US20200291544A1

US20200291544A1 - Head unit, electrospinning head, and electrospinning apparatus

Info

Publication number: US20200291544A1
Application number: US16/720,304
Authority: US
Inventors: Shizuo Kinoshita; Hiroaki Kobayashi; Kenya UCHIDA; Morihiro MACHIDA
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2019-03-12
Filing date: 2019-12-19
Publication date: 2020-09-17
Also published as: KR102287674B1; JP7242353B2; JP2020147863A; KR20200109248A; CN111690992A; CN111690992B

Abstract

According to one embodiment, an electrospinning head includes a plurality of head units and a coupling structure, and the plurality of head units are coupled to one another through the coupling structure. Each head unit includes a unit main body and a nozzle. Inside the unit main body, a hollow storing a raw material liquid is formed along a longitudinal axis. The nozzle is formed of a conductive material and provided on an outer circumferential surface of the unit main body. The nozzle ejects the raw material liquid supplied through the hollow of the unit main body. The coupling structure connects the plurality of head units in a state where the hollows of the unit main bodies communicate with one another.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-044870, filed Mar. 12, 2019; the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate to a head unit, an electrospinning head, and an electrospinning apparatus.

BACKGROUND

There exists an electrospinning apparatus which deposits fine fiber on a surface of a collection body or substrate via an electrospinning method (sometimes referred to as an “electric spinning method” or “charge-induced spinning method”) to form a film of fiber. The electrospinning apparatus includes an electrospinning head, including a head body and a nozzle. The electrospinning head is provided with a hollow (head flow passage) for storing a raw material liquid inside the head body, and the nozzle on an outer circumference surface of the head body. The raw material liquid is ejected from an ejection port of the nozzle toward the surface of the collection body or substrate to deposit the fiber on the surface of the collection body or substrate, via the application of a voltage between the electrospinning head and the collection body or substrate.
In the electrospinning apparatus described above, when fiber is deposited on a surface of a substrate having a large size in its width direction, a film of the fiber having a large size in its width direction may be formed via the electrospinning method. Even when a film of the fiber having a large size in its width direction is formed, an electrospinning apparatus is required to appropriately deposit the fiber on a surface of a substrate or the like, and appropriately form a film of the fiber. The electrospinning apparatus is also required to suppress the complexity of its configuration and its control system, and to suppress an increase in manufacturing costs and a reduction in productivity of its electrospinning head.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an example of an electrospinning apparatus according to a first embodiment;

FIG. 2 is a perspective diagram schematically showing an electrospinning head according to the first embodiment;

FIG. 3 is a schematic diagram showing the electrospinning head according to the first embodiment when viewed from a direction crossing the longitudinal axis of the head;

FIG. 4 is a cross-sectional diagram schematically showing the electrospinning head according to the first embodiment at a cross-section parallel or substantially parallel to the longitudinal axis of the head;

FIG. 5 is a cross-sectional diagram schematically showing the electrospinning head according to the first embodiment at a cross-section perpendicular or substantially perpendicular to the longitudinal axis of the head;

FIG. 6 is a perspective diagram schematically showing an electrospinning head according to a first modification;

FIG. 7 is a schematic diagram showing the electrospinning head according to the first modification when viewed from a direction crossing the longitudinal axis of the head;

FIG. 8 is a cross-sectional diagram schematically showing the electrospinning head according to the first modification at a cross-section parallel or substantially parallel to the longitudinal axis of the head;

FIG. 9 is a cross-sectional diagram schematically showing the electrospinning head according to the first modification at a cross-section perpendicular or substantially perpendicular to the longitudinal axis of the head;

FIG. 10 is a schematic diagram showing an electrospinning head according to a second modification in a state where head units are separated from each other;

FIG. 11 is a cross-sectional diagram schematically showing the electrospinning head according to the second modification at a cross-section parallel or substantially parallel to the longitudinal axis of the head;

FIG. 12 is a schematic diagram showing an electrospinning head according to a third modification when viewed from a direction crossing the longitudinal axis of the head;

FIG. 13 is a schematic diagram showing the electrospinning head according to the third modification when viewed from one side of the direction along the longitudinal axis; and

FIG. 14 is a schematic diagram showing an electrospinning head according to a fourth modification.

DETAILED DESCRIPTION

According to an embodiment, the head unit includes a unit main body and a nozzle. Inside the unit main body, a hollow configured to store a raw material liquid is formed along the longitudinal axis of the unit main body. The nozzle is formed of a conductive material and provided on an outer circumferential surface of the unit main body. The nozzle is configured to eject the raw material liquid supplied through the hollow of the unit main body. The head unit includes a coupling structure. The coupling structure is capable of coupling another head unit to the head unit, on at least one side of the head unit, in the direction along the longitudinal axis. The coupling structure couples a unit main body of another head unit to the unit main body in a state where the hollow of the unit main body communicates with a hollow of the unit main body of said another head unit. A head flow passage is then formed by the hollow of the unit main body and the hollow of said another head unit communicating with the hollow of the unit main body.
According to another embodiment, the electrospinning head includes a plurality of head units and a coupling structure, and the plurality of head units are arranged along the longitudinal axis. The plurality of head units are coupled to one another through the coupling structure. Each head unit includes a unit main body and a nozzle. Inside the unit main body, a hollow configured to store a raw material liquid is formed along the longitudinal axis. The nozzle is formed of a conductive material and provided on an outer circumferential surface of the unit main body. The nozzle is configured to eject the raw material liquid supplied through the hollow of the unit main body. The coupling structure connects the plurality of head units in a state where the hollows of the unit main bodies communicate with one another. A head flow passage is formed along the longitudinal axis by the hollows communicating with one another.
According to another embodiment, an electrospinning apparatus includes the electrospinning head, a supply source, and an electric power source. The supply source supplies a raw material liquid to the head flow passage of the electrospinning head. The electric power source applies a voltage to the electrospinning head.
Hereinafter, the embodiments will be described with reference to the drawings.

