Method and apparatus for producing fiber sheet

Abstract

To provide a method and apparatus for producing a fiber sheet, capable of simultaneously suppressing charge repulsion between nozzles and reducing trim of a substrate between fiber sheets when forming a plurality of fiber sheets on the substrate using a plurality of nozzles in an electrospinning method.SOLUTION: The method for producing a fiber sheet in which raw material liquids are discharged from a plurality of nozzles and then fibers are deposited on a substrate by an electrospinning method, includes a pattern spinning step of forming a pattern in which a plurality of fiber sheets is arranged in a predetermined form on the substrate by: setting a conveying unit region including a plurality of planned fiber deposition regions on the substrate; intermittently conveying the conveying unit region in a machine flow direction and sequentially advancing the same to a plurality of spinning positions classified in the machine flow direction; and conducting spinning by the nozzles on the planned fiber deposition region at each of the spinning positions. In performing the pattern spinning step, the nozzles are arranged for each of the spinning positions to correspond to the planned fiber deposition regions; the minimum distance A between the nozzles is set larger than the minimum distance X between the plurality of fiber sheets arranged in the predetermined form to be finally obtained; the nozzles are arranged between the spinning positions so that they do not face an area of the fiber sheet formed at the previous spinning position; and the spun fibers are deposited in different planned fiber deposition regions in the conveying unit region at each of the spinning positions, thereby forming a pattern in which the plurality of fiber sheets is positioned in the predetermined form.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method and an apparatus for producing a fibrous sheet. [Background technology]

[0002] As a method for producing a fiber sheet, the electrospinning method is known. In the electrospinning method, a high voltage is applied to a raw material liquid (a solution or melt of a resin that is the raw material of the fiber) to spin and deposit ultrafine fibers (for example, fibers on the nanometer order) to form a fiber sheet. Several techniques related to this electrospinning method have been proposed so far. For example, the manufacturing method described in Patent Document 1 describes a technique for controlling the deposition state of fibers by changing the distance between a collector electrode disposed opposite a discharge portion of the raw material liquid and a substrate. Patent Document 2 describes a fiber sheet manufacturing device using multiple nozzles. In this manufacturing device, from the viewpoint of making the basis weight distribution in the fiber sheet uniform and suppressing uneven fiber distribution even when multiple types of fibers are mixed, different charges are applied to the raw material liquid discharged from each nozzle by multiple power sources. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-167641 A [Patent Document 2] Patent Publication No. 2022-028029 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, in a method for producing a fiber sheet by electrospinning, it has been considered to form a plurality of fiber sheets at a predetermined interval on a substrate using a plurality of nozzles (pattern spinning). When performing this pattern spinning, the applied voltage causes charge repulsion between fibers spun from adjacent nozzles, which may make it difficult to spin the fibers at a desired position on the substrate. This charge repulsion can be suppressed by increasing the nozzle interval. However, this means that the interval between the fiber sheets formed on the substrate is increased, and more of the substrate remains (hereinafter referred to as trim) after the plurality of fiber sheets are cut out. From the viewpoint of forming a plurality of fiber sheets on a substrate well and efficiently, it is required to suppress both charge repulsion between the plurality of nozzles and the occurrence of trim.

[0005] In view of the above, the present invention relates to a fiber sheet manufacturing method and manufacturing apparatus that can simultaneously suppress charge repulsion between nozzles and reduce trim of the substrate between fiber sheets when forming multiple fiber sheets on a substrate using multiple nozzles in an electrospinning method. [Means for solving the problem]

[0006] The present invention provides a method for producing a fiber sheet by discharging a raw material liquid from a plurality of nozzles and depositing fibers on a substrate by an electrospinning method, the method comprising a pattern spinning step of setting a transport unit area including a plurality of planned fiber deposition areas on the substrate, intermittently transporting the transport unit area in a machine flow direction to sequentially advance to a plurality of spinning positions separated in the machine flow direction, and performing spinning on the planned fiber deposition areas with the nozzles for each of the spinning positions to form a mold on the substrate with a predetermined arrangement of a plurality of fiber sheets, and in performing the pattern spinning step, the nozzles are disposed for each of the spinning positions corresponding to the planned fiber deposition areas, and a minimum distance A between the nozzles is set to be greater than a minimum distance X between the plurality of planned fiber sheets finally obtained in the predetermined arrangement, and the nozzles are disposed between the spinning positions so as not to face an area of ​​the fiber sheet formed at a previous spinning position, and spun fibers are deposited in different planned fiber deposition areas in the transport unit area for each of the spinning positions to form a mold on the substrate with the predetermined arrangement of the plurality of fiber sheets.

[0007] The present invention also provides a fiber sheet manufacturing device comprising: an electrospinning apparatus including a plurality of nozzles for ejecting a raw material liquid, a counter electrode arranged opposite the plurality of nozzles and generating an electric field between the nozzles, and a space into which a base material can be introduced between the plurality of nozzles and the counter electrode; a mechanism for setting a transport unit area including a plurality of planned fiber deposition regions in the base material, and intermittently transporting the transport unit area in a machine flow direction to sequentially advance the transport unit area to a plurality of spinning positions separated in the machine flow direction; the nozzles are arranged at each of the spinning positions corresponding to the planned fiber regions, and a minimum distance A between the nozzles is set to be greater than a minimum distance X between the plurality of fiber sheets finally obtained in the predetermined arrangement; the nozzles are arranged between the spinning positions so as not to face a region of a fiber sheet formed by spinning into the planned fiber deposition region at a previous spinning position; and the spun fibers are deposited in different planned fiber deposition regions in the transport unit area for each of the spinning positions to form a mold in which the plurality of fiber sheets are arranged in a predetermined arrangement. Effect of the Invention

[0008] According to the fiber sheet manufacturing method of the present invention, when a plurality of fiber sheets are formed on a substrate using a plurality of nozzles in an electrospinning process, it is possible to simultaneously suppress charge repulsion between the nozzles and reduce trim of the substrate between the fiber sheets. Also, according to the fiber sheet manufacturing apparatus of the present invention, the above manufacturing method can be suitably carried out. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic diagram illustrating a preferred embodiment of a manufacturing apparatus used in the method for manufacturing a fiber sheet according to the present embodiment. [Diagram 2] FIG. 2 is an explanatory diagram showing an example of a form in which fibers are spun in the space between a nozzle and a counter electrode. [Diagram 3] FIG. 2 is an explanatory diagram that illustrates a pattern spinning process (Specific Example 1). [Figure 4] FIG. 4 is an explanatory diagram that illustrates a schematic diagram of another example (specific example 2) of the pattern spinning process. [Diagram 5] 5(A) to 5(C) are explanatory views that typically show modified examples (specific examples 3 to 5) of the pattern spinning process shown in FIG. [Figure 6] FIG. 1A is an explanatory diagram that shows a schematic diagram of another example (Specific Example 6) of a pattern spinning process, and FIG. 1B is an explanatory diagram that shows a schematic diagram of a modified example (Specific Example 7) of FIG. [Figure 7] FIG. 1A is an explanatory diagram that shows a schematic diagram of another example (Example 8) of a pattern spinning process, and FIG. 1B is an explanatory diagram that shows a schematic diagram of a modified example (Example 9) of FIG. [Figure 8] FIG. 1A is an explanatory diagram that shows a schematic diagram of another example (Example 10) of a pattern spinning process, and FIG. 1B is an explanatory diagram that shows a schematic diagram of a modified example (Example 11) of FIG. [Figure 9] FIG. 9 is an explanatory diagram showing a pattern spinning process of Example 9 shown in FIG. 8(A) performed twice. [Figure 10] FIG. 4 is a plan view illustrating an example of a nozzle cleaning mechanism. [Figure 11]10A is a plan view showing the state in which the through hole of the nozzle cleaning mechanism and the nozzle are overlapped, and FIG. 10B is a plan view showing the state in which the nozzle cleaning part of the nozzle cleaning mechanism and the nozzle are overlapped. [Figure 12] FIG. 11 is a flow chart showing an example of a nozzle cleaning process. [Figure 13] FIG. 4 is a perspective view showing an example of a nozzle moving mechanism. [Figure 14] FIG. 2 is a perspective view showing a ring electrode and a side electrode used when performing multiple spinning at once using multiple nozzles, together with the nozzles. [Figure 15] FIG. 15 is an explanatory diagram illustrating an example of the action of the side electrode illustrated in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A preferred embodiment of the fiber sheet manufacturing method and manufacturing device of the present invention will be described below. In the manufacturing line, the direction in which the substrate is transported is called the machine direction (MD), and the direction perpendicular to the machine direction is called the cross direction (CD).

[0011] The method for producing a fiber sheet according to the present embodiment involves ejecting a raw material liquid from a plurality of nozzles and depositing fibers on a substrate by electrospinning. In the electrospinning method, a raw material liquid charged by application of a high voltage (e.g., 20 kV) is ejected from the tip of the nozzle by the action of an electric field, and is stretched into elongated fibers. The spun fibers are deposited as they are on the substrate to form a fiber sheet. The fiber diameter of the spun fibers can be, for example, on the order of nanometers.

