SHEET MANUFACTURING APPARATUS

Abstract

A sheet manufacturing apparatus includes a defibrating unit that generates a defibrated material, a web forming unit that generates a web, a supply pipe that supplies a mixture together with air, and a sheet forming unit that presses the web to generate a sheet, the supply pipe is provided with a first rectifying plate having a substantially trapezoidal shape and extending in a supply direction of the mixture, and the first rectifying plate has a first base angle formed by a lower base in contact with an internal wall of the supply pipe and a first leg located upstream in the supply direction, the first base angle being 25 or more and less than 45, and a second base angle formed by the lower base and a second leg located downstream in the supply direction, the second base angle being 55 or more and less than 85.

Claims

1. A sheet manufacturing apparatus comprising: a defibrating unit that defibrates a raw material to generate a material containing fibers; a web forming unit that accumulates the material to generate a web; a supply pipe that supplies the material from the defibrating unit to the web forming unit together with air; and a forming unit that presses the web generated by the web forming unit to generate a sheet, wherein the supply pipe includes an inner wall provided with a first rectifying plate having a substantially trapezoidal shape and extending in a supply direction of the material, and the first rectifying plate has a first base angle formed by a lower base in contact with the inner wall of the supply pipe and a first leg located upstream in the supply direction, the first base angle being 25 or more and less than 45, and a second base angle formed by the lower base and a second leg located downstream in the supply direction, the second base angle being 55 or more and less than 85.

2. The sheet manufacturing apparatus according to claim 1, wherein the first base angle is 25 or more and less than 35.

3. The sheet manufacturing apparatus according to claim 1, wherein the second base angle is 55 or more and less than 65.

4. The sheet manufacturing apparatus according to claim 1, wherein the inner wall of the supply pipe is provided with a second rectifying plate having a substantially trapezoidal shape and extending in the supply direction of the material, and the first rectifying plate and the second rectifying plate are disposed such that upper bases thereof face each other.

5. The sheet manufacturing apparatus according to claim 4, wherein an interval between the upper base of the first rectifying plate and the upper base of the second rectifying plate is 20 mm or more.

6. The sheet manufacturing apparatus according to claim 1, wherein the first rectifying plate is disposed in a linear first pipe of the supply pipe, and a length of the lower base is or more and or less of a length of the first pipe.

7. The sheet manufacturing apparatus according to claim 1, further comprising a mixing unit that is provided between the defibrating unit and the supply pipe and mixes a binder for binding the fibers to each other with the material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 is a schematic side view illustrating a sheet manufacturing apparatus.

[0007] FIG. 2 is a side view of a supply pipe and a web forming unit.

[0008] FIG. 3 is a Y-Z sectional view of the supply pipe.

[0009] FIG. 4 is a Y-Z sectional view of the supply pipe.

[0010] FIG. 5 is a Y-Z sectional view of the supply pipe.

[0011] FIG. 6 is an experiment result illustrating a first base angle, a rectifying effect, and a material accumulation state in a rectifying plate.

[0012] FIG. 7 is an experiment result illustrating a second base angle, a rectifying effect, and a material accumulation state in the rectifying plate.

DESCRIPTION OF EMBODIMENTS

[0013] Hereinafter, a sheet manufacturing apparatus according to the present disclosure will be described in detail based on a preferred embodiment illustrated in the accompanying drawings.

[0014] Hereinafter, for convenience of description, as illustrated in FIGS. 1 to 5, three axes orthogonal to each other are referred to as an X-axis, a Y-axis, and a Z-axis. In addition, an X-Y plane including the X-axis and the Y-axis is a horizontal plane, and the Z-axis is vertical. The direction in which the arrow of each axis faces is referred to as +, and the opposite direction is referred to as .

[0015] In FIGS. 1 to 5, an upper side is referred to as up or upward, and a lower side is referred to as down or downward. In each of the drawings, a direction in which a material including a raw material or a fiber material flows together with air, that is, a direction in which the material advances with time is referred to as downstream, and a side opposite thereto is referred to as upstream.

