JP5006862B2 - Nanofiber manufacturing method and manufacturing apparatus - Google Patents

Description

  The present invention relates to a nanofiber manufacturing method and manufacturing apparatus, and more particularly to a technique for manufacturing nanofibers by electrospinning.

  In recent years, the electrospinning method (charge-induced spinning method) has attracted attention because nanofibers, which are fibrous materials having submicron diameters, can be easily produced. In the electrospinning method, a raw material liquid in which a polymer material is dispersed or dissolved in a solvent is released into the air, and at the time of release, the raw material liquid is charged at a high voltage, and the raw material liquid is electrically stretched in the air. This is a method for obtaining nanofibers (see, for example, Patent Document 1).

  More specifically, the raw material liquid charged by an electric field and discharged into the air evaporates the solvent while flying in the air, and the volume decreases. On the other hand, since the charge imparted to the raw material liquid is maintained regardless of the evaporation of the solvent, the charge density of the raw material liquid increases with the evaporation of the solvent. Then, when the coulomb force in the repulsion direction inside the raw material liquid becomes larger than the surface tension of the raw material liquid, a phenomenon occurs that the raw material liquid is explosively stretched linearly (hereinafter referred to as an electrostatic stretching phenomenon). This electrostatic stretching phenomenon occurs continuously in the air, and the raw material liquid is subdivided into a linear shape geometrically, thereby forming fine fibers having a submicron scale diameter.

  Here, Patent Documents 2 and 3 disclose a method of collecting nanofibers generated from a polymer material ejected from a nozzle by depositing them on a collector made of a long strip-like sheet fed in the longitudinal direction. It is shown.

Japanese Patent Laying-Open No. 2005-330624 JP 2006-373295 A JP 2006-283240 A

As shown in Patent Documents 2 and 3, conventionally, a method of collecting nanofibers by being deposited on a long strip-shaped collector that is sent in the longitudinal direction is generally performed. However, this method has the following disadvantages.
First, there is a case where a part of the polymer material discharged from the raw material discharge means such as the nozzle is shifted aside, and all the polymer materials cannot be collected. This causes material loss. In addition, it is necessary to periodically perform the operation of removing the polymer material attached to the other member, and during that time, the manufacturing apparatus must be stopped, and the productivity is lowered. Moreover, since the collection body sent to a longitudinal direction is wound with the polymeric material deposited on the surface, a polymeric material will be pressed and compressed.

Furthermore, when the polymer material deposited on the surface of the collecting body is removed from the collecting body, the material of the collecting body is mixed.
In addition, the electrospinning method is performed by generating a high potential difference between the raw material discharge means and an electrode disposed behind the collector or around the raw material discharge means. At this time, since the raw material discharge means is connected to other members such as a pump through a raw material supply pipe or the like, it is difficult to prevent leakage from the raw material discharge means to the outside. For this reason, a high voltage is not applied to the raw material discharge means, and a high voltage is generally applied to the electrode side.

However, when the fibrous polymer material does not adhere to the collector, for example, adheres to the electrode, the electrode to which the high voltage is applied and the raw material discharge means are conducted through the polymer material. As a result, electric leakage is caused through the raw material discharge means. In order to avoid this, it is necessary to more strictly insulate the raw material discharge means from other members, which increases the cost. In particular, when the polymer material or the solvent mixed with the polymer material has conductivity, a remarkable leakage phenomenon occurs.
Furthermore, the methods described in Patent Documents 2 and 3 require a strip-shaped collecting body and a mechanism (roller, its rotating device, etc.) for feeding it in the longitudinal direction, which makes the device large and reduces the cost. Will increase.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a nanofiber manufacturing method and a manufacturing apparatus capable of reducing manufacturing cost and improving productivity.

The present invention for achieving the above object is a nanofiber manufacturing method in which a liquid material containing a polymer material is charged and discharged into the air, and a fibrous material is generated from the material by an electrostatic stretching phenomenon,
In the nanofiber manufacturing method, the generated fibrous substance is collected by a bag made of a fabric having at least a part of air permeability.

Further, the present invention is a nanofiber manufacturing apparatus for charging a liquid raw material containing a polymer material and discharging it into the air, and generating a fibrous substance from the raw material by an electrostatic stretching phenomenon,
A raw material release means for discharging the raw material into the air, at least a part of which is made of a conductor;
An electrode disposed at a predetermined distance from the raw material discharge means;
A potential difference applying means for providing a potential difference between the raw material discharge means and the electrode so as to generate an electric field between the raw material discharge means and the electrode;
A collecting means for collecting a fibrous material generated from the raw material by an electrostatic stretching phenomenon, and
Provided is a nanofiber manufacturing apparatus in which the collecting means includes a bag made of a fabric having at least a part of air permeability.

In the manufacturing apparatus of the present invention, in a preferred embodiment, the raw material is released from the raw material release means toward the electrode,
There is provided a deflecting means for deflecting the discharged raw material or the fibrous material generated therefrom in a direction different from the discharge direction of the raw material.

