SHEET MANUFACTURING APPARATUS AND METHOD FOR MANUFACTURING SHEET

Description

The present application is based on, and claims priority from JP Application Serial Number 2024-088749, filed May 31, 2024, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a sheet manufacturing apparatus and a method for manufacturing a sheet.

2. Related Art

JP-A-2022-156155 discloses a configuration of a fiber structure manufacturing apparatus in which a cleaning roller rotates while being in contact with a felt roller so that bristles of a brush of the cleaning roller can scrape out paper dust from a felt fabric to clean it. Furthermore, generally, the paper dust can be removed from the cleaning roller by inserting a plate-shaped blade into the cleaning roller, and the paper dust can be discharged to the outside.

However, in the above-described method, the brush of the cleaning roller is readily damaged by the insertion of the plate-shaped blade into the cleaning roller, resulting in a problem of easy deterioration of the cleaning performance.

SUMMARY

A sheet manufacturing apparatus is a sheet manufacturing apparatus including an accumulation mechanism that accumulates a fiber material, a transport mechanism that transports the accumulated fiber material by using a transport belt, and a forming mechanism that forms the transported fiber material into a sheet. The transport mechanism includes a rotary brush that cleans a surface of the transport belt, a comb that has a front end inserted into the rotary brush and a base located outside the rotary brush, a paddle that is located on an opposite side of the comb from the rotary brush and sweeps a surface of the comb at a position where the paddle does not come in contact with the rotary brush.

A method for manufacturing a sheet includes accumulating a fiber material, transporting the accumulated fiber material by using a transport belt, and forming the transported fiber material into a sheet. The method uses a rotary brush that comes in contact with a surface of the transport belt, a comb that has a front end inserted into the rotary brush, and a paddle that is located on an opposite side of the comb from the rotary brush and sweeps a surface of the comb at a position where the paddle does not come in contact with the rotary brush. The method includes rotating the transport belt and the rotary brush to move a residual fiber attached to the transport belt to the comb via the rotary brush, and sweeping a surface of the comb with the paddle to remove the residual fiber from the comb.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a configuration of a sheet manufacturing apparatus.

FIG. 2 is a magnified perspective view illustrating a portion II of the sheet manufacturing apparatus illustrated in FIG. 1.

FIG. 3 is a magnified perspective view illustrating a portion III of the sheet manufacturing apparatus illustrated in FIG. 2.

FIG. 4 is a side view illustrating a configuration of a collection mechanism illustrated in FIG. 2.

FIG. 5 is a magnified side view illustrating a configuration of a portion V of the collection mechanism illustrated in FIG. 4.

FIG. 6 is a magnified side view illustrating a portion VI of the collection mechanism illustrated in FIG. 5.

FIG. 7 is a perspective view illustrating a configuration of a paddle.

FIG. 8 is a perspective view illustrating a configuration around the collection mechanism.

FIG. 9 is a plan view illustrating a configuration of a comb which is a portion of the paddle.

FIG. 10 is a magnified view illustrating a portion X of the comb illustrated in FIG. 9.

FIG. 11 is a magnified perspective view illustrating a portion XI of the comb illustrated in FIG. 9.

FIG. 12A is a side view illustrating a method for collecting a residual fiber.

FIG. 12B is a side view illustrating a method for collecting a residual fiber.

FIG. 12C is a side view illustrating a method for collecting a residual fiber.

FIG. 12D is a side view illustrating a method for collecting a residual fiber.

DESCRIPTION OF EMBODIMENTS

The configuration of a sheet manufacturing apparatus 1 will be described below with reference to the drawings. In each of the following drawings, three axes orthogonal to each other are referred to as an X axis, a Y axis, and a Z axis. A direction along the X axis is referred to as an “X direction”, a direction along the Y axis is referred to as a “Y direction”, and a direction along the Z axis is referred to as a “Z direction”. An arrow direction is referred to as a + direction, and a direction opposite to the + direction is referred to as a—direction. A view from the +Z direction or the −Z direction is referred to as a plan view or planar. In addition, in the sheet manufacturing apparatus 1, a leading side in a transport direction of a raw material, a web, a sheet, and the like may be referred to as a downstream side, and a trailing side in the transport direction may be referred to as an upstream side.

First, a configuration of the sheet manufacturing apparatus 1 will be described with reference to FIG. 1. The sheet manufacturing apparatus 1 manufactures

sheets from a material containing a fiber (hereinafter referred to as a fiber material). In the following, used paper C will be described as an example of the fiber material, but the fiber material may be a mass of other kinds of fibers, such as cotton, wool, polyester, and a mixture thereof. The sheet manufacturing apparatus 1 regenerates sheets from pieces of paper, such as used paper, in a dry process. The sheet manufacturing apparatus 1 is not limited to a dry type apparatus and may be a wet type apparatus. In the present specification, the dry type means that the process is not performed in a liquid, but in air, such as the atmosphere.

As illustrated in FIG. 1, the sheet manufacturing apparatus 1 includes a first unit group 101, a second unit group 102, and a third unit group 103. The first unit group 101, the second unit group 102, and the third unit group 103 are supported by frames (not illustrated). In FIG. 1, directions in which the used paper C, sheets P3, slit pieces S, unnecessary scrap pieces, and the like are transported are indicated by white arrows.

