JP2012122151A - Apparatus for producing nanofiber and method for producing nanofiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for producing a nanofiber and a method for producing a nanofiber capable of mass-producing nanofiber nonwoven fabrics having a uniform air permeability.SOLUTION: An apparatus for producing a nanofiber 1 includes: a conveyance device 10 that conveys a long sheet W at a prescribed conveyance speed V; an electrospinning apparatus 20 that deposits nanofibers on the long sheet W being conveyed with the conveyance device 10; an air permeability measurement device 40 that measures air permeability of the long sheet W on which the nanofibers are deposited by the electrospinning apparatus 20; and a conveyance speed control device 50 that controls the conveyance speed V based on the air permeability P measured by the air permeability measurement device 40.

Description

  The present invention relates to a nanofiber manufacturing apparatus and a nanofiber manufacturing method.

  Conventionally, nanofibers having uniform physical properties can be produced by adjusting spinning conditions in the electrospinning process (for example, presence or absence of suspended matters in the spinning area, distance between nozzle block and collector, collector structure, etc.). A possible nanofiber production method is known (for example, see Patent Document 1).

  FIG. 12 is a diagram for explaining a nanofiber production apparatus 900 used in the nanofiber production method described in Patent Document 1. In FIG. 12, reference numeral 910 indicates a nozzle block, reference numeral 912 indicates a nozzle, reference numeral 920 indicates a blower, reference numeral 922 indicates a wind direction adjusting plate, reference numeral 924 indicates an edge member, and reference numeral 926 indicates an inhaler. Reference numeral 928 indicates a fan, and reference numeral 950 indicates a collector.

  The nanofiber manufacturing method described in Patent Document 1 volatilizes by forming an air flow in a spinning area defined by a blower 920, two edge members 924, and a suction device 926, as shown in FIG. The spinning conditions in the electrospinning process are adjusted by removing solvents and floating impurities.

  According to the nanofiber manufacturing method described in Patent Document 1, it is possible to manufacture nanofibers having uniform physical properties by adjusting the spinning conditions in the electrospinning process, and thus have a uniform air permeability. It is considered possible to produce nanofiber nonwoven fabrics.

JP 2008-274522 A

  However, even with the nanofiber manufacturing method described in Patent Document 1, in reality, it is not easy to keep the spinning conditions in the electrospinning process constant over a long period of time. Therefore, the nanofiber nonwoven fabric having uniform air permeability The fact is that it is difficult to mass-produce. Such a situation also applies to a nanofiber manufacturing method in which nanofibers are manufactured by a melt blow spinning device or other spinning device.

  Then, this invention is made | formed in view of the above situations, and provides the nanofiber manufacturing apparatus and nanofiber manufacturing method which can mass-produce the nanofiber nonwoven fabric which has uniform air permeability. With the goal.

[1] The nanofiber manufacturing apparatus of the present invention includes a transport device that transports a long sheet at a predetermined transport speed, a spinning device that deposits nanofibers on the long sheet transported by the transport device, and the spinning An air permeability measuring device that measures the air permeability of a long sheet on which nanofibers are deposited by an apparatus, and a transport speed control device that controls the transport speed based on the air permeability measured by the air permeability measuring device. It is characterized by that.

  According to the nanofiber manufacturing apparatus of the present invention, since the conveyance speed can be controlled based on the air permeability measured by the air permeability measuring apparatus, the spinning conditions fluctuate in the electrospinning process for a long time. Even if the degree of fluctuation varies, it is possible to keep the amount of fluctuation in air permeability within a specified range by appropriately controlling the conveyance speed accordingly, and as a result, mass production of nanofiber nonwoven fabric with uniform air permeability It becomes possible to do.

  For example, if the spinning conditions fluctuate in a direction that increases the air permeability during a long electrospinning process, the air permeability is reduced by increasing the amount of nanofibers deposited per unit area by slowing the conveying speed. As a result, the value of the air permeability can be kept within a predetermined range. Also, if the spinning conditions fluctuate in the direction of decreasing the air permeability during the long electrospinning process, increase the air permeability by increasing the conveying speed and reducing the amount of nanofibers deposited per unit area. As a result, the value of the air permeability can be kept within a predetermined range.

  In addition, it is possible to keep the value of the air permeability within a predetermined range by adjusting the spinning conditions such as “concentration of polymer solution” and “temperature and humidity in the spinning area”. Since it takes a certain time to adjust the spinning conditions according to the variation in the air permeability, it is difficult to produce a nanofiber nonwoven fabric having a uniform air permeability along the longitudinal direction with high productivity.

  In addition, by adjusting spinning conditions such as “interval between nozzle and collector” and “voltage applied between nozzle and collector”, the value of air permeability can be kept within a predetermined range. In these cases, the physical properties of the nanofiber such as the diameter of the nanofiber and the density of the nanofiber layer vary, and it is difficult to produce a nanofiber nonwoven fabric having uniform physical properties.

  On the other hand, according to the nanofiber manufacturing apparatus of the present invention, the nanofiber nonwoven fabric having a uniform air permeability can be obtained by a simple method of controlling the conveyance speed based on the air permeability measured by the air permeability measuring apparatus. Since mass production is possible, there is no problem that it takes a certain amount of time to adjust spinning conditions according to fluctuations in air permeability, and there is no problem of nanofibers such as nanofiber diameter and nanofiber layer density. There is no problem that the physical properties fluctuate.

