limited, but is, for example, 1200 mm or less.

[0019] The nozzle head 20 has a plurality of spinning holes 36 formed at regular intervals along the longitudinal direction. The spinning holes 36 are holes for injecting the spinning solution 31 to the outside. The spinning holes 36 open to the side of the nozzle head 20. In each figure, the nozzle head 20 is shown diagrammatically with the dimensions of each part of the nozzle head 20 and the number of spinning holes 36 changed.

[0020] As shown in Fig. 3 to Fig. 5, the nozzle head 20 includes a solution tank 30 and a spinning electrode 50. The solution tank 30 is for storing the amount of spinning solution 31 required for spinning. The solution tank 30 is generally in the shape of a cylinder extending linearly along the central axis (axis L1). The solution tank 30 is disposed with the axis L1 aligned with the width direction of the collection member 11 (Y direction in each figure) (see Fig. 1, Fig. 2, etc.).

[0021] As shown in FIG. 3 to FIG. 5, the solution tank 30 has a double-tube structure including an inner tube 32 and an outer tube 33. The inner tube 32 and the outer tube 33 are formed of, for example, a solvent-resistant resin. The solvent-resistant resin is, for example, a synthetic resin such as fluororesin (PTFE). The inner tube 32 and the outer tube 33 are each a circular tube. The inner tube 32 and the outer tube 33 are arranged coaxially with the axis L1 of the solution tank 30. That is, the axis L1 of the solution tank 30 is also the axis of the inner tube 32 and the outer tube 33. The outer diameter of the outer tube 33 is, for example, 10 mm. The space between the outer peripheral surface of the inner tube 32 and the inner peripheral surface of the outer tube 33 is a storage space 35 in which the spinning solution 31 is stored. The spinning solution 31 in the storage space 35 is supplied through the inner tube 32 from a supply port 61 at the end in the direction of the axis L1. The storage space 35 functions as a buffer space for the spinning solution 31 discharged from an inner hole 37 of the inner tube 32, which will be described later.

[0022] The supply port 61 supplies the spinning solution 31 to the inside of the inner tube 32. The supply port 61 is provided at the end of the inner tube 32 as shown in FIG. 3 and FIG. 4. In the present embodiment, the supply port 61 is provided at both ends of the inner tube 32. Specifically, the supply port 61 is provided in a form in which both ends of the inner tube 32 protrude from both ends of the outer tube 33 and open toward both sides in the direction of the axis L1. Both ends of the outer tube 33 are closed by disk-shaped members having through holes 34. The supply ports 61 are connected to the pipes 42, respectively. In a state in which the supply ports 61 are connected to the pipes 42, the pipes 42 extend along the axis L1 from the connection portion with the nozzle head 20. The connection mode of the pipes 42 is not particularly limited, but the pipes 42 that deliver the spinning solution 31 in the same system or different systems are connected to one end side and the other end side in the direction of the axis L1.

[0023] As shown in FIG. 3 to FIG. 5, the outer tube 33 is provided with a radiation hole 36. The radiation hole 36 is circular in plan view. The diameter of the radiation hole 36 is preferably 0.5 mm-2.0 mm, for example, 1.0 mm. The radiation hole 36 is provided in the upper part of the outer tube 33. In detail, the radiation hole 36 is provided in the highest part (top) of the upper part of the outer tube 33. As a result, the radiation hole 36 sprays the spinning solution 31 vertically upward. That is, in this embodiment, the "second discharge direction" according to the present disclosure is vertically upward. A plurality of radiation holes 36 are provided along the axis L1. The plurality of radiation holes 36 are arranged in a row along the axis L1. The plurality of radiation holes 36 are provided at equal pitches of interval D along the axis L1. The interval D between adjacent radiation holes 36 is preferably 5 mm-20 mm, for example, 10 mm. The distance between adjacent radiation holes 36 is the distance between the centers of each radiation hole 36.

[0024] As shown in FIGS. 3 to 5, the inner tube 32 is provided with an inner hole 37. The inner hole 37 is circular in plan view. The inner hole 37 supplies the spinning liquid 31 to the storage space 35. The inner hole 37 discharges the spinning liquid 31 from the inside to the outside of the inner tube 32. The inner hole 37 discharges the spinning liquid 31 to an area where the spinning hole 36 is not formed. In other words, the inner hole 37 discharges the spinning liquid 31 into the storage space 35 in a direction different from the direction of the spinning hole 36. As shown in FIGS. 4 and 5, in this embodiment, the discharge direction of the spinning liquid 31 discharged from the inner hole 37 is a direction that is a different angular position on the circumference around the axis L1. That is, in this embodiment, the inner hole 37 is provided at a position shifted circumferentially around the axis L1 from the position of the spinning hole 36 with respect to the spinning hole 36.