The sheet manufacturing apparatus 1 manufactures sheets P3 from the used paper C, which is a fiber material. In the sheet manufacturing apparatus 1, the first unit group 101, the third unit group 103, and the second unit group 102 are arranged from the −Y direction to the +Y direction, in a side view from the −X direction.

The used paper C is transported from the first unit group 101 to the second unit group 102 through a pipe 21 that extends across the third unit group 103. The used paper C is subjected to defibration or the like in the second unit group 102 to be separated into fibers and then is mixed with a binding material or the like to become a mixture.

The mixture is transported to the third unit group 103 through a pipe 24. The mixture is made into a web W in the third unit group 103 and then is formed into a strip-shaped sheet P1. The strip-shaped sheet P1 is cut into the sheets P3 in the first unit group 101.

The first unit group 101 includes a buffer tank 13, a fixed-quantity supply unit 15, a merging section 17, and the pipe 21. In the first unit group 101, these components are arranged in the above order from the upstream side toward the downstream side. The first unit group 101 also includes a first cutting unit 81, a second cutting unit 82, a tray 84, and a shredding unit 86.

The first cutting unit 81 and the second cutting unit 82 cut the strip-shaped sheet P1 into the sheets P3 having a predetermined shape. Furthermore, the first unit group 101 includes a water supply unit 67. The water supply unit 67 is a water storage tank. The water supply unit 67 supplies water for humidification through a water supply pipe (not illustrated) to each of a first humidifying unit 65 and a second humidifying unit 66, which are humidifying units (described later).

The used paper C is put into the buffer tank 13 through a raw material charging port 11. The used paper C contains fibers such as cellulose and is, for example, a piece of shredded used paper. Humidified air is supplied into the buffer tank 13 from the second humidifying unit 66 of the third unit group 103.

The used paper C to be defibrated is temporarily stored in the buffer tank 13 and is then transported to the fixed-quantity supply unit 15 according to the operation of the sheet manufacturing apparatus 1. The sheet manufacturing apparatus 1 may include a shredder for shredding the used paper C or the like on the upstream side of the buffer tank 13.

The fixed-quantity supply unit 15 includes a measuring instrument 15a and a supply mechanism (not illustrated). The measuring instrument 15a measures the weight of the used paper C. The supply mechanism supplies the used paper C weighed by the measuring instrument 15a to the downstream merging section 17. That is, the fixed-quantity supply unit 15 weighs a predetermined mass of the used paper C each time by using the measuring instrument 15a and supplies the used paper C to the downstream merging section 17 by using the supply mechanism.

In the merging section 17, shredded pieces of the slit pieces S supplied from the shredding unit 86 are merged and mixed with the used paper C supplied from the fixed-quantity supply unit 15. The slit pieces S and the shredding unit 86 will be described later. The used paper C mixed with the shredded pieces flows from the merging section 17 into the pipe 21. Through the pipe 21, the used paper C is transported from the first unit group 101 to the second unit group 102 using airflow generated by a blower (not illustrated).

The second unit group 102 includes a defibrating unit 30, which is a dry defibrator, a separation unit 40, a pipe 23, a mixing unit 91, and a pipe 24. In the second unit group 102, these components are arranged in the above order from the upstream side to the downstream side. The second unit group 102 also includes a collection unit 95, a compressor 97, a power supply unit 99, a pipe 25 connected to the separation unit 40, and an airflow pipe 29.

The used paper C transported through the pipe 21 flows into the defibrating unit 30. The defibrating unit 30 defibrates the used paper C, which is a fiber material, in a dry process to generate a defibrated material containing fibers. A known defibrating mechanism is applicable as the defibrating unit 30. In the present embodiment, a defibrating mechanism including a rotary blade is used as the defibrating unit 30. The defibrating mechanism generates fibers by shredding and defibrating the used paper C by using the rotary blade. The used paper C becomes a defibrated material containing fibers when the entangled fibers included in the used paper C are untangled by the defibrating unit 30, and then is transported to the separation unit 40.

The separation unit 40 sorts the defibrated fibers. Specifically, the separation unit 40 removes components contained in the fibers that are unnecessary for the manufacture of the sheet P3. That is, the separation unit 40 sorts the fibers into relatively long fibers and relatively short fibers. The relatively short fibers, which may lower the strength of the sheet P3, are selected and removed by the separation unit 40. The separation unit 40 also removes impurities, such as coloring materials and additives contained in the used paper C.

In the present embodiment, a disc-type separation mechanism including a separation filter is used as the separation unit 40. The separation mechanism sorts out and separates relatively short fibers and impurities that can pass through the separation filter from relatively long fibers that cannot pass through the separation filter. The relatively long fibers, which are defibrated fibers, are used as the material of the web W. Humidified air is supplied into the separation unit 40 from the second humidifying unit 66 of the third unit group 103.

The relatively short fibers and the like are removed from the defibrated fibers at the separation unit 40. Then, the defibrated fibers are transported to the mixing unit 91 through the pipe 23 by airflow generated by a blower (not illustrated) located at the distal end of the airflow pipe 29. Unnecessary components such as relatively short fibers and impurities are discharged from the pipe 25 to the collection unit 95.