[0012] In the fiber sheet manufacturing method of this embodiment, a pattern spinning step is carried out by the electrospinning method to form a mold (pattern) (hereinafter, simply referred to as a fiber sheet pattern) in which a plurality of fiber sheets are arranged on a substrate in a predetermined manner. In the fiber sheet pattern, the plurality of fiber sheets are formed at preset positions in a planar area on the substrate while being spaced from each other. The plurality of fiber sheets are arranged at least in the machine flow direction, and may be arranged in the machine flow direction and the width direction, or may be arranged in a direction intersecting the machine flow direction and the width direction. For example, the pattern may be a staggered pattern in which a plurality of rows in which a plurality of fiber sheets are arranged in the machine flow direction are arranged in the width direction, and the rows adjacent in the width direction are arranged at different arrangement pitches so that the machine flow direction positions of the fiber sheets do not overlap.

[0013] In the pattern spinning process, a transport unit area including a plurality of fiber deposition regions is set on the substrate. This transport unit area corresponds to the feed amount of the substrate described below, and the transport unit area is set based on the feed amount. Alternatively, the transport unit area may be set first, and the feed amount may be set accordingly. The fiber deposition region is an area where the fibers are deposited to form a fiber sheet, and is set at a position corresponding to the pattern of the fiber sheet. In addition, a plurality of spinning positions divided in the machine flow direction are set in the production line. Under this setting, the transport unit area on the substrate is intermittently transported in the machine flow direction to sequentially advance to the plurality of spinning positions. For each of the spinning positions that are sequentially reached, the nozzle performs spinning on the fiber deposition region. Through this intermittent transport, a plurality of fiber sheets are formed at predetermined positions (fiber deposition regions) on the substrate, and the pattern of the fiber sheet is obtained. In carrying out the pattern spinning process, the nozzles are arranged in a specific manner as described below. This makes it possible to simultaneously suppress charge repulsion between the nozzles and reduce trim of the substrate between the fiber sheets, thereby enabling a good formation of a fiber sheet pattern. The details of the specific nozzle arrangement will be described later together with the description of the manufacturing apparatus.

[0014] A preferred embodiment of a manufacturing apparatus for carrying out the fiber sheet manufacturing method of the present embodiment is, for example, as shown in Fig. 1. However, the apparatus is not limited to the one shown in Fig. 1, and other apparatus configurations can be appropriately changed as long as they include a specific arrangement of nozzles 1 described below.

[0015] The manufacturing apparatus 100 shown in FIG. 1 is an electrospinning apparatus that includes a plurality of nozzles 1 for ejecting a raw material liquid, a counter electrode 2 that is arranged opposite the plurality of nozzles 1 and generates an electric field between the nozzles 1, and a space 5 in which a substrate 4 can be introduced between the plurality of nozzles 1 and the counter electrode 2.

[0016] The substrate 4 may be made of various materials commonly used in this type of article, such as nonwoven fabric, film, sponge, woven fabric, knitted fabric, paper, mesh sheet, and laminates thereof. The substrate 4 may have various shapes as long as it can be transported in the machine flow direction and can perform the above-mentioned pattern spinning. For example, it may be a long continuous sheet or a single sheet. From the viewpoint of continuously producing the pattern of the fiber sheet 10 well and efficiently, the substrate is preferably a long continuous sheet. The long continuous sheet is preferably unwound from a roll of raw material. In the manufacturing apparatus 100 shown in FIG. 1, the substrate 4 is shown as a continuous sheet 46 unwound from a raw material roll 45.

[0017] The raw material liquid to be discharged is a raw material for fibers to be spun by the electrospinning method. For example, a resin solution in which a resin is dissolved in a solvent, or a resin melt in which a resin is melted to a temperature equal to or higher than its melting point can be used. The resin and solvent used in the resin solution may be any of various resins commonly used in electrospinning. For example, the resin may include one or more resins selected from polyester resin, acrylic resin, polystyrene resin, polyvinyl butyral resin, polyurethane resin, polyamide resin, polyimide resin, polyamideimide resin, etc. The polyester resin may contain one or more selected from polylactic acid, polyethylene terephthalate, polybutylene terephthalate, and the like. The acrylic resin may include one or more resins selected from polyacrylonitrile resin, polymethacrylic acid resin, and the like. The polyamide resin may include one or more selected from nylon and the like. Examples of the solvent include water, methanol, ethanol, 1-propanol, 2-propanol, hexafluoroisopropanol, 1-butanol, isobutyl alcohol, 2-butanol, 2-methyl-2-propanol, tetraethylene glycol, triethylene glycol, dibenzyl alcohol, 1,3-dioxolane, 1,4-dioxane, methyl ethyl ketone, methyl isobutyl ketone, methyl-n-hexyl ketone, methyl-n-propyl ketone, diisopropyl ketone, diisobutyl ketone, acetone, hexafluoroacetone, phenol, formic acid, methyl formate, ethyl formate, propyl formate, methyl benzoate, ethyl benzoate, propyl benzoate, and acetic acid. The solvent may include one or more selected from methyl, ethyl acetate, propyl acetate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, methyl chloride, ethyl chloride, methylene chloride, chloroform, o-chlorotoluene, p-chlorotoluene, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, trichloroethane, dichloropropane, dibromoethane, dibromopropane, methyl bromide, ethyl bromide, propyl bromide, acetic acid, benzene, toluene, hexane, cyclohexane, cyclohexanone, cyclopentane, o-xylene, p-xylene, m-xylene, acetonitrile, tetrahydrofuran, N,N-dimethylformamide, pyridine, and the like. The resin used in the resin molten liquid is a thermoplastic resin, and may include, for example, one or more selected from polyolefin resins, polyester resins, polyamide resins, vinyl polymers, acrylic polymers, nylon polymers, polyvinyl acetate, polyvinyl acetate-ethylene copolymers, and the like. The polyolefin resin may include one or more selected from polyethylene, polypropylene, ethylene-α-olefin copolymer, and the like. The polyester resin may contain one or more selected from polyethylene terephthalate, polybutylene terephthalate, polylactic acid, liquid crystal polymer, and the like. The vinyl polymer may include one or more selected from polyvinyl chloride, polyvinylidene chloride, polystyrene, and the like. The acrylic polymer may include one or more selected from polyacrylic acid, polyacrylic acid esters, polymethacrylic acid, polymethacrylic acid esters, and the like. The nylon-based polymer may include one or more selected from nylon 6, nylon 66, and the like. The resin solution or the resin melt may contain various additives. The raw material liquid is held in a raw material supplying section (not shown) and can be supplied to the nozzle 1 in a constant amount in the raw material supplying section.

[0018] The nozzle 1 and the counter electrode 2 can have various commonly available structures and shapes. For example, the nozzle 1 and the counter electrode 2 can be made of a conductive material such as metal. The nozzle 1 itself can be a non-conductor with an electrode inside. The nozzle 1 has an opening at the tip thereof that serves as an outlet for the raw material liquid and can be appropriately set according to the fiber diameter (for example, on the order of nanometers) of the fiber to be spun. The counter electrode 2 can also have various commonly available structures, such as a cylindrical metal rod.

[0019] In the manufacturing apparatus 100 of this embodiment, the voltage application device that generates an electric field between the nozzle 1 and the counter electrode 2 and charges the raw material liquid can be any of various devices commonly used in the electrospinning method, without any particular restrictions. For example, as shown in FIG. 2, the voltage application device 3 may have a voltage application unit 31 such as a DC high-voltage power supply and an electric wire 32. The voltage application device 3 shown in FIG. 2 electrically connects the voltage application unit 31 to the nozzle 1 and the counter electrode 2 via the electric wire 32. In addition, the counter electrode 2 is grounded. This allows the nozzle 1 and the counter electrode 2 to have different polarities from each other by applying a voltage. Making the polarities different from each other means that, for example, when the polarity of the voltage applied to one is positive, the polarity of the voltage applied to the other is negative, or zero polarity without positive or negative.

[0020] The voltage application device 3 shown in FIG. 2 applies a positive voltage to the nozzle 1 and a negative voltage to the counter electrode 2. However, the present invention is not limited to this, and various application forms can be adopted. For example, a negative voltage may be applied to the nozzle 1 and a positive voltage may be applied to the counter electrode 2. Also, a positive or negative voltage may be applied to the nozzle 1 and the counter electrode 2 may have a zero polarity, or vice versa. The zero polarity is achieved, for example, by grounding the nozzle 1 or the counter electrode 2 in FIG. 2.

[0021] In the manufacturing apparatus 100, a voltage application device 3 applies voltages of opposite polarity to the nozzle 1 and the counter electrode 2, respectively, to form an electric field in a space 5 between the nozzle 1 and the counter electrode 2. This space 5 is an area into which the base material 4 can be introduced, and is an area where the raw material liquid L discharged from the nozzle 1 is spun into fibers.