[0025] Also, in the case of this embodiment, the inner hole 37 is arranged in such a manner that it discharges in a direction separated from the discharge direction of the spinning solution 31 discharged from the spinning holes 36 by an interval of 90° or more on the circumference around the axis L1. That is, when viewing the solution tank 30 from the orthogonal direction (the X-axis direction shown in each figure) of the virtual plane P which is a plane including the spinning holes 36 and the axis L1, the inner hole 37 is located on the opposite side of the spinning holes 36 across the axis L1. FIG. 4 shows a cross-section of the nozzle head 20 cut by the virtual plane P. As described above, in the case of this embodiment, the spinning holes 36 are provided at the top of the outer tube 33. Therefore, the virtual plane P in this embodiment is a plane parallel to the vertical direction. The inner hole 37 is provided below the axis L1 with respect to the spinning holes 36 provided above the axis L1. Further, in the case of this embodiment, the inner hole 37 is provided within the virtual plane P. In other words, the inner hole 37 is provided at the lowest part (bottom) of the lower part of the inner tube 32. Thereby, the inner hole 37 discharges the spinning solution 31 vertically downward. That is, in this embodiment, the "first discharge direction" according to the present disclosure is vertically downward.

[0026] A plurality of inner holes 37 are provided along the axis L1. In the case of this embodiment, as shown in FIG. 4, the plurality of inner holes 37 are provided at positions shifted in the direction of the axis L1 with respect to the plurality of spinning holes 36 respectively. In other words, each inner hole 37 is provided between the pitches of the plurality of spinning holes 36 in the direction of the axis L1. Specifically, each inner hole 37 is provided at the center between two adjacent spinning holes 36 among the plurality of spinning holes 36 arranged at equal pitches. In other words, each inner hole 37 is shifted in the direction of the axis L1 by a distance of half of the interval D (0.5D) from the position of the spinning hole 36 closest to each spinning hole 36. In the case of this embodiment, all of the plurality of inner holes 37 discharge the spinning solution 31 vertically downward.

[0027] The spinning electrode 50 is formed of a conductive material such as a metal. The spinning electrode 50 is, for example, a stainless steel wire. The wire diameter of the spinning electrode 50 is, for example, 0.9 mm. As shown in FIG. 4, the spinning electrode 50 is composed of a wire (wire-shaped member) having a diameter smaller than the inner diameter of the inner tube 32. The spinning electrode 50 is entirely immersed in the spinning solution 31 in the solution tank 30. That is, the entire outer surface of the spinning electrode 50 is in contact with the spinning solution 31 in the solution tank 30.

[0028] The spinning electrode 50 has a spiral shape (coil shape) extending along the axis L1 of the solution tank 30 in the solution tank 30. The spinning electrode 50 is wound in a circular shape when viewed from the axis L1 direction. The length of the spinning electrode 50 is longer than the length of the central axis of the solution tank 30 (the length along the axis L1 between both ends of the solution tank 30). Specifically, the length of the spinning electrode 50 is more than twice as long as the length of the central axis of the solution tank 30. The spinning electrode 50 has a curved shape (a shape having a part extending so as to intersect with the axis L1), so it is longer than the length of the central axis of the solution tank 30. The spinning electrode 50 configured in this manner can have a larger contact area with the spinning solution 31 than a configuration (straight-line configuration) having the same length as the central axis of the solution tank 30. Therefore, the efficiency of imparting charge from the spinning electrode 50 to the spinning solution 31 can be improved. Although not shown, the spinning electrode 50 is connected to a wire connected to a power source 44 via a through hole 34 provided at one end (the right end in FIG. 4) of the outer tube 33, for example.

[0029] The spinning electrode 50 extends along the inner circumferential surface of the outer tube 33. In this embodiment, the diameter of the spinning electrode 50 in the spiral shape is approximately the same as the diameter of the inner circumferential surface of the outer tube 33. The pitch of the spinning electrode in the spiral shape is 10 mm, which is equivalent to the pitch of the spinning hole 36. The spinning electrode 50 is positioned in the direction of the axis L1 so that a portion of each spinning hole 36 enters the inside of the spinning hole 36. As a result, a part of the spinning electrode 50 is exposed from each spinning hole 36. In this case, the spinning solution 31 in an electrically charged state is easily sprayed directly from the spinning hole 36. That is, the spinning solution 31 is easily sprayed to the outside in an electrically charged state.