The mixing unit 91 mixes the fibers with a binding material and the like in air to form a mixture. Although not illustrated, the mixing unit 91 includes a flow path through which fibers are transported, a fan, a hopper, a feeding pipe, and a valve. The mixture flows from the mixing unit 91 into the pipe 24.

The fan of the mixing unit 91 mixes the binder and the like in the air to form a mixture while transporting the fibers downstream by the generated airflow. The collection unit 95 includes a filter (not illustrated). The filter filters out unnecessary components, such as relatively short fibers transported through the pipe 25 by the airflow.

The compressor 97 generates compressed air. The filter may be clogged with fine particles or the like of the unnecessary components. The compressed air generated by the compressor 97 can be blown onto the filter to blow off attached particles and clean the filter.

The power supply unit 99 includes a power supply device (not illustrated) that supplies electric power to the sheet manufacturing apparatus 1 and a control unit 5. The power supply unit 99 distributes electric power supplied from an external source to each of the components of the sheet manufacturing apparatus 1.

The control unit 5 includes a central processing unit (CPU) and a memory including a random-access memory (RAM), a read only memory (ROM), and the like. The memory stores various programs for controlling the sheet manufacturing apparatus 1. The control unit 5 may include dedicated hardware (application specific integrated circuit: ASIC) that executes at least one of various processes. That is, the control unit 5 may be configured as one or more processors that operate in accordance with a computer program (software), one or more dedicated hardware circuits, such as an ASIC, or a circuit including a combination thereof.

The third unit group 103 accumulates and compresses the mixture containing fibers to form the strip-shaped sheet P1, which is recycled paper. The third unit group 103 includes an accumulation mechanism 50, a transport mechanism 62, a first humidifying unit 65, an air ejection unit 200, a second humidifying unit 66, a drainage unit 68, and a forming mechanism 70.

In the third unit group 103, the accumulation mechanism 50, the first transport unit 61, the transport mechanism 62, the first humidifying unit 65, and the forming mechanism 70 are arranged in this order from the upstream side to the downstream side. The air ejection unit 200 is located in the transport mechanism 62 and located at the downstream end of the transport path of the web W in the transport mechanism 62. The second humidifying unit 66 is located below the first humidifying unit 65.

The accumulation mechanism 50 forms the web W by accumulating the mixture, which was generated from the defibrated material, by using airflow and gravity. The accumulation mechanism 50 includes a drum member 53, a blade member 55 installed in the drum member 53, a housing 51 that houses the drum member 53, and a first suction unit 59. The mixture is taken into the drum member 53 through the pipe 24.

The first transport unit 61 is located below the accumulation mechanism 50. The first transport unit 61 includes an accumulation belt 61a and five rollers on which the accumulation belt 61a is supported in a tensioned state. The first suction unit 59 faces the drum member 53 with the accumulation belt 61a interposed therebetween in the direction along the Z axis.

The blade member 55 is located inside the drum member 53. The blade member 55 is rotationally driven by a motor (not illustrated). The drum member 53 is a semi-cylindrical sieve. The drum member 53 has a mesh having the function of a sieve on a side surface facing downward. The drum member 53 allows particles such as the fibers or the mixture smaller than the mesh openings of the sieve to pass therethrough from the inside to the outside.

The mixture is discharged to the outside of the drum member 53 while being stirred by the rotating blade member 55 in the drum member 53. Humidified air is supplied to the inside of the drum member 53 from the second humidifying unit 66.

The first suction unit 59 is located below the drum member 53. The first suction unit 59 suctions air from the housing 51 through multiple holes in the accumulation belt 61a. This generates airflow which accumulates the mixture on the accumulation belt 61a.

The multiple holes in the accumulation belt 61a allow air to pass therethrough but do not easily allow the fibers, the binding material, and the like contained in the mixture to pass therethrough. Accordingly, the mixture discharged to the outside of the drum member 53 is suctioned downward together with the air. The first suction unit 59 is a known suction device such as a suction fan. The mixture is dispersed in the air inside the housing 51 and is accumulated on the upper surface of the accumulation belt 61a by gravity and the airflow generated by the first suction unit 59 to form the web W.

The accumulation belt 61a is an endless belt and is supported by five rollers in a tensioned state. The accumulation belt 61a is rotated counterclockwise in FIG. 1 by rotation of the rollers. Accordingly, the mixture is continuously accumulated on the accumulation belt 61a to form the web W. The web W contains a relatively large amount of air and is soft and swollen. The first transport unit 61 transports the formed web W downstream by rotation of the accumulation belt 61a.

The transport mechanism 62 transports the web W on the downstream side of the first transport unit 61, instead of the first transport unit 61. The transport mechanism 62 separates the web W from the upper surface of the accumulation belt 61a and transports the web W toward the forming mechanism 70. The transport mechanism 62 is located above the transport path of the web W and slightly upstream of the starting point of the return side of the accumulation belt 61a. The +Y direction portion of the transport mechanism 62 and the −Y direction portion of the accumulation belt 61a partially overlap each other in the vertical direction.

