JP2014227632A - Apparatus for producing sheet, apparatus for measuring fiber diameter, and method for measuring fiber diameter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure a fiber diameter of a nanofiber in a sheet composed of nanofibers online.SOLUTION: The apparatus for measuring a fiber diameter includes: a visible light irradiation means 181 for irradiating a sheet 302 with a visible light including a plurality of wavelengths; a color camera 182 for receiving a reflection light reflected by the sheet 302 or a transmitted light transmitted through the sheet 302 with an imaging element 184; a first transportation means 151 for transporting the visible light irradiation means 181 and the color camera 182 in a first direction relative to the sheet 302; and a fiber diameter information creation unit 109 for creating relative information regarding a fiber diameter of a fiber in the sheet 302 by comparing the received light information obtained from the color camera 182 and including the information of intensity of light of the plurality of the wavelengths respectively with reference information obtained preliminarily and including information of reference intensity corresponding to the plurality of the wavelengths.

Description

  The present invention relates to a sheet manufacturing apparatus for manufacturing a sheet by depositing fibers obtained by an electrospinning method, an apparatus for measuring a fiber diameter of a fiber in the manufactured sheet, and a method for measuring the fiber diameter.

  In a sheet such as a nonwoven fabric, the basis weight, thickness, fiber diameter, etc. of the sheet are indicators of the quality of the manufactured sheet.

  However, in the manufacturing process, the basis weight of the sheet produced by depositing the so-called nanofibers with submicron order and nano order fiber diameters obtained by electrospinning (electrospinning) and the fiber diameter of the nanofibers in the sheet (manufacturing) It is considered very difficult to measure online).

  Conventionally, as a method for measuring a specific fiber diameter of a nanofiber in a sheet on which nanofibers are deposited, a method of measuring a fiber diameter by observing a part of a finished sheet cut out with a microscope has been adopted. . However, in this method, since the sheet must be cut, the fiber diameter of the sheet being manufactured cannot be measured online.

  On the other hand, Patent Document 1 describes a method of measuring the fiber diameter of a single fiber using laser light. Patent Document 2 describes a method of measuring the film thickness of a sheet using infrared rays.

JP 2002-107121 A JP 2005-164251 A

  However, with the method of measuring the fiber diameter with laser light, it is considered impossible to measure the fiber diameter of the nanofibers constituting the sheet as it is in the sheet state. Moreover, in the method of measuring the reflection of infrared rays, only the film thickness of the sheet can be measured, and in the case of a non-woven fabric, it is assumed that the measurement error is large.

  The present invention has been made in view of the above problems, and the fiber diameter of the fibers constituting the sheet is measured not only after the production of the sheet but also during the production of the sheet, and the fiber diameter of the fibers constituting the sheet is measured. An object of the present invention is to provide a sheet manufacturing apparatus, a fiber diameter measuring apparatus, and a fiber diameter measuring method that can be performed.

  In order to achieve the above object, a sheet manufacturing apparatus according to the present invention is a sheet manufacturing apparatus for manufacturing a sheet by depositing fibers obtained by an electrospinning method and feeding the fibers in a first direction which is a transfer direction. A visible light irradiating means for irradiating the sheet with visible light including a wavelength of the light; and an image sensor that reflects the reflected light reflected by the sheet or the transmitted light transmitted through the sheet. A color camera for receiving light using the visible light irradiating means, a first moving means for moving the color camera relatively in a first direction relative to the sheet deposited and fed in the first direction, By comparing light reception information including light intensity information for each of a plurality of wavelengths acquired from a color camera with reference information including reference intensity information corresponding to the plurality of wavelengths acquired in advance. Characterized in that it comprises a fiber diameter information creation unit for creating relative information on fiber diameter of the fibers in the sheet.

  According to this, the fiber diameter of the fiber which comprises a sheet | seat non-destructively with respect to the sheet | seat during manufacture can be measured. Therefore, it is possible to relatively grasp the change in the fiber diameter in the manufacturing process of the sheet, and it is possible to monitor the transition of the fiber diameter, which is an index of the sheet quality.

  Further, the fiber diameter information creating unit acquires correspondence information indicating a relationship between a difference between the light reception information and the reference information and a fiber diameter, and based on the difference between the light reception information and the reference information, an absolute value related to the fiber diameter is obtained. Information may be created.

  According to this, since not only the relative transition of the fiber diameter but also the fiber diameter can be evaluated with absolute information, quality differences between sheets in different lots should be evaluated appropriately. Is possible.

  Further, when the reflected light reflected by the sheet is received, the visible light irradiation means may be annularly arranged around the color camera.