[0022] In the space 5 where an electric field is formed (hereinafter also referred to as the electric field space), a potential difference is generated between the nozzle 1 and the counter electrode 2. At the tip of the nozzle 1, charges are collected on the surface of the droplets of the raw material liquid L, and the droplets are stretched by the electric repulsive force of the charges, and are deformed into a cone shape called a Taylor cone. When the electric repulsive force of the charges exceeds the surface tension of the raw material liquid L, the cone-shaped raw material liquid L is discharged from the tip of the nozzle 1 into the electric field space 5. The discharged raw material liquid L is charged, and is attracted toward the counter electrode 2 by an electric attraction (electrostatic attraction) based on the potential difference in the electric field space 5. At that time, the discharged raw material liquid L is influenced by various forces such as an external electric attraction (electrostatic attraction) based on the potential difference in the electric field space 5 as well as an electric self-repulsive force within the charged raw material liquid L, and gradually draws a spiral and repeatedly stretches to become a fiber 8, which is spun toward the substrate 4 on the counter electrode 2.

[0023] The manufacturing apparatus 100 of this embodiment has a mechanism (conveyance control unit) 91 that controls intermittent conveyance of the continuous sheet 46, which is the substrate 4. The conveyance control unit 91 controls the driving of a pair of conveyance rolls 101, 101 and a downstream pair of conveyance rolls 102, 102 of the manufacturing apparatus 100. In this way, the continuous sheet 46 is intermittently conveyed while applying tension to the continuous sheet 46. Note that the means for conveying the continuous sheet 46, which is the substrate 4, is not limited to the pair of conveyance rolls 101, 101 and the downstream pair of conveyance rolls 102, 102 shown in FIG. 1, but various means that can be normally used for sheet conveyance in a manufacturing line can be used. The manufacturing apparatus 100 of this embodiment also has a mechanism (spinning control section) 92 for controlling spinning in cooperation with the transport control section 91. The spinning control section 92 can control the start, temporary stop or stop of spinning by the nozzle 1, the counter electrode 2, the voltage application device 3 and the raw material supply section (not shown) in cooperation with the intermittent transport of the continuous sheet 46 by the transport control section 91.

[0024] The conveyance control unit 91 defines a plurality of fiber deposition regions 4G (4G1, . . . 4G) on the continuous sheet 46. n ) including the transport unit area 4W (4W1, . . . 4W n ) to set the The fiber deposition area 4G is an area where the fiber sheet 10 formed by depositing spun fibers is arranged. Therefore, the fiber deposition area 4G is arranged at least in the machine direction, and may be arranged in the machine direction and the width direction, or may be arranged in a direction intersecting the machine direction and the width direction, or may be arranged in a zigzag arrangement as described above, similar to the arrangement of the fiber sheet 10. This point will be described later with specific examples shown in Figures 3 to 8. In this case, a margin where the fiber sheet 10 is not formed may be arranged between adjacent fiber deposition areas 4G. The size of the planar area of ​​each fiber deposition area 4G includes the fiber sheet 10, and is determined taking into account the center point of the fiber deposition by the nozzle 1 and the spread of the fiber deposition. For example, it is appropriately set according to the spinning capacity of the nozzle 1 (ejection speed and flying range of the raw material liquid, etc.), the movable range of the nozzle 1, the distance between the nozzle 1 and the counter electrode 2, the shape and size of the planar area of ​​the fiber sheet to be formed, etc. In addition, the shape of the planar area of ​​each fiber deposition area 4G can be set in various ways. From the viewpoint of suppressing charge repulsion between the nozzles and enabling the setting of dense fiber deposition regions 4G, a square or rectangular shape is preferable. The planar shape of the fiber sheet 10 formed in each fiber deposition region 4G can be set in various ways, but is not limited to these. Examples include a circular shape, an elliptical shape, a rectangular shape, a polygonal shape, a sector shape, a teardrop shape, etc. The transport unit area 4W includes a plurality of such fiber deposition regions 4G, and is an area that defines a pattern in which a plurality of fiber sheets 10 obtained as a result of spinning are arranged in a predetermined manner. Therefore, the planar shape of the transport unit area 4W is set according to the number, size, arrangement, etc. of the fiber deposition regions 4G that constitute the pattern of the fiber sheet 10. In addition, the transport unit area 4W is divided into a plurality of areas (4W1, ...4W2) along the longitudinal direction (machine flow direction) of the continuous sheet 46, which is the base material 4. n In this embodiment, as long as the continuous sheet 46, which is the base material 4, continues to be unwound from the original roll 45, the transport unit area 4W is repeatedly set without interruption.

[0025] The transport control unit 91 sets a feed amount B for the intermittent transport of the continuous sheet 46 (substrate 4). The feed amount B coincides with the length of the transport unit area 4W in the machine flow direction. As described above, the transport unit area 4W may be set based on the feed amount B, or vice versa. If the length of the transport unit area 4W in the machine flow direction varies depending on the location in the width direction, the feed amount B sets the longest length. However, as described above, the transport unit area 4W is divided into multiple units (4W1, ...4W2) in the longitudinal direction (machine flow direction) of the continuous sheet 46, which is the substrate 4. n In this embodiment, from the viewpoint of setting the plurality of transport unit areas 4W seamlessly along the machine flow direction, it is preferable that the length of the transport unit area 4W in the machine flow direction is the same at any point in the width direction.

[0026] The conveyance control unit 91 is configured to divide a plurality of spinning positions S (S1, . . . S) on the production line into sections in the machine flow direction. n The spinning position S is a position where spinning is performed on the fiber deposition area 4G of the transport unit area 4W. The transport control unit 91 sets the spinning position S on the production line so as to coincide with the transport unit area 4W of the continuous sheet 46.

[0027] Under this setting, the conveyance control unit 91 intermittently conveys the conveyance unit area 4W in the machine flow direction at a feed amount B to a plurality of spinning positions S (S1, . . . S n For example, the conveying unit area 4W1 is controlled to move sequentially to the spinning positions S1, . . . S n 4W1, 4W2, 4W3, 4W4, 4W5, 4W6, 4W7, 4W8, 4W9, 4W10, 4W11, 4W12, 4W13, 4W14, 4W15, 4W16, 4W17, 4W18, 4W19, 4W20, 4W21, 4W22, 4W3 n is advanced to each of the spinning positions S in sequence, following the conveying unit area 4W1. The nozzle 1 advances to the spinning position S (S1, . . . S) in sequence under the instruction of the spinning control unit 92. n), spinning is performed in the fiber deposition area 4G. A fiber sheet 10 is formed in the fiber deposition area 4G by the spinning. In conjunction with this, the transport control unit 91 issues a command to resume transport. This moves the transport unit area 4W to the next spinning position. In this manner, transport of the transport unit area 4W, temporary suspension of transport, and resumption of transport are repeated to reach a plurality of set spinning positions S (S1, ...S n ) in order. In this way, a pattern spinning step P is carried out in which a pattern is formed in which a plurality of fiber sheets 10 are arranged in a predetermined manner.

[0028] In carrying out the pattern spinning step P, the nozzle 1 is arranged in a specific manner as described below. That is, the nozzle 1 is disposed in correspondence with the fiber deposition area 4G. More specifically, the spinning position S (S1, . . . S n ), a nozzle 1 for spinning fibers is arranged at each spinning position S (S1, . . . S n ) at each spinning position S (S1, . . . S n The nozzle 1 corresponding to the fiber deposition area 4G forms an electric field for the fiber deposition area 4G in the space 5 between the nozzle 1 and the counter electrode 2, as described above. Furthermore, there are several spinning positions S (S1, ... S n ), the nozzle 1 is positioned so as not to face the area of ​​the fiber sheet 10 formed by spinning into the fiber deposition area 4G at the previous spinning position S. In this way, the multiple spinning positions S (S1, . . . S n ), the spun fibers are deposited in different fiber deposition regions 4G in the transport unit region 4W to form the fiber sheet 1. That is, the plurality of spinning positions S (S1, . . . S n ) and spinning is performed in sequence, so that multiple fiber deposition regions 4G (4G1, . . . 4G) in the transport unit region 4W are formed. n) to form the fiber sheet 10, and finally obtain the above-mentioned pattern of the fiber sheet 10. As long as the continuous sheet 46, which is the substrate 4, continues to be unwound from the original roll 45, the transport unit areas 4W are repeatedly set without interruption, and the above-mentioned pattern of the fiber sheet 10 can be repeatedly manufactured.

[0029] The minimum distance A between the nozzles is set to be greater than the minimum distance X between the plurality of fiber sheets that are finally obtained in the predetermined arrangement (hereinafter, simply referred to as the minimum distance X). This relationship (A>X) will be described later with reference to Figs. 3 to 8. The minimum distance A between the nozzles is the distance between the central axes of the nozzles 1. The minimum distance A between the nozzles is the distance between the central axes of the nozzles 1. n ) means the closest distance between all the adjacent nozzles 1, 1 arranged at the spinning positions S (S1, ...S2). The distance between adjacent nozzles 1, 1 includes not only the distance between the nozzles 1, 1 arranged in the machine flow direction, but also the distance between the nozzles 1, 1 arranged in the width direction and the distance between the nozzles 1, 1 arranged in the diagonal direction intersecting the machine flow direction and the width direction. n For all the nozzles 1 arranged in the fiber deposition region 4G, adjacent nozzles 1, 1 are arranged at a distance equal to or greater than the minimum distance A between the nozzles. The distance between adjacent nozzles 1, 1 is preferably the distance when each nozzle 1 is arranged at the center of the fiber deposition region 4G. This also applies to the minimum distance A between the nozzles. The minimum distance X refers to the smallest distance between the center points of adjacent fiber sheets 10 in the pattern of the fiber sheet 10 finally obtained in one transport unit area 4W. The minimum distance X is determined from the distances between the center points of adjacent fiber sheets 10 in all directions, including the machine direction, the width direction, and the diagonal directions intersecting the machine direction and the width direction.