The transport mechanism 62 includes the accumulation belt 61a, a transport belt 62a, four rollers 63 (see FIG. 2), a second suction unit 62b, and a motor and a gear for driving a belt (not illustrated). The accumulation belt 61a is included in both the accumulation mechanism 50 and the transport mechanism 62. The transport belt 62a has multiple holes through which air passes. The transport belt 62a is supported by the four rollers 63 in a tensioned state and is rotated in a clockwise direction, which is a first direction, in FIG. 1 by rotation of the rollers 63.

The second suction unit 62b is located along the transport path of the web W in the transport mechanism 62 and is located above the transport belt 62a. The second suction unit 62b suctions air upward through the multiple holes in the transport belt 62a. Accordingly, a first surface, which is an upper surface, of the web W is held by suction on a lower surface of the transport belt 62a. When the transport belt 62a in this state is rotated, the web W is transported downstream while being held by suction on the transport belt 62a. In other words, the transport belt 62a transports the web W while being in contact with the first surface of the web W. The second suction unit 62b is a known suction device, such as a suction fan.

The first humidifying unit 65 humidifies the web W containing fibers accumulated at the accumulation mechanism 50 of the third unit group 103. Specifically, the first humidifying unit 65 is, for example, a mist humidifier, and humidifies the web W transported by the transport mechanism 62 by supplying the mist M from below the web W. The first humidifying unit 65 is located below the transport mechanism 62 and faces the web W transported by the transport mechanism 62 in the direction along the Z axis. For example, a known humidifier such as an ultrasonic humidifier can be used as the first humidifying unit 65.

When the web W is humidified with the mist M, the function of the binding material contained in the web W is promoted, increasing the strength of the sheet P3. Furthermore, since the web W is humidified from below, droplets derived from the mist M do not fall onto the web W. Furthermore, since the web W is humidified from the opposite side from the first surface of the web W, which comes in contact with the transport belt 62a, adhesion of the web to the transport belt 62a can be reduced. The transport mechanism 62 transports the web W toward the forming mechanism 70.

The air ejection unit 200 is included in the transport mechanism 62 and located downstream of the second suction unit 62b. Although not illustrated, the air ejection unit 200 includes a compressed air tank and an ejection nozzle. The compressed air tank supplies compressed air to the ejection nozzle. The air ejection unit 200 ejects compressed air downward through the ejection nozzle to the web W. The compressed air tank stores compressed air supplied from, for example, a compressor for the air ejection unit 200 (not illustrated).

The ejection nozzle is an elongated opening extending in the direction along the X axis. The ejection nozzle faces the web W, which is transported by the transport belt 62a, in the direction along the Z axis. The compressed air ejected from the air ejection unit 200 passes through the transport belt 62a and hits the first surface of the web W that is held by suction on the lower surface of the transport belt 62a. At this time, since the ejection nozzle is longer than the web W in the direction along the X axis, the compressed air ejected from the ejection nozzle is blown to the entire widthwise area of the web W.

In this way, the web W is separated from the transport belt 62a. The compressed air is ejected by the air ejection unit 200 when the downstream end of the web W reaches a region facing the air ejection unit 200. Then, after the end of the web W is separated from the transport belt 62a, the end of the web W is bent, or the end of the web W is folded. Then, the web W is transported from the transport mechanism 62 to the forming mechanism 70.

A collection unit 1000 (see FIGS. 2 and 4) for collecting residual fibers PP (see FIG. 4) attached to the transport belt 62a is located next to the transport belt 62a. Specifically, as described above, the transport belt 62a has the multiple holes through which air is suctioned by the second suction unit 62b, and thus the remaining residual fibers PP are attached to the transport belt 62a. This may cause defects, such as failing to vacuum, and to avoid such defects, the residual fibers PP attached to the transport belt 62a are removed. Specific configurations and methods will be described later.

The forming mechanism 70 includes a pressing roller pair 700 including a first roller 71 and a second roller 72. The forming mechanism 70 allows the web W to pass between the rollers of the pressing roller pair 700 to form a strip-shaped sheet P1 from the web W.

The first roller 71 and the second roller 72 are paired and each have a substantially cylindrical shape. The rotation axis of the first roller 71 and the rotation axis of the second roller 72 extend along the X axis. The first roller 71 is located substantially below the transport path of the web W, and the second roller 72 is located substantially above the transport path of the web W. The first roller 71 and the second roller 72 rotate in proximity to each other while the strip-shaped sheet P1 is being formed from the web W.

In the direction along the X axis, the first roller 71 and the second roller 72 are longer than the web W, that is, the width of the web W. Thus, the web W is reliably pinched between the first roller 71 and the second roller 72.

The web W is pressed when passing between the first roller 71 and the second roller 72. The first roller 71 has a built-in electric heater and has the function of increasing the temperature of the roller surface. Like the first roller 71, the second roller 72 preferably has the function of increasing the temperature of the roller surface with an electric heater.

The first roller 71 is rotationally driven by a stepping motor (not illustrated). The second roller 72 is a driven roller which is not driven by a motor but is rotated by rotation of the first roller 71. Thus, the second roller 72 rotates in the opposite direction to the first roller 71 in a side view from the −X direction.

