SPINNING HEAD AND SPINNING APPARATUS

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2022-024024, filed Feb. 18, 2022; the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate to a spinning head and a spinning apparatus.

BACKGROUND

An spinning apparatus that accumulates fiber on the surface of a substrate with an electrospinning method (sometimes called “electric charge induction spinning method”) to form a fiber film is known. In such a spinning apparatus, a spinning head is provided, and the spinning head includes a head main body and a nozzle projecting from the outer peripheral surface of the head main body toward the outer peripheral side. A storage cavity capable of storing a material liquid is formed in the inside of the head main body, and an ejection port capable of ejecting a material liquid is formed in the nozzle at the projection end from the head main body. In the spinning head, a flow path for a material liquid that communicates with the storage cavity is formed through the inside of the nozzle, up to the ejection port.

As an example of the above-described spinning apparatus, there is an apparatus in which a material liquid is ejected from a nozzle of an spinning head against an area in which a substrate, etc. as a transfer target is transferred in a transfer path in a vertical direction. As a spinning head used in such a spinning apparatus, there is a spinning head having a flow path tilted with respect to a horizontal plane, with the ejection port being located upward in the vertical direction relative to the part connecting to the storage cavity. In such n spinning head having a flow path tilted with respect to a horizontal plane, with the ejection port (the projection end of the nozzle) being located upward in the vertical direction relative to the part connecting to the storage cavity, it is demanded to appropriately prevent residual air in the storage cavity in the inside of the head main body. Furthermore, there is a demand for a spinning head capable of appropriately controlling an influence of residual air on the ejection of a material liquid and providing stable spinning by preventing air from remaining in the storage cavity of the head main body.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 2 is a schematic diagram showing an example of a configuration for ejecting a material liquid from one spinning head in the spinning apparatus according to the first embodiment.

FIG. 3 is a cross-sectional view schematically showing the spinning head in FIG. 2 in a cross section perpendicular to, or approximately perpendicular to, the axial direction of a head main body.

FIG. 4 is a cross-sectional, enlarged view schematically showing one of the nozzles and its vicinity in the cross section shown in FIG. 3.

FIG. 5 is a cross-sectional view showing one nozzle and the vicinity thereof in a spinning head according to a first modification, in a cross section perpendicular to, or approximately perpendicular to, the axial direction of the head main body.

FIG. 6 is a cross-sectional view schematically showing a spinning head according to a second modification in a cross section perpendicular to, or substantially perpendicular to, an axial direction of the head main body.

FIG. 7 is a cross-sectional view schematically showing a spinning head according to a third modification in a cross section perpendicular to, or substantially perpendicular to, an axial direction of the head main body.

DETAILED DESCRIPTION

According to an embodiment, a spinning head configured to eject a material liquid against an area in which a transfer target is transferred in a vertical direction in a transfer path is provided. The spinning head includes a head main body and a nozzle, and a storage cavity capable of storing a material liquid is formed inside the head main body. The nozzle projects from the outer peripheral surface of the head main body, and an ejection port capable of ejecting a material liquid is formed at the projection end from the head main body. A flow path that communicates with the storage cavity extends through the inside of the nozzle, up to the ejection port. The ejection port is located on the upper side of the vertical direction with respect to the connecting part to the storage cavity, and at least a part of the flow path is tilted with respect to a horizontal plane. The upper end of the connecting part of the flow path to the storage cavity is located either at the same height as the upper end of the storage cavity or on the upper side of the vertical direction with respect to the upper end of the storage cavity.

Hereinafter, the embodiments will be described with reference to the accompanying drawings.

First Embodiment

FIG. 1 shows an example of a spinning apparatus 1 according to the first embodiment. As shown in FIG. 1, the spinning apparatus 1 includes a plurality of spinning heads 2, a transfer path 3, and a control unit 4. In the spinning apparatus 1 and the transfer path 3, a vertical direction (the direction indicated by arrows Z1 and Z2), a transverse direction (the direction indicated by arrows Y1 and Y2) intersecting (orthogonal or approximately orthogonal to) the vertical direction, a depth direction (the direction orthogonal or approximately orthogonal to the sheet of FIG. 1) intersecting (orthogonal or approximately orthogonal to) the vertical direction and the transverse direction are defined. Herein, the vertical direction is a direction perpendicular to a horizontal plane. Each of the transverse direction and the depth direction are parallel to or approximately parallel to the horizontal plane. The transfer path 3 has areas E1 and E2 in which a transfer target is transferred in the vertical direction, and in the example shown in FIG. 1, a transfer target is transferred in the vertical direction in each of the two areas E1 and E2. In the transfer path 3, a substrate 8 is transferred as a transfer target.