[0030] In addition, in the case of this embodiment, the spinning electrode 50 is positioned in the axial line L1 direction and placed in the solution tank 30 so that a portion located vertically below each inner hole 37 is generated. In this case, the spinning solution 31 discharged vertically downward from the inner hole 37 into the storage space 35 collides with the spinning electrode 50 to promote diffusion. As a result, the difference in momentum of the spinning solution 31 discharged from each inner hole 37 is further alleviated. As described above, the inner hole 37 is located 180 ° away from the position of the spinning hole 36 in the circumferential direction around the axis L1, and is provided in the center between adjacent spinning holes 36 in the axis L1 direction. For this reason, the spinning electrode 50 having a spiral shape with a pitch of 10 mm is placed in the solution tank 30 so as to be exposed from each spinning hole 36, and a portion located vertically below each inner hole 37 is generated.

[0031] In addition to the nozzle head 20 having the above configuration, the spinning device 10 includes a collecting member 11, a collector electrode 17, a tank 41, a pump 43, and a power source 44, as shown in Figs. 1 and 2. The collector electrode 17 is disposed between the delivery roller 12 and the take-up roller 15, as shown in Fig. 1. The collector electrode 17 is formed of a conductive material such as a metal. The collector electrode 17 is formed in a flat plate shape extending in the width direction of the collecting member 11 (left and right direction in Fig. 2). The collector electrode 17 is in contact with or close to the upper surface of the collecting member 11. The collecting member 11 is disposed along the surface of the collector electrode 17 on the spinning electrode 50 (see Fig. 4) side (nozzle head 20 side).

[0032] The collection member 11 is in the form of a strip, and is disposed on the nozzle head 20 side of the collector electrode 17. In the collection member 11, the direction (X-axis direction in each drawing) perpendicular to the width direction (Y-axis direction in each drawing) is defined as the front-rear direction. The collection member 11 is formed of a flexible material, for example, a collection cloth such as a nonwoven fabric. The collection member 11 is wound around a delivery roller 12 to form a roll 13. The collection member 11 is horizontally positioned between the delivery roller 12 and a take-up roller 15, and the fiber aggregate 14 is layered on the lower surface. The collection member 11 with the fiber aggregate 14 layered thereon is taken up by the take-up roller 15 to form a roll 16. When the fiber aggregate 14 is used, the collection member 11 with the layered fiber aggregate 14 is pulled out from the roll 16, and the fiber aggregate 14 is peeled off from the collection member 11.

[0033] As shown in FIGS. 1 and 2, the spinning solution 31 is stored in the tank 41. The tank 41 and the solution tank 30 are connected by a pipe 42. The pump 43 is disposed in the middle of the pipe 42 and supplies the spinning solution 31 in the tank 41 to the solution tank 30. The pump 43 is, for example, a plunger pump, and is capable of adjusting the flow rate of the spinning solution 31. The pump 43 supplies the spinning solution 31 approximately evenly to the two supply ports 61 in the nozzle head 20. The power source 44 is composed of a DC power source. The positive electrode of the power source 44 is connected to the spinning electrode 50, and the negative electrode is connected to the collector electrode 17.

[0034] 1 and 2, in the spinning device 10, the nozzle head 20 is disposed so that the spinning hole 36 is located below the collector electrode 17. The nozzle head 20 is disposed below the collecting member 11 in a state in which it is parallel to the collecting member 11. The nozzle head 20 is disposed so that the axis L1 is parallel to the width direction of the collecting member 11.

[0035] (Method of manufacturing fiber assembly) Next, a method for producing the fiber aggregate 14 will be described with reference to Figures 1 and 2. When the spinning device 10 is operated, the collecting member 11 is sent from the delivery roller 12 to the take-up roller 15 at a constant speed while in contact with or close to the lower surface of the collector electrode 17. Then, the spinning solution 31 is applied to the spinning electrode 50. When the pump 43 is operated, the spinning solution 31 in the tank 41 is supplied into the inner tube 32 as shown by the arrow in Figure 4. The spinning solution 31 supplied from the inner hole 37 of the inner tube 32 to the storage space 35 flows from the inner hole 37 toward the spinning hole 36. As a result, the spinning solution 31 is uniformly applied to the spinning electrode 50.

[0036] Next, a voltage is applied between the spinning electrode 50 and the collector electrode 17. The spinning electrode 50 is a positive electrode, and the collector electrode 17 is a negative electrode, and a voltage is applied between the two electrodes from the power source 44. As a result, the entire spinning solution 31 in the solution tank 30 is positively charged. The spinning solution 31 is charged so that the charge distribution around the spinning electrode 50 is uniform in the circumferential direction.

