JP4312090B2 - Method for manufacturing fiber assembly and apparatus for manufacturing fiber assembly by electrostatic spinning - Google Patents

Description

  The present invention relates to a fiber assembly manufacturing method and a fiber assembly manufacturing apparatus by an electrospinning method, and in particular, manufactures a low-density cotton-like fiber assembly in which fibers are not bonded to each other or bonded extremely weakly. The present invention relates to a fiber assembly manufacturing method and a fiber assembly manufacturing apparatus by an electrostatic spinning method.

  Conventionally, in the production of polymer fiber aggregates by electrostatic spinning, when an electric field is simultaneously applied while extruding a polymer solution as a raw material through fine holes, the solvent in the polymer solution volatilizes and solidifies to polymer fibers. And is collected in a collection device or the like located at a certain distance. This polymer fiber aggregate is a form in which fibers having a diameter of several nm to several thousand nm are accumulated in a three-dimensional network structure, and has a very large surface area per unit volume. Therefore, it has a very large porosity and specific surface area as compared with polymer fiber aggregates produced by other production methods.

Such a fiber assembly manufacturing method and apparatus includes a liquid reservoir (applied to a high voltage or grounded) having a nozzle part capable of supplying a liquid polymer to the spinning space, and a counter electrode for integration (flat plate, roll). ). The fibers spun by the electric field from the nozzle portion are collected on the collecting counter electrode, and then the collected fiber aggregate is collected by a scraping device or the like (for example, see Patent Document 1).
US Pat. No. 2,048,651 (page 2-3, FIG. 2)

  However, in this Patent Document 1, since fibers are directly accumulated on the counter electrode for accumulation by the electric field force, a paper-like fiber aggregate is formed by electrostatic force with the counter electrode for accumulation due to the charged fibers, resulting in low density cotton. There was a problem that it could not be recovered as a fiber aggregate. Also, when a scraping device is provided on the electrode, the fiber aggregate after scraping is not bulky and cannot be used as a bulky fiber aggregate such as a heat insulating material. Furthermore, the accumulated fibers may be firmly bonded to each other.

  The present invention has been made in order to solve such a conventional problem, and it is possible to produce a low-density cotton-like fiber assembly in which fibers are not bonded to each other or bonded extremely weakly. It is an object of the present invention to provide a method for manufacturing a fiber assembly by an electrospinning method and a fiber assembly manufacturing apparatus.

A method for producing a fiber assembly by an electrospinning method according to the present invention includes a step of supplying a polymer solution to be spun into a spinning space, a step of supplying a first air stream in a direction of supplying the polymer solution, While irradiating the formed fibers with ions having a polarity opposite to the charge of the fibers , and supplying a second air stream in a direction intersecting with the direction of supplying the polymer solution and collecting the spun fibers, Recovering the fibers.

  In this method, the fibers formed by supplying to the spinning space are irradiated with ions of the opposite polarity to the fibers, so that the charging of the fibers is neutralized, the flying force due to electrostatic force is lost, and the fibers are dropped by gravity, A low-density and cotton-like fiber aggregate is obtained. At this time, by supplying the first air stream, it is possible to prevent the electrically neutralized fibers from adhering to the portion where the polymer solution is supplied. Further, by supplying the second air stream, it is possible to prevent the electrically neutralized fibers from adhering to the counter electrode for electrically attracting the fibers. Therefore, stable production of the fiber assembly becomes possible.

  Here, it is preferable that the flow velocity of the first air stream is faster than the flow velocity of the second air stream. Thereby, since the electrically neutralized fiber can be effectively prevented from adhering to the portion supplying the polymer solution, the fiber assembly can be manufactured more stably.

  The method for producing a fiber assembly by the electrospinning method according to the present invention includes a step of supplying polymer solutions of opposite polarities to the spinning space from the first and second positions facing each other, and a polymer solution from the first position. Supplying a first air stream in the direction of supplying the polymer solution; supplying a second air stream in a direction of supplying the polymer solution from the second position; and the first position and the second position. Collecting the fibers while supplying a third airflow in a direction intersecting the opposing direction and collecting the spun fibers.

  In this method, by supplying polymer solutions of opposite polarities to the spinning space from opposite positions, the fibers charged in opposite polarities come into contact with each other and approach each other to neutralize the charge, thereby increasing the flying force due to electrostatic force. Loses and falls due to gravity, a low-density, cotton-like fiber assembly is obtained. At this time, by supplying the first and second air currents, it is possible to prevent the electrically neutralized fibers from adhering to the portions supplying the polymer solution at the first and second positions, respectively. it can. Further, by supplying the third air flow, the neutralized fibers supplied from the portions supplying the polymer solution at the first and second positions are respectively supplied with the polymer solutions at the second and first positions facing each other. It can prevent adhering to the supply part. Therefore, it becomes possible to manufacture a fiber assembly stably.

  Here, it is preferable that the flow velocity of the first and second airflows is faster than the flow velocity of the third airflow. As a result, it is possible to effectively prevent the electrically neutralized fibers from adhering to the portions that supply the polymer solution at the first and second positions, so that the fiber assembly can be manufactured more stably. Can do.

  Moreover, it is preferable that the flow velocity of the first air flow and the flow velocity of the second air flow are substantially equal. Thereby, since fibers can be collected stably without disturbing the airflow in the spinning space, the fiber assembly can be manufactured more stably.

