KR20050041201A - A method producing nano fiber with wide width - Google Patents

Abstract

The present invention relates to a method for manufacturing a wide nanofiber, and more particularly, to increase the overall radiation area to form a wide film or to coat a wide surface of nanofiber, and to produce a wide film at once without repeated spinning operations. As a method for mass production of wide nanofibers, a) a polymer solution is rotated and driven by a rotating device and its driving part, and includes a plurality of electrospinning nozzle holes on each lower surface which are offset from the center of the rotating shaft. Feeding at least two regularly arranged rotary emitters; b) rotating the polymer solution eccentrically by the rotating device, and discharging the polymer solution through an electrostatic spinning nozzle to which a high voltage is applied; And c) collecting the emitted fibers on a lower grounded recruitment electrode.

Description

Manufacturing method of wide nanofibers {A METHOD PRODUCING NANO FIBER WITH WIDE WIDTH}

The present invention relates to a method for manufacturing a wide nanofiber, and more particularly, a) a plurality of electrostatic spinning nozzle holes are rotatably driven by a rotating device and its driving unit, and are offset from the center of the rotating shaft. Supplying to at least two regularly arranged rotary emitters comprising; b) rotating the polymer solution eccentrically by the rotating device, and discharging the polymer solution through an electrostatic spinning nozzle to which a high voltage is applied; And c) collecting the emitted fibers on a lower grounded recruitment electrode.

As shown in FIG. 1, electrostatic radiation is applied to a polymer solution or melt in a nozzle, and then the capillary tube is brought into balance with the surface tension and the electrical stress of the liquid. The liquid droplets formed at the end are deformed into a pointed cone shape and the liquid is radiated. The fiber spun as described above is accelerated and thinned by an electric field, becomes unstable, and collects on the surface of the grounded metal, which is a recruitment electrode, in a discontinuous form. In other words, when a material dissolved in a solution has a low molecular weight, it is generally referred to as electrostatic spraying because it has a small particle shape. However, when a material having a high molecular weight is electrospun, it is generally about 100 nm. Fibers with very small diameters are obtained in the form of fibers which are not oriented or regular. Therefore, the process of obtaining fibers from such a high molecular weight polymer is called electrostatic spinning process to distinguish it from the electrospray process.

However, in the case of the electrospinning method described above, the radial surface formed through one nozzle has a diameter due to the problem of the allowable voltage, the limit of the distance between the nozzle and the recruiting electrode, and the limit of the voltage that can be generated. It did not exceed the level of about 5-10 cm.

Therefore, such a narrow radiation area is not able to form a wide film, the difficulty of mass production occurs. In addition, even when coating the nanofibers on the fiber layer due to the problem of coating the fiber layer by dividing several times, the process time is long, there was a problem that the productivity is low.

In order to solve this problem, it is necessary to develop a nanofiber manufacturing method capable of mass-producing a wide nanofiber film by spinning evenly at a wide width of 1 m or more at once.

In order to solve the problems of the prior art as described above, an object of the present invention is to provide a method for producing a nanofiber to increase the overall radiation area to form a wide film or to coat a wide fiber surface.

In addition, an object of the present invention is to provide a method for producing nanofibers that can produce a wide film at a time without repeated spinning.

In addition, the present invention can minimize the generation of arc under the high turnover voltage between the nozzle and the recruitment electrode, and stably radiate the polymer solution even during the movement or rotation of the nozzle, the nano-fiber nanofiber can be produced by expanding the radiation area It is an object to provide a method for producing a fiber.

In another aspect, the present invention is to provide a method for producing nanofibers that can be easily made without spinning the electric power to mass production and uniformly radiate the nanofibers in a straight line to form a uniform thickness and easier to manufacture thereof. The purpose.

In addition, an object of the present invention is to provide a nanofiber manufacturing method that is easy to mass production because the electric field between the nozzle and the recruitment electrode is uniformly formed and the spinning of the nanofiber is wide and uniform.

In order to achieve the above object, the present invention includes a) a plurality of electrostatic spinning nozzle holes, each of which is driven by the rotating device 30 and its driving unit 25 and offset from the center of the rotating shaft, on each lower surface thereof. Feeding at least two regularly arranged rotary emitters; b) rotating the polymer solution eccentrically by the rotating device (30) and discharging it through an electrostatic spinning nozzle to which a high voltage is applied; And, c) collecting the released fibers on the lower grounded recruitment electrode 20.