[0037] Next, fibers are ejected from the spinning holes 36 of the solution tank 30. Charges are induced and accumulated on the surface of the spinning solution 31 exposed in the spinning holes 36. These charges repel each other, and the repulsive force opposes the surface tension of the spinning solution 31. The spinning solution 31 is attracted by an electrostatic force (Coulomb force) acting along the electric field lines toward the collector electrode 17. When the electrostatic force overcomes the surface tension of the spinning solution 31, the charged spinning solution 31 begins to eject from the multiple spinning holes 36. Then, jets 38 of the charged spinning solution 31 are ejected from the multiple spinning holes 36 simultaneously toward the collector electrode 17, respectively.

[0038] As described above, the nozzle head 20 is provided so that the inner hole 37 discharges the spinning solution 31 in a direction different from the direction of the radiation hole 36. Specifically, the multiple inner holes 37 are provided at the bottom so as to discharge the spinning solution 31 downwardly relative to the radiation hole 36 provided at the top so as to spray the spinning solution 31 upwardly, at a position shifted in the circumferential direction around the axis L1 relative to the position of the radiation hole 36. In addition, the multiple inner holes 37 are provided at a position shifted in the axis L1 direction from the position of the radiation hole 36, and are provided in the center between adjacent radiation holes 36. As a result, the nozzle head 20 reduces the bias in the amount of spinning solution 31 sprayed from each radiation hole 36.

[0039] Next, the fibers are split and collected by the collection member 11. Since the surface area of ​​each jet 38 is large compared to its volume, the solvent in the jet 38 evaporates efficiently. This evaporation also reduces the volume of the jet, increasing the charge density. This increases the repulsive force of the charged spinning solution 31, causing each jet 38 to split into even thinner jets. Through this process, ultrafine fibers are spun, and a fiber aggregate 14 made of ultrafine fibers is collected on the lower surface of the collection member 11.

[0040] (Operation of embodiment 1) Next, the operation of this embodiment will be described. In the nozzle head 20, the spinning solution 31 supplied from the inner tube 32 into the storage space 35 is discharged from the inner hole 37 in a direction different from the direction of the spinning hole 36. In contrast, for example, when the spinning solution discharged from the inner hole heads directly toward the spinning hole, the spinning solution sprayed from the spinning hole is easily affected by the pressure, speed, etc. of the spinning solution discharged from the inner hole. In contrast, in the nozzle head 20, the spinning solution 31 is discharged from each inner hole 37 in a direction different from the direction of each spinning hole 36. For this reason, the spinning solution 31 discharged from the inner hole 37 flows through the storage space 35 for a longer distance. In addition, the spinning solution 31 discharged in a direction different from the direction of the spinning hole 36 collides with the inner wall surface of the outer tube 33 and the spinning electrode 50. That is, the spinning solution 31 is discharged from the inner hole 37 into an area where the spinning hole 36 is not formed. Therefore, each spinning hole 36 is less likely to be directly affected by the pressure difference, speed difference, etc. of the spinning solution 31 discharged from each inner hole 37.

[0041] In addition, in the present embodiment, the inner hole 37 is provided at a position shifted from the position of the radiation hole 36 in the circumferential direction around the axis L1 with respect to the radiation hole 36. Such an inner hole 37 is located farther away from the radiation hole 36 than an inner hole provided at the same position as the position of the radiation hole in the circumferential direction around the axis. Therefore, the influence of the pressure difference, speed difference, etc. of the spinning liquid 31 discharged from the inner hole 37 is further mitigated. In addition, the spinning liquid 31 discharged from such an inner hole 37 flows through the storage space 35 for a longer distance to reach the radiation hole 36. Therefore, the variation in the amount of the spinning liquid 31 sprayed to the outside from each radiation hole 36 is suppressed.

[0042] In addition, in the case of this embodiment, when the solution tank 30 is viewed from the orthogonal direction of the imaginary plane P including the axis L1 and the radiation hole 36, the inner hole 37 is provided on the opposite side of the axis L1 from the position of the radiation hole 36, that is, at a position shifted by 90° or more in the circumferential direction around the axis L1 with respect to the radiation hole 36. Therefore, the influence of the pressure difference, speed difference, etc. of the spinning solution 31 discharged from the inner hole 37 is further mitigated. In addition, since the spinning solution 31 discharged from such an inner hole 37 flows through the storage space 35 for a longer distance to reach the radiation hole 36, the variation in the amount of the spinning solution 31 sprayed to the outside from each radiation hole 36 is suppressed.

[0043] In addition, in the present embodiment, the inner hole 37 is provided in a virtual plane P including the axis L1 and the radiation hole 36. That is, the inner hole 37 is provided at a position shifted 180° from the position of the radiation hole 36 in the circumferential direction around the axis L1 with respect to the radiation hole 36. Therefore, the inner hole 37 is located farther away from the radiation hole 36 than when it is provided at the same position in the circumferential direction around the axis L1 from the position of the radiation hole 36. Therefore, the influence of the pressure difference, speed difference, etc. of the spinning liquid 31 discharged from the inner hole 37 is further mitigated. In addition, the spinning liquid 31 discharged from such an inner hole 37 flows through the storage space 35 for a longer distance to reach the radiation hole 36. Therefore, the variation in the amount of the spinning liquid 31 sprayed to the outside from each radiation hole 36 is suppressed.