In the example shown in FIG. 1, a plurality of spinning heads 2A, spinning heads 2B, spinning heads 2C, and spinning heads 2D are provided as a plurality of spinning heads 2. Each spinning head 2A ejects a material liquid from one side of the transverse direction against a transfer target transferred in the vertical direction in the area E1, and each spinning head 2B ejects a material liquid from a side opposite to the spinning heads 2A in the transverse direction toward a transfer target transferred in the vertical direction in the area E1. The plurality of the spinning heads 2A are arranged along the vertical direction, and the plurality of the spinning heads 2B are arranged along the vertical direction. Each spinning head 2C ejects a material liquid from one side of the transverse direction toward a transfer target transferred in the vertical direction in the area E2, and each spinning head 2D ejects a material liquid from a side opposite to the spinning heads 2C in the transverse direction toward a transfer target transferred in the vertical direction in the area E2. The plurality of the spinning heads 2C are arranged along the vertical direction, and the plurality of the spinning heads 2D are arranged along the vertical direction.

FIG. 2 shows an example of a configuration in which a material liquid is ejected from one of spinning heads 2. FIG. 2 shows a configuration in which a material liquid is ejected from one of the spinning heads 2; a material liquid is ejected from other spinning heads 2 in a manner similar to the spinning head 2 shown in FIG. 2. FIG. 2 shows the spinning head 2 viewed from one side of the transverse direction and from the side in which a material liquid is ejected. In FIG. 2, the direction indicated by arrows X1 and X2 are the depth direction of the spinning apparatus 1.

As shown in FIG. 2, etc., the spinning apparatus 1 includes a material liquid supply unit 5 and an electric power supply 6. The material liquid supply unit 5 constitutes a supply source of a material liquid and a supply path for a material liquid from the supply source to each spinning head 2. In one example, a material liquid stored in a tank, etc. is supplied to each spinning head 2 by driving a driving member such as a pump, etc. in the supply unit 5. The supply unit 5 may be provided with either a control valve capable of controlling a flow amount and a pressure, etc. of a material liquid supplied to each spinning head 2 or a switch valve capable of switching between on and off for supplying a material liquid to each spinning head 2.

A material liquid is a solution of a high polymer material in a solvent. A high polymer included in the material liquid, and a solvent in which the high polymer is dissolved are determined as appropriate in accordance with the type, etc. of fiber to be accumulated on the surface of a transfer-targeted substrate 8. A high polymer material is not limited to a specific type, and any type can be used as appropriate according to material properties of fiber to be formed. The examples of the high polymer material are: polypropylene, polyethylene, polystyrene, polyethylene terephthalate, polyvinyl chloride, polycarbonate, nylon, aramid, polyamide-imide, and polyimide etc. Any solvent used for a material liquid is used as long as a high polymer material can dissolve into the solvent. The solvent can be changed as appropriate in accordance with a high-polymer material to dissolve. As the solvent, for example, water, methanol, ethanol, isopropyl alcohol, acetone, benzene, toluene, N-methyl-2-pyrrolidone (NMP), and dimethylacetamide (DMAc), etc. can be used.

Each of the spinning heads 2 includes a head main body 11 and a plurality of nozzles 12. The head main body 11 of each spinning head 2 has a longitudinal axis C as a center axis, and in each spinning head 2, the axial direction of the head main body 11 along the longitudinal axis C is defined. Each spinning head 2 is arranged in such a manner that the axial direction of the head main body 11 coincides with, or approximately coincides with, the depth direction of the spinning apparatus 1. Thus, the longitudinal axis C of the head main body 11 of each spinning head 2 is along the depth direction of the spinning apparatus 1. In each spinning head 2, each of the nozzles 12 projects from the outer peripheral surface of the head main body 11 toward the outer peripheral side. In the example of FIG. 1, in each spinning head 2, each of the nozzles 12 projects from the outer peripheral surface of the head main body 11 toward one side of the transverse direction of the spinning apparatus 1. In each spinning head 2, the axial direction of the head main body 11 intersects with (is perpendicular to or approximately perpendicular to) the vertical direction and the projecting direction of each nozzle 12.

The electric power supply 6 applies a voltage of a predetermined polarity to each spinning head 2. At this time, the polarity is the same for the plurality of spinning heads 2. In each spinning head 2, a voltage is applied by the electric power supply 6 as described above, and a material liquid is supplied from the supply unit 5; as a result, the material liquid is electrified in the same polarity as the voltage applied to the head. The polarity of the voltage applied to the spinning heads 2 from the electric power supply 6 may be positive or negative. In other words, in each spinning head 2, a material liquid may be electrified in a positive polarity or a negative polarity. In the example shown in FIG. 2, etc., in each spinning head 2, the head main body 11 and the plurality of nozzles 12 are made of an electrically conductive material, and a voltage of a predetermined polarity is applied to the head main body 11 and the nozzles 12. In each spinning head 2, the supplied material liquid is electrified in the same polarity as the head main body 11 and the nozzles 12. In the example shown in FIG. 2, the electric power supply 6 is a direct current power source, and a material liquid is electrified in a positive polarity in each spinning head 2.