[0016] As illustrated in FIG. 1, a sheet manufacturing apparatus 1 includes a raw material supply unit 11, a defibrating unit 13, a sorting unit 14, a mixing unit 17, a supply pipe 8, a dispersing unit 18, a web forming unit 19, a sheet forming unit 20, a cutting unit 21, a stock unit 22, a collecting unit 27, a humidifying unit 232, and a control unit 28.

[0017] In the sheet manufacturing apparatus 1, a raw material supplying step, a defibrating step, a sorting step, a mixing step, a dispersing step, a web forming step, a sheet forming step, and a cutting step are performed in this order.

[0018] Hereinafter, a configuration of each unit will be described.

[0019] As illustrated in FIG. 1, the raw material supply unit 11 has an input port and receives a raw material M1. The raw material supply unit 11 is a unit that performs the raw material supplying step of receiving the raw material M1 and then supplying the raw material M1 to the defibrating step through a chute 122. As the raw material M1, a sheet-like material made of a fiber-containing material containing fibers can be used. The fibers may be any of plant fibers, animal fibers, synthetic fibers, metal fibers, and the like. In addition, the raw material M1 may have any form such as cotton, woven fabric, or non-woven fabric. In addition, the raw material M1 may be used paper such as recycled paper produced by defibrating waste paper, or may be unused paper. Further, in the present embodiment, the raw material M1 is waste paper that has been used or is no longer needed.

[0020] A humidifying unit 231 is disposed above the chute 122. The humidifying unit 231 humidifies the raw material M1 in the chute 122. The humidifying unit 231 has a filter (not illustrated) containing moisture and is constituted by a vaporizing type, in particular, a hot air vaporizing type humidifier that supplies humidified air with increased moisture to the raw material M1 by passing air through the filter. By supplying humidified air to the raw material M1, adhesion of the raw material M1 to the chute 122 and the like due to an electrostatic force can be suppressed.

[0021] The chute 122 is connected to the defibrating unit 13 through a pipe 241. The raw material M1 collected in the chute 122 passes through the pipe 241 and is transported to the defibrating unit 13.

[0022] The defibrating unit 13 is a unit that performs the defibrating step of defibrating the raw material M1 in air, that is, in a dry process. A defibrated material M3 can be produced from the raw material M1 by the defibration process in the defibrating unit 13. Here, defibrating means untangling coarsely crushed pieces of the raw material M1 formed by binding a plurality of fibers into individual fibers. Then, the material containing the untangled fibers becomes the defibrated material M3. The shape of the defibrated material M3 is linear or band-like. In addition, the defibrated material M3 may exist in a state in which the defibrated materials M3 are entangled with each other in a clump shape, that is, a state in which a so-called lump is formed.

[0023] For example, in the present embodiment, the defibrating unit 13 is constituted by an impeller mill having a rotor rotating at a high speed and a liner located on an outer periphery of the rotor. The raw material M1 that has flowed into the defibrating unit 13 is held between the rotor and the liner and defibrated.

[0024] In addition, the defibrating unit 13 can generate a flow of air from the chute 122 toward the sorting unit 14, that is, an airflow, by the rotation of the rotor. As a result, the raw material M1 can be suctioned from the pipe 241 to the defibrating unit 13. After the defibration process by the defibrating unit 13, the defibrated material M3 can be sent to the sorting unit 14.

[0025] The sorting unit 14 is a unit that performs the sorting step of sorting the defibrated material M3 according to the size of the fiber length. In the sorting unit 14, the defibrated material M3 is sorted into a first sorted material M4-1 and a second sorted material M4-2 larger than the first sorted material M4-1. The first sorted material M4-1 has a size suitable for the subsequent manufacturing of a sheet S. An average length of the first sorted material M4-1 is preferably 1 m or more and 30 m or less. On the other hand, the second sorted material M4-2 is not suitable for manufacturing the sheet S and includes, for example, an insufficiently defibrated material or a material in which defibrated fibers are excessively aggregated.