  According to this, it is possible to reflect as much visible light as possible on the sheet and receive a large amount of reflected light by the color camera, thereby improving the measurement accuracy. In addition, the visible light irradiation means and the color camera can be compactly configured as one unit.

  Further, the visible light irradiating means and a second moving means for moving the color camera relative to the sheet in a second direction along a surface direction of the sheet intersecting the first direction may be provided. .

  According to this, it becomes possible to measure the fiber diameter distribution in the second direction (for example, the width direction) of the sheet being manufactured. Accordingly, it is possible to measure a change in the distribution of the fiber diameter in the width direction in the manufacturing process of the sheet, and feed back the measurement result to the manufacturing condition of the sheet to manufacture a sheet with a stable distribution in the basis width direction. .

  In order to achieve the above object, a fiber diameter measuring apparatus according to the present invention is an apparatus for measuring the fiber diameter of the fiber in a sheet manufactured by depositing fibers obtained by an electrospinning method. A visible light irradiating means for irradiating the sheet with visible light including a wavelength of the light; and an image sensor that reflects the reflected light reflected by the sheet or the transmitted light transmitted through the sheet. A color camera that receives light using a color sensor, light reception information including light intensity information for each of a plurality of wavelengths acquired from the color camera, and reference information including reference intensity information corresponding to the plurality of wavelengths acquired in advance are compared. And a fiber diameter information creating unit that creates relative information on the fiber diameter of the fiber in the sheet.

  According to this, the fiber diameter can be measured in a non-destructive manner for a sheet formed of fibers having a fiber diameter of sub-micron order or nano order. Therefore, the fiber diameter of the fibers constituting the sheet can be grasped relatively with respect to the sheet in the manufacturing process or the manufactured sheet, and the distribution of the fiber diameter, which is an index of the sheet quality, between the lots The difference can be measured.

  Further, the fiber diameter information creating unit acquires correspondence information indicating a relationship between a difference between the light reception information and the reference information and a fiber diameter, and based on the difference between the light reception information and the reference information, an absolute value related to the fiber diameter is obtained. Information may be created.

  According to this, since the fiber diameter of the fibers constituting the sheet can be evaluated with absolute information, the quality difference between the sheet manufactured in the past and the newly manufactured sheet can be evaluated. It becomes possible to carry out appropriately.

  In order to achieve the above object, the fiber diameter measuring method according to the present invention is a fiber diameter measuring method for measuring the fiber diameter of the fiber in a sheet produced by depositing fibers obtained by electrospinning. Irradiating the sheet with visible light including a plurality of wavelengths relative to the sheet by visible light irradiating means, and the reflected light reflected by the sheet by the visible light irradiated by the visible light irradiating means, Alternatively, the transmitted light that has passed through the sheet is received by a color camera having an image sensor that moves relative to the sheet, and received light information including light intensity information for each of a plurality of wavelengths acquired from the color camera; The relative information on the fiber diameter of the fiber in the sheet is compared with the reference information including reference intensity information corresponding to the plurality of wavelengths acquired in advance. And wherein the creating by the information creation unit.

  According to this, the fiber diameter of the fiber which comprises a sheet | seat non-destructively with respect to the sheet | seat in manufacture can be measured, and transition of the fiber diameter which is an index of the quality of a sheet | seat can be monitored.

  In addition, implementing the program for making a computer perform each process included in the said fiber diameter measuring method also corresponds to implementation of this invention. Of course, implementing the recording medium in which the program is recorded also corresponds to the implementation of the present invention.

  According to the present invention, it is possible to measure the fiber diameter in a non-destructive manner in a manufacturing process for a sheet manufactured by depositing nanofibers obtained by an electrospinning method.

FIG. 1 is a perspective view showing a sheet manufacturing apparatus. FIG. 2 is a perspective view showing a cross section of the outflow body. FIG. 3 is a side view showing the fiber diameter measuring device together with a sheet. FIG. 4 is a plan view showing the fiber diameter measuring device from below. FIG. 5 is a block diagram showing a functional part of the fiber diameter information measuring apparatus together with a mechanism part. FIG. 6 is a graph showing the reference information and the light reception information. FIG. 7 is a graph showing difference information due to changes in fiber diameter together with difference information due to changes in other parameters. FIG. 8 is a block diagram showing a functional part of a fiber diameter information measuring device according to another aspect together with a mechanism part. FIG. 9 is a side view showing another embodiment of the fiber diameter measuring device together with a sheet.

