Nozzle head and electrospinning device

Abstract

To accelerate ultrafine fiber formation from spinning liquid.SOLUTION: A nozzle head 10 comprises: a head body 11; a nozzle 25 to make spinning liquid L ejected from a spinning hole 26 that opens on an outer surface of the head body 11; and a spinning electrode 21 to generate potential difference between itself and a collector electrode 34 disposed near a collecting member 35. The nozzle head 10 is constituted so as to make the collecting member 35 collect the spinning liquid L that is ejected from the nozzle 25 and formed into ultrafine fibers by electrostatic force. The nozzle 25 has a conductive protrusion part 27, which protrudes from the outer surface of the head body 11 so as to allow the spinning liquid L to come in contact therewith and is conductible with the spinning electrode 21.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a nozzle head and an electrospinning device. [Background technology]

[0002] Patent Document 1 discloses an electrospinning apparatus that produces a fiber aggregate made of ultrafine fibers by collecting the spinning solution sprayed from the spinning holes of a nozzle head in the form of ultrafine fibers on a sheet-like collecting member. The spinning solution sprayed from the spinning holes is charged by contact with a spinning electrode provided in the nozzle head, and becomes ultrafine fibers due to the potential difference between the spinning electrode and a collector electrode provided near the collecting member. This electrospinning apparatus has the advantage of easily producing ultrafine fibers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-074630 Summary of the Invention [Problem to be solved by the invention]

[0004] The nozzle head is charged by direct contact with the spinning electrode or indirect contact via the spinning solution. It is inevitable that a portion of the spinning solution discharged from the spinning hole will adhere to the outer surface of the nozzle head without forming a jet. The spinning solution adhering to the nozzle head grows into a whisker-like shape due to the electrostatic force between the spinning solution and the collector electrode, and the charge of the nozzle head is concentrated on the whisker-like spinning solution. When the charge concentrates on the whisker-like spinning solution, the charge at the spinning hole decreases, so the amount of charge on the spinning solution ejected from the spinning hole decreases, and the spinning solution is suppressed from being converted into ultrafine fibers. As a countermeasure, it is possible to increase the potential difference between the spinning electrode and the collector electrode. However, if the potential difference is increased, the speed of the jet of the spinning solution increases, so the spinning solution may adhere to the collecting member without being sufficiently converted into ultrafine fibers, resulting in uneven basis weight.

[0005] The present disclosure was completed based on the above circumstances, and aims to promote the production of ultrafine fibers from a spinning solution. [Means for solving the problem]

[0006] The nozzle head of the first disclosure comprises: A head body, A nozzle that sprays a spinning solution from a spinning hole opening on the outer surface of the head body; a spinning electrode that generates a potential difference between itself and a collector electrode disposed near the collection member; A nozzle head configured to collect the spinning solution ejected from the nozzle in the state of being converted into ultrafine fibers by electrostatic force by the collecting member, The nozzle protrudes from the outer surface of the head body to allow contact with the spinning solution, and has a conductive protrusion that can be electrically connected to the spinning electrode.

[0007] The electrospinning apparatus of the second disclosure comprises: A nozzle head; a collector electrode disposed in the vicinity of the collection member; The nozzle head is A head body, A nozzle that sprays a spinning solution from a spinning hole opening on the outer surface of the head body; A spinning electrode that generates a potential difference between itself and the collector electrode, The nozzle protrudes from the outer surface of the head body to allow contact with the spinning solution, and has a conductive protrusion that can be electrically connected to the spinning electrode, The spinning solution ejected from the nozzle is converted into ultrafine fibers by electrostatic force and collected by the collecting member. [Effects of the Invention]

[0008] The nozzle head of the first disclosure and the electrospinning device of the second disclosure can promote the formation of ultrafine fibers from the spinning solution. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view showing an outline of an electrospinning apparatus according to a first embodiment. [Figure 2] FIG. 2 is a side view showing an outline of the electrospinning apparatus. [Figure 3] FIG. 3 is a plan view of the nozzle head. [Figure 4] FIG. 4 is a cross-sectional view taken along line XX in FIG. [Figure 5] FIG. 5 is a cross-sectional view of the nozzle head of the second embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the nozzle head of the third embodiment. [Figure 7] FIG. 7 is a cross-sectional view of the nozzle head of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Here, preferred embodiments of the present disclosure will be described. Any combination of the following embodiments without causing any contradiction is also included in the embodiments for carrying out the invention.