In another example, only the nozzles 12 are made of an electrically conductive material and the head main body 11 is made of a non-electrically conductive material in each spinning head 2. In each spinning head 2, a voltage of a predetermined polarity is applied to the nozzles 12, and the supplied material liquid is electrified in the same polarity as the nozzles 12. In another example, an electrically conductive part is provided in either a supply source of a material liquid to each spinning head 2 or a supply path for a material liquid between the supply source and each spinning head 2, and a voltage of a predetermined polarity is applied to the electrically conductive part by the electric power supply 6, etc. A material liquid is electrified in the same polarity as the electrically conductive part to which a voltage has been applied. In this case, the material liquid electrified in a predetermined polarity is supplied to each spinning head 2.

In the example of FIG. 2, etc., the substrate 8 transferred on the transfer path 3 is made of an electrically conductive material. The substrate 8 transferred on the transfer path 3 is grounded. Instead of grounding the substrate 8, a voltage of a polarity opposite to that of each spinning head 2 may be applied to the substrate 8 by the electric power supply 6 or an electric power supply other than the electric power supply 6. In the present embodiment, as described above, a material liquid supplied to each spinning head 2 is electrified in a predetermined polarity through the application of a voltage by the electric power supply 6. For this reason, an electric potential difference occurs between the material liquid supplied to each spinning head 2 and the substrate 8, and the electric potential difference causes the nozzles 12 of each spinning head 2 to eject the material liquid against the substrate 8.

As described above, in the example shown in FIG. 2, etc., a material liquid is ejected against the substrate 8 from each spinning head 2 by an electrospinning method (sometimes called “electric charge induction spinning method”), and a fibrous film, etc. is formed on the surface of the substrate 8. The amplitude of the voltage applied to the spinning heads 2, etc. by the electric power supply 6 is set as appropriate, in accordance with a type of a solvent and a solute of a material liquid, a boiling point and steam pressure curve of a solvent of the material liquid, a concentration and temperature of the material liquid, a shape of the nozzles 12, a distance between the substrate 8 and the nozzle 12, and the like. The ejection speed of the material liquid from each nozzle 12 of the spinning head 2 corresponds to a concentration, a viscosity, and a temperature of the material liquid, a voltage applied to the spinning head 2, and a shape of the nozzle 12, and the like.

In the example of FIG. 1, a material liquid is ejected on both surfaces of the substrate 8; in another example, on the other hand, a material liquid may be ejected on a single surface of the substrate 8 slated to be transferred. In this case, a fibrous film, etc. is formed only on one surface of the substrate 8. In another example, a collection body may be transferred as a transfer target on the transfer path 3, instead of the substrate 8. In this case, a material liquid is ejected from each spinning head 2 toward an area in which a collection body is transferred on the transfer path 3 along the vertical direction. Then, a fibrous film, etc. is formed on the collection body. The ejection of the material liquid from each spinning head 2 may be realized by a method other than the electrospinning method. In one example, a material liquid is ejected from each spinning head 2 by a solution blow method. Also, in this case, each spinning head 2 ejects a material liquid in which a high polymer material is dissolved in a solvent against an area in which a transfer target, such as the substrate 8, etc. is transferred along the vertical direction.

The control unit 4 is a computer, for example. The control unit 4 includes a processor or an integrated circuit (control circuit) including a CPU (central processing unit), an ASIC (application specific integrated circuit), or an FPGA (field programmable gate array), and a storage medium (non-transitory storage medium), such as a memory. The control unit 4 may include only one integrated circuit, etc., or a plurality of integrated circuits, etc. The control unit 4 performs processing by executing a program, etc. stored on the storage medium, etc. The control unit 4 controls the supply of a material liquid to each spinning head 2, transferring of a transfer target, such as the substrate 8, etc., and application of a voltage from the electric power supply 6.

In the following, the structure, etc. of the spinning head 2 is described. FIG. 3 shows the spinning head 2 shown in FIG. 2 in a cross section perpendicular to, or approximately perpendicular to, the axial direction of the head main body 11 (the depth direction of the spinning apparatus 1). The structure of one spinning head 2 described hereinafter represents the structure of the other spinning heads 2.

