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 a tubular outer pipe 33 on which the plurality of spinning holes 36 is provided, and a tubular inner pipe 32 that is disposed in the outer pipe 33 and has a plurality of inner holes 37 for discharging the spinning solution 31 into a storage space 35 formed between the inner pipe and the outer pipe 33 in the nozzle head 20. The plurality of spinning holes 36 is disposed at substantially equal intervals along an axis line L1 of the solution tank 30. At least some of the plurality of inner holes 37 are disposed at unequal intervals along the axis line L1.SELECTED DRAWING: Figure 5

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 includes: 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 has a tubular outer tube having a plurality of the spinning holes, and a tubular inner tube having a plurality of inner holes disposed in the outer tube and discharging the spinning solution into a storage space formed between the outer tube and the inner tube. The plurality of spinning holes are arranged at substantially equal intervals along the axis of the solution tank, At least some of the plurality of bores are non-equally spaced along the axis.

[0007] A spinning device according to one embodiment of the present disclosure comprises the nozzle head and a collector electrode arranged away from the spinning electrode, and when a voltage is applied between the spinning electrode and the collector electrode, a jet of charged spinning solution is sprayed toward the collector electrode and turned into fibers, which are then collected as a fiber aggregate by a collection member arranged along the surface of the collector electrode facing the spinning electrode. Effect of the Invention

[0008] According to the present disclosure, by making the intervals between the multiple inner holes that discharge the spinning solution at different discharge rates depending on the axial distance unequal, the supply amount of the spinning solution supplied from the entire inner tube to the storage space can be freely set in terms of the supply amount per unit length in the axial direction. As a result, by arranging the multiple inner holes in such a way that the supply amount per unit length is uniform, the injection amount of the spinning solution from each equally spaced 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 formed fiber aggregate. [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 explanatory diagram for explaining the arrangement of radiation holes in the outer tube of the first embodiment, and the arrangement of inner holes in the inner tube. [Figure 6] FIG. 6 is an explanatory diagram for explaining the arrangement of inner holes in the inner tube of the comparative example. [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 solution tank may have a supply port for supplying the spinning solution to the inside of the inner tube formed at the end in the axial direction. The number of the multiple inner holes may be greater in a separate region farther from the supply port than in the vicinity of the supply port. In this case, the arrangement of the multiple inner holes can be easily set to an arrangement that achieves uniformity in the supply amount of the spinning solution per unit length in the axial direction. For example, when comparing the inner holes formed in the vicinity region and the inner holes formed in the separate region with respect to the discharge amount of the spinning solution, the inner holes formed in the separate region discharge less spinning solution due to the influence of pressure loss. For this reason, by arranging more inner holes in the separate region than the inner holes in the vicinity region (arranging fewer inner holes in the vicinity region than the inner holes in the separate region), the supply amount of the spinning solution from the inner tube can be made uniform. As a result, it is possible to realize an even supply of the spinning solution to each of the spinning holes arranged at approximately equal intervals, and it is possible to achieve uniformity in the injection amount of the spinning solution from each spinning hole.

[0012] In the nozzle head according to the present disclosure, the first inner hole closest to the supply port among the plurality of inner holes can be positioned closer to the supply port than the first radiating hole closest to the supply port among the plurality of radiating holes. In this case, the amount of spinning solution injected from the first radiating hole, which is the radiating hole closest to the supply port among the plurality of radiating holes, can be easily adjusted. That is, the spinning solution discharged from the first inner hole, which is the inner hole closest to the supply port, and for the spinning solution having a relatively large discharge pressure, the distance over which the spinning solution flows in the storage space can be easily enlarged and set, so that the magnitude of the pressure loss during the flow in the storage space can be freely enlarged and set. As a result, the amount of spinning solution injected from the first radiating hole can be suitably suppressed.

[0013] <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.

[0014] (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.

[0015] 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.

[0016] 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.

[0017] The nozzle head 20 has a plurality of spinning holes 36 formed at approximately equal 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 changed.