First Embodiment

FIG. 1 shows an example of an electrospinning apparatus 1 according to a first embodiment. As shown in FIG. 1, the electrospinning apparatus 1 includes an electrospinning head 2, a supply source (supply section) 3 of a raw material liquid, an electric power source 4, a collection body 5, and a controller 6.
FIGS. 2 to 5 respectively show the configuration of the electrospinning head 2. As shown in FIGS. 1 to 5, the electrospinning head 2 has a longitudinal axis C as a central axis, and extends along the longitudinal axis C. The electrospinning head 2 includes a head main body 11 and a plurality of nozzles 12 (four nozzles in the present embodiment). In the electrospinning head 2, as many connectors 13 as there are nozzles 12 are provided, and each nozzle 12 is connected to the head main body 11 via one corresponding connector 13. In the present embodiment, the head main body 11, nozzles 12 and connectors 13 are respectively formed of a conducting material.
The number of the nozzles 12 is not particularly limited. The connectors 13 are not necessarily provided, and each nozzle 12 may be directly connected to the head body 11. Furthermore, each of the head main body 11, nozzles 12, and connectors 13 is preferably formed of a material having resistance to a raw material liquid (to be described later), for example, stainless steel. Here, FIG. 2 is a perspective diagram and FIG. 3 shows a state where the electrospinning head is viewed from a direction crossing (perpendicular or substantially perpendicular to) the longitudinal axis C. FIG. 4 shows a cross-section parallel or substantially parallel to the longitudinal axis C, and FIG. 5 shows a cross-section perpendicular or substantially perpendicular to the longitudinal axis C.
The respective nozzles 12 are provided on an outer circumferential surface of the head main body 11. The outer circumferential surface of the head main body 11 extends around the longitudinal axis C and forms a part of an exterior surface of the head main body 11. The outer circumferential surface of the head main body 11 faces the side away from the longitudinal axis C, in a direction crossing the longitudinal axis C. In the present embodiment, the plurality of nozzles 12 are arranged at the same or substantially the same angular positions with respect to one another around the longitudinal axis C. For this reason, in the present embodiment, the plurality of nozzles 12 are arranged along the longitudinal axis C to form a nozzle row 15. Each nozzle 12 protrudes to the outer circumference side on the outer circumferential surface of the head main body 11.
Inside the head main body 11, a head flow passage 16 is formed along the longitudinal axis C. In the present embodiment, the head flow passage 16 is formed coaxially or substantially coaxially with the head main body 11, and the central axis of the head flow passage 16 is formed coaxially or substantially coaxially with the longitudinal axis C. Also, the head flow passage 16 is formed across the entirety or the majority of the head main body 11 in the direction along the longitudinal axis C. Therefore, in the present embodiment, the head main body 11 is formed into a cylindrical shape, provided with the head flow passage 16 as an internal hollow.
In the electrospinning head 2, as many nozzle flow passages 17 as there are nozzles 12 are formed, and one corresponding nozzle flow passage 17 is formed inside of each nozzle 12. Each nozzle flow passage 17 communicates with the head flow passage 16 and extends toward the outer circumference side of the head main body 11 from the head flow passage 16. Each nozzle flow passage 17 opens externally at its ejection port 18. In each nozzle 12, an ejection port 18 is formed at a projecting end from the head main body 11.
Each nozzle 12 is, for example, a needle nozzle. The outer diameter of each nozzle 12 is not particularly limited; however, it is preferably as small as possible. By reducing the outer diameter of each respective nozzles 12, an electric field concentration tends to take place in the vicinity of the respective ejection ports 18 of the nozzles 12 when a voltage is applied between the electrospinning head 2 and the collection body 5, as described later. The generation of the electric field concentration in the vicinity of the respective ejection ports 18 of the nozzles ensures a high electric field intensity between each nozzle 12 and the collection body 5, even when the voltage applied between the electrospinning head 2 and the collection body 5 is lowered. In an example, the outer diameter of each nozzle 12 is, for example, about 0.3 mm or larger and 1.3 mm or smaller.
The opening size of each ejection port 18 is not particularly limited, as long as it is within a range smaller than the outer diameter of each nozzle 12. Each opening size of the ejection ports 18 is properly set corresponding to the type, etc. of fiber 100 to be deposited on a surface of the collection body 5. In an example, each opening size of the ejection ports 18 is, for example, about 0.1 mm or larger and 1 mm or smaller.
The supply source 3 of the raw material liquid includes a reservoir 31, a supply driver 32, a supply adjuster 33, and a supply pipe 35. The reservoir 31, supply driver 32, supply adjuster 33, and supply pipe 35 respectively have resistance to the raw material liquid. In an example, the reservoir 31 and the supply pipe 35 are respectively formed of an insulating material, such as a fluorine resin.
The reservoir 31 is a tank or the like to store a raw material liquid. In the raw material liquid, a polymer material is dissolved in a solvent. The polymer contained in the raw material liquid and the solvent to dissolve the polymer are properly determined so as to correspond to the type, etc. of the fiber 100 to be deposited on a surface of the collection body 5. The supply pipe 35 connects the reservoir 31 and the head main body 11 of the electrospinning head 2. A flow passage of the raw material liquid is formed inside the supply pipe 35.
An inflow port 22 is formed at one end of the head flow passage 16 of the head main body 11. The supply pipe 35 is connected to the head main body 11 at the inflow port 22, and the head flow passage 16 communicates with the inside of the supply pipe 35 at the inflow port 22. In the present embodiment, the inflow port 22 is formed on one end face of the head main body 11, in the direction along the longitudinal axis C. The other end of the head flow passage 16, i.e., the opposite end of the head flow passage 16 to the inflow port 22 in the head flow passage 16, closes to the outside of the head main body 11. In an example, the other end of the head flow passage 16 is closed by the head main body 11 itself, and in another example, the other end of the head flow passage 16 is closed by a lid member, etc. attached to the head main body 11.
The supply driver 32 is driven to thereby supply the raw material liquid from the reservoir 31 to the head flow passage 16 of the head main body 11 through the supply pipe 35. In an example, the supply driver 32 is a pump. In another example, the supply driver 32 pressure-feeds the raw material liquid from the reservoir 31 to the head flow passage 16 by supplying a gas to the reservoir 31.