[0044] In addition, in the case of this embodiment, the inner hole 37 is provided at a position shifted from the position of the radiation hole 36 in the axial direction L1, specifically, at the center between two adjacent radiation holes 36. Such an inner hole 37 is located farther away from the radiation hole 36 than an inner hole provided at the same position in the axial direction as the position of the radiation hole. Therefore, the influence of the pressure difference, speed difference, etc. of the spinning liquid 31 discharged from the inner hole 37 is further mitigated. In addition, the spinning liquid 31 discharged from such an inner hole 37 flows a longer distance in the storage space 35 to reach the radiation hole 36. Therefore, the variation in the injection amount of the spinning liquid 31 sprayed to the outside from each radiation hole 36 is suppressed.

[0045] In addition, in the nozzle head 20, the spinning solution 31 supplied from the inner tube 32 into the storage space 35 is discharged from the inner hole 37 in a direction different from the direction of the radiation hole 36. In particular, in the case of this embodiment, the inner hole 37 is provided at a position shifted 180° in the circumferential direction around the axis L1 with respect to the position of the radiation hole 36, and at a position shifted to the center of the interval D of the radiation hole 36 in the direction of the axis L1. Therefore, the replacement of the spinning solution 31 in the storage space 35 is promoted, and the retention of the spinning solution 31 is suppressed.

[0046] (Effects of the First Embodiment) Next, the effects of this embodiment will be described. The spinning device 10 of this embodiment is equipped with a nozzle head 20. The nozzle head 20 is equipped with a solution tank 30 and a spinning electrode 50. The solution tank 30 is filled with the spinning solution 31 and is cylindrical with a plurality of spinning holes 36 for spraying the spinning solution 31. The spinning electrode 50 is disposed in the solution tank 30 in a state in contact with the spinning solution 31. The solution tank 30 has an outer tube 33 and an inner tube 32. The outer tube 33 is provided with a plurality of spinning holes 36 along the axis L1. The inner tube 32 is disposed in the outer tube 33 and supplies the spinning solution 31 into a storage space 35 formed between the outer tube 33 and the inner tube 32. The inner tube 32 has a plurality of inner holes 37 for discharging the spinning solution 31 into the storage space 35. The inner holes 37 and the radiation holes 36 are arranged in such a manner that the spinning solution 31 discharged from at least one of the inner holes 37 is discharged toward a region of the outer tube 33 where the radiation holes 36 are not formed. That is, the multiple inner holes 37 spray the spinning solution 31 in a direction different from the direction of the radiation holes 36.

[0047] In this way, in the nozzle head 20, the inner hole 37 and the spinning holes 36 are arranged such that the spinning liquid 31 discharged from at least one of the inner holes 37 is discharged toward the region of the outer tube 33 where the spinning holes 36 are not formed (specifically, the direction in which the inner wall surface of the outer tube 33 exists). That is, the spinning liquid 31 is discharged from the inner hole 37 in a direction different from the direction of the spinning holes 36. For this reason, compared with the case where the spinning liquid is directly discharged from the inner hole toward the region where the spinning holes are formed, the discharged spinning liquid 31 flows through the storage space 35 over a longer distance. As a result, even if there is a difference in the discharge amount of the spinning liquid 31 discharged from each inner hole 37, the difference can be alleviated while flowing through the storage space 35, and the injection amount of the spinning liquid 31 from each spinning hole 36 can be made uniform. Therefore, the nozzle head 20 and the spinning apparatus 10 including the same can achieve stabilization of the basis weight in the formed fiber aggregate.

[0048] In the nozzle head 20 of the spinning apparatus 10 according to the present embodiment, the inner hole 37 and the spinning holes 36 are arranged such that, when viewed from the direction of the axis L1, the discharge direction of the spinning liquid 31 discharged from the inner hole 37 (first discharge direction) and the discharge direction of the spinning liquid 31 discharged from at least one of the spinning holes 36 (second discharge direction) are at different angular positions on the circumference around the axis L1. That is, the inner hole 37 is provided at a position shifted in the circumferential direction around the axis L1 from the position of the spinning holes 36 with respect to the spinning holes 36. For this reason, the spinning liquid 31 discharged from the inner hole 37 can be made to flow through the storage space 35 over a longer distance in the circumferential direction around the axis L1 and reach the spinning holes 36. As a result, even if there is a difference in the discharge amount of the spinning liquid 31 discharged from each inner hole 37, the difference can be further alleviated while flowing through the storage space 35, and further uniformity of the injection amount of the spinning liquid 31 from each spinning hole 36 can be achieved.