[0011] (1) The nozzle head of the first disclosure comprises a head body, a nozzle that ejects a spinning solution from a spinning hole opening on the outer surface of the head body, and a spinning electrode that generates a potential difference between the nozzle and a collector electrode arranged near a collecting member. The spinning solution ejected from the nozzle is collected by the collecting member in a state of being converted into ultrafine fibers by electrostatic force. The nozzle protrudes from the outer surface of the head body to enable contact with the spinning solution, and has a conductive protrusion that can be electrically connected to the spinning electrode. According to this configuration, when a potential difference occurs between the spinning electrode and the collector electrode, charge concentrates on the protrusion protruding from the opening edge of the spinning hole without increasing the potential difference between the spinning electrode and the collector electrode. Since the potential difference between the spinning electrode and the collector electrode does not become too large, the speed of the spinning solution jet does not become too fast, and time is secured to convert the spinning solution into ultrafine fibers. When the spinning solution passes through the spinning holes, it comes into contact with the protrusions, and the spinning solution ejected from the spinning holes is sufficiently charged. Therefore, according to the first disclosure, it is possible to promote the spinning solution to be turned into ultrafine fibers.

[0012] (2) In (1), it is preferable that the cross-sectional area of the nozzle cut perpendicular to the direction in which the spinning solution is ejected decreases in the direction in which the protrusions protrude. With this configuration, electric charges are likely to be concentrated on the protrusions.

[0013] (3) In (1) or (2), it is preferable that the thickness of the protrusions decreases in the direction of protrusion of the protrusions. With this configuration, electric charges tend to concentrate on the protrusions.

[0014] (4) In (1) or (2), the protrusion preferably has a cylindrical shape that is connected around the entire circumference. With this configuration, the contact area of the protrusion with the spinning solution is increased, thereby increasing the efficiency of charging the spinning solution.

[0015] (5) In the configuration (1) or (2), it is preferable that the head body is made of a conductor and is electrically conductive with the protrusions. With this configuration, the electric charge on the outer surface of the head body can be concentrated on the protrusions, thereby preventing the spinning solution adhering to the outer surface of the head body from growing into whiskers.

[0016] (6) In (1) or (2), it is preferable that the nozzle can be attached to and detached from the head body by screwing it in. This configuration makes maintenance of the nozzle easy, and allows replacement of the nozzle alone.

[0017] (7) In (1) or (2), the nozzle is preferably made of stainless steel. With this configuration, it is easier to concentrate electric charge on the protrusion than when the nozzle is made of a conductive resin material.

[0018] (8) The electrospinning apparatus of the second disclosure includes a nozzle head and a collector electrode arranged near a collecting member, and the nozzle head has a head body, a nozzle that sprays the spinning solution from a spinning hole opening on the outer surface of the head body, and a spinning electrode that generates a potential difference between the nozzle and the collector electrode, and the nozzle protrudes from the outer surface of the head body to enable contact with the spinning solution and has a conductive protrusion that can be electrically connected to the spinning electrode, and the spinning solution sprayed from the nozzle is collected in the collecting member in a state where it has been converted into ultrafine fibers by electrostatic force. According to the second disclosure, as in the second disclosure, it is possible to promote the conversion of the spinning solution into ultrafine fibers.

[0019] <Embodiment 1> A first embodiment of the present disclosure will be described with reference to Figures 1 to 4. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. In this first embodiment, with regard to the front-to-back direction, the F direction in Figures 2 and 3 is defined as the front. With regard to the up-down direction, the H direction in Figures 1 to 4 is defined as the up. With regard to the left-to-right direction, the R direction in Figures 1 and 4 is defined as the right.

