Electrospinning device and electrospinning method

Abstract

To provide an electrospinning device and an electrospinning method capable of suppressing an occurrence of distortion in a belt-like body.SOLUTION: An electrospinning device comprises an electrospinning head, a take-up part and a conductor. The electrospinning head forms a sheet on a substrate by a discharge of an electrically charged raw material liquid. The take-up part includes a take-up core for taking up the belt-like body in which the sheet is formed on the substrate. The conductor is provided adjacent to the take-up core from at least one side in an axial direction of the take-up core, and is given an electric potential that differs from that of the electrically charged raw material liquid.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present invention relate to an electrospinning apparatus and an electrospinning method. [Background technology]

[0002] Some batteries, such as secondary batteries, have a separator that insulates the positive electrode from the negative electrode and is formed integrally with the positive electrode or the negative electrode. In manufacturing such batteries, a sheet is formed, for example, by an electrospinning method on the surface of an electrode (positive electrode or negative electrode) that is formed integrally with the separator. This sheet becomes the separator between the positive electrode and the negative electrode. After the separator is formed on the electrode, a winding unit winds up the strip with the separator formed on the electrode into a roll.

[0003] When a separator is formed on the surface of an electrode, for example, the separator is formed in a state in which it protrudes from the edge of the electrode (covering the end of the electrode). When the winding unit winds up such a strip, for example, it is required to prevent the separator portion protruding from the edge of the electrode from being wound into the electrode side, and to prevent the strip from being wound up in a distorted state. In other words, when the winding unit winds up the strip, it is required to prevent the edge of the strip from being wound up and to prevent distortion of the strip. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-174083 A [Patent Document 2] JP 2013-218801 A [Patent Document 3] JP 2012-528464 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide an electrospinning apparatus and an electrospinning method capable of suppressing the occurrence of distortion in a strip-shaped body. [Means for solving the problem]

[0006] According to an embodiment, the electrospinning device includes an electrospinning head, a winding unit, and a first conductor. The electrospinning head forms a sheet on a substrate by discharging a charged raw material liquid. The winding unit includes a winding core that winds up a strip of the substrate on which the sheet is formed. The first conductor is adjacent to the winding core from at least one side in the axial direction of the winding core, and is electrically connected to the charged raw material liquid. In opposite polarity The potential is given as [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an electrospinning apparatus according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing the positional relationship between a winding unit and a first conductor in an electrospinning device according to an embodiment. [Diagram 3] FIG. 3 is a schematic diagram showing an electrospinning apparatus according to a modified embodiment. [Figure 4] FIG. 4 is a schematic diagram showing the positional relationship between a take-up unit and a second conductor in an electrospinning device according to a modified embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment will be described with reference to the drawings.

[0009] (Embodiment) FIG. 1 is a schematic diagram showing an electrospinning apparatus 1 according to an embodiment. The electrospinning apparatus 1 is an apparatus for forming a fiber membrane on a substrate 10 by electrospinning (also called electric charge spinning or electric charge induced spinning). The substrate 10 is, for example, a sheet-shaped electrode. The substrate 10 is made of a material that is resistant to the raw material liquid. The substrate 10 is made of a conductive material. The substrate 10 may be made of, for example, aluminum.

[0010] As shown in FIG. 1, the electrospinning apparatus 1 includes an unwinding section 2, an electrospinning section 3, a winding section 6, and a conductor (first conductor) 7. A conveying path L is formed in the electrospinning apparatus 1. The substrate 10 is conveyed along the conveying path L from the unwinding section 2 to the winding section 6 through the electrospinning section 3. In the conveying path L, a conveying direction (indicated by arrows X1 and X2) along the conveying path L, a first direction as a width direction intersecting (perpendicular or substantially perpendicular) with the conveying direction, and a second direction (indicated by arrows Z1 and Z2) intersecting (perpendicular or substantially perpendicular) with both the conveying direction and the first direction are defined. In the conveying path L, the conveying direction in which the substrate 10 is conveyed, i.e., the direction toward the winding section 6, is the downstream side. In the conveying path L, the direction opposite to the conveying direction, i.e., the direction toward the unwinding section 2, is the upstream side. In FIG. 1, the arrow X1 side is the upstream side of the conveying path L, and the arrow X2 side is the downstream side of the conveying path L.