[0018] As shown in Fig. 3 and Fig. 4, 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 line L1). The solution tank 30 is disposed with the axis line L1 aligned with the width direction of the collection member 11 (Y direction in each figure) (see Fig. 1, Fig. 2, etc.).

[0019] As shown in FIG. 3 and FIG. 4, 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 until the spinning solution 31 discharged from an inner hole 37 of the inner tube 32 (described later) is sprayed from the spinning hole 36.

[0020] 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.

[0021] 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 to 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. A plurality of radiation holes 36 are provided along the axis line L1. The plurality of radiation holes 36 are arranged in a row along the axis line L1. The plurality of radiation holes 36 are provided at approximately equal intervals of a distance D along the axis line L1. The distance D between adjacent radiation holes 36 is preferably 5 mm to 20 mm, for example, 10 mm. The interval between adjacent radiation holes 36 is the distance between the centers of each radiation hole 36. As shown in Fig. 5, in this embodiment, 35 radiation holes 36 are formed.

[0022] As shown in FIG. 3 to FIG. 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 solution 31 to the storage space 35. The inner hole 37 discharges the spinning solution 31 from the inside to the outside of the inner tube 32. A plurality of inner holes 37 are provided. The plurality of inner holes 37 are provided at unequal intervals along the axis L1. In the case of this embodiment, the intervals between the plurality of inner holes 37 are unequal intervals in a form in which the intervals between the plurality of spinning holes 36 are equal to the interval D, whereas the intervals between two adjacent inner holes 37 are an integer multiple of the interval D. Among the plurality of inner holes 37, the intervals between the inner holes 37 at the central position in the axis L1 direction away from the supply port 61 are set to 1 to 2 times the interval D. 5, five of the multiple inner holes 37 are provided at a center in the direction of the axis L1 with a spacing of D, and on both sides of the center in the direction outward, the multiple inner holes 37 are arranged at regular uneven intervals, such as twice the spacing D (2D), spacing D, spacing 2D, spacing D, etc. Such an arrangement of the multiple inner holes 37 can be said to be an arrangement in which some of the multiple inner holes are partially thinned out from the multiple inner holes arranged at equal intervals.

[0023] In the inner tube 32, the spacing between the inner holes 37 at the ends is set to be much larger than the spacing between the inner holes 37 at the center in the direction of the axis L1. Specifically, as shown in Fig. 5, the spacing between the first inner hole 37A, which is the inner hole closest to the supply port 61, and the second inner hole 37B, which is closest to the first inner hole 37A (second closest to the supply port 61), is set to 15 times (15D) the spacing D. The second inner hole 37B is the inner hole located on the outermost side (closest to the supply port 61) in the center.

[0024] Also, as shown in FIG. 5, in the present embodiment, among the plurality of inner holes 37, the first inner hole 37A closest to the supply port 61 is arranged at a position closer to the supply port 61 than the first spinning hole 36A closest to the supply port 61 among the plurality of spinning holes 36. In the case of the present embodiment, the distance in the direction of the axis L1 between the first inner hole 37A and the first spinning hole 36A is set to m times (mD) of the distance D. Further, the distance in the direction of the axis L1 between the first spinning hole 36A and the second inner hole 37B second closest to the supply port 61 is set to k times (kD) of the distance D. That is, when comparing the distances in the direction of the axis L1 from the first spinning hole 36A closest to the supply port 61, the first inner hole 37A is provided at a position closer to the first spinning hole 36A than the second inner hole 37B. The distances in the direction of the axis L1 between the first inner hole 37A and the second inner hole 37B with reference to the first spinning hole 36A are set such that the distance to the first inner hole 37A closer to the supply port 61 is smaller than the distance to the second inner hole 37B farther from the supply port 61 compared to the first inner hole 37A, and m < k holds. In the case of the present embodiment, m = 6 and k = 9.