  In the manufacturing apparatus of the present invention described above, in another preferred embodiment, the open end of the bag is interposed between the raw material discharge means and the electrode.

  In the manufacturing apparatus of the present invention, in another preferred embodiment, a revolver type bag exchanging means or a slide type bag exchanging means is provided.

In the manufacturing apparatus of the present invention, in another preferred embodiment, the raw material releasing means is
A substantially cylindrical rotary container in which pores for discharging the raw material are formed in the peripheral wall and the raw material is introduced therein, or at least one flat surface, and the raw material is formed on the wall of the surface Is formed from a container into which the raw material is introduced at a predetermined pressure.

  Alternatively, the raw material discharge means is composed of a two-fluid nozzle, and discharges the raw material discharged from at least one hole of the nozzle by atomizing with the gas injected from at least one other hole of the nozzle. .

  In the production apparatus of the present invention, in another preferred embodiment, at least one of the polymer material and the liquid component constituting the raw material has conductivity.

  The deflecting unit may include an airflow generating unit that generates an airflow by at least one of air blowing and suction. At this time, it is more preferable that a flow rate measuring unit for measuring the flow rate of the air flow by the air flow generating unit is provided, and a control unit for controlling the bag replacing unit based on a measurement result of the flow rate measuring unit.

  According to the present invention, since the fibrous material generated by the electrostatic stretching phenomenon from the raw material released by the raw material discharging means is collected by the bag made of a fabric having at least a part of air permeability, the fibrous material It is possible to collect without missing. Thereby, it can prevent that a raw material etc. adhere to another member. Therefore, the maintenance frequency can be reduced and the productivity can be improved.

In particular, when the raw material is discharged toward the electrode for inducing charge to the raw material discharging means, the amount of the raw material or the fibrous material generated therefrom adheres to the electrode also increases. Therefore, as in the preferred embodiment of the present invention, the opening end of the bag is interposed between the raw material discharge means and the electrode, so that the raw material or the like can be prevented from adhering to the electrode. As a result, it is not necessary to perform maintenance in order to remove the raw material adhering to the electrode, and productivity can be improved.
In addition, leakage can be prevented from occurring through the raw material or the fibrous material, and the mechanism can be simplified, so that the manufacturing cost can be reduced. In particular, when the polymer material or the solvent mixed with the polymer material has conductivity, a remarkable leakage phenomenon occurs.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1
FIG. 1 is a side view, partly in section, showing a schematic configuration of a nanofiber manufacturing apparatus according to Embodiment 1 of the present invention.

  The manufacturing apparatus 1 includes a substantially cylindrical container 2 made of a conductor such as metal. The container 2 temporarily holds a liquid raw material F obtained by dispersing or dissolving a polymer material in a predetermined liquid. A large number of pores 2 a (see FIG. 7) for discharging the raw material F to the outside are formed on the peripheral wall of the container 2. The raw material F is supplied into the container 2 through the raw material supply pipe 27.

  The container 2 is a rotating container that is rotationally driven by an electric motor 5 connected to a rotating shaft 2b that coincides with the cylindrical axis. The raw material F is released from the pores 2a by the centrifugal force generated by the rotation of the container 2.

  Further, around the container 2, an annular electrode 3 shaped like a ring formed by joining both ends of the long plate in the longitudinal direction is opposed to the outer peripheral surface of the container 2 at a certain distance. It is arrange | positioned coaxially. The annular electrode 3 is connected to one terminal of the high voltage power supply 4. The other terminal of the high voltage power supply 4 is grounded. On the other hand, the container 2 is grounded. As a result, charges having opposite polarities are induced on the outer peripheral surface of the container 2 and the inner peripheral surface of the annular electrode 3, and an electric field is generated between the two.

The raw material F released from the pores 2a is given a charge at the openings of the pores 2a. The charged raw material F evaporates the solvent or dispersion medium while flying in the air, increases the internal coulomb force in the repulsion direction, and continuously causes electrostatic stretching phenomenon to be subdivided into fibers. Is done. In this way, the fibrous substance F1 is formed from the raw material F by the electrostatic stretching phenomenon.
Here, it is preferable that the pores 2 a are regularly formed on the peripheral wall of the container 2. For example, it is preferable that they are arranged at equal intervals in the axial direction of the container 2 and at equal pitches in the circumferential direction.

  In FIG. 1, the raw material F and the fibrous substance F1 are distinguished for convenience. However, in the actual production of nanofibers, the distinction between the raw material F and the fibrous substance F1 is ambiguous, and it is difficult to draw a clear line of the existing region. Accordingly, in the following description, only when there is a need for distinction, the raw material F and the fibrous substance F1 are described, and in other cases, the raw material F and the fibrous substance F1 are collectively referred to as the raw material F and the like. .