Hereinafter, the present invention will be described in detail.

The polymer used in the present invention is a compound that is a raw material of the nanofibers 45 and is a material that can be dissolved by a solvent.

The polymer may be any kind of polymer capable of electrospinning according to the use of the nanofiber 45, for example, when the nanofiber 45 is used for industrial purposes, nylon, polyethylene, polypropylene, or cellulose It is preferable to use such as economical.

Since the solvent in the polymer solution to be used in the present invention may be suitable for dissolving the polymer, those skilled in the art can be selected and used according to the type of polymer. In particular, the polymer solution is preferably 1000 cps ~ 5000 cps viscosity. If the viscosity of the polymer solution is within the above range it is easy to control the electrospinning and morphology (morphology) of the nanofibers (45).

The polymer solution is supplied to the above-mentioned electrostatic spinning nozzle module by a metering pump, and the pressure at this time can be adjusted according to the magnitude of the voltage across both ends, and can generally be adjusted to 0.4-1.0 kg / cm 2.

The rotatable emitter 15 includes a rotatable device 30 that can rotate as shown in FIG. 2 and a driving unit 25 for driving the rotary device 30 to rotate. The polymer solution is discharged to the recruitment electrode 20. In order to increase the radiation area of the formed nanofibers 45, it is necessary to rotate the emitter 15 including a plurality of nozzles. For this purpose, the rotary device 30 capable of rotating the emitter 15 and its driving unit (25) is required. An example of the rotary device 30 may be a union structure, and the rotary drive unit 25 may use various types of drive devices such as a direct current (DC) motor or an alternating current motor. In addition, of course, the system may further include a driving control unit for adjusting the rotation speed of the rotating device.

The rotating device 30 is connected to the rotary emitter 15 to configure the emitter 15 to be self-rotating. That is, the polymer solution discharged from the nozzle by the centrifugal force generated by the rotational movement of the rotary ejector is radiated to a wider range and can achieve the above purpose. To maximize the centrifugal force, the position of the nozzle is rotated. It is desirable to space as far as possible from the central axis of the emitter 15. Therefore, in order to maximize the generation of centrifugal force, the lower surface of the rotary ejector 15 is preferably configured in a circular shape.

The lower end of the circular rotary emitter 15 can be configured by varying the plurality of nozzle holes, in particular, can be adjusted to about 4 to 16 for the radiation area and uniform radiation,

In addition, the electrospinning nozzle is an embodiment of the manufacturing apparatus according to the present invention, as shown in Figures 3 and 5, the end of the nozzle can be made perpendicular to the nozzle hole. That is, the nozzle end forms a shape perpendicular to the nozzle hole, and the end of the nozzle is horizontal with respect to the recruitment electrode. In this case, the electric field between the nozzle and the recruiting electrode can be developed evenly, and the area where the distance between the two parts becomes short in the local part does not occur. Therefore, it is possible to minimize the arcing phenomenon that may occur during the manufacturing of the nanofibers (45).

In addition, the rectangular nozzle is advantageous in terms of shape management and standardization of the nozzle, and FIG. 2 shows a schematic view of the rotary ejector 15 using the rectangular nozzle according to an embodiment of the present invention. In this case, the electrospinning emitter 15 rotates to release the polymer solution. In the same rotation, the rectangular nozzle has an effect of increasing the spinning area of the polymer solution compared to the general nozzle. The solution is directed outwards, and the edge of the nozzle and the solution interact with each other so that the polymer solution is directed outwards as compared with a general round nozzle.

 The shape of the nozzle may use a variety of known nozzles. In particular, a needle-type nozzle 10 having a microtubule shape or a microporous nozzle formed by processing the microhole 70 on the lower surface of the ejector may be exemplified. In the case of the needle nozzle 10, it is difficult to manufacture and assemble, and requires careful management of the needle in terms of management of the equipment, and the needle in the case of rotating the rotary ejector or moving the rotary ejector left and right Since problems such as shaking of the mold nozzle 10 may occur, the microhole 70 is processed on the lower surface of the emitter as a method of solving such a problem, and thus has the same configuration as that of the needle-type nozzle 10 while having a rigid shape. It is possible to manufacture a nozzle of, and the structure is simpler than the needle type has the advantage of manufacturing a larger number of nozzle holes.