[0020] 1 and 2 is an apparatus for producing a fiber aggregate by spinning ultrafine fibers F (nanofibers) from a spinning solution L and collecting the ultrafine fibers F on a collecting member 35. An example of the fiber aggregate is a nonwoven fabric used as a separator for a secondary battery (not shown).

[0021] The spinning solution L contains a resin material that forms the ultrafine fibers F as a solute, which is dissolved or dispersed in a volatile solvent. Examples of the solute include synthetic resins such as polyacrylonitrile (PAN), polypropylene (PP), and polyethylene (PE). Examples of the solvent include compounds such as N,N-dimethylacetamide (DMA), N,N-dimethylformamide (DMF), and tetrahydrofuran (THF).

[0022] The electrospinning apparatus A is configured to include a nozzle head 10 , a collector electrode 34 , a transport device 30 for transporting a collection member 35 , a tank 18 , a pump 19 , and a DC power supply 20 .

[0023] As shown in Figures 3 to 5, the nozzle head 10 includes a head body 11 and a spinning electrode 21. The head body 11 stores the amount of spinning solution L required for spinning and supplies the spinning solution L to a nozzle 25 described later. The head body 11 has a cylindrical shape with its axis oriented horizontally (front-rear direction) as a whole. The axis of the head body 11 is parallel to the width direction of a collection member 35 described later.

[0024] The head body 11 has a double-tube structure consisting of a cylindrical inner tube 12 and a cylindrical outer tube 13 that concentrically surrounds the inner tube 12. The inner tube 12 is made of, for example, a solvent-resistant resin. The solvent-resistant resin is, for example, a synthetic resin such as a fluororesin (PTFE).

[0025] The internal space of the inner tube 12 functions as a first supply path 14 for storing and flowing the spinning solution L. The space between the outer peripheral surface of the inner tube 12 and the inner peripheral surface of the outer tube 13 functions as a second supply path 15 for storing and flowing the spinning solution L. A plurality of inner holes 16 spaced apart in the axial direction are formed at the lower end of the inner tube 12. The inner holes 16 penetrate the inner tube 12 in the vertical direction and connect the first supply path 14 and the second supply path 15. The downstream ends of two pipes 17 are connected to both ends of the inner tube 12, respectively. Note that, for convenience, only one of the two pipes 17 is shown in FIG. 1. The upstream end of the pipe 17 is connected to a tank 18 in which the spinning solution L is stored. A pump 19 is provided in the middle of the pipe 17 to pressure-feed the spinning solution L in the tank 18 to the nozzle head 10.

[0026] The outer tube 13 is a single component made of stainless steel. The outer tube 13 includes a cylindrical main body 23 arranged concentrically with the inner tube 12, and a plurality of nozzles 25. One axial end of the cylindrical main body 23 is connected to the positive electrode of the DC power supply 20. The outer tube 13 functions as a spinning electrode 21.

[0027] The multiple nozzles 25 are arranged at multiple positions spaced apart in the axial direction on the outer peripheral surface of the cylindrical main body 23. The nozzles 25 have radiation holes 26 and protrusions 27. A plurality of through holes 28 penetrating from the inner peripheral surface to the outer peripheral surface of the cylindrical main body 23 are formed at the upper end of the cylindrical main body 23. The nozzles 25 include opening edge portions of the through holes 28 in the cylindrical main body 23. The protrusions 27 are portions that protrude upward from the opening edge portions of the through holes 28 on the outer peripheral surface of the cylindrical main body 23.

[0028] The internal space of the protrusion 27 communicates with the through-hole 28 and forms the central hole of the nozzle 25. The entire central hole of the nozzle 25 functions as a radiation hole 26 with its axis directed in the vertical direction. The radiation hole 26 is a space that connects the second supply path 15 with the external space above the head body 11 (nozzle 25). The radiation hole 26 opens to the upper end surface of the nozzle 25 and also opens to the inner circumferential surface of the outer tube 13 (cylindrical main body 23). In a plan view of the nozzle head 10 viewed from above, the opening shape of the through-hole 28 and the inner circumferential surface shape of the protrusion 27 are concentric circles of the same diameter. The inner circumferential surface of the radiation hole 26 is smoothly continuous from the second supply path 15 to the protruding end of the protrusion 27 (the upper end of the nozzle 25).