[0049] In the nozzle head 20 of the spinning device 10 of this embodiment, the inner hole 37 and the radiation hole 36 are arranged in such a manner that the direction in which the spinning solution 31 is discharged from the inner hole 37 (first discharge direction) and the direction in which the spinning solution 31 is discharged from the radiation hole 36 (second discharge direction) are separated by a gap of 90° to 270° on the circumference around the axis L1. That is, when the solution tank 30 is viewed from the orthogonal direction of the imaginary plane P including the axis L1 and the radiation hole 36, the inner hole 37 is provided on the opposite side of the axis L1 from the position of the radiation hole 36. Therefore, the spinning solution 31 discharged from the inner hole 37 can be circulated in the storage space 35 over a longer distance in the circumferential direction around the axis L1 to reach the radiation hole 36. As a result, even if there is a difference in the amount of the spinning solution 31 discharged from each inner hole 37, the difference can be mitigated while flowing through the storage space 35, and the amount of the spinning solution 31 sprayed from each spinning hole 36 can be further uniformed.

[0050] In the nozzle head 20 of the spinning device 10 of this embodiment, the inner hole 37 and the spinning hole 36 are arranged in such a manner that the direction in which the spinning solution 31 is discharged from the inner hole 37 (first discharge direction) and the direction in which the spinning solution 31 is discharged from the spinning hole 36 (second discharge direction) are at positions 180° opposite to each other on the circumference around the axis L1. That is, the multiple inner holes 37 are provided in a virtual plane P including the axis L1 and the spinning hole 36. Therefore, the spinning solution 31 discharged from the inner hole 37 can be circulated in the storage space 35 over a longer distance in the circumferential direction around the axis L1 to reach the spinning hole 36. As a result, even if there is a difference in the discharge amount of the spinning solution 31 discharged from each inner hole 37, the difference can be mitigated while flowing through the storage space 35, and the spray amount of the spinning solution 31 from each spinning hole 36 can be further uniformed.

[0051] In the nozzle head 20 of the spinning device 10 of this embodiment, the position of the inner hole 37 in the axial line L1 direction is shifted from the position of each radiation hole 36 in the axial line L1 direction. That is, the multiple inner holes 37 are provided at a position shifted in the axial line L1 direction from the position of each radiation hole 36 with respect to the multiple radiation holes 36. For this reason, compared to when the axial position of the inner hole is the same as the axial position of the radiation hole, that is, when it is provided at the same axial position with respect to the position of the radiation hole, the spinning solution 31 discharged from the inner hole 37 of the inner tube 32 flows through the storage space 35 in the axial line L1 direction for a longer distance to reach the radiation hole. As a result, even if there is a difference in the discharge amount of the spinning solution 31 discharged from each inner hole 37, the difference can be mitigated while flowing through the storage space 35, and the amount of the spinning solution 31 sprayed from each radiation hole 36 can be further uniformed.

[0052] The spinning apparatus 10 of the present embodiment includes a nozzle head 20. This allows the spinning apparatus 10 to enjoy the effects of the nozzle head 20. Therefore, the spinning apparatus 10 can stabilize the basis weight of the fiber aggregate 14 that it forms.

[0053] An experiment was conducted to demonstrate the effect of the nozzle head according to the present disclosure. In the experiment, the discharge flow rate (spray amount) of the spinning solution 31 from each of the multiple radiation holes 36 was measured using the outer tube 33 and the inner tube 32 shown in FIG. 6. In the outer tube 33 of the experimental example, the multiple radiation holes 36 are formed at 16 locations at a constant interval D along the axis L1. In the experiment, the outer tube 33 was arranged so that each radiation hole 36 faces upward. In the inner tube 32 of the experimental example, the multiple inner holes 37 are formed at 8 locations at an interval 2D along the axis L1, that is, at a pitch twice that of the radiation holes 36. In the experiment, the inner tube 32 was coaxially arranged in the outer tube 33 so that each inner hole 37 was shifted 180° in the circumferential direction around the axis L1 relative to the radiation holes 36, that is, so that each inner hole 37 faces downward. The inner tube 32 was arranged so that the position of each inner hole 37 in the axial direction L1 was the same as the position of the even-numbered spinning holes 36 counting from the left side of Fig. 6. In the experiment, the spinning solution 31 was supplied from one end (the left side in Fig. 6) of the inner tube 32 at a constant pump pressure (0.2 MPa). The other end (the right side in Fig. 6) of the inner tube 32 was closed.