The web W is sent downstream while being heated and pressed between the first roller 71 and the second roller 72. That is, the web W continuously passes through the forming mechanism 70 and is press-formed while being heated. The use of the first roller 71 and the second roller 72 as a pair of forming members enables efficient heating and pressing of the web W.

When the web W in a soft state with a relatively high air content passes through the forming mechanism 70, the amount of air contained decreases and the density of the web W increases. Then, the fibers are bound to each other by the binding material and formed into the strip-shaped sheet P1. The strip-shaped sheet P1 is transported to the first unit group 101 by transport rollers (not illustrated).

The second humidifying unit 66 is located below the first humidifying unit 65. A known evaporative humidifier can be used as the second humidifying unit 66.

The second humidifying unit 66 humidifies a predetermined region of the sheet manufacturing apparatus 1. The predetermined region is one or more of the buffer tank 13, the separation unit 40, and the inside of the drum member 53 of the accumulation mechanism 50. Specifically, humidified air is supplied from the second humidifying unit 66 to the above-described region through multiple pipes (not illustrated). The humidified air reduces electrostatic charging of the used paper C, fibers, and the like in each of the above-described components, reducing adhesion of the used paper C, fibers, and the like to the members due to static electricity.

The drainage unit 68 is a drainage tank. The drainage unit 68 is used for the first humidifying unit 65, the second humidifying unit 66, and the like to collect and store old moisture. The drainage unit 68 can be detached from the sheet manufacturing apparatus 1 as necessary to discard the stored water.

The strip-shaped sheet P1 transported to the first unit group 101 reaches the first cutting unit 81. The first cutting unit 81 cuts the strip-shaped sheet P1 in a direction intersecting the transport direction, for example, in the direction along the X axis. The strip-shaped sheet P1 is cut into cut sheets P2 by the first cutting unit 81. The cut sheets P2 are transported from the first cutting unit 81 to the second cutting unit 82.

The second cutting unit 82 cuts the cut sheet P2 in the transport direction, for example, in the direction along the Y axis. Specifically, the second cutting unit 82 cuts both end portions in the X axis direction of the cut sheet P2. Accordingly, the cut sheet P2 becomes a sheet P3 having a predetermined shape, such as an A4 size or an A3 size.

When the cut sheet P2 is cut into the sheet P3 in the second cutting unit 82, the slit pieces S that are scrap pieces are generated. The slit pieces S are transported substantially in the −Y direction to the shredding unit 86, which is a shredder. The shredding unit 86 shreds the slit pieces S into shredded pieces, and the shredded pieces are supplied to the merging section 17. A mechanism for weighing the shredded pieces of the slit piece S and supplying the shredded pieces to the merging section 17 may be installed between the shredding unit 86 and the merging section 17.

The sheets P3 are transported substantially upward and stacked in the tray 84. In this way, the sheets P3 are manufactured by the sheet manufacturing apparatus 1. The sheet P3 can be used, for example, as a substitute for copy paper or the like.

Next, the configuration of the transport mechanism 62 will be described with reference to FIGS. 2 to 7.

As illustrated in FIGS. 2 to 5, the transport mechanism 62 includes the transport belt 62a, the multiple rollers 63, and the collection unit 1000. The transport belt 62a is supported by the rollers 63 in a tensioned state and is configured to allow air to pass therethrough. The transport belt 62a is configured to be rotationally driven by rotation of the rollers 63.

The collection unit 1000 is located adjacent to the transport belt 62a. The collection unit 1000 includes a rotary brush 1100, a comb 1200, a paddle 1300, a collection container 1400, and a paper dust transport pipe 1500 as a pipe.

The rotary brush 1100 is configured to clean a surface of the transport belt 62a and is located so as to be in rotational contact with the +Y direction side of the transport belt 62a. As described above, the transport belt 62a rotates in a clockwise direction, which is the first direction. That is, the transport belt 62a at the +Y direction side rotates from top (+Z direction) to bottom (−Z direction).

The rotary brush 1100 rotates, for example, in a clockwise direction, which is the first direction. That is, the rotary brush 1100 at the side in contact with the transport belt 62a rotates from bottom (−Z direction) to top (+Z direction).

In this way, since the rotary brush 1100 rotates in the direction against the rotation direction of the transport belt 62a, the residual fibers PP attached to the transport belt 62a can be readily removed. The rotary brush 1100 is formed of, for example, a napped material.

As illustrated in FIGS. 3 and 5, the comb 1200 is inserted from below the rotary brush 1100. Specifically, as illustrated in FIG. 5, the comb 1200 is fixed in such a manner that a front end 1210 of the comb 1200 is located at a position corresponding to about half the thickness W1 of the brush 1110 of the rotary brush 1100. A base 1220 of the comb 1200 is located at a position not in contact with the rotary brush 1100 and is fixed at a position outside the rotary brush 1100.