The supply adjuster 33 adjusts the rate of flow, pressure, etc. of the raw material liquid supplied to the head flow passage 16. In an example, the supply adjuster 33 is a control valve capable of controlling the rate of flow, pressure, etc. of the raw material liquid. The supply adjuster 33 constrains the ejection of the raw material liquid from the respective ejection ports 18 of the nozzles 12 by adjusting the rate of flow, pressure, etc. of the raw material liquid. The supply adjuster 33 adjusts the rate of flow, pressure, etc. of the raw material liquid to appropriate values based on the viscosity of the raw material liquid, respective sizes of the ejection ports 18, etc. Furthermore, in an example, the supply adjuster 33 is switchable between supplying and not supplying the raw material liquid from the reservoir 31 to the head flow rate 16. In this case, the supply adjuster 33 is, for example, a switch valve.
The supply driver 32 and supply adjuster 33 need not necessarily be provided. In an example, the reservoir 31 is provided on the vertically upper side, with respect to the head main body 11 to supply the raw material liquid from the reservoir 31 to the head flow passage 16 by utilizing gravitational force. In this case, the ejection of the raw material liquid from the respective ejection ports 18 of the nozzles 12 is constrained in a state where no voltage is applied between the electrospinning head 2 and the collection body 5 by adjusting the difference in height of the reservoir 31 with respect to the head main body 11.
The electric power source 4 applies a voltage between the electrospinning head 2 and the collection body 5. In this case, in the electrospinning head 2, a voltage with predetermined polarity is applied to the each nozzle 12 via the head main body 11 and one corresponding connector 13. In an example, a terminal (not shown) electrically connected to each nozzle 12 is provided, and a voltage is applied to each nozzle 12 via the terminal. In a configuration where a terminal(s) is provided, the head main body 11 and the connectors 13 need not be formed of a conductive material. As described above, it suffices that the electric power source 4 is configured to apply a voltage to each nozzle 12.
The nozzles 12 are electrically connected to each other. Therefore, in a state where a voltage is applied to each nozzle 12, the nozzles 12 come to have identical or substantially identical electric potential to one another. The voltage applied to each nozzle 12 may have a positive polarity or negative polarity. In the example shown in FIG. 1, the electric power source 4 is a direct-current electric power source and applies a positive voltage to each nozzle 12.
The collection body 5 is formed of a conductive material. The collection body 5 has resistance to the raw material liquid, and in an example, it is formed of stainless steel. The collection body 5 is disposed on the side where each of the ejection ports 18 opens with respect to the electrospinning head 2. Therefore, the collection body 5 is disposed on the side where the raw material liquid is ejected from the ejection ports 18 with respect to the electrospinning head 2.
In the example of FIG. 1, the collection body 5 is grounded. For this reason, in a state where a positive voltage is applied to each nozzle 12, the voltage to ground of the collection body 5 becomes OV or substantially OV. In another example, the collection body 5 is not grounded. The electric power source 4 applies, to the collection body 5, a voltage with counter-polarity to that of each nozzle 12.
In a state where the raw material liquid is supplied to the electrospinning head 2 by the supply source 3, the raw material liquid is ejected from each ejection port 18 of the nozzles 12 toward the collection body 5 by applying a voltage between each nozzle 12 and the collection body 5 by means of the electric power source 4, as described above. In other words, the raw material liquid is ejected toward the collection body 5 by an electric potential difference between each nozzle 12 and the collection body 5. The raw material liquid is ejected from each ejection port 18 of the nozzles 12 toward the collection body 5, so that fiber 100 is deposited on the surface of the collection body 5, and a film of the fiber 100 is formed by the deposited fiber 100. That is, a film of the fiber 100 is formed by an electrospinning method (which may be referred to as an “electric spinning method” or “charge-induced spinning method”).
The voltage applied between the electrospinning head 2 and the collection body 5, i.e., an electric potential difference between each nozzle 12 and the collection body 5, is adjusted to a suitable size, corresponding to the kind of polymer contained in the raw material liquid and the distance from each nozzle 12 to the collection body 5, etc. In an example, a 10 kV or higher and 100 kV or lower direct current-voltage is applied between each nozzle 12 and the collection body 5. In an example, the direction along the longitudinal axis C of the electrospinning head 2 is identical or substantially identical to the width direction of the collection body 5. The width direction of a formed film of the fiber 100 is identical or substantially identical to the direction along the longitudinal direction C of the electrospinning head 2.
The collection body 5 is formed into a plate or sheet. When the collection body 5 is formed into a sheet, the fiber 100 may be deposited on a collection body 5 wound to the outer circumferential surface of a roll or the like. The collection body 5 may be movable.
In an example, a pair of rotating drums and a driving source to drive the rotating drums are provided. The rotating drums are driven by the driving source, so that the collection body 5 moves between the pair of rotating drums in a similar manner to that of a conveyor belt. In this case, for example, the moving direction (conveying direction) of the collection body 5 crosses (becomes perpendicular or substantially perpendicular to) the width direction of the collection body 5. The movement (conveyance) of the collection body allows a region in which the fiber 100 is deposited on the surface of the collection body 5 to change depending on time. With this configuration, the fiber 100 can be continuously deposited on the collection body 5 depending on time, and a film of the fiber 100 as a deposit of the fiber 100 is efficiently manufactured.
The film of the fiber 100 formed on the surface of the collection body 5 is removed from the collection body 5. The film of the fiber 100 is not limited thereto; however, it is used for an unwoven fabric, a filter, and the like.
In an example, the collection body 5 is not provided. In this case, a substrate formed of a conductive material is used, and a voltage is applied between each nozzle 12 and the substrate, so that the raw material liquid is ejected from each ejection port 18 of the nozzles 12 toward the substrate. A film of the fiber 100 is then formed on a surface of the substrate by depositing the fiber 100 on the surface of the substrate. In this case, the substrate may be grounded, and a voltage with counter-polarity to that of each nozzle 12 may be applied to the substrate by the electric power source 4.