  In the present invention, the air permeability of the long sheet on which the nanofibers are deposited is a case where the air permeability is measured in a state where the nanofiber layer deposited on the long sheet and the long sheet are laminated. The air permeability in The nanofiber nonwoven fabric refers to a long sheet on which nanofibers are deposited. The nanofiber nonwoven fabric may be used as a product as it is, or a long sheet may be removed from the nanofiber nonwoven fabric to produce a “nonwoven fabric consisting of only a nanofiber layer”, which may be used as a product. The “nanofiber” refers to a fiber made of a polymer and having an average diameter of several nm to several thousand nm. The “polymer solution” refers to a solution in which a polymer is dissolved in a solvent.

[2] In the nanofiber manufacturing apparatus of the present invention, the transport speed control device controls the transport speed based on a deviation amount between the air permeability measured by the air permeability measuring device and a predetermined target air permeability. It is preferable to do.

  According to the nanofiber manufacturing apparatus of the present invention, for example, when the deviation amount is large, the control amount (change amount from the initial value) of the conveyance speed is increased, and when the deviation amount is small, the conveyance speed is increased. Therefore, it is possible to perform control such as reducing the control amount (change amount from the initial value), and accordingly it is possible to appropriately control the conveyance speed in accordance with the degree of variation in the air permeability.

  Further, according to the nanofiber manufacturing apparatus of the present invention, for example, when the deviation amount is less than a predetermined value, without changing the transport speed from the initial value, when the deviation amount is a predetermined value or more, Since it is possible to perform control such as changing the transport speed from the initial value, it is possible to simplify the control of the transport speed by the transport speed control device.

[3] In the nanofiber manufacturing apparatus of the present invention, it is preferable that the transport speed control device controls the transport speed in consideration of a time change rate of the deviation amount.

  In this way, by considering the “time change rate of deviation amount”, it is possible to more appropriately control the conveyance speed as compared with the case where the conveyance speed is controlled based only on the deviation amount. For example, when the spinning conditions change suddenly, the time change rate of the deviation amount is large, so the control amount (change amount from the initial value) of the conveyance speed is increased to match it. Further, when the variation amount of the spinning condition is small, the time change rate of the deviation amount is small, so the control amount of the conveyance speed (change amount from the initial value) is reduced to match it.

[4] In the nanofiber manufacturing apparatus of the present invention, the air permeability measuring device includes an air permeability measuring unit that measures the air permeability of the long sheet, and the air permeability measuring unit in the width direction of the long sheet. It is preferable to include a drive unit that reciprocates along a predetermined cycle along the drive unit.

  With such a configuration, the air permeability can be measured over a wide area in the width direction of the long sheet, and the conveyance speed can be more appropriately controlled.

[5] In the nanofiber manufacturing apparatus of the present invention, the transport speed control device sets the air permeability measured by the air permeability measuring unit to the predetermined period or a time corresponding to n times the period (however, n Is preferably controlled based on an average air permeability obtained by averaging with a natural number.

  By adopting such a configuration, even when the air permeability is distributed in the width direction of the long sheet, the transport speed is controlled more appropriately by controlling the transport speed based on the average air permeability. It becomes possible to do.

[6] In the nanofiber manufacturing apparatus according to the present invention, the air permeability measuring device is disposed at a plurality of positions in the width direction of the long sheet as an air permeability measuring unit that measures the air permeability of the long sheet. It is preferable to provide a plurality of air permeability measuring units.

  Even with such a configuration, the air permeability can be measured over a wide area in the width direction of the long sheet, as in the case of the nanofiber manufacturing apparatus according to [4] above, and transported more appropriately. The speed can be controlled.

[7] In the nanofiber manufacturing apparatus of the present invention, the transport speed control device controls the transport speed based on an average air permeability obtained by averaging the air permeability measured by the plurality of air permeability measuring units. It is preferable to do.

  By adopting such a configuration, as in the case of the nanofiber manufacturing apparatus according to [5] above, even if there is a distribution in the air permeability in the width direction of the long sheet, it is based on the average air permeability. By controlling the transport speed, the transport speed can be controlled more appropriately.

[8] The nanofiber manufacturing apparatus of the present invention further includes a heating device that is disposed between the spinning device and the air permeability measuring device and that heats the long sheet on which the nanofibers are deposited. preferable.

  By adopting such a configuration, it is possible to completely evaporate the solvent that may remain in the nanofiber layer, and thus it is possible to manufacture a high-quality nanofiber nonwoven fabric with extremely little residual solvent. Further, since the air permeability can be measured in a state where the solvent is completely evaporated, the air permeability can be accurately measured.

[9] In the nanofiber manufacturing apparatus of the present invention, it is preferable that the spinning device includes a plurality of spinning devices arranged in series along a predetermined transport direction in which the long sheet is transported.

  By adopting such a configuration, it becomes possible to deposit nanofibers one after another on a long sheet in each of a plurality of spinning apparatuses, so that a nanofiber nonwoven fabric having a uniform air permeability can be further increased in productivity. Enables mass production. In addition, even when mass-producing nanofiber nonwoven fabrics in which various types of nanofibers are sequentially deposited on a long sheet, it is possible to mass-produce nanofiber nonwoven fabrics having uniform air permeability with even higher productivity. Become. In addition, even in a nanofiber manufacturing apparatus including a plurality of spinning devices, a nanofiber nonwoven fabric having uniform air permeability can be obtained by controlling the conveying speed instead of adjusting the spinning conditions in each of the plurality of spinning devices. Can be mass-produced.

[10] In the nanofiber manufacturing apparatus of the present invention, the spinning device is preferably an electrospinning device.

  By adopting such a configuration, even in a nanofiber manufacturing apparatus including an electrospinning apparatus capable of manufacturing nanofibers having an extremely thin diameter (several nm to several thousand nm) as a spinning apparatus, the nanofiber manufacturing apparatus has a uniform air permeability. It becomes possible to mass-produce nanofiber nonwoven fabrics.