  The fiber assembly manufacturing apparatus according to the present invention is opposed to a polymer supply unit capable of supplying a polymer solution to a spinning space, charge applying means capable of applying a charge to the polymer solution, and the polymer supply unit. A counter electrode capable of electrically attracting the fibers formed by supplying the solution; and means capable of irradiating the fibers flying between the polymer supply unit and the counter electrode with ions having a polarity opposite to the charge of the fibers; A fiber recovery device capable of recovering the spun fiber, a first blower device capable of supplying a first airflow in a direction from the polymer supply unit to the counter electrode, and a fiber intersecting with the direction from the polymer supply unit to the counter electrode And a second air blower capable of supplying a second airflow in a direction toward the recovery device.

  By irradiating the fibers formed by supplying the polymer solution to the spinning space with ions of the opposite polarity to the fibers, the charging of the fibers is neutralized, the flying force due to electrostatic force is lost, and the fibers are dropped by gravity. A low-density and cotton-like fiber aggregate is obtained. At this time, it is possible to prevent the electrically neutralized fibers from adhering to the polymer supply unit by supplying the first airflow with the first blower. Moreover, it can prevent that the electrically neutralized fiber adheres to a counter electrode by supplying a 2nd airflow with a 2nd air blower. Therefore, it becomes possible to manufacture a fiber assembly stably.

  Here, the ion irradiation means may be an ionizing radiation source. As a result, it is possible to generate and irradiate ions independently from the formation of a potential difference between the polymer supply unit and the counter electrode by the ionizing radiation source. The fiber assembly can be stably produced.

  Moreover, it is preferable that the flow velocity of the 1st airflow which a 1st air blower supplies is faster than the flow velocity of a 2nd airflow. Thereby, since the electrically neutralized fiber can be effectively prevented from adhering to the polymer supply unit, the fiber assembly can be manufactured more stably.

  The fiber assembly manufacturing apparatus according to the present invention includes a first polymer supply unit capable of supplying a polymer solution to the spinning space, and a first polymer supply unit capable of supplying a charge to the polymer solution supplied from the first polymer supply unit. A second polymer supply unit that is opposite to the first polymer supply unit and can supply the polymer solution to the spinning space; and a polymer solution supplied from the second polymer supply unit. A second charge imparting means capable of applying a charge having a polarity opposite to that of the polymer solution supplied from the first polymer supply section; a fiber recovery apparatus capable of recovering the spun fiber; and a second charge from the first polymer supply section. The first air blower capable of supplying the first air stream in the direction toward the polymer supply unit, and the second air stream in the direction from the second polymer supply unit toward the first polymer supply unit. A third air blower capable of supplying a third airflow in a direction crossing the direction in which the second air blower, the first polymer supply unit and the second polymer supply unit face each other and toward the fiber recovery device; It is characterized by providing.

  In this device, by supplying polymer solutions of opposite polarities to the spinning space from opposite positions, the fibers charged in opposite polarities come into contact with each other and approach each other to neutralize the charge, and the flying force by electrostatic force And fall by gravity to obtain a low-density, cotton-like fiber assembly. At this time, by supplying the first and second air currents, it is possible to prevent the electrically neutralized fibers from adhering to the first and second polymer supply portions. Further, by supplying the third air flow, the neutralized fibers supplied from the portions supplying the polymer solution at the first and second positions are respectively supplied with the polymer solutions at the second and first positions facing each other. It can prevent adhering to the supply part. Therefore, it becomes possible to manufacture a fiber assembly stably.

  Furthermore, since the amount of fibers can be increased by using the first and second polymer supply units, the productivity of the fiber assembly is excellent. Moreover, a fiber assembly in which different kinds of fibers are mixed, such as different fiber diameters and different fiber component compositions, can be produced.

  Here, it is preferable that the flow velocity of the first and second airflows is faster than the flow velocity of the third airflow. Thereby, since the electrically neutralized fiber can be effectively prevented from adhering to the first and second polymer supply sections, the fiber assembly can be manufactured more stably.

  Moreover, it is preferable that the flow velocity of the first air flow and the flow velocity of the second air flow are substantially equal. Thereby, since fibers can be collected stably without disturbing the airflow in the spinning space, the fiber assembly can be manufactured more stably.

  According to the present invention, it is possible to stably produce a low-density and cotton-like fiber assembly in which fibers are not bonded to each other or bonded extremely weakly.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a fiber assembly manufacturing method and a fiber assembly manufacturing apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol shall be used for the same element and the overlapping description is abbreviate | omitted. Further, the dimensional ratios in the drawings do not necessarily match those described.

[First Embodiment]
FIG. 1 is a schematic view showing a fiber assembly manufacturing apparatus according to the first embodiment.

  As shown in FIG. 1, the fiber assembly manufacturing apparatus 1 includes a spinning chamber 3 for spinning fibers. The spinning chamber 3 has a main chamber 31 and a sub chamber 32. The main chamber 31 is composed of a substantially rectangular parallelepiped casing, and includes a bottom wall portion 31d and an upper wall portion 31b that face each other in the vertical direction, and a right wall portion 31c and a left wall portion 31a that face each other in the horizontal direction. It is out. The sub chamber 32 is configured by a substantially rectangular parallelepiped casing smaller than the main chamber 31, and is continuously provided on the left side wall portion 31 a of the main chamber 31. A communication hole 40 is provided in a portion of the left side wall portion 31a of the main chamber 31 where the sub chamber 32 is provided, and the main chamber 31 and the sub chamber 32 communicate with each other.

