Sheet manufacturing device

Abstract

To prevent risk of deforming a sheet that is molded by pressurizing and heating a web.SOLUTION: A sheet manufacturing device 1 has an accumulation part 50 to form a web by accumulating materials including fibers, and a molding part 70 to mold the web W into a sheet P1 by pressurizing and heating the web. The molding part 70 comprises: a first roller 72 to heat the web W and the sheet P1; a second roller 73 to nip the web W between itself and the first roller 72; a winding roller 74 that is disposed on the downstream side of the first roller 72 in a transportation direction in which the sheet P1 is transported and winds the sheet P1 around the first roller 72; and press rollers 761, 762, 763 that press the sheet P1 wound around the first roller 72 against the first roller 72.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a sheet manufacturing apparatus.

Background Art

[0002] Patent Document 1 discloses a sheet manufacturing apparatus that forms a sheet while continuously conveying a web by heating and pressing a web on which fibers are deposited with a pair of heated and pressurized rollers.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the sheet manufacturing apparatus of Patent Document 1, downstream of the heated and pressurized roller in the conveyance direction of the sheet, the formed sheet dries and shrinks, and deformation such as wrinkles is likely to occur in the sheet. In this case, there is a risk of conveyance failure of the sheet downstream of the heated and pressurized roller in the conveyance direction of the sheet.

Means for Solving the Problems

[0005] The sheet manufacturing apparatus includes a deposition unit that forms a web by depositing a material containing fibers, and a forming unit that forms a sheet by pressing and heating the web. The forming unit includes a first roller that heats the web and the sheet, a second roller that nips the web between the first roller, a winding roller that is provided downstream of the first roller in the conveyance direction in which the sheet is conveyed and winds the sheet around the first roller, and a pressing roller that presses the sheet wound around the first roller toward the first roller.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0007] Hereinafter, the present disclosure will be described based on embodiments. In the following embodiments, as the sheet manufacturing apparatus 1 for manufacturing sheets P1, P2, and P3 from a material containing fibers, a sheet manufacturing apparatus 1 that dry-recycles paper pieces such as waste paper will be exemplified and described with reference to the drawings. The sheet manufacturing apparatus 1 of the present invention is not limited to being dry, and may be wet. In the present embodiment, "dry" means that the process of mainly fiberizing waste paper is carried out in air such as the atmosphere, not in a liquid.

[0008] In each figure, the same members are denoted by the same reference numerals, and redundant descriptions are omitted. In this specification, "the same", "identical", and "simultaneous" do not only refer to being completely the same. For example, in this specification, "the same", "identical", and "simultaneous" include cases where they are the same considering measurement errors. Also, for example, in this specification, "the same", "identical", and "simultaneous" include cases where they are the same considering manufacturing variations of members.

[0009] Also, for example, in this specification, "the same", "identical", and "simultaneous" include cases where they are the same within a range that does not impair the function. Therefore, for example, "the dimensions of both are the same" means that considering measurement errors and manufacturing variations of members, the dimensional difference between the two is within ±5 percent, particularly preferably within ±3 percent of one of the dimensions.

[0010] In each figure, X, Y, and Z represent three mutually perpendicular spatial axes. In this specification, the directions along these axes are referred to as the X-axis direction, the Y-axis direction, and the Z-axis direction. When specifying a direction, the positive direction is denoted as "+", the negative direction as "-", and both positive and negative signs are used in the direction notation. The direction in which the arrow in each figure points is the + direction, and the opposite direction of the arrow is the - direction for explanation.

[0011] The Z-axis direction indicates the direction of gravity, with the +Z direction being vertically upward and the -Z direction being vertically downward. The plane containing the X-axis and Y-axis is the X-Y plane, the plane containing the X-axis and Z-axis is the X-Z plane, and the plane containing the Y-axis and Z-axis is the Y-Z plane. The X-Y plane is the horizontal plane. For the three spatial axes X, Y, and Z without limiting the positive and negative directions, they are described as the X-axis, the Y-axis, and the Z-axis.

[0012] The X-axis direction is the horizontal direction along the installation surface, which is the horizontal plane on which the sheet manufacturing apparatus 1 is installed. The Y-axis direction is the horizontal direction along the installation surface on which the sheet manufacturing apparatus 1 is installed. The Z-axis direction is the normal direction to the installation surface on which the sheet manufacturing apparatus 1 is installed and is the height direction of the sheet manufacturing apparatus 1.

[0013] In the following description, the +Z direction may be referred to as "upward" and the -Z direction as "downward". In the following description, in the sheet manufacturing apparatus 1, the front in the conveyance direction of raw materials, webs, sheets, etc. may also be referred to as "downstream", and the side going against the conveyance direction as "upstream". For the sake of illustration, the sizes of each member are made different from the actual ones.