[11] The nanofiber manufacturing method of the present invention measures the air permeability of the long sheet on which the nanofibers are deposited, while depositing nanofibers on the long sheet that is being transported at a predetermined transport speed, The conveying speed of the long sheet is controlled based on the air permeability of the long sheet.

  According to the nanofiber manufacturing method of the present invention, the air permeability of a long sheet on which nanofibers are deposited is measured, and the conveyance speed of the long sheet is controlled based on the air permeability. Even if the spinning conditions fluctuate in the spinning process and the air permeability changes, it is possible to keep the air permeability fluctuation amount within a predetermined range by appropriately controlling the conveyance speed accordingly, and as a result It becomes possible to mass-produce nanofiber nonwoven fabric having air permeability.

  According to the nanofiber production apparatus or nanofiber production method of the present invention, high-function / high-sensitivity textiles and other clothing items, health care, skin care and other beauty-related products, wiping cloth, filters and other industrial materials, secondary battery separators, Capacitor separators, various catalyst supports, electronic and mechanical materials such as various sensor materials, regenerative medical materials, biomedical materials, medical MEMS materials, medical materials such as biosensor materials, and other nanofibers that can be used in a wide range of applications Can be manufactured.

It is a figure shown in order to demonstrate the nanofiber manufacturing apparatus 1 which concerns on embodiment. It is a principal part enlarged view of the electrospinning apparatus 20 in embodiment. It is a block diagram of the principal part of the nanofiber manufacturing apparatus 1 which concerns on Embodiment 1. FIG. It is a flowchart shown in order to demonstrate a nanofiber manufacturing method. It is a figure shown in order to demonstrate the motion of the air permeability measurement part 41. FIG. It is a graph showing the time change of air permeability P, average air permeability <P>, and conveyance speed V. 10 is a graph showing temporal changes in air permeability P, average air permeability <P>, and conveyance speed V in Modification 1. It is a flowchart shown in order to demonstrate the nanofiber manufacturing method in the modification 2. 12 is a graph showing temporal changes in air permeability P, average air permeability <P>, and conveyance speed V in Modification 2. It is a figure which shows the structure of the air permeability measurement part 41a in Embodiment 2. FIG. It is a principal part enlarged view of the electrospinning apparatus 20a. It is a figure shown in order to demonstrate the nanofiber manufacturing apparatus 900 used for the nanofiber manufacturing method described in patent document 1. FIG.

  Hereinafter, the nanofiber manufacturing apparatus and nanofiber manufacturing method of the present invention will be described based on the embodiments shown in the drawings.

[Embodiment 1]
1. Configuration of nanofiber manufacturing apparatus 1 according to Embodiment 1 Fig. 1 is a diagram illustrating the nanofiber manufacturing apparatus 1 according to the embodiment. FIG. 1A is a front view of the nanofiber manufacturing apparatus 1, and FIG. 1B is a plan view of the nanofiber manufacturing apparatus 1. In FIG. 1, the polymer solution supply unit and the polymer solution recovery unit are not shown. Further, in FIG. 1A, some members are shown in an enlarged view of a main part. FIG. 2 is an enlarged view of a main part of the electrospinning apparatus 20.

  As shown in FIGS. 1 and 2, the nanofiber manufacturing apparatus 1 according to the first embodiment includes a conveyance device 10 that conveys a long sheet W at a predetermined conveyance speed V, and a long length that is conveyed by the conveyance device 10. Measured by an electrospinning device 20 that deposits nanofibers on the sheet W, an air permeability measuring device 40 that measures the air permeability P of the long sheet W on which nanofibers are deposited by the electrospinning device 20, and an air permeability measuring device 40. A transport speed control device 50 that controls the transport speed V based on the air permeability P.

  The nanofiber manufacturing apparatus 1 according to Embodiment 1 includes four electrospinning apparatuses 20 arranged in series along a predetermined conveyance direction a along which a long sheet W is conveyed as an electrospinning apparatus.

  The nanofiber manufacturing apparatus 1 according to the first embodiment is arranged between the electrospinning apparatus 20 and the air permeability measurement apparatus 40, and includes a heating apparatus 30 that heats the long sheet W on which nanofibers are deposited, and a “conveying apparatus”. 10, main control device 60 for controlling the operation of the electrospinning device 20, the heating device 30, the air permeability measuring device 40, the conveyance speed control device 50, the VOC processing device 70, the polymer supply device and the polymer recovery device described later, And a VOC processing device 70 that burns and removes volatile components generated when nanofibers are deposited on the length sheet W.

  The conveying device 10 includes a feeding roller 11 that feeds out the long sheet W, a winding roller 12 that winds up the long sheet W, auxiliary rollers 13 and 18 and a driving roller 14 that are positioned between the feeding roller 11 and the winding roller 12. , 15, 16, and 17 are provided. The feeding roller 11, the winding roller 12, and the driving rollers 14, 15, 16, and 17 are configured to be rotationally driven by a driving motor (not shown).

  As shown in FIG. 2, the electrospinning apparatus 20 is attached to the casing 100 via an insulating member 152, and is provided with a collector 150 positioned on one side of the long sheet W and the other side of the long sheet W. A nozzle block 110 having a plurality of nozzles which are located on the side facing the collector 150 and inject a polymer solution supplied from a polymer solution supply unit (not shown) toward the long sheet W, and the collector 150 and the nozzle block 110 A power supply device 160 that applies a high voltage (for example, 10 kV to 80 kV), an electrospinning chamber 102 that defines a predetermined space covering the collector 150 and the nozzle block 110, and a long sheet W is conveyed. And an auxiliary belt device 170 for assisting. The positive electrode of the power supply device 160 is connected to the collector 150, and the negative electrode of the power supply device 160 is connected to the nozzle block 110 via the housing 100.