In another example, a substrate is placed on the collection body 5, and a voltage is applied between each nozzle 12 and the collection body 5 as described above. The fiber 100 is deposited on a surface of the substrate placed on the collection body 5 to form a film of the fiber 100 on the surface of the substrate. In this case, even when the substrate has electrically insulating properties, a film of the fiber 100 can be formed on the surface of the substrate.
When the substrate is placed on the collection body 5, the substrate may be movable on the collection body 5. In an example, a rotating drum around which a sheet-like substrate is wound and a rotating drum which winds up the substrate in which a film of the fiber 100 is formed on the surface are provided. Each drum rotates, so that the substrate moves on the collection body 5. At that time, for example, the moving direction (conveying direction) of the substrate crosses (is perpendicular or substantially perpendicular to) the width direction of the substrate. The movement (conveyance) of the substrate allows a region in the surface of the substrate where the fiber 100 is deposited to change depending on time. With this configuration, the fiber 100 can be continuously deposited on the substrate depending on time, and a film of the fiber 100 as a deposit of the fiber 100 is efficiently manufactured.
An example of forming a film of the fiber 100 on a surface of the substrate is not limited thereto and includes the manufacture of a separator integrated electrode for batteries. In this case, one of a negative electrode and a positive electrode in an electrode group is used as a substrate. A film of the fiber 100 formed on a surface of the substrate will be a separator integrated with a negative or positive electrode.
A controller 6 is, for example, a computer, etc. The controller 6 includes a processor or an integrated circuit (control circuit) including a central processing unit (CPU), an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA), etc., and a storage medium, such as a memory. The controller 6 may include only one integrated circuit, etc. or a plurality of integrated circuits, etc. The controller 6 executes a program, etc. stored in the storage medium, etc. to thereby perform processing. The controller 6 controls driving of the supply driver 32, actuation of the supply adjuster 33, output from the electric power source 4, etc.
As shown in FIGS. 2 to 5, the electrospinning head 2 includes a plurality of head units 21A, 21B (two in the present embodiment). The head units 21A, 21B are arranged along the longitudinal axis C. The head units 21A, 21B are coupled to each other. In the present embodiment, the two head units 21A, 21B are coupled, so that the electrospinning head 2 is formed. The other head unit 21B is coupled to the head unit 21A on one side in a direction along the longitudinal axis C. For this reason, in the present embodiment, the head units 21A and 21B are adjacent to each other in the direction along the longitudinal axis C.
Each of the head units 21A and 21B includes a unit main body 23. Each head main body 23 extends with the longitudinal axis C as a central axis. In the electrospinning head 2, a head main body 11 is formed of the unit main bodies 23 of the head units 21A, 21B. The outer circumferential surface of the head main body 11 is formed of the outer circumferential surfaces of the unit main bodies 23 of the head units 21A, 21B. In addition, the head units 21A, 21B are coupled in a state where the unit main bodies 23 of the head units 21A and 21B are coaxial or substantially coaxial with each other.
In each of the head units 21A, 21B, a hollow 25 is formed along the longitudinal axis C inside of the unit main body 23. In each of the head units 21A, 21B, the hollow 25 is formed coaxially or substantially coaxial with the unit main body 23, and the central axis of the hollow 25 is formed coaxially or substantially coaxial with the longitudinal axis C. In the electrospinning head 2, the head units 21A, 21B are coupled in a state where the hollows 25 of the unit main bodies 23 of the head units 21A, 21B communicate with each other. The head flow passage 16 is then formed along the longitudinal axis C by the hollows 25 of the unit main bodies 23 of the head units 21A, 21B.
In each of the head units 21A and 21B, the nozzle 12 described above is arranged on the outer circumferential surface of the unit main body 23. In an example of FIG. 2, etc., two nozzles 12 are provided in the head unit 21A, and two nozzles 12 are provided in the head unit 21B. The number of nozzles 12 provided in each of the head units 21A, 21B is not particularly limited, and it suffices that one or more nozzles 12 are connected to each unit main body 23 of the head units 21A, 21B.
In the example of FIG. 2, etc., an end face of the head main body 11 on one side in the direction along the longitudinal axis C is formed of the unit main body 23 of the head unit 21A, and the other end face of the head main body 11 on the other side in the direction along the longitudinal axis C is formed of the unit main body 23 of the head unit 21B. An inflow port 22 of the head flow passage 16 is formed in the head unit 21A.
A sealing member 20 is provided between the adjacent head units 21A, 21B adjacent in the direction along the longitudinal axis C. Therefore, the sealing member 20 is placed on a coupling face P of the adjacent head units 21A, 21B. The sealing member 20 is, for example, a washer or ring, etc. An example of a material forming the sealing member 20 includes polytetrafluoroethylene (PTFE). The sealing member 20 maintains a space between the unit main bodies 23 of the head units 21A and 21B in a liquid-tight manner at the coupling face P. This configuration prevents the raw material liquid from flowing out from the head flow passage 16 to the outside of the head main body 11.
The coupling face P passes by a position away from each nozzle 12. In the present embodiment, the coupling face P is perpendicular or substantially perpendicular to the longitudinal axis C. A normal line direction (direction shown by arrows N1 and N2) of the coupling face P is identical or substantially identical to the direction along the longitudinal axis C, and is parallel or substantially parallel to the longitudinal axis C.
Here, a coupling structure (coupling) that couples the head units 21A, 21B to each other will be described. In each unit main body 23 of the head units 21A and 21B, one or more holes 26 are formed along the longitudinal axis C. In the present embodiment, three holes 26 are formed in each of the head units 21A, 21B. In each of the head units 21A and 21B, each hole 26 penetrates through the unit main body 23 in the direction along the longitudinal axis C. In each of the head units 21A and 21B, the holes 26 are respectively formed on the inner circumference side with respect to the outer circumferential surface of the unit main body 23 and nozzles 12, and are formed between the hollow 25 and the outer circumferential surface of the unit main body 23 in the radial direction of the unit main body 23.
In each of the head units 21A and 21B, the holes 26 are formed away from one another around the longitudinal axis C. In an example, the holes 26 are arranged at regular or substantially regular intervals around the longitudinal axis C. In addition, each hole 26 of the head unit 21A is arranged at the same or substantially the same angular position with one corresponding hole 26 in the head unit 21B in a direction around the longitudinal axis C.