  Next, embodiments of a sheet manufacturing apparatus, a fiber diameter measuring apparatus, and a fiber diameter measuring method according to the present invention will be described with reference to the drawings. The following embodiments are merely examples of the sheet manufacturing apparatus, the fiber diameter measuring apparatus, and the fiber diameter measuring method according to the present invention. Accordingly, the scope of the present invention is defined by the wording of the claims with reference to the following embodiments, and is not limited to the following embodiments. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept of the present invention are not necessarily required to achieve the object of the present invention. It will be described as constituting a preferred form.

  FIG. 1 is a perspective view showing a sheet manufacturing apparatus.

  As shown in the figure, the sheet manufacturing apparatus 100 is an apparatus for manufacturing a sheet by depositing nanofibers 301 which are fibers obtained by an electrospinning method and feeding them in a first direction (X-axis direction) which is a transfer direction. is there. In the case of the present embodiment, the sheet manufacturing apparatus 100 electrically stretches the raw material liquid 300 in the space to manufacture the nanofibers 301, deposits the nanofibers 301 on the sheet-like collection member 159, and the sheet 302. Is provided with an effluent body 101, a supply electrode 102, a charging electrode 103, a charging power source 104, a first moving means 151, and a fiber diameter measuring device 108.

  FIG. 2 is a perspective view showing a cross section of the outflow body.

  As shown in these drawings, the outflow body 101 is a member for causing the raw material liquid 300 for producing the nanofiber 301 to flow out into the space. In the case of the present embodiment, the effluent body 101 causes the raw material liquid 300 to uniformly flow out from the outflow holes 111 arranged in the horizontal direction (Y-axis direction in FIG. 1). Specifically, the outflow body 101 is a hollow member obtained by extending a triangular prism in the horizontal direction, and a plurality of outflow holes 111 opened downward are linearly arranged in the longitudinal direction (Y-axis direction). A cylindrical storage space 112 that is provided in a state and communicates with the plurality of outflow holes 111 is provided inward. The outer shape of the outflow body 101 is a triangular prism shape, and the outflow body 101 is arranged such that a cross section (a cross section virtually cut along the XZ plane) is an inverted triangle. Further, the portion corresponding to the lower apex of the outflow body 101 (the lowermost portion in the Z-axis direction) is a flat portion 113 extending in the XY plane, and the front end opening 118 of the outflow hole 111 is arranged in the flat portion 113. It is supposed to be.

  The outflow body 101 is made of an insulating material. For example, the outflow body 101 is formed of a resin, and examples of the resin material constituting the outflow body 101 include polyacetal and polyetheretherketone. By forming the outflow body 101 with an insulating material, it is possible to suppress the generation of ion wind from the surface of the outflow body 101.

  The storage space 112 is a space that is formed inside the outflow body 101 and stores the raw material liquid 300 supplied from the supply means 107 (see FIG. 1). The storage space 112 is connected to the plurality of outflow holes 111 and supplies the raw material liquid 300 to the outflow holes 111 at the same time.

  As described above, the storage space 112 has a function of temporarily storing the raw material liquid 300 in the vicinity of the outflow holes 111 and supplying the raw material liquid 300 to the plurality of outflow holes 111 with an equal pressure. The raw material liquid 300 can be allowed to flow out from each outflow hole 111 in an even state. Therefore, it is possible to suppress spatial unevenness in the quality of the manufactured nanofiber 301. Further, in the storage space 112, charges are supplied to the raw material liquid 300 from the supply electrode 102 disposed in the storage space 112.

  The supply electrode 102 is an electrode for supplying charges to the raw material liquid 300. In the case of the present embodiment, the supply electrode 102 is disposed in the storage space 112 of the outflow body 101 so as to extend in a direction intersecting the tube axis of the outflow hole 111, and the storage tank side opening of the outflow hole 111 communicating with the storage space 112. It is a rod-shaped member having a smooth curved surface at a position facing at least the portion 110. Specifically, as the supply electrode 102, a stainless steel round bar can be exemplified. The material of the supply electrode 102 is not particularly limited as long as it has conductivity, but it is preferable to select a material having low reactivity with the raw material liquid 300. In this respect, stainless steel is a reasonable material. Further, the shape of the supply electrode 102 is not limited to a rod shape having a circular cross section, but may be a semicircular cross section. The supply electrode 102 may be hollow such as a cylindrical shape. Alternatively, the outflow body 101 may be formed of a conductive member, and the outflow body 101 may function as the supply electrode 102.

