Electrospinning apparatus and method for cleaning an electrospinning head in an electrospinning apparatus

Abstract

To provide an electrospinning head that is efficiently and adequately cleaned.SOLUTION: An electrospinning head has a nozzle and an uneven surface. The nozzle is formed of a conductive material. A channel is formed inside the nozzle. An ejection port capable of ejecting raw material liquid fed in the channel is formed on an external surface of the nozzle. The uneven surface is formed near the ejection port on the external surface of the nozzle so as to be uneven state along extending direction of the channel across the whole circumference in circumferential direction of the nozzle.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment of the present invention is , electric A field spinning device, and Electrospinning equipment A method for cleaning an electrospinning head. [Background technology]

[0002] There is an electrospinning apparatus that deposits fine fibers on the surface of a collector or a substrate by electrospinning (sometimes called electric charge spinning, etc.) to form a fiber film. In the electrospinning apparatus, a raw material liquid containing a polymeric material is supplied to an electrospinning head equipped with a nozzle. Then, a voltage is applied to the nozzle, and the raw material liquid is supplied to the electrospinning head, whereby the raw material liquid is charged, and the charged raw material liquid is ejected from the nozzle outlet toward the surface of the collector or substrate. As a result, fibers are deposited on the surface of the collector or substrate.

[0003] As described above, when the fiber membrane is formed by the electrospinning apparatus, the fibers, droplets of the raw material liquid, and polymeric materials of the raw material liquid may adhere to the outer surface of the nozzle near the nozzle outlet. For this reason, after the fiber membrane is formed, the electrospinning head is cleaned by removing the adhesions from the nozzle. In the electrospinning apparatus, it is required that the cleaning of the electrospinning head, such as removing the adhesions from the nozzle, be performed efficiently and appropriately. In other words, it is required that the electrospinning head be cleaned efficiently and appropriately. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-202169 A [Patent Document 2] Japanese Patent Application Publication No. 6-246210 [Patent Document 3] JP 2001-205160 A Summary of the Invention [Problem to be solved by the invention]

[0005] The problem that the present invention aims to solve is to Electrospinning head Cleaned R Field spinning device and its Electrospinning equipment A method for cleaning an electrospinning head is provided. [Means for solving the problem]

[0007] According to an embodiment, an electrospinning apparatus , electric Field spinning head, feeding section, Suction head, suction drive unit and a control unit. The electrospinning head includes a nozzle made of a conductive material, the nozzle having a flow path formed therein and a nozzle formed on an outer surface thereof for ejecting the raw material liquid supplied to the flow path. The supply unit supplies the raw material liquid to the electrospinning head. The suction head is made of an electrically insulating material and has a suction port. The suction drive unit is driven to suck the liquid from the suction port of the suction head. The control unit brings the suction head close to the electrospinning head from the side where the nozzle is open when the raw material liquid is not supplied from the supply unit to the electrospinning head, and drives the suction drive unit when the suction head is close to the electrospinning head. The nozzle of the electrospinning head has an uneven surface formed near the nozzle on the outer surface, and the uneven surface is formed in an uneven shape along the extension direction of the flow path over the entire circumferential direction of the nozzle. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a state in which a fiber membrane is being formed in the electrospinning apparatus according to the first embodiment. [Diagram 2] FIG. 2 is a schematic view showing a state in which the electrospinning head is being cleaned in the electrospinning apparatus according to the first embodiment. [Diagram 3] FIG. 3 is a perspective view that illustrates a schematic configuration of a nozzle of the electrospinning head according to the first embodiment. [Figure 4] FIG. 4 is a schematic diagram showing one of the nozzles and the suction head in a state in which suction is being performed by the suction head and the suction unit of the electrospinning apparatus according to the first embodiment. [Diagram 5] FIG. 5 is a flow chart showing an example of a process performed by the control unit of the electrospinning apparatus according to the first embodiment during formation of a fiber film. [Figure 6] FIG. 6 is a flowchart showing an example of a process performed by the control unit of the electrospinning apparatus according to the first embodiment when cleaning the electrospinning head. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments will be described with reference to the drawings.

[0011] (First embodiment) 1 and 2 show an example of an electrospinning apparatus 1 according to the first embodiment. As shown in Fig. 1 and 2, the electrospinning apparatus 1 includes an electrospinning head 2, a raw material liquid supply unit 3, a power source 4, a collector 5, a suction head 6, a suction unit 7, a head moving unit 8, a control unit 9, and a user interface 10.

[0012] The electrospinning head 2 includes a head body 11 and one or more (four in this embodiment) nozzles 12. Here, a central axis of the head body 11 (electrospinning head 2) is defined, and a direction along the central axis of the head body 11 is defined as a longitudinal direction. The head body 11 extends along the central axis and along the longitudinal direction. In this embodiment, each of the head body 11 and the nozzles 12 is made of a conductive material. The number of the nozzles 12 is not particularly limited, and one or more nozzles 12 may be provided. In addition, each of the head body 11 and the nozzles 12 is preferably made of a material having resistance to the raw material liquid, for example, made of stainless steel.