In the present embodiment, as many holes 27 as there are holes 26 formed in the head unit 21A, i.e., as many as the holes 26 formed in the head unit 21B, are formed in the sealing member 20. Each hole 27 penetrates through the sealing member 20 in the direction along the longitudinal axis C. Each hole 27 is arranged at the same or substantially the same angular position with one corresponding hole 26 in the head unit 21A and one corresponding hole 26 in the head unit 21B around the longitudinal axis C. In the head main body 11, each hole 26 of the head unit 21A communicates with one corresponding hole 26 in the head unit 21B via one corresponding hole 27 in the sealing member 20.
As many bolts 28 as there are holes 26 formed in the head unit 21A, i.e., as many as the holes 26 formed in the head unit 21B, are fixed, as fastening members, to the head main body 11. Each bolt 28 is inserted into one corresponding hole 26 in the head unit 21A, one corresponding hole 27 in the sealing member 20, and one corresponding hole 26 in the head unit 21B. In addition, respective head portions of the bolts 28 abut an end face of the head main body 11 on one side in the direction along the longitudinal axis C. A single corresponding nut 29 is fastened to each bolt 28 via screw-fitting, etc. at an end of the bolt 28 opposite the head portion. Each nut 29 abuts the head main body 11 at the end face opposite to the end face which abuts the head portion of the bolt 28.
The bolts 28 and the nuts 29 are fixed to the head main body 11 as described above, so that the head main body 11 is fastened in the direction along the longitudinal axis C by the bolts 28 and nuts 29. In other words, the head main body 11 is compressed between the head portions of the bolts 28 and the nuts 29 in the direction along the longitudinal axis C. The head units 21A and 21B are coupled to each other through fastening involving use of the bolts 28 and the nuts 29.
In the present embodiment, since the bolts 28 and the nuts 29 are attached to the head main body 11 as described above, the bolts 28 and nuts 20 are provided on the inner circumferential side with respect to the outer circumferential surface of each unit main body 23 of the head units 21A, 21B and the nozzle 12. The bolts 28 and nuts 29 are formed between the head flow passage 16 (hollow 25) and the outer circumferential surface of the head main body 11 according to the radial direction of the head main body 11. Therefore, in the present embodiment, the coupling structure coupling the head units 21A and 21B to each other is provided on the inner circumferential side with respect to the outer circumferential surface and the nozzles 12 in each unit main body 23 of the head units 21A, 21B. That is, the coupling structure (coupling) is not formed on the outer circumferential surfaces of the unit main bodies 23 on which the nozzles 12 are arranged.
The bolts 28 and nuts 29 are formed of a conductive material. In the present embodiment, the head portion of the bolt 28 abuts one end face of the head main body 11 in the direction along the longitudinal axis C as described above. The nut 29 abuts the head main body 11 at the end face opposite to the end face which abuts the head portion of the bolt 28. For this reason, in the present embodiment, the head units 21A and 21B are electrically connected to each other via the bolts 28 and the nuts 29. Also, in each of the head units 21A and 21B, the unit main body 23 is electrically connected to the nozzles 12. Therefore, when a voltage is applied to the electrospinning head 2 by the electric power source 4 as described above, the nozzles 12 in the head unit 21A and the nozzles 12 in the head unit 21B come to have identical or substantially identical electric potential to each other.
In the present embodiment, the plurality of head units 21A and 21B are arranged along the longitudinal axis C, and the head units 21A and 21B are coupled to each other. For this reason, the size of the head main body 11 in the direction along the longitudinal axis C can be increased. In the head main body 11, which is large in size in the direction along the longitudinal axis C, a plurality of nozzles 12 are arranged along the longitudinal axis C. By configuring the head main body 11 as described above, a film of the fiber 100, large in size in the direction along the longitudinal axis C of the head main body 11, is appropriately formed. That is, a film of the fiber 100, large in size in its width direction, is appropriately formed.
In the present embodiment, since the plurality of nozzles 12 are arranged as described above, when the film of the fiber 100 is formed as described above by the ejection of the raw material liquid from the nozzles 12, it is unnecessary to reciprocally move the nozzles 12 in the width direction of the film of the fiber 100, for example. Therefore, it is unnecessary to provide a driving system for moving the nozzles 12 in the electrospinning apparatus 1. Therefore, in the electrospinning apparatus 1, its configuration, control system, etc. will not be complicated.
In addition, in the present embodiment, the head units 21A and 21B are coupled in a state where the hollows 25 of the unit main bodies 23 of the head units 21A and 21B communicate with each other. A head flow passage 16 is then formed along the longitudinal axis C by the hollows 25 of the unit main bodies 23 of the head units 21A and 21B. Since the head flow passage 16 is formed as described above, in the present embodiment, it is unnecessary to form, in a single member, a hole (hollow), large in size in the direction along the longitudinal axis C, in the formation of the head main body 11. Therefore, the manufacturing costs of the head main body 11 and the electrospinning head 2 are suppressed, and their productivity increases.
In the present embodiment, a space between the unit main bodies 23 of the head units 21A and 21B is maintained in a liquid-tight manner by the sealing member 20. The outflow of the raw material liquid from the head flow passage 16 to the outside of the head main body 11 is prevented at a coupling face P by the sealing member 20. For this reason, even with the configuration where the head flow passage 16 is formed by configuring the hollows 25 of the unit main bodies 23 of the head units 21A and 21B to communicate with each other, the outflow of the raw material liquid from the head flow passage 16 is effectively prevented.
In the present embodiment, the head units 21A and 21B are electrically connected to each other via the bolts 28 and the nuts 29. In each of the head units 21A and 21B, the unit main body 23 is electrically connected to the nozzles 12. Therefore, when a voltage is applied from the electric power source 4, each nozzle 12 of the head units 21A and 21B comes to have an identical or substantially identical electric potential to each other by connecting the electric power source 4 to one of the unit main bodies 23 of the head units 21A, 21B. This prevents complication of the configuration of the power feeding system that applies a voltage to the electrospinning head 2.