As shown in FIGS. 2 and 3, the spinning head 2 has a head main body 11 and a plurality of nozzles 12, as described earlier. In the spinning head 2 of the example illustrated in FIGS. 2 and 3, etc., a plurality of nozzles 12A and 12B are provided as a plurality of nozzles 12. The plurality of nozzles 12A are arranged at the same or approximately the same angular position with respect to each other around the longitudinal axis C of the head main body 11 (the peripheral direction of the head main body 11); the plurality of nozzles 12B are arranged at the same or approximately the same angular position with respect to each other around the longitudinal axis C of the head main body 11. For this reason, in the example illustrated in FIGS. 2 and 3, etc., the plurality of nozzles 12A are arranged along the axial direction of the head main body 11 to form a nozzle row. The plurality of nozzles 12B are also arranged along the axial direction of the head main body 11 to form a nozzle row differing from that of the nozzles 12A.

The plurality of nozzles 12B are arranged in a manner such that they are deviated from the nozzles 12A in the direction around the longitudinal axis C. In the example illustrated in FIGS. 2 and 3, etc., the deviation of the nozzles 12B with respect to the nozzles 12A in the direction around the longitudinal axis C is smaller than 120 degrees. In the spinning head 2, the nozzles 12B project from the outer peripheral surface of the head main body 11 toward the side toward which the nozzles 12A project, in the transverse direction of the spinning apparatus 1. In the example illustrated in FIGS. 2 and 3, the nozzles 12A and 12B are arranged in a zig-zag manner on the outer peripheral surface of the head main body 11. Furthermore, the nozzles 12A and 12B are alternately arranged in the axial direction of the head main body 11. For this reason, a corresponding one of the nozzles 12B is arranged between two adjacent nozzles 12A according to the axial direction of the head main body 11 (the direction along the longitudinal axis C).

In the spinning head 2, a storage cavity 13 for storing the above-described material liquid is formed in the inside of the head main body 11. In the head main body 11, a storage cavity 13 is formed along the axial direction, and the space surrounded by the cavity peripheral surface 15 is defined as the storage cavity 13. In the example illustrated in FIG. 3, etc., the center axis of the storage cavity 13 is coaxial or substantially coaxial with the longitudinal axis (center axis) C of the head main body 11. In the example of FIG. 3, the cavity peripheral surface 15 of the storage cavity 13 is constituted by the head main body 11 across the entire periphery in the peripheral direction of the storage cavity 13. In the spinning head 2, a material liquid supplied from the supply unit 5 flows into the storage cavity 13.

In each nozzle 12, an ejection port 16 is formed at the projection end from the head main body 11. In the spinning head 2, flow paths 17 are provided in the same number as the number of the nozzles 12, and a flow path 17 is provided in each nozzle 12. In the spinning head 2, each flow path 17 is connected to the storage cavity 13. Each flow path 17 extends from the connecting part 18 to the storage cavity 13 through the inside of a corresponding one of the nozzles 12, up to a corresponding one of the ejection ports 16.

The elements relating to the nozzles 12A are referenced by numerals followed by A, such as “ejection port 16A” and “flow path 17A”. The elements relating to the nozzles 12B are referenced by numerals followed by B, such as “ejection port 16B” and “flow path 17B”. In the example of FIGS. 2 and 3, in each flow path 17B, an ejection port 16B is located at the lower side of the vertical direction (the arrow Z2 side) with respect to the connecting part 18B to the storage cavity 13. Furthermore, each flow path 17B is tilted with respect to a virtual horizontal plane H; for example, it is tilted with respect to the virtual horizontal plane H in such a manner that it extends downward in the vertical direction as it is closer to the ejection port 16B. Thus, each flow path 17B extends downward in the vertical direction as it is closer to the projection end of a corresponding one of the nozzle 12B in the transverse direction.

In each flow path 17A, an ejection port 16A is located at the upper side of the vertical direction (the arrow Z1 side) with respect to the connecting part 18A to the storage cavity 13. At least a part of each flow path 17A is tilted with respect to the virtual horizontal plane H; for example, the flow path 17A is tilted with respect to the horizontal plane H in such a manner that the ejection port 16A extends upward in the vertical direction as it is closer to the ejection port 16A. Thus, each flow path 17A extends upward in the vertical direction as it is closer to the projection end of a corresponding one of the nozzles 12A in the transverse direction. FIG. 3 shows a cross section that passes one of the flow paths 17A. FIG. 3 shows an example where the entirety of each flow path 17A is tilted with respect to the horizontal plane H; on the other hand, as described above, each flow path 17A is arranged so as to have at least a part tilted with respect to the horizontal plane H.