  The charging electrode 103 is arranged at a predetermined interval from the efflux body 101 or the supply electrode 102, and becomes a high voltage or a low voltage with respect to the supply electrode 102 arranged inside the efflux body 101, It is a member for inducing charges in the raw material liquid 300 and a member having conductivity. In the case of the present embodiment, the charging electrode 103 also functions as an attracting means for attracting the nanofiber 301 manufactured in the space to a predetermined place, so as to face the flat portion 113 of the outflow body 101. The collecting member 159 is disposed on the opposite side of the outflow body 101. When a positive voltage is applied to the supply electrode 102, a negative charge is induced to the charging electrode 103, and when a negative voltage is applied to the supply electrode 102, a positive charge is induced to the charging electrode 103. .

  The charging power source 104 (see FIG. 1) is a power source that can apply a high voltage to the effluent body 101. The charging power source 104 is generally preferably a DC power source. The voltage applied between the charging electrode 103 and the supply electrode 102 by the charging power source 104 is preferably set from a value in the range of 5 KV to 50 KV.

  If the one electrode of the charging power source 104 is set to the ground potential and the charging electrode 103 is grounded as in the present embodiment, the relatively large charging electrode 103 can be set to the ground state, thereby improving safety. It becomes possible to contribute to.

  Note that a power source may be connected to the charging electrode 103 to maintain the charging electrode 103 at a high voltage, and the supply electrode 102 may be grounded. Further, the charging electrode 103 and the outflow body 101 may be in a connection state in which neither the grounding electrode 103 nor the outflow body 101 is grounded.

  FIG. 3 is a side view showing the fiber diameter measuring device together with a sheet.

  The fiber diameter measuring device 108 includes a visible light irradiation unit 181, a color camera 182, and a fiber diameter information creation unit 109, and the visible light irradiation unit 181 applies visible light to a sheet 302 made of fibers obtained by electrospinning. Is transmitted through the sheet 302, or reflected light reflected by the sheet 302 is received by the color camera 182, and the fibers of the nanofiber 301 constituting the sheet 302 based on the received transmitted light or reflected light. This is a device for measuring the diameter.

  The visible light irradiation unit 181 is a device that irradiates the sheet 302 with visible light including a plurality of wavelengths. Here, visible light means an electromagnetic wave having a wavelength in the range of 350 nm to 780 nm. The visible light including a plurality of wavelengths means visible light having a plurality of peaks included in the wavelength range or continuous light. Specifically, as the visible light irradiation means 181, a white LED (Light Emitting Diode) or a combination of a plurality of LEDs that emit light at different wavelengths (for example, an LED that emits red light and an LED that emits green light and blue light) Examples that emit continuous light, such as incandescent lamps.

  FIG. 4 is a plan view showing the fiber diameter measuring device from below.

  In the case of the present embodiment, the visible light irradiation means 181 includes a plurality of white LEDs 183 that can irradiate visible light including a plurality of wavelengths arranged in a ring around the color camera 182. As a result, the visible light irradiation means 181 can be arranged in a compact manner, and a large amount of visible light can be reflected by the sheet 302 and received by the color camera 182.

  The color camera 182 is an apparatus that receives reflected light reflected by the sheet 302 or transmitted light that has passed through the sheet 302 using the image sensor 184 (see FIG. 3). is there.

  The image sensor 184 is a solid-state image sensor such as a CCD or CMOS, and can measure luminance for each color (wavelength) by using a plurality of filters. The image sensor 184 can arbitrarily adopt unit elements that react to light, such as one-dimensionally arranged units or two-dimensionally arranged units.

  In the case of this embodiment, the color camera 182 includes a lens 185 for concentrating visible light on the image sensor 184.

  FIG. 5 is a block diagram showing a functional part of the fiber diameter information measuring apparatus together with a mechanism part.

  As shown in the figure, the fiber diameter information creating unit 109 receives the light reception information including the light intensity information for each of the plurality of wavelengths acquired from the color camera 182 by the light reception information acquisition unit 191 and the reference information acquisition unit 192 in advance. In the processing unit in which the relative fiber information creating unit 193 creates relative fiber information that is relative information on the fiber diameter of the fiber in the sheet 302 by comparing with reference information including reference intensity information corresponding to a plurality of wavelengths. is there.

  Specifically, for example, in the initial stage of manufacturing the sheet 302, the light reception information acquisition unit 191 uses at least 1 in the range of 450 nm to 500 nm, for example, as the reference intensity information with the light reflectance corresponding to a plurality of wavelengths (wavelength bands). Light intensity information at a wavelength is used as reference intensity information, light intensity information at at least one wavelength in the range of 500 nm to 550 nm is reference intensity information, and light intensity information at at least one wavelength in the range of 550 nm to 600 nm is reference intensity information. The reference information including these is stored in the storage unit 199. Thereafter, the light reception information acquisition unit 191 acquires the light reception information along with the relative movement between the sheet 302 and the fiber diameter measuring device 108. The relative fiber information creation unit 193 compares the reference information as the light reflectance acquired by the reference information acquisition unit 192 from the storage unit 199 with the light reception information for each wavelength. If the absolute value of the difference (reflectance difference) between the reference information and the received light information does not exceed the threshold value as a result of the comparison, the relative fiber information creation unit 193 creates information indicating no change. On the other hand, when the threshold is exceeded, warning (or notification) information is created.