[0025] Also, as shown in FIG. 5, the position farthest from the supply port 61 in the axial direction L1 of the solution tank 30 is the reference position C, and of the region from this reference position C to the position of the first radiation hole 36A, half of the region on the reference position C side is the "separate region R2" in the solution tank 30. Also, the entire region on the supply port 61 side from the separated region R2 is the "nearby region R1" in the solution tank 30. In this case, when comparing the number of inner holes 37 arranged in each of the near region R1 and the separated region R2, the number of inner holes 37 arranged in the separated region R2 is greater than the number of inner holes 37 arranged in the near region R1. Also, as shown in FIG. 5, the region on the supply port 61 side from the position of the first radiation hole 36A in the axial direction L1 of the near region R1 is the outer region R3. In this case, the multiple inner holes 37 are arranged such that at least one is provided in the outer region R3, and the number of inner holes provided in the outer region R3 is less than the number of inner holes provided in a region farther from the supply port 61 than the outer region R3. In the case of this embodiment, only one of the multiple inner holes 37 is provided in each of the nearby regions R1, and 6.5 inner holes are provided in each of the remote regions R2. Also, only one of the multiple inner holes 37 (only the first inner hole 37A) is provided in each of the outer regions R3. Note that in the present disclosure, multiple inner holes may be provided in the nearby region R1 and the outer region R3.

[0026] 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.

[0027] 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.

[0028] 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 50 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.

[0029] 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).

[0030] 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.

[0031] 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.

[0032] 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.

[0033] (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.

[0034] 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.

[0035] 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 simultaneously ejected from the multiple spinning holes 36 toward the collector electrode 17, respectively. As described above, in the nozzle head 20, the multiple inner holes 37 are arranged at unequal intervals. Specifically, the multiple inner holes 37 are arranged at unequal intervals in a manner in which the number of inner holes 37 is increased in the remote region R2 away from the supply port 61 compared to the nearby region R1 near the supply port 61. This reduces the bias in the amount of the spinning solution 31 sprayed from each spinning hole 36 in the nozzle head 20.

[0036] 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.

[0037] (Operation of embodiment 1) Next, the operation of this embodiment will be described. In the nozzle head 20, the multiple inner holes 37 are arranged at unequal intervals. The purpose of arranging the inner holes 37 at unequal intervals is to uniformize the amount of the spinning solution 31 sprayed to the outside from the spinning holes 36 arranged at approximately equal intervals. The amount of the spinning solution 31 discharged from each inner hole 37 is smaller for the inner hole 37 located relatively far from the supply source of the spinning solution 31 than for the inner hole 37 located relatively close to the supply source. This is due to the influence of pressure loss according to the distance in the axial direction L1 of the spinning solution 31 flowing through the inner tube 32. In this embodiment, the inner holes 37 are provided at unequal intervals. That is, in the nozzle head 20, the multiple inner holes 37 are provided more in the center of the inner tube 32, which is located away from the supply port 61, than at the end of the inner tube 32, which is near the supply port 61. This adjusts the number of inner holes 37 per unit length in the axial direction L1 of the inner tube 32, and adjusts the supply amount per unit length of the spinning solution 31 supplied from the entire inner tube 32 into the storage space 35. This allows the spinning solution 31 in the storage space 35 to be evenly supplied to each spinning hole 36, and reduces the variation in the amount of the spinning solution 31 sprayed from each spinning hole 36.

[0038] In addition, the first inner hole 37A, which is the inner hole closest to the supply port 61 among the multiple inner holes 37, is formed at a position closer to the supply port 61 than the first radiation hole 36A, which is the radiation hole closest to the supply port 61 among the multiple radiation holes 36. By arranging in this manner, the injection amount from the first radiation hole 36A can be freely adjusted without significantly affecting the injection amount of the spinning liquid 31 from the other radiation holes 36. As described above, the ejection amount of the spinning liquid 31 discharged from the first inner hole 37A closest to the supply port 61 is larger than that of the other inner holes 37. This is due to the influence of pressure loss according to the distance in the axis L1 direction of the spinning liquid 31. In the nozzle head 20 according to this embodiment, the difference in the magnitude of the pressure loss due to the difference in the distance flowing through the inner tube 32 is absorbed and mitigated by the pressure loss when the spinning liquid is discharged into the storage space 35 and flows through the storage space 35. That is, in the nozzle head 20, the first inner hole 37A, which has the smallest pressure loss and therefore the largest discharge amount of the spinning solution 31, is disposed at a position farther from the spinning hole 36 than the other inner holes 37. This allows the spinning solution 31 discharged from the first inner hole 37A to circulate through the storage space 35 over a longer distance, causing a larger pressure loss than that occurring in the spinning solution 31 discharged from the other inner holes 37, thereby mitigating the difference.