[0026] The sorting unit 14 includes a pipe 172 for supplying the first sorted material M4-1 to the mixing unit 17 and a pipe 242 for storing the second sorted material M4-2 in the collecting unit 27. A blower may be additionally provided in the middle of the pipe 242. By adding a blower, the second sorted material M4-2 can more easily reach the collecting unit 27 and be collected.

[0027] The mixing unit 17 is connected to the middle of the pipe 172, that is, between the defibrating unit 13 and the supply pipe 8 described later. The mixing unit 17 includes a screw feeder 174. When the screw feeder 174 is rotationally driven, a binder P1 can be quantitatively supplied into the pipe 172 in the form of powder or particles. The binder P1 supplied to the pipe 172 is mixed with the first sorted material M4-1 sorted in the sorting unit 14 at a desired ratio to form a mixture M7. By mixing the binder P1 with the first sorted material M4-1, the binder P1 is melted in the sheet forming unit 20 described later, and the fibers are bound to each other through the melted binder P1, so that the shape of the sheet S can be maintained in a desired form.

[0028] The binder P1 is not particularly limited. Examples thereof include starch, dextrin, glycogen, polyvinyl alcohol, polyacrylic acid, polyamide, and the like, and it is possible to use one or a combination of two or more selected from these.

[0029] In addition to the binder P1, for example, a coloring agent for coloring fibers, an aggregation suppressing agent for suppressing aggregation of fibers or aggregation of the binder P1, a flame retardant for making fibers or the like difficult to burn, a paper strength enhancing agent for enhancing paper strength of the sheet S, and the like may be included as materials supplied from the mixing unit 17. Alternatively, the above-described materials may be mixed with the binder P1 in advance to form a composite, and the composite may be supplied from the mixing unit 17.

[0030] A blower 173 is provided downstream of the pipe 172. That is, as illustrated in FIG. 2, a downstream end of the pipe 172 is connected to a suction port 175 of the blower 173. By the operation of the blower 173, a fiber material, that is, the mixture M7 of the first sorted material M4-1 and the binder P1 is sent out toward downstream in the pipe 172. The supply pipe 8 is provided downstream of the blower 173. As illustrated in FIG. 2, an upstream end of the supply pipe 8 is connected to a discharge port 176 of the blower 173. The blower 173 includes a motor that is driven by energization and blades that are rotated by the driving of the motor, generates an airflow by the rotation of the blades, and discharges, from the discharge port 176, air sucked from the suction port 175.

[0031] The first sorted material M4-1 and the binder P1 in the pipe 172 are introduced into the blower 173 and mixed by the airflow generated by the action of the rotating blades provided inside the blower 173. In addition, the blower 173 discharges an airflow toward downstream from the discharge port 176 by the action of the rotating blades. That is, an airflow toward the dispersing unit 18 described later is generated.

Description of Supply Pipe

[0032] As illustrated in FIGS. 2 and 3, the supply pipe 8 has a first portion 81, a second portion 82, and a third portion 83 connecting the first portion 81 and the second portion 82. Insides of the first portion 81, the second portion 82, and the third portion 83 are in communication with each other and constitute an internal flow path 800. Due to the airflow generated by the blower 173, the mixture M7 passes through the internal flow path 800 and is transported to a first dispersion chamber 3 constituting the dispersing unit 18.

[0033] The first portion 81 is located on a +Y side of the first dispersion chamber 3 side described later and extends linearly in a Y-axis direction. A first end portion 81A of the first portion 81 is connected to a connection port 54 of the first dispersion chamber 3. A second end portion 81B of the first portion 81 is connected to the third portion 83.

[0034] The second portion 82 extends linearly in a Z-axis direction. A third end portion 82A of the second portion 82 is connected to the third portion 83, and a fourth end 82B of the second portion 82 is connected to the discharge port 176 of the blower 173. The second portion 82 of the supply pipe 8 corresponds to a first pipe.

[0035] The third portion 83 is a curved or bent portion that is located between the first portion 81 and the second portion 82 and connects the first portion 81 and the second portion 82.

[0036] The first portion 81, the second portion 82, and the third portion 83 are formed of separate members and are connected to each other by a method such as welding, brazing, bonding with an adhesive, fitting, or caulking, thereby forming the supply pipe 8. However, the present disclosure is not limited thereto, and all or some of the first portion 81, the second portion 82, and the third portion 83 may be integrally formed.