  As shown in FIG. 2, the nozzle block 110 has a plurality of upward nozzles that discharge the polymer solution upward from the discharge ports as a plurality of nozzles. The nanofiber manufacturing apparatus 1 discharges the polymer solution from the discharge ports of the plurality of upward nozzles while overflowing the polymer solution from the discharge ports of the plurality of upward nozzles, and electrospins the nanofibers. The polymer solution overflowed from the discharge port is collected and can be reused as a raw material for nanofibers. The plurality of upward nozzles 112 are arranged at a pitch of 1.5 cm to 6.0 cm, for example. The number of the plurality of upward nozzles 112 is, for example, 36 (6 × 6 when arranged in the same vertical and horizontal direction) to 21904 (148 × 148 when arranged in the same vertical and horizontal number). In addition, the nanofiber manufacturing apparatus of the present invention can use nozzle blocks having various sizes and various shapes. For example, the nozzle block 110 has a side of 0.5 m to 3 m when viewed from above. It has a size and shape that can be seen as a rectangle (including a square).

  As shown in FIG. 2, the auxiliary belt device 170 includes an auxiliary belt 172 that rotates in synchronization with the conveyance speed of the long sheet W, and five auxiliary belt rollers 174 that assist the rotation of the auxiliary belt 172. Of the five auxiliary belt rollers 174, one or more auxiliary belt rollers 174 are drive rollers, and the remaining auxiliary belt rollers are driven rollers. Since the auxiliary belt 172 is disposed between the collector 150 and the long sheet W, the long sheet W is smoothly conveyed without being attracted to the collector 150 to which a positive high voltage is applied. become.

  The heating device 30 is disposed between the electrospinning device 20 and the air permeability measuring device 40 and heats the long sheet W on which nanofibers are deposited. Although heating temperature changes with kinds of elongate sheet W and nanofiber, elongate sheet W can be heated to the temperature of 50 to 300 degreeC, for example.

  As shown in FIG. 3, the air permeability measuring device 40 has an air permeability measuring unit 41 that measures the air permeability P of the long sheet W, and the air permeability measuring unit 41 has a predetermined length along the width direction of the long sheet W. A drive unit 43 that reciprocates at a period T, and a control unit 44 that controls the operations of the drive unit 43 and the air permeability measurement unit 41 and that receives and processes the measurement results from the air permeability measurement unit 41 are provided. The drive unit 43 and the control unit 44 are disposed in the main body unit 42. As the air permeability measuring device 40, a general air permeability measuring device can be used.

  The air permeability measuring device 40 can also transmit the measured value of the air permeability P as it is to the transport speed control device 50, and the measured air permeability P corresponds to a predetermined period T or n times the period T. It is also possible to transmit the value of average air permeability <P> obtained by averaging over the time (where n is a natural number) to the conveyance speed control device 50.

  The conveyance speed control device 50 controls the conveyance speed V of the long sheet W conveyed by the conveyance device 10 based on the air permeability P or the average air permeability <P> measured by the air permeability measurement unit 40. For example, when the spinning conditions fluctuate in the direction in which the air permeability P increases in the long-time electrospinning process, the air permeability can be reduced by increasing the amount of nanofibers deposited per unit area by slowing the conveying speed V. Make it smaller. On the other hand, if the spinning conditions fluctuate in the direction of decreasing the air permeability during the long-time electrospinning process, the air permeability is increased by increasing the conveyance speed and reducing the amount of nanofibers deposited per unit area. . The conveyance speed V can be controlled by controlling the rotation speed of the drive rollers 14, 15, 16, and 17.

  The VOC processing device 70 burns and removes volatile components generated when nanofibers are deposited on the long sheet.

  The main controller 60 controls operations of the transport device 10, the electrospinning device 20, the heating device 30, the air permeability measuring device 40, the transport speed control device 50, the VOC processing device 70, the polymer supply device, and the polymer recovery device.

2. Nanofiber manufacturing method using nanofiber manufacturing apparatus 1 according to Embodiment 1 Hereinafter, a method of manufacturing a nanofiber nonwoven fabric using nanofiber manufacturing apparatus 1 according to Embodiment 1 configured as described above (Embodiment 1) Will be described.

  FIG. 4 is a flowchart for explaining the nanofiber manufacturing method according to the first embodiment. FIG. 5 is a diagram for explaining the movement of the air permeability measuring unit 41. FIG. 5A to FIG. 5F are process diagrams. In FIG. 5, a curve shown in a sinusoidal shape is a trajectory connecting portions where the air permeability measurement unit 41 has measured the air permeability on the long sheet W.

FIG. 6 is a graph showing temporal changes in the air permeability P, the average air permeability <P>, and the conveyance speed V. 6A is a graph showing the time change of the air permeability P, FIG. 6B is a graph showing the time change of the average air permeability <P>, and FIG. It is a graph showing a change. 6 (a) and 6 in (b), reference numeral P ₀ indicates the target air permeability, reference numeral P _H denotes the upper limit of the air permeability acceptable, reference numeral P _L denotes the lower limit of the air permeability allowed . In FIG. 6C, the symbol V ₀ indicates the initial value of the conveyance speed.

  As shown in FIG. 4, the nanofiber manufacturing method according to Embodiment 1 includes “long sheet conveyance / electrospinning”, “air permeability measurement”, “average air permeability calculation”, and “deviation amount ΔP calculation” “conveyance”. Each step of “speed control” is included.