The nozzle of the form which processed the said microhole 70 can also add a wire to the said nozzle. That is, the wire-type electrospinning nozzle is, as an example, as shown in FIGS. 6 and 7, the upper portion of which is connected to the lower portion of the electrospinning emitter 15, the lower surface of which is blocked and arranged in a straight line passing through the lower surface. A volume 65 of body portion including a hole 70; And a wire 60 parallel to the arrangement of the micro holes 70 and spaced apart from the micro holes by a predetermined distance, and both ends of which are fixed to the inner wall of the body. A constant volume body portion 65 connected to the lower part of the emitter 15 and including a microhole 70 arranged in a straight line through which the lower surface is blocked and penetrates the lower surface; And a wire 60 parallel to the arrangement of the micro holes and spaced apart from the micro holes 70 by a predetermined distance, and both ends of which are fixed to the fixing protrusion protruding downward from the outer circumferential surface of the lower surface of the body. It can be configured in the form.

That is, the wire 60 should be arranged in the form of a parallel movement down or up in each linear arrangement to correspond to the linear arrangement of the micro holes 70. That is, when positioned below the nozzle, the circumferential surface of the body portion 65 may be extended to form a circumferential protrusion as shown in FIG. 6, and both ends of the wire 60 may be fixed to the protrusion or the wire 60 may be formed. Only the parts connected to both ends of the fixing protrusions can be formed. In addition, when the wire 60 is located above the nozzle, both ends of the wire 60 may be fixed to the inner wall surface of the body portion 65 without the need for the manufacture of a separate projection.

The material of the wire 60 may be any conductor and use the same material as the nozzle in terms of ease of manufacture and corrosion prevention, or use copper having excellent conductivity, stainless steel having excellent corrosion resistance, and the like.

In the case where the nozzle includes the wire 60 charged with the voltage as described above, the voltage on the wire 60 and the voltage of the nozzle become an equipotential surface, so that the polymer solution away from the nozzle wall surface is close to the wire 60. If present, the polymer can be strongly charged, thereby preventing the decrease of the electric force of the polymer solution. In addition, one or more wires 60 included in the electrostatic spinning nozzle may be included.

In addition, the nozzle hole is too far from the axis of rotation, and if the nozzle hole goes to the circumferential end of the emitter, uneven discharge may occur due to the interfacial energy effect between the inner wall of the emitter 15 or the body 65 and the polymer solution. In order to minimize the interfacial energy effect between the inner wall surface of the emitter 15 or the body portion 65 and the polymer solution, the position of the nozzle is preferably spaced apart from the inner wall of the emitter 15 or the body portion 65.

In the case of the microporous nozzle described above, preferably, the micropores 70 are 0.7-1.0 mm in diameter, 4-6 mm away from the inner end of the body portion 65, and the thickness of the lower surface is It can be configured in the form of 4-16 mm. More preferably, the diameter of the micropores 70 is 0.8 mm, 3 mm from the inner end of the body portion 65, the thickness of the lower surface can be configured to 3 mm.

In addition, in the arrangement of the rotary emitter 15, the rotary emitter 15 may be arranged in various ways to increase production efficiency. That is, when the plurality of rotary emitters 15 are arranged in one row, a wide nanofiber film may be formed, and when the plurality of rotary emitters 15 are arranged in several rows, the formation of nanofibers may be faster. Since it can be made in time to increase the roller speed toward the recruitment electrode 20 has the advantage to increase the productivity through this. In an embodiment of such a double-row arrangement, the rotary emitter 15 has a two-column structure in which N rotary emitters are arranged at equal intervals in the first row and N-1 rotary types in the second row. The emitters may be configured such that the electrospinning nozzle module is arranged alternately with the emitters in the first row, or N-1 in the first row and N rotary emitters in the second row. The case where five rotary ejectors were staggered was shown. In this case, not only the spinning can be uniformly performed over the entire area, but also the process can be performed quickly.