[0039] Here, for example, it is assumed that the first inner hole 37A is provided at a position farther from the supply port 61 than the first radiation hole 36A. In this case, the first inner hole 37A is arranged closer to the other radiation holes 36 other than the first radiation hole 36A than the first radiation hole 36A. In this case, the first inner hole 37A has the same effect as when it is arranged closer to the supply port 61 than the first radiation hole 36A with respect to the first radiation hole 36A. However, in this case, the first inner hole 37A affects the amount of the discharge amount of the spinning solution 31 on the injection amount of the other radiation holes 36 arranged closer than the first radiation hole 36A. For this reason, when the first inner hole 37A is arranged at a position farther from the supply port 61 than the first radiation hole 36A, it is difficult to uniformize the injection amount of the spinning solution 31 from each radiation hole 36. In contrast, by positioning the first inner hole 37A closer to the supply port 61 than the first radiation hole 36A, there are no other radiation holes 36 between the first inner hole 37A and the first radiation hole 36A, so the injection amount of the first radiation hole 36A can be freely adjusted.

[0040] (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 arranged 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 tubular with a plurality of spinning holes 36 provided along the axis L1. The inner tube 32 is tubular with a plurality of inner holes 37 for discharging the spinning solution 31 into the storage space 35 formed between the outer tube 33 and the inner tube 32. The plurality of spinning holes 36 are arranged at approximately equal intervals along the axis L1 of the solution tank 30. And, the plurality of inner holes 37 are arranged at unequal intervals along the axis L1.

[0041] With this configuration, the nozzle head 20 provided in the spinning device 10 can freely set the supply amount of the spinning solution 31 supplied from the inner tube 32 into the storage space 35 in terms of the supply amount per unit length in the direction of the axis L1. For this reason, for example, by arranging the multiple inner holes 37 in such a way that the supply amount per unit length is uniformized, it is possible to realize an even supply of the spinning solution 31 to each of the spinning holes 36 arranged at equal intervals. As a result, it is possible to uniformize the amount of the spinning solution 31 sprayed from each of the spinning holes 36. Therefore, the nozzle head 20 of this embodiment and the spinning device 10 provided with it can stabilize the basis weight in the fiber aggregate to be formed.

[0042] In the nozzle head 20 of the spinning device 10 of this embodiment, the solution tank 30 has a supply port 61 for supplying the spinning solution 31 to the inside of the inner tube 32 formed at the end in the direction of the axis L1, and the number of the multiple inner holes 37 is greater in the separated region R2 farther from the supply port 61 than in the vicinity region R1 of the supply port 61. Therefore, the arrangement of the multiple inner holes 37 can be easily set to an arrangement that uniformizes the supply amount of the spinning solution 31 per unit length in the direction of the axis L1. As a result, it is possible to realize an even supply of the spinning solution 31 to each of the spinning holes 36 arranged at approximately equal intervals, and it is possible to uniformize the amount of the spinning solution 31 sprayed from each of the spinning holes 36.

[0043] In the nozzle head 20 of the spinning device 10 of this embodiment, the first inner hole 37A, which is the closest to the supply port 61 among the multiple inner holes 37, is located closer to the supply port 61 than the first radiation hole 36A, which is the closest to the supply port 61 among the multiple radiation holes 36. Therefore, the amount of spinning solution 31 sprayed from the first radiation hole 36A, which is the radiation hole 36 closest to the supply port 61 among the multiple radiation holes 36, can be easily adjusted. That is, for the spinning solution 31 with a relatively large discharge pressure discharged from the first inner hole 37A, the distance flowing through the storage space 35 can be easily enlarged and set, and the magnitude of the pressure loss can be freely enlarged and set. As a result, the amount of spinning solution 31 sprayed from the first radiation hole 36A can be suitably suppressed.