[0011] The unwinding section 2 includes an unwinding core 21. The unwinding core 21 is, for example, a reel. The unwinding core 21 extends along the first direction of the transport path L. The central axis c1 of the unwinding core 21 is aligned with the first direction of the transport path L. The unwinding core 21 is rotatable about the central axis c1. The substrate 10 is wound in a roll around the unwinding core 21. In the unwinding section 2, the unwinding core 21 rotates in the direction of the arrow R1 by driving a driving member (not shown) such as an electric motor. As a result, the substrate 10 wound around the unwinding core 21 is unwound in the transport direction of the transport path L. The unwound substrate 10 is supplied to the transport path L.

[0012] The electrospinning unit 3 includes one or more electrospinning heads 31. In the example of FIG. 1, the electrospinning unit 3 includes six electrospinning heads 31. Each of the electrospinning heads 31 includes a head body 32 and a nozzle 33 protruding from the head body. In each of the electrospinning heads 31, a raw material liquid, for example, in which an organic material is dissolved in a solvent, can be stored inside the head body 32. The raw material liquid is ejected from the nozzle 33 onto the substrate 10. The substrate 10 is disposed on the side from which the raw material liquid is ejected with respect to the electrospinning head 31. Each of the electrospinning heads 31 may be provided with one nozzle 33 or may be provided with a plurality of nozzles 33. A power source is provided in the electrospinning apparatus 1. In one example, the power source is a DC power source. The power source applies a voltage to the electrospinning head 31. The power source applies a voltage so that the nozzle 33 is charged to a predetermined polarity. The predetermined polarity may be positive or negative.

[0013] The organic substance used in the raw material liquid may be, for example, one or more selected from the group consisting of polyolefin, polyether, polyimide, polyketone, polysulfone, cellulose, polyvinyl alcohol, polyamide, polyamideimide, and polyvinylidene fluoride. Examples of polyolefin include polypropylene and polyethylene.

[0014] The voltage between each nozzle 33 of the electrospinning head 31 and the substrate 10 is appropriately set in response to the type of solvent and solute in the raw material liquid, the boiling point and vapor pressure curve of the solvent of the raw material liquid, the concentration and temperature of the raw material liquid, the shape of the nozzle 33, and the distance between the substrate 10 and the nozzle 33. In one example, the voltage (potential difference) applied between each nozzle 33 of the electrospinning head 31 and the substrate 10 is appropriately set between 1 kV and 100 kV. The discharge speed of the raw material liquid from each nozzle 33 of the electrospinning head 31 corresponds to the concentration, viscosity, and temperature of the raw material liquid, the voltage applied between each nozzle 33 of the electrospinning head 31 and the substrate 10, and the shape of the nozzle 33.

[0015] The winding section 6 includes a winding core 61. The winding core 61 is, for example, a reel. The winding core 61 extends along the first direction of the transport path L. The central axis c2 of the winding core 61 is aligned with the first direction of the transport path L. The winding core 61 is rotatable around the central axis c2. The winding core 61 includes an outer peripheral edge E1. The extension length of the outer peripheral edge E1 of the winding core 61 is the circumferential length at one end of the winding core 61 in the axial direction. In the winding section 6, the winding core 61 rotates in the direction of the arrow R2 by driving a driving member (not shown) such as an electric motor. As a result, the strip 12 in which the sheet 11 is formed on the substrate 10 is wound in a roll around the winding core 61. In addition, when the strip 12 is transported through the transport path L, the longitudinal direction of the strip 12 coincides or approximately coincides with the transport direction, the width direction of the strip 12 coincides or approximately coincides with the first direction of the transport path L, and the thickness direction of the strip 12 coincides or approximately coincides with the second direction of the transport path L.