  In the sub chamber 32, a spinning nozzle 2 (polymer supply section) for supplying a polymer solution as a raw material of the fiber to the spinning space in the main chamber 31 is provided. The spinning nozzle 2 is connected to a polymer feeder 6 that supplies a polymer solution and a first high-voltage power source 7 (charge imparting means) that can apply a charge to the polymer solution.

  A counter electrode 5 is provided in the main chamber 31 in the vicinity of the right side wall 31c so as to face the spinning nozzle 2 in the horizontal direction. A second high voltage power supply 8 is connected to the counter electrode 5. The counter electrode 5 electrically attracts the fibers formed by supplying the polymer solution, and irradiates the fibers flying in the spinning space with ions 5a having a polarity opposite to the charge of the fibers.

  A collection member 4 (fiber collection device) such as a net or a conveyor is provided on the bottom wall 31d in the main chamber 31. The collected fiber 4 collects the spun fibers.

  The fiber assembly manufacturing apparatus 1 also includes a temperature / humidity control device 30 that sends an air flow into the spinning chamber 3 to control temperature and humidity. A first air duct 301 is provided between the temperature / humidity control device 30 and the sub chamber 32, and a second air duct is provided between the temperature / humidity control device 30 and the upper wall portion 31 b of the main chamber 31. 302 is provided.

  When airflow is supplied from the temperature / humidity control device 30 into the sub chamber 32 through the first blower pipe 301, the airflow is supplied into the main chamber 31 through the communication hole 40 toward the counter electrode 5. Thus, the temperature / humidity control device 30 and the first blower tube 301 constitute a first blower. Further, when an air flow is supplied from the temperature / humidity control device 30 into the main chamber 31 through the second blower pipe 302, the air flow is supplied vertically downward from the upper wall portion 31b toward the bottom wall portion 31d in the main chamber 31. The Thus, the temperature / humidity control device 30 and the second blower tube 302 constitute a second blower.

  Further, in the fiber assembly manufacturing apparatus 1 according to the present embodiment, the suction device 9 is connected to the bottom wall portion 31 d of the main chamber 31. When the suction machine 9 is operated, an air flow toward the collecting member 4 is generated in the main chamber 31. Therefore, when operating the suction device 9, the temperature / humidity control device 30, the second blower pipe 302, and the suction device 9 constitute a second blower device.

  In the present embodiment, the temperature / humidity control device 30 is shared by the first blower and the second blower, but a blower for blowing air between the first blower and the second blower, etc. These devices may be provided separately.

  Here, as the spinning nozzle 2, a metal / non-metallic pipe having an inner diameter of about 0.01 to 5 mm can be used. Further, as shown in FIG. 2, an edge electrode having a saw-tooth gear 20 rotating in a polymer solution container 22 containing a polymer solution 21 as an electrode, with the tip 20 a of the saw-tooth gear 20 facing the counter electrode 5 as an electrode. Can be used. Similarly, as shown in FIG. 3, the wire 20 b is rotated in the polymer solution container 22 by a roller 23, and the conveyor-like wire 20 b on which the polymer solution is placed can be used as an electrode. In FIG. 3, the counter electrode (not shown) is arranged perpendicular to the paper surface. Further, various conventional electrospinning electrodes can be used.

  As the counter electrode 5, a corona discharge needle (which may be applied with high voltage or ground), a corona discharge wire (which may be applied with high voltage or ground), an AC discharge element, or the like can be used. Further, a creeping discharge element as shown in FIG. 4 can be used as the AC discharge element. That is, in FIG. 4, the creeping discharge element 25 is provided with a discharge electrode 27 and an induction electrode 28 with a dielectric substrate 26 (for example, an alumina film) interposed therebetween, and an alternating high voltage is applied between these electrodes, thereby Creeping discharge is generated at the electrode 27 portion, and positive and negative ions can be generated.

  Polymers that can be used in the fiber assembly production apparatus 1 according to the present embodiment include polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile (PAN), and polyacrylonitrile-methacrylate copolymer. , Polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride-acrylate copolymer, polyethylene, polypropylene, nylon 12, nylon-4,6 and other nylons, aramid, polybenzimidazole, polyvinyl alcohol, cellulose, cellulose acetate, Cellulose acetate butyrate, polyvinyl pyrrolidone-vinyl acetate, poly (bis- (2- (2-methoxy-ethoxyethoxy)) phosphazene) (poly (bis- (2- (2-methoxy-ethoxyethoxy)) phosphazene); MEEP) , Polypropylene oxide, polyethylene Polyimide (PEI), poly (ethylenesuccinate), polyaniline, polyethylene sulfide, polyoxymethylene-oligo-oxyethylene (poly (oxymethylene-oligo-oxyethylene)), SBS copolymer, polyhydroxybutyric acid, poly Production of vinyl acetate, polyethylene terephthalate, polyethylene oxide, collagen, polylactic acid, polyglycolic acid, poly D, L-lactic acid-glycolic acid copolymer, polyarylate, polypropylene fumarate (poly (propylene fumalates)), polycaprolactone, etc. Various polymers that can be melted or dissolved in an appropriate solvent such as biodegradable polymers, polypeptides, biopolymers such as proteins, pitch systems such as coal tar pitch, petroleum pitch, etc. are applicable, and copolymers and mixtures thereof. Etc. can also be used. A spinnable sol solution obtained by hydrolyzing a metal alkoxide can also be used.