[0014] 1. Embodiment 1 As shown in FIG. 1, the sheet manufacturing apparatus 1 of this embodiment 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 a frame (not shown).

[0015] 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 side view in the -X direction, from the -Y direction toward the +Y direction. In FIG. 1, the directions in which the waste paper C, the web W, the sheets P1, P2, P3, the slit pieces S, and the unnecessary end materials move are indicated by white arrows.

[0016] The sheet manufacturing apparatus 1 manufactures the sheet P3 from the waste paper C which is a material containing fibers. According to the sheet manufacturing apparatus 1 of the present embodiment, since the sheet P3 can be manufactured from the waste paper C, the amount of waste paper C discarded is reduced by recycling the waste paper C. Therefore, the sheet manufacturing apparatus 1 of the present embodiment can contribute to the achievement of sustainable development goals (SDGs) such as Goal 12 "Ensure sustainable consumption and production patterns".

[0017] The waste paper C is conveyed from the first unit group 101 to the second unit group 102 via the pipe 21 that crosses inside the third unit group 103. The waste paper C is defibered and the like in the second unit group 102 to become fibers, and then becomes a mixture containing a binder material and the like as a binder. The mixture is conveyed to the third unit group 103 via the pipe 24. The mixture is made into the web W in the third unit group 103 and then formed into the belt-like sheet P1. The belt-like sheet P1 is cut in the first unit group 101 to become the sheet P3.

[0018] The first unit group 101 has a buffer tank 13, a metering supply unit 15, a confluence unit 17, and a pipe 21. In the first unit group 101, these components are arranged in the above order from upstream to downstream. The first unit group 101 also has a first cutting unit 81, a second cutting unit 82, a tray 84, and a shredding unit 86.

[0019] The first cutting unit 81 and the second cutting unit 82 cut the belt-like sheet P1 into the sheet P3 having a predetermined shape. The first unit group 101 has a water supply unit 67. The water supply unit 67 is a water storage tank. The water supply unit 67 supplies humidifying water to each of the first humidifying unit 65 and the second humidifying unit 66, which will be described later, through a water supply pipe (not shown).

[0020] The waste paper C is fed from the raw material inlet 11 to the buffer tank 13. The waste paper C contains fibers such as cellulose and is, for example, shredded waste paper pieces. Humidified air is supplied from the second humidifying unit 66 provided in the third unit group 103 into the buffer tank 13.

[0021] The waste paper C to be defibrated is temporarily stored in the buffer tank 13 and then conveyed to the metering supply unit 15 according to the operation of the sheet manufacturing apparatus 1. The sheet manufacturing apparatus 1 may be provided with a shredder for shredding the waste paper C etc. on the upstream side of the buffer tank 13.

[0022] The metering supply unit 15 has a weighing device 15a and a supply mechanism (not shown). The weighing device 15a weighs the mass of the waste paper C. The supply mechanism supplies the waste paper C weighed by the weighing device 15a to the downstream confluence part 17. The metering supply unit 15 weighs the waste paper C by the weighing device 15a for each predetermined mass and supplies it to the downstream confluence part 17 by the supply mechanism.

[0023] Either a digital type or an analog type weighing mechanism can be applied to the weighing device 15a. Specifically, examples of the weighing device 15a include physical sensors such as load cells, spring scales, and balances. In the present embodiment, a load cell is used as the weighing device 15a. The predetermined mass at which the weighing device 15a weighs the waste paper C is, for example, about several grams to several tens of grams.

[0024] A vibratory feeder or the like can be applied to the supply mechanism. The supply mechanism may be a configuration included in the weighing device 15a.

[0025] The weighing and supply of the waste paper C in the metering supply unit 15 are batch processes. The supply of the waste paper C from the metering supply unit 15 to the confluence part 17 is carried out intermittently. The metering supply unit 15 may have a plurality of weighing devices 15a, and the plurality of weighing devices 15a may be operated with a time difference to improve the efficiency of weighing.

[0026] In the confluence section 17, shredded pieces of the slit pieces S supplied from the shredding section 86 are joined and mixed with the waste paper C supplied from the metering supply section 15. The slit pieces S and the shredding section 86 will be described later. The waste paper C mixed with the shredded pieces flows from the confluence section 17 into the pipe 21.

[0027] The pipe 21 conveys the waste paper C from the first unit group 101 to the second unit group 102 by an air flow generated by a blower (not shown).

[0028] The second unit group 102 includes a defibrator 30 which is a dry defibrator, a separator 40, a pipe 23, a mixing section 91, and a pipe 24. In the second unit group 102, these components are arranged in the above order from upstream to downstream. The second unit group 102 also includes a recovery section 95, a compressor 97, a power supply section 99, a pipe 25 connected to the separator 40, and an air flow pipe 451.