[0016] The extension state of the conveying path L from the unwinding section 2 to the winding section 6 is not limited. In one example, the conveying path L extends along the horizontal direction. In another example, the conveying path L extends along the vertical direction. One or more bent or turned-back portions of the conveying path L may be provided between the unwinding section 2 and the winding section 6. The extension direction of the conveying path L may be changed at the bent or turned-back portions of the conveying path L. In one example, a turned-back portion of the conveying path L is provided between the electrospinning section 3 and the winding section 6. In another example, a turned-back portion of the conveying path L is provided inside the electrospinning section 3.

[0017] Fig. 2 is a schematic diagram showing the positional relationship between the winding unit 6 and the first conductor 7 in the electrospinning apparatus 1 of the embodiment. In Fig. 2, similarly to Fig. 1, the conveying direction, the first direction (indicated by the arrows Y1 and Y2), and the second direction in the conveying path L are defined, and the axial direction of the winding core 61 is defined. The axial direction of the winding core 61 coincides or approximately coincides with the first direction of the conveying path L.

[0018] The first conductor 7 is formed in a plate shape. The first conductor 7 is made of a conductive material. The first conductor 7 is adjacent to the winding core 61 from one side in the axial direction of the winding core 61, that is, from one side in the first direction of the transport path L. The first conductor 7 does not directly contact the winding core 61 (i.e., is in an electrically insulated state), and does not directly contact the strip 12 wound around the winding core 61 (is in an electrically insulated state). Therefore, a gap is formed between the winding core 61 and the first conductor 7, and between the strip 12 wound around the winding core 61 and the first conductor 7. The size of this gap can be set appropriately. In one example, the first conductor 7 is a metal plate having a pair of main surfaces. In this case, the first conductor 7 is placed in the electrospinning apparatus 1 with one of the pair of main surfaces facing the winding core 61 side in the axial direction of the winding core 61. In the axial direction of the winding core 61, the distance between the winding core 61 and the first conductor 7 is, for example, about 5 mm.

[0019] The outer peripheral edge E2 of the first conductor 7 is located on the outer peripheral side of the outer peripheral edge E1 of the winding core 61 over the entire circumference when projected from the axial direction of the winding core 61 (see FIG. 1). The first conductor 7 has a portion located on the outer peripheral side of the outer peripheral edge E1 of the winding core 61 over the entire circumference when viewed from the opposite side of the first conductor 7 with respect to the axial direction of the winding core 61. In one example, the winding core 61 is formed in a cylindrical or approximately cylindrical shape, and the first conductor 7 is formed in a disk or approximately disk shape. The winding core 61 and the first conductor 7 are arranged concentrically or approximately concentrically with each other. In this case, the total radial length of the first conductor 7 is greater than the total radial length of the winding core 61. The total peripheral length of the outer peripheral edge E2 of the first conductor 7 is greater than the total peripheral length of the outer peripheral edge E1 of the winding core.

[0020] It is preferable that the outer peripheral edge E2 of the first conductor 7 is located on the outer peripheral side of the outer peripheral edge E3 formed by the strip 12 wound around the winding core 61 over the entire circumference when projected in the axial direction of the winding core 61 (see FIG. 1). Since the strip 12 is wound around the winding core 61, the outer peripheral edge E3 formed by the strip 12 wound around the winding core 61 is located on the outer peripheral side of the outer peripheral edge E1. The position of the outer peripheral edge E3 in the radial direction of the winding core 61 is determined according to the amount of the strip 12 wound around the winding core 61. It is preferable that the outer peripheral edge E2 of the first conductor 7 is located on the outer peripheral side of the outer peripheral edge E3 over the entire circumference when projected in the axial direction of the winding core 61.