  The wavelength range (wavelength band) for acquiring the intensity information is an example, and is not limited to this. Light of at least two different wavelengths (two wavelength bands) in the visible light range of 350 nm or more and 780 nm or less. What is necessary is just to acquire the intensity information as the reflectance. Further, as shown in FIG. 6, if a large amount of intensity information is acquired, for example, as reflectance at a plurality of wavelengths, it is considered that measurement accuracy is improved. In the present embodiment, for example, a sheet 302 made of fibers having a fiber diameter of 300 nm is used as a reference information sheet, and the reflectance at each wavelength is measured.

  The relative fiber information creation unit 193 acquires the difference between the reference intensity information and the intensity information for each wavelength, and the difference (reflectance difference) at each wavelength is the same or substantially the same, so that the reference information and the light reception are the same. When the absolute value of the difference from the information does not exceed the threshold value, it is determined that there is no change in the fiber diameter in the manufactured sheet 302. Specifically, for example, as shown in FIG. 7, if the fiber diameter changes, a large difference is recognized in the difference between the intensity information and the reference intensity information at each wavelength (difference in reflectance), whereas other parameters No significant difference (for example, a difference exceeding 2.5% to 3% in absolute value) is recognized in the difference between the intensity information at each wavelength and the reference intensity information. Therefore, when there is a large difference in the difference between the intensity information at each wavelength and the reference intensity information (for example, when the difference exceeds a threshold (for example, 2.5% to 3%)), it is determined that the fiber diameter has changed. It doesn't matter. As a result, it is possible to measure changes in fiber diameter excluding changes in other parameters.

  In FIG. 7, as a case where a change in the fiber diameter occurs, for example, a 5% change exceeding the threshold value as the absolute value of the difference between the intensity information and the reference information (difference in reflectance) at each wavelength is a wavelength of 450 nm to 550 nm. It is generated centering around a wavelength of 500 nm. This is because when the fiber diameter of the fibers constituting the sheet 302 and the wavelength of light are the same or substantially the same, a change in the difference (difference in the reflectance of light) tends to occur largely around that wavelength. In the present embodiment, the reference information and the light reception information are measured using the same type of material sheet 302, the difference in the difference is large around the wavelength of about 500 nm, and the fiber diameter of the light reception information sheet 302 changes to about 500 nm. The fiber was actually observed with a microscope, and it was confirmed that the fiber diameter was 500 nm.

  Further, as shown in FIG. 8, the fiber diameter measuring apparatus 108 displays difference information indicating a difference between the light reception information acquired by the light reception information acquisition unit 191 and the reference information acquired by the reference information acquisition unit 192, as a difference information creation unit 194. The absolute fiber diameter creating unit 195 compares the difference information with the difference information and the fiber diameter that are created in advance and stored in the storage unit 199, and the absolute information about the fiber diameter is compared. It may be created.

  Here, the correspondence information is derived based on the light reception information acquired for the sheet formed of fibers having a known fiber diameter and the light reception information acquired for a sheet formed of fibers having a known fiber diameter different from the fiber diameter. Information.

  According to this, since the fiber diameter of the fibers constituting the sheet 302 can be evaluated with absolute information, it is possible to evaluate the fiber diameter between the sheets 302 in different lots.

  The first moving unit 151 is a device that moves the visible light irradiating unit 181 and the color camera 182 relative to the sheet 302 in a first direction (X-axis direction in the drawing) as a transfer direction. In the case of the present embodiment, the first moving means 151 winds the collecting member 159 and a long sheet-like collecting member 159 that accumulates and collects the nanofibers 301 manufactured by the electrospinning method. And a roll 158 that can move the manufactured sheet 302. While collecting the nanofibers 301 on the long collection member 159, the collection member 159 is transferred from one roll 158 to the other roll 158. Is slowly sent in the first direction (X-axis direction in the figure) to produce a long sheet 302 composed of nanofibers 301, while the fiber diameter measuring device 108 provided in the sheet manufacturing apparatus 100 is The nanofiber 301 is deposited and moved relative to the sheet 302 formed by being sent in the first direction in the first direction (X-axis direction in the figure). That.