[0030] When the transport unit area 4W has a pattern in which the fiber deposition areas S (fiber sheet 10) are arranged in a row along the machine flow direction, the minimum distance X can also be understood as follows. In other words, the minimum distance X may be a distance (B / N) obtained by dividing the feed amount B of the intermittent transport of the base material 4 (continuous sheet 46) by the number N of fiber deposition regions 4G aligned in the machine flow direction contained in the transport unit area 4W. The feed amount B of the intermittent transport of the base material 4 (continuous sheet 46) is as described above. The number N of fiber deposition regions 4G aligned in the machine flow direction contained in the transport unit area 4W is also the number (cumulative number) of nozzles 1 required to form a fiber sheet 10 aligned in the machine flow direction. This number N is also the number of fiber deposition regions 4G transported along the machine flow direction at the feed amount B. If the number of fiber deposition regions 4G aligned in the machine flow direction in the transport unit area 4W varies depending on the location in the width direction, the maximum number is set. However, as described above, the transport unit area 4W is divided into multiple areas (4W1, ... 4W2) in the longitudinal direction (machine flow direction) of the continuous sheet 46, which is the substrate 4. n In this embodiment, from the viewpoint of setting a plurality of transport unit areas 4W seamlessly along the machine flow direction, it is preferable that the number of fiber deposition areas 4G arranged in the machine flow direction is the same at any position in the width direction.

[0031] The minimum distance A between the nozzles satisfies the above-mentioned (A>X) relationship, so that multiple spinning positions S (S1, ...S n For all the nozzles 1 arranged in the nozzle array 1, the distance between adjacent nozzles 1, 1 is made larger than the minimum distance X between the plurality of fiber sheets finally obtained in the predetermined arrangement. This ensures a good separation distance between the nozzles 1, 1, and effectively suppresses charge repulsion between the fibers spun from adjacent nozzles 1, 1, allowing the fibers to be well spun at a targeted position (fiber deposition area 4G) on the substrate 4 (continuous sheet 46). In other words, the fiber sheet 10 can be well formed in the fiber deposition area 4G.

[0032] The nozzle 1 is disposed so as not to face the area of ​​the fiber sheet 10 formed by spinning in the fiber deposition area 4G at the previous spinning position S. As a result, all of the fiber deposition areas 4G (4G1, . . . 4G) in the conveying unit area 4W are n ), multiple spinning positions S (S1, . . . S n ) on the production line, the spinning is performed in a distributed manner. Therefore, even if the number of fiber deposition regions 4G is increased and set closer to each other to reduce the trim of the base material 4 as much as possible, the above-mentioned relationship (A>X) is maintained by setting multiple spinning positions S (S1, . . . S n ) the nozzles 1 are disposed in a distributed manner so as to effectively suppress the charge repulsion between the fibers. This allows a mold (pattern) in which a plurality of fiber sheets 10 are arranged in a predetermined manner to be formed more densely and satisfactorily in the pattern spinning step P described above.

[0033] In the manufacturing apparatus 100 shown in FIG. 1, after forming a mold (pattern) in which a plurality of fiber sheets 10 are arranged in a predetermined manner, the process proceeds to a laser cutting process. In the laser cutting process, the fiber sheet 10 and the material (base material 4) of the continuous sheet 46 are cut out together at the outer edge of the fiber sheet 10 by, for example, a laser cutter 93 controlled by a conveyance control unit 91. The cut-out laminated sheet of the fiber sheet 10 and the base material 4 is conveyed to a product outlet. The remaining continuous sheet 46 is collected in a roll as a trim 49 via a conveyance path adjustment roll 48. This series of processes is repeated while the continuous sheet 46 is conveyed.

[0034] In this manner, in the fiber sheet manufacturing method of this embodiment, when a plurality of fiber sheets are formed on a substrate using a plurality of nozzles in an electrospinning process, it is possible to simultaneously suppress charge repulsion between nozzles and reduce trim of the substrate between the fiber sheets. Furthermore, the fiber sheet manufacturing apparatus 100 of this embodiment can suitably implement the above-mentioned manufacturing method.

[0035] In the fiber sheet manufacturing method and manufacturing apparatus of this embodiment, as described above, the pattern spinning step P can be performed better even if the fiber deposition areas 4G are arranged closer together. Therefore, it is possible to perform distributed spinning at the multiple spinning positions to form the fiber sheet 10 well in all of the fiber deposition areas 4G of the transport unit area 4W. Note that the fiber sheet manufacturing method and manufacturing apparatus of this embodiment are not limited to forming the fiber sheet 10 in all of the fiber deposition areas 4G of the transport unit area 4W, and it is also acceptable to form the fiber sheet 10 only in some of the areas.

[0036] The pattern spinning process under the above-mentioned (A>X) relationship will be described below with reference to specific examples shown in Figs. 3 to 8. In the specific examples shown below, for convenience of explanation, the minimum distance A between the nozzles and the feed rate B of the intermittent conveyance of the substrate 4 (continuous sheet 46) are shown based on the conveyance unit area 4W and the fiber deposition area 4G, but in reality, they are understood as values ​​set in the manufacturing device. In addition, the manufacturing method and manufacturing device of the fiber sheet of this embodiment are not limited to the specific examples below, and may widely include those that satisfy the requirements of the arrangement configuration of the nozzle 1 described above. Furthermore, in the specific examples shown in Figs. 3 to 8, for convenience of understanding the correspondence between the fiber sheet 10 and the spinning position S, the formed fiber sheet 10 is shown with a different pattern for each spinning position S, but this does not mean that the fiber sheet 10 itself is different.

[0037] In the specific example 1 shown in FIG. 3, each conveying unit area 4W (4W1, 4W2) of the continuous sheet 46 has two square fiber deposition areas 4G1, 4G2 arranged in the machine flow direction. Two spinning positions S1, S2 are set on the production line, and the length of each of the two spinning positions S1, S2 in the machine flow direction is set to match the length of each conveying unit area 4W in the machine flow direction (the length of the two fiber deposition areas 4G1, 4G2 combined in the machine flow direction). Nozzles 11 and 12 are arranged corresponding to the two spinning positions S1, S2, respectively. More specifically, at the spinning position S1, the nozzle 11 is arranged corresponding to the fiber deposition area 4G1 on the upstream side in the conveying unit area 4W, and at the spinning position S2, the nozzle 12 is arranged corresponding to the fiber deposition area 4G2 on the downstream side in the conveying unit area 4W. As a result, in each transport unit area 4W of the continuous sheet 46, spinning is performed in the fiber deposition area 4G1 at the spinning position S1, and spinning is performed in the fiber deposition area 4G2 at the spinning position S2. Note that Fig. 3 shows a state in which the transport unit area 4W1 has passed through the first spinning position S1 and finished spinning at the last spinning position S2, and shows a state in which the transport unit area 4W2 connected thereto has finished spinning at the first spinning position S1 (in the drawings of other specific examples below, each transport unit area 4W also shows a state in which spinning at each spinning position until reaching the illustrated spinning position S is completed). In this way, two spinnings are performed in a distributed manner at the two spinning positions S1 and S2, and the fiber sheets 10 are formed in all of the fiber deposition regions 4G1 and 4G2 of each conveying unit region 4W. This produces a pattern in which the two fiber sheets 10 are arranged in the machine flow direction.

[0038] In specific example 1, the minimum distance A between the nozzles is the distance between the nozzles 11 and 12. The nozzle 11 is located at the most upstream position of the spinning position S1, and the nozzle 12 is located at the most downstream position of the spinning position S2. Therefore, the minimum distance A between the nozzles corresponds to the length in the machine flow direction of three fiber deposition regions 4G as shown in FIG. The minimum distance X is the distance between the center points of the fiber sheets 10, 10 formed in the fiber deposition areas 4G (for example, 4G1 and 4G2) aligned in the machine direction at the spinning position S2, and corresponds to the length of one fiber deposition area 4G in the machine flow direction. The feed amount B of the intermittent conveyance of the base material 4 is the movement amount from the spinning position S1 to the spinning position S2 of the conveyance unit area 4W, and corresponds to the length of two fiber deposition areas 4G in the machine flow direction. The number N of fiber deposition areas 4G aligned in the machine flow direction included in the conveyance unit area 4W is the number (2) of fiber deposition areas 4G1, 4G2 aligned in the machine flow direction. The aforementioned distance (B / N) corresponds to the length of one fiber deposition area 4G in the machine flow direction, and corresponds to the aforementioned minimum distance (X).