In this way, since the comb 1200 is inserted in the direction against the rotation direction of the rotary brush 1100, the residual fibers PP attached to the rotary brush 1100 can be scraped out by the comb 1200. Some of the scraped residual fibers PP just fall from the comb 1200, and some of the scraped residual fibers PP gather on the outer side of the rotary brush 1100 of the comb 1200, in other words, on the side closer to the base 1220 than to the region of the comb 1200 inserted into the rotary brush 1100.

The comb 1200 is formed of a metal material and is grounded. Examples of the metal material include stainless steel (SUS). As described above, since the comb 1200 formed of a metal material is grounded, even when static electricity is generated by repeated rotational contact between the comb 1200 and the rotary brush 1100, the static electricity can be released. This can reduce the possibility that the collected residual fibers PP will attach to the rotary brush 1100 again.

As illustrated in FIG. 6, the paddle 1300 sweeps and removes the residual fibers PP accumulated on the surface of the base 1220 of the comb 1200. The paddle 1300 is located on an opposite side of the comb 1200 from the rotary brush 1100 and is located at a position where the paddle 1300 does not come in contact with the rotary brush 1100.

The paddle 1300 includes a fixed shaft 1310, fixed plates 1320, and blades 1330. The paddle 1300 rotates in a counterclockwise direction, which is a second direction, about the fixed shaft 1310. Two fixed plates 1320 are located around the fixed shaft 1310 and face each other. The blades 1330 are attached to the respective fixed plates 1320. Specifically, the blade 1330 is pinched and fixed between the fixed shaft 1310 and the fixed plate 1320.

The blade 1330 is located such that a front end 1331 protrudes from the fixed plate 1320 in an outer circumferential direction of the fixed shaft 1310. With this arrangement, when the paddle 1300 rotates, the residual fibers PP accumulated on the base 1220 of the comb 1200 can be removed by the front end 1331 of the blade 1330.

In addition, since the paddle 1300 rotates counterclockwise, it is possible to move the residual fibers PP accumulated on the base 1220 of the comb 1200 in a direction away from the rotary brush 1100, reducing the possibility that the residual fibers PP will attach to the rotary brush 1100 again.

As illustrated in FIG. 6, the paddle 1300 is located at a position where the paddle 1300 does not touch the surface of the comb 1200 when rotated. In this configuration, the paddle 1300 is located such that the paddle 1300 does not touch the surface of the comb 1200. This can reduce the possibility that the residual fibers PP accumulated on the base 1220 (see FIG. 5) of the comb 1200 will be caught between the comb 1200 and the paddle 1300 and become difficult to collect.

As illustrated in FIG. 7, the length L3 of the portion of the blade 1330 protruding from the fixed plate 1320 is, for example, 2 mm. The width W4 of the blade 1330 is, for example, 0.5 mm. The material of the blade 1330 is, for example, polyethylene terephthalate (PET), which is elastically deformable.

As illustrated in FIG. 2, the collection container 1400 is located at the lower side of the collection unit 1000. Specifically, the collection container 1400 is located below, or in a vertical direction of, the paddle 1300. The collection container 1400, which is located below the paddle 1300, can receive the residual fibers PP fell downward from the paddle 1300. This can reduce the possibility that the residual fibers PP swept out by the paddle 1300 will scatter around.

Furthermore, a collection screw 1410 is rotatably located in the collection container 1400. The rotation of the collection screw 1410 moves the collected residual fibers PP from the rear side to the front side of the collection container 1400, in other words, from the +X direction to the −X direction. The residual fibers PP collected at the front side are sent to the pipe 21 again through the paper dust transport pipe 1500 and reach the defibrating unit 30. Thus, the residual fibers PP are not discarded, and sheets can be produced again from the step at the defibrating unit 30.

As illustrated in FIG. 8, the length of the rotary brush 1100 is substantially the same as the length of the paddle 1300. As illustrated in FIG. 8, the length L1 of the paddle 1300 is, for example, 370 mm. In this way, since the length L1 of the paddle 1300 is substantially the same as the length of the rotary brush 1100, all the residual fibers PP on the transport belt 62a scraped out by the rotary brush 1100 can fall into the collection container 1400.

Next, the configuration of the comb 1200 will be described with reference to FIGS. 9 to 11.

As illustrated in FIG. 9, the comb 1200 has substantially the same length as the rotary brush 1100. That is, as described above, the length is substantially the same as the length L1 of the paddle 1300. The comb 1200 has multiple bars 1230.

As illustrated in FIG. 10, the length L2 of the bars 1230 is, for example, 12 mm. The interval W2 between adjacent bars 1230 is, for example, 0.7 mm. The width W3 of the bar 1230 is, for example, 0.7 mm.

As illustrated in FIG. 11, the radius R of the front end 1210a of the bar 1230 that is located at the middle of the comb 1200 is, for example, R 0.35 mm. The radius R of a front end 1210b of the bar 1230 that is located at each end of the comb 1200 is, for example, R 0.625 mm. That is, the bar 1230 that is located at each end has a thickness W4 of 1.25 mm.

The comb 1200 having the multiple bars 1230 is formed by, for example, an etching process. Thus, spaces having a large depth from the front end 1210a to the bottom can be formed. This can provide a region that does not come in contact with the rotary brush 1100, and the residual fibers PP can be accumulated in this region.