[0013] Each of the nozzles 12 is provided on the outer peripheral surface of the head body 11. Each of the multiple nozzles 12 protrudes from the outer peripheral surface of the head body 11 toward the outer peripheral side, i.e., toward the side away from the central axis of the head body 11. In this embodiment, the multiple nozzles 12 are arranged at the same or approximately the same angular positions relative to each other around the central axis of the head body 11. Therefore, in this embodiment, the multiple nozzles 12 are arranged along the longitudinal direction of the electrospinning head 2 to form one nozzle row. Note that in Figures 1 and 2, the electrospinning head 2 is shown as viewed from a direction intersecting the central axis (longitudinal direction) and intersecting the protruding direction of the nozzles 12.

[0014] An internal cavity 13 is formed inside the head body 11. The internal cavity 13 is formed along the longitudinal direction (central axis) of the electrospinning head 2. In addition, a flow path 15 is formed inside each of the nozzles 12. In each of the nozzles 12, the flow path 15 extends along the protruding direction from the head body 11. Therefore, in each of the nozzles 12, the extending direction of the flow path 15 coincides or approximately coincides with the protruding direction from the head body 11. One end (inner peripheral end) of each of the flow paths 15 is connected to the internal cavity 13.

[0015] The other end (outer peripheral end) of each of the flow paths 15 is formed with a jet outlet 16. In each of the nozzles 12, the jet outlet 16 is formed on the outer surface. In this embodiment, in each of the nozzles 12, the jet outlet 16 is formed at the end (tip) protruding from the head body 11. Each of the flow paths 15 opens to the outside of the electrospinning head 2 at the jet outlet 16. In each of the nozzles 12, the jet outlet 16 communicates with the internal cavity 13 of the head body 11 through the flow path 15. Therefore, each of the nozzles 12 can eject the raw material liquid supplied to the flow path 15 through the internal cavity 13 from the jet outlet 16. Each of the nozzles 12 can eject the raw material liquid toward the side protruding from the head body 11, i.e., toward the side where the jet outlet 16 opens.

[0016] FIG. 3 shows one configuration of the nozzle 12. As shown in FIG. 1 to FIG. 3, each of the nozzles 12 includes a nozzle base 21 and a needle portion 22. In each of the nozzles 12, the nozzle base 21 is connected to the head body 11 and forms the root of the protruding portion from the head body 11. In each of the nozzles 12, the needle portion 22 further protrudes from the nozzle base 21 toward the outer periphery of the electrospinning head 2 and forms the protruding end from the head body 11. Therefore, in each of the nozzles 12, the nozzle 16 is formed in the needle portion 22. In each of the nozzles 12, the outer diameter of the needle portion 22 is smaller than the outer diameter of the nozzle base 21. In each of the nozzles 12, the area surrounded by the outer periphery of the needle portion 22 in a cross section perpendicular or approximately perpendicular to the extension direction of the flow path 15 is smaller than the area surrounded by the outer periphery of the nozzle base 21.

[0017] In addition, in each of the nozzles 12, a central axis (nozzle central axis) N is defined. In each of the nozzles 12, the central axis N is along the extension direction of the flow path 15 and is coaxial or approximately coaxial with the central axis of the flow path 15. In each of the nozzles 12, a circumferential direction (direction indicated by arrows R1 and R2) which is a direction around the central axis N is defined. In the outer surface of each of the nozzles 12, an uneven surface 23 is formed on the needle portion 22. In each of the nozzles 12, the uneven surface 23 is formed from the protruding end toward the inner periphery of the electrospinning head 2, and is formed at the protruding end and in the vicinity of the protruding end. Therefore, in each of the nozzles 12, the uneven surface 23 is formed in the vicinity of the nozzle outlet 16. In each of the nozzles 12, the uneven surface 23 is formed in an uneven shape along the extension direction of the flow path 15 (the protruding direction from the head body 11). Further, the uneven surface 23 is formed over the entire circumference in the circumferential direction (around the central axis N) of each of the nozzles 12. Therefore, in the uneven surface 23 of each of the nozzles 12, each of the convex portions and concave portions is formed in a ring shape.

[0018] The supply unit 3 of the raw material liquid can supply the raw material liquid to the electrospinning head 2. The supply unit 3 constitutes a supply source of the raw material liquid and a supply path of the raw material liquid from the supply source to the electrospinning head 2. As shown in Fig. 1 etc., the supply unit 3 of the raw material liquid includes a storage unit 31, a supply drive unit 32, a supply adjustment unit 33, and a supply pipe 35. Each of the storage unit 31, the supply drive unit 32, the supply adjustment unit 33, and the supply pipe 35 is resistant to the raw material liquid, and in one example, each of the storage unit 31 and the supply pipe 35 is made of an electrically insulating material such as a fluororesin.