[0044] 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.

[0045] 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 described in the above embodiment. In the experiment, the spinning solution 31 was supplied from both ends of the inner tube 32 at a constant pump pressure (0.2 MPa). In the experiment, the discharge flow rate was measured for every fifth radiation hole 36 in the axial line L1 direction, such as the first, fifth, tenth, ..., from the left, of the 35 radiation holes 36 formed in the outer tube 33.

[0046] In addition, as a comparative example, the discharge flow rate of the spinning solution 31 from each radiation hole 36 was measured in the same manner using the outer tube 33 used in the experimental example and the inner tube 232 (see FIG. 6) having a plurality of inner holes 237 formed at approximately equal intervals equal to the interval D of the plurality of radiation holes 36 formed in the outer tube 33. As shown in FIG. 6, in the inner tube 232 of the comparative example, the plurality of inner holes 237 were formed in the same number (35) as the number of the plurality of radiation holes 36 in the outer tube 33, and were arranged so as to be at the same position in the axial line L1 direction as each radiation hole 36. Other measurement conditions in this comparative example are the same as those in the above experimental example. 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 from left to right to the 35 radiation holes 36, such as number 1, number 2, number 3, .... In other words, the radiation holes 36 whose discharge flow rate was measured are number 1, number 5, number 10, number 15, number 20, number 25, number 30, and number 35.

[0047] 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. Specifically, the difference between the maximum and minimum values ​​of the discharge flow rate from each radiation hole 36 was 0.06 ml / min in the comparative example, whereas it was significantly smaller at 0.015 ml / min in the experimental example. This is presumably because, in the experimental example, the inner holes 37 were arranged at unequal intervals, thereby reducing the difference in the supply amount per unit length in the axial line L1 direction of the spinning solution 31 supplied from the inner tube 32 into the storage space 35. In contrast, in the comparative example, the inner holes 237 were arranged at equal intervals, so it is presumed that the difference in the supply amount per unit length of the spinning solution 31 supplied from the inner tube 232 into the storage space 35 is directly reflected. In this way, it has been demonstrated that by arranging multiple inner holes 37 at unequal intervals along the axis L1 direction and freely adjusting the amount of spinning solution 31 discharged from each inner hole 37, the amount of spinning solution 31 sprayed from each spinning hole 36 can be freely adjusted.

[0048] In addition, in each of the experimental examples and comparative examples, when focusing on the discharge flow rate of the spinning solution 31 from the first radiation hole 36A (radiation holes with numbers 1 and 35) located closest to the supply port 61, the discharge flow rate of the first radiation hole 36A in the comparative example was 0.11 ml / min, while the discharge flow rate of the first radiation hole 36A in the experimental example was 0.06 ml / min. That is, the discharge flow rate of the spinning solution 31 from the first radiation hole 36A in the experimental example is suppressed to about half of that in the comparative example. In addition, in each of the experimental examples and comparative examples, attention is paid to the discharge flow rate of the spinning solution 31 from the radiation hole 36 with number 20 shown in FIG. 6, that is, the radiation hole 36 located farthest from the supply port 61 among the radiation holes 36 whose discharge flow rate was measured. The discharge flow rate of the spinning solution 31 from the radiation hole 36 with number 20 in the comparative example was 0.05 ml / min. In contrast, the discharge flow rate of the spinning solution 31 from the radiation hole 36 of No. 20 in the experimental example was 0.045 ml / min, and the difference from the comparative example was only 0.005 ml / min. This is presumably because the inner holes 37, 237 are arranged at approximately equal intervals in the central portion in the axial direction L1 away from the supply port 61 in each of the inner tubes 32, 232 in the experimental example and the comparative example. In this way, by arranging multiple inner holes 37 at unequal intervals along the axial line L1, it was demonstrated that the spinning solution 31 can be discharged at a desired discharge rate from each inner hole 37, and the injection amount of the spinning solution 31 from each radiation hole 36 can be freely adjusted.