[0029] The protrusion 27 has a cylindrical shape with its axis facing up and down. The outer peripheral surface of the protrusion 27 has a truncated cone shape. The inner diameter of the radiation hole 26 is constant from the second supply path 15 to the protruding end of the protrusion 27 (the upper end of the nozzle 25). Therefore, in a horizontal cross section of the protrusion 27 cut perpendicularly to the axis of the protrusion 27 (nozzle 25), the cross-sectional area of the protrusion 27 gradually decreases from the outer peripheral surface of the cylindrical main body 23 toward the protruding end of the protrusion 27. In addition, the radial thickness of the protrusion 27 also gradually decreases from the outer peripheral surface of the cylindrical main body 23 toward the protruding end of the protrusion 27.

[0030] The conveying device 30 is a device for conveying the capturing member 35 in the horizontal direction (left-right direction) above the nozzle head 10. The capturing member 35 is a long, sheet-shaped member. The conveying device 30 is configured to include a feed roller 31 and a take-up roller 32, which are arranged at the same height and spaced apart in the left-right direction. The capturing member 35 is wound around the feed roller 31. The leading end of the capturing member 35 in the conveying direction is wound around the take-up roller 32. In the spinning process, the capturing member 35 wound around the feed roller 31 is wound around the take-up roller 32 while moving horizontally (to the right) between the rollers 31 and 32.

[0031] The collector electrode 34 is disposed between the delivery roller 31 and the take-up roller 32. The collector electrode 34 is disposed along the upper surface of the collection area of the collection member 35, which is stretched horizontally between the rollers 31 and 32. The positive electrode of the DC power supply 20 is connected to the spinning electrode 21, and the negative electrode is connected to the collector electrode 34.

[0032] Next, a method for producing a fiber aggregate will be described. The first supply path 14 and the second supply path 15 of the nozzle head 10 are filled with the spinning solution L. When the electrospinning apparatus A is operated, the DC power supply 20 is closed, and in the nozzle head 10, the outer tube 13 serving as the spinning electrode 21 and the nozzle 25 integrally formed with the outer tube 13 are positively charged. A collecting member 35 is horizontally fed at a constant speed from the feed roller 31 to the take-up roller 32 while in contact with or close to the lower surface of the collector electrode 34. By driving the pump 19, the spinning solution L in the tank 18 is supplied to the first supply path 14 of the inner tube 12, passes through the inner hole 16, and is supplied to the second supply path 15. The second supply path 15 functions as a buffer space for the spinning solution L discharged from the inner hole 16.

[0033] The spinning solution L in the second supply path 15 is in contact with the outer tube 13 serving as the spinning electrode 21 and is therefore positively charged. The spinning solution L that has passed through the spinning hole 26 is sprayed upward from the spinning hole 26 by an electrostatic force (Coulomb force) caused by the potential difference between the spinning electrode 21 and the collector electrode 34, and is attracted to the collector electrode 34. The spinning solution L sprayed upward from the nozzle 25 becomes ultrafine fibers F due to the repulsive force of the charges accumulated in the spinning solution L in the process of rising from the nozzle head 10 toward the collecting member 35. As the formation of ultrafine fibers F progresses, the charge density of the ultrafine fibers F becomes higher, so the repulsive force between the charged ultrafine fibers F increases, and each ultrafine fiber F is split into even thinner ultrafine fibers F.

[0034] Through this process, ultrafine fibers F are spun and collected on the lower surface of the collecting member 35, thereby forming a fiber aggregate. The collecting member 35 on which the fiber aggregate is layered is taken up by the take-up roller 32. When using the fiber aggregate, the fiber aggregate is peeled off from the collecting member 35 while the collecting member 35 is pulled out from the take-up roll.