[0019] The storage unit 31 is a tank or the like that stores the raw material liquid. The raw material liquid is a polymer material dissolved in a solvent. The polymer contained in the raw material liquid and the solvent that dissolves the polymer are appropriately determined according to the type of the fiber 20 to be deposited on the surface of the collector 5. The polymer material is not particularly limited and can be appropriately changed according to the material of the fiber 20 to be formed. For example, polypropylene, polyethylene, polystyrene, polyethylene terephthalate, polyvinyl chloride, polycarbonate, nylon, aramid, polyimide, polyamideimide, etc. can be used as the polymer material. The solvent used in the raw material liquid may be any one that can dissolve the polymer material. The solvent can be appropriately changed according to the polymer material to be dissolved. For example, water, methanol, ethanol, isopropyl alcohol, acetone, benzene, toluene, N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc), etc. can be used as the solvent.

[0020] The supply pipe 35 connects the storage unit 31 and the electrospinning head 2 to form a supply flow path for the raw material liquid. The supply drive unit 32 is driven to supply the raw material liquid from the storage unit 31 through the supply pipe 35 to the electrospinning head 2. In one example, the supply drive unit 32 is a pump. The supply adjustment unit 33 adjusts the flow rate and pressure of the raw material liquid supplied to the electrospinning head 2. In one example, the supply adjustment unit 33 includes a control valve capable of controlling the flow rate and pressure of the raw material liquid. In this case, the supply adjustment unit 33 adjusts the raw material liquid to an appropriate flow rate and pressure based on the viscosity of the raw material liquid and the structure of the nozzle 12. In another example, the supply adjustment unit 33 can switch between supplying and stopping the supply of the raw material liquid from the storage unit 31 to the electrospinning head 2. In this case, the supply adjustment unit 33 includes, for example, a switching valve.

[0021] As shown in Figures 1 and 2, the power source 4 can apply a voltage to the electrospinning head 2. When a voltage is applied to the electrospinning head 2, a voltage of a predetermined polarity is applied to each of the nozzles 12 via the head body 11. A voltage of the same polarity is applied to the multiple nozzles 12. When a voltage is applied to the electrospinning head 2 by the power source 4 as described above and the raw material liquid is supplied to the electrospinning head 2 by the supply unit 3, the raw material liquid is charged to the same polarity as the nozzle 12 (electrospinning head 2).

[0022] In one example, terminals (not shown) electrically connected to each of the nozzles 12 may be provided, and the power source 4 may apply a voltage to each of the nozzles 12 via the terminals. In this case, it is not necessary to form the head body 11 from a conductive material. The polarity of the voltage applied to each of the nozzles 12 may be positive or negative. In one example such as FIG. 1 and FIG. 2, the power source 4 is a DC power source, and applies a positive voltage to each of the nozzles 12.

[0023] The collector 5 is made of a conductive material. The collector 5 is resistant to the raw material liquid, and in one example, is made of stainless steel. As shown in FIG. 1, etc., the collector 5 is disposed on the side of the electrospinning head 2 where the nozzle 12 protrudes, and on the side of the electrospinning head 2 where the ejection port 16 opens. Therefore, the collector 5 is disposed on the side of the electrospinning head 2 where the raw material liquid is ejected from the nozzle 12. In one example in FIG. 1, etc., the collector 5 is grounded, and the voltage of the collector 5 to the ground is 0V or approximately 0V. In another example, a voltage of the opposite polarity to the raw material liquid and the electrospinning head 2 (nozzle 12) is applied to the collector 5 by the power source 4 or a power source other than the power source 4.

[0024] In this embodiment, a voltage is applied to the electrospinning head 2, and the raw material liquid is supplied to the electrospinning head 2, so that the raw material liquid is charged to the same polarity as the electrospinning head 2. When the raw material liquid is charged to the same polarity as the electrospinning head 2, the raw material liquid is ejected from each nozzle 16 of the nozzle 12 toward the collector 5 due to the potential difference between the raw material liquid of the electrospinning head 2 (nozzle 12) and the collector 5. When the raw material liquid is ejected from the electrospinning head 2 toward the collector 5, the fibers 20 are deposited on the surface of the collector 5, and the deposited fibers 20 form a film of the fibers 20. That is, the film of the fibers 20 is formed by the electrospinning method (sometimes referred to as the charge-induced spinning method, etc.). The voltage applied to the nozzle 12 (electrospinning head 2) and the voltage applied to the collector 5 are adjusted to an appropriate magnitude according to the type of polymer material contained in the raw material liquid and the distance of the electrospinning head 2 to the collector 5. FIG. 1 also shows a state in which a film of the fiber 20 is being formed, with the suction unit 7 omitted.

[0025] The collector 5 is formed, for example, in a plate or sheet shape. When the collector 5 is formed in a sheet shape, the fibers 20 may be deposited on the collector 5 wound around the outer circumferential surface of a roll or the like. The collector 5 may be movable. In one example, a pair of rotating drums and a drive source for driving the rotating drums are provided. The rotating drums are driven by the drive source, so that the collector 5 moves between the pair of rotating drums in the same manner as a belt conveyor. The movement (transportation) of the collector 5 makes it possible to change the area on the surface of the collector 5 where the fibers 20 are deposited over time. The film of the fibers 20 formed on the surface of the collector 5 is removed from the collector 5. The film of the fibers 20 is used, for example, in nonwoven fabrics and filters, but is not limited thereto.