[0029] The waste paper C conveyed through the pipe 21 flows into the defibrator 30. The defibrator 30 dry-defibrates the waste paper C supplied from the metering supply section 15 into fibers. A mechanical defibrating mechanism or the like that loosens the waste paper C with mechanical force can be applied to the defibrator 30. By the defibrator 30, the waste paper C becomes a defibrated product containing fibers in which the entangled fibers contained in the paper pieces are unraveled, and is conveyed to the separator 40.

[0030] Since the defibrator 30 of the present embodiment defibrates the waste paper C into fibers in a dry manner, the amount of water used and the amount of wastewater can be reduced as compared with a wet defibrating method in which defibrating is performed in water. Therefore, the defibrator 30 of the present embodiment can contribute to the achievement of sustainable development goals (SDGs) such as Goal 6 "Ensure access to water and sanitation for all and their sustainable management". The defibrator 30 of the present embodiment can contribute to the achievement of sustainable development goals (SDGs) such as Goal 14 "Conserve and sustainably use the oceans, seas and marine resources for sustainable development".

[0031] According to the fiberizer 30 of the present embodiment, it is not necessary to dry the defibered material, so the amount of carbon dioxide generated in the process of defibering waste paper C can be reduced. Therefore, the fiberizer 30 of the present embodiment can contribute to the achievement of sustainable development goals (SDGs) such as Goal 13, "Take urgent action to combat climate change and its impacts."

[0032] The separator 40 separates the defibered fibers. Specifically, the separator 40 removes components contained in the fibers that are unnecessary for the production of the sheet P3. The separator 40 separates relatively long fibers and relatively short fibers. Since relatively short fibers may cause a decrease in the strength of the sheet P3, they are selected and excluded by the separator 40. The separator 40 also excludes coloring materials, additives, etc. contained in the waste paper C. The separator 40 is of a disk type.

[0033] Inside the separator 40, air humidified by the second humidifying part 66 of the third unit group 103 is supplied.

[0034] The defibered fibers are transported to the mixing part 91 through the pipe 23 by the airflow generated by a blower (not shown) disposed at the tip of the airflow pipe 451 after relatively short fibers and the like are excluded. Unnecessary components such as relatively short fibers and coloring materials are discharged from the pipe 25 to the recovery part 95.

[0035] The mixing part 91 mixes a binder and the like with the fibers in the air to form a mixture. Although not shown, the mixing part 91 includes a flow path through which the fibers are transported, a fan, a hopper, a supply pipe, and a valve.

[0036] The hopper communicates with the fiber flow path through the supply pipe. The valve is provided in the supply pipe between the hopper and the flow path. The hopper supplies a binder such as starch into the flow path. The valve adjusts the mass of the binder supplied from the hopper to the flow path. Thereby, the mixing ratio of the fibers and the binder is adjusted.

[0037] In addition to the above-described configuration for supplying the binder, the mixing part 91 may be provided with a similar configuration for supplying a coloring material, an additive, etc.

[0038] The fan of the mixing unit 91 uses the generated air flow to convey the fibers downstream while mixing materials such as the binder in the air to form a mixture. The mixture flows from the mixing unit 91 into the pipe 24.

[0039] The recovery unit 95 is provided with a filter (not shown). The filter filters out unnecessary components such as relatively short fibers conveyed through the pipe 25 by the air flow.

[0040] The compressor 97 generates compressed air. In the above filter, clogging may occur due to fine particles and the like among the unnecessary components. It is possible to spray the compressed air generated by the compressor 97 onto the filter to blow off the attached particles and clean the filter.

[0041] The power supply unit 99 has a power supply device (not shown) that supplies power to the sheet manufacturing apparatus 1. The power supply unit 99 distributes the power supplied from the outside to each component of the sheet manufacturing apparatus 1. The control unit 5 is provided in the power supply unit 99. The control unit 5 is electrically connected to each component of the sheet manufacturing apparatus 1 and integrally controls the operation of these components.

[0042] The control unit 5 may include one or more processors that execute various processes according to a program, one or more dedicated hardware circuits such as application-specific integrated circuits that execute at least some of the various processes, or a combination thereof. The processor includes a CPU and memories such as a RAM and a ROM, and the memories store program codes or instructions configured to cause the CPU to execute processes. The memory, that is, the computer-readable medium, includes any readable medium accessible by a general-purpose or dedicated computer.

[0043] The third unit group 103 deposits and compresses the mixture containing fibers and forms it into a belt-shaped sheet P1 that is recycled paper. The third unit group 103 includes a deposition unit 50, a first conveyance unit 61, a second conveyance unit 62, a first humidifying unit 65, a second humidifying unit 66, a drainage unit 68, and a forming unit 70 that is a sheet forming unit.