[0037] It is preferable that the first portion 81, the second portion 82, and the third portion 83 are connected to each other so that a step is not generated on an inner wall surface in the vicinity of each boundary. As a result, flow path resistance of the internal flow path 800 can be suppressed to be low, and the mixture M7 can be efficiently supplied and transported to the first dispersion chamber 3.

[0038] The constituent material of the first portion 81, the second portion 82, and the third portion 83 constituting the supply pipe 8 is not particularly limited, and examples thereof include various metal materials such as an iron-based alloy such as stainless steel, aluminum or an aluminum-based alloy, and copper or a copper-based alloy, and various resin materials. The resin materials may be hard or flexible.

[0039] In addition, the supply pipe 8 includes a first rectifying plate 900 and a second rectifying plate 901 on an inner wall 910 of the second portion 82. Configurations of the first rectifying plate 900 and the second rectifying plate 901 will be described later.

[0040] The dispersing unit 18 performs the dispersing step of the mixture M7 supplied from the supply pipe 8. As illustrated in FIG. 2, the dispersing unit 18 includes the first dispersion chamber 3, a second dispersion chamber 4, and a third dispersion chamber 5. The dispersing unit 18 is a device for dispersing the mixture M7 in the air in the order of the first dispersion chamber 3, the second dispersion chamber 4, and the third dispersion chamber 5, and the degree of dispersion of the mixture M7 in the air, that is, the degree to which the air containing the mixture M7 becomes uniform and homogeneous progresses as the mixture M7 sequentially passes through the first dispersion chamber 3, the second dispersion chamber 4, and the third dispersion chamber 5. Hereinafter, configurations of the first dispersion chamber 3, the second dispersion chamber 4, and the third dispersion chamber 5 will be sequentially described from upstream to downstream.

[0041] The first dispersion chamber 3 is disposed above the third dispersion chamber 5. In the first dispersion chamber 3, the mixture M7 supplied from the supply pipe 8 is diffused in the first dispersion chamber 3 by using the airflow whose speed is changed when the mixture M7 passes through the connection port 54, and the mixture M7 is supplied from an opening 55 to the second dispersion chamber 4.

[0042] The second dispersion chamber 4 has a rotatable blade 61 and a porous screen 43 that separates the second dispersion chamber 4 from the third dispersion chamber 5.

[0043] The mixture M7 supplied from the first dispersion chamber 3 to the second dispersion chamber 4 collides with the blade 61 rotating immediately below the opening 55. By colliding with the blade 61, the mixture M7 is further dispersed. In particular, when the opening 55 is provided on a +Y-axis side with respect to a rotation axis O of the blade 61, and the blade 61 rotates counterclockwise when viewed from a-X side, the mixture M7 that passes through the opening 55 and moves downward collides with a front of the blade 61 that moves upward. Therefore, dispersion by the blade 61 is efficiently and favorably performed, and the dispersion effect of the mixture M7 is further enhanced. The mixture M7, which has been further dispersed by the blade 61, is supplied to the third dispersion chamber 5 through a large number of release ports 44 formed in the porous screen 43.

[0044] The third dispersion chamber 5 includes a housing 31 and a lower opening 312.

[0045] When the mixture M7 dispersed from the release ports 44 of the second dispersion chamber 4 enters the third dispersion chamber 5, the mixture M7 falls by gravity. In addition, in the third dispersion chamber 5, a flow of air toward the lower opening 312 is formed by the operation of a suction unit 193, and the mixture M7 falls on this flow. In this manner, the mixture M7 that has entered the third dispersion chamber 5 through the release ports 44 falls at an appropriate speed toward the web forming unit 19 by the gravity drop and the downward airflow.

[0046] As illustrated in FIGS. 1 and 2, the web forming unit 19 is an accumulating unit that accumulates the mixture M7 dispersed by the dispersing unit 18 and is a unit that performs the web forming step of forming a web M8 from the mixture M7. The web forming unit 19 includes a mesh belt 191, tension rollers 192, and the suction unit 193.