  Furthermore, an emulsion such as a synthetic resin or an organic or inorganic powder can be mixed with the polymer solution. Examples of the polymer solvent include (a) highly volatile acetone, chloroform, ethanol, isopropanol, methanol, toluene, tetrahydrofuran, water, benzene, benzyl alcohol, 1,4-dioxane, propanol, carbon tetrachloride, cyclohexane, (B) N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N, N-dimethylacetamide (DMAc) with relatively low volatility, such as cyclohexanone, methylene chloride, phenol, pyridine, trichloroethane, and acetic acid 1-methyl-2-pyrrolidone (NMP), ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), acetonitrile (AN), N-methylmorpholine-N-oxide, butylene carbonate (BC), 1,4-butyrolactone (BL), diethyl carbonate (DEC), diethyl ether (DEE), 1,2-dimethoxyethane (DME), 1,3-dimethyl-2-imidazolidinone (DMI), 1,3-dioxolane (DOL), ethyl methyl carbonate (EMC ), Methyl formate (MF), 3-methyloxazolidine-2-one (MO), methyl propionate (MP), 2-methyltetrahydrofuran (MeTHF), sulfolane (SL) and the like.

  Preferably, if the solvent for dissolving the polymer is a highly volatile solvent or a mixed solvent obtained by mixing a highly volatile solvent and a solvent having a relatively low volatility, the volatility of the solvent may be increased. Since the viscosity of the solution can be reduced, productivity can be improved by increasing the discharge amount from each nozzle.

  Then, the manufacturing method of the fiber assembly by the electrostatic spinning method in the fiber assembly manufacturing apparatus 1 which concerns on this embodiment is demonstrated. First, a polymer solution that is a raw material of the fiber to be spun is supplied from the polymer supply machine 6 to the spinning nozzle 2. Next, the polymer solution is discharged from the tip of the spinning nozzle 2 while a high voltage is applied between the spinning nozzle 2 and the counter electrode 5. Then, the solvent of the charged liquid polymer volatilizes and solidifies to become a fiber and proceeds toward the counter electrode 5. At this time, ions 5 a are irradiated toward the fiber from the counter electrode 5 disposed facing the spinning nozzle 2. The charge of the fiber is neutralized by the ions, the flying force due to the electrostatic force is lost, the fiber is dropped according to gravity, and the fiber is collected by the collecting member 4. Accordingly, a low-density and cotton-like fiber assembly can be obtained.

  At this time, the electrically neutralized fiber is supplied to the spinning nozzle 2 by supplying the first air flow 30a from the sub chamber 32 into the main chamber 31 through the first air duct 301 from the temperature / humidity controller 30. Adhesion can be prevented. Further, the second air flow 30b is supplied from the temperature / humidity control device 30 into the main chamber 31 through the second air duct 302, thereby preventing electrically neutralized fibers from adhering to the counter electrode 5. can do. Therefore, a fiber assembly can be manufactured stably.

  Here, it is preferable that the flow velocity of the first air flow 30a supplied by the first blower is faster than the flow velocity of the second air flow 30b supplied by the second blower. Thereby, since the electrically neutralized fiber can be effectively prevented from adhering to the spinning nozzle 2, the fiber assembly can be manufactured more stably.

  The flow rate of the first air flow 30a is 5 to 100 cm / sec. Is preferably 15 to 60 cm / sec. Is more preferable. 5 cm / sec. If the ratio is less than 100 cm / sec, the fibers tend to adhere to the spinning nozzle 2. This is because the fiber tends to adhere to the counter electrode 5 when the value exceeds.

  Furthermore, the flow velocity of the second air flow 30b is 3 to 100 cm / sec. Is preferable, and 10 to 40 cm / sec. Is more preferable. 3 cm / sec. If the ratio is less than 100 cm / sec, the fibers tend to adhere to the counter electrode 5. In this case, the fibers are strongly beaten against the collecting member 4 and the airflow suction force needs to be increased. Therefore, the fibers are not bonded to each other, or are low-density and cotton-like (bulky) fiber aggregates. This is because it tends to be difficult to manufacture.

  Furthermore, the airflow (preferably the first airflow 30a, which has the slower flow velocity of the difference (fd = | f1-f2 |) between the flow velocity (referred to as f1) of the first airflow 30a and the flow velocity (referred to as f2) of the second airflow 30b. The percentage of the second air flow 30b) with respect to the flow rate is preferably 10 to 200%, more preferably 50 to 100%. Even if it is less than 10% or more than 200%, the balance of the air flow is easily lost, and the fibers easily adhere to various places including the spinning nozzle 2 and the counter electrode 5, and the fiber aggregate is formed. This is because it tends to be difficult to produce stably.

  In addition, generation | occurrence | production and irradiation of the ion 5a can be performed continuously or discontinuously. Further, an electric field may be generated between the spinning nozzle 2 and the counter electrode 5, and a high voltage may be applied to only one of them and the other may be grounded. Further, the spinning nozzle 2 may be heated or not heated.

  As shown in FIG. 5, instead of the counter electrode 5 of FIG. 1, an ionizing radiation source 10 that can irradiate ionizing radiation 10a and a net-like counter electrode 5 that can electrically attract fibers may be used. In this case, the third high voltage power supply 11 is connected to the counter electrode 5.