  That is, the fiber diameter measuring device 108 is manufactured by depositing the nanofiber 301 on the collecting member 159, and is transferred in the first direction (X-axis direction in the drawing) by the first moving means 151 (the transfer direction is the X-axis in the drawing). The first direction (X-axis direction in the drawing) is fixedly arranged above the sheet 302 immediately after being negatively). That is, the fiber diameter measuring device 108 fixedly arranged in the sheet manufacturing apparatus 100 moves relative to the sheet 302 when the sheet 302 moves in the transport direction. This makes it possible to grasp the distribution of the fiber diameter of the sheet 302 in the first direction (X-axis direction in the figure).

  In the case of the present embodiment, the sheet manufacturing apparatus 100 further includes second moving means 152. The second moving means 152 is a second direction along the surface direction of the sheet 302 that intersects the first direction with respect to the sheet 302 with respect to the visible light irradiating means 181 and the color camera 182 (Y-axis direction in this embodiment). It is a device which moves relative to. Specifically, for example, as shown in FIG. 1 or the like, the second moving unit 152 includes a rail 157 arranged to extend in the second direction (Y-axis direction in the drawing), a visible light irradiation unit 181, and a color camera. A guide 156 that holds the 182 along the rail 157 so as to reciprocate, and a drive device (not shown) that drives the guide 156 along the rail 157 are provided. This makes it possible to measure the fiber diameter distribution in the width direction of the sheet 302 (Y-axis direction in the figure).

  Further, by combining the first moving unit 151 and the second moving unit 152, the fiber diameter distribution of the sheet 302 can be measured two-dimensionally.

  Note that the sheet manufacturing apparatus 100 may include a plurality of fiber diameter measuring devices 108 arranged in the second direction (in the Y-axis direction in the drawing). Accordingly, it is possible to measure the fiber diameter distribution in the second direction of the sheet 302 without driving the visible light irradiation unit 181 and the color camera 182 above the sheet 302.

  As shown in FIG. 1, the supply means 107 is a device that supplies the raw material liquid 300 to the effluent body 101, and transports the raw material liquid 300 at a predetermined pressure and amount, and a container 171 that stores the raw material liquid 300 in large quantities. A pump and a dispensing system (not shown) as supply means and a guide tube 172 for guiding the raw material liquid 300 are provided.

  Here, the raw material liquid 300 contains a resin (polymer resin) constituting the nanofiber 301 as a solute and a solvent for dissolving or dispersing the solute.

  Solutes include polypropylene, polyethylene, polystyrene, polyethylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, poly-m-phenylene terephthalate, poly-p-phenylene isophthalate, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene Copolymer, polyvinyl chloride, polyvinylidene chloride-acrylate copolymer, polyacrylonitrile, polyacrylonitrile-methacrylate copolymer, polycarbonate, polyarylate, polyester carbonate, polyamide, aramid, polyimide, polycaprolactone, polylactic acid, polyglycol Acid, collagen, polyhydroxybutyric acid, polyvinyl acetate, polypeptide, etc. and their copolymers The polymeric resin can be exemplified. Further, the solute may be one selected from the above, or a plurality of types may be mixed. In addition, the above is an illustration and this invention is not limited to the said solute.

  Examples of the solvent include volatile organic solvents. Specifically, methanol, ethanol, 1-propanol, 2-propanol, hexafluoroisopropanol, tetraethylene glycol, triethylene glycol, dibenzyl alcohol, 1,3-dioxolane, 1,4-dioxane, methyl ethyl ketone, methyl isobutyl Ketone, methyl-n-hexyl ketone, methyl-n-propyl ketone, diisopropyl ketone, diisobutyl ketone, acetone, hexafluoroacetone, phenol, formic acid, methyl formate, ethyl formate, propyl formate, methyl benzoate, ethyl benzoate, benzoate Propyl acid, methyl acetate, ethyl acetate, propyl acetate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, methyl chloride, ethyl chloride, methylene chloride, chloroform, o-chloroto Ene, p-chlorotoluene, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, trichloroethane, dichloropropane, dibromoethane, dibromopropane, methyl bromide, ethyl bromide, propyl bromide, acetic acid, Benzene, toluene, hexane, cyclohexane, cyclohexanone, cyclopentane, o-xylene, p-xylene, m-xylene, acetonitrile, tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, pyridine, water Etc. can be listed. Moreover, the kind selected from the above may be used, and a plurality of kinds may be mixed. In addition, the above is an illustration and this invention is not limited to the said solvent.

