JP7761875B2 - Nozzle head and spinning device - Google Patents

Description

The present invention relates to a nozzle head and a spinning device.

Patent Document 1 discloses a sheet manufacturing apparatus that produces a sheet composed of nanofibers using an electrospinning method. The sheet manufacturing apparatus includes an effluent body (solution tank), which is a long, hollow member, a supply electrode (spinning electrode), and a charging electrode. The effluent body contains the raw material liquid and the supply electrode. The effluent body has multiple outlet holes that connect the interior of the effluent body to its outer surface. The supply electrode supplies an electric charge to the raw material liquid. The charging electrode is located outside the effluent body and induces an electric charge in the raw material liquid by being at a higher or lower voltage than the supply electrode. The charged raw material liquid in the effluent body stretches from the outlet holes toward the charging electrode, becoming nanofibers that are then deposited on a sheet-like collecting member.

Japanese Patent Application Laid-Open No. 2014-224327

The efficiency of imparting a charge from the supply electrode to the raw material liquid increases as the contact area between the supply electrode and the raw material liquid increases. However, because the supply electrode of the sheet manufacturing apparatus in Patent Document 1 is a long, thin wire extending linearly along the longitudinal direction of the effluent body, the surface area of the supply electrode is small. As a result, the efficiency of imparting a charge from the supply electrode to the raw material liquid is low, making it impossible to improve spinning efficiency.

This disclosure was completed based on the above circumstances, and aims to provide a nozzle head, spinning method, and spinning device with high charge application efficiency.

The nozzle head of the present disclosure includes:
a cylindrical solution tank that can be filled with a spinning solution and has a spinning hole for spraying the spinning solution;
a spinning electrode disposed in the solution tank in contact with the spinning solution;
The spinning electrode is configured by forming the peripheral surface of the solution tank with a conductive material.

The spinning method of the present disclosure comprises:
By applying a voltage between the spinning electrode and the collector electrode, the spinning solution in the cylindrical solution tank is charged and sprayed from the spinning electrode side to the collector electrode side to form fibers,
A spinning method for obtaining a nonwoven fabric by collecting fibers formed from the spinning solution with a collecting member disposed between the spinning electrode and the collector electrode,
The spinning electrode is configured by forming the peripheral surface of the solution tank with a conductive material, and the spinning solution is sprayed from a spinning hole provided in the solution tank.

The spinning device of the present disclosure comprises:
The nozzle head;
a collector electrode disposed at a position spaced apart from the spinning electrode;
A collecting member disposed between the spinning electrode and the collector electrode,
By applying a voltage between the spinning electrode and the collector electrode, the spinning solution in the solution tank is charged and sprayed toward the collector electrode to form fibers,
The fibers formed from the spinning solution are collected by the collecting member to obtain a nonwoven fabric.

The nozzle head, spinning method, and spinning device disclosed herein can ensure a wide contact area between the spinning electrode and the spinning solution, thereby achieving high efficiency in imparting charge from the spinning electrode to the spinning solution.

1 is a side view showing the configuration of a spinning apparatus according to a first embodiment; Front view of spinning device Plan view of the nozzle head Front cross section of nozzle head A cross-sectional view of line A-A in FIG.

Here, a preferred example of the present disclosure will be described.
A nozzle head, a spinning method and a prevention device in which the spinning electrode is constituted by a cylindrical member made of metal.
- A nozzle head, a spinning method and a prevention device in which the spinning electrode is made of stainless steel.
- A nozzle head, spinning method and prevention device, in which the solution tank is configured to include an inner tube having a communicating hole and connected to a supply source of the spinning solution, and an outer tube surrounding the inner fitting, and at least one of the inner surface of the inner tube, the outer surface of the inner tube and the inner surface of the outer tube functions as the spinning electrode.
The nozzle head, spinning method and prevention device, wherein the outer tube is made of an insulating material.

[Embodiment 1]
A first embodiment of the present disclosure will be described with reference to FIGS. 1 to 5. Note that the present invention is not limited to these examples, but is defined by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included. In this first embodiment, with regard to the front-to-back direction, the positive direction of the X-axis in FIG. 1 is defined as the front. With regard to the left-to-right direction, the positive direction of the Y-axis in FIGS. 2 to 4 is defined as the right. The left-to-right direction and the width direction are used synonymously. With regard to the up-down direction, the positive direction of the Z-axis in FIGS. 1, 2, and 4 is defined as the up.

The spinning apparatus of this embodiment 1 is an electrospinning apparatus that spins ultrafine fibers 15 (nanofibers) at the nano level from a spinning solution 10 and continuously forms a fiber aggregate 16, such as a nonwoven fabric, made from these ultrafine fibers 15.