Furthermore, since the front ends 1210a and 1210b of the bars 1230 are formed by the etching process and electrolytic polishing process, the radius R can be made larger, and wear of the rotary brush 1100 can be reduced.

Next, a method for collecting the residual fiber PP, which is a portion of the sheet manufacturing method, will be described with reference to FIGS. 12A to 12D.

In a step illustrated in FIG. 12A, the residual fiber PP removed from the transport belt 62a and attached to the brush of the rotary brush 1100 is transported clockwise.

In a step illustrated in FIG. 12B, the front end 1210 of the comb 1200 is inserted into the rotary brush 1100, and the residual fiber PP is scraped out by the comb 1200. Specifically, the front end 1210 of the comb 1200 is inserted in the direction against the rotation direction of the rotary brush 1100, and furthermore, the front end 1210 of the comb 1200 is inserted to about a half of the thickness W1 of the brush 1110 of the rotary brush 1100, so that the front end can come in contact with the residual fiber PP attached to the rotary brush 1100.

Next, the transport belt 62a and the rotary brush 1100 are rotated clockwise, and the residual fibers PP attached to the transport belt 62a are swept and gathered at the base 1220 of the comb 1200 via the rotary brush 1100. In this way, since the rotary brush 1100 rotates clockwise, the residual fiber PP at the front end 1210 of the comb 1200 is gathered to the base 1220.

In a step illustrated in FIG. 12C, the paddle 1300 is rotated counterclockwise to sweep the surface of the comb 1200 and remove the residual fiber PP gathered at the base 1220 of the comb 1200 from the comb 1200. Specifically, the residual fiber PP accumulated on the comb 1200 is swept out to the outside of the comb 1200 by the blade 1330 of the paddle 1300. The blade 1330 rotates at a position where the blade does not come in contact with the surface of the comb 1200. The base 1220 of the comb 1200 is away from the boundary between the rotary brush 1100 and the comb 1200 by, for example, 4 mm. Thus, the front end 1331 of the blade 1330 can sweep out the residual fiber PP accumulated on the base 1220 of the comb 1200 without coming in contact with the rotary brush 1100.

Then, as illustrated in FIG. 12D, since the blades 1330 rotate counterclockwise, the residual fiber PP can be blown off in a direction away from the rotary brush 1100. The blown residual fibers PP fall below the paddle 1300 as described above and are collected in the collection container 1400 (see FIG. 2).

As described above, since the comb 1200 is inserted into the rotary brush 1100, damage to the rotary brush 1100 can be reduced, for example, compared to a case where a plate-shaped blade is inserted into the rotary brush 1100, and thus deterioration of the cleaning performance of the rotary brush 1100 can be reduced. Furthermore, the paddle 1300 sweeping the surface of the comb 1200 can remove the residual fibers PP accumulated on the surface of the comb 1200 from the comb 1200.

Furthermore, the rotation speed of the transport belt 62a and the rotation speed of the front end of the rotary brush 1100 are, for example, the same to prevent the residual fibers PP from accumulating on the rotary brush 1100. The rotation speed of the rotary brush 1100 is preferably faster than the rotation speed of the transport belt 62a.

As described above, the sheet manufacturing apparatus 1 according to this embodiment includes the accumulation mechanism 50 that accumulates a fiber material, the transport mechanism 62 that transports the accumulated fiber material by using the transport belt 62a, and the forming mechanism 70 that forms the transported fiber material into a sheet. The transport mechanism 62 includes the rotary brush 1100 that cleans a surface of the transport belt 62a, the comb 1200 that has the front end 1210 inserted into the rotary brush 1100 and the base 1220 located outside the rotary brush 1100, and the paddle 1300 that is located on an opposite side of the comb 1200 from the rotary brush 1100 and sweeps a surface of the comb 1200 at a position where the paddle 1300 does not come in contact with the rotary brush 1100.

According to this configuration, since the comb 1200 is inserted into the rotary brush 1100, damage to the rotary brush 1100 can be reduced, for example, compared to a case where a plate-shaped blade is inserted into the rotary brush 1100, and thus deterioration of the cleaning performance of removing the residual fibers PP attached to the rotary brush 1100 can be reduced. Furthermore, the paddle 1300 sweeping the surface of the comb 1200 can remove the residual fibers PP accumulated on the surface of the comb 1200 from the comb 1200.

In addition, since the residual fibers PP attached to the transport belt 62a are removed, it is possible to reduce deterioration of the quality of the sheet, which is caused by unremoved residual fibers PP attached to the sheet as in the related art in which the cleaning performance of removing the residual fibers PP is deteriorated. Furthermore, the cleaning performance can be maintained, and the maintenance period can be extended.

In the sheet manufacturing apparatus 1 of the present embodiment, the comb 1200 may be inserted from below the rotary brush 1100. According to this configuration, since the comb 1200 is inserted from below the rotary brush 1100, in other words, for example, in the direction against the rotation direction of the rotary brush 1100, the residual fibers PP attached to the rotary brush 1100 can be gathered at the base 1220 of the comb 1200.