[0039] As described above, in Example 1, the minimum distance A between the nozzles is set wider than the above-mentioned (X). Moreover, spinning is performed in a distributed manner at the two spinning positions S1 and S2 in sequence. This makes it possible to simultaneously suppress charge repulsion between the nozzles and reduce the trim of the substrate between the fiber sheets as described above, and to satisfactorily manufacture a pattern in which the two fiber sheets 10 are arranged in the machine flow direction as described above. Furthermore, as long as the continuous sheet 46, which is the substrate 4, continues to be unwound from the original roll 45, the transport unit area 4W is repeatedly set without interruption, and the above-mentioned pattern of the fiber sheet 10 can be repeatedly manufactured.

[0040] Specific examples 2 to 5 shown in Fig. 4 and Fig. 5(A) to (C) are configurations in which the number of fiber deposition regions 4G, the number of spinning positions S, and the number of nozzles 1 in Specific example 1 shown in Fig. 3 are increased to three. Specifically, each conveyance unit area 4W (4W1, 4W2, 4W3) of the continuous sheet 46 has three square fiber deposition regions 4G1, 4G2, 4G3 arranged in the machine flow direction. Three spinning positions S1, S2, S3 are set on the production line, and nozzles 11, 12, and 13 are arranged corresponding to the three spinning positions S1, S2, and S3, respectively.

[0041] In the specific example 2 shown in Fig. 4, at the spinning position S1, a nozzle 11 is arranged corresponding to the upstream fiber deposition area 4G1 in the transport unit area 4W. At the spinning position S2, a nozzle 12 is arranged corresponding to the central fiber deposition area 4G2 in the transport unit area 4W. At the spinning position S3, a nozzle 13 is arranged corresponding to the downstream fiber deposition area 4G3 in the transport unit area 4W. The three nozzles 11, 12, and 13 are arranged at equal intervals, and each separation distance corresponds to the length in the machine flow direction of the four fiber deposition areas 4G. This is the minimum distance A between the nozzles in the specific example 2. The minimum distance X is the distance between the center points of the fiber sheets 10, 10 formed in the fiber deposition areas 4G (for example, 4G1 and 4G2) aligned in the machine direction at the spinning position S3, and corresponds to the length of one fiber deposition area 4G in the machine flow direction. The feed amount B of the intermittent conveyance of the base material 4 is the movement amount from the spinning position S1 to the spinning position S2 of the conveyance unit area 4W. In other words, it corresponds to the length of three fiber deposition areas 4G in the machine flow direction. The number N of fiber deposition areas 4G aligned in the machine flow direction included in the conveyance unit area 4W is the number (3) of fiber deposition areas 4G1, 4G2, and 4G3 aligned in the machine flow direction. The aforementioned distance (B / N) corresponds to the length (B / N) of one fiber deposition area 4G in the machine flow direction, and corresponds to the aforementioned minimum distance (X). As described above, in Example 2, the minimum distance A between the nozzles is set wider than the above-mentioned (X). Moreover, spinning is performed in a distributed manner at three spinning positions S1, S2, and S3 in order. As a result, the same effect as in Example 1 can be obtained in Example 2.

[0042] In specific examples 3 to 5 shown in Figures 5(A) to (C), the arrangement of the nozzles 11, 12, and 13 at the spinning positions S1, S2, and S3 is changed from that of specific example 2 shown in Figure 4. That is, at each spinning position S1, S2, and S3, the facing relationship between the nozzles 11, 12, and 13 and the fiber deposition regions 4G1, 4G2, and 4G3 is changed so as not to face the region of the fiber sheet 10 formed at the previous spinning position. 5(A), the minimum distance A between the nozzles corresponds to the length in the machine flow direction of two planned fiber deposition areas 4G between the nozzle 12 corresponding to the downstream planned fiber deposition area 4G3 in the transport unit area 4W at the spinning position S2 and the nozzle 13 corresponding to the central planned fiber deposition area 4G2 in the transport unit area 4W at the spinning position S3. The minimum distance A between the nozzles is set wider than the above-mentioned minimum distance (X=B / N), i.e., the length in the machine flow direction of one planned fiber deposition area 4G. In the specific example 4 of FIG. 5(B), the minimum distance A between the nozzles corresponds to the length in the machine flow direction of two fiber deposition regions 4G between the nozzle 11 corresponding to the downstream fiber deposition region 4G3 in the transport unit region 4W at the spinning position S1 and the nozzle 12 corresponding to the central fiber deposition region 4G2 in the transport unit region 4W at the spinning position S2. The minimum distance A between the nozzles is set wider than the above-mentioned minimum distance (X=B / N), that is, the length in the machine flow direction of one fiber deposition region 4G. In the specific example 4, the separation distance between the nozzle 12 at the spinning position S2 and the nozzle 13 at the spinning position S3 is also the same as above, and the separation distance can also be set as the minimum distance A between the nozzles. 5(C), the minimum distance A between the nozzles corresponds to the length in the machine flow direction of two planned fiber deposition areas 4G between the nozzle 11 corresponding to the central planned fiber deposition area 4G2 in the transport unit area 4W at the spinning position S1 and the nozzle 12 corresponding to the upstream planned fiber deposition area 4G1 in the transport unit area 4W at the spinning position S2. The minimum distance A between the nozzles is set wider than the above-mentioned minimum distance (X=B / N), i.e., the length in the machine flow direction of one planned fiber deposition area 4G. As described above, in Examples 3 to 5 shown in Figures 5(A) to (C), the above-mentioned relationship (A>X) is maintained, and spinning is performed in a distributed manner at the three spinning positions S1, S2, and S3 in order. As a result, in Examples 3 to 5, the same effects as in Example 1 can be obtained.

[0043] In specific examples 6 and 7 shown in Figures 6(A) and 6(B), each transport unit area 4W (4W1, 4W2, 4W3) is formed by arranging two square fiber deposition areas 4G1 and 4G2 in the machine flow direction in parallel with two square fiber deposition areas 4G3 and 4G4 in the machine flow direction. The fiber deposition areas 4G1 and 4G2 and the fiber deposition areas 4G3 and 4G4 are shifted in the machine flow direction by one fiber deposition area. Therefore, the transport unit area 4W has a planar shape like a checkerboard pattern in which two rows are combined in a staggered manner. Three spinning positions S1, S2, and S3 are set on the production line, and four nozzles 11, 12, 13, and 14 are distributed among the three spinning positions S1, S2, and S3.

[0044] 6(A), at the spinning position S1, the nozzle 11 and the nozzle 12 are arranged corresponding to the upstream fiber deposition regions 4G1 and 4G3 in the transport unit region 4W. At the spinning position S2, the nozzle 13 is arranged corresponding to the downstream fiber deposition region 4G4 in the transport unit region 4W, and at the spinning position S3, the nozzle 14 is arranged corresponding to the downstream fiber deposition region 4G2 in the transport unit region 4W. The distance between the nozzles 11 and 12 and the distance between the nozzles 13 and 14 are the same and are the length of the diagonal of a square constituting one fiber deposition area 4G. This is the minimum distance A between the nozzles in Example 6. The minimum distance X is the distance between the center points of the fiber sheets 10, 10 formed in the fiber deposition areas 4G (for example, 4G1 and 4G2) arranged in the machine direction at the spinning position S3, and corresponds to the length of one fiber deposition area 4G in the machine flow direction. The feed amount B of the intermittent transport of the base material 4 is the movement amount from the spinning position S1 to the spinning position S2 of the transport unit area 4W. Even if the transport unit areas 4W are arranged in a staggered checkerboard pattern as described above, it corresponds to the length of two fiber deposition areas 4G in the machine flow direction as a whole. The number N of fiber deposition areas 4G arranged in the machine flow direction included in the transport unit area 4W is the number (2) of fiber deposition areas 4G1 and 4G2, or 4G3 and 4G3 arranged in the machine flow direction. The above-mentioned distance (B / N) corresponds to the length (B / N) of one fiber deposition area 4G in the machine flow direction, and corresponds to the above-mentioned minimum distance (X). In this embodiment, since each fiber deposition area 4G is a square, the minimum distance X is also the distance between the centers of the fiber sheets 10, 10 formed in the fiber deposition areas 4G (for example, 4G2 and 4G3) arranged in the width direction at the spinning position S3, and in this case, the relationship is (X=B / N). If each fiber deposition area 4G is not a square, the distance between the center points of the fiber sheets 10, 10 formed in the fiber deposition areas 4G arranged in the machine direction and the width direction is different. In this case, the shorter distance between the center points of the fiber sheets 10, 10 in either the machine direction, the width direction, or the diagonal direction intersecting these is the minimum distance X. In this case, (X≦B / N) is satisfied, and the minimum distance X is set not to exceed the length (B / N) of one fiber deposition area 4G in the machine flow direction. As described above, in Example 6 shown in Fig. 6(A), the minimum distance A between the nozzles is set wider than the above-mentioned minimum distance (X). Moreover, spinning is performed in a distributed manner at three spinning positions S1, S2, and S3 in order. As a result, the same effect as Example 1 can be obtained in Example 6.