[0035] In order to promote the conversion of the spinning solution L into ultrafine fibers F, it is preferable to increase the amount of charge on the spinning solution L. One possible method for increasing the amount of charge is to increase the potential difference between the spinning electrode 21 and the collector electrode 34. However, if the potential difference is increased, the speed of the jet of the spinning solution L increases, so that the spinning solution L may reach the collection member 35 in a state where it is not sufficiently converted into ultrafine fibers F, which may result in uneven basis weight. Therefore, in this Example 1, a protrusion 27 protruding from the outer peripheral surface of the cylindrical main body 23 was formed as a site for concentrating the charge without increasing the potential difference between the spinning electrode 21 and the collector electrode 34.

[0036] The protrusions 27 have a smaller cross-sectional area than the cylindrical main body 23 and have a pointed tip, so the amount of charge on the protrusions 27 is greater than that on the cylindrical main body 23. In other words, even if the potential difference between the spinning electrode 21 and the collector electrode 34 is small, the charge can be concentrated on the protrusions 27. Since the spinning solution L comes into contact with the inner surface of the protrusions 27 while passing through the spinning holes 26 of the nozzle 25, the amount of charge on the spinning solution L increases while the spinning solution L passes through the protrusions 27 (spinning holes 26). The increase in the amount of charge on the spinning solution L promotes the spinning solution L to become ultrafine fibers F. In addition, since it is not necessary to increase the potential difference between the spinning electrode 21 and the collector electrode 34, the speed of the spinning solution L sprayed from the spinning holes 26 (nozzle 25) does not become too fast. This ensures the time required for the spinning solution L to become ultrafine fibers F until it reaches the collecting member 35.

[0037] The electrospinning apparatus A of this embodiment 1 includes a nozzle head 10 and a collector electrode 34 arranged near a collecting member 35. The electrospinning apparatus A and the nozzle head 10 collect the spinning solution L sprayed from the nozzle 25 in the collecting member 35 in a state where it is converted into ultrafine fibers F by electrostatic force. The nozzle head 10 includes a head main body 11, a nozzle 25, and a spinning electrode 21. The nozzle 25 is a part that sprays the spinning solution L from a spinning hole 26 opening on the outer surface of the head main body 11 (outer tube 13). The spinning electrode 21 generates a potential difference between itself and the collector electrode 34 arranged near the collecting member 35. The nozzle 25 has a protrusion 27. The protrusion 27 protrudes from the outer surface of the head main body 11 to enable contact with the spinning solution L, and is a conductive part that can be electrically connected to the spinning electrode 21.

[0038] According to this configuration, when a potential difference occurs between the spinning electrode 21 and the collector electrode 34, electric charges are concentrated on the protrusion 27 protruding from the opening edge of the spinning hole 26, even if the potential difference between the spinning electrode 21 and the collector electrode 34 is not increased. Since the potential difference between the spinning electrode 21 and the collector electrode 34 does not become too large, the speed of the jet of the spinning solution L does not become too fast, and a time margin for converting the spinning solution L into ultrafine fibers F is secured. When the spinning solution L passes through the spinning hole 26, it comes into contact with the protrusion 27, and the spinning solution L ejected from the spinning hole 26 is sufficiently charged. Therefore, according to the first disclosure, it is possible to promote the conversion of the spinning solution L into ultrafine fibers F.

[0039] The cross-sectional area of the nozzle 25 cut perpendicular to the ejection direction of the spinning solution L decreases in the direction in which the protrusions 27 protrude, so that electric charges tend to concentrate on the protrusions 27. The radial thickness of the protrusions 27 decreases in the direction in which the protrusions 27 protrude, so that electric charges tend to concentrate on the protrusions 27. The nozzle 25 is made of stainless steel, so that electric charges tend to concentrate on the protrusions 27 more easily than when the nozzle 25 is made of a conductive resin material.

[0040] The protrusions 27 have a cylindrical shape that is connected around the entire circumference. With this configuration, the contact area of the protrusions 27 with the spinning solution L is increased, thereby increasing the efficiency of charging the spinning solution L. The outer tube 13 of the head body 11 is made of a conductor and is capable of electrical conduction with the protrusions 27. With this configuration, the charge on the outer surface of the head body 11 can be concentrated on the protrusions 27, thereby preventing the spinning solution L attached to the outer surface of the head body 11 from growing into whiskers.