[0044] In the third unit group 103, the deposition part 50, the first conveying part 61, the second conveying part 62, the first humidifying part 65, and the forming part 70 are arranged in the above order from upstream to downstream. The second humidifying part 66 is arranged below the first humidifying part 65.

[0045] The deposition part 50 deposits the mixture containing fibers supplied from the separator 40 by airflow and gravity to form the web W. The deposition part 50 includes a drum member 53, a blade member 55 installed inside the drum member 53, a housing 51 that houses the drum member 53, and a suction part 59. The mixture is taken into the inside of the drum member 53 from the pipe 24.

[0046] The first conveying part 61 is arranged below the deposition part 50. The first conveying part 61 includes a first conveying belt 61a and a tensioning roller 31 that tensions the first conveying belt 61a. The suction part 59 faces the drum member 53 across the first conveying belt 61a in the direction along the Z axis.

[0047] The blade member 55 is inside the drum member 53 and is rotationally driven by a motor (not shown). The drum member 53 is a semi-cylindrical sieve. A net having the function of a sieve is provided on the side surface facing downward of the drum member 53. The drum member 53 allows particles such as fibers and mixtures smaller than the mesh size of the sieve net to pass from the inside to the outside.

[0048] The mixture is discharged to the outside of the drum member 53 while being agitated by the rotating blade member 55 inside the drum member 53. Humidified air from the second humidifying part 66 is supplied to the inside of the drum member 53.

[0049] The suction part 59 is disposed below the drum member 53. The suction part 59 sucks the air in the housing 51 through a plurality of holes in the first conveyor belt 61a. Thereby, an air flow for depositing the mixture on the first conveyor belt 61a is generated. The plurality of holes in the first conveyor belt 61a allow air to pass through but make it difficult for fibers, binder, etc. contained in the mixture to pass through. Thereby, the mixture discharged to the outside of the drum member 53 is sucked downward together with the air. The suction part 59 is a suction device such as a blower.

[0050] The mixture is dispersed in the air in the housing 51 and accumulates on the upper surface of the first conveyor belt 61a due to gravity and the air flow generated by the suction part 59 to form the web W.

[0051] The first conveyor belt 61a is an endless belt and is stretched by the stretching roller 31. The first conveyor belt 61a rotates counterclockwise as viewed from the -X direction in FIG. 1 due to the rotation of the stretching roller 31. Thereby, the mixture continuously accumulates on the first conveyor belt 61a and the web W is formed. The web W contains relatively a lot of air and is soft and swollen. The first conveying part 61 conveys the formed web W downstream by the rotation of the first conveyor belt 61a.

[0052] The second conveying part 62 conveys the web W in place of the first conveying part 61 downstream of the first conveying part 61. The second conveying part 62 peels the web W from the upper surface of the first conveyor belt 61a and conveys it toward the forming part 70. The second conveying part 62 is above the conveying path of the web W and is disposed slightly upstream of the starting point on the return side of the first conveyor belt 61a. A part of the +Y direction of the second conveying part 62 and the -Y direction of the first conveyor belt 61a overlap in the vertical direction.

[0053] The second conveying part 62 includes a second conveyor belt 62a, a plurality of rollers 32, and a suction mechanism (not shown). The second conveyor belt 62a is provided with a plurality of holes for passing air. The second conveyor belt 62a is stretched by a plurality of rollers 32 and rotates by the rotation of the rollers 32.

[0054] The second conveying unit 62 adsorbs the upper surface, which is one surface of the web W, to the lower surface of the second conveying belt 62a by the negative pressure generated by the suction mechanism. In this state, as the second conveying belt 62a rotates, the web W is adsorbed to the second conveying belt 62a and conveyed downstream.

[0055] A cleaning unit 201 is provided in a region extending below the first conveying unit 61 and the second conveying unit 62 from the overlapping portion of the first conveying unit 61 and the second conveying unit 62. The cleaning unit 201 is provided with a brush roller or the like for removing residual fibers adhering to the first conveying belt 61a and the second conveying belt 62a.

[0056] A fiber conveying pipe 22 for conveying the residual fibers collected by the cleaning unit 201 to the defibrator 30 is connected to the cleaning unit 201. Specifically, the cleaning unit 201 is connected to the defibrator 30 via the fiber conveying pipe 22, the confluence unit 17, and the pipe 21.