A front blower 6 is disposed at a position where the rotating shaft 2 b of the container 2 is further extended beyond the electric motor 5. The air flow 8 generated by the front blower 6 and the suction rear blower 20 described later is guided between the container 2 and the annular electrode 3 by the annular hood 10.
An annular heater 12 is disposed in the hood 10 at a position immediately downstream of the front blower 6. Thereby, the evaporation of the dispersion medium or solvent from the raw material F etc. can be accelerated | stimulated, and the fibrous substance F1 can be rapidly produced | generated from the raw material F. FIG. In addition, since the electrostatic stretching decrease is caused at an early stage, the fiber diameter of the generated fibrous substance F1 becomes smaller, and the fine fibrous substance F1 can be stably generated.

  By the air flow 8 generated by the front blower 6 or the like, the direction in which the raw material F travels is deflected in a direction (axial direction of the container 2) substantially perpendicular to the discharge direction (radial direction of the container 2). A collector 14 that collects the fibrous substance F1 is arranged in the direction in which the raw material F or the like is deflected (right direction in the illustrated example).

The collector 14 generates an air flow 8 in cooperation with a cylindrical bag storage 16 having an inner diameter that is substantially the same as the inner diameter of the annular electrode 3, a bag 18 for collecting the fibrous substance F 1, and the front blower 6. And a rear blower 20 for suction.
As shown in FIGS. 2 and 3, the bag storage unit 16 supports the bag 18 by arranging a net 22 made of an insulator at one end opening (net arrangement side opening) 16 b. The other end opening (opening side opening) 16a is open. The bag 18 is made of a mesh-like air-permeable fabric made of an insulator, and is shaped to fit inside the bag storage portion 16. An end (opening end) 18 b in the vicinity of the opening 18 a of the bag 18 protrudes from the opening 16 a of the bag storage portion 16 by a predetermined width. The opening end portion 18 b that is the protruding portion is inserted inside the annular electrode 3. Thereby, the annular electrode 3 is separated from the container 2 by the bag 18.

The rear blower 20 is connected to a small-diameter opening 24a of a megaphone-shaped annular airflow guiding section 24 whose diameter changes linearly in the axial direction. Further, in the annular airflow guiding portion 24, the large diameter side opening portion 24 b faces the net arrangement side opening portion 16 b of the bag storage unit 16.
A flow rate sensor 26 that measures the flow rate of the airflow 8 is disposed inside the annular airflow guiding unit 24. An output signal from the flow sensor 26 is input to the control unit 28. When the flow rate of the airflow 8 measured by the flow rate sensor 26 becomes equal to or less than a predetermined value, the control unit 28 assumes that a certain amount or more of the fibrous substance F has been collected in the bag 18, and The rotation and supply of the raw material F into the container 2 through the raw material supply pipe 27 are stopped.

Next, the operation of the nanofiber manufacturing apparatus having the above configuration will be described.
The raw material F is supplied into the container 2 through the raw material supply pipe 27. The container 2 is rotated at a predetermined speed by the rotation output of the electric motor 5. The raw material F supplied to the inside of the container 2 is released from the pores 2a by the centrifugal force generated by the rotation of the container 2. In addition, an electric field is generated between the grounded container 2 and the annular electrode 3 to which a high voltage is applied by the power source 4, and charges of opposite polarity are induced in the container 2 and the annular electrode 3, respectively. .

  The raw material F released from the pores 2 a by the centrifugal force is charged by the charge induced in the container 2. A force directed toward the annular electrode 3 acts on the charged raw material F by an electric field between the container 2 and the annular electrode 3.

  In this way, the raw material F is released radially from the pores 2a toward the annular electrode 3 by the centrifugal force and the electric field. The raw material F released from the pores 2a evaporates the dispersion medium or solvent while flying in the air, the volume of the raw material F decreases, and the charge density gradually increases. When the coulomb force in the repulsion direction inside the raw material F exceeds its surface tension, an electrostatic stretching phenomenon occurs. By repeating this phenomenon, the raw material F is subdivided into fibers, and the fibrous substance F1 (nanofiber) Is formed.

On the other hand, the raw material F released from the pores 2a or the fibrous substance F1 formed from the raw material F1 is moved in a direction substantially perpendicular to the discharge direction (the radial direction of the container 2) by the air flow 8 (the axis of the container 2). The fibrous material F1 is collected by the collector 14.
In the collector 14, the fibrous substance F <b> 1 is collected inside the bag 18 made of a net-like breathable fabric, and the fibrous substance F <b> 1 is collected by the bag 18. When the flow rate of the airflow 8 measured by the flow rate sensor 26 becomes a predetermined value or less, the control unit 28 stops the rotation of the container 2 by the electric motor 5 and the supply of the raw material F into the container 2 through the raw material supply pipe 27. The Thereafter, the bag 18 is replaced, and the above-described operation is repeated.