Herein, a flow path axis PA is defined as the center axis of each flow path 17A, and a flow path axis PB is defined as the center axis of each flow path 17B. The flow path axis PA of each flow path 17A is coaxial with, or substantially coaxial with, the center axis of the corresponding one of the nozzles 12A, and the flow path PB of each flow path 17B is coaxial with, or substantially coaxial with, the center axis of the corresponding one of the nozzles 12B. In the example shown in FIGS. 2 and 3, an acute angle θA made by the flow path axis PA of each flow path 17A with respect to the horizontal plane H is equal to or greater than 15 degrees and equal to or less than 60 degrees. An acute angle θB made by the flow path axis PB of each flow path 17B with respect to the horizontal plane H is equal to or greater than 15 degrees and equal to or less than 60 degrees. For this reason, in the example shown in FIGS. 2 and 3, etc., the deviation of the nozzles 12B with respect to the nozzles 12A in the direction around the longitudinal axis C is in an angle range of 30 to 120 degrees.

In the spinning head 2, the space surrounded by a corresponding one of flow path peripheral surfaces 21 is defined as each flow path 17A. In the example of FIG. 3, in each flow path 17A the flow path peripheral surface 21 is constituted by a corresponding one of the nozzles 12A across the entirety of, or approximately the entirety of, the area spanning from the connecting part 18A to the storage cavity 13 to the ejection port 16A. In each flow path 17A, a part of the flow path peripheral surface 21 may be constituted by the head main body 11. In this case, each flow path peripheral surface 21 of the flow path 17A is constituted by a corresponding nozzle 12A and the head main body 11.

FIG. 4 is an enlarged view of one of the nozzles 12A and its vicinity in the cross section shown in FIG. 3. As shown in FIGS. 3 and 4, etc., the cavity peripheral surface 15 of the storage cavity 13 includes a cavity upper surface 22 adjacent to the storage cavity 13 in the upper side of the vertical direction. Each flow path peripheral surface 21 includes a flow path upper surface 23 adjacent to a corresponding flow path 17A from the upper side of the vertical direction. In the example shown in FIGS. 3 and 4, the cavity upper surface 22 is constituted by the head main body 11, and each flow path upper surface 23 is constituted by a corresponding one of the nozzles 12A. In each flow path 17A, the flow path axis PA extends across the entirety from the connecting part 18A to the storage cavity 13 to the ejection port 16A, through the lower side of the vertical direction relative to the flow path upper surface 23.

In each flow path 17A, the upper end U1 of the connecting part 18A to the storage cavity 13 is formed by the flow path upper surface 23. In each flow path 17A, the lower end of the flow path upper surface 23 is defined as the upper end U1 of the connecting part 18A. The upper end U2 of the storage cavity 13 is constituted by the cavity upper surface 22. In the present embodiment, the upper end U1 of the connecting part 18A of each flow path 17A is located either at the same height as the upper end U2 of the storage cavity 13 or on the upper side of the vertical direction with respect to the upper end U2 of the storage cavity 13. For this reason, if a virtual horizontal plane Tα passing the upper end U2 of the storage cavity 13 is defined, the upper end U1 of the connecting part 18A of each flow path 17A is located either on the horizontal plane Tα or on the upper side of the vertical direction relative to the horizontal plane Tα. Thus, in the inside of the head main body 11, there is no space constituted by the storage cavity 13 in the area of the upper side of the vertical direction with respect to the upper end U1 of the connecting part 18A of each flow path 17A.

In another example, the cross-sectional shape of the storage cavity 13 in the cross section perpendicular to the axial direction of the head main body 11 is uniform or approximately uniform in the range in which the connecting part 18A of each flow path 17A is formed according to the axial direction of the head main body 11. In this case, the cross-sectional shape of the spinning head 2 in the cross section perpendicular to the axial direction of the head main body 11 is uniform or approximately uniform in the cross-sectional shape shown in FIG. 3 in this range. In the present embodiment, the upper end U1 of the connecting part 18A of each flow path 17A is in the above-described positional relationship with respect to the upper end U2 of the storage cavity 13; therefore, the flow path upper surface 23 of each flow path 17A is located on the upper side of the vertical direction compared to any parts in the cavity upper surface 22.

In the example of FIGS. 3 and 4, etc., in each flow path 17A, the cross-sectional area of the flow path in the cross section perpendicular to the flow path axis PA is uniform, or approximately uniform, from the connecting part 18A to the ejection port 16A. Thus, in each flow path 17A, the cross-sectional area of the flow path does not, or almost does not, change in the area between the connecting part 18A and the ejection port 16A.

In the example of FIGS. 3 and 4, etc., in the flow path upper surface 23 of each flow path 17A, the entirety between the connecting part 18A and the ejection port 16A is tilted with respect to the horizontal plane in such a manner that it extends upward in the vertical direction as it is closer to the ejection port 16A. In other words, the flow path upper surface 23 of each flow path 17A is constituted only by the tilted part that is tilted with respect to the horizontal plane in such a manner that it extends upward in the vertical direction as it is closer to the ejection port 16A. Since the flow path upper surface 23 of each flow path 17A is formed in the above-described manner, in each flow path 17A, the flow path upper surface 23 extends in such a manner that it extends upward in the vertical direction as it is closer to the ejection port 16A (the projection end of the nozzle 12A) in the transverse direction. Furthermore, in the flow path upper surface 23 of each flow path 17A, there is no part extending toward the lower side of the vertical direction as being closer to the ejection port 16A.