[0054] In addition, as a comparative example, the outer tube 33 and the inner tube 32 used in the experimental example were used, and the discharge flow rate of the spinning solution 31 from each spinning hole 36 was measured in the same manner when the spinning hole 36 and the inner hole 37 were both arranged facing upward, that is, when the inner hole 37 discharged the spinning solution 31 toward the spinning hole 36. The measurement conditions in this comparative example were the same as those in the above experiment, except that the inner hole was arranged facing upward. Under the measurement conditions in this comparative example, the even-numbered spinning holes 36 were easily affected by the discharge amount of the spinning solution 31 discharged from the inner hole 37, and the odd-numbered spinning holes 36 were less affected. The results are shown in FIG. 7. In addition, the "radiation hole number" on the horizontal axis in the graph of Figure 7 is a number assigned for convenience to the 16 radiation holes 36 in order of proximity to the supply port 61, such as number 1, number 2, number 3, ...

[0055] As shown in FIG. 7, the variation in the discharge flow rate from each radiation hole 36 in the experimental example was smaller than that in the comparative example. In detail, the difference between the maximum and minimum values ​​of the discharge flow rate from each radiation hole 36 was 0.39 ml / min in the comparative example, whereas in the experimental example, it was significantly smaller at 0.13 ml / min. This is presumed to be because, in the experimental example, the spinning solution was discharged from each inner hole in a direction different from the radiation hole, so that it collided with the inner wall of the outer tube and reached each radiation hole in a state in which its momentum was suppressed. In contrast, in the comparative example, it is presumed that the discharge flow rate from the even-numbered radiation hole, which was directly influenced by the discharge of the spinning solution from each inner hole in the direction of the even-numbered radiation hole, was larger than the discharge flow rate from the odd-numbered radiation hole. As described above, it has been demonstrated that when the position of the inner hole is shifted in the circumferential direction around the axis with respect to the position of the radiation hole as a configuration in which the inner hole discharges the spinning solution in a direction different from the direction of the radiation hole, the variation in the amount of the spinning solution sprayed from each radiation hole can be suppressed.

[0056] In addition, when focusing on the discharge flow rate from each radiator hole in the comparative example, the discharge flow rate from the odd-numbered radiator hole tends to be smaller than the discharge flow rate from the adjacent even-numbered radiator hole. In particular, the discharge flow rates from the adjacent radiator holes No. 3 and No. 5 are extremely small compared to the discharge flow rate from the radiator hole No. 4 in the comparative example. As described above, in the comparative example, each even-numbered radiator hole 36 is easily directly affected by the spinning solution 31 discharged from the inner hole 37, and each odd-numbered radiator hole 36 is less likely to be affected. That is, even if the direction of the positional shift of the inner hole relative to the position of the radiator hole is the axial direction, it can be said that the influence of the spinning solution discharged from each inner hole on the injection amount of the spinning solution sprayed from the radiator hole can be reduced, as with the circumferential positional shift. As described above, even when the position of the inner hole is shifted in the axial direction relative to the position of the radiation hole as a configuration in which the inner hole discharges the spinning solution in a direction different from the direction of the radiation hole, it has been demonstrated that the variation in the amount of the spinning solution sprayed from each radiation hole can be suppressed.

[0057] From the above experimental results, it can be said that the nozzle head according to the present disclosure is extremely effective in stabilizing the basis weight in the produced fiber assembly.