Furthermore, an inorganic solid material or the like may be added to the raw material liquid 300. Examples of the inorganic solid material include oxides, carbides, nitrides, borides, silicides, fluorides, sulfides, and the like. From the viewpoint of heat resistance and workability of the nanofiber 301 to be manufactured. It is preferable to use an oxide. Examples of the oxide include Al ₂ O ₃ , SiO ₂ , TiO ₂ , Li ₂ O, Na ₂ O, MgO, CaO, SrO, BaO, B ₂ O ₃ , P ₂ O ₅ , SnO ₂ , ZrO ₂ , K. ₂ O, Cs ₂ O, ZnO, Sb ₂ O ₃ , As ₂ O ₃ , CeO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , MnO, Fe ₂ O ₃ , CoO, NiO, Y ₂ O ₃ , Lu ₂ Examples thereof include O ₃ , Yb ₂ O ₃ , HfO ₂ , Nb ₂ O _{5 and the} like. Moreover, the kind selected from the above may be used, and a plurality of kinds may be mixed. Note that the above is an example, and the present invention is not affected by whether or not the additive is included in the raw material liquid 300.

  The mixing ratio of the solvent and the solute in the raw material liquid 300 varies depending on the type of solvent selected and the type of solute, but the amount of solvent is preferably between about 60 wt% and 98 wt%. Preferably, the solute is in the range of 5% to 30% by weight.

  Next, the manufacturing method of the sheet | seat 302 by the sheet manufacturing apparatus 100 of the said structure and the fiber diameter measuring method are demonstrated.

  First, the raw material liquid 300 is supplied to the effluent 101 by the supply means 107 (supply process). Thus, the raw material liquid 300 is filled in the storage space 112 of the effluent body 101.

  Next, a high voltage is applied between the supply electrode 102 and the charging electrode 103 by the charging power source 104. As a result, the charge is transferred to the raw material liquid 300, and the raw material liquid 300 is charged (charging process).

  The charging step and the supplying step are performed at the same time, and the charged raw material liquid 300 flows out from the front end opening 118 of the outflow body 101 into the space (outflow step).

  Here, the raw material liquid 300 flowing out from the front end opening 118 forms a liquid reservoir 303 (see FIG. 2) called a tailor cone that covers the front end opening 118 and hangs down from the flat surface portion 113. The liquid reservoir 303 is formed for each of the plurality of tip opening portions 118, and the charged raw material liquid 300 hangs down from the tip in a string shape.

  Next, the raw material liquid 300 that has flew in the space to some extent causes an electrostatic explosion as the solvent evaporates, and is stretched by an electric field to produce a nanofiber 301 with a small wire diameter (nanofiber manufacturing process).

  In this state, the nanofiber 301 is attracted to the collecting member 159 of the collecting means 105 by an electric field generated between the charging electrode 103 (attracting means) disposed behind the collecting means 105 and the supply electrode 102 ( Attraction process).

  As described above, the nanofiber 301 is deposited on the collecting member 159 (deposition step). Since the collecting means 105 is slowly transferred by the roll 158 which is the first moving means 151, the deposited nanofibers 301 are elongated belt-like sheets 302 extending in the transfer direction (the negative direction of the X axis in the figure). And transferred.

  Next, the visible light irradiation means 181 irradiates the sheet 302 with visible light while moving the visible light irradiation means 181 and the color camera 182 relative to the sheet 302 in the first direction (X-axis direction in the figure). The color camera 182 measures the fiber diameter by receiving the reflected light reflected by the sheet 302 (fiber diameter measuring step). In the case of the present embodiment, the visible light irradiation means 181 and the color camera 182 measure the fiber diameter while reciprocating in the width direction (Y-axis direction in the drawing) of the sheet 302 that is the second direction.

  By using the above-described sheet manufacturing apparatus 100 and adopting the fiber diameter measuring method, it is possible to measure the fiber diameter of the sheet 302 online with respect to the sheet 302 continuously manufactured by depositing the nanofibers 301. It becomes. Accordingly, it is possible to observe the change in the fiber diameter in the feeding direction of the sheet 302 (first direction (transfer direction), X-axis direction in the figure), and adjust the sheet manufacturing apparatus 100 according to the change in the fiber diameter. Thereby, the fiber diameter of the fiber in the sheet 302 can be stabilized.

  In addition, by reciprocating the fiber diameter measuring device 108 in the width direction of the sheet 302 (second direction, Y-axis direction in the figure), the distribution of the fiber diameter in the width direction can also be measured nondestructively. Therefore, the fiber diameter distribution of the fibers constituting the sheet 302 can be measured two-dimensionally, the quality of the sheet 302 can be appropriately managed, and the sheet manufacturing apparatus 100 can be adjusted to provide a stable quality sheet 302. Can be manufactured.