In the present embodiment, a material liquid is ejected from each of the spinning heads 2 toward an area in which the substrate 8, etc. is transferred on the transfer path 3 along the vertical direction. For this reason, it is possible to form a fibrous film, etc. on both sides of a substrate 8, etc., with an easy structure. Since a material liquid is ejected against an area in which a substrate 8 is transferred along the vertical direction, the dimensions of the spinning apparatus 1 according to a direction along a horizontal plane, such as the transverse direction, do not increase even when the area in the transfer path 3 against which a material liquid is ejected from the spinning head 2 is increased.

Furthermore, in the present embodiment, in each spinning head 2, each flow path 17A extends through the corresponding one of the nozzles 12A, and each flow path 17A is tilted with respect to a horizontal plane (e.g., H), with the ejection port 16A being located at the upper side of the vertical direction with respect to the connecting part 18A to the storage cavity 13. In each spinning head 2, the upper end U1 of the connecting part 18A to the storage cavity 13 of each flow path 17A is located either at the same height as the upper end U2 of the storage cavity 13 or on the upper side of the vertical direction with respect to the upper end U2 of the storage cavity 13. For this reason, in each spinning head 2, in the inside of the head main body 11, there is no space constituted by the storage cavity 13 in the area of the upper side of the vertical direction with respect to the upper end U1 of the connecting part 18A of each flow path 17A. In each spinning head 2, it is thus possible to appropriately prevent the air that flows into the storage cavity 13 together with a material liquid, etc. from remaining in the storage cavity 13.

As described above, in the present embodiment, in the spinning head 2 having a flow path 17A tilted with respect to a horizontal plane, with the ejection port 16A (the projection end of the nozzle 12A) being located upward in the vertical direction relative to the connecting part 18A to the storage cavity 13, it is possible to appropriately prevent residual air in the storage cavity 13 in the inside of the head main body 11. In each spinning head 2, the prevention of the residual air in the storage cavity 13 leads to appropriate prevention of an influence of air that has remained in the ejection of a material liquid. For example, by preventing residual air in the storage cavity 13, a time from when an ejection of a material liquid starts until an ejection pressure of the material liquid becomes stable is shortened. As residual air in the storage cavity 13 can be prevented, occurrence of bubbles, etc. in a material liquid to be ejected can be effectively prevented.

In the present embodiment, the flow path upper surface 23 of each flow path 17A is constituted only by a tilted part that is tilted with respect to the horizontal plane in such a manner that it extends upward in the vertical direction as it is closer to the ejection port 16A. For this reason, in the flow path upper surface 23 of each flow path 17A, there is no part extending toward the lower side of the vertical direction as being closer to the ejection port 16A. Therefore, in the present embodiment, residual air in each flow path 17A can be appropriately prevented, as well as residual air in the storage cavity 13. Since residual air in the flow path 17A is prevented, a material liquid can be ejected from the ejection port 16A in each flow path 17A in a more stable manner.

In one example, the cross-sectional shape of the storage cavity 13 in a cross section perpendicular to the axial direction of the head main body 11 is uniform, or approximately uniform, in the range where the connecting part 18A of each flow path 17A is formed in the axial direction of the head main body 11. Thus, a configuration that causes the upper end U1 of the connecting part 18A of each flow path 17A to be located either at the same height as the upper end U2 of the storage cavity 13 or on the upper side of the vertical direction with respect to the upper end U2 of the storage cavity 13 can be easily realized.

In the present embodiment, an acute angle θA made by the flow path axis PA of each flow path 17A with respect to the horizontal plane H, and an acute angle θB made by the flow path axis PB of each flow path 17B with respect to the horizontal plane H, are both 15 degrees or larger. For this reason, with a configuration of ejecting a material liquid from each ejection port 16 by an electrospinning method, it is possible to effectively prevent an interference of an electric field between the nozzles 12A and 12B, with a voltage being applied to each of the nozzles 12. It is thus possible to effectively prevent the decline of an electric field intensity in each ejection port 16 (a projection end of each nozzle 12) and its vicinity.

In the present embodiment, each of the above-mentioned acute angles θA and θB is 60 degrees or smaller. For this reason, in the configuration in which a plurality of spinning heads 2 are aligned in the vertical direction as shown in FIG. 1, etc., it is possible to prevent interference between material liquids ejected from the spinning heads 2 vertically adjacent to each other, without increasing an interval between the adjacent spinning heads 2. Since the intervals between the adjacent spinning heads 2 in the vertical direction do not increase, the dimension of the spinning apparatus 1 in the vertical direction does not increase in the spinning apparatus 1 in which a plurality of spinning heads 2 are aligned along the vertical direction as shown in FIG. 1.