[0021] The first conductor 7 is given a potential different from that of the charged raw material liquid. In one example, the first conductor 7 is grounded, and the voltage of the first conductor 7 to ground may be 0V or approximately 0V. In another example, as shown in FIG. 1 etc., a voltage may be applied to the first conductor 7 by a power source 81. The first conductor 7 is preferably charged to a polarity opposite to the polarity to which the raw material liquid of the sheet 11 is charged. In one example, when the raw material liquid of the sheet 11 is charged to a positive polarity, the first conductor 7 is charged to a negative polarity. In another example, when the raw material liquid of the sheet 11 is charged to a negative polarity, the first conductor 7 is charged to a positive polarity. That is, the first conductor 7 is provided with a potential setting means for setting the potential of the first conductor 7 to a potential different from that of the charged raw material liquid. The potential setting means is, for example, a ground wire for grounding the first conductor 7, and in another example, a connection cable for connecting the first conductor 7 to a power source 81 that applies a voltage to the first conductor 7. In other words, the potential setting means can be configured as a potential setting cable connected to the first conductor 7.

[0022] In the electrospinning apparatus 1, the unwinding core 21 is rotated in the direction of the arrow R1 and the take-up core 61 is rotated in the direction of the arrow R2, whereby the substrate 10 is transported from the unwinding section 2 to the take-up section 6 through the transport path L. In the electrospinning section 3, the substrate 10 unwound from the unwinding core 21 is transported toward the take-up section 6.

[0023] In a state where the raw material liquid is stored inside each head body 32 of the electrospinning head 31, for example, by applying a voltage between the substrate 10 and each nozzle 33 of the electrospinning head 31, the raw material liquid is ejected from each nozzle 33 of the electrospinning head 31. That is, due to the potential difference between the nozzle 33 and the substrate 10, the charged raw material liquid is ejected toward the substrate 10. As a result, the raw material liquid stored inside the head body 32 is charged to the same polarity as the nozzle 33. The polarity of the voltage applied to the nozzle 33 may be positive or negative. In one example, the power source is a DC power source, and applies a positive voltage to the nozzle 33. Therefore, the raw material liquid is positively charged.

[0024] By ejecting the raw material liquid from the nozzle 33 toward the substrate 10, a part of the raw material liquid is deposited on the surface of the substrate 10 unwound from the unwinding section 2, and the deposited raw material liquid forms a sheet 11. In one example of FIG. 1, the raw material liquid is ejected onto both sides of the unwound substrate 10, and the sheet 11 is formed on both sides of the substrate 10. However, in one example, the raw material liquid may be ejected onto only one side of the unwound substrate 10. In this case, the sheet 11 is formed on only one side of the substrate 10. In this way, the electrospinning section 3 of this embodiment forms the sheet 11 by the electrospinning method. As a result, a strip 12 including the substrate 10 and the sheet 11 is formed. In the winding section 6, the strip 12 that has passed through the conveying path L is wound up on the winding core 61.

[0025] In one example, the sheet 11 is a separator that insulates between the positive and negative electrodes in the electrode group of the battery. In this case, one of the positive and negative electrodes in the electrode group is formed integrally with the separator, and the electrode (positive or negative electrode) formed integrally with the separator becomes the substrate 10. A fiber sheet 11 is formed on the surface of the electrode formed integrally with the separator by electrospinning or the like. When the separator integrated with the electrode (positive or negative electrode) is formed as the sheet 11, the sheet 11 is formed from a material having electrical insulation properties. In the electrode group of the battery, each of the positive and negative electrodes includes a current collector and an active material-containing layer that contains an active material. In each of the positive and negative electrodes, the active material-containing layer is supported on one or both sides of the current collector.