The spinning solution 10 contains a resin material that forms the ultrafine fibers 15 as a solute, dissolved or dispersed in a volatile solvent. Examples of solutes that can be used include synthetic resins such as polyacrylonitrile (PAN), polypropylene (PP), and polyethylene (PE). Examples of solvents that can be used include compounds such as N,N-dimethylacetamide (DMA), N,N-dimethylformamide (DMF), and tetrahydrofuran (THF).

As shown in FIG. 1, the spinning device includes a collection member 11, a collector electrode 17, a nozzle head 20, a DC power supply 31, a supply source 36 of the spinning solution 10, and a pump 38. The collection member 11 is formed from a flexible material, such as a collection fabric such as a nonwoven fabric. The collection member 11 is stretched horizontally and is fed forward from a feed roller 13 and taken up by a take-up roller 14. The region of the collection member 11 stretched horizontally between the rollers 13 and 14 is defined as the collection region 12. A fiber aggregate 16 composed of spun ultrafine fibers 15 is layered in a sheet form on the underside of the collection region 12 of the collection member 11. When using the fiber aggregate 16, the collection member 11 on which the fiber aggregate 16 is layered is pulled out from the take-up roll, and then the fiber aggregate 16 is peeled off from the collection member 11.

The collector electrode 17 is made of a conductive material such as metal and has a flat plate shape with its thickness oriented vertically. As shown in FIG. 1, the collector electrode 17 is disposed between the feed roller 13 and the take-up roller 14. The collector electrode 17 is disposed across the entire width of the collection member 11, facing closely to or in contact with the upper surface of the collection region 12. The collection region 12 of the collection member 11 moves forward along the lower surface of the collector electrode 17 (the surface facing the spinning electrode 35, described below).

The nozzle head 20 is a member that is elongated in the left-right direction overall, and is positioned so as to cover the entire width of the collection member 11 in the left-right direction. The nozzle head 20 is positioned below the collector electrode 17 and the collection area 12 of the collection member 11, and functions to spray the spinning solution 10 toward the collection area 12 of the collection member 11. The nozzle head 20 includes a solution tank 21 and a spinning electrode 35 (supply electrode).

As shown in Figures 4 and 5, the solution tank 21 includes an outer tube 22 with a circular cross section whose axis extends linearly in the left-right direction, and an inner tube 23 with a circular cross section whose axis extends linearly in the left-right direction. The inner tube 23 is concentrically arranged inside the outer tube 22. The interior of the inner tube 23 within the interior space of the solution tank 21 is defined as a first storage space 24. The space between the outer surface of the inner tube 23 and the inner surface of the outer tube 22 within the interior space of the solution tank 21 is defined as a second storage space 25. The first storage space 24 and the second storage space 25 are configured to supply and store the amount of spinning solution 10 required for spinning. For example, the outer diameter of the outer tube 22 can be 12 mm, the inner diameter of the outer tube 22 can be 10 mm, the outer diameter of the inner tube 23 can be 6 mm, and the inner diameter of the inner tube 23 can be 4 mm.

The outer tube 22 is formed, for example, from a solvent-resistant resin. Examples of solvent-resistant resins include synthetic resins such as fluororesin (PTFE). A through-hole 27 is formed in the left end wall 26 (one of the end walls) of the outer tube 22, allowing the end of the inner tube 23 to pass through in a liquid-tight manner. A conductive electrode plate 30 is liquid-tightly attached to a mounting hole 29 formed in the right end wall 28 of the outer tube 22. The outer surface of the electrode plate 30 is exposed to the outer surface of the right end wall 28 of the outer tube 22, and the inner surface of the electrode plate 30 is exposed to the inner surface of the right end wall 28 of the outer tube 22. The positive electrode of a DC power supply 31 is connected to the outer surface of the electrode plate 30. The negative electrode of the DC power supply 31 is connected to the collector electrode 17.

As shown in Figures 3 to 5, the outer tube 22 has a plurality of spinning holes 32 that connect the second storage space 25 to the outside of the solution tank 21 (outer tube 22). The multiple spinning holes 32 are holes for spraying the spinning solution 10 in the second storage space 25 upward toward the collection area 12 of the collection member 11. The multiple spinning holes 32 are provided at the highest part (top) of the outer tube 22. The multiple spinning holes 32 are aligned in a row in the axial direction of the outer tube 22, and are arranged at multiple locations spaced at regular intervals (e.g., 10 mm intervals). The opening shape of the spinning holes 32 is circular, and the diameter of the spinning holes 32 is, for example, 1.0 mm.

The inner pipe 23 is made of a conductive metal material. Specifically, the inner pipe 23 is made of a stainless steel pipe. The left end of the inner pipe 23 in the left-right direction passes through the through-hole 27 of the outer pipe 22 in a liquid-tight manner and is exposed to the outside of the solution tank 21. The downstream end of the supply pipe 37, described below, is connected to the left end of the inner pipe 23. The right end of the inner pipe 23 is liquid-tightly closed by a conductive closing plate 33. The closing plate 33 is in electrical contact with the electrode plate 30 attached to the outer pipe 22.