[0041] <Embodiment 2> Next, a second embodiment of the present disclosure will be described with reference to Figure 5. The nozzle head 40 of the second embodiment has a nozzle 45 configured differently from that of the first embodiment. Since the other configurations are the same as those of the first embodiment, the same components are denoted by the same reference numerals, and a description of the structure, operation, and effects will be omitted.

[0042] The nozzle head 40 of this embodiment is configured to include a head body 41 and a plurality of nozzles 45. The head body 41 is configured from an inner tube 12 and an outer tube 42. The inner tube 12 is the same member as the inner tube 12 of embodiment 1. The outer tube 42 is a stainless steel member having a cylindrical shape concentric with the inner tube 12. The outer tube 42 functions as a spinning electrode 43. The outer tube 42 has a plurality of female screw holes 44 formed therein that penetrate the outer tube 42 in the radial direction.

[0043] The nozzle 45 is a separate member from the outer tube. The nozzle 45 is a single component having a cylindrical mounting portion 46 with a male thread portion 47 formed on its outer circumferential surface, and a cylindrical protrusion portion 48 concentric with the mounting portion 46. The central holes of the mounting portion 46 and the protrusion portion 48 are spaces with a constant inner diameter and a circular cross section. The outer circumferential surface of the protrusion portion 48 is frustoconical, similar to the protrusion portion 48 of the first embodiment.

[0044] The nozzle 45 is attached to the outer tube 42 (head main body 41) by screwing the male screw portion 47 into the female screw hole 44. The nozzle 45 can be removed from the head main body 41 (outer tube 42) by loosening the male screw portion 47 from the female screw hole 44. The central hole of the attachment portion 46 and the protrusion portion 48 that constitute the nozzle 45 functions as a spinning hole 49 for spraying the spinning solution L (not shown). The nozzle 45 can be attached and detached to the head main body 41 by screwing, so maintenance of the nozzle 45 is easy. Furthermore, it is possible to replace only the nozzle 45.

[0045] <Embodiment 3> Next, a third embodiment of the present disclosure will be described with reference to Figure 6. The nozzle head 50 of the third embodiment has a nozzle 55 configured differently from that of the first embodiment. Since the other configurations are the same as those of the first embodiment, the same components are denoted by the same reference numerals, and a description of the structure, operation, and effects will be omitted.

[0046] The nozzle 55 of this embodiment 3 is a part formed integrally with the stainless steel outer tube 52 that constitutes the head body 51. The nozzle 55 has a spinning hole 57 and a protrusion 56. A plurality of circular through holes 54 are formed at the upper end of the cylindrical body 53. The nozzle 55 includes the opening edge of the through holes 54 in the cylindrical body 53. The protrusion 56 is a part that protrudes upward from the opening edge of the through holes 54 on the outer peripheral surface of the cylindrical body 53. The head body 51 functions as a spinning electrode 58.

[0047] The internal space of the protrusion 56 communicates with the through-hole 54 and forms the central hole of the nozzle 55. The entire central hole of the nozzle 55 functions as a spinning hole 57 with its axis facing up and down. The protrusion 56 is cylindrical with its axis facing up and down. The inner and outer peripheral surfaces of the protrusion 56 are both truncated cones. The inner diameter of the spinning hole 57 gradually decreases from the outer peripheral surface of the cylindrical main body 53 toward the protruding end of the protrusion 56 (the upper end of the nozzle 55). The radial thickness of the protrusion 56 is a constant dimension from the outer peripheral surface of the cylindrical main body 53 to the protruding end of the protrusion 56. In a cross section obtained by cutting the protrusion 56 horizontally, the cross-sectional area of the protrusion 56 gradually decreases from the outer peripheral surface of the cylindrical main body 53 toward the protruding end of the protrusion 56.