[0026] In the electrospinning apparatus 1, as described above, the winding core 61 of the winding unit 6 winds up the strip 12 in which the sheet 11 is formed on the substrate 10 unwound from the unwinding core 21 of the unwinding unit 2. At this time, the sheet 11 formed on the substrate 10 is formed beyond the edge of the substrate 10 extending along the conveying direction, that is, in a state in which the sheet 11 protrudes outward in the first direction of the conveying path L from the edge of the substrate 10 extending along the conveying direction. In this embodiment, the first conductor 7 is adjacent to the strip 12 from one side in the axial direction of the winding core 61. In addition, the first conductor 7 is given a potential different from that of the raw material liquid of the sheet 11. Therefore, a force corresponding to the potential difference acts between the first conductor 7 and the sheet 11. In one example, a voltage is applied to the first conductor 7 in a state in which the polarity is opposite to that of the raw material liquid of the sheet 11. That is, when the raw material liquid of the sheet 11 is positively charged, a voltage is applied such that the first conductor 7 becomes negatively charged. In this case, an attractive force acts between the web 12 and the first conductor 7. This causes a force to stretch the edge of the web 12 toward the first conductor 7. As a result, the edge of the web 12 is prevented from being wound inward in the first direction of the transport path L, and distortion of the web 12 wound around the winding core 61 of the winding unit 6 can be suppressed.

[0027] In the electrospinning apparatus 1, as described above, the first conductor 7 is adjacent to the winding core 61 from at least one side in the axial direction of the winding core 61, and is given a potential different from the potential of the charged raw material solution. Therefore, as described above, when the web 12 is wound by the winding core 61, the distortion occurring in the web 12 can be suppressed. That is, the winding section 6 can wind the web 12 in a state in which the curvature occurring in the web 12 is suppressed. Therefore, the circumferential length of the web 12 around the central axis c2 corresponding to the winding amount of the web 12 is suppressed from being lengthened and / or shortened due to the curvature of the web 12. As a result, when the wound web 12 is used, the web 12 can be stably unwound. In one example, the web 12 is an electrode-integrated separator. In this case, when an electrode group is manufactured, the wound electrode-integrated separator is unwound again to stably manufacture the electrode group.

[0028] In the electrospinning apparatus 1, the outer peripheral edge E2 of the first conductor 7 is preferably located on the outer peripheral side of the outer peripheral edge E1 of the winding core 61 over the entire circumference when projected from the axial direction of the winding core 61. By adjusting the size and position of the first conductor 7 in this manner, a force corresponding to the potential difference between the first conductor 7 and the web 12 can be applied when the winding core 61 winds up the web 12. As a result, distortion of the web 12 when the web 12 is wound up by the winding core 61 can be further suppressed.

[0029] In the electrospinning apparatus 1, it is preferable that the outer peripheral edge E2 of the first conductor 7 is located over the entire circumference on the outer peripheral side of the outer peripheral edge E3 formed by the web 12 taken up on the winding core 61 when projected from the axial direction of the winding core 61. By adjusting the size and position of the first conductor 7 in this manner, a force corresponding to the potential difference can be applied between the first conductor 7 and the web 12 when the winding core 61 is taking up the web 12. As a result, distortion occurring in the web 12 when the web 12 is taken up by the winding core 61 can be further suppressed.

[0030] (Modification) Fig. 3 is a schematic diagram of an electrospinning apparatus 1 according to a modified embodiment. Fig. 4 is a schematic diagram showing the positional relationship between the winding unit 6 and the conductor (second conductor) 9 in the electrospinning apparatus 1 according to a modified embodiment. In Figs. 3 and 4, as in Fig. 1, the conveying direction, the first direction and the second direction in the conveying path L, the axial direction of the unwinding core 21 of the unwinding unit 2, and the axial direction of the winding core 61 of the winding unit 6 are defined.

[0031] In the electrospinning apparatus 1 of this modification, the second conductor 9 is adjacent to the strip 12 from one side of the first direction of the transport path L along which the strip 12 is transported. In this modification, the second conductor 9 is disposed between the electrospinning section 3 and the winding section 6 along the transport path L. The second conductor 9 does not contact the strip 12 like the first conductor 7, so a gap is formed between the second conductor 9 and the strip 12. The size of the gap between the second conductor 9 and the strip 12 can be set appropriately. The second conductor 9 is, for example, a metal plate. In this case, the second conductor 9 has a pair of main surfaces, and is disposed in the electrospinning apparatus 1 with one of the pair of main surfaces facing the first direction of the transport path L. Note that a plurality of second conductors 9 may be provided in the electrospinning apparatus 1 along the transport path L.