In the present embodiment, the bolts 28, the nuts 29, etc. are provided on the inner circumferential side with respect to the outer circumferential surface and the nozzles 12 in each unit main body 23 of the head units 21A, 21B. For this reason, even if the coupling structure for coupling the head units 21A and 21B is provided, protruding portions other than the nozzles 12 are not formed in the vicinity of the nozzles 12 on the outer circumferential surface of the head main body 11. Therefore, the influence of the coupling structure on an electric field in the vicinity of the nozzles 12 is suppressed, even if the coupling structure of the head units 21A and 21B is provided.
(Modifications)
In a first modification shown in FIGS. 6 to 9, nozzles 12A, 12B are provided as the nozzles 12 on the outer circumferential surface of the head main body 11. In this modification, the nozzles 12A and 12B are respectively provided in plural numbers. In addition, in this modification, a plurality of nozzles (first nozzles) 12A are arranged at the same or substantially the same angular positions with respect to one another around the longitudinal axis C, and a plurality of nozzles (second nozzles) 12B are arranged at the same or substantially the same angular positions with respect to one another around the longitudinal axis C. Therefore, in this modification, the plurality of nozzles 12A are arranged along the longitudinal axis C to form a nozzle row (first nozzle row) 15A. Also, the plurality of nozzles 12B are arranged along the longitudinal axis C to form a nozzle row (second nozzle row) 15B. Here, FIG. 6 is a perspective diagram of the electrospinning head 2, and FIG. 7 shows a state where the electrospinning head 2 is viewed from a direction crossing (perpendicular or substantially perpendicular to) the longitudinal axis C. FIG. 8 shows a cross-section of the electrospinning head 2 parallel or substantially parallel to the longitudinal axis C, and FIG. 9 shows a cross-section of the electrospinning head 2 perpendicular or substantially perpendicular to the longitudinal axis C.
The nozzles 12B are provided so as to be shifted with respect to the nozzles 12A around the longitudinal axis C. Therefore, the nozzle row 15B is formed so as to be shifted with respect to the nozzle row 15A. In this modification, however, both the nozzles 12A and 12B are arranged on the side where the collection body 5 is positioned with respect to the longitudinal axis C. For example, the nozzles 12A are provided so as to be shifted by about 60° from the nozzles 12B around the longitudinal axis C. In an example of FIG. 6, etc., two sets of each nozzle 12A and 12B are provided in the head unit 21A, and two sets of each nozzle 12A and 12B are provided in the head unit 21B. Therefore, four sets of each nozzle 12A and 12B are provided in the head main body 11. The numbers of the nozzles 12A and 12B provided respectively in the head units 21A and 21B are not particularly limited, and it suffices that one or more nozzles 12A and one or more nozzles 12B are connected to each unit main body 23 of the head units 21A, 21B.
In the electrospinning head 2, a nozzle flow passage 17A is formed in each nozzle 12A, and a nozzle flow passage 17B is formed in each nozzle 12B. Each of the nozzle flow passages 17A and 17B communicates with the head flow passage 16 and extends from the head flow passage 16 toward the outer circumference side of the head main body 11. Each nozzle flow passage 17A opens toward the outside at an ejection port 18A, and each nozzle flow passage 17B opens toward the outside at an ejection port 18B. In each nozzle 12A, the ejection port 18A is formed at a projecting end from the head main body 11. In each nozzle 12B, the ejection port 18B is formed at a projecting end from the head main body 11.
The nozzles 12A and 12B are arranged in a zigzag manner on the outer circumferential surface of the head main body 11. The nozzles 12A and the nozzles 12B are alternately arranged in the direction along the longitudinal axis C. Therefore, one corresponding nozzle (second nozzle) 12B is disposed between adjacent nozzles (first nozzles) in the direction along the longitudinal axis C.
Also in this modification, the sealing member 20 is placed on a coupling face P of the head units 21A, 21B adjacent to each other. The coupling face P passes by a position away from both the nozzles 12A and 12B. In this modification, however, the nozzles 12A and 12B are arranged in a zigzag manner as described above. For this reason, the coupling face P is inclined relative to the longitudinal axis C. The normal line direction of the coupling face P (the direction shown by the arrows N1 and N2) is inclined relative to the longitudinal axis C.
In this modification, a nozzle 12B is disposed between nozzles 12A adjacent to each other in the direction along the longitudinal axis C. Therefore, in the collection body or the substrate, the fiber 100 is deposited by the nozzle 12B, even in a region between the nozzles 12A adjacent to each other in the direction along the longitudinal axis C. This configuration effectively prevents the fiber 100 from being locally deposited on the collection body 5 or the substrate. Therefore, it is possible to effectively prevent a formed film of the fiber 100 from having uneven thicknesses.
The coupling face P is inclined relative to the longitudinal axis C. Therefore, the head units 21A and 21B can be coupled at the coupling face P passing by a position located away from both the nozzles 12A and 12B, even when the nozzles 12A and 12B are arranged in a zigzag manner as described above.
Furthermore, the coupling structure which couples the head units 21A and 21B is not limited to the above-mentioned coupling structure using the bolts (fastening member) 28 and the nuts 29. For example, in a second modification shown in FIGS. 10 and 11, a male screw 41 is formed in the unit main body 23 of the head unit 21A. A female screw 42 is formed in a unit main body 23 of a head unit 21B. In this modification, the male screw 41 is screw-fitted into the female screw 42, so that the head units 21A and 21B are coupled to each other. Therefore, a coupling structure (coupling) which couples the head units 21A and 21B is formed by the male screw 41 and the female screw 42. Here, FIG. 10 shows a state where the electrospinning head is viewed from a direction crossing (perpendicular or substantially perpendicular to) the longitudinal axis C, and the head units 21A and 21B are separated from each other. FIG. 11 shows a cross-section parallel or substantially parallel to the longitudinal axis C.
Also in this modification, the coupling structure formed from the male screw 41 and the female screw 42 is provided on the inner circumference side with respect to the outer circumferential surface and the nozzles 12 of each unit main body 23 of the head units 21A, 21B. The coupling structure is formed between a head flow passage 16 (hollow 25) and the outer circumferential surface of a head main body 11, in the radial direction of the head main body 11. Therefore, also in this modification, the coupling structure which couples the head units 21A and 21B to each other is not formed on the outer circumferential surface of the unit main body 23 on which the nozzles 12 are arranged. For this reason, the influence of the coupling structure on an electric field in the vicinity of the nozzles 12 is suppressed.