  In this configuration, a predetermined voltage is applied to the spinning nozzle 2 and / or the counter electrode 5 by the first high voltage power source 7 and / or the third high voltage power source 11, so that the spinning nozzle 2 and the counter electrode 5 are interposed. A potential difference is generated, and the fiber is electrically attracted while being pushed by the first air flow 30 a and flies toward the counter electrode 5. The flying fiber is irradiated with ionizing radiation 10a, ionizes the gas, and acts as an ion source. As a result, the charging of the fibers is neutralized, the flying force due to the electrostatic force is lost, the fibers fall according to gravity while being pushed by the second air flow 30b, and the fibers are collected by the collecting member 4. Accordingly, a low-density and cotton-like fiber assembly can be stably obtained.

  In addition, generation | occurrence | production and irradiation of the ionizing radiation 10a can be performed continuously or discontinuously. Further, an electric field may be generated between the spinning nozzle 2 and the counter electrode 5, and a high voltage may be applied to only one of them and the other may be grounded. Further, the spinning nozzle 2 may be heated or not heated.

  In addition, when the ionizing radiation source 10 is used, the dose can be adjusted independently of the formation of a potential difference between the spinning nozzle 2 and the counter electrode 5, so that a fiber assembly can be obtained stably. It is.

  Moreover, various radiation sources can be used as the ionizing radiation source 10, and an X-ray irradiation apparatus is particularly desirable. The counter electrode 5 only needs to have a potential difference with the spinning nozzle 2, and may be grounded or a voltage may be applied. Further, the ionizing radiation source 10 only needs to be able to irradiate the fibers with radiation, and need not be located behind the counter electrode 5. Furthermore, the counter electrode 5 does not need to be net-shaped, and various members can be used as long as ionizing radiation can be transmitted, and even a metal vapor deposition film can be used.

  Unlike FIG. 5, instead of the ionizing radiation source 10, a creeping discharge element similar to the counter electrode is arranged between the spinning nozzle 2 and the net-like counter electrode 5, and ions are generated from the creeping discharge element. It can also act on the flying fiber to neutralize it. Also in this case, since ions can be generated and irradiated independently of the formation of a potential difference between the spinning nozzle 2 and the counter electrode 5, the irradiation amount of the ions can be easily controlled, and the cotton density is low. The fiber assembly can be produced stably.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the element same as above-described 1st Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 6 is a schematic view showing a fiber assembly manufacturing apparatus according to the second embodiment.

  As shown in FIG. 6, the fiber assembly manufacturing apparatus 1A includes a spinning chamber 3 for spinning fibers. The spinning chamber 3 has a main chamber 31 and sub chambers 32 and 33. The main chamber 31 is composed of a substantially rectangular parallelepiped casing, and includes a bottom wall portion 31d and an upper wall portion 31b that face each other in the vertical direction, and a right wall portion 31c and a left wall portion 31a that face each other in the horizontal direction. It is out. Each of the sub chambers 32 and 33 is configured by a substantially rectangular parallelepiped casing that is smaller than the main chamber 31. The sub chamber 32 is provided continuously to the left wall 31 a of the main chamber 31. The sub chamber 33 is provided continuously to the right side wall portion 31 c of the main chamber 31. Communication holes 41 and 42 are provided in a portion of the left side wall portion 31a of the main chamber 31 where the sub chamber 32 is provided and a portion of the right side wall portion 31c of the main chamber 31 where the sub chamber 33 is provided. The chamber 31 and the sub chamber 32 are in communication with the main chamber 31 and the sub chamber 33.

  In the sub chambers 32 and 33, a first spinning nozzle 2a (first polymer supply unit) and a second spinning nozzle 2b (second polymer supply unit) are provided so as to face each other in the horizontal direction. Yes. The first spinning nozzle 2a and the second spinning nozzle 2b supply a polymer solution as a fiber raw material to the spinning space in the main chamber 31. Here, to the first spinning nozzle 2a, a first polymer supply unit 6a for supplying a polymer solution, and a first high-voltage power source 7 (first charge applying unit) capable of applying a charge to the polymer solution; , Is connected. The second spinning nozzle 2b has a second polymer feeder 6b, a second high voltage power source 8 (second charge applying means) for applying a high voltage having a polarity opposite to that of the first high voltage power source 7, and Is connected.

  A collection member 4 (fiber collection device) such as a net or a conveyor is provided on the bottom wall 31d in the main chamber 31. The collected fiber 4 collects the spun fibers.

  Further, the fiber assembly manufacturing apparatus 1A is provided with a temperature / humidity control device 30 that sends an air flow into the spinning chamber 3 to control temperature and humidity. A first blower pipe 301 and a second blower pipe 303 are provided between the temperature / humidity control device 30 and the sub chambers 32 and 33, respectively, and the upper walls of the temperature / humidity control device 30 and the main chamber 31 are provided. A third blower pipe 304 is provided between the part 31b.

  When air currents are supplied from the temperature / humidity control device 30 to the sub chambers 32 and 33 through the first air duct 301 and the second air duct 303, the air currents pass through the communication holes 41 and 42, respectively. It is supplied into the main chamber 31 toward the two spinning nozzles 2b and the first spinning nozzle 2a. In this way, the temperature / humidity control device 30 and the first blower tube 301 constitute a first blower device, and the temperature / humidity control device 30 and the second blower tube 303 constitute a second blower device. It is configured. Further, when an air flow is supplied from the temperature / humidity control device 30 into the main chamber 31 through the third blower pipe 304, the air flow is supplied vertically downward from the upper wall portion 31b toward the bottom wall portion 31d in the main chamber 31. The Thus, the temperature / humidity control device 30 and the third blower tube 304 constitute a third blower.