[0049] From the above experimental results, it is apparent that the nozzle head according to the present disclosure is effective in stabilizing the basis weight in the resulting fiber aggregate.

[0050] <Other embodiments> The present invention is not limited to the embodiment described above and illustrated in the drawings, and the following embodiments, for example, are also included within the technical scope of the present invention. (1) In the above embodiment 1, the nozzle head has two supply ports, but the number of supply ports may be one or three or more. The supply port may be provided at a position other than the end in the axial direction of the solution tank, for example, at a middle part in the axial direction, a center part in the axial direction, etc. (2) In the above embodiment 1, the spinning electrode has a helical shape, but it may have other shapes, such as a straight line, a cylindrical shape, etc. When the spinning electrode has a helical shape, the diameter, pitch, etc. of the helical shape do not have to be uniform. (3) In the above embodiment 1, as a form in which a plurality of inner holes are provided at a position away from the supply port more than near the supply port, a form in which one inner hole is formed on the supply port side of the radiator hole closest to the supply port and a plurality of inner holes are formed on the opposite side of the supply port is exemplified. The present disclosure is not limited thereto. As a form in which a plurality of inner holes are provided at a position away from the supply port more than near the supply port, for example, when the radiator hole closest to the supply port is used as a reference, two or more inner holes may be provided on the supply port side of the radiator hole. That is, among the plurality of inner holes, inner holes other than the inner hole closest to the supply port may also be formed at a position closer to the supply port than the radiator hole closest to the supply port among the plurality of radiators. (4) In the above embodiment 1, the inner hole is provided with an opening toward the top, that is, in the same direction as the radiation hole, but it may be provided with an opening toward another direction, for example, downward when the radiation hole is provided with an opening toward the top. In addition, the inner hole may be, for example, in a form in which the spinning solution is discharged in a direction different from the direction of the radiation hole. The inner hole may be provided at a position shifted from the position of the radiation hole in at least one direction of the axial direction from the position of the radiation hole and the circumferential direction around the axis. In addition, it is sufficient that at least a part of the multiple inner holes are arranged at unequal intervals. That is, the multiple inner holes may be arranged at unequal intervals as a whole, or may be arranged at approximately equal intervals when viewed partially. (5) In the first embodiment, the inner tube and the outer tube are cylindrical, but may be other shapes. For example, at least one of the inner tube and the outer tube may be polygonal, such as a square tube. (6) The number of radiation holes is not limited to the above embodiment, and the number of inner holes is also not limited to the above embodiment. (7) In the spinning device according to the present disclosure, it is not essential that the spinning solution be sprayed upward from the spinning hole. For example, the spinning solution may be sprayed in a direction other than upward, such as sideways or downward.

[0051] 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]

[0052] 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 (36A... first spinning hole) 37...Inner hole (37A...1st inner hole, 37B...2nd inner hole) 38…Jet 50...Spinning electrode 61…Supply inlet L1…Axis line R1: Nearby region R2…isolation area

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 has a tubular outer tube having the plurality of spinning holes, and a tubular inner tube arranged in the outer tube and having a plurality of inner holes for discharging the spinning solution into a storage space formed between the outer tube and the inner tube. The plurality of spinning holes are arranged at substantially equal intervals along the axis of the solution tank, At least some of the plurality of bores are non-equally spaced along the axis.

2. the solution tank has a supply port formed at an end in the axial direction for supplying the spinning solution to the inside of the inner tube, The nozzle head according to claim 1 , wherein a number of the plurality of inner holes is greater in a remote region farther from the supply port than in a vicinity of the supply port.

3. 3. The nozzle head according to claim 2, wherein the first inner hole closest to the supply port among the plurality of inner holes is located closer to the supply port than the first radiation hole closest to the supply port among the plurality of radiation holes.

4. The nozzle head according to any one of claims 1 to 3, 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.

Images