[0047] The mesh belt 191 is an endless belt, and the mixture M7 becomes the web M8 by accumulating on the mesh belt 191. The mesh belt 191 is hung around four tension rollers 192. The web M8 of the mesh belt 191 is transported downstream by the rotational driving of the tension rollers 192.

[0048] In addition, most of the mixture M7 on the mesh belt 191 has a size equal to or larger than the mesh openings of the mesh belt 191. As a result, the passage of the mixture M7 through the mesh belt 191 is restricted, and thus, the mixture M7 can accumulate on the mesh belt 191. In addition, since the mixture M7 is transported downstream together with the mesh belt 191 while accumulating on the mesh belt 191, the mixture M7 is formed as the web M8.

[0049] The suction unit 193 is a suction mechanism that sucks air from below the mesh belt 191. That is, by the operation of the suction unit 193, a flow of air in a-Z-axis direction is formed in the vicinity of an upper portion of the mesh belt 191 and in the vicinity of the lower opening 312 of the housing 31. As a result, the mixture M7 can be sucked onto the mesh belt 191, and thus the accumulation of the mixture M7 on the mesh belt 191 is promoted.

[0050] A pipe 246 is connected to the suction unit 193. A blower (not illustrated) is provided in the middle of the pipe 246. By the operation of the blower, a suction force can be generated in the suction unit 193.

[0051] The humidifying unit 232 is disposed downstream of the web forming unit 19. The humidifying unit 232 is constituted by an ultrasonic humidifier. As a result, moisture can be supplied to the web M8, and thus the amount of moisture in the web M8 is adjusted to an appropriate amount. By this adjustment, attraction of the web M8 to the mesh belt 191 due to an electrostatic force can be suppressed. As a result, the web M8 is easily peeled off from the mesh belt 191 at a position where the mesh belt 191 is folded back by the tension rollers 192.

[0052] The sheet forming unit 20 is disposed downstream of the humidifying unit 232. The sheet forming unit 20 is a unit that performs the sheet forming step of forming the sheet S from the web M8. The sheet forming unit 20 includes a pressing unit 201 and a heating unit 202.

[0053] The pressing unit 201 is a pressing roller, and the heating unit 202 is a heating roller. The pressing unit 201 and the heating unit 202 form a pair of rollers and function as heating and pressing rollers. The pair of heating and pressing rollers holds the web M8 between the rollers, and heats and presses the web M8. By the heating and pressing, the binder P1 is melted in the web M8, and the fibers are bound to each other through the melted binder P1. As a result, the sheet S is formed. Then, the sheet S is transported toward the cutting unit 21. One of the pair of heating and pressing rollers is a driving roller driven by the operation of a motor (not illustrated), and the other is a driven roller. Depending on the type of the binder P1, the fibers may be bound to each other by another method without heating.

[0054] The cutting unit 21 is disposed downstream of the sheet forming unit 20. The cutting unit 21 is a unit that performs the cutting step of cutting the sheet S. The cutting unit 21 includes a first cutter 211 and a second cutter 212.

[0055] The first cutter 211 cuts the sheet S in a direction intersecting with a transport direction of the sheet S, particularly a direction orthogonal to the transport direction.

[0056] The second cutter 212 is located downstream of the first cutter 211 and cuts the sheet S in a direction parallel to the transport direction of the sheet S. The cutting described above is performed to trim the width of the sheet S by removing unnecessary portions of both side end portions of the sheet S, that is, end portions in a +X direction and a-X direction.

[0057] Through such cutting with the first cutter 211 and the second cutter 212, the sheet S having a desired shape and a desired size is obtained. Then, the sheet S is further transported downstream and accumulated in the stock unit 22.

[0058] Each unit included in the sheet manufacturing apparatus 1 described above is electrically connected to the control unit 28. The operations of these units are controlled by the control unit 28.

[0059] The control unit 28 includes a central processing unit (CPU) 281 and a storage unit 282. The CPU 281 is, for example, an example of a processor capable of performing various determinations, various commands, and the like in accordance with various programs, and other processors may be used.