[0057] The confluence unit 17 is connected to the buffer tank 13, the fiber conveying pipe 22, and the defibrator 30. The residual fibers collected by the cleaning unit 201 flow into the defibrator 30 through the fiber conveying pipe 22, the confluence unit 17, and the pipe 21. The fiber conveying pipe 22 is provided with a rotary valve 56 that moves the residual fibers falling from above downward by the rotation of the blades.

[0058] The residual fibers collected by the cleaning unit 201 are conveyed to the defibrator 30 via the fiber conveying pipe 22. Thereby, it is possible to suppress the user from removing the residual fibers adhering to the first conveying belt 61a and the second conveying belt 62a, that is, performing maintenance. Thereby, it is possible to reduce the amount of residual fibers discarded as waste and suppress the waste of raw materials.

[0059] The first humidifying unit 65 humidifies the web W containing fibers deposited in the deposition unit 50 of the third unit group 103. Specifically, the first humidifying unit 65 is, for example, a mist-type humidifier that supplies mist M from below to the web W conveyed by the second conveying unit 62 for humidification. The first humidifying unit 65 is disposed below the second conveying unit 62 and faces the web W conveyed by the second conveying unit 62 in the direction along the Z axis. A humidifying device such as an ultrasonic type can be applied to the first humidifying unit 65.

[0060] The moisture content of the web W to which moisture is imparted in the first humidifying unit 65 is, for example, 12% by mass or more and 40% by mass or less. When the web W is humidified with the mist M, the function as a binder of starch is promoted, and the strength of the sheet P3 is improved.

[0061] Since the first humidifying unit 65 humidifies the web W from below, the fall of droplets derived from the mist onto the web W is prevented. Since the first humidifying unit 65 humidifies from the opposite side of the contact surface between the second conveying belt 62a and the web W, the adhesion of the web W to the second conveying belt 62a is reduced. The second conveying unit 62 conveys the web W toward the forming unit 70.

[0062] The forming unit 70 forms the humidified web W into a belt-shaped sheet P1 by pressurizing and heating it. The forming unit 70 includes a processing roller pair 71 composed of a first roller 72 capable of heating the web W and the sheet P1, and a second roller 73 provided between the first roller 72 and the web W so as to nip the web W.

[0063] The first roller 72 and the second roller 73 rotate while pressurizing and heating the web W in a nipped state, thereby forming the web W into the sheet P1 and sending out the sheet P1 downstream in the conveying direction. The detailed configuration of the forming unit 70 will be described later.

[0064] The web W passes through the forming section 70, changing from a relatively air-rich and soft state to a state where the enclosed air is reduced and the fibers are bound together by a binder such as starch, and is formed into a strip-shaped sheet P1. The strip-shaped sheet P1 is conveyed toward the first unit group 101 by a pair of conveying rollers 79 provided downstream of the pair of processing rollers 71 and the winding roller 74.

[0065] The second humidifying section 66 is disposed below the first humidifying section 65. A vaporizing type humidifying device can be applied to the second humidifying section 66. Examples of the vaporizing type humidifying device include those that generate humidified air by blowing air onto a moistened nonwoven fabric to vaporize moisture.

[0066] The second humidifying section 66 humidifies a predetermined area of the sheet manufacturing apparatus 1. The predetermined area is one or more of the buffer tank 13, the separator 40, and the drum member 53 of the deposition section 50. Specifically, humidified air is supplied from the second humidifying section 66 to the above area through a plurality of pipes (not shown). The humidified air suppresses the charging of waste paper C, fibers, etc. in each of the above configurations, and suppresses the adhesion of these to members due to static electricity.

[0067] The drainage section 68 is a drainage tank. The drainage section 68 is used in the first humidifying section 65, the second humidifying section 66, etc., and collects and stores the old moisture. The drainage section 68 can be removed from the sheet manufacturing apparatus 1 as necessary to discard the accumulated water.

[0068] The strip-shaped sheet P1 conveyed to the first unit group 101 reaches the first cutting section 81. The first cutting section 81 cuts the strip-shaped sheet P1 in a direction intersecting the conveying direction, for example, along the X-axis. The strip-shaped sheet P1 is cut into single-sheet-shaped sheets P2 at the first cutting section 81. The single-sheet-shaped sheets P2 are conveyed from the first cutting section 81 to the second cutting section 82.

[0069] The second cutting unit 82 cuts the single-sheet-like sheet P2 in the conveying direction, for example, the direction along the Y-axis. Specifically, the second cutting unit 82 cuts the vicinity of both sides in the direction along the X-axis of the single-sheet-like sheet P2. As a result, the single-sheet-like sheet P2 becomes a sheet P3 having a predetermined shape such as A4 size or A3 size.