  As described above, in the first embodiment, the raw material F is released from the pores 2a formed on the peripheral wall of the container 2, and the fibrous substance F1 generated from the released raw material F has a net-like air permeability. Collected by a bag 18 made of fabric. Here, since the open end 18b of the bag 18 is inserted between the container 2 and the annular electrode 3, the raw material F discharged from the container 2 or the fibrous substance F1 generated therefrom is the annular electrode 3. Can be prevented. This eliminates the need for regular maintenance to remove the raw material F adhering to the annular electrode 3. Therefore, the frequency at which the apparatus is stopped can be reduced and productivity can be improved.

  In addition, since leakage through the fibrous substance F1 can be prevented, there is no need to provide a special mechanism for preventing leakage, and the mechanism is simplified. Further, there is no need to provide a mechanism for feeding a long strip-shaped collecting body in the longitudinal direction as in the prior art, and this further simplifies the mechanism.

Here, since the present invention can exhibit a unique effect of preventing leakage through the raw material F or the like, the properties of the polymer material constituting the raw material F, its dispersion medium or solvent This is particularly effective for the following three combinations. That is,
1) When the raw material F is composed of a non-conductive polymer material and a conductive dispersion medium or solvent,
2) When the raw material F is composed of a conductive polymer material and a non-conductive dispersion medium or solvent; and 3) When the raw material F is a conductive polymer material and a conductive dispersion medium. Or if it consists of a solvent,
There are three ways.

As an example of the raw material F in the first case, 10% cellulose (polymer material) is used as a solvent composed of an aqueous solution of ammonia and copper ions (copper: 5%, ammonia: 20%, water: 65%). A dissolved solution (copper ammonia cellulose dope) can be considered.
Examples of the raw material F in the second case include a polymer material composed of an ionic polymer material such as Nafion (registered trademark) and an auxiliary polymer such as PVDF (polyvinylidene fluoride), ethylene glycol, propylene glycol, and A solution dissolved in a solvent composed of at least one kind of glycerin is conceivable.
Examples of the polymer material having conductivity other than those described above include polyaniline, polyethylenedioxythiophene, polythiophene, and organic solvent-soluble polypyrrole.

  As described above, the present invention is particularly effective in the above three cases, but effects such as an improvement in productivity can be achieved even if it is applied in other cases.

  The container 2 is preferably 10 mm to 300 mm in outer diameter. This is because if the diameter of the container 2 exceeds 300 mm, it becomes difficult to appropriately concentrate the raw materials F and the like by the air flow. Moreover, if the diameter of the container 2 exceeds 300 mm, in order to rotate the container 2 stably, it is necessary to considerably increase the rigidity of the support structure that supports the container 2, and the apparatus becomes large. On the other hand, when the diameter of the container is smaller than 10 mm, it is necessary to increase the rotational speed in order to obtain a centrifugal force sufficient to release the raw material, and in this case, the vibration and vibration of the motor increase. This is because measures need to be taken. Considering the above points, the outer diameter of the container 2 is more preferably 20 to 100 mm.

  The diameter of the pore 2a is preferably 0.01 to 2 mm. The shape of the pores 2a is preferably circular, but may be a polygonal shape or a star shape. Further, a protrusion may be provided on the surface of the container 2, and the pore 2a may be provided at the tip. The rotation speed of the container 2 is, for example, in the range of several rpm or more and 10,000 rpm or less depending on the viscosity of the raw material F, the composition of the raw material F (type of polymer material), the type of solvent, the diameter of the pores 2a, and the like. Can be adjusted.

The annular electrode 3 may have an inner diameter of 200 to 1000 mm, for example.
Further, it is preferable to apply a voltage of 1 to 200 kV from the power source 4 to the annular electrode 3. More preferably, a high voltage of 10 kV or higher is applied. In particular, the electric field strength between the container 2 and the annular electrode 3 is important, and it is preferable to arrange the applied voltage and the annular electrode 3 so that the electric field strength is 1 kV / cm or more. Thereby, an equal and strong electric field can be generated between the container 2 and the annular electrode 3.

  The annular electrode 3 is not necessarily an annular electrode. For example, the shape seen from the axial direction may be a polygon. The annular electrode 3 only needs to be disposed so as to surround the container 2 at a predetermined distance from the peripheral surface of the container 2. For example, an annular metal wire is disposed so as to surround the container 2. It may be configured.

  The bag 18 is preferably made of a material such as polyethylene or polypropylene. The mesh is preferably 0.1 to 3 mm. However, the size of the mesh is not particularly limited, and the shape is not limited to the mesh. The bag 18 is a bag made of a fabric with high air permeability, and it is sufficient that the fibrous substance F1 generated can be collected in the bag.

In the first embodiment, while the container 2 is grounded, a high voltage is applied to the annular electrode 3 by the power source 4. However, the high voltage is applied to the container 2 by the power source 4 and the annular electrode 3 is connected to the annular electrode 3. It may be grounded. However, in this case, since a high voltage is applied to the rotating container 2, a special mechanism for insulating the container 2 from other members is required.
Alternatively, a voltage may be applied to both the container 2 and the annular electrode 3 by connecting the container 2 and the annular electrode 3 to two terminals of the power source 4, respectively. That is, it is only necessary that a potential difference is generated between the container 2 and the annular electrode 3, and an electric field is generated between the container 2 and the annular electrode 3 so that the raw material F flowing out of the pores 2a has a charge.