[0026] In one example, the collector 5 is not provided. In this case, a substrate made of a conductive material is used. Then, as described above, a voltage is applied to the electrospinning head 2, and the raw material liquid is supplied to the electrospinning head 2, so that the raw material liquid is ejected from each of the ejection ports 16 of the nozzle 12 toward the substrate. As a result, the fibers 20 are deposited on the surface of the substrate, and a film of the fibers 20 is formed on the surface of the substrate. In this case, the substrate may be grounded, and a voltage of the opposite polarity to that of the electrospinning head 2 (nozzle 12) and the raw material liquid may be applied to the substrate by the power source 4 or a power source other than the power source 4.

[0027] In another example, a substrate is placed on the collector 5. Then, as described above, a voltage is applied to the electrospinning head 2, and the raw material liquid is supplied to the electrospinning head 2, whereby the raw material liquid is ejected from each of the ejection ports 16 of the nozzle 12 toward the collector 5 and the substrate. As a result, the fibers 20 are deposited on the surface of the substrate placed on the collector 5, and a film of the fibers 20 is formed on the surface of the substrate. In this case, even if the substrate has electrical insulation properties, it is possible to form a film of the fibers 20 on the surface of the substrate.

[0028] In addition, when the substrate is placed on the collector 5, the substrate may be movable on the collector 5. In one example, a rotating drum on which a sheet-shaped substrate is wound and a rotating drum for winding up the substrate on which a film of the fibers 20 is formed are provided. The substrate moves on the collector 5 by rotating each of the rotating drums. By moving (transporting) the substrate, it becomes possible to change the area on the surface of the substrate where the fibers 20 are deposited over time. An example of forming a film of the fibers 20 on the surface of the substrate is, but is not limited to, the manufacture of a separator-integrated electrode for a battery. In this case, one of the negative electrode and the positive electrode of the electrode group is used as the substrate. The film of the fibers 20 formed on the surface of the substrate becomes a separator integrated with the negative electrode or the positive electrode.

[0029] In the electrospinning apparatus 1, when the work of forming the film of the fiber 20 is performed as described above, the fiber 20, droplets of the raw material liquid, and polymeric material of the raw material liquid may adhere as adhesions to the outer surface of each nozzle 12 near the nozzle outlet 16. For this reason, after the work of forming the film of the fiber 20 is performed, the electrospinning head 2 is cleaned by removing adhesions to the nozzle 12, etc. The suction head 6 and the suction unit 7 are used for cleaning the electrospinning head 2. FIG. 2 shows the state in which the electrospinning head 2 is being cleaned, with the supply unit 3 and the collector 5 omitted. The suction head 6 and the suction unit 7 suck adhesions to the nozzle 12 during the cleaning work of the electrospinning head 2.

[0030] FIG. 4 shows one of the nozzles 12 and the suction head 6 in a state where suction is being performed by the suction head 6 and the suction unit 7. As shown in FIG. 1, FIG. 2, FIG. 4, etc., the suction head 6 is formed in a cylindrical shape, and a suction cavity 61 is formed therein. The suction cavity 61 opens to the outside of the suction head 6 at a suction port 62. The suction head 6 is formed of an electrically insulating material, for example, an electrically insulating resin. The suction head 6 includes head components 63 and 65. In one example shown in FIG. 2, FIG. 4, etc., the head component (first head component) 63 has a larger outer diameter than the head component (second head component) 65. In addition, the suction head 6 has a suction port 62 formed at the end of the head component 63 opposite to the head component 65.

[0031] The suction unit 7 constitutes a suction source for suction from the suction port 62 of the suction head 6, and a suction path from the suction head 6 to the suction source. As shown in Fig. 2 etc., the suction unit 7 includes a suction drive unit 71, a recovery unit 72, and a suction pipe 73. The suction drive unit 71 is driven or the like to suck the suction object through the suction port 62 of the suction head 6. As described above, when the suction drive unit 71 is driven (suction drive), a suction force is applied from the outside of the suction head 6 through the suction port 62 to the suction cavity 61. The suction drive unit 71 is a pump, a blower, or the like.

[0032] The collection unit 72 is a tank or the like that stores the aspirated material sucked through the suction port 62. In the suction unit 7, a filter (not shown) or the like is provided between the suction drive unit 71 and the collection unit 72 to prevent the aspirated material from flowing into the suction drive unit 71. The suction piping 73 connects the suction head 6 and the collection unit 72, and forms a suction flow path for the aspirated material. As shown in FIG. 4 and other figures, in the suction head 6, the suction piping 73 is connected to the head configuration unit 65 from the side opposite to the suction port 62.