[0048] <Embodiment 4> Next, a fourth embodiment of the present disclosure will be described with reference to Figure 7. The nozzle head 60 of the fourth embodiment has a nozzle 65 configured differently from that of the first embodiment. Since the other configurations are the same as those of the first embodiment, the same components are denoted by the same reference numerals, and a description of the structure, operation, and effects will be omitted.

[0049] The nozzle 65 of the fourth embodiment is a part formed integrally with the head main body 61. The nozzle 65 has a protrusion 66 that rises upward from the opening edge of the through hole 62 formed in the head main body 61. The protrusion 66 constituting one nozzle 65 is composed of a plurality of protrusions 67 spaced apart in the circumferential direction. In the fourth embodiment, the number of protrusions 67 constituting one protrusion 66 (one nozzle 65) is three. The outer peripheral surface of each protrusion 67 is formed by a curved surface that forms a truncated cone. The outer peripheral surfaces of the three protrusions 67 form a common truncated cone. In a plan view, the inner peripheral surfaces of the three protrusions 67 form a part (arc) of a common circle. The curvature of the inner peripheral surface of the protrusion 67 is the same as the curvature of the inner peripheral surface of the through hole 62. In the nozzle 65, one spinning hole 68 is formed by the inner peripheral surface of one through-hole 62 and the inner peripheral surfaces of the three protruding pieces 67.

[0050] <Other Examples> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included within the technical scope of the present invention. In the first to fourth embodiments, the nozzle may be made of a metal other than stainless steel, or a conductive resin containing carbon fiber. In the first to fourth embodiments, the head main body may be made of an insulating material. In the first to fourth embodiments, the head main body is not limited to a double-tube structure consisting of an inner tube and an outer tube, and may be a single-tube structure. In the first to third embodiments, the protrusions are not limited to a cylindrical shape, but may also be in the shape of a square tube or the like. In the fourth embodiment, the number of projecting pieces that make up one protrusion may be two, or may be four or more. [Explanation of symbols]

[0051] A...Electrospinning device L: Spinning solution 10, 40, 50, 60... nozzle head 11, 41, 51, 61...Head body 21, 43, 58...Spinning electrodes 25, 45, 55, 65... nozzle 26, 49, 57, 68...Spinning holes 27,48,56,66…Protrusion 34...Collector electrode 35...Collection member

Claims

1. A head body, A nozzle that sprays a spinning solution from a spinning hole opening on the outer surface of the head body; a spinning electrode that generates a potential difference between itself and a collector electrode disposed near the collection member; A nozzle head configured to collect the spinning solution ejected from the nozzle in the state of being converted into ultrafine fibers by electrostatic force by the collecting member, The nozzle protrudes from the outer surface of the head body to allow contact with the spinning solution, and the nozzle head has a conductive protrusion that can be electrically connected to the spinning electrode.

2. 2. The nozzle head according to claim 1, wherein a cross-sectional area of the nozzle cut perpendicular to the direction in which the spinning solution is ejected decreases in a direction in which the protrusions protrude.

3. 3. The nozzle head according to claim 1, wherein the thickness of the protrusion decreases in a direction in which the protrusion protrudes.

4. 3. The nozzle head according to claim 1, wherein the protrusion has a cylindrical shape that is continuous around the entire periphery.

5. 3. The nozzle head according to claim 1, wherein the head body is made of a conductor and is electrically conductive with the protrusion.

6. 3. The nozzle head according to claim 1, wherein the nozzle is detachable from the head body by screwing.

7. 3. The nozzle head according to claim 1, wherein the nozzle is made of stainless steel.

8. A nozzle head; a collector electrode disposed in the vicinity of the collection member; The nozzle head is A head body, A nozzle that sprays a spinning solution from a spinning hole opening on the outer surface of the head body; A spinning electrode that generates a potential difference between itself and the collector electrode, The nozzle protrudes from the outer surface of the head body to allow contact with the spinning solution, and has a conductive protrusion that can be electrically connected to the spinning electrode, The spinning solution ejected from the nozzle is converted into ultrafine fibers by electrostatic force and collected by the collecting member.

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