  Here, the polymer material included in the raw material F is polypropylene, polyethylene, polystyrene, polyethylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, poly-m-phenylene terephthalate, poly-p-phenylene isophthalate, polyfluoride. Vinylidene, vinylidene fluoride-hexafluoropropylene copolymer, polyvinyl chloride, vinylidene chloride-acrylate copolymer, polyacrylonitrile, acrylonitrile-methacrylate copolymer, polycarbonate, polyarylate, polyester carbonate, nylon, aramid, polycaprolactone, Examples of suitable ones include polylactic acid, polyglycolic acid, collagen, polyhydroxybutyric acid, polyvinyl acetate, and polypeptide. , At least one is used selected from these. However, the polymer materials that can be included in the raw material F are not limited to these, and even existing substances that have been newly recognized as being suitable as raw materials for nanofibers, or will be developed in the future Any substance that is suitable for use as a raw material for nanofibers can be suitably used.

  The dispersion medium or solvent for dispersing or dissolving the polymer material is methanol, ethanol, 1-propanol, 2-propanol, hexafluoroisopropanol, tetraethylene glycol, triethylene glycol, dibenzyl alcohol, 1,3- Dioxolane, 1,4-dioxane, methyl ethyl ketone, methyl isobutyl ketone, methyl-n-hexyl ketone, methyl-n-propyl ketone, diisopropyl ketone, diisobutyl ketone, acetone, hexafluoroacetone, phenol, formic acid, methyl formate, ethyl formate, Propyl formate, methyl benzoate, ethyl benzoate, propyl benzoate, methyl acetate, ethyl acetate, propyl acetate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, methyl chloride, ethyl chloride , Methylene chloride, chloroform, o-chlorotoluene, p-chlorotoluene, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, trichloroethane, dichloropropane, dibromoethane, dibromopropane, methyl bromide, ethyl bromide , Propyl bromide, acetic acid, benzene, toluene, hexane, cyclohexane, cyclohexanone, cyclopentane, o-xylene, p-xylene, m-xylene, acetonitrile, tetrahydrofuran, N, N-dimethylformamide, pyridine, water and the like are suitable. It can illustrate as a thing and at least 1 sort (s) chosen from these is used. However, the dispersion medium or solvent for dispersing or dissolving the polymer material is not limited to these, and even if it is an existing substance, the suitability of the polymer material as a dispersion medium or solvent in the electrospinning method is new. Or materials that will be developed in the future and can be suitably used as dispersion media or solvents can be suitably used.

The raw material F can also be mixed with an inorganic solid material. Examples of the inorganic solid material that can be mixed include oxides, carbides, nitrides, borides, silicides, fluorides, and sulfides. From the viewpoint of heat resistance, workability, etc., it is preferable to use an oxide. Examples of the oxide include Al ₂ O ₃ , SiO ₂ , TiO ₂ , Li ₂ O, Na ₂ O, MgO, CaO, SrO, BaO, B ₂ O ₃ , P ₂ O ₅ , SnO ₂ , ZrO ₂ , K _2. O, Cs ₂ O, ZnO, Sb ₂ O ₃ , As ₂ O ₃ , CeO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , MnO, Fe ₂ O ₃ , CoO, NiO, Y ₂ O ₃ , Lu ₂ O ₃ , Yb ₂ O ₃ , HfO ₂ , Nb ₂ O _{5 and the} like can be exemplified, and at least one selected from these can be used. However, the inorganic solid material mixed in the raw material F is not limited to these.

  Although the mixing ratio of the polymer material and the dispersion medium or solvent depends on the type of the polymer material, it is preferable that the mixing ratio is 60 to 98% by mass.

<< Embodiment 2 >>
Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is a modification of the first embodiment, and only the parts different from the first embodiment will be described below. For convenience of explanation, in each of the following embodiments, elements (the container 2, the annular electrode 3, etc.) other than the collector 14 and the control unit 28 of the manufacturing apparatus 1 are referred to as a nanofiber generation unit 30 (see FIG. 4). The rear fan 20, the annular airflow guiding unit 24 and the flow rate sensor 26 of the collector 14 are referred to as a suction unit 40.

As shown in FIGS. 4-6, in the nanofiber manufacturing apparatus of Embodiment 2, collector 14A is comprised so that the bag 18 can be replaced | exchanged by a revolver type.
That is, the collector 14 </ b> A includes a drum 32 that holds and rotates a plurality (four in the illustrated example) of the bag accommodating portions 16. The interior of the drum 32 is divided into a plurality (four in the illustrated example) of the same size space 32a in the circumferential direction by a partition plate 32d, and the bag accommodating portion 16 is held in each space 32a. The bag housing portion 16 is held in the space 32 a so that the respective central axes are parallel to the rotation shaft 32 b of the drum 32. Moreover, each bag accommodating part 16 has the opening side opening part 16a orient | assigned to the same side.