[0033] The head moving unit 8 constitutes a mechanism for moving the suction head 6 relative to the electrospinning head 2 and the like. Here, in the electrospinning device 1, a first direction (direction indicated by arrows X1 and X2), a second direction (direction indicated by arrows Y1 and Y2) intersecting (perpendicular or approximately perpendicular) with the first direction, and a third direction (direction perpendicular or approximately perpendicular to the paper surface in Figs. 1 and 2) intersecting (perpendicular or approximately perpendicular) with both the first direction and the second direction are defined. In one example, the third direction coincides or approximately coincides with the vertical direction. The suction head 6 can be moved in the first direction by the head moving unit 8. In addition, the suction head 6 can be moved in at least one of the second direction and the third direction by the head moving unit 8.

[0034] In one example shown in Figs. 1 and 2, the longitudinal direction of the electrospinning head 2 coincides or approximately coincides with the first direction. Therefore, the arrangement direction of the nozzles 12 in the nozzle row coincides or approximately coincides with the first direction. In one example shown in Figs. 1 and 2, each of the nozzles 12 protrudes toward one side of the second direction (the arrow Y1 side), and each of the flow paths 15 opens toward one side of the second direction (the arrow Y1 side) at the nozzle 16. Therefore, in each of the nozzles 12, the raw material liquid is ejected from the nozzle 16 toward one side of the second direction.

[0035] The head moving unit 8 includes a moving drive unit 81 and a driving force transmission unit 82. The moving drive unit 81 includes a driving member such as an electric motor, and the driving member is driven by the supply of electric power. The driving force transmission unit 82 connects the moving drive unit 81 and the suction head 6. The driving force transmission unit 82 transmits the driving force generated by the driving member of the moving drive unit 81 to the suction head 6, thereby moving the suction head 6. Here, when the suction head 6 is movable in two directions, two driving members are provided in the moving drive unit 81, and when the suction head 6 is movable in three directions, three driving members are provided in the moving drive unit 81. In addition, the multiple driving members do not need to be arranged in one moving drive unit 81, and in one example, the multiple driving members that move the suction head 6 may be arranged at positions separated from each other.

[0036] Since the head moving unit 8 is provided as described above, the suction head 6 can be moved to a position close to the electrospinning head 2 shown in FIG. 2 and the like. The suction head 6 approaches the electrospinning head 2 from the side where each of the nozzles 12 has an opening, that is, from one side in the second direction (the side indicated by the arrow Y1). Furthermore, since the head moving unit 8 is provided, the suction head 6 can be moved to a position away from the electrospinning head 2 shown in FIG. 1 and the like. In the state shown in FIG. 1, the suction head 6 is disposed away from the electrospinning head 2 in the second direction, and the collector 5 is located between the suction head 6 and the electrospinning head 2 in the second direction. In addition, in the state where the suction head 6 has moved to a position away from the electrospinning head 2, the suction head 6 may be located away from the electrospinning head 2 in the second direction as shown in FIG. 1 and the like, or the suction head 6 may be located away from the electrospinning head 2 in the third direction. In addition, in a state where the suction head 6 has been moved to a position away from the electrospinning head 2, the suction head 6 may be positioned away from the electrospinning head 2 in both the second direction and the third direction.

[0037] The control unit (controller) 9 is, for example, a computer. The control unit 9 includes a processor or 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 such as a memory. The control unit 9 may include only one integrated circuit or multiple integrated circuits. The control unit 9 performs processing by executing a program stored in a storage medium or the like. The control unit 9 controls the drive of the supply drive unit 32, the operation of the supply adjustment unit 33, the output from the power source 4, and the drive of the suction drive unit 71. The control unit 9 also controls the drive of the movement drive unit 81 to control the movement of the suction head 6 and adjust the position of the suction head 6.

[0038] When forming a film of the fiber 20 by the electrospinning method, the control unit 9 controls the driving of the movement drive unit 81 to move the suction head 6 to a position away from the electrospinning head 2. Then, in a state in which the suction head 6 is located at a position away from the electrospinning head 2, the control unit 9 applies a voltage from the power source 4 to the nozzle 12. Then, the control unit 9 controls the driving of the supply drive unit 32, etc., to supply the raw material liquid to the electrospinning head 2. As a result, the charged raw material liquid is ejected from each ejection port 16 of the nozzle 12, and a film of the fiber 20 is formed.

[0039] When cleaning the electrospinning head 2, the control unit 9 controls the driving of the movement drive unit 81 to move the suction head 6 to a position close to the electrospinning head 2. At this time, the suction head 6 approaches the electrospinning head 2 from the side where each of the nozzles 12 has an opening. The control unit 9 also controls the driving of the supply drive unit 32, etc., to maintain a state in which the raw material liquid is not supplied to the electrospinning head 2. Then, in a state in which the suction head 6 is located at a position close to the electrospinning head 2 and the raw material liquid is not supplied from the supply unit 3 to the electrospinning head 2, the control unit 9 applies a voltage from the power source 4 to the nozzle 12 and drives (suction drive) the suction drive unit 71. As a result, as shown in FIG. 4 and the like, the adhesion to the nozzle 12 is charged, and the charged adhesion is sucked into the suction cavity 61 through the suction port 62. Then, the adhesion (suctioned material) sucked into the suction cavity 61 is collected in the collection unit 72 through the suction piping 73.