[0060] The storage unit 282 stores, for example, various programs, such as a program for manufacturing the sheet S, which are read into the CPU 281 and operated, various calibration curves, tables, and the like.

[0061] In addition, the control unit 28 may be built in the sheet manufacturing apparatus 1 or may be provided in an external device such as an external computer. In addition, for example, the external device may communicate with the sheet manufacturing apparatus 1 through a cable or the like, may communicate wirelessly, or may be connected to a network such as the Internet, for example, through the sheet manufacturing apparatus 1.

[0062] In addition, for example, the CPU 281 and the storage unit 282 may be integrated and configured as one unit, the CPU 281 may be built in the sheet manufacturing apparatus 1 while the storage unit 282 is provided in an external device such as an external computer, or the storage unit 282 may be built in the sheet manufacturing apparatus 1 while the CPU 281 is provided in an external device such as an external computer.

[0063] Next, the first rectifying plate 900 and the second rectifying plate 901 included in the supply pipe 8 will be described.

[0064] As illustrated in FIG. 3, the first rectifying plate 900 and the second rectifying plate 901 are disposed substantially perpendicular to the inner wall 910 of the second portion 82 that is a linear portion of the supply pipe 8. The second rectifying plate 901 is disposed so as to face the first rectifying plate 900 line-symmetrical with respect to a center line extending in the supply direction of the mixture M7 in the supply pipe 8. It can also be said that the first rectifying plate 900 and the second rectifying plate 901 are provided at an interval so as to overlap with a plane including the center line extending in supply direction of the mixture M7 in the supply pipe 8.

[0065] Since the supply pipe 8 includes the first rectifying plate 900 and the second rectifying plate 901, the airflow containing the mixture M7 flowing through the internal flow path 800 is rectified, and generation of a swirling flow is suppressed. By suppressing the generation of a swirling flow, uneven distribution of the mixture M7 is reduced, and the quality of the sheet S can be kept constant. In the present embodiment, rectifying means suppressing a swirling flow in the internal flow path 800.

[0066] As illustrated in FIG. 4, the first rectifying plate 900 and the second rectifying plate 901 are plate-shaped blades extending in the supply direction of the mixture M7 and each have a substantially trapezoidal shape in a Y-Z plane. Each of the first rectifying plate 900 and the second rectifying plate 901 includes a lower base 914 in contact with the inner wall 910 of the supply pipe 8, a first leg 912 located upstream in the supply direction of the mixture M7, a second leg 913 located downstream, and an upper base 915. Further, in the present embodiment, a length K1 of the lower base 914 of each of the first rectifying plate 900 and the second rectifying plate 901 is longer than a length J1 of the upper base 915 of each of the first rectifying plate 900 and the second rectifying plate 901, and a relationship K1>J1 is satisfied.

[0067] An angle formed by the lower base 914 of each of the first rectifying plate 900 and the second rectifying plate 901 and the first leg 912 is referred to as a first base angle A1, and an angle formed by the lower base 914 of each of the first rectifying plate 900 and the second rectifying plate 901 and the second leg 913 is referred to as a second base angle A2.

[0068] In the present embodiment, the first base angle A1 is 30, and the second base angle A2 is 60.

[0069] Depending on the angles of the first base angle A1 and the second base angle A2, the effect of suppressing the swirling flow generated in the internal flow path 800 changes. In addition, depending on the angles of the first base angle A1 and the second base angle A2, the mixture M7 may accumulate on surfaces of the first rectifying plate 900 and the second rectifying plate 901. When the mixture M7 accumulates on the surfaces, the accumulating mixture M7 may be peeled off later. The lumps that have peeled off are not completely dispersed by the dispersing unit 18, are supplied to the web forming unit 19, and adversely affect the quality of the sheet S.

[0070] FIG. 6 is a table illustrating the suppression effect of the swirling flow and the accumulation result of the mixture M7 when the angle of the first base angle A1 in each of the first rectifying plate 900 and the second rectifying plate 901 is changed. The significant figure of the first base angle A1 is one digit.