  In the fiber assembly manufacturing apparatus 1 </ b> A according to this embodiment, the suction device 9 is connected to the bottom wall portion 31 d of the main chamber 31. When the suction machine 9 is operated, an air flow toward the collecting member 4 is generated in the main chamber 31. Therefore, when operating the suction device 9, the temperature / humidity control device 30, the third blower pipe 304, and the suction device 9 constitute a third blower device.

  In the present embodiment, the temperature and humidity control device 30 is shared by the first to third blowers, but a device such as a blower may be separately provided for the first to third blowers. Good.

  The rest of the configuration is the same as that of the fiber assembly manufacturing apparatus 1 in the first embodiment, and a duplicate description is omitted.

  Then, the manufacturing method of the fiber assembly by the electrostatic spinning method in 1 A of fiber assembly manufacturing apparatuses which concern on this embodiment is demonstrated. First, while applying voltages of opposite polarities to the first spinning nozzle 2a and the second spinning nozzle 2b by the first high voltage power source 7 and the second high voltage power source 8, respectively, the first spinning nozzle 2a and the second spinning nozzle 2b. The polymer solution is discharged from. Then, the fibers charged to opposite polarities are discharged to face each other and contact and approach to neutralize the charge, lose the flying force due to electrostatic force, fall according to gravity, and the fibers are collected by the collecting member 4. It is collected at. Accordingly, a low-density and cotton-like fiber assembly can be obtained.

  At this time, the first air flow 30a and the second air flow 30c are supplied from the sub-chambers 32 and 33 into the main chamber 31 from the temperature / humidity control device 30 through the first air duct 301 and the second air duct 303, respectively. By doing so, it is possible to prevent the electrically neutralized fibers from adhering to the first spinning nozzle 2a and the second spinning nozzle 2b, respectively. Further, by supplying the third air flow 30d from the temperature / humidity control device 30 to the main chamber 31 through the third blower pipe 304, the neutralized fibers supplied from the first spinning nozzle 2a and the second spinning nozzle 2b. Can be prevented from adhering to the opposing second spinning nozzle 2b and first spinning nozzle 2a. Therefore, a fiber assembly can be manufactured stably.

  Here, by adjusting so that the polymer solution discharge conditions from the first spinning nozzle 2a and the polymer solution discharge conditions from the second spinning nozzle 2b are different, the fiber diameter is different, the composition of the fiber constituent material is different, etc. A fiber assembly in which different kinds of fibers are mixed can be manufactured.

  In addition, the flow velocity of the first air flow 30a supplied by the first blower and the flow velocity of the second air flow 30c supplied by the second blower are the flow velocity of the third air flow 30d supplied by the third blower. Is faster. This effectively prevents the neutralized fibers supplied from the first spinning nozzle 2a and the second spinning nozzle 2b from adhering to the first spinning nozzle 2a and the second spinning nozzle 2b, respectively. The body can be manufactured more stably.

  The flow rates of the first air flow 30a and the second air flow 30c are 5 to 100 cm / sec. Is preferably 15 to 60 cm / sec. Is more preferable. 5 cm / sec. If the ratio is less than 1, the fibers ejected from the first spinning nozzle 2a and the second spinning nozzle 2b tend to adhere to the first spinning nozzle 2a and the second spinning nozzle 2b immediately after ejection, respectively, while 100 cm / Sec. This is because the fibers tend to adhere to the second spinning nozzle 2b and the first spinning nozzle 2a that face each other after discharge.

  Further, the flow rate of the third air flow 30d is 3 to 100 cm / sec. Is preferable, and 10 to 40 cm / sec. Is more preferable. 3 cm / sec. If the ratio is less than 100 cm / sec, the fibers tend to adhere to the first spinning nozzle 2a and the second spinning nozzle 2b. In this case, the fibers are strongly beaten against the collecting member 4 and the airflow suction force needs to be increased. Therefore, the fibers are not bonded to each other, or are low-density and cotton-like (bulky) fiber aggregates. This is because it tends to be difficult to manufacture.

  Furthermore, the following relationship between the flow velocity (referred to as f1) of the first air flow 30a, the flow velocity (referred to as f2) of the second air flow 30c, and the flow velocity (referred to as f3) of the third air flow 30d: Is preferably satisfied. That is, the percentage of the difference between f1 and f3 (fd1 = | f1-f3 |) with respect to the flow velocity of the slower airflow (preferably the third airflow 30d), and the difference between f2 and f3 (fd2 = | f2-f3 |) is preferably 10 to 200%, more preferably 50 to 100%, with respect to the flow rate of the slower air flow (preferably the third air flow 30d). preferable. Even if it is less than 10% or more than 200%, the balance of the air flow tends to be lost, and the fibers easily adhere to various places including the first spinning nozzle 2a and the second spinning nozzle 2b. This is because it tends to be difficult to stably produce the fiber assembly.

  Furthermore, it is preferable that the flow rates of the first air flow 30a and the second air flow 30c are substantially equal. Thereby, since fibers can be collected stably without disturbing the airflow in the spinning space, the fiber assembly can be manufactured more stably.

