KR20150040114A - Method and equipment of preparing non-woven material, non-woven material produced by the method, separator for battery and electrochemical battery comprising the non-woven material - Google Patents

Abstract

The present invention relates to a method and an apparatus for preparing a non-woven material using an electrospinning method, and uses thereof. According to one aspect of the invention, the method comprises: a step of preparing a spinning solution by dissolving a raw material of the non-woven material in a solution; a step of injecting the spinning solution into a syringe of a positive electrode; a step of spinning nanofibers in a rotary collector of the negative electrode having a certain rotating speed; and a step of stacking the spun nanofibers on the collector, and aligning the nanofibers in a rotary direction of the collector. According to another aspect of the invention, the apparatus comprises: a reservoir for storing a spinning solution; a positive electrode syringe for receiving the spinning solution from the reservoir; a pump for pumping the spinning solution from the syringe; a negative electrode rotary collector for receiving the spinning solution from the pump; a rotating controller for controlling the rotating speed of the collector; and a power supply for supplying the power to the syringe, the pump, the collector and the rotating controller. According to the present invention, a non-woven material is manufactured in a simple manner, capable of adjusting its thickness, and has high mechanical properties.

Description

TECHNICAL FIELD The present invention relates to a nonwoven fabric manufacturing method and apparatus, a nonwoven fabric manufactured by the method, a separator for a battery including the nonwoven fabric, and an electrochemical cell produced by the method electrochemical battery comprising the non-woven material}

The present invention relates to a method for producing a nonwoven fabric, specifically, a method for manufacturing and manufacturing a nonwoven fabric using an electrospinning method, a nonwoven fabric manufactured by the method, a separator for battery including the nonwoven fabric, and an electrochemical cell.

The nonwoven fabric has been widely used in various fields such as disposable articles, artificial bio-similar articles, artificial leather, automobile interior materials, civil engineering, architecture, agriculture, filters, electrochemical cells and the like due to its excellent air permeability, heat insulation property and non- . Methods for producing such nonwoven fabrics include dry, wet, spun-lamination, electrospray, and the electrospinning process is the most popular method in the production of nanofibers in the electrospray process.

Electrospinning is a method patented by Formhals in the early 20th century as a scientific basis for the calculation that Raleigh in the late 19th century can overcome the surface tension of electrostatic force when liquid drops.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a conventional apparatus for manufacturing electrospinning for producing a nonwoven fabric. Electrospinning is a method of obtaining a product by spinning a polymer of low viscosity instantaneously in the form of a fiber by electrostatic force to form a product or a syringe by providing a high voltage to a solution or melt of the polymer (e.g., droplet-like spinning solution) Is a method of producing fibers or particles by forming an electrostatic force between an end portion (e.g., a portion of a syringe portion closest to a collector, a nozzle, a capillary tube, etc.) and a collector. The principle of such electrospinning is that when the intensity of the electrostatic force is equal to the surface tension of the polymer droplet, the polymer droplet with the charge is formed at the end of the syringe (hemisphere drop shape) The charged polymer droplets are not stabilized and are dispersed in the ground direction (cone droplets (also known as Tayler cones) as a jet shape). Eventually, the dispersed polymer droplets are focused on the collector in the form of fibers and particles. As the electric field increases, the spinning solution at the tip of the syringe is deformed from the hemispherical droplet to the tail cone. When the electric field is further increased, the repulsive electrostatic force is higher than the surface tension of the polymer by electrospinning And is emitted in a thin fiber form in a Taylor cone with electrostatic force. However, the nonwoven fabric fibers thus produced are lacking in mechanical properties, and therefore, there are still restrictions on the fields to which they are applied. Therefore, studies have been continued to investigate the influence of spinning solution, process parameters, etc. of the target fiber to be produced on the structure of the final fiber.

On the other hand, a number of methods for producing nonwoven fabrics have been disclosed. For example, there is disclosed a technique disclosed in International Publication No. WO 1999/64649 (Tencel Ltd., International Publication, December 16, 1999) The method comprising: spinning a cellulose solution in an amine oxide solvent through one or more spinning jets, contacting the extruded filaments with a high velocity gas stream to produce fibers, and at least partially coagulating the fibers before collecting the fibers into the web And passing through a steam mist to produce a nonwoven fabric.