1. Long sheet conveyance / electrospinning (S10)
The long sheet W is set on the conveying device 10, and then the long sheet W is conveyed at a predetermined conveying speed V from the feeding roller 11 toward the take-up roller 12, and the long sheet W is used in each electrospinning device 20. The nanofibers are sequentially deposited on the substrate. Thereafter, the heating device 30 heats the long sheet W on which the nanofibers are deposited. Thereby, the nanofiber nonwoven fabric which consists of a elongate sheet | seat with which nanofiber was accumulated is manufactured.

  At this time, according to the following procedure, the air permeability P of the long sheet W on which nanofibers are deposited by the electrospinning apparatus 20 is measured, and the conveyance speed V is based on the air permeability P measured by the air permeability measuring apparatus 40. To control. In the first embodiment, as shown in FIGS. 6A to 6C, the conveyance speed is not controlled for the period before the time t has elapsed, and the conveyance speed is not used for the period after the time t has elapsed. It is going to be controlled. The same applies to Modifications 1 and 2 below.

2. Air permeability measurement (S12)
First, as shown in FIG. 5A to FIG. 5F, the air permeability measuring unit 41 is moved back and forth along the width direction of the long sheet W at a predetermined period T (for example, 1 second). The air permeability of the measure sheet W is measured. The measurement of the air permeability by the air permeability measuring unit 41 is performed, for example, every 10 ms. As a result, a graph as shown in FIG.

3. Average air permeability calculation (S14)
Next, the average air permeability <P> is calculated by averaging the air permeability P measured by the air permeability measuring unit 41 with a predetermined period T (for example, 1 second). As a result, a graph as shown in FIG. 6B is obtained.

4). Deviation amount ΔP calculation (S16)
Next, a deviation amount ΔP between the average air permeability <P> and a predetermined target air permeability P ₀ is calculated.

5. Conveyance speed control (S18-S24)
Next, the conveyance speed V is controlled based on the deviation amount ΔP.
For example, when the spinning conditions fluctuate in the direction in which the air permeability P increases in the long-time electrospinning process (when the deviation amount ΔP is positive), the transport speed V is decreased to deposit nanofibers per unit area. Decrease the air permeability by increasing the amount. On the other hand, when the spinning conditions fluctuate in a direction in which the air permeability decreases in the long-time electrospinning process (when the deviation amount ΔP is negative), the conveyance speed V is increased to increase the nanofiber deposition amount per unit area. To increase the air permeability (see FIG. 6C). Accordingly, after the time t has elapsed, the air permeability P gradually converges to a predetermined target air permeability P ₀ .

  The spinning conditions in the nanofiber manufacturing method according to Embodiment 1 will be exemplified below.

  As the long sheet, nonwoven fabrics, woven fabrics, knitted fabrics and the like made of various materials can be used. For example, a long sheet having a thickness of 5 μm to 500 μm can be used. The length of the long sheet can be, for example, 10 m to 10 km.

  Examples of the polymer used as a raw material for the nanofiber include polylactic acid (PLA), polypropylene (PP), polyvinyl acetate (PVAc), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), Polyamide (PA), polyurethane (PUR), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyetherimide (PEI), polycaprolactone (PCL), polylactic glycolic acid (PLGA), silk, cellulose, chitosan, etc. Can be used.

  Examples of the solvent used in the polymer solution include dichloromethane, dimethylformamide, dimethyl sulfoxide, methyl ethyl ketone, chloroform, acetone, water, formic acid, acetic acid, cyclohexane, and THF. A plurality of types of solvents may be mixed and used. The polymer solution may contain an additive such as a conductivity improver.

Air permeability P of the nano-fiber nonwoven fabric manufactured can be set to, for example, ^{0.15cm 3 / cm 2 / s~200cm 3} / cm 2 / s. The conveyance speed V can be set to 0.2 m / min to 100 m / min, for example. The voltage applied to the nozzle, collector 150 and nozzle block 110 can be set to 10 kV to 80 kV, and is preferably set to around 50 kV.

  The temperature of the spinning zone can be set at 25 ° C., for example. The humidity of the spinning area can be set to 30%, for example.

3. Effects of nanofiber manufacturing apparatus 1 according to Embodiment 1

  According to the nanofiber manufacturing apparatus 1 according to the first embodiment, the measurement is performed by the air permeability measuring device 40 that measures the air permeability P of the long sheet W on which the nanofibers are deposited by the spinning device 20 and the air permeability measuring device 40. Since the conveyance speed control device 50 that controls the conveyance speed V based on the air permeability P is provided, the conveyance speed can be controlled based on the air permeability measured by the air permeability measurement device. For this reason, even if the spinning conditions fluctuate and the air permeability fluctuates in the long-term electrospinning process, it is possible to keep the air flow fluctuation amount within a predetermined range by appropriately controlling the conveying speed accordingly. As a result, the nanofiber nonwoven fabric having uniform air permeability can be mass-produced.

Further, according to the nanofiber manufacturing apparatus according to the first embodiment, the conveyance speed V is controlled based on the deviation ΔP between the air permeability P measured by the air permeability measuring device 40 and the predetermined target air permeability P _0. Therefore, for example, when the shift amount ΔP is large, it increases the control amount of the conveyance speed V (the amount of change from the initial value V _0), if the shift amount ΔP is small, controlled amount of the transport velocity V it is possible to control such that the smaller (initial value change amount from V _0), it is possible to properly control the conveying speed according to the degree of variation in the air permeability.

  Moreover, according to the nanofiber manufacturing apparatus 1 according to the first embodiment, the air permeability measuring device 40 measures the air permeability P of the long sheet W, and the air permeability measuring unit 41 includes the long sheet W. Drive unit 43 that reciprocates at a predetermined period T along the width direction of the sheet W, the air permeability can be measured over a wide area in the width direction of the long sheet W, and the conveyance speed can be controlled more appropriately. It becomes possible to do.