The inner tube 23 is formed with a plurality of communication holes 34 that connect the first storage space 24 to the second storage space 25. The communication holes 34 are holes that allow the spinning solution 10 supplied into the first storage space 24 to flow out into the second storage space 25. The communication holes 34 are provided at the highest part (top) of the inner tube 23. The communication holes 34 are aligned in a row in the axial direction of the inner tube 23, and are arranged at multiple locations spaced at regular intervals (e.g., 10 mm intervals). The spinning holes 32 and the communication holes 34 are arranged at different positions in the longitudinal direction (left-right direction) of the solution tank 21. Specifically, each communication hole 34 is located midway between adjacent spinning holes 32. When the solution tank 21 is cut along a vertical plane including the axis of the solution tank 21, the spinning holes 32 and the communication holes 34 are arranged within the cut surface.

The spinning electrode 35 is formed by the inner tube 23. In other words, the entire inner tube 23 functions as the spinning electrode 35. Specifically, the entire area of the inner surface of the inner tube 23 functions as the spinning electrode 35, which comes into contact with the spinning solution 10 stored in the first storage space 24 or flowing within the first storage space 24. The entire area of the outer surface of the inner tube 23 functions as the spinning electrode 35, which comes into contact with the spinning solution 10 stored in the second storage space 25 or flowing within the second storage space 25. The spinning electrode 35 is disposed over the entire length of the solution tank 21 in the left-right direction and is immersed in the spinning solution 10 in the solution tank 21. The spinning electrode 35 is connected to the positive electrode of the DC power source 31 via a conductive blocking plate 33 provided at the right end of the inner tube 23 and an electrode plate 30 provided on the right end wall portion 28 of the outer tube 22.

The supply source 36 is connected to the solution tank 21 via a supply pipe 37. The downstream end of the supply pipe 37 is connected to the left end of the inner pipe 23. A pump 38 is provided on the supply pipe 37. The spinning solution 10 stored in the supply source 36 is pumped into the first storage space 24 by driving the pump 38. The spinning solution 10 pumped into the first storage space 24 flows into the second storage space 25 through the communication hole 34 of the inner pipe 23, and is then sprayed upward and outside the solution tank 21 from the spinning hole 32 of the outer pipe 22.

Next, we will explain the method for producing the fiber aggregate 16. When the spinning device is started, the collection member 11 is sent at a constant speed from the delivery roller 13 to the take-up roller 14 while in contact with or close to the underside of the collector electrode 17. In the solution tank 21, the spinning solution 10 is supplied under pressure from the supply source 36 to the first storage space 24 and flows into the second storage space 25 through the communication hole 34. The spinning solution 10 comes into contact with the spinning electrode 35 while flowing through the first storage space 24 and the second storage space 25. When the DC power supply 31 is started and a voltage is applied between the spinning electrode 35 and the collector electrode 17, the entire spinning solution 10 in the solution tank 21 is positively charged.

An electric charge is induced and accumulated on the surface of the spinning solution 10 exposed to the outer periphery of the solution tank 21 in the spinning holes 32. These charges repel each other, and this repulsive force counteracts the surface tension of the spinning solution 10. An electrostatic force (Coulomb force) is generated along the electric field lines between the charged spinning solution 10 and the collector electrode 17. This electrostatic force overcomes the surface tension of the spinning solution 10, causing the charged spinning solution 10 to spray from the multiple spinning holes 32 as nano-level ultrafine fibers 15, which are then pulled toward the collector electrode 17 by the electrostatic force.

The ultrafine fibers 15 of the spinning solution 10 sprayed from the spinning holes 32 adhere to the lower surface of the collection area 12 of the collection member 11. Because the surface area of the nano-level ultrafine fibers 15 is large compared to their volume, the solvent in the ultrafine fibers 15 evaporates efficiently. The evaporation of the solvent reduces the volume of the ultrafine fibers 15, increasing the charge density of the ultrafine fibers 15. As the charge density increases, the repulsive force between the charged spinning solution 10 (the ultrafine fibers 15) increases, causing each ultrafine fiber 15 to split into even thinner ultrafine fibers 15. Through this process, the ultrafine fibers 15 are spun, and a fiber aggregate 16 made up of the ultrafine fibers 15 is collected on the lower surface of the collection member 11.

The spinning apparatus of this embodiment 1 includes a nozzle head 20 having a spinning electrode 35, a collector electrode 17 positioned at a distance from the spinning electrode 35, and a collection member 11 positioned between the spinning electrode 35 and the collector electrode 17. In the spinning method using this spinning apparatus, a voltage is applied between the spinning electrode 35 and the collector electrode 17, and the spinning solution 10 in the cylindrical solution tank 21 is charged and sprayed toward the collector electrode 17 to form fibers. The ultrafine fibers 15 made from this spinning solution 10 are then collected by the collection member 11 to obtain a nonwoven fabric.