It is an object of the present invention to provide a method for producing a nonwoven fabric in which mechanical properties are improved by imparting a certain orientation to the nonwoven fabric.

Other objects and advantages of the present invention will become apparent from the following description. It is also to be easily understood that the objects and advantages of the present invention can be realized by the means or method described in the claims, and the combination thereof.

In order to solve the above-mentioned problems, the present invention adjusts the rotary collector to a certain increased rotational speed in the spinning process of spinning solution.

According to one aspect of the present invention, there is provided a method for producing a spinning solution, comprising the steps of: dissolving a nonwoven fabric raw material in a solvent to prepare a spinning solution; Injecting the spinning solution into a syringe of a (+) electrode; Irradiating the injected spinning solution with nanofibers to a rotary collector of a (-) electrode having a predetermined rotation speed; And laminating the spun nanofibers on the collector and orienting the nanofibers in a rotating direction of the collector.

According to another aspect of the present invention, there is provided a storage tank for storing a spinning solution; A (+) electrode syringe for receiving a spinning solution from the reservoir; A pump for pumping a spinning solution from the syringe; A rotating collector of the negative electrode for receiving the spinning solution from the pump; A rotation controller for controlling a rotation speed of the collector; And a power source for supplying electricity to the syringe, the pump, the collector, and the rotation controller.

According to still another aspect of the present invention, there is provided a nonwoven fabric manufactured by the manufacturing method, a separator for a battery including the nonwoven fabric, And a secondary battery such as an electrochemical cell such as a lithium secondary battery in which the separator is interposed between the positive electrode and the negative electrode.

According to the present invention, it is possible to produce a nonwoven fabric by a relatively simple method, and the nonwoven fabric thus produced is capable of controlling the thickness and is excellent in mechanical properties.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given above, serve to better understand the spirit of the invention. And should not be construed as limiting.
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a conventional apparatus for manufacturing electrospinning for producing a nonwoven fabric.
2 is a schematic flow chart of a method for producing a nonwoven fabric using the electrospinning method of the present invention.
3 is a schematic view of an apparatus for producing a nonwoven fabric of the present invention.

Hereinafter, the present invention will be described in detail. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor may designate the concept of a term appropriately in order to describe its own invention in the best way possible. It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the constitution described in the embodiments of the present invention is merely an embodiment of the present invention, and does not represent all the technical ideas of the present invention, so that various equivalents and modifications It should be understood.

2 is a schematic flow chart of a method for producing a nonwoven fabric using the electrospinning method of the present invention. According to the present invention, a process of adjusting the rotation speed of the trapper in the course of radiating from the syringe to the rotary trapper may be included. 2, according to an aspect of the present invention, there is provided a method of manufacturing a spinning solution, Injecting into a syringe; The spinning phase of nanofibers; And a step of orienting the nanofibers.

As used herein, the term "nonwoven fabric" refers to a nonwoven fabric that can be formed by chemical action (e. G., By blending an adhesive in a fiber), by mechanical action or by suitable moisture and heat treatment, Cloth) shape.

First, a spinning solution is prepared by dissolving a nonwoven fabric raw material in a solvent. The nonwoven fabric raw material used in the present invention can be selected to suit the application to which the nonwoven fabric is to be applied. After selecting the nonwoven fabric raw material, a solvent suitable for dissolving the nonwoven fabric raw material is dissolved in the raw material through a process such as mixing and / or stirring. The solution of the dissolved nonwoven fabric raw material and the solvent is prepared as a solution (that is, a spinning solution) for spinning into a collector through a syringe.