  Moreover, according to the nanofiber manufacturing apparatus 1 which concerns on Embodiment 1, the conveyance speed control apparatus 50 is equivalent to the air permeability P measured by the air permeability measurement part 40 for the predetermined period T or n times the said period T. Since the conveyance speed V can be controlled based on the average air permeability <P> obtained by averaging over time (where n is a natural number), the air permeability P is distributed in the width direction of the long sheet W. Even in some cases, the conveyance speed can be controlled more appropriately by controlling the conveyance speed V based on the average air permeability <P>.

  Moreover, according to the nanofiber manufacturing apparatus 1 which concerns on Embodiment 1, the heating apparatus 30 which is arrange | positioned between the electrospinning apparatus 20 and the air permeability measuring apparatus 40, and heats the elongate sheet W on which the nanofiber was deposited is provided. Furthermore, since it is possible to completely evaporate the solvent that may remain in the nanofiber layer, it is possible to manufacture a high-quality nanofiber nonwoven fabric with extremely little residual solvent. In addition, since the air permeability P can be measured in a state where the solvent is completely evaporated, the air permeability can be accurately measured.

  Moreover, according to the nanofiber manufacturing apparatus 1 which concerns on Embodiment 1, as the electrospinning apparatus, the several electrospinning apparatus 20 arrange | positioned in series along the predetermined conveyance direction a along which the elongate sheet W is conveyed is included. Therefore, nanofibers can be deposited one after another on the long sheet W in each of the plurality of electrospinning apparatuses 20, and the nanofiber nonwoven fabric having uniform air permeability can be mass-produced with higher productivity. Is possible. In addition, when mass-producing nanofiber nonwoven fabrics in which various types of nanofibers are sequentially deposited on the long sheet W, it is possible to mass-produce nanofiber nonwoven fabrics having uniform air permeability with higher productivity. It becomes. Further, even in a nanofiber manufacturing apparatus including a plurality of electrospinning apparatuses 20, uniform air permeability can be obtained only by controlling the conveying speed V instead of adjusting the spinning conditions in each of the plurality of electrospinning apparatuses 20. It becomes possible to mass-produce nanofiber nonwoven fabrics having

  Moreover, according to the nanofiber manufacturing apparatus 1 which concerns on Embodiment 1, it is a nanofiber manufacturing apparatus provided with the electrospinning apparatus which can manufacture the nanofiber which has a very thin diameter (several nm-several thousand nm) as a spinning apparatus. However, it is possible to mass-produce nanofiber nonwoven fabrics having uniform air permeability.

  According to the nanofiber manufacturing method according to the first embodiment, the nanofibers are deposited on the long sheet W being conveyed at the predetermined conveyance speed V, and the air permeability P of the long sheet W on which the nanofibers are deposited is measured. However, since the conveyance speed V of the long sheet W is controlled based on the air permeability P of the long sheet W, even if the spinning conditions fluctuate in the electrospinning process for a long time, the air permeability varies. By appropriately controlling the conveying speed accordingly, it becomes possible to keep the variation amount of the air permeability within a predetermined range, and as a result, it becomes possible to mass-produce nanofiber nonwoven fabrics having uniform air permeability. .

[Modification 1]
FIG. 7 is a graph showing changes over time in the air permeability P, the average air permeability <P>, and the conveyance speed V in the first modification. FIG. 7A is a graph showing the time change of the air permeability P, FIG. 7B is a graph showing the time change of the average air permeability <P>, and FIG. It is a graph showing a change. 7 (a) and 7 in (b), reference numeral P ₀ indicates the target air permeability, reference numeral P _H denotes the upper limit of the air permeability acceptable, reference numeral P _L denotes the lower limit of the air permeability allowed . In FIG. 7C, reference numeral V ₀ indicates an initial value of the conveyance speed.

In the first modification, as can be seen from FIG. 7C, the transport speed V is controlled in steps. Thus, even when the conveyance speed V is controlled stepwise, as shown in FIGS. 7A and 7B, the air permeability P and the average airflow are the same as in the first embodiment. degrees and <P> it is possible to converge to the target air permeability P _0.

[Modification 2]
FIG. 8 is a flowchart for explaining the nanofiber manufacturing method according to the second modification. FIG. 9 is a graph showing temporal changes in the air permeability P, the average air permeability <P>, and the conveyance speed V in Modification 2. 9A is a graph showing the time change of the air permeability P, FIG. 9B is a graph showing the time change of the average air permeability <P>, and FIG. 9C is the time of the conveyance speed V. It is a graph showing a change. 9 (a) and 9 in (b), reference numeral P ₀ indicates the target air permeability, reference numeral P _H denotes the upper limit of the air permeability acceptable, reference numeral P _L represents the lower limit of the air permeability allowed , P _H1 indicates the upper control start air permeability, and P _L1 indicates the lower control start air permeability. In FIG. 9C, the symbol V ₀ indicates the initial value of the conveyance speed.

In the nanofiber manufacturing method according to the modified example 2, as can be seen from FIGS. 8 and 9, when the average air permeability <P> is higher than the upper control start air permeability _PH1 , or the lower control start air permeability. if it becomes lower than P _L1, controls the conveying speed V (varying from the initial value) is set to be. Even in the case of performing such control, as shown in FIGS. 9A and 9B, the air permeability P and the average air permeability <P> are set to the target ventilation as in the case of the first embodiment. It is possible to converge to the degree P ₀ . In addition, according to the nanofiber manufacturing method according to the modified example 2, it is possible to reduce the frequency of changing the conveyance speed V.