The drum 32 has a rotating shaft 32b supported on both sides, and a passive gear 32c is mounted on the rotating shaft 32b. Further, the drum rotating electric motor 46 is disposed so that the output rotating shaft 46a thereof is parallel to the rotating shaft 32b. An active gear 46 b is attached to the output rotating shaft 46 a, and a belt 48 is stretched between the active gear 46 b and the passive gear 32 c, and the drum 32 is rotationally driven by the drum rotating motor 46. The drum rotating motor 46 is controlled by the control unit 28.
And the nanofiber production | generation part 30 is distribute | arranged to the side which the opening side opening part 16a of the bag accommodating part 16 faces in the drum 32, and the suction part 40 is distribute | arranged to the other side.

  In the second embodiment, the control unit 28 controls the drum 32 to rotate by a predetermined angle after stopping the nanofiber generation operation when the detection value of the flow sensor 26 becomes a predetermined value or less. I do. Here, the angle at which the drum 32 is rotated is adjusted according to the number of the bag accommodating portions 16 held on the drum 32. For example, if the number of bag accommodating portions 16 is “4”, the drum 32 is rotated 90 ° (= 360 ° ÷ 4) per time. If the number of bag accommodating portions 16 is “6”, the drum 32 is rotated 60 ° (= 360 ° ÷ 6) per time.

  In addition, the apparatus according to the present embodiment includes a mechanism 50 (generation unit advance / retreat mechanism) that advances and retracts the nanofiber generation unit 30. The generation unit advancing / retreating mechanism 50 stops the nanofiber generation operation and then rotates the drum 32 before rotating the drum 32, as shown in FIG. 7, the opening end portion 18b of the bag 18 inserted inside the annular electrode 3. In order to remove the nanofibers, the nanofiber generating unit 30 is moved backward. Further, the generation unit advancing / retreating mechanism 50 moves the nanofiber generation unit 30 forward so that the opening end 18b of the next bag 18 is inserted inside the annular electrode 3 after the drum 32 is rotated by a predetermined angle. Operate. The operation of the generation unit advance / retreat mechanism 50 is controlled by the control unit 28.

8 and 9 show an example of the generation unit advance / retreat mechanism 50. FIG. The generation unit advancing / retreating mechanism 50 in the illustrated example includes a generation unit support unit 34 that supports the nanofiber generation unit 30, a linear motion mechanism 42, and a linear motion mechanism support unit 44 that supports the linear motion mechanism 42.
The linear movement mechanism 42 includes an insertion position (see FIG. 1) where the opening end 18b of the bag 18 is inserted inside the annular electrode 3, and a removal where the opening end 18b of the bag 18 is removed from the inside of the annular electrode 3. This is a mechanism that linearly moves the generation unit support 34 so that the nanofiber generation unit 30 moves forward and backward with respect to the leaving position (see FIG. 7).

As described above, by providing the collector 14A with the bag changing mechanism for changing the bag 18 into the revolver type, the drum 32 is rotated each time a predetermined amount of the fibrous substance F1 is collected by the bag 18, Collection of the fibrous material F1 can be performed using a new bag 18.
Therefore, the stop time of the generation operation by the nanofiber generation unit 30 can be minimized. This further increases productivity.

  As shown in FIG. 10, when the opening end portion of the bag 18 does not protrude from the opening side opening portion 16a of the bag storage portion 16, the generation unit advancing / retreating mechanism 50 is omitted, and the revolver type bag The bag 18 can be exchanged by the exchange mechanism. This shortens the time required for replacing the bag 18 and simplifies the mechanism. However, in this case, the effect of reducing the frequency of maintenance for removing the raw material F and the like adhering to the annular electrode 3 cannot be achieved.

<< Embodiment 3 >>
Next, a third embodiment of the present invention will be described with reference to FIGS. The third embodiment is a modification of the first embodiment, and only the parts different from the first embodiment will be described below.

As shown in FIGS. 11 to 13, in the nanofiber manufacturing apparatus according to the third embodiment, the collector 14 </ b> B is configured to be exchangeable by sliding the bag 18 sideways.
In other words, the collector 14 </ b> B includes a slide-type bag exchange mechanism 60. The bag replacement mechanism 60 includes a plurality (two in the illustrated example) of rectangular cylinders 46 each holding a plurality of bag storage portions 16 and a cylinder linear motion mechanism 48.

  The rectangular cylindrical body 46 is attached to the cylindrical linear motion mechanism 48 so that the length direction is parallel to the direction perpendicular to the moving direction of the cylindrical linear motion mechanism 48. On the other hand, although not clearly shown in the drawing, the bag accommodating portions 16 are inserted into the respective rectangular cylinders 46 so that the respective opening-side openings 16a face the same side. Thereby, as for the bag 18 accommodated in each of the bag accommodating parts 16, all the opening parts 18a have faced the same side.