  In addition, discharge of the polymer solution from the 1st spinning nozzle 2a and the 2nd spinning nozzle 2b can be performed continuously or discontinuously. Moreover, an electric field should just generate | occur | produce between the 1st spinning nozzle 2a and the 2nd spinning nozzle 2b, a high voltage may be applied only to either of these, and the other may be earth | grounded. Further, the first spinning nozzle 2a and the second spinning nozzle 2b may be heated or unheated.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and various modifications are possible. For example, in the first to second embodiments described above, the spinning chamber 3 is provided, but the spinning chamber 3 is not necessarily required as long as the airflow and the temperature and humidity can be controlled.

  In the first to second embodiments described above, one spinning nozzle is used. However, the number of spinning nozzles is not necessarily one, and two or more spinning yarns are used to increase productivity. A nozzle may be provided.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example and a comparative example, this invention is not limited to this.

(Examples 1-9) and (Comparative Examples 1-3)
About (Examples 1-9) and (Comparative Examples 1-3), the polymer used for spinning, spinning conditions, fiber recovery states, and the like are summarized in the following table. In addition, about (Examples 1-8) and (Comparative Examples 1-3), the fiber assembly manufacturing apparatus 1 which concerns on 1st Embodiment is used, About (Example 9), the fiber which concerns on 2nd Embodiment. The assembly manufacturing apparatus 1A was used. As the spinning nozzle, a metal injection needle having an inner diameter of 0.4 mm (the tip was cut) was used. Further, as the counter electrode 5, the following A to E were used. That is,
A: A metal needle having a tip radius of curvature of 5 μm,
B: Tungsten wire with a diameter of 30 μm,
C: As shown in FIG. 4, an alumina film 26 (dielectric substrate) having a thickness of 1 mm is thermally sprayed on a stainless steel plate 28 (induction electrode), and a tungsten wire 27 (discharge electrode) having a diameter of 30 μm is coated thereon with a thickness of 10 mm. Creeping discharge elements stretched at equal intervals (the surface of the tungsten wire 27 is opposed to the spinning nozzle and grounded, and an AC high voltage of 50 Hz is applied between the stainless steel plate 28 and the tungsten wire 27 by the AC high voltage power supply 29),
D: Stainless steel mesh with a diameter of 0.1 mm and an opening of 5 mm,
E: A metal injection needle having an inner diameter of 0.4 mm (the tip was cut) was used.

Moreover, the following VZ was used as an ion irradiation means. That is,
V: counter electrode A (also serves as counter electrode),
W: counter electrode B (also serves as counter electrode),
X: counter electrode C (also serving as counter electrode),
Y: an ionizing radiation source capable of emitting soft X-rays (accelerated electron beam average output 10 W) having a maximum energy of 9.5 keV,
Z: A counter electrode E (also serving as a counter electrode) was used.

  The evaluation was made by judging whether spinning could be performed continuously for 30 minutes.

なお、表中、実施例７及び８、及び比較例１〜３における「ＳｉＯ₂ゾル」は、金属化合物としてテトラエトキシシラン、溶媒としてエタノール、加水分解のための水、及び触媒として１規定の塩酸を、１：５：２：０．００３のモル比で混合し、温度７８℃で１０時間の還流操作を行い、次いで、溶媒をロータリーエバポレーターにより除去して濃縮した後、温度６０℃に加温して形成した、粘度が２ポイズのゾル溶液である。また、表中の「ポリマー」は、それぞれＰＡＮ：ポリアクリロニトリル、ＤＭＦ：Ｎ，Ｎ−ジメチルホルムアミド、ＥｔＯＨ：エタノールである。また、表中の「気流」に関して、水平方向と鉛直方向の気流とは、（実施例１〜８）及び（比較例１〜３）については、それぞれ図１における第１の気流３０ａと、第２の気流３０ｂとを示し、（実施例９）については、それぞれ図６における第１及び第２の気流３０ａ，３０ｃと、第３の気流３０ｄとを示す。

In the Tables, “SiO ₂ sol” in Examples 7 and 8 and Comparative Examples 1 to 3 are tetraethoxysilane as a metal compound, ethanol as a solvent, water for hydrolysis, and 1N hydrochloric acid as a catalyst. Were mixed at a molar ratio of 1: 5: 2: 0.003, refluxed for 10 hours at a temperature of 78 ° C., concentrated by removing the solvent with a rotary evaporator, and then heated to a temperature of 60 ° C. A sol solution having a viscosity of 2 poises. The “polymers” in the table are PAN: polyacrylonitrile, DMF: N, N-dimethylformamide, and EtOH: ethanol. In addition, regarding the “airflow” in the table, the horizontal and vertical airflows are (first to eighth) and (comparative examples 1 to 3), respectively, the first airflow 30a in FIG. The second air flow 30b is shown, and (Embodiment 9) shows the first and second air flows 30a and 30c and the third air flow 30d in FIG. 6, respectively.

  As is clear from the table, according to the fiber assembly manufacturing method and the fiber assembly manufacturing apparatus according to the electrospinning method of Examples 1 to 9, a low-density and cotton-like fiber assembly is formed by using a spinning nozzle or a counter electrode. It was possible to manufacture stably without being attached to the surface.

(Example 10)
The fiber assemblies of Example 7 and Example 8 were dried at room temperature for 1 day and then baked at a temperature of 800 ° C. for 2 hours. The fiber assembly after firing was also a cotton-like assembly. Thus, the fiber assembly manufactured by the fiber assembly manufacturing method and the fiber assembly manufacturing apparatus according to the electrospinning method of Example 7 and Example 8 has a cotton-like bulky state even after firing. I found that it can be maintained.