[Embodiment 2]
FIG. 10 is a diagram illustrating a configuration of the air permeability measurement unit 41a according to the second embodiment. FIG. 10A is a diagram illustrating the configuration of the air permeability measuring unit 41a, and FIG. 10B is a diagram additionally adding a trajectory connecting portions where the air permeability measuring unit 41 measures the air permeability on the long sheet W. Is.

  The nanofiber manufacturing method 2 (not shown) according to the second embodiment basically has the same configuration as that of the nanofiber manufacturing apparatus 1 according to the first embodiment, but the configuration of the air permeability measuring device is the same as that of the first embodiment. This is different from the case of the nanofiber manufacturing apparatus 1. That is, in the nanofiber manufacturing apparatus 2 according to the second embodiment, the air permeability measuring device 40a (not shown) serves as an air permeability measuring unit that measures the air permeability P of the long sheet W as shown in FIG. The three air permeability measuring units 41a are provided at a plurality of positions in the width direction of the long sheet W (a central portion, a left end portion, and a right end portion in the width direction of the long sheet).

  As described above, the nanofiber manufacturing apparatus 2 according to the second embodiment is different from the nanofiber manufacturing apparatus 1 according to the first embodiment in the configuration of the air permeability measurement apparatus, but the nanofibers are deposited by the electrospinning apparatus 20. Since the air permeability measuring device 40a for measuring the air permeability P of the long sheet W and the conveyance speed control device 50 for controlling the conveyance speed V based on the air permeability P measured by the air permeability measuring device 40a are provided. The conveyance speed can be controlled based on the air permeability measured by the degree measuring device. For this reason, similarly to the case of the nanofiber manufacturing apparatus 1 according to the first embodiment, even if the spinning conditions fluctuate and the air permeability fluctuates in the electrospinning process for a long time, the conveyance speed is appropriately controlled accordingly. This makes it possible to keep the amount of variation in air permeability within a predetermined range, and as a result, it is possible to mass-produce nanofiber nonwoven fabrics having uniform air permeability.

  Moreover, according to the nanofiber manufacturing apparatus 2 which concerns on Embodiment 2, the air permeability measuring apparatus 40a is a several air permeability measuring part arrange | positioned in the several position in the width direction of the elongate sheet W as an air permeability measuring part. Since 41a is provided, it is possible to measure the air permeability over a wide area in the width direction of the long sheet and control the conveyance speed more appropriately, as in the case of the nanofiber manufacturing apparatus 1 according to the first embodiment. Is possible.

  Moreover, according to the nanofiber manufacturing apparatus 2 which concerns on Embodiment 2, the conveyance speed control apparatus 50 is set to the average air permeability <P> obtained by averaging the air permeability P measured by the some air permeability measuring part 41a. Since it is supposed to control the conveyance speed V based on the same as in the case of the nanofiber manufacturing apparatus 1 according to Embodiment 1, even when there is a distribution in the air permeability P in the width direction of the long sheet W, By controlling the conveyance speed V based on the average air permeability <P>, the conveyance speed can be controlled more appropriately.

  In addition, since the nanofiber manufacturing apparatus 2 which concerns on Embodiment 2 has the structure similar to the case of the nanofiber manufacturing apparatus 1 which concerns on Embodiment 1 except the structure of an air permeability measurement apparatus, the nanofiber manufacturing which concerns on Embodiment 1 It has a corresponding effect among the effects which the apparatus 1 has.

  As mentioned above, although this invention was demonstrated based on said embodiment, this invention is not limited to said embodiment. The present invention can be implemented in various modes without departing from the spirit thereof, and for example, the following modifications are possible.

(1) In each of the above embodiments, the nanofiber manufacturing apparatus of the present invention has been described by taking the nanofiber manufacturing apparatus including four electrospinning apparatuses as the electrospinning apparatus. However, the present invention is limited to this. is not. For example, the present invention can also be applied to a nanofiber manufacturing apparatus including 1 to 3 or 5 or more electrospinning apparatuses. Further, the present invention can be applied to a nanofiber manufacturing apparatus using a melt blow spinning apparatus or the like instead of the electrospinning apparatus. In addition, the nanofiber production apparatus of the present invention is a sheet in which a non-woven fabric is produced on a long sheet using a melt blow spinning apparatus, a spunbond spinning apparatus, a needle punch spinning apparatus and other spinning apparatuses, and nanofibers are further deposited. It can also be suitably used when the conveyance speed is controlled based on the air permeability.

(2) In each of the above embodiments, the nanofiber production apparatus of the present invention has been described using an upward electrospinning apparatus having an upward nozzle, but the present invention is not limited to this. For example, the present invention can be applied to a nanofiber manufacturing apparatus including a downward electrospinning apparatus having a downward nozzle or a lateral electrospinning apparatus having a lateral nozzle.

(3) In each of the above embodiments, the nanofiber manufacturing apparatus of the present invention is described using an electrospinning apparatus in which the positive electrode of the power supply device 160 is connected to the collector 150 and the negative electrode of the power supply device 160 is connected to the nozzle block 110. However, the present invention is not limited to this. For example, the present invention can be applied to a nanofiber manufacturing apparatus including an electrospinning apparatus in which a positive electrode of a power supply device is connected to a nozzle and a negative electrode of the power supply device is connected to a collector.

(4) When the nanofiber manufacturing apparatus of the present invention mass-produces nanofiber nonwoven fabric having uniform air permeability by depositing nanofibers having uniform air permeability on a long sheet having uniform air permeability Of course, it is also suitable for mass production of nanofiber nonwoven fabrics having uniform air permeability as a whole by depositing nanofibers having air permeability corresponding to long sheets having air permeability that is not so uniform. Can do.