Furthermore, also in this modification, the sealing member 20 is placed on the coupling face P of the head units 21A, 21B. In this modification, a sealing member 20 is placed on the outer circumference side of the male screw of the head unit 21A. Also in this modification, the head units 21A and 21B are electrically connected to each other via the male screw 41 and the female screw 42, and the unit main body 23 is electrically connected to the nozzles 12 in each head unit 21A and 21B. By virtue of the configuration described above, the electrospinning head according to this modification exerts similar function and advantageous effects to those in the first embodiment.
In a modification, a male screw is formed in the head unit 21B, and a female screw to be screw-fitted into the male screw is formed in the head unit 21A.
In a third modification shown in FIGS. 12 and 13, a flange 45 is formed on each unit main body 23 of the head units 21A and 21B. In each of the head units 21A and 21, the flange 45 protrudes to the outer circumference side in the outer circumferential surface of the unit main body 23. The flange 45 is, however, provided away from the nozzles 12, around the longitudinal axis C. The flange 45 is preferably provided on the opposite side to a side where the nozzles 12 are positioned, with respect to the longitudinal axis C. In an example, the flange 45 is disposed away from the nozzles 12 by about 180° around the longitudinal axis C. Here, FIG. 12 shows a state where the electrospinning head is viewed from a direction crossing (perpendicular or substantially perpendicular to) the longitudinal axis C. FIG. 13 shows a state where the electrospinning head is viewed from one side (the side where an inflow port 22 is positioned) in a direction along the longitudinal axis C.
In the head unit 21A, a flange 45 is formed at the end of the side where the head unit 21B is positioned in the direction along the longitudinal axis C. In the head unit 21B, the flange 45 is formed at the end of the side where the head unit 21A is positioned in the direction along the longitudinal axis C. In this modification, the flanges 45 of the head units 21A, 21B abut each other. The flanges 45 of the head units 21A, 21B are fastened in the direction along the longitudinal axis C by a bolt 46 and a nut 47. The head units 21A and 21B are coupled to each other by the fastening of the flanges 45 of the head units 21A, 21B through use of the bolt 46 and the nut 47. Therefore, in this modification, the coupling structure (coupling) which couples the head units 21A and 21B is formed by the flanges 45, bolt 46 and nut 47.
In this modification, the coupling structure is provided on the outer circumferential surface of each unit main body 23 of the head units 21A, 21B. However, the coupling structure including the flanges 45 is provided away from the nozzles 12, around the longitudinal axis C. For this reason, in the vicinity of the nozzles 12 on the outer circumferential surface of the head main body 11, protruding portions other than the nozzles 12 are not formed, similarly to the embodiments described above. Therefore, also in this modification, the influence of the coupling structure on an electric field in the vicinity of the nozzles 12 is suppressed.
Furthermore, also in this modification, the sealing member 20 is placed on a coupling face P of the head units 21A, 21B. In this modification, in the coupling face P, the sealing member 20 is placed on the inner circumference side of the flange 45 of the head unit 21A. Furthermore, in this modification, the head units 21A and 21B are electrically connected to each other via the flanges 45, and the unit main bodies 23 in each of the head units 21A and 21B are electrically connected to the nozzles 12. By virtue of the configuration described above, the electrospinning head according to this modification exerts similar function and advantageous effects to those in the first embodiment.
In another modification, the sealing member 20 is formed of a conductive rubber, etc., and has conductivity. In this case, the head units 21A and 21B are electrically connected to each other via the sealing member 20.
In the above-mentioned embodiments, the electrospinning head 2 is formed from two head units 21A and 21B; however, the configuration thereof is not limited to that disclosed above. In a fourth modification shown in FIG. 14, an electrospinning head 2 is formed from three head units 21A to 21C. Also in this modification, the head units 21A to 21C are arranged along the longitudinal axis C and coupled to one another. Also, hollows 25 of unit main bodies 23 of the head units 21A to 21C communicate with one another, and a head flow passage 16 is formed along the longitudinal axis C by the hollows 25 of the unit main bodies 23 of the head units 21A to 21C.
In this modification, the head units 21A and 21B are coupled to each other in the same manner as in any one of the above-mentioned embodiments. The head units 21B and 21C are coupled to each other in the same manner as in any one of the above-mentioned embodiments. When a voltage is applied to the electrospinning head 2 by an electric power source 4, the nozzles 12 in the head units 21A to 21C come to have an identical or substantially identical electric potential to one another. In this modification, a sealing member 20 is placed on a coupling face of the head units 21A and 21B which are adjacent to each other, and the sealing member 20 is placed on a coupling face of the head units 21B and 21C which are adjacent to each other. Also in this modification, similar function and advantageous effects to those of the above-mentioned embodiments are exerted.
Furthermore, in a modification, an electrospinning head 2 is formed by coupling four or more head units 21 to one another. Also in this case, the head units 21 are coupled to one another to form a head flow passage 16, in the same manner as in any one of the above-mentioned embodiments.
According to at least one embodiment or example of those described above, another head unit can be coupled to the head unit on at least one side in the direction along the longitudinal axis C by the coupling structure. The coupling structure couples a unit main body of said another head unit to the unit main body of the head unit, in a state where the hollow of the unit main body of the head unit communicates with the hollow of the unit main body of said another head unit. With this configuration, it is possible to provide a head unit capable of suppressing the complexity of its configuration and its control system in addition to an increase in manufacturing costs and a reduction in productivity of the electrospinning head, and which can appropriately form a film of fiber large in size in the width direction.
In addition, according to at least one embodiment or example of those described above, the plurality of head units are coupled to one another by the coupling structure. The coupling structure couples a plurality of head units in a state where the hollows of their unit main bodies communicate with one another. Thereby, it is possible to provide an electrospinning head which suppresses the complexity of its configuration and its control system in addition to an increase in manufacturing costs and a reduction in productivity of the electrospinning head, and which can appropriately form a film of fiber large in size in the width direction.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