[0058] <Other Embodiments> The present invention is not limited to the embodiments described by the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention. (1) In the above Embodiment 1, the nozzle head had two supply ports, but it may have one or three or more supply ports. The supply port may be provided at a position other than the axial end in the solution tank, for example, at an intermediate portion in the axial direction, a central portion in the axial direction, or the like. (2) In the above Embodiment 1, the spinning electrode had a helical shape, but it may have other shapes such as a linear shape or a cylindrical shape. When the spinning electrode has a helical shape, the diameter, pitch, etc. of the helical shape do not have to be constant. Also, the diameter of the spinning electrode does not have to be uniform. (3) In the above Embodiment 1, the plurality of inner holes were provided at positions shifted in the circumferential direction around the axis from the positions of the plurality of spinning holes, but they may be provided at other positions. For example, the inner holes may be provided at the same position as the spinning holes in the circumferential direction around the axis, or may be provided at a position slightly shifted in the axial direction from that position. As the circumferential position of the inner holes with respect to the spinning holes, when viewed from the direction orthogonal to the plane including the axis and the spinning holes, it is preferably provided on the opposite side of the spinning holes across the axis, and more preferably provided within the plane including the axis and the spinning holes on the opposite side of the axis with respect to the spinning holes. That is, as the position on the circumference around the axis of the inner holes with respect to the spinning holes, when the position of the spinning holes is set to 0°, it is preferably in a mode with an interval of 90° or more and 270° or less, and more preferably provided at a position on the opposite side by 180°. (4) In the above-described Embodiment 1, the inner hole was provided at the center between adjacent spinning holes in the axial direction, but it may be provided at other positions. For example, the inner hole may be provided at a position overlapping the spinning hole in the axial direction or at a position slightly shifted in the axial direction from that position. The inner hole may be provided at a position shifted from the position of the spinning hole in at least one of the axial direction and the circumferential direction around the axis. (5) In the above-described Embodiment 1, the inner tube and the outer tube were cylindrical, but they may have other shapes. For example, at least one of the inner tube and the outer tube may be a polygonal cylindrical shape such as a square cylindrical shape. (6) In the above-described Embodiment 1, the plurality of inner holes were provided at equal intervals along the axial direction, but they may be provided at unequal intervals. In this case, the plurality of inner holes can be, for example, in a state of unequal intervals in which more inner holes are provided at a position farther from the supply port than near the supply port. (7) In the above-described Embodiment 1, all of the plurality of inner holes discharged the spinning solution vertically downward, but any one of the plurality of inner holes may discharge the spinning solution in a direction different from the other inner holes. In other words, the plurality of inner holes do not have to be arranged in a mode of discharging the spinning solution in the same direction. That is, in the nozzle head according to the present disclosure, as long as at least one of the plurality of inner holes discharges the spinning solution toward a region where no spinning hole is formed, the other inner holes may discharge the spinning solution in any direction. (8) The number of spinning holes is not limited to the above-described embodiment. The number of inner holes is also not limited to the above-described embodiment. (9) The second discharge direction according to the present disclosure is not limited to vertically upward. That is, in the spinning apparatus according to the present disclosure, it is not essential to eject the spinning solution vertically upward from the spinning hole, and for example, it may be ejected in a direction other than upward, such as laterally or downward.

[0059] The above examples are merely illustrative and should not be construed as limiting the present invention. Although the present invention has been described with reference to exemplary embodiments, the words used in describing and illustrating the present invention are understood to be descriptive and exemplary, rather than limiting. As detailed herein, changes may be made within the scope of the appended claims without departing from the scope or essence of the present invention in its form. Although the present invention has been described herein with reference to specific structures, materials and embodiments, it is not intended that the present invention be limited to the disclosures herein, but rather that the present invention extends to all functionally equivalent structures, methods and uses within the scope of the appended claims. [Explanation of symbols]

[0060] 10...Spinning device 11...Collection member 14...Fiber assembly 17…Collector electrode 20…Nozzle head 30…Solution tank 31...Spinning solution 32…Inner tube 33…Outer tube 35…Storage space 36...Spinning hole 37…Inner hole 38…Jet 50...Spinning electrode L1…Axis line

Claims

1. A nozzle head comprising a cylindrical solution tank having a plurality of spinning holes for filling the spinning solution therein and spraying the spinning solution, and a spinning electrode disposed in the solution tank in contact with the spinning solution, The solution tank includes an outer tube having a plurality of the spinning holes provided along the axis of the solution tank; an inner tube that is disposed in the outer tube and supplies the spinning solution into a storage space formed between the outer tube and the inner tube; The inner tube has a plurality of inner holes for discharging the spinning solution into the storage space, The inner hole and the spinning hole are arranged in such a manner that the spinning solution discharged from at least one of the inner holes is discharged toward a region of the outer tube where the spinning hole is not formed. Nozzle head.

2. When viewed from the direction of the axis, The first discharge direction of the spinning solution discharged from at least one of the inner holes and the second discharge direction of the spinning solution discharged from at least one of the spinning holes are at different angular positions around the axis. The nozzle head according to claim 1, wherein the inner holes and the spinning holes are arranged in such a manner that they are at different angular positions around the axis.

3. The nozzle head according to claim 2, wherein the inner hole and the radiation hole are arranged in such a manner that the first discharge direction and the second discharge direction are separated by a gap of 90° or more and 270° or less on a circumference around the axis.

4. The nozzle head according to claim 2 or 3, wherein the inner hole and the radiation hole are arranged in such a manner that the first discharge direction and the second discharge direction are 180° opposite positions on a circumference around the axis.

5. The nozzle head according to any one of claims 1 to 4, wherein the axial position of each of the inner holes is offset from the axial position of each of the radiation holes.

6. A nozzle head according to any one of claims 1 to 5; A collector electrode located at a distance from the spinning electrode; Equipped with A spinning device in which a voltage is applied between the spinning electrode and the collector electrode, so that a jet of the charged spinning solution is sprayed toward the collector electrode and turned into fibers, which are then collected as a fiber aggregate by a collecting member arranged along the surface of the collector electrode facing the spinning electrode.

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