[0032] The second conductor 9 has a dimension in the second direction of the transport path L that is larger than the dimension in the thickness direction of the strip 12. The second conductor 9 has a pair of edges E4, E5. The pair of edges E4, E5 extend along the transport direction of the transport path L. The edge E5 is disposed on the opposite side to the edge E4 in the second direction of the transport path L. The second conductor 9 has an edge E4 disposed on one side of the strip 12 in the second direction of the transport path L, and an edge E5 disposed on the opposite side of the strip 12 to the edge E4 in the second direction of the transport path L. The transport path L (strip 12) passes between the edges E4, E5 in the second direction of the transport path L. For the second conductor 9, the dimension in the second direction of the transport path L is not particularly limited, but it is preferable that the dimension in the transport direction is long enough to suppress the aforementioned wrapping of the edge of the strip 12 by a force corresponding to the potential difference between the second conductor 9 and the strip 12 acting on each other.

[0033] The second conductor 9 is given a potential different from that of the charged raw material liquid, similar to the first conductor 7. In one example, the second conductor 9 is grounded, and the voltage of the second conductor 9 to ground may be 0V or approximately 0V. In another example, a voltage may be applied to the second conductor 9 by a power source 82 shown in FIG. 3. It is preferable that the second conductor 9 is charged to a polarity opposite to that of the charged raw material liquid. In one example, when the raw material liquid of the sheet 11 is charged to a positive polarity, the second conductor 9 is charged to a negative polarity. In another example, when the raw material liquid of the sheet 11 is charged to a negative polarity, the second conductor 9 is charged to a positive polarity.

[0034] In this modification, the second conductor 9 is adjacent to the strip 12 on one side of the transport path L in the first direction of the transport path L. The second conductor 9 is given a potential different from that of the raw material liquid of the sheet 11. As a result, a force corresponding to the potential difference acts between the second conductor 9 and the sheet 11, as between the first conductor 7 and the sheet 11, and the edge of the strip 12 is prevented from being rolled inward in the first direction of the transport path L. This makes it possible to suppress distortion of the strip 12 wound around the winding unit 6. Also in this modification, the electrospinning apparatus 1 has the same configuration as the above-mentioned embodiment and the like, and therefore has the same actions and effects as the above-mentioned embodiment and the like.

[0035] The second conductor 9 is preferably provided on the side where the first conductor 7 is located in the first direction of the transport path L. By arranging in this manner, when the strip 12 is transported along the transport path L, the edge of the strip 12 is stretched to the side where the second conductor 9 is located, as described above. As a result, the strip 12 is transported to the winding unit 6 in a state where the edge of the strip 12 is prevented from being rolled inward in the first direction of the transport path L. Then, in the winding unit 6, the first conductor 7 is arranged on the side where the second conductor 9 is located in the first direction of the transport path L. Therefore, the edge of the strip 12 in a state where the roll-up is prevented by the second conductor 9 is further stretched by the first conductor 7 as described above. Therefore, the winding unit 6 can wind the strip 12 in a state where the curvature generated in the strip 12 is further prevented.