(5) In the above embodiment, the present invention has been described using a nanofiber manufacturing apparatus in which one nozzle block is disposed in one electrospinning apparatus, but the present invention is not limited to this. It is a principal part enlarged view of the electrospinning apparatus 20a. For example, as shown in FIG. 11, the present invention can be applied to a nanofiber manufacturing apparatus in which two nozzle blocks 110a1 and 110a2 are arranged in one electrospinning apparatus 20a, and there are two or more nozzle blocks. The present invention can also be applied to the arranged nanofiber manufacturing apparatus.

  In this case, the nozzle arrangement pitch can be made the same for all nozzle blocks, or the nozzle arrangement pitch can be made different for each nozzle block. Moreover, the height position of a nozzle block can also be made the same by all the nozzle blocks, and the height position of a nozzle block can also be varied by each nozzle block.

(6) The nanofiber manufacturing apparatus of the present invention may include a mechanism for reciprocating the nozzle block at a predetermined reciprocating cycle along the width direction of the long sheet. By performing electrospinning while reciprocating the nozzle block at a predetermined reciprocating period using this mechanism, the amount of polymer fibers deposited along the width direction of the long sheet can be made uniform. In this case, the reciprocating period and the reciprocating distance of the nozzle block may be controllable independently for each electrospinning apparatus or for each nozzle block. By setting it as such a structure, all the nozzle blocks can also be reciprocated with the same period, and each nozzle block can also be reciprocated with a different period. Further, the reciprocating distance of the reciprocating motion can be made the same for all the nozzle blocks, and the reciprocating distance of the reciprocating motion can be made different for each nozzle block.

DESCRIPTION OF SYMBOLS 1 ... Nano fiber manufacturing apparatus, 10 ... Conveyance apparatus, 11 ... Feeding roller, 12 ... Winding roller, 13, 18 ... Auxiliary roller, 14, 15, 16, 17 ... Drive roller, 20, 20a ... Electrospinning apparatus, 30 ... heating device, 32 ... heater, 40 ... air permeability measuring device, 41, 41a ... air permeability measuring unit, 42 ... main body, 43 ... driving unit, 43a ... support unit, 44 ... control unit, 50 ... transport speed control device , 60 ... main controller, 70 ... VOC processing device, 100 ... housing, 102 ... electrospinning chamber, 110, 110a1, 110a2 ... nozzle block, 150 ... collector, 152 ... insulating member, 160 ... power supply device, 170 ... auxiliary Belt device, 172 ... auxiliary belt, 174 ... roller for auxiliary belt, a ... conveying direction, b ... width direction of long sheet, P ... air permeability, <P> ... average air permeability, V Transport speed, W ... long sheet, ΔP ... the amount of deviation

Claims (11)

A transport device for transporting a long sheet at a predetermined transport speed;
A spinning device for depositing nanofibers on the long sheet conveyed by the conveying device;
An air permeability measuring device for measuring the air permeability of the long sheet on which the nanofibers are deposited by the spinning device;
A nanofiber manufacturing apparatus, comprising: a conveyance speed control device that controls the conveyance speed based on the air permeability measured by the air permeability measurement device. In the nanofiber manufacturing apparatus according to claim 1,
The nanofiber manufacturing apparatus, wherein the transport speed control device controls the transport speed based on a deviation amount between an air permeability measured by the air permeability measuring device and a predetermined target air permeability. In the nanofiber manufacturing apparatus according to claim 2,
The said conveyance speed control apparatus controls the said conveyance speed in consideration of the time change rate of the said deviation | shift amount, The nanofiber manufacturing apparatus characterized by the above-mentioned. In the nanofiber manufacturing apparatus according to any one of claims 1 to 3,
The air permeability measuring device includes an air permeability measuring unit that measures the air permeability of the long sheet, and a drive unit that reciprocates the air permeability measuring unit in a predetermined cycle along the width direction of the long sheet. An apparatus for producing nanofiber, comprising: In the nanofiber manufacturing apparatus according to claim 4,
The transport speed control device has an average air permeability obtained by averaging the air permeability measured by the air permeability measuring unit in the predetermined period or a time corresponding to n times the period (where n is a natural number). The nanofiber manufacturing apparatus characterized by controlling the said conveyance speed based on. In the nanofiber manufacturing apparatus according to any one of claims 1 to 3,
The air permeability measuring device includes a plurality of air permeability measuring units arranged at a plurality of positions in the width direction of the long sheet as an air permeability measuring unit that measures the air permeability of the long sheet. Nanofiber manufacturing equipment. In the nanofiber manufacturing apparatus according to claim 6,
The said conveyance speed control apparatus controls the said conveyance speed based on the average air permeability obtained by averaging the air permeability measured by these several air permeability measurement parts, The nanofiber manufacturing apparatus characterized by the above-mentioned. In the nanofiber manufacturing apparatus according to any one of claims 1 to 7,
An apparatus for producing nanofibers, further comprising a heating device that is disposed between the spinning device and the air permeability measuring device and that heats the long sheet on which the nanofibers are deposited. In the nanofiber manufacturing apparatus according to any one of claims 1 to 8,
A nanofiber production apparatus comprising a plurality of spinning apparatuses arranged in series along a predetermined conveyance direction in which the long sheet is conveyed as the spinning apparatus. In the nanofiber manufacturing apparatus according to any one of claims 1 to 9,
The spinning apparatus is an electrospinning apparatus.   While the nanofibers are deposited on the long sheet that is being conveyed at a predetermined conveyance speed, the air permeability of the long sheet on which the nanofibers are deposited is measured, and based on the measured air permeability of the long sheet And controlling the conveying speed of the long sheet.

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