It is the schematic which shows the fiber assembly manufacturing apparatus which concerns on 1st Embodiment of this invention. It is the schematic which shows the edge electrode immersed in the polymer solution. It is the schematic which shows the conveyor-like wire electrode immersed in the polymer solution. (A) is a schematic plan view which shows a creeping discharge element, (b) is a schematic side view which shows a creeping discharge element. It is the schematic which shows an ionizing radiation source. It is the schematic which shows the fiber assembly manufacturing apparatus which concerns on 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,1A ... Fiber assembly manufacturing apparatus, 2 ... Spinning nozzle, 2a ... 1st spinning nozzle, 2b ... 2nd spinning nozzle, 3 ... Spinning chamber, 4 ... Collection member, 5 ... Counter electrode, 5a ... Ion, 6 ... polymer supply machine, 6a ... first polymer supply machine, 6b ... second polymer supply machine, 7 ... first high voltage power supply, 8 ... second high voltage power supply, 9 ... suction machine, 10 ... ionizing radiation source, 10a ... Ionizing radiation, 11 ... third high voltage power source, 20 ... sawtooth gear, 20a ... tip, 20b ... wire, 21 ... polymer solution, 22 ... polymer solution container, 23 ... roller, 25 ... creeping discharge element, 26 ... dielectric Body substrate, 27 ... discharge electrode, 28 ... induction electrode, 29 ... alternating current high voltage power supply, 30 ... temperature and humidity control device, 31 ... main room, 31a ... left side wall, 31b ... upper wall, 31c ... right side wall, 31d ... bottom wall, 32, 33 ... subchamber, 301 ... first , Second air pipe, 304 third air pipe, 30a first air flow, 30b 30c second air flow, 30d third air current, 40, 41, 42 ... communication hole.

Claims (11)

Supplying a spinning polymer solution to the spinning space;
Supplying a first air stream in a direction to supply the polymer solution;
Irradiating the supplied and formed fibers with ions having a polarity opposite to the charge of the fibers;
Recovering the fibers while supplying a second air stream in a direction intersecting the direction of supplying the polymer solution and recovering the spun fibers;
A method for producing a fiber assembly by an electrospinning method, comprising:   The method for producing a fiber assembly by electrostatic spinning according to claim 1, wherein the flow velocity of the first air stream is faster than the flow velocity of the second air stream. Supplying polymer solutions of opposite polarities to the spinning space from opposite first and second positions;
Supplying a first air stream in a direction of supplying a polymer solution from the first position;
Supplying a second air stream in a direction to supply the polymer solution from the second position;
Collecting the fibers while supplying a third air stream in a direction intersecting a direction in which the first position and the second position face each other and collecting the spun fibers;
A method for producing a fiber assembly by an electrospinning method, comprising:   The method for producing a fiber assembly by electrostatic spinning according to claim 3, wherein the flow velocity of the first and second airflows is faster than the flow velocity of the third airflow.   5. The method for producing a fiber assembly by electrostatic spinning according to claim 3, wherein the flow velocity of the first air stream and the flow velocity of the second air stream are substantially equal. A polymer supply unit capable of supplying a polymer solution to the spinning space;
A charge imparting means capable of imparting a charge to the polymer solution;
A counter electrode facing the polymer supply section and capable of electrically sucking fibers formed by supplying the polymer solution;
Means capable of irradiating the fibers in flight between the polymer supply unit and the counter electrode with ions having a polarity opposite to the charge of the fibers;
A fiber recovery device that can recover the spun fiber;
A first air blower capable of supplying a first air stream in a direction from the polymer supply unit toward the counter electrode;
A second air blower capable of supplying a second air stream in a direction crossing the direction from the polymer supply unit toward the counter electrode and toward the fiber recovery device;
An apparatus for manufacturing a fiber assembly, comprising:   The fiber assembly manufacturing apparatus according to claim 6, wherein the ion irradiation means is an ionizing radiation source.   The apparatus for producing a fiber assembly according to claim 6 or 7, wherein the flow velocity of the first air stream is faster than the flow velocity of the second air stream. A first polymer supply unit capable of supplying a polymer solution to the spinning space;
First charge imparting means capable of imparting a charge to the polymer solution supplied from the first polymer supply unit;
A second polymer supply section facing the first polymer supply section and capable of supplying a polymer solution to the spinning space;
A second charge imparting means capable of giving a charge having a polarity opposite to that of the polymer solution supplied from the first polymer supply unit to the polymer solution supplied from the second polymer supply unit;
A fiber recovery device that can recover the spun fiber;
A first blower capable of supplying a first air stream in a direction from the first polymer supply unit toward the second polymer supply unit;
A second air blower capable of supplying a second airflow in a direction from the second polymer supply unit toward the first polymer supply unit;
A third blower capable of supplying a third airflow in a direction crossing the direction in which the first polymer supply unit and the second polymer supply unit face each other and toward the fiber recovery device;
An apparatus for manufacturing a fiber assembly, comprising:   10. The fiber assembly manufacturing apparatus according to claim 9, wherein the flow velocity of the first and second airflows is faster than the flow velocity of the third airflow.   11. The fiber assembly manufacturing apparatus according to claim 9, wherein the flow velocity of the first air flow and the flow velocity of the second air flow are substantially equal.

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