Examples of the raw material for the nonwoven fabric include polyethyleneterephthalate, polybutyleneterephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyimide, polyimide, polyetheretherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylether, polyetherketone, Polyolefins such as polyphenylene oxide, cyclic olefin copolymer, polyphenylenesulfide, polyvinyl alcohol, polyacrylic acid, polyethylene oxide, polyethylene- Polyvinyl alcohol copolymer, polyethylene naphthalene, protein But are not limited to, fibers, biodegradable polymers, conductive polymers, glass fibers, and celluloses and derivatives thereof. Such nonwoven fabric raw materials can be used for applications such as battery separator, bio-similar protein fiber, artificial skin, artificial ligament, functional fabric, conductive polymer nanofiber, semiconductor surface abrasive, high performance filter, sound absorbing material or flooring material. Can be selected and used.

Other examples of nonwoven raw material materials include, but are not limited to, acrylic, vinylon, pitch, and the like. The nonwoven fabric raw material may also be selected and used depending on the application.

The solvent may be selected differently depending on the selected nonwoven fabric raw material. Examples of such solvents include water, acetone, tetrahydrofuran (THF), dioxane, monoglyme, diglyme, dimethyl sulfoxide (DMSO), dimethyl sulfoxide N-methyl-2-pyrrolidone (NMP), normal hexane (normal hexane), dimethylformamide (DMF) hexane, cyclohexane, benzene, toluene, chlorobenzene, dichlorobenzene, methylene chloride or 1,2-dichloroethane, ), Mixtures thereof, and the like. The solvent is preferably similar to the solubility index of the solute to be dissolved, i.e., the nonwoven raw material. The solvent can be dissolved in the nonwoven raw material at a concentration of about 10 to about 40 wt%, but this concentration can be selected differently depending on the chemical structure or molecular weight of the selected nonwoven raw material.

Then, the prepared spinning solution is injected into a syringe. Here, the syringe is in electrical communication with the power source and has (+) electrodes. Also, the syringe may have a spinning nozzle towards the collector and the syringe or nozzle thereof may have a predetermined diameter, and such a diameter may be adjusted according to the desired diameter size of the nonwoven fabric. The aperture may be, but is not limited to, about 20 to about 40 gauge.

Further, the spinning solution in the injector injects the nanofibers toward the collector. Typically, in electrospinning, the properties of the spinning solution (e.g., concentration, viscosity, surface tension, conductivity, viscoelasticity, polarity, etc.), distance from the tip of the syringe (nozzle) , The spinning speed, the spinning environment, and the like, the shape or properties of the final formed fibers are changed. This will be described in detail as follows.

When the concentration of the spinning solution is low, the polymer accumulates in the form of droplets, and as the concentration becomes higher, it forms a stable fiber phase through the hairy droplet shape. Also, as the viscosity of the spinning solution increases, the degree of entanglement of the polymer chains increases, which interferes with the collapse of the jet, so that the jet is stretched into fibers. In other words, these jets collapse into fine droplets due to surface tension in the case of low viscosity solutions. However, in the case of a highly viscous solution, the jet is not collapsed but the solvent is evaporated as the air is blown toward the collector and the charged continuous fibers are accumulated in the collector. As the jet flies toward the trap, the trajectory of the jet may bend or change direction. In addition, the jet tapers during flight and the charge is densely packed on the surface, causing the initial jet to split into several smaller filaments by charge repulsion. This process is referred to as splaying.

In addition, the distance from the end of the syringe to the collector is such that, if this distance is too short, the spinning solution containing the solvent will reach the collector and will adhere to each other in the course of drying, so about 5 to about 50 cm, To about 20 cm.

Also, increasing the strength of the electric field increases the overall charge density of the jet, resulting in a thinner fiber, so that the applied voltage of the syringe and the rotary collector can be about 10 to about 30 kV. Moreover, the droplet type fibers are the result of the jet collapsing due to the deformed surface tension under the electric field. The main factors affecting the formation of such droplet type fibers are the viscosity of the spinning liquid, the total charge density of the jet, Surface tension. When the viscosity of the spinning solution is high, a fiber having no drop shape is produced. The higher the viscosity, the longer the distance on the droplet and the larger the droplet becomes, but the shape changes from spherical to Taylor cone, for example a spindle shape. The higher the total charge density, the more fibers can be produced as well as the fibers without drop form.