In addition, in the sheet manufacturing apparatus 1 of the embodiment, the transport belt 62a and the rotary brush 1100 may rotate in the first direction, and the paddle 1300 may rotate in the second direction opposite to the first direction. According to this configuration, since the transport belt 62a and the rotary brush 1100, which comes in contact with the transport belt 62a, rotate in the same first direction, that is, come into contact with each other in opposite directions at the point of contact, the residual fibers PP attached to the transport belt 62a can be readily removed by using the rotary brush 1100. In addition, since the paddle 1300 rotates in the second direction, the residual fibers PP accumulated on the base 1220 of the comb 1200 can be swept out in a direction away from the rotary brush 1100, reducing the possibility that the residual fibers PP will attach to the rotary brush 1100 again.

In addition, in the sheet manufacturing apparatus 1 of the embodiment, the paddle 1300 may be located at a position where the paddle 1300 does not touch a surface of the comb 1200. According to this configuration, the paddle 1300 is located so as not to touch a surface of the comb 1200, and thus the residual fibers PP accumulated on the base 1220 of the comb 1200 can be prevented from being caught between the comb 1200 and the paddle 1300, which makes the removal difficult.

In addition, the sheet manufacturing apparatus 1 of the embodiment may include the collection container 1400 that is located in a vertical direction of the comb 1200 and collects the residual fiber PP swept out by the paddle 1300. According to this configuration, the presence of the collection container 1400 can reduce the possibility that the removed residual fibers PP will be scattered around.

In addition, the sheet manufacturing apparatus 1 of the embodiment may further include the defibrating unit 30 that defibrates used paper. The collection container 1400 is connected to the defibrating unit 30 by the paper dust transport pipe 1500, and the residual fiber PP collected by the collection container 1400 is sent to the defibrating unit 30 through the paper dust transport pipe 1500. According to this configuration, the collection container 1400 and the defibrating unit 30 are connected by the paper dust transport pipe 1500, and the collected residual fibers PP are sent to the defibrating unit 30. Thus, the residual fibers PP are not discarded, and sheets can be produced again from the step at the defibrating unit 30.

Furthermore, in the sheet manufacturing apparatus 1 of the embodiment, the comb 1200 may be formed of a metal material and may be grounded. According to this configuration, since the comb 1200 formed of a metal material is grounded, even when static electricity is generated by repeated rotational contact between the comb 1200 and the rotary brush 1100, the static electricity can be released. This can reduce the possibility that the collected residual fibers PP will attach to the rotary brush 1100 again.

In addition, the method for manufacturing a sheet of the present embodiment is a method for manufacturing a sheet that uses the accumulation mechanism 50 that accumulates a fiber material, the transport mechanism 62 that transports the accumulated fiber material by using the transport belt 62a, and the forming mechanism 70 that forms the transported fiber material into a sheet. The transport mechanism 62 includes the rotary brush 1100 that cleans a surface of the transport belt 62a, the comb 1200 that comes in contact with the rotary brush 1100, and the paddle 1300 that is located on an opposite side of the comb 1200 from the rotary brush 1100 and located at a position where the paddle 1300 does not come in contact with the rotary brush 1100 and the comb 1200. The method includes inserting the front end 1210 of the comb 1200 from below the rotary brush 1100, sweeping and gathering the residual fiber PP, which is attached to the transport belt 62a, to the base 1220 of the comb 1200 via the rotary brush 1100 by rotating the transport belt 62a and the rotary brush 1100 in the first direction, and removing the residual fiber PP gathered at the base 1220 of the comb 1200 by rotating the paddle 1300 in the second direction that is opposite to the first direction to sweep the surface of the comb 1200.

According to this method, since the comb 1200 is inserted into the rotary brush 1100, damage to the rotary brush 1100 can be reduced, for example, compared to a case where a plate-shaped blade is inserted into the rotary brush 1100, and thus deterioration of the cleaning performance of the rotary brush 1100 can be reduced. Furthermore, the paddle 1300 sweeping the surface of the comb 1200 can remove the residual fibers PP accumulated on the surface of the comb 1200 from the comb 1200.

Hereinafter, modifications of the above-described embodiment will be described.

The comb 1200 is not limited to one including the multiple bars 1230 and may include needles arranged in a comb-like shape. The configuration including the arranged needles can have spaces having a large depth from the front end to the bottom and thus can provide a region that does not come in contact with the rotary brush 1100.

The interval W2 between the adjacent bars 1230 of the comb 1200 is not limited to 0.7 mm described above. The interval W2 may be made smaller when residual fibers PP to be removed are small.

The collection unit 1000 is not limited to one located on the front surface side of the transport belt 62a to remove the attached residual fiber PP but may be used at another position to remove the residual fiber PP. For example, when the residual fiber PP attached to the rear surface of the transport belt 62a needs to be removed, the collection unit 1000 may also be disposed on the rear surface side of the transport belt 62a. In addition, if the residual fiber PP attached to the accumulation belt 61a, which is the transport belt, may cause a problem, the collection unit 1000 can be used to remove the attached residual fiber PP. Furthermore, if the residual fiber PP attached to other belts or rollers may cause a problem, the collection unit 1000 can be used for the belts or rollers to remove the attached residual fiber PP.