And the nanofiber production | generation part 30 is distribute | arranged to the side which the bag 18 of the square cylinder 46 opens, and the suction part 40 is distribute | arranged to the other side.
In the third embodiment, a generation unit advance / retreat mechanism 50 similar to that in the second embodiment is provided. And the control part 28 stops the production | generation operation | movement of the nanofiber by the nanofiber production | generation part 30, when the detected value of the flow sensor 26 becomes below a predetermined value. Thereafter, the generation unit advancing / retreating mechanism 50 is controlled to retract the nanofiber generation unit 30 in order to remove the opening end 18b of the bag 18 inserted inside the annular electrode 3. Then, in order to collect the fibrous material using the next bag, the respective rectangular cylinders 46 are slid in the lateral direction.

Next, the control unit 28 controls the nanofiber generation unit 30 to advance in order to insert the opening end 18 b of the next bag 18 into the inside of the annular electrode 3.
As described above, the same effect can be obtained by the same control as that of the second embodiment even by the sliding bag exchange mechanism.

<< Embodiment 4 >>
Next, a fourth embodiment of the present invention will be described with reference to FIGS. The fourth embodiment is a modification of the first embodiment, and only the parts different from the first embodiment will be described below.

In the fourth embodiment, in the nanofiber generator, the container 2A has a box shape, and the pores from which the raw material F is released are open at the tip of the nozzle 2c provided on the lower wall surface of the container.
In the fourth embodiment, instead of the annular electrode 3, a plate electrode 3A is disposed so as to face the lower surface of the container 2A at a predetermined distance from the lower surface of the container 2A. The plate electrode 3 </ b> A is connected to one terminal of the high voltage power supply 4. The other terminal of the high voltage power supply 4 is grounded. The container 2A is grounded. As a result, an electric field is generated between the container 2A and the plate-like electrode 3A, and charges having opposite polarities are induced in the container 2A and the plate-like electrode 3A, respectively.

The raw material F is supplied to the inside of the container 2A at a predetermined pressure via the raw material supply pipe 27A. With this supply pressure, the raw material F is discharged from the tip of the nozzle 2c toward the plate electrode 3A. .
A blower 6A is disposed on the side of the space between the container 2A and the plate electrode 3A so as to blow air toward the space between the container 2A and the plate electrode 3A. The raw material F discharged from the tip of the nozzle 2c toward the plate electrode 3A is deflected in a direction perpendicular to the discharge direction by the air flow generated by the blower 6A.

  On the other hand, with respect to the space between the container 2A and the plate-like electrode 3A, a rectangular bag housing portion 16A is arranged in a direction opposite to the direction in which the blower 6 is arranged. Inside the bag storage portion 16A, a square bag 18A is stored with its opening facing the space. As shown in FIG. 16, the bag 18 </ b> A has one side of the square opening extending, and the extending portion covers the plate electrode 3 </ b> A between the container 2 </ b> A and the plate electrode 3 </ b> A. Has been. In addition, as shown in FIG. 17, bag 18A can also be made into the shape which abbreviate | omitted the extension part.

As described above, the present invention is not limited to the case of discharging a raw material by a centrifugal force due to its rotation using a substantially cylindrical container, and the material is discharged from a rectangular box-shaped container by its supply pressure. It is also possible.
Moreover, as shown in FIG. 15, the raw material discharge | release means of a nanofiber production | generation part can also be made to spray and discharge | release. In this example, the raw material discharge means is composed of a two-fluid nozzle 2B, and the high-pressure gas supplied from the gas source 52 is supplied from the gas source 52 to the raw material supplied by the pump 38 at a predetermined pressure and discharged from the tip of the nozzle 2B. Is atomized.

  The fibrous substance F1 produced | generated from the atomized raw material F is collected by the square bag 18B distribute | arranged inside the square bag accommodating part 16A arrange | positioned in the direction of injection of a high pressure gas. Thus, when the raw material F is injected by the two-fluid nozzle 2B, it can be collected simply by arranging the bag 18B in the injection direction, and the opening end of the bag 18B is connected to the two-fluid nozzle 2B, the electrode 3, and the like. There is no need to interpose them.

  Further, as shown in FIG. 16, even in an apparatus having a configuration in which the annular electrode 3B is arranged at a position upstream of the discharge hole 2a of the container 2C (upstream side in the airflow 8b), the raw material F or the like is provided on the annular electrode 3B. There is no risk of adhesion. Therefore, also in this case, there is no need to sandwich the open end portion 18b of the bag 18 between the container 2B and the annular electrode 3.

In each of the above embodiments, the electrodes (3, 3A, 3B) are arranged in a direction substantially orthogonal to the air flow 8b from the raw material discharge means (2, 2A, 2B, 2C). However, the present invention is not limited to this, and an electrode is arranged on the downstream side of the air flow 8b, for example, between the bag storage portion 16 of the collector 14 and the rear blower 20, and a potential difference is generated between the raw material discharge means and the electrode. You may comprise so that it may have.
In each embodiment, the bag is made of a mesh-like air-permeable fabric. However, the present invention is not limited to this, and the fabric is not limited to the mesh shape and may be any air-permeable material.