[0070] When the single-sheet-like sheet P2 is cut into the sheet P3 by the second cutting unit 82, a slit piece S which is a scrap is generated. The slit piece S is conveyed in the substantially -Y direction and reaches the shredding unit 86 which is a shredder. The shredding unit 86 shreds the slit piece S into shredded pieces and supplies them to the confluence unit 17. A mechanism for weighing the shredded pieces of the slit piece S and supplying them to the confluence unit 17 may be installed between the shredding unit 86 and the confluence unit 17.

[0071] The sheet P3 is conveyed substantially upward and stacked on the tray 84. Thus, the sheet P3 is manufactured by the sheet manufacturing apparatus 1. The sheet P3 can be applied as a substitute for, for example, copy paper.

[0072] Next, the detailed configuration of the forming unit 70 will be described. In the present embodiment, since starch is used as the binding material to form the sheet P1, it is necessary to apply moisture to the web W containing starch. For this reason, since the moisture content in the web W becomes relatively high, for example, when moisture evaporates from the formed sheet P1, wrinkles and the like are likely to occur, and it becomes difficult to maintain the smoothness of the sheet P1.

[0073] Therefore, in addition to the above-described processing roller pair 71, the forming unit 70 includes a winding roller 74, a pressing mechanism 75 having a pressing roller 762, and a peeling unit 78 (see FIG. 2). The winding roller 74 is provided downstream of the first roller 72 in the conveying direction and winds the sheet P1 around the first roller 72. The pressing roller 762 included in the pressing mechanism 75 is provided so as to be able to press the sheet P1 wound around the first roller 72 toward the first roller 72.

[0074] As shown in FIGS. 2 and 3, the rotation axes of the first roller 72 and the second roller 73 that constitute the processing roller pair 71 are arranged along the direction along the X axis. As shown in FIG. 3, the first roller 72 is arranged on the -Z direction side of the conveyance path along which the web W is conveyed. In FIGS. 2 and 3, of the web W, the contact surface with the second conveyance belt 62a is defined as the second surface Fb, and the surface on the opposite side of the second surface Fb and on the side that is humidified by the first humidifying unit 65 is shown as the first surface Fa. In FIGS. 1 to 3, of the sheet P1, the surface on the same side as the second surface Fb of the web W is shown as the second surface Fb, and the surface on the same side as the first surface Fa of the web W is shown as the first surface Fa.

[0075] The second roller 73 is arranged on the +Z direction side of the conveyance path. The rotation axis of the second roller 73 is located on the +Z direction side and -Y direction side with respect to the rotation axis of the first roller 72. The forming unit 70 includes a second roller displacement mechanism (not shown) that enables the second roller 73 to move between the nip positions shown in FIGS. 2 and 3 and a nip release position (not shown). The nip position is a position where the web W can be nipped between the first roller 72 and the second roller 73. The nip release position is located in a direction away from the first roller 72 with respect to the nip position and is a position where the web W cannot be nipped between the first roller 72 and the second roller 73.

[0076] The first roller 72 is rotationally driven by a drive motor (not shown). The second roller 73 is not driven by a drive motor and is a driven roller that interlocks with the rotation of the first roller 72. For example, when the first roller 72 rotates counterclockwise when viewed from the -X direction in a state where the second roller 73 is in contact with the first roller 72, the second roller 73 rotates clockwise.

[0077] The width dimensions of the first roller 72 and the second roller 73 along the X axis are larger than the width dimensions of the conveyed web W and the formed sheet P1 along the X axis. Thereby, the entire region of the web W along the X axis can be nipped by the first roller 72 and the second roller 73.

[0078] In this embodiment, the surface of the first roller 72 is configured to be harder than the surface of the second roller 73. Specifically, the first roller 72 is made of metal, and the second roller 73 is made of metal and rubber covering its surface.

[0079] More specifically, the first roller 72 includes, for example, a hollow mandrel 72c made of aluminum, iron, stainless steel, etc. A surface layer 72s made of a fluororesin, for example, PTFE (polytetrafluoroethylene), is provided on the surface of the first roller 72. As the fluororesin, PFA (tetrafluoroethylene - perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene - hexafluoropropylene copolymer), ETFE (tetrafluoroethylene - ethylene copolymer), etc. can be adopted.

[0080] Alternatively, a surface layer 72s made of a silicone resin or the like may be provided on the surface of the first roller 72. By providing the surface layer 72s, the non - adhesiveness to the web W and the sheet P1 can be enhanced. By providing the surface layer 72s, wear and damage of the mandrel 72c can be suppressed. The first roller 72 of this embodiment has, for example, an outer diameter of 130 mm.

[0081] The second roller 73 includes, for example, a hollow mandrel 73c made of aluminum, iron, stainless steel, etc. The surface of the mandrel 73c is covered by an elastic layer 73e made of silicone rubber or urethane rubber as rubber.