[0040] In addition, when the suction drive unit 71 is driven and suction is performed through the suction port 62, the control unit 9 controls the drive of the movement drive unit 81 to reciprocate the suction head 6 along the arrangement direction of the multiple nozzles 12 (the direction indicated by the arrows X1 and X2). At this time, the suction head 6 reciprocates between positions B1 and B2 in FIG. 2. Here, the nozzles 12α and 12β located at both ends in the arrangement direction among the multiple nozzles 12 forming the nozzle row are defined. The suction head 6 moves to a position B1 outside the nozzle 12α in the arrangement direction of the nozzles 12. Then, the suction head 6 moves to a position B2 outside the nozzle 12β in the arrangement direction of the nozzles 12. In this embodiment, a voltage is applied to the electrospinning head 2 from the same power source 4 when forming a film of the fiber 20 and when cleaning the electrospinning head 2. However, in one example, the power supply that applies voltage to the electrospinning head 2 when forming the membrane of the fiber 20 and the power supply that applies voltage to the electrospinning head 2 when cleaning the electrospinning head 2 may be different.

[0041] The user interface 10 includes an operation member. An operation command to start forming a film on the fiber 20, an operation command to end forming a film on the fiber 20, an operation command to start cleaning the electrospinning head 2, and an operation command to end cleaning the electrospinning head 2 are input by an operator or the like through the operation member. Examples of the operation member include a button, a dial, a display, and a touch panel. The control unit 9 performs control based on the operation command input through the operation member. The user interface 10 may also include a notification unit that notifies an operator or the like of information. In this case, the control unit 9 causes the notification unit to notify an operator or the like of information that needs to be notified. The notification unit notifies by displaying a screen, emitting a sound, turning on a light, and the like.

[0042] 5 shows an example of a process performed by the control unit 9 when forming a film of the fiber 20. When an operation command to start forming a film of the fiber 20 is input by an operation member of the user interface 10 or the like, the control unit 9 controls the driving of the movement driving unit 81 to move the suction head 6 to a position away from the electrospinning head 2 (S101). Then, the control unit 9 applies a voltage from the power source 4 to the electrospinning head 2 (S102). Then, the control unit 9 drives the supply driving unit 32 or the like to supply the raw material liquid to the electrospinning head 2 (S103). As a result, the charged raw material liquid is ejected from each ejection port 16 of the nozzle 12, and a film of the fiber 20 is formed.

[0043] Then, the control unit 9 judges whether or not an operation command to end the formation of the film on the fiber 20 has been input by an operating member of the user interface 10 or the like (S104). If an operation command to end the formation of the film on the fiber 20 has not been input (S104-No), the process returns to S102. Then, the control unit 9 sequentially performs the processes from S102 onward. On the other hand, if an operation command to end the formation of the film on the fiber 20 has been input (S104-Yes), the control unit 9 stops the supply of the raw material liquid to the electrospinning head 2 by, for example, stopping the drive of the supply drive unit 32 (S105). Then, the control unit 9 stops the application of voltage from the power source 4 to the electrospinning head 2 (S106). This causes the raw material liquid to not be ejected from each ejection port 16 of the nozzle 12.

[0044] FIG. 6 shows an example of a process performed by the control unit 9 when cleaning the electrospinning head 2. When an operation command to start cleaning the electrospinning head 2 is input by an operation member of the user interface 10 or the like, the control unit 9 controls the driving of the movement driving unit 81 to move the suction head 6 to a position close to the electrospinning head 2 (S111). Then, the control unit 9 maintains a state in which the supply of the raw material liquid to the electrospinning head 2 is stopped by maintaining a state in which the driving of the supply driving unit 32 is stopped (S112). Then, the control unit 9 applies a voltage from the power source 4 to the electrospinning head 2 in a state in which the raw material liquid is not supplied to the electrospinning head 2 (S113), and drives the suction driving unit 71 (suction drive) (S114). As a result, the deposit on the nozzle 12 is charged, and the charged deposit is sucked into the suction cavity 61 through the suction port 62. Furthermore, while the suction drive unit 71 is being driven, the control unit 9 controls the driving of the movement drive unit 81 to reciprocate the suction head 6 along the arrangement direction of the multiple nozzles 12 (S115).

[0045] Then, the control unit 9 judges whether or not an operation command to end the cleaning of the electrospinning head 2 has been input by an operation member of the user interface 10 or the like (S116). If an operation command to end the cleaning has not been input (S116-No), the process returns to S113. Then, the control unit 9 sequentially performs the processes from S113 onward. On the other hand, if an operation command to end the cleaning has been input (S116-Yes), the control unit 9 stops the application of voltage from the power source 4 to the electrospinning head 2 (S117) and stops the drive (suction drive) of the suction drive unit 71 (S118). This causes the suction port 62 of the suction head 6 to be in a state where suction is not performed. Then, the control unit 9 controls the drive of the movement drive unit 81 to stop the reciprocating movement of the suction head 6 (S119).