In addition to the above-described arrangement of the rotary emitters 15 of the one-row to double-row method, instead of installing a plurality of rotary emitters 15, as shown in FIG. It is possible to inject the polymer solution while moving the rotary emitter to the left and right by configuring the electrostatic spinning device to further include a left and right transfer device and a driving unit for moving. Through this, not only the fabrication of the fiber layer of a large area is possible, but also the fiber layer or the fiber membrane of the required area can be manufactured by controlling the span of the moving stroke of the rotary emitter. Such a transfer mechanism can be applied to an electrostatic spinning device including a plurality of rotary emitters. To this end, it is possible to configure the electrostatic spinning device by utilizing a common left and right transfer mechanism.

In addition, the rotary emitter 15 shown in FIG. 2 can apply a combination of multiple emitters or its own left and right movement, as well as a combination of multiple emitters and its own left and right movement together. It is possible to spin the nanofibers 45 in a wide range in the form.

In addition to the above-described configuration, as shown in FIG. 2, an electrostatic spinning device as an embodiment of the electrostatic spinning device includes a storage container 40 for storing a polymer solution in addition to the above configuration, and a metering pump 35 for providing a certain amount of a polymer solution to the emitter. And a high voltage generator 50 having a high potential in the polymer solution, and a rotary roller near the recruitment electrode for continuous production of the fiber membrane.

In addition, in order for the nanofibers 45 to be uniformly and broadly formed, the electric field generated between the nozzle and the recruitment electrode 20 of the electrospinning apparatus needs to be more uniform and wider. The electrostatic emission value can be configured to further include an insulating layer as the discharge barrier 75 on the recruitment electrode therebetween. That is, according to the addition of the insulating layer, the electric field of the arc discharge type in the case of the absence of the insulating layer may be changed to the electric field of the barrier discharge type, thereby enabling uniform and wide radiation.

Of course, the insulating layer used in the present invention can use a conventional insulating material, in particular, urethane resin, heat-resistant synthetic resin, ceramic (ceramic), silicone (silicone), or polyimide (polyimide) resin. It is preferable to use glass fiber or the like, and preferably, urethane resin is used.

The insulating material is preferably coated on the surface of the recruitment electrode to a thickness of 0.1 to 5 mm, more preferably to a thickness of 1 to 3 mm.

The electrospun nanofibers 45 are collected on the grounded recruitment electrode 20 at the bottom, and the nanofibers 45 on the recruitment electrode 20 on which the nanofibers 45 are collected for fabrication of the fibrous membrane. May be rotated and collected through a roller, or heated or heated / compressed to form a wide film. In addition, in order to form a coating layer on a wide fiber, the wide fiber may pass through the roller under a rotary emitter at a constant speed, and a coating layer may be formed on the fiber by spinning the nanofibers 45 thereon. have.

According to the present invention, the radiation area is increased through the combination of centrifugal force and a plurality of rotary emitters according to rotation while utilizing the existing nozzle shape without expanding the radiation area of each nozzle, and forming a wider film having a wider width or wider width. It is possible to coat the fiber side of.

In addition, in the case of the manufacturing method of the present invention, the conventional method, by removing the hassle to go through a number of spinning operations while moving the emitter little by little for the production of a wide film, and can produce a wide film at once without repeated spinning operation Therefore, since the membrane is produced in one operation, there is no overlap part, so the thickness of the membrane is uniform, thickness control is easy, and production cost and fixed cost are very low, so it is suitable for mass production.

In addition, through the rectangular nozzle, it is possible to minimize the generation of arc even under the high turnover voltage between the nozzle and the recruitment electrode, and to stably discharge the polymer solution even when the nozzle is moved or rotated. As the radiation area is expanded and the arc generation rate is lowered, the turnover voltage can be increased and the separation distance can be increased accordingly, so that the radiation area can be further expanded to produce a wide nanofiber membrane. In addition to reducing the defective rate, production costs can be reduced.

In addition, it is possible to supply sufficient electric force to the polymer solution by the nozzle including the wire and maximize the repulsion force between the polymer solution and the nozzle to solve the problem of low fiber formation and difficult mass production due to the decrease of the electric force to help mass production. In addition to the wire, it is possible to apply a uniform thickness of the nanofibers through the linear micro-pores to produce an excellent nanofiber membrane.

In addition, by applying an electrostatic spinning device further comprising an insulating layer, the electric field generated between the nozzle and the recruiting electrode of the electrospinning device is made more uniform and wide, so that the spinning of the nanofiber is made uniform and wide.

 The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various modifications and changes made by those skilled in the art without departing from the spirit and scope of the present invention described in the claims below. Changes are also included within the scope of the invention.