In another embodiment of the invention, the trap is rotationally controlled by, for example, an external controller (e.g., a rotation controller) and is adjusted to a predetermined relatively rapid rotation. The centrifugal force is increased by high-speed rotation of the collector when the speed of rotation is within the range of the fast rotation speed, thereby increasing the orientation of the nonwoven fabric to be formed on the surface of the collector, in the rotating direction of the collector. Thus, high speed rotation of the collector increases the mechanical strength of the nonwoven fabric.

The collector also communicates electrically with the power source as a (-) electrode. The rate of radiation from the syringe to the trap can be adjusted at a constant, random, or programmed rate. In one embodiment of the invention, the spinning rate may be from about 5 to about 100 ml / min, such as from about 10 to about 30 ml / min. Fabricating at this range of radial velocities can result in fibers with a uniform surface without the formation of droplet-like fibers such as beads.

In another embodiment of the present invention, the spinning process may be carried out in a random or constant pattern. Here, the expression "random pattern" refers to the fact that yarns or filaments of a nonwoven fabric to be produced are positioned without regularity with respect to each other, and the expression " It means having sex.

This random or constant pattern of radiation can basically vary depending on the radiation pattern of the syringe (nozzle), and optionally can also be achieved by adjusting the spinning speed and the rotational speed of the collector as described above. As known in the art, depending on the pattern of such a nonwoven fabric, it may affect bonding property, productivity, workability, peelability and the like.

Next, the spun nanofibers are laminated on the collector, and the nanofibers are oriented in the rotating direction of the collector to produce a nonwoven fabric.

As mentioned earlier, the radiation from the syringe to the rotary trap can basically be controlled by the rotation speed of a certain range of the trap. By the rapid rotation of the collector in this range, the centrifugal force of the collector is increased, and the centrifugal force is also applied to the nonwoven fabric to be formed on the surface of the collector by this. This centrifugal force increases the orientation of the nonwoven fabric in the direction of rotation of the collector, and as a result, the unidirectional orientation of the nonwoven fabric increases the mechanical strength of the nonwoven fabric.

In addition to the rotational speed of the above-described collecting device, it is also possible to use the above-mentioned rotational speed of the collecting device and the rotational speed of the syringe such as mentioned in the description of the spinning solution, the syringe (nozzle) diameter, the concentration and viscosity of the spinning solution, As such, these specific controlled emissive and entrapment processes increase the orientation of the nonwoven fabric nanofibers and thereby the mechanical strength of the resulting nanofibers, either alone or in combination of two or more of these processes.

Another embodiment of the present invention is a nonwoven fabric produced by the above-described manufacturing method. In another embodiment, there is provided a separator for a battery, a bio-like protein fiber, an artificial skin, an artificial ligament, a functional fabric, a conductive polymer nanofiber, a semiconductor surface abrasive, a high performance filter, a sound absorbing material or a floor material, It does not.

Another embodiment of the present invention is a separator for a battery comprising a nonwoven fabric produced by the above production method.

The separation membrane according to one aspect of the present invention may be useful as a separation membrane of an electrochemical device, that is, a separation membrane interposed between an anode and a cathode.

The electrochemical device according to one aspect of the present invention includes all devices that perform an electrochemical reaction, and specific examples thereof include capacitors such as all types of primary cells, secondary cells, fuel cells, solar cells, or super capacitor devices ). In particular, a lithium secondary battery including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion polymer secondary battery may be included in the secondary battery.

The electrode to be applied together with the separator according to an aspect of the present invention is not particularly limited, and the electrode active material may be bound to an electrode current collector according to a conventional method known in the art. Examples of the cathode active material include, but are not limited to, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or a combination thereof A lithium complex oxide may be used. As a non-limiting example of the negative electrode active material, a conventional negative electrode active material that can be used for a negative electrode of an electrochemical device can be used. In particular, lithium metal or a lithium alloy, carbon, petroleum coke, activated carbon, Lithium adsorbing materials such as graphite or other carbon-based materials and the like can be used. Non-limiting examples of the positive current collector include aluminum, nickel, or a combination thereof. Examples of the negative current collector include copper, gold, nickel, or a copper alloy or a combination thereof Foil to be manufactured, and the like.