[0045] Specific Example 7 shown in FIG. 6(B) is different from Specific Example 6 in the arrangement positions of the nozzle 13 and the nozzle 14. Specifically, the nozzle 13 at the spinning position S2 is arranged corresponding to the downstream fiber deposition area 4G2 in the transport unit area 4W, and the nozzle 14 at the spinning position S3 is arranged corresponding to the downstream fiber deposition area 4G4 in the transport unit area 4W. In this case, the minimum distance A between the nozzles, the minimum distance X, the feed amount B, and the number N are the same as those in Specific Example 6, and have a relationship of (A>X=B / N). Moreover, spinning is performed in a distributed manner at the three spinning positions S1, S2, and S3 in order. Therefore, in Specific Example 7, the same effect as in Specific Example 1 can be obtained.

[0046] In the specific example 8 shown in Fig. 7(A), the number of fiber deposition regions 4G in each transport unit area 4W (4W1, 4W2) is increased by one from that in the specific example 6 shown in Fig. 6(A), and the number of fiber deposition regions 4G is increased by one for each row. Specifically, each transport unit area 4W is composed of a row of three square fiber deposition regions 4G1, 4G2, 4G3 arranged in the machine flow direction, a row of three square fiber deposition regions 4G4, 4G5, 4G6 arranged in the machine flow direction, and a row of three square fiber deposition regions 4G7, 4G8, 4G9 arranged in the machine flow direction, which are arranged in parallel in the width direction. These three rows are shifted from each other in the machine flow direction by one fiber deposition region, and each transport unit area 4W has a stepped planar shape in which three rows are combined in a staggered manner. Two spinning positions S1 and S2 are set on the production line. In addition, nine nozzles 11, 12, 13, 14, 15, 16, 17, 18, and 19 are distributed and arranged at the two spinning positions S1 and S2.

[0047] 7(A), at the spinning position S1, nozzles 11, 12, and 13 are arranged corresponding to fiber deposition regions 4G2, 4G5, and 4G8 at the center of each row in the transport unit area 4W. At the spinning position S2, nozzles 14, 15, and 16 are arranged corresponding to fiber deposition regions 4G1, 4G4, and 4G7 on the upstream side of each row in the transport unit area 4W, and nozzles 17, 18, and 19 are arranged corresponding to fiber deposition regions 4G3, 4G6, and 4G9 on the downstream side. The minimum distance A between the nozzles is the length of the diagonal of a square forming one intended fiber deposition area 4G between the nozzles 11 and 12. This also corresponds to the separation distance between the nozzles 12 and 13, between the nozzles 12 and 14, between the nozzles 13 and 15, between the nozzles 14 and 15, between the nozzles 15 and 16, between the nozzles 15 and 17, between the nozzles 16 and 18, between the nozzles 17 and 18, and between the nozzles 18 and 19. The minimum distance X is the distance between the center points of the fiber sheets 10, 10 formed in the fiber deposition regions 4G (for example, 4G1 and 4G2) aligned in the machine direction at the spinning position S2, and corresponds to the length of one fiber deposition region 4G in the machine flow direction. The feed amount B of the intermittent conveyance of the base material 4 is the movement amount from the spinning position S1 to the spinning position S2 of each conveyance unit region 4W. Even if the conveyance unit region 4W is in the form of a stepped staircase as described above, it corresponds to the length of three fiber deposition regions 4G in the machine flow direction as a whole. The number N of fiber deposition regions 4G aligned in the machine flow direction included in each conveyance unit region 4W is the number (three) of fiber deposition regions 4G1, 4G2 and 4G3, 4G4, 4G5 and 4G6, or 4G7, 4G8 and 4G9 aligned in the machine flow direction. The above-mentioned distance (B / N) corresponds to the length (B / N) of one fiber deposition area 4G in the machine flow direction, and corresponds to the above-mentioned minimum distance (X). In this embodiment, the minimum distance X is also the distance between the centers of the fiber sheets 10, 10 formed in the fiber deposition areas 4G (for example, 4G2 and 4G4) arranged in the width direction at the spinning position S3, and in this case, the relationship (X=B / N) is also satisfied. If each fiber deposition area 4G is not a square, as described above, the shorter distance between the center points of the fiber sheets 10, 10 in the machine direction, the width direction, or the diagonal direction intersecting these becomes the minimum distance X. In this case, too, (X≦B / N) is satisfied, and the minimum distance X is set not to exceed the length (B / N) of one fiber deposition area 4G in the machine flow direction. As described above, in Example 8 shown in Fig. 7(A), the minimum distance A between the nozzles is set wider than the above-mentioned minimum distance (X). Moreover, the spinning is performed in a distributed manner at two spinning positions S1 and S2 in turn. As a result, the same effect as Example 1 can be obtained in Example 8.

[0048] Specific Example 9 shown in FIG. 7(B) is different from Specific Example 8 in that the number of spinning positions is increased to three and the arrangement positions of the nozzles are changed. Specifically, at the spinning position S1, nozzles 11, 12, and 13 are arranged corresponding to the fiber deposition regions 4G1, 4G4, and 4G7 on the upstream side of each row in each transport unit area 4W. At the spinning position S2, nozzles 14, 15, and 16 are arranged corresponding to the fiber deposition regions 4G2, 4G5, and 4G8 in the center of each row in each transport unit area 4W. At the spinning position S3, nozzles 17, 18, and 19 are arranged corresponding to the fiber deposition regions 4G3, 4G6, and 4G9 on the downstream side of each row in each transport unit area 4W. In this case, the minimum distance A between the nozzles, the minimum distance X at the spinning position S3, the feed amount B, and the number N are the same as those in Specific Example 8, and have a relationship of (A>X=B / N). Moreover, spinning is carried out in a distributed manner in three spinning positions S1, S2, and S3 in order. Therefore, in Example 9, the same effects as in Example 1 can be obtained.

[0049] In a specific example 10 shown in Fig. 8(A), the positions in the machine flow direction of three rows of fiber deposition regions in the specific example 8 in Fig. 7(A) are aligned for each transport unit area 4W (4W1, 4W2). As a result, the planar shape of the transport unit area 4W is made square. Two spinning positions S1 and S2 are set on the production line. In addition, nine nozzles 11, 12, 13, 14, 15, 16, 17, 18, and 19 are distributed and arranged at the two spinning positions S1 and S2.

[0050] In the specific example 10 shown in FIG. 8(A), at the spinning position S1, the fiber deposition regions 4G1, 4G3, 4G7, and 4G are located at the four corners of the square transport unit region 4W. 9、 Furthermore, nozzles 11, 12, 13, 14, and 15 are arranged corresponding to fiber deposition region 4G5 at the central position. At spinning position S2, nozzles 16, 17, 18, and 19 are arranged corresponding to the remaining fiber deposition regions 4G2, 4G4, 4G6, and 4G8 in the transport unit region 4W. The minimum distance A between the nozzles is the length of a diagonal line of a square that defines one intended fiber deposition area 4G between the nozzles 11 and 15. This also corresponds to the distance between the nozzle 15 and the nozzles 12, 13, and 14, between the nozzle 17 and the nozzles 12, 14, 16, and 19, and between the nozzle 18 and the nozzles 16 and 19. The minimum distance X is the distance between the center points of the fiber sheets 10, 10 formed in the fiber deposition regions 4G (for example, 4G1 and 4G2) aligned in the machine direction at the spinning position S2, and corresponds to the length of one fiber deposition region 4G in the machine flow direction. The feed amount B of the intermittent conveyance of the base material 4 corresponds to the length of three fiber deposition regions 4G in the machine flow direction. The number N of fiber deposition regions 4G aligned in the machine flow direction included in the conveyance unit region 4W is the number (3) of fiber deposition regions 4G1, 4G2, and 4G3, 4G4, 4G5, and 4G6, or 4G7, 4G8, and 4G9 aligned in the machine flow direction. The aforementioned distance (B / N) corresponds to the length (B / N) of one fiber deposition region 4G in the machine flow direction, and corresponds to the aforementioned minimum distance (X). In this embodiment, the minimum distance X is also the distance between the centers of the fiber sheets 10, 10 formed in the fiber deposition regions 4G (e.g., 4G1 and 4G4) aligned in the width direction at the spinning position S2, and in this case too, the relationship is (X=B / N). If each fiber deposition region 4G is not a square, as described above, the minimum distance X is the shorter distance between the center points of the fiber sheets 10, 10 in the machine direction, the width direction, or a diagonal direction intersecting these. In this case too, (X≦B / N) holds, and the minimum distance X is set so as not to exceed the length (B / N) of one fiber deposition region 4G in the machine flow direction. As described above, in Example 10 shown in Fig. 8(A), the minimum distance A between the nozzles is set wider than the above-mentioned (X). Moreover, the spinning is performed in a distributed manner at two spinning positions S1 and S2 in turn. As a result, the same effect as Example 1 can be obtained in Example 10.