[0071] In the table, Poor indicates that a desired effect was not obtained, Good indicates that a desired effect was obtained, and Very amood indicates that an effect better than Good was obtained.

[0072] In the evaluation results illustrated in FIG. 6, good effects were obtained in both the suppression of the swirling flow and the difficulty of the accumulation of the mixture when the angle was 30 and 40. If the same effect can be obtained in the range of +5, the first base angle A1 is preferably 25 or more and less than 45, and more preferably 25 or more and less than 35.

[0073] FIG. 7 illustrates performance evaluation results when the angle of the second base angle A2 in each of the first rectifying plate 900 and the second rectifying plate 901 is changed. The significant figure of the second base angle A2 is one digit.

[0074] In the table, Poor indicates that a desired effect was not obtained, Good indicates that a desired effect was obtained, and Very Good indicates that an effect better than Good was obtained.

[0075] In the performance evaluation results of FIG. 7, when the angle was 60, 70, and 80, good effects were obtained in both the suppression of the swirling flow and the difficulty of the accumulation of the mixture. If the same effect can be obtained in the range of +5, the second base angle A2 is preferably 55 or more and less than 85, and more preferably 55 or more and less than 65. As illustrated in FIG. 4, an interval D between the upper base 915 of the first rectifying plate 900 and the upper base 915 of the second rectifying plate 901 is preferably 20 mm or more. Since the first rectifying plate 900 and the second rectifying plate 901 face each other at the interval D of 20 mm or more, it is possible to suppress the flow path resistance of the airflow containing the mixture M7 in the internal flow path 800 to be low and to prevent a decrease in the flow rate. In addition, even in a case where the mixture M7 accumulates on the surfaces of the first rectifying plate 900 and the second rectifying plate 901, it is possible to reduce blocking of the internal flow path 800.

[0076] As illustrated in FIG. 3, a relationship between the length K1 of the lower base 914 of each of the first rectifying plate 900 and the second rectifying plate 901 and a length L1 of the second portion 82 of the supply pipe 8 is more preferably K1/L1= or more and or less. By satisfying this relationship, it is possible to further suppress the swirling flow generated in the internal flow path 800.

[0077] The constituent material of the first rectifying plate 900 and the second rectifying plate 901 is not particularly limited, and examples thereof include various metal materials such as an iron-based alloy such as stainless steel, aluminum or an aluminum-based alloy, and copper or a copper-based alloy, and various resin materials. The resin materials may be hard or flexible.

[0078] The first rectifying plate 900 and the second rectifying plate 901 are connected to the inner wall 910 of the supply pipe 8 by a method such as welding, brazing, bonding with an adhesive, fitting, or caulking.

[0079] Although the present embodiment is based on the above-described configuration, the configuration can be partially changed or omitted without departing from the scope of the present disclosure. In addition, the present embodiment and modifications described below can be implemented in combination with each other as long as there is no technical contradiction. Hereinafter, modifications will be described.

[0080] In the above-described embodiment, the first rectifying plate 900 and the second rectifying plate 901 are disposed in the second portion 82 of the supply pipe 8, but the present disclosure is not limited to this configuration. For example, as illustrated in FIG. 5, the first rectifying plate 900 and the second rectifying plate 901 may be disposed in the first portion 81. In addition, the first rectifying plate 900 and the second rectifying plate 901 may be disposed in both the first portion 81 and the second portion 82.

[0081] In the above-described embodiment, the two rectifying plates of the first rectifying plate 900 and the second rectifying plate 901 are disposed, but a configuration in which only one rectifying plate is disposed may be adopted. In addition, in the configuration in which the rectifying plates are disposed in both the first portion 81 and the second portion 82, the number of rectifying plates disposed in the first portion 81 may be different from the number of rectifying plates disposed in the second portion 82.

[0082] The supply pipe 8 in the embodiment described above is not limited to a configuration provided in the sheet manufacturing apparatus 1, and may be provided in other manufacturing apparatuses. For example, the supply pipe 8 may be provided in a filter device for manufacturing a filter from inorganic fibers.