[0036] In the electrospinning device 1, in addition to the unwinding section 2, the electrospinning section 3, and the winding section 6, a stripping section (not shown) may be provided on the transport path L. The stripping section is provided, for example, between the electrospinning section 3 and the winding section 6. In this case, the stripping section is configured to strip the sheet 11 formed on the surface of the substrate 10, and a part of the sheet 11 is stripped off from the strip 12 by stripping off a part of the sheet 11 with the stripping section. As an example of such a stripping section, a unit equipped with a rotating brush driven by an electric motor or the like can be used. The sheet 11 is stripped off from the strip 12 by applying the rotating brush to the surface of the strip 12 in a rotating state. Such a configuration is used, for example, when the substrate 10 is an electrode (positive or negative electrode) and the sheet 11 formed from the raw material liquid is a separator. In this case, the separator is stripped off by applying the rotating brush to one end of the strip 12 in the width direction from one side of the strip 12 in the thickness direction. As a result, an electrode (positive or negative electrode) of the strip 12 is exposed at one end in the width direction.

[0037] When such a peeling unit is provided in the electrospinning apparatus 1, the first conductor 7 and the second conductor 9 are preferably provided on the side opposite to the side where the sheet 11 is peeled off by the peeling unit in the first direction of the transport path L. The peeling unit peels off the sheet 11 from the strip 12. Therefore, there is almost no sheet 11 on the edge of the strip 12 on the side where the sheet 11 is peeled off. By providing the first conductor 7 and the second conductor 9 on the side opposite to the side where the sheet 11 is peeled off in the width direction of the strip 12, winding up of the edge of the strip 12 by the winding unit 6 is appropriately suppressed.

[0038] When the electrospinning apparatus 1 includes a plurality of first conductors 7 and a plurality of second conductors 9, the first conductors 7 and the second conductors 9 can be appropriately arranged according to the use mode of the electrospinning apparatus 1. A plurality of first conductors 7 and a plurality of second conductors 9 may both be provided on one side of the conveying path L in the first direction. A plurality of first conductors 7 and a plurality of second conductors 9 may both be provided on both sides of the conveying path L in the first direction. In this example, a force toward both outsides in the first direction of the conveying path L is applied to the strip 12. Therefore, even if the sheet 11 is formed on both edges of the strip 12 formed along the conveying direction, winding by the winding unit 6 is appropriately suppressed.

[0039] The conveying path L may be provided with one or more guide rollers (not shown) for guiding the substrate 10 from the unwinding unit 2 to the winding unit 6. In this case, in the conveying path L, a guide roller is disposed at least one between the unwinding unit 2 and the electrospinning unit 3 and between the electrospinning unit 3 and the winding unit 6. The guide roller may be disposed inside the electrospinning unit 3. In addition, the sheet 11 formed on the surface of the substrate 10 may be dried between the electrospinning unit 3 and the winding unit 6.

[0040] In the electrospinning unit 3, the substrate 10 may be placed on a collector (not shown). Then, as described above, the raw material liquid is ejected from the nozzle 33 of the electrospinning head 31 toward the collector and the substrate 10. As a result, the raw material liquid is deposited on the surface of the substrate 10 placed on the collector, and a sheet 11 is formed on the surface of the substrate 10. In this case, even if the substrate 10 has electrical insulation properties, the sheet 11 of the raw material liquid can be formed on the surface of the substrate 10.

[0041] In the electrospinning unit 3, the portion to which the voltage is applied from the power source may be provided either in the supply source of the raw material liquid to the electrospinning head 31 or in the supply path between the supply source and the electrospinning head 31. The raw material liquid may be charged to the same polarity as the portion to which the voltage is applied from the power source. Thus, the charged raw material liquid is supplied to the electrospinning head 31.

[0042] The electrospinning apparatus of at least one of these embodiments includes an electrospinning head, a winding unit, and a first conductor. The electrospinning head forms a sheet on a substrate by discharging a charged raw material liquid. The winding unit includes a winding core that winds up a strip on which a sheet is formed on the substrate. The first conductor is adjacent to the winding core from at least one side in the axial direction of the winding core, and is given a potential different from that of the charged raw material liquid. This makes it possible to provide an electrospinning apparatus and an electrospinning method that can suppress the occurrence of distortion in the strip.