[0051] Specific example 11 shown in Fig. 8(B) is different from specific example 10 shown in Fig. 8(A) in that the number of spinning positions is increased to three and the arrangement position of the nozzles is changed. Specifically, at the spinning position S1, nozzles 11, 12, and 13 are arranged corresponding to the fiber deposition regions 4G1, 4G5, and 4G7 in the transport unit area 4W. At the spinning position S2, nozzles 14, 15, and 16 are arranged corresponding to the fiber deposition regions 4G3, 4G4, and 4G9 in the transport unit area 4W. At the spinning position S3, nozzles 17, 18, and 19 are arranged corresponding to the fiber deposition regions 4G2, 4G6, and 4G8 in the transport unit area 4W. In this case, the minimum distance A between the nozzles, the minimum distance X at the spinning position S3, the feed amount B, and the number N are the same as those of specific example 8, and have a relationship of (A>X=B / N). Moreover, spinning is carried out in a distributed manner in three spinning positions S1, S2, and S3 in order. Therefore, in Example 11, the same effects as in Example 1 can be obtained.

[0052] In the fiber sheet manufacturing method and manufacturing device of this embodiment, the minimum distance A between the nozzles is preferably 50 mm or more. This makes it possible to more effectively suppress charge repulsion under various spinning conditions in the arrangement of the multi-row nozzles in the planar region of the substrate 4. In addition, the raw material liquid discharged from the nozzle 1 flies in a spiral shape and becomes thin to become fibers. The fiber sheet 10 formed by the accumulation of these fibers is likely to spread in the fiber deposition region 4G, and is likely to be formed, for example, spreading in a circular shape from the position of the nozzle 1. In this formation process, by setting the minimum distance A between the nozzles to 50 mm or more under the above-mentioned relationship (A>X=B / N), it is possible to more effectively control the fiber sheets 10, 10 so that they do not overlap. For example, in FIG. 3, the length in the machine flow direction of the fiber deposition region 4G is A / 3 (A is the minimum distance between the nozzles), but as described above, the fiber sheet 10 is formed spreading in a circular shape on the fiber deposition region 4G. If the diameter of this circle is D, by setting D>A / 3, the fiber sheets 10, 10 can be effectively suppressed from overlapping each other. Although it depends on various spinning conditions, D is generally about several tens of mm. Therefore, by setting the minimum distance A between the nozzles to 50 mm or more, overlapping of the fiber sheets 10, 10 can be effectively suppressed. This makes it possible to more reliably perform spinning in the targeted fiber deposition region 4G, and more reliably produce fiber sheets 10 of various targeted shapes and basis weights.

[0053] From the above viewpoints, the minimum distance A between the nozzles is more preferably equal to or greater than 60 mm, and further preferably equal to or greater than 80 mm. Furthermore, from the viewpoint of more effectively suppressing trimming of the substrate 4, the minimum distance A between the nozzles is preferably 150 mm or less, more preferably 130 mm or less, and even more preferably 110 mm or less.

[0054] From the same viewpoint as above, the aforementioned minimum distance X is preferably equal to or less than 150 mm, more preferably equal to or less than 130 mm, and further preferably equal to or less than 100 mm. The aforementioned minimum distance X is preferably 60 mm or more, more preferably 70 mm or more, and even more preferably 80 mm or more, from the viewpoint of suppressing charge repulsion between adjacent fibers and more reliably performing spinning in the targeted fiber deposition region 4G.

[0055] In the fiber sheet manufacturing method and manufacturing device of this embodiment, the above-mentioned pattern spinning process P is performed multiple times for one conveying unit area 4W in the base material 4, and the necessary basis weight of the spun fiber can be spun in the multiple times. In one pattern spinning process P, as described above, the nozzle 1 is arranged so as not to face the area of ​​the fiber sheet 10 formed at the previous spinning position S. Therefore, one spinning is performed for each fiber deposition area 4G in the conveying unit area 4W. In contrast, by performing the above-mentioned pattern spinning process P multiple times, spinning is performed for each fiber deposition area 4G in the conveying unit area 4W the number of times of the above-mentioned pattern spinning process P. As a result, it is possible to more reliably manufacture a pattern of a fiber sheet 10 with a target basis weight while suppressing charge repulsion while densely packing the fiber deposition area 4G to reduce trim of the base material 4. It is also possible to more reliably manufacture a pattern of a fiber sheet 10 with a higher basis weight.

[0056] In the above-mentioned specific examples, one pattern spinning process P is performed by the following spinning units. That is, in specific example 1, the spinning units at two spinning positions S1 and S2 constitute one pattern spinning process P. In specific examples 2 to 9, the spinning units at three spinning positions S1, S2, and S3 constitute one pattern spinning process P. In specific example 10, the spinning units at two spinning positions S1 and S2 constitute one pattern spinning process P. In specific example 11, the spinning units at three spinning positions S1, S2, and S3 constitute one pattern spinning process P. In each of these specific examples, the pattern spinning step P of the spinning unit can be performed multiple times to spin the necessary basis weight of the spun fiber in the multiple times. In this case, the distance between the nozzle 1 at the end of the first pattern spinning step P and the nozzle 1 at the start of the second pattern spinning step P is also set to be equal to or greater than the minimum distance A between the nozzles in the above-mentioned relationship (A>X=B / N).

[0057] This point is illustrated in FIG. 9 for Example 10. In FIG. 9, the spinning units at the two spinning positions S1 and S2 shown in FIG. 8(A) are regarded as one pattern spinning process P, which is performed twice. In the first pattern spinning process P1, a target basis weight Y (g / m 2 ) Y / 2(g / m 2 In the second pattern spinning process P2, the fiber is deposited with a target basis weight Y (g / m 2 ) Y / 2(g / m 2 The two pattern spinning steps P (P1, P2) are performed to deposit fibers having a fiber basis weight Z (g / m 2 ) is set to "Y / 2" + "Y / 2", and the target basis weight Y (g / m 2 ) to reach

[0058] In the manufacturing method and manufacturing apparatus for a fiber sheet according to the present embodiment, during the pattern spinning step P, it is preferable to clean the nozzle 1 by a nozzle cleaning mechanism arranged in an area adjacent to the nozzle 1 on the conveying unit area 4W of the substrate 4 at the spinning position S without stopping the supply of the raw material liquid. This cleaning is for dealing with clogging of the tip of the nozzle 1. By performing this cleaning by the nozzle cleaning mechanism on the conveying unit area 4W, the movement of the nozzle 1 can be kept to a minimum, and a short time between spinnings (for example, the time of intermittent conveyance) can be effectively utilized. In addition, since cleaning is performed on the conveying unit area 4W without stopping the supply of the raw material liquid, the end cutting (trash shot) time after resuming spinning can be shortened, and rapid spinning can be continued.

[0059] An example of the nozzle cleaning mechanism is shown in Fig. 10. The nozzle cleaning mechanism 94 shown in Fig. 10 is used in the specific example 10 of Fig. 8(A). The nozzle cleaning mechanism 94 has through holes 941 arranged in accordance with the arrangement pattern of the nozzles 1 at the spinning position S on the production line, i.e., the arrangement pattern of the fiber deposition area 4G in the transport unit area 4W, and has a nozzle cleaning unit 942 arranged in an area other than the through holes 941. The nozzle cleaning unit 942 is formed of an elastic material such as a sponge so as not to damage the tip of the nozzle 1. Furthermore, it is preferable that the sponge surface that contacts the tip of the nozzle 1 is provided with lattice-shaped cuts (knurling). This allows the tip of the nozzle to be brought into contact with the sponge so as to be buried, and the tip of the nozzle can be cleaned more reliably. The nozzle cleaning unit 942 may contain a cleaning agent or the like. The nozzle cleaning mechanism 94 may also be provided with the through holes 941 and the nozzle cleaning unit 942 in a substrate 943 as shown in FIG. 10. The substrate 943 may have a support portion 944 connected to the frame portion 943. The support portion 944 supports the nozzle cleaning mechanism 94 independently of the nozzle 1 , and enables the nozzle cleaning mechanism 94 to move independently of the nozzle 1 .

[0060] The nozzle cleaning mechanism 94 shown in Fig. 10 is adapted to the arrangement pattern of the fiber deposition area 4G shown in the specific example 10 in Fig. 8(A), and has a size that covers the spinning position S1 and the spinning position S2. That is, it has a shape of two 3 x 3 lattices connected together. In the 3 x 3 lattice part 94A corresponding to the spinning position S1, the areas at the four corners and the center position are made into through holes 941, and the remaining area is made into a nozzle cleaning part 942. In the 3 x 3 lattice part 94B corresponding to the spinning position S2, the arrangement of the through holes 941 and the nozzle cleaning part 942 of the lattice part 94A is switched. The arrangement of the through hole 941 and the nozzle cleaning unit 942 in the nozzle cleaning mechanism 94 is not limited to that shown in FIG. 10, and can be appropriately set according to the arrangement pattern of the fiber deposition area 4G, that is, according to the form of the pattern spinning process P. The nozzle cleaning mechanism 94 shown in FIG. 10 is sized to cover a plurality of spinning positions S included in the pattern spinning process P, but is not limited to this, and may be sized to cover some of the spinning positions S. When the pattern spinning process P is performed multiple times, the nozzle cleaning mechanism 94 may be sized to cover a plurality of spinning positions S corresponding to the multiple pattern spinning processes P. In the nozzle cleaning mechanism 94 shown in FIG. 10, the through hole 941 is shown as a circular space, but is not limited to this and may be a space of various shapes. Furthermore, the nozzle cleaning unit 942 is shown as a rectangle, but is not limited to this and may be a space of various shapes.