The nozzle head 20 comprises a cylindrical solution tank 21 and a spinning electrode 35. The solution tank 21 can be filled with the spinning solution 10. The solution tank 21 has a spinning hole 32 for spraying the spinning solution 10 in the solution tank 21. The spinning electrode 35 is disposed in the solution tank 21 in contact with the spinning solution 10. The spinning electrode 35 is formed by forming the peripheral surface of the solution tank 21 from a conductive material.

The spinning electrode 35 has a larger surface area, i.e., a larger contact area with the spinning solution 10, compared to conventional electrodes consisting of a single, elongated, straight wire. Therefore, the efficiency of charge transfer from the spinning electrode 35 to the spinning solution 10 is superior to that of conventional electrodes. Therefore, the spinning device of this embodiment 1 can improve spinning efficiency.

The spinning electrode 35 is composed of a metallic cylindrical member (inner tube 23). Metal has higher rigidity than synthetic resin, and cylindrical members have higher bending rigidity than solid members. As such, the spinning electrode 35 of this embodiment 1 has high rigidity, which prevents variations in the thickness of fibers made from the spinning solution 10 caused by bending and deformation of the spinning electrode 35. Because the spinning electrode 35 is made of stainless steel, there is no risk of corrosion due to contact with the spinning solution 10.

The solution tank 21 has a multi-cylinder structure comprising an inner tube 23 and an outer tube 22. The inner tube 23 has multiple communication holes 34 and is connected to a supply source 36 of the spinning solution 10. The outer tube 22 coaxially surrounds the inner fitting. The inner and outer surfaces of the inner tube 23 function as a spinning electrode 35. The spinning solution 10 pressurized into the first storage space 24 of the inner tube 23 passes through the communication holes and flows into the second storage space 25 between the inner and outer tubes, thereby equalizing the pressure of the spinning solution 10. The spinning solution 10 in the solution tank 21 is charged by contacting the inner and outer surfaces of the inner tube 23 as it flows through the first storage space 24 and the second storage space 25. The outer tube 22 is made of an insulating material, preventing discharge from the outer surface of the outer tube 22.

<Other Examples>
The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments are also included within the technical scope of the present invention.
The cylindrical member constituting the spinning electrode may be made of a non-metallic material.
The spinning electrode may be a metal layer formed on the peripheral surface of the cylindrical member by plating, welding, or the like.
The spinning electrode may be made of a metal material other than stainless steel or a conductive resin material.
All of the circumferential surfaces, ie, the inner circumferential surface of the inner tube, the outer circumferential surface of the inner tube, and the inner circumferential surface of the outer tube, may function as spinning electrodes.
Only one of the inner peripheral surface of the inner tube, the outer peripheral surface of the inner tube, and the inner peripheral surface of the outer tube may function as a spinning electrode.
Only the inner peripheral surfaces of the inner tube and the outer tube may function as spinning electrodes.
Only the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube may function as spinning electrodes.
The outer tube may be made of an electrically conductive material.

10... spinning solution 11... collection member 15... ultrafine fiber (fiber)
17... Collector electrode 20... Nozzle head 21... Solution tank 22... Outer tube 23... Inner tube 32... Spinning hole 34... Communication hole 35... Spinning electrode 36... Supply source

Claims (5)

a cylindrical solution tank that can be filled with a spinning solution and has a spinning hole for spraying the spinning solution;
a spinning electrode disposed in the solution tank in contact with the spinning solution;
The spinning electrode is configured by forming the peripheral surface of the solution tank with a conductive material,
The solution bath is
an inner tube having a communication hole and connected to a supply source of the spinning solution;
an outer tube surrounding the inner tube,
A nozzle head in which at least one of the inner peripheral surface of the inner tube, the outer peripheral surface of the inner tube, and the inner peripheral surface of the outer tube functions as the spinning electrode. 2. The nozzle head according to claim 1, wherein the outer tube is made of an insulating material . 3. The nozzle head according to claim 1, wherein the spinning electrode is formed of a metallic cylindrical member . 4. The nozzle head according to claim 3, wherein the spinning electrode is made of stainless steel . The nozzle head according to any one of claims 1 to 4;
a collector electrode disposed at a position spaced apart from the spinning electrode;
A collecting member disposed between the spinning electrode and the collector electrode,
By applying a voltage between the spinning electrode and the collector electrode, the spinning solution in the solution tank is charged and sprayed toward the collector electrode to form fibers,
The spinning apparatus obtains a nonwoven fabric by collecting fibers formed from the spinning solution using the collecting member.