Modifications

In the first modification shown in FIG. 5, in each flow path 17A of the spinning head 2, a flow path cross-sectional area varies within the area spanning from the connecting part 18A to the ejection port 16A. In the present modification, the flow path extending parts 25 and 26 and the flow path cross-section changing part 27 are formed in each flow path 17A. In the present modification, in each flow path 17A, a part of the flow path peripheral surface 21 may be constituted by the head main body 11, and a part of the flow path upper surface 23 is constituted by the head main body 11.

In each flow path 17A, the flow path extending part (first flow path extending part) 26 is connected to the storage cavity 13, and the flow path extending part 26 forms the connecting part 18A to the storage cavity 13. In each flow path 17A, the flow path extending part (second flow path extending part) 25 is provided closer to the ejection port 16A compared to the flow path extending part 26. In the present modification, the flow path extending part 25 extends up to the ejection port 16A in each flow path 17A. In each flow path 17A, the flow path cross-sectional area in a cross section perpendicular to the flow path axis PA (see FIG. 3) is uniform, or approximately uniform, in the extension range of the flow path extending part 25 and in the extension range of the flow path extending part 26. In each flow path 17A, the flow path cross-sectional area in the first flow path extending part (second flow path extending part) 25 is smaller than the flow path cross-sectional area of the flow path extending part (flow path extending part) 26.

In each flow path 17A, the flow path cross-section changing part 27 is formed between the flow path extending parts 25 and 26. In each flow path 17A, the end of the side where the storage cavity 13 is located in the flow path extending part 25 is connected to the flow path cross-section changing part 27, and the end of the side where the ejection port 16A is located in the flow path extending part 26 is connected to the flow path cross-section changing part 27. In each flow path 17A, the flow path cross-sectional area decreases in the flow path cross-section changing part 27 toward the flow path extending part 25. Therefore, in the present modification, the flow path cross-section changing part 27 is formed in each flow path 17A as an area in which the flow path cross-sectional area decreases toward the ejection port 16A.

Also in the present modification, the upper end U1 of the connecting part 18A of each flow path 17A is located either at the same height as the upper end U2 of the storage cavity 13 or on the upper side of the vertical direction with respect to the upper end U2 of the storage cavity 13. For this reason, in the present modification, similarly to the foregoing embodiments, etc., residual air in the storage cavity 13 can be appropriately prevented in each spinning head 2.

In the present modification, a horizontal part 28 which extends horizontally is formed on the flow path upper surface 23 in each flow path 17A. In the example of FIG. 5, etc., the horizontal part 28 is adjacent to the flow path cross-section changing part 27 from the upper side of the vertical direction in each flow path 17A. In each flow path 17A, the entirety of the part other than the horizontal part 28 in the flow path upper surface 23 is tilted with respect to a horizontal plane, and extends upward in the vertical direction as it is closer to the ejection port 16A. Since the flow path 17A is formed in the above-described manner, the flow path upper surface 23 of each flow path 17A is constituted only by the tilted part that is tilted with respect to the horizontal plane in such a manner that it extends upward in the vertical direction as it is closer to the ejection port 16A, and the horizontal part 28 extending horizontally. For this reason, also in the present modification, in the flow path upper surface 23 of each flow path 17A, there is no part extending toward the lower side of the vertical direction as being closer to the ejection port 16A. Therefore, in the present modification, residual air in each flow path 17A can be appropriately prevented, as well as residual air in the storage cavity 13.

In the present modification, in each flow path 17A, the upper end U3 of the connecting part of the flow path extending part 25 to the flow path cross-section changing part 27 is constituted by the flow path upper surface 23. In each flow path 17A, the upper end U3 of the connecting part of the flow path extending part 25 to the flow path cross-section changing part 27 is located at the location of the boundary between the flow path extending part 25 and the flow path cross-section changing part 27 in the flow path upper surface 23. In each flow path 17A, the upper end U4 of the flow path cross-section changing part 27 and the upper end U5 of the flow path extending part 26 are formed by the flow path upper surface 23. In the example of FIG. 5, etc., in each flow path 17A, the upper end U4 of the flow path cross-section changing part 27 is located in the horizontal part 28 of the flow path upper surface 23. Then, in each flow path 17A, the upper end U5 of the flow path extending part 26 is located at the location of the boundary between the flow path extending part 26 and the flow path cross-section changing part 27 in the flow path upper surface 23.