  In addition, this invention is not limited to the said embodiment. For example, another embodiment realized by arbitrarily combining the components described in this specification and excluding some of the components may be used as an embodiment of the present invention. In addition, the present invention includes modifications obtained by making various modifications conceivable by those skilled in the art without departing from the gist of the present invention, that is, the meaning described in the claims. It is.

  For example, as shown in FIG. 9, the visible light irradiation means 181 is disposed on the opposite side of the sheet 302 from the color camera 182, and information on the fiber diameter of the fibers constituting the sheet 302 based on the intensity (attenuation factor) of transmitted light. Can be obtained.

  Further, the basis weight and thickness of the sheet 302 may be separately measured, and the information regarding the fiber diameter may be corrected using the measurement data.

  The present invention can be used for the production of a sheet and a nonwoven fabric made of nanofibers.

DESCRIPTION OF SYMBOLS 100 Sheet manufacturing apparatus 101 Outflow body 102 Supply electrode 103 Charging electrode 104 Charging power supply 105 Collection means 107 Supply means 108 Fiber diameter measuring apparatus 109 Fiber diameter information creation part 110 Reservoir side opening 111 Outflow hole 112 Storage space 113 Plane part 118 Tip Opening 151 First moving means 152 Second moving means 156 Guide 157 Rail 158 Roll 159 Collection member 171 Container 172 Guide tube 181 Visible light irradiation means 182 Color camera 184 Image sensor 185 Lens 191 Light reception information acquisition section 192 Reference information acquisition section 193 Relative fiber information creation unit 194 Difference information creation unit 195 Absolute fiber diameter creation unit 199 Storage unit 300 Raw material liquid 301 Nanofiber 302 Sheet

Claims (7)

A sheet manufacturing apparatus for manufacturing a sheet by depositing fibers obtained by an electrospinning method and sending it in a first direction which is a transfer direction,
Visible light irradiating means for irradiating the sheet with visible light including a plurality of wavelengths;
A color camera that receives reflected light reflected by the sheet, or transmitted light that has passed through the sheet, using an imaging element;
The visible light irradiation means, and a first moving means for moving the color camera relative to the sheet deposited and fed in the first direction in a first direction;
By comparing light reception information including light intensity information for each of a plurality of wavelengths acquired from the color camera with reference information including reference intensity information corresponding to the plurality of wavelengths acquired in advance, the fibers in the sheet A sheet manufacturing apparatus comprising: a fiber diameter information creating unit that creates relative information on a fiber diameter. Fiber diameter information creation part
The correlation information which shows the relationship between the difference of the said light reception information and the said reference information, and a fiber diameter is acquired, The absolute information regarding a fiber diameter is created based on the difference of the said light reception information and the said reference information. The sheet manufacturing apparatus described. The sheet manufacturing apparatus according to claim 1, wherein the visible light irradiation unit is annularly arranged around the color camera. further,
The said visible light irradiation means and the 2nd moving means to relatively move the said color camera to the 2nd direction along the surface direction of the said sheet | seat which cross | intersects the said 1st direction with respect to the said sheet | seat are provided. Sheet manufacturing equipment. An apparatus for measuring a fiber diameter of the fiber in a sheet manufactured by depositing fibers obtained by an electrospinning method,
Visible light irradiating means for irradiating the sheet with visible light including a plurality of wavelengths;
A color camera that receives reflected light reflected by the sheet, or transmitted light that has passed through the sheet, using an imaging element;
By comparing light reception information including light intensity information for each of a plurality of wavelengths acquired from the color camera with reference information including reference intensity information corresponding to the plurality of wavelengths acquired in advance, the fibers in the sheet A fiber diameter measuring apparatus provided with the fiber diameter information preparation part which produces the relative information regarding a fiber diameter. Fiber diameter information creation part
The correspondence information indicating the relationship between the difference between the light reception information and the reference information and the fiber diameter is acquired, and absolute information on the fiber diameter is created based on the difference between the light reception information and the reference information. The fiber diameter measuring apparatus as described. A fiber diameter measuring method for measuring the fiber diameter of the fiber in a sheet produced by depositing fibers obtained by electrospinning,
Irradiating the sheet with visible light irradiation means moving relative to the sheet with visible light including a plurality of wavelengths,
The visible light irradiated by the visible light irradiation means is reflected by the reflected light from the sheet, or the transmitted light transmitted through the sheet is received by a color camera having an image sensor that moves relative to the sheet,
By comparing light reception information including light intensity information for each of a plurality of wavelengths acquired from the color camera with reference information including reference intensity information corresponding to the plurality of wavelengths acquired in advance, the fibers in the sheet A fiber diameter measurement method in which relative information on the fiber diameter is created by a fiber diameter information creation unit.

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