1 is a system schematic diagram of an electrospinning process.

Figure 2 is a schematic diagram of an electrostatic spinning system which is one embodiment of a manufacturing apparatus for the present invention.

3 is a cross-sectional view of a right-angle needle nozzle which is one embodiment of a manufacturing apparatus according to the present invention.

Figure 4 is a rear view and a cross-sectional view of a needle-type nozzle of an embodiment of the manufacturing apparatus according to the present invention.

5 is a rear view and a cross-sectional view of a microporous nozzle which is one embodiment of a manufacturing apparatus according to the present invention.

6 is a rear view and a cross-sectional view of a wire-type electrostatic spinning nozzle which is one embodiment of a manufacturing apparatus according to the present invention.

7 is a rear view and a cross-sectional view of a wire-type electrostatic spinning nozzle which is another embodiment of the manufacturing apparatus according to the present invention.

8 is a perspective view of a double-row arrangement electrospinning nozzle module that is an embodiment of the manufacturing apparatus of the present invention.

9 is a perspective view of an electrostatic spinning nozzle module including a left and right moving mechanism that is an embodiment of the manufacturing apparatus according to the present invention.

Figure 10 is a schematic diagram of an electrostatic spinning system using a barrier discharge system, which is one embodiment of the manufacturing apparatus of the present invention.

Description of the main symbols in the drawings

10: needle nozzle 15: ejector

20: recruitment electrode 25: rotating device drive unit

30: rotating device 35: metering pump

40: solution storage container 45: nanofiber

50: high voltage generator 60: wire

65: body 70: micropores

75: discharge barrier

Claims (10)

a) supplying a polymer solution to at least two regularly arranged rotary emitters each of which comprises a plurality of electrospinning nozzle holes, each of which is driven by a rotating device and a drive unit thereof, and which is offset from the center of the rotating shaft, on each lower surface thereof; b) rotating the polymer solution eccentrically by the rotating device, and discharging the polymer solution through an electrostatic spinning nozzle to which a high voltage is applied; And, c) collecting the emitted fibers on a lower grounded recruitment electrode. The method of claim 1, The lower surface of the rotatable emitter is circular, the nozzle hole is a wide nanofiber manufacturing method, characterized in that consisting of 4 to 16 spaced apart from the end of the lower surface. The method of claim 1, And a shape of the nozzle end of the electrostatic spinning nozzle hole is perpendicular to the nozzle hole. The method of claim 1, The nozzle having the nozzle hole The upper portion is connected to the lower portion of the electrospinning emitter, the lower surface is clogged, characterized in that the nano-fiber manufacturing method comprising a constant volume of the body portion including a linearly arranged through the lower surface. The method of claim 1, The nozzle having the nozzle hole An upper portion connected to a lower portion of the electrospinning emitter, the lower portion of the body portion including a microhole arranged in a straight line through the lower surface is blocked; And, And a wire parallel to the array of micropores and spaced apart at a predetermined distance from the micropores, and both ends of which are fixed to the inner wall of the body portion. The method of claim 4, wherein The nozzle having the nozzle hole An upper portion connected to a lower portion of the electrospinning emitter, the lower portion of the body portion including a microhole arranged in a straight line through the lower surface is blocked; And, Parallel nanofiber arraying method is a wide nanofiber manufacturing method, characterized in that it comprises a wire fixed to the fixing projection protruding downward from the outer peripheral surface of the lower surface of the body portion and spaced apart a predetermined interval downward from the micropore . The method according to any one of claims 4 to 6, The micropore has a diameter of 0.7-1.0 mm, is 4-6 mm away from the inner end of the body portion, the thickness of the lower surface nano-fiber manufacturing method characterized in that 4-16 mm. The method of claim 1, The rotary emitters are arranged in a two-row structure with N rotary emitters arranged at equal intervals in the first row, and N-1 rotary emitters are arranged alternately with the emitters in the first row in the second row. Wide nanofiber manufacturing method. The method of claim 1, The method for producing a wide nanofiber, characterized in that further comprising the step of moving the rotary emitter from side to side in step b). The method of claim 1, The method of manufacturing a wide nanofiber, characterized in that the electrostatic radiation further comprises an insulating layer on the recruitment electrode during the electrostatic radiation of step b).