[0046] In this embodiment, an uneven surface 23 is formed on the outer surface of each nozzle 12 near the nozzle outlet 16. In each nozzle 12, the uneven surface 23 is formed in an uneven shape along the extension direction of the flow path 15 over the entire circumference in the circumferential direction. Since the uneven surface 23 is formed on each nozzle 12 as described above, even if the fibers 20, the droplets of the raw material liquid, the polymer material of the raw material liquid, and the like adhere to the outer surface of each nozzle 12 near the nozzle outlet 16, the contact area between the adhered matter and the nozzle 12 is small. By reducing the contact area between the adhered matter and the nozzle 12, it becomes easier to properly remove the adhered matter from the nozzle 12. This allows the electrospinning head 2 to be efficiently and properly cleaned.

[0047] In addition, in this embodiment, when cleaning the electrospinning head 2, the control unit 9 applies a voltage from the power source 4 to the nozzle 12 while the raw material liquid is not being supplied to the electrospinning head 2. This causes the deposits on the nozzle 12 to be charged. This makes it easier to remove the deposits on the nozzle 12 more appropriately.

[0048] As described above, in this embodiment, deposits on the nozzles 12 are appropriately removed. Therefore, when forming a film of the fibers 20 after cleaning the electrospinning head 2, the time until the ejection of the raw material liquid from each nozzle 12 becomes stable is shortened. This improves the work efficiency in forming the film of the fibers 20.

[0049] Furthermore, in this embodiment, by driving the suction drive unit 71 while a voltage is applied to the nozzle 12 from the power source 4, the matter adhering to the nozzle 12 is sucked through the suction port 62 and removed from the nozzle 12. Therefore, the matter adhering to the nozzle 12 is removed without the suction head 6 coming into contact with the nozzle 12. Since the matter adhering to the nozzle 12 is removed without the suction head 6 or the like coming into contact with the nozzle 12, damage to the nozzle 12 or the like is effectively prevented.

[0050] In addition, in this embodiment, a solvent or the like that dissolves the polymer material of the fiber 20 and the raw material liquid is not used to remove the deposits on the nozzle 12. Therefore, after cleaning the electrospinning head 2, the solvent or the like does not remain in each flow path 15 of the nozzle 12. Therefore, when forming a film of the fiber 20 after cleaning the electrospinning head 2, the time until the ejection of the raw material liquid from each nozzle 12 becomes stable is further appropriately shortened.

[0051] In this embodiment, the suction head 6 is made of an electrically insulating material. Therefore, even if a voltage is applied to the nozzle 12 during cleaning of the electrospinning head 2, the parts of the suction unit 7, the head moving unit 8, etc. made of a conductive material are effectively prevented from being electrically connected to the nozzle 12 via the suction head 6.

[0052] In this embodiment, while the suction drive unit 71 is being driven, the control unit 9 moves the suction head 6 back and forth along the arrangement direction of the nozzles 12 as described above. Therefore, the deposits are appropriately sucked and removed from any of the arranged nozzles 12.

[0053] (Modification) In a modified example, a rotating brush is used instead of the suction head 6 to remove the deposits on the nozzles 12. In this modified example, the uneven surface 23 is also formed on each of the nozzles 12. In cleaning the electrospinning head 2, the control unit 9 applies a voltage to the nozzles 12 from the power source 4 while the feed unit 3 is not supplying the raw material liquid to the electrospinning head 2. Then, while the voltage is being applied to the nozzles 12, the rotating brush is rotated. Then, while the voltage is being applied to the nozzles 12, the rotating brush is brought into contact with each of the nozzles 12 to remove the deposits on the nozzles 12.

[0054] The number of nozzles 12 and the shape of each of the nozzles 12 are not limited to those in the above-described embodiment. In one modified example, two nozzle rows are formed on the outer peripheral surface of the head body 11 in the electrospinning head 2, and the two nozzle rows are arranged offset from each other around the central axis of the head body 11 (the circumferential direction of the electrospinning head 2). In each of the nozzle rows, a plurality of nozzles 12 are arranged along the arrangement direction of the electrospinning head 2. In another modified example, the electrospinning head 2 is provided with only one nozzle 12.

[0055] However, in any of the modified examples, one or more nozzles 12 are provided in the electrospinning head 2. Each of the nozzles 12 has a flow path 15 formed therein, and an outlet 16 capable of ejecting the raw material liquid supplied to the flow path 15 is formed on the outer surface. An uneven surface 23 is formed in the vicinity of the outlet 16 on the outer surface of each of the nozzles 12. Each of the nozzles 12 has an uneven shape formed along the extension direction of the flow path 15 over the entire circumference.

[0056] According to at least one of these embodiments or examples, an uneven surface is formed on the outer surface of the nozzle near the nozzle outlet, and the uneven surface is formed in an uneven shape along the extension direction of the flow path over the entire circumferential direction of the nozzle, thereby providing an electrospinning head that can be efficiently and appropriately cleaned.