  According to the nanofiber manufacturing apparatus and manufacturing method of the present invention, when manufacturing nanofibers using the electrospinning method, it is possible to manufacture high-quality nanofibers with high productivity.

It is the side view which made the cross section a part which shows schematic structure of the nanofiber manufacturing apparatus which concerns on Embodiment 1 of this invention. It is a perspective view which shows the detail of the collector of the apparatus of FIG. It is the perspective view which looked at the same collector from another angle. It is the perspective view which simplified a part of nanofiber manufacturing apparatus concerning Embodiment 2 of the present invention. It is a side view of the same apparatus. It is a front view which shows the detail of the collector of the apparatus. FIG. 2 is a side view similar to FIG. 1 that is referred to for explaining the operation of the apparatus. It is a side view of the production | generation part advance / retreat mechanism of the same apparatus. It is a side view similar to FIG. It is a perspective view which shows the other form of a bag. It is the perspective view which simplified a part of nanofiber manufacturing apparatus concerning Embodiment 3 of the present invention. It is a top view of the manufacturing apparatus. FIG. 13 is a plan view similar to FIG. 12, showing another operation state of the manufacturing apparatus. It is the side view which made a part of nanofiber manufacturing device concerning Embodiment 4 of the present invention a section. It is the side view which made a part of modification of the manufacturing apparatus the section. It is the side view which made a part of other modification of the manufacturing apparatus of FIG. 14 the cross section. It is a perspective view which shows an example of the bag used for the apparatus of FIG. It is a perspective view which shows another example of the bag.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nanofiber manufacturing apparatus 2 Container 2a Pore 3 Ring electrode 4 High voltage power supply 14 Collector 16 Bag accommodating part F Raw material F1 Fibrous material

Claims (12)

A nanofiber manufacturing method in which a liquid raw material containing a polymer material is charged and discharged into the air, and a fibrous substance is generated from the raw material by an electrostatic stretching phenomenon,
The nanofiber manufacturing method which collects the produced | generated fibrous substance with the bag which consists of a fabric which at least one part has air permeability. A nanofiber manufacturing apparatus that charges a liquid raw material containing a polymer material and discharges it into the air, and generates a fibrous substance from the raw material by an electrostatic stretching phenomenon,
A raw material release means for discharging the raw material into the air, at least a part of which is made of a conductor;
An electrode disposed at a predetermined distance from the raw material discharge means;
A potential difference applying means for providing a potential difference between the raw material discharge means and the electrode so as to generate an electric field between the raw material discharge means and the electrode;
A collecting means for collecting a fibrous material generated from the raw material by an electrostatic stretching phenomenon, and
The nanofiber manufacturing apparatus, wherein the collecting means includes a bag made of a fabric having at least a part of air permeability. The raw material is released from the raw material release means toward the electrode;
The nanofiber manufacturing apparatus according to claim 2, further comprising a deflecting unit configured to deflect the discharged raw material or the fibrous material generated therefrom in a direction different from a discharge direction of the raw material.   The nanofiber manufacturing apparatus according to claim 2 or 3, wherein an opening end portion of the bag is interposed between the raw material discharge means and the electrode.   The nanofiber manufacturing apparatus according to any one of claims 2 to 4, further comprising a revolver type bag exchanging means.   The nanofiber manufacturing apparatus according to any one of claims 2 to 4, further comprising a sliding bag exchange means. The raw material releasing means is
The nanofiber manufacturing apparatus according to any one of claims 2 to 6, comprising a substantially cylindrical rotating container in which pores for discharging the raw material are formed in a peripheral wall, and the raw material is introduced into the inside. The raw material releasing means is
7. A structure comprising a container having at least one flat surface, pores for discharging the raw material formed in a wall portion of the surface, and the raw material being introduced therein at a predetermined pressure. The nanofiber manufacturing apparatus according to any one of the above.   The said raw material discharge | release means is comprised from 2 fluid nozzles, The said raw material discharge | released from the at least 1 hole of the said nozzle is atomized with the gas injected from the at least 1 other hole of the said nozzle, and discharge | releases. The nanofiber manufacturing apparatus in any one of 2-8.   The nanofiber manufacturing apparatus according to any one of claims 2 to 9, wherein at least one of the polymer material and the liquid component constituting the raw material has conductivity.   The nanofiber manufacturing apparatus according to any one of claims 3 to 10, wherein the deflecting unit includes an airflow generating unit that generates an airflow by at least one of air blowing and suction.   The nanofiber manufacturing apparatus according to claim 11, further comprising a flow rate measuring unit that measures a flow rate of the airflow generated by the airflow generation unit, and a control unit that controls the bag replacement unit based on a measurement result of the flow rate measuring unit.

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