[0043] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. The following are additional notes. [1] An electrospinning head that forms a sheet on a substrate by ejecting an electrically charged raw material liquid; a winding section including a winding core for winding up a strip of the sheet formed on the substrate; and a first conductor adjacent to the winding core from at least one side in the axial direction of the winding core and given a potential different from that of the charged raw material liquid. An electrospinning apparatus comprising: [2] A power source is provided for applying a voltage to the first conductor so that the voltage has a polarity opposite to that of the charged raw material liquid. [1] The electrospinning apparatus according to the present invention. [3] The outer peripheral edge of the first conductor is located on the outer peripheral side of the outer peripheral edge of the winding core over the entire circumference when projected from the axial direction, The electrospinning apparatus according to [1] or [2]. [4] When projected from the axial direction, the outer peripheral edge of the first conductor is located on the outer peripheral side of the outer peripheral edge formed by the strip wound around the winding core over the entire circumference. [3] The electrospinning apparatus according to the present invention. [5] In the transport path through which the strip passes in the transport direction, a second conductor is further provided adjacent to the strip from at least one side in a first direction intersecting the transport direction and is given a potential different from that of the charged raw material liquid. The electrospinning apparatus according to any one of [1] to [4]. [6] A power source is provided for applying a voltage to the second conductor so as to have a polarity opposite to that of the charged raw material liquid. [5] The electrospinning apparatus according to the present invention. [7] The transport path is disposed in a state where it passes between a pair of edges of the second conductor in a second direction intersecting both the transport direction and the first direction. [5] or [6]. The electrospinning apparatus according to [1] or [2]. [8] Forming a sheet on a substrate by discharging the charged liquid material; A strip having the sheet formed on the substrate is wound around a winding core in a roll shape while the conductive material is adjacent to the strip. while the strip is wound around the winding core, the conductor is set to a potential different from that of the charged raw material liquid; The electrospinning method comprising: [Explanation of symbols]

[0044] 1...electrospinning apparatus, 31...electrospinning head, 6...winding section, 61...winding core, 7...first conductor, 81, 82...power source, 9...second conductor, 10...substrate, 11...sheet, 12...belt, E1 to E3...outer periphery, E4, E5...edge, L...conveying path.

Claims

1. an electrospinning head for forming a sheet on a substrate by discharging a charged raw material liquid; a winding section including a winding core for winding up a strip of the sheet formed on the substrate; a first conductor adjacent to the winding core from at least one side in the axial direction of the winding core and given a potential having a polarity opposite to that of the charged raw material liquid; An electrospinning apparatus comprising:

2. a power source that applies a voltage to the first conductor so that the voltage has a polarity opposite to that of the charged raw material liquid; 2. The electrospinning apparatus of claim 1.

3. The outer circumferential edge of the first conductor is located on the outer circumferential side of the outer circumferential edge of the winding core over the entire circumference when projected from the axial direction.

3. The electrospinning apparatus according to claim 1 or 2.

4. an outer circumferential edge of the first conductor is located on the outer circumferential side of an outer circumferential edge formed by the strip wound around the winding core, when projected from the axial direction; 4. The electrospinning apparatus of claim 3.

5. a second conductor is provided adjacent to the strip from at least one side in a first direction intersecting the transport direction in a transport path through which the strip passes in a transport direction, and the second conductor is provided with a potential having a polarity opposite to that of the charged raw material liquid; The electrospinning apparatus according to any one of claims 1 to 4.

6. a power source that applies a voltage to the second conductor so that the voltage has a polarity opposite to that of the charged raw material liquid; 6. The electrospinning apparatus of claim 5.

7. the transport path is disposed in a state of passing between a pair of edges of the second conductor in a second direction intersecting both the transport direction and the first direction; 7. The electrospinning apparatus according to claim 5 or 6.

8. forming a sheet on a substrate by discharging the charged liquid material; A strip having the sheet formed on the substrate is wound around a winding core in a roll shape while the conductive material is adjacent to the strip. while the strip is wound around the winding core, the conductor is set to a potential having a polarity opposite to that of the charged raw material liquid; The electrospinning method comprising:

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