[0057] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. The following are additional notes. [1] a nozzle formed of a conductive material and having a flow path formed therein, the nozzle having an ejection port formed on an outer surface thereof for ejecting a raw material liquid supplied to the flow path; an uneven surface formed in the vicinity of the ejection port on the outer surface of the nozzle and having unevenness along an extension direction of the flow path over the entire circumference of the nozzle in the circumferential direction; 1. An electrospinning head comprising: [2][1] an electrospinning head; A supply unit that supplies the raw material liquid to the electrospinning head; A power source capable of applying a voltage to the nozzle of the electrospinning head; a control unit that applies the voltage from the power source to the nozzle when the raw material liquid is not supplied from the supply unit to the electrospinning head; An electrospinning apparatus comprising: [3] The electrospinning apparatus of [2], wherein the control unit applies the voltage from the power source to the nozzle and supplies the raw material liquid from the supply unit to the electrospinning head, thereby charging the raw material liquid and ejecting the charged raw material liquid from the nozzle outlet. [4] A suction head formed from an electrically insulating material and having a suction port; a suction drive unit that, when driven, causes suction through the suction port of the suction head; The control unit is In a state in which the raw material liquid is not supplied from the supply unit to the electrospinning head, the suction head is brought close to the electrospinning head from the side where the nozzle is opened, In a state where the suction head is close to the electrospinning head, the voltage is applied from the power source to the nozzle, and the suction drive unit is driven. [2] or [3]. [5] The nozzles are a plurality of nozzles arranged in an arrangement direction, Each of the plurality of nozzles has the flow path and the jet outlet, and is provided with the uneven surface; The control unit reciprocates the suction head along the arrangement direction of the plurality of nozzles while the suction head is close to the electrospinning head and the suction drive unit is driven. [4] Electrospinning apparatus. [6] A method for cleaning the electrospinning head according to [1], comprising the steps of: applying a voltage to the nozzle in a state in which the raw material liquid is not supplied to the electrospinning head; removing a deposit on the nozzle while the raw material solution is not supplied to the electrospinning head and the voltage is applied to the nozzle; A cleaning method comprising: [Explanation of symbols]

[0058] 1...electrospinning apparatus, 2...electrospinning head, 3...supply unit, 4...power supply, 5...collection body, 6...suction head, 7...suction unit, 8...head moving unit, 9...control unit, 10...user interface, 11...head body, 12...nozzle, 15...flow path, 16...jet outlet, 23...uneven surface, 61...suction cavity, 62...suction port, 71...suction drive unit

Claims

1. an electrospinning head comprising a nozzle made of a conductive material, a flow path formed inside the nozzle, and a nozzle capable of ejecting a raw material liquid supplied to the flow path formed on an outer surface of the nozzle; A supply unit that supplies the raw material liquid to the electrospinning head; a suction head formed from an electrically insulating material and having a suction port; a suction drive unit that, when driven, causes suction through the suction port of the suction head; a control unit that brings the suction head close to the electrospinning head from the side where the nozzle is opened when the raw material liquid is not being supplied from the supply unit to the electrospinning head, and drives the suction drive unit when the suction head is close to the electrospinning head; Equipped with the nozzle of the electrospinning head comprises an uneven surface formed on the outer surface of the nozzle near the nozzle outlet; The uneven surface is formed in an uneven shape along the extension direction of the flow path over the entire circumferential direction of the nozzle. Electrospinning apparatus.

2. Further comprising a power source capable of applying a voltage to the nozzle of the electrospinning head; The control unit applies the voltage from the power source to the nozzle in a state in which the raw material liquid is not supplied from the supply unit to the electrospinning head.

2. The electrospinning apparatus of claim 1.

3. 3. The electrospinning apparatus of claim 2, wherein the control unit applies the voltage from the power source to the nozzle and supplies the raw material liquid from the supply unit to the electrospinning head, thereby charging the raw material liquid and ejecting the charged raw material liquid from the ejection port of the nozzle.

4. 4. The electrospinning apparatus according to claim 2, wherein the control unit applies the voltage from the power source to the nozzle in parallel with driving the suction drive unit when the suction head is in close proximity to the electrospinning head.

5. The nozzles are a plurality of nozzles arranged in an arrangement direction, Each of the plurality of nozzles has the flow path and the nozzle outlet, and is provided with the uneven surface; The control unit reciprocates the suction head along the arrangement direction of the plurality of nozzles while the suction head is close to the electrospinning head and the suction drive unit is driven.

5. The electrospinning apparatus of claim 4.

6. 2. A method for cleaning the electrospinning head in the electrospinning apparatus of claim 1, comprising: applying a voltage to the nozzle in a state in which the raw material liquid is not supplied to the electrospinning head; In a state where the raw material solution is not supplied to the electrospinning head and the voltage is applied to the nozzle, the suction head is brought close to the electrospinning head and the suction drive unit is driven to remove adhesions to the nozzle; A cleaning method comprising:

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