[0061] As shown in FIG. 10, the nozzle cleaning mechanism 94 may be supported by the support part 944 independently of the nozzle 1 as described above, and may be movable independently of the nozzle 1. For example, as shown in FIG. 11(A), the nozzle 1 is placed in correspondence with the through hole 941, and fibers are spun toward the fiber deposition area 4G. Before and after the spinning process, as shown in FIG. 11(B), the nozzle cleaning mechanism 94 is moved to place the nozzle 1 in correspondence with the nozzle cleaning part 942, and cleaning is performed. If not all the nozzles 1 are placed in correspondence with the nozzle cleaning part 92 in one movement, it is preferable to move the nozzle 1 multiple times to place all the nozzles 1 in correspondence with the nozzle cleaning part 92 and perform cleaning. In this case, the nozzle 1 may be fixed at a position corresponding to the fiber deposition area 4G, or the nozzle 1 may be moved. In the latter case, it is preferable to arrange a movement mechanism for the nozzle 1 (specific examples will be described later) independently of the nozzle cleaning mechanism 94. By making the nozzle 1 movable, it is possible to perform nozzle cleaning in the blank space beside the fiber deposition area 4G of the substrate 4.

[0062] An example of a cleaning process for the nozzle 1 by the nozzle cleaning mechanism 94 is shown in FIG. As shown in Fig. 12, when nozzle solidification occurs (R1), the voltage application is stopped before and after the spinning process. This stops spinning. At that time, the supply of the raw material liquid is continued (step T1). Even if the supply of the liquid is continued, the raw material liquid is not discharged because the voltage application has been stopped. By continuing the supply of the liquid, spinning can be stably performed when it is restarted. Next, the nozzle cleaning mechanism 94 is moved so that the nozzle 1 overlaps the nozzle cleaning unit 942 (step T2). The nozzle 1 is lowered to contact or be inserted into the nozzle cleaning unit 942 (step T3). When cleaning is completed, the nozzle cleaning mechanism 94 is moved so that the through hole 941 overlaps the nozzle 1 (step T4), and the nozzle 1 and the fiber deposition area 4G are directly aligned. Next, the voltage application is resumed, and spinning is resumed by the electric field action of the space 5 (step T5). At the time of resumption, the nozzle 1 is aligned with a trim portion in the fiber deposition area 4G where a fiber sheet is not formed, and the end is cut off (step T6), and then a predetermined pattern spinning is performed. This ends the cleaning operation (R2).

[0063] 13, an example of the movement mechanism for the nozzle 1 is a nozzle movement mechanism 6 having a support part 61, a rail part 62 supported by the support part 61, a movable part 63 movable along the rail part 62 and having the nozzle 1 fixed thereto, a nozzle collection plate 63A held by the movable part 63, and a plurality of nozzles 1 attached to the nozzle collection plate 63A. By moving the movable part 63 along the rail part 62, the nozzle 1 can be moved within the fiber deposition planned region 4G of the substrate 4. At that time, it is more preferable that the rail part 62 is movable along the support part 61. The nozzle moving mechanism 6 shown in FIG. 13 is a nozzle moving mechanism 6 in which the nozzles 1 arranged in accordance with the specific example 10 in FIG. 8(A) are attached to a nozzle collecting plate 63A. A plurality of nozzles 1 are collected by the nozzle collecting plate 63A, and the nozzles 1 can be moved on the substrate 4 while maintaining the distance between the nozzles 1, 1 in the specific arrangement described above. The arrangement of the nozzles 1 in the nozzle moving mechanism 6 is not limited to that shown in FIG. 13, and can be appropriately set according to the arrangement pattern of the fiber deposition area 4G, that is, according to the form of the pattern spinning process P. In addition, the nozzle collecting plate 63A of the nozzle moving mechanism 6 shown in FIG. 13 is sized to cover a plurality of spinning positions S included in the pattern spinning process P, but is not limited thereto, and may be sized to cover some of the spinning positions S. When the pattern spinning process P is performed multiple times, the nozzle collecting plate 63A may be sized to cover a plurality of spinning positions S corresponding to the multiple pattern spinning processes P. At this time, it is preferable that the counter electrode 2 is also collected by a collecting board using a similar mechanism, and the nozzle 1 and the counter electrode 2 move synchronously while maintaining their coaxiality. This makes it possible to form a fiber sheet with a desired shape more precisely.

[0064] In the fiber sheet manufacturing method and manufacturing apparatus of the present embodiment, when a plurality of nozzles 1 are arranged as described above, it is preferable to have the following configuration from the viewpoint of further improving spinnability. That is, as shown in Fig. 14, it is preferable to arrange a ring electrode 81 so as to surround the tip of each nozzle 1. It is preferable that the ring electrode 81 is charged with a voltage of the same polarity as the nozzle 1 and the raw material liquid to be discharged. This can improve the straightness of spinning that directs the raw material liquid to be discharged toward the counter electrode 2. Also, as shown in Fig. 14, the electric field space 5 corresponding to the multiple nozzles 1 may be surrounded by a side electrode 82. The side electrode 82 is preferably charged with a voltage of the same polarity as the nozzles 1 and the raw material liquid to be discharged. This makes it possible to correct the trajectory of the fibers that tend to spread outward due to charge repulsion, as shown in Fig. 15, and improve the straightness of spinning. The ring electrode 81 and side electrode 82 described above can be used whether the substrate 4 is a single leaf or a continuous sheet. [Explanation of symbols]

[0065] 1 nozzle 4 Base material 4G Fiber deposition area 4W Transport unit area 8. Fiber 10 Fiber sheet L Raw material liquid S: Spinning positions in the machine direction (on the production line)

Claims

1. A method for producing a fiber sheet by discharging a raw material solution from a plurality of nozzles and depositing fibers on a substrate by an electrospinning method, a pattern spinning step in which a conveying unit area including a plurality of planned fiber deposition areas is set on the substrate, the conveying unit area is intermittently conveyed in a machine flow direction to sequentially advance to a plurality of spinning positions separated in the machine flow direction, and spinning is performed by the nozzles on the planned fiber deposition areas for each of the spinning positions to form a pattern on the substrate in which a plurality of fiber sheets are arranged in a predetermined manner, When carrying out the pattern spinning process, the nozzles are arranged at each of the spinning positions so as to correspond to the intended fiber deposition areas, and a minimum distance A between the nozzles is set to be wider than a minimum distance X between the plurality of predetermined arranged fiber sheets to be finally obtained; A method for manufacturing a fiber sheet, wherein the nozzle is positioned between the spinning positions so as not to face the area of ​​the fiber sheet formed at the previous spinning position, and spun fiber is deposited in a different fiber deposition area within the conveying unit area for each spinning position, thereby forming a mold in which the multiple fiber sheets are arranged in a predetermined manner.

2. The method for producing a fiber sheet according to claim 1 , wherein in the pattern spinning step, spinning is performed at the plurality of spinning positions to form the fiber sheet in all of the fiber deposition regions of the transport unit region.

3. 3. The method for producing a fiber sheet according to claim 1, wherein the minimum distance A between the nozzles is 50 mm or more.

4. 3. The method for producing a fiber sheet according to claim 1, wherein the minimum distance X between the plurality of fiber sheets finally obtained in the predetermined arrangement is 150 mm or less.

5. The method for producing a fiber sheet according to claim 1 or 2, wherein the pattern spinning step is carried out a plurality of times for one transport unit area of ​​the substrate, and a required basis weight of spun fiber is spun in the plurality of times.

6. 3. The method for producing a fiber sheet according to claim 1, wherein during the pattern spinning step, the nozzle is cleaned by a nozzle cleaning mechanism disposed in an area adjacent to the nozzle on the unit transport area of ​​the substrate at the spinning position without stopping the delivery of the raw material liquid.

7. an electrospinning apparatus including a plurality of nozzles for ejecting a raw material solution, a counter electrode disposed opposite the plurality of nozzles and generating an electric field between the nozzles and the counter electrode, and a space between the plurality of nozzles and the counter electrode into which a base material can be introduced, a mechanism for setting a conveying unit area including a plurality of planned fiber deposition areas on the substrate, and for intermittently conveying the conveying unit area in a machine flow direction to sequentially advance to a plurality of spinning positions separated in the machine flow direction, the nozzles are arranged at each of the spinning positions in correspondence with the predetermined fiber regions, and a minimum distance A between the nozzles is set to be wider than a minimum distance X between the plurality of predeterminedly arranged fiber sheets that are finally obtained, Between the spinning positions, the nozzle is arranged so as not to face the area of ​​the fiber sheet formed by spinning into the fiber deposition area at the previous spinning position, and spun fibers are deposited in different fiber deposition areas within the conveying unit area for each spinning position, thereby forming a mold in which the plurality of fiber sheets are arranged in a predetermined manner. Fiber sheet manufacturing equipment.

Images