Claims

What is claimed is:

1. A head unit comprising:

a unit main body in which a hollow configured to store a raw material liquid is formed along a longitudinal axis of the head unit; and

a nozzle formed of a conductive material and provided on an outer circumferential surface of the unit main body, the nozzle being configured to eject the raw material liquid supplied through the hollow of the unit main body, and

the head unit further comprising:

a coupling structure capable of coupling another head unit to the head unit on at least one side in a direction along the longitudinal axis of the head unit,

wherein the coupling structure couples a unit main body of said another head unit to the unit main body of the head unit, in a state where the hollow of the unit main body of the head unit communicates with a hollow of the unit main body of said another head unit, so that a head flow passage is formed along the longitudinal axis by the hollow of the head unit and the hollow of said another head unit which communicates with the hollow of the head unit.

2. The head unit according to claim 1, comprising:

plural of the nozzle,

wherein the plural of the nozzle includes a first nozzle and a second nozzle provided so as to be shifted with respect to the first nozzle around the longitudinal axis of the head unit.

3. An electrospinning head comprising:

a plurality of head units arranged along a longitudinal axis of the electrospinning head; and

a coupling structure that couples the plurality of head units to one another;

each of the plurality of head units including:

a unit main body in which a hollow configured to store a raw material liquid is formed along the longitudinal axis; and

a nozzle formed of a conductive material and provided on an outer circumferential surface of the unit main body, the nozzle being configured to eject the raw material liquid supplied through the hollow of the unit main body,

wherein the coupling structure couples the plurality of head units in a state where the hollows of the unit main bodies communicate with one another, so that a head flow passage is formed along the longitudinal axis by the hollows communicating with one another.

4. The electrospinning head according to claim 3, wherein the nozzles in the plurality of head units are electrically connected to one another and come to have an identical electric potential to one another by application of a voltage.

5. The electrospinning head according to claim 3, wherein the coupling structure is provided on an inner circumference side with respect to the outer circumferential surface of each unit main body and each nozzle of in the plurality of head units.

6. The electrospinning head according to claim 5, wherein in each of the unit main bodies of the plurality of head units, a hole is formed along the longitudinal axis, on the inner circumference side with respect to the outer circumferential surface,

the coupling structure includes a fastening member to be inserted into the hole, and

the plurality of head units are coupled to one another by fastening of the fastening member.

7. The electrospinning head according to claim 3, wherein the coupling structure is provided away from the respective nozzles of the plurality of head units around the longitudinal axis.

8. The electrospinning head according to claim 3, further comprising:

a sealing member provided between the head units adjacent to each other in a direction along the longitudinal axis, the sealing member being configured to maintain a space between the head units adjacent to each other in a liquid-tight manner so as to prevent the raw material liquid from flowing out of the head flow passage at a coupling face of the head units adjacent to each other.

9. The electrospinning head according to claim 3, wherein each of the plurality of head units includes plural of the nozzle,

in each of the plurality of head units, the plural of the nozzle include a first nozzle and a second nozzle provided so as to be shifted with respect to the first nozzle around the longitudinal axis,

the first nozzles of the plurality of head units form a first nozzle row in which the first nozzles are arranged along the longitudinal axis, and

the second nozzles of the plurality of head units form a second nozzle row in which the second nozzles are arranged along the longitudinal axis, at a position shifted with respect to the first nozzle row around the longitudinal axis.

10. The electrospinning head according to claim 9, wherein the first nozzles in the first nozzle row and the second nozzles in the second nozzle row are arranged in a zigzag manner,

the first nozzles and the second nozzles are alternately arranged in a direction along the longitudinal axis, and

a coupling face of the head units adjacent to each other in the direction along the longitudinal axis and a normal line direction of the coupling face are respectively inclined relative to the longitudinal axis.

11. An electrospinning apparatus comprising:

the electrospinning head according to claim 3;

a supply source configured to supply the raw material liquid to the head flow passage of the electrospinning head; and

an electric power source configured to apply a voltage to the electrospinning head.