In each flow path 17A, the upper end U3 of the connecting part of the flow path extending part 25 to the flow path cross-section changing part 27 is located either at the same height as the upper end U4 of the flow path cross-section changing part 27 and the upper end U5 of the flow path extending part 26 or on the upper side of the vertical direction with respect to the upper end U4 of the flow path cross-section changing part 27 and the upper end U5 of the flow path extending part 26. For this reason, if a virtual horizontal plane Tβ passing the upper end U3 in each flow path 17A is defined, each of the upper end U4 and the upper end U5 is located either on the horizontal plane Tβ or on the lower side of the vertical direction relative to the horizontal plane T. In the example of FIG. 5, etc., in each flow path 17A, the upper end U3 of the connecting part of the flow path extending part 25 to the flow path cross-section changing part 27 is at the same height as the upper end U4 of the flow path cross-section changing part 27. Furthermore, in each flow path 17A, the upper end U3 of the connecting part of the flow path extending part 25 to the flow path cross-section changing part 27 is located on the upper side of the vertical direction with respect to the upper end U5 of the flow path extending part 26.

Since the flow path extending parts 25 and 26 and the flow path cross-section changing part 27 are formed as described above, the flow path upper surface 23 can be constituted only by the above-described horizontal part 28 and the tilted part in each flow path 17A, even if the flow path cross-section changing part 27 in which the flow path cross-sectional area decreases toward the side on which the ejection port 16A is located is formed. In other words, it is possible to appropriately realize a configuration in which each flow path 17A does not include a part extending downward in the vertical direction as being closer to the ejection port 16A, even if the flow path cross-section changing part 27 is formed.

In the second modification shown in FIG. 6, in the spinning head 2, the head main body 11 is filled with a member 31 separated from the head main body 11. In the inside of the head main body 11, the above-described storage cavity 13 is formed by the head main body 11 and the member 31. In the present modification, a part of the cavity peripheral surface 15 is formed by the member 31. The member 31 forms the cavity upper surface 22, and is adjacent to the storage cavity 13 from the upper side of the vertical direction. Even in the present modification, the upper end U2 of the storage cavity 13 is constituted by the cavity upper surface 22. Then, also in the present modification, the upper end U1 of the connecting part 18A of each flow path 17A to the storage cavity 13 is located either at the same height with respect to the upper end U2 of the storage cavity 13 or on the upper side of the vertical direction with respect to the upper end U2 of the storage cavity 13.

In the third modification illustrated in FIG. 7, etc., in the spinning head 2, the center axis of the storage cavity 13 is deviated from the longitudinal axis (center axis) C of the head main body 11. Even in the present embodiment, the storage cavity 13 is formed along the axial direction of the head main body 11. Also in the present modification, the upper end U2 of the storage cavity 13 is constituted by the cavity upper surface 22. Then, also in the present modification, the upper end U1 of the connecting part 18A of each flow path 17A to the storage cavity 13 is located either at the same height as the upper end U2 of the storage cavity 13 or on the upper side of the vertical direction with respect to the upper end U2 of the storage cavity 13.

In any of the foregoing modifications, the upper end U1 of the connecting part 18A of each flow path 17A is located either at the same height as the upper end U2 of the storage cavity 13 or on the upper side of the vertical direction with respect to the upper end U2 of the storage cavity 13. Thus, similarly to the first embodiment, etc., residual air in the storage cavity 13 can be appropriately prevented in the spinning head 2.

In another modification, no nozzles 12B are provided and no flow paths 17B are formed in each spinning head 2. It suffices that the number of nozzles 12A provided in each spinning head 2 is one or more and that one or more flow paths 17A are formed in each spinning head 2. In any case, the flow path 17A is tilted with respect to a horizontal plane, with the ejection port 16A being located at the upper side of the vertical direction relative to the connecting part 18A to the storage cavity 13. The upper end U1 of the connecting part 18A of the flow path 17A to the storage cavity 13 is located either at the same height as the upper end U2 of the storage cavity 13 or on the upper side of the vertical direction with respect to the upper end U2 of the storage cavity 13. Thus, similarly to the foregoing embodiments, etc., residual air in the storage cavity 13 can be appropriately prevented in the spinning head 2.

According to at least one of the foregoing embodiments or modifications, the ejection port is located on the upper side of the vertical direction with respect to the connecting part to the storage cavity, and at least a part of the flow path is tilted with respect to a horizontal plane. Furthermore, the upper end of the connecting part of the flow path to the storage cavity is located either at the same height as the upper end of the storage cavity or on the upper side of the vertical direction with respect to the upper end of the storage cavity. Thus, it is possible to provide a spinning head and a spinning apparatus including the spinning head that is capable of appropriately preventing residual air in the storage cavity so as to achieve stable spinning, even when the flow path is tilted with respect to a horizontal plane in such a manner that the ejection port is located at the upper side of the vertical direction with respect to the connecting part to the storage cavity.

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.

SPINNING HEAD AND SPINNING APPARATUS

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