[0082] The hardness of the elastic layer 73e is preferably A10 or more and A35 or less in rubber hardness A, and more preferably A20 or more and A30 or less in rubber hardness A. The rubber hardness is the hardness of type A durometer defined in JIS (Japanese Industrial Standards) K6253 - 3:2012 (Vulcanized rubber and thermoplastic rubber - Method for determining hardness - Part 3: Durometer hardness).

[0083] The thickness of the elastic layer 73e is preferably 1 mm or more and 10 mm or less, more preferably 1 mm or more and 5 mm or less. The surface of the elastic layer 73e is covered by a surface layer 73s composed of a fluororesin layer or a tube containing a fluororesin.

[0084] As the fluororesin, PTFE (polytetrafluoroethylene) and PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) can be adopted. As other fluororesins, FEP (tetrafluoroethylene-hexafluoropropylene copolymer), ETFE (tetrafluorothylene-ethylene copolymer), etc. can be adopted. By providing the surface layer 73s, the non-adhesiveness to the web W and the sheet P1 can be enhanced. By providing the surface layer 73s, the wear and damage of the elastic layer 73e can be suppressed.

[0085] By pressing the web W with the first roller 72 and the second roller 73, the web W is compressed in the thickness direction and thinned, and the fiber density in the web W is increased. The pressure acting on the web W by the nip formed by the first roller 72 and the second roller 73 is preferably 0.1 Mpa or more and 15 MPa or less, more preferably 0.2 Mpa or more and 10 MPa or less. The pressure acting on the web W by the nip formed by the first roller 72 and the second roller 73 is even more preferably 0.4 Mpa or more and 8 MPa or less.

[0086] Within such a pressure range, the deterioration of the fibers can be suppressed, and the sheet P1 with good strength can be manufactured again using the defibrated product obtained by defibrating the manufactured sheets P1 and P3 as raw materials. The second roller 73 of the present embodiment is composed of, for example, a mandrel 73c with a diameter of 96 mm, an elastic layer 73e with a thickness of 2 mm, and a surface layer 73s. Therefore, the second roller 73 of the present embodiment has an outer diameter of 100 mm.

[0087] When pressurizing by nipping the web W, the pressing load of the second roller 73 on the first roller 72 is set within the range of 1000 N to 4000 N, for example, 2500 N.

[0088] As shown in FIGS. 2 and 3, the first roller 72 and the second roller 73 each incorporate a heater 72h, 73h for heating as a heating mechanism. As the heaters 72h, 73h, for example, halogen heaters can be adopted. The surface temperatures of the first roller 72 and the second roller 73 are detected by temperature detection units 72t, 73t. The temperature detection units 72t, 73t may be non-contact temperature sensors, or may be contact-type temperature sensors having a contact portion that contacts the surface of the temperature detection target.

[0089] Based on the respective surface temperatures of the first roller 72 and the second roller 73 acquired by the temperature detection units 72t, 73t, the driving of the respective heaters 72h, 73h is controlled. Thereby, it becomes possible to maintain the respective surface temperatures of the first roller 72 and the second roller 73 at a predetermined temperature. For example, the surface temperature of the first roller 72 is preferably 100°C or more and 130°C or less, and the surface temperature of the second roller 73 is preferably 80°C or more and 100°C or less.

[0090] Since pressurization and heating are simultaneously performed on the web W in the forming unit 70, the configuration of the sheet manufacturing apparatus 1 can be simplified.

[0091] The moisture contained in the web W evaporates after the temperature rises, and the thickness of the web W decreases and the fiber density increases. In addition to the moisture and starch increasing in temperature due to heat and the fiber density increasing due to pressure, the starch gelatinizes, and then the moisture evaporates, so that the plurality of fibers can be bonded to each other through the gelatinized starch.

[0092] The first roller 72 and the second roller 73 constituting the processing roller pair 71 of the present embodiment have different hardnesses. As shown in FIG. 3, when the web W is nipped between the first roller 72 and the second roller 73, the surface of the second roller 73 at the nip position is stably recessed by the pressing force of the first roller 72.

[0093] As a result, a constant nip length Ln is maintained, and the pressure within the nip portion An is stabilized. Since the web W can be pressurized and heated in this state, the fibers within the web W can be surely brought into a state where they can be bonded, and a smooth sheet P1 can be formed.

[0094] The nip portion An refers to a pressurized portion where the web W is pressurized by the first roller 72 and the second roller 73, and the nip length Ln is the dimension in the conveyance direction of the web W within the nip portion An. The nip length Ln is the length dimension from the nip start position to the nip end position of the web W by the first roller 72 and the second roller 73. For example, the nip length Ln in the present embodiment is in the range of 6 mm to 16 mm and is set to, for example, 10 mm. The nip length Ln is formed as a dimension that is substantially constant along the X-axis of the nip portion An.