The electrolyte solution which can be used in the electrochemical device according to one aspect of the present invention is a salt having a structure such as A ⁺ B ^- , wherein A ⁺ is an alkali metal cation such as Li ⁺ , Na ⁺ , K ⁺ And B ^- is a metal ion such as PF ₆ ^- , BF ₄ ^- , Cl ^- , Br ^- , I ^- , ClO ₄ ^- , AsF ₆ ^- , CH ₃ CO ₂ ^- , CF ₃ SO ₃ ^- , N (CF ₃ SO ₂ ) _{^{2 -, C (CF 2 SO}} 2) 3 - anion, or a salt containing an ion composed of a combination of propylene carbonate (PC) such as, ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC ), Dimethyl carbonate (DPC), dimethylsulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethylmethyl carbonate (G-butyrolactone), or an organic solvent composed of a mixture thereof, but is not limited thereto It is not.

The electrolyte injection may be performed at an appropriate stage of the battery manufacturing process, depending on the manufacturing process and required properties of the final product. That is, it can be applied before assembling the cell or at the final stage of assembling the cell.

As a process for applying a separator according to an aspect of the present invention to a battery, a lamination, stacking and folding process of a separator and an electrode can be performed in addition to a conventional winding process.

According to another aspect of the present invention, there is provided a nonwoven fabric manufacturing apparatus having a rotary collector and a syringe capable of adjusting the rotation speed in the spinning process, for example, to impart improved mechanical properties.

3 is a schematic view of an apparatus 300 for manufacturing a nonwoven fabric of the present invention. 3, according to another aspect of the present invention, there is provided a method of dispensing fluid comprising a reservoir 310, a syringe 320, a pump 330, a rotatable collector 340, a rotation controller 350 and a power source 360 A nonwoven fabric manufacturing apparatus 300 is provided.

First, the storage tank 310 of the nonwoven fabric manufacturing apparatus 300 is a constituent element for storing the spinning solution 311. The spinning liquid 311 is a solution formed by dissolving a nonwoven raw material (not shown) in a solvent (not shown) as described above. The nonwoven fabric manufacturing apparatus 300 is equipped with a syringe 320 having a (+) electrode as a component for receiving the spinning solution 311 from the storage tank 310. The spinning liquid 311 of the syringe 320 may be pumped by a pump 330. The pumping speed (e.g., spin speed) of such a pump 330 may be adjusted by a pumping controller (not shown), which may be internal or external to the nonwoven fabric manufacturing apparatus 300.

The collector 340 has a rotational shape of a (-) electrode as a component for receiving the spinning solution 311 from the injector 320. This sorter 340 may have a range of rotational speeds to enhance the mechanical strength of the resulting fibers. The rotation speed of the collector 340 may be controlled through the rotation controller 350. The centrifugal force is increased by the high speed rotation of the collecting unit 340. This causes the nonwoven fabric to be radiated on the surface of the collecting unit 340 to be oriented in the rotating direction of the collecting unit 340 . Thus, the high-speed rotation of the collector 340 raises the mechanical strength of the nonwoven fabric.

The power supply 360 supplies electricity to the reservoir 310, the syringe 320, the pump 330, the collector 340, and the rotation controller 350. Electrospinning uses a high voltage to obtain the polymer spinning solution (i.e., polymer solution or melt) 311 in the form of a jet. The spinning solution 311 is spin coated on the surface of the collector 340 to supply electricity to the spinner 320 so that the spinning solution 311 is stuck due to its own tension. One electrode (e.g., (+) electrode) of the electrode is positioned in the syringe 320, e.g., the spinning solution 311 thereof, and the other electrode (e.g., , The polymer spinning solution 311 is produced as a polymer filament. When the polymer spinning liquid 311 is radiated from the syringe 320 having a small hole, the polymer spinning solution 311 is evaporated and collected into the collector 340 in the form of fibers. Here, the potential difference depends on the characteristics of the spinning solution 311, the molecular weight of the polymer, the viscosity, and the like. If the distance between the syringe 320 and the sorter 340 is short, the radiated fibers tend to become entangled with each other on the sorter 340 because evaporation of the solvent is not sufficient.

In another embodiment of the present invention, the apparatus 300 for fabricating the nonwoven fabric is characterized in that the reservoir 310 has two or more inlets (not shown), at least one of which is made of a nonwoven raw material And at least one of the other injection ports injects a solvent (not shown). The desired spinning solution 311 can be prepared by injecting the raw material of the nonwoven fabric and the solvent in the form of one or more kinds of the above-mentioned materials through the two or more injection ports, and dissolving them by mixing and / or stirring .

In another embodiment of the present invention, the apparatus 300 for fabricating a nonwoven fabric is characterized in that the syringe 320 performs radiation in a random or uniform pattern. Here, the injector 320 can achieve this random or uniform pattern of radiation by adjusting the radiation pattern either by itself or by structural modification of a nozzle (not shown). In addition, a random or uniform pattern of radiation can be achieved by controlling the spinning speed by the aforementioned pumping controller (not shown) and by controlling the rotational speed of the collector 340 by the spin controller 350.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the above-described embodiments. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

Claims (13)

Dissolving the nonwoven fabric raw material in a solvent to prepare a spinning solution;
Injecting the spinning solution into a syringe of a (+) electrode;
Irradiating the injected spinning solution with nanofibers to a rotary collector of the (-) electrode; And
Laminating the spun nanofibers on the collector, and orienting the nanofibers in a rotating direction of the collector. The method according to claim 1,
Wherein the nonwoven fabric raw material is selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, Polyetheretherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene oxide, polyetheretherketone, polyetheretherketone, polyetheretherketone, polyphenylene oxide, cyclic olefin copolymer, polyphenylenesulfide, polyvinyl alcohol, polyacrylic acid, polyethylene oxide, polyethylene-polyvinyl alcohol, Alcohol copolymer, polyethylene naphthalene (polyethylenenaphthalene), protein island The method of producing a non-woven fabric, characterized in that one or more selected from biodegradable polymers, the group consisting of a conductive polymer, a glass fiber, and cellulose and derivatives thereof. The method according to claim 1,
Wherein the solvent is selected from the group consisting of water, acetone, tetrahydrofuran (THF), dioxane, monoglyme, diglyme, dimethyl sulfoxide (DMSO), dimethylacetate (DMAC), chloroform, dimethyl formamide (DMF), N-methyl-2-pyrrolidone (NMP), normal hexane, Cyclohexane, benzene, toluene, chlorobenzene, dichlorobenzene, methylene chloride, 1,2-dichloroethane, or the like. Or a mixture thereof. The method according to claim 1,
Wherein the voltage applied to the syringe and the rotary collector is 10 to 30 kV. The method according to claim 1,
Wherein the spinning speed is in the range of 5 to 100 ml / min. The method according to claim 1,
Wherein said spinning is carried out in a random or constant pattern. A nonwoven fabric produced by the manufacturing method according to any one of claims 1 to 6. A separator for a battery comprising the nonwoven fabric according to claim 7. An electrochemical cell comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, wherein the separator is the separator for a battery according to claim 8. 10. The method of claim 9,
Wherein the electrochemical cell is a lithium secondary battery. A reservoir for storing the spin solution; A (+) electrode syringe for receiving a spinning solution from the reservoir; A pump for pumping a spinning solution from the syringe; A rotating collector of the negative electrode for receiving the spinning solution from the pump; A rotation controller for controlling a rotation speed of the collector; And a power source for supplying electricity to the syringe, the pump, the collector, and the rotation controller. 12. The method of claim 11,
Wherein the reservoir has two or more injection ports,
Wherein at least one of the injection ports injects a raw material for the nonwoven fabric, and at least one of the other injection ports injects a solvent. 12. The method of claim 11,
Wherein the irradiation of the syringe is performed in a random direction or in a predetermined pattern.

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