[0095] Since the web W within the nip portion An is nipped by the first roller 72 and the second roller 73, the moisture applied to the web W is difficult to be discharged to the outside. Therefore, the downstream side in the conveyance direction of the nip portion An is in a state where the moisture of the sheet P1 is high and soft, and the sheet P1 is likely to be deformed by the stress during conveyance, and there is a possibility that wrinkles or the like may occur.

[0096] For this reason, in the present embodiment, a winding portion Aw for evaporating moisture from the formed sheet P1 is provided on the surface of the first roller 72 following the downstream of the nip portion An. The winding portion Aw is a portion of the surface of the first roller 72 that is downstream of the nip end position of the nip portion An and where the first surface Fa of the sheet P1 wound around the first roller 72 comes into contact.

[0097] The downstream end of the winding portion Aw in the conveyance direction is located on the +Z direction side above the lowermost end on the surface of the first roller 72. For this reason, when the sheet P1 is heated by the first roller 72 in the winding portion Aw, the air near the surface on the -Y direction side from the lowermost end of the first roller 72 is also heated by the first roller 72.

[0098] On the +Z direction side above the vertical of the winding portion Aw, the surface of the second roller 73 is located. Therefore, when the sheet P1 is heated by the first roller 72 in the winding portion Aw, the air near the surface on the +Y direction side from the lowermost end of the second roller 73 is also heated by the second roller 73.

[0099] It can be expected that the vicinity of the upstream end in the conveyance direction of the sheet P1 wound around the winding portion Aw is heated from the second surface Fb side by this heated air.

[0100] To form the winding portion Aw on the surface of the first roller 72, a winding roller 74 is provided in the forming unit 70. The winding roller 74 is provided downstream of the processing roller pair 71 in the conveyance direction. The winding roller 74 winds the sheet P1 formed by the processing roller pair 71 around the first roller 72.

[0101] The rotation axis of the winding roller 74 is arranged along the direction along the X axis. The width dimension of the winding roller 74 along the X axis is longer than the width dimension of the conveyed sheet P1 along the X axis. The outer diameter of the winding roller 74 in the present embodiment is set in the range of 6 mm to 40 mm, for example, 20 mm.

[0102] A conveyance roller pair 79 (see FIG. 1) is provided downstream of the winding roller 74. In the conveyance of the sheet P1, the driving of the conveyance roller pair 79 and the processing roller pair 71 is controlled by the control unit 5 so that tension is applied to the sheet P1.

[0103] As a result, by the conveyance by the conveyance roller pair 79 and the processing roller pair 71, a winding portion Aw around which the sheet P1 formed in the nip portion An is wound is formed on the first roller 72. Thereby, the pressurization and heating of the web W in the nip portion An and the heating of the sheet P1 in the winding portion Aw can be executed in parallel.

[0104] By heating the first surface Fa side of the sheet P1 in the winding portion Aw by the first roller 72, the drying of the sheet P1 is promoted, and the moisture contained in the sheet P1 evaporates. By the evaporation of the moisture contained in the sheet P1, deformation and wrinkles due to stress during conveyance can be suppressed. Further, in the winding portion Aw, the sheet P1 is in a state where the binding between the fibers via the gelatinized starch is sufficiently performed.

[0105] The winding length Lw, which is the length dimension in the conveyance direction of the winding portion Aw, is set so that the moisture content contained in the sheet P1 wound around the winding portion Aw reaches below the equilibrium moisture content by the heating by the first roller 72. Thereby, deformation and conveyance failure downstream in the conveyance direction of the sheet P1 formed by the forming portion 70 are suppressed. For example, the winding length Lw in the present embodiment is set in the range of 50 mm to 100 mm, for example, 75 mm. Note that the equilibrium moisture content is the moisture content when the moisture content contained in a member such as the sheet P1 reaches an equilibrium state with the atmosphere in air of a certain temperature and humidity.

[0106] On the other hand, in the process of the moisture content of the sheet P1 wound around the winding portion Aw reaching the equilibrium moisture content, deformation such as wrinkles due to shrinkage during moisture evaporation may occur in the sheet P1. Therefore, the forming portion 70 of the present embodiment is provided with a pressing mechanism 75 including a pressing roller 762. The pressing roller 762 is disposed at a position facing the winding portion Aw in the conveyance path.

[0107] By the heating of the sheet P1 by the first roller 72, moisture evaporates from the second surface Fb of the sheet P1 in the winding portion Aw. If the gaps between the second roller 73 and the pressing roller 762 and between the pressing roller 762 and the winding roller 74 are small, the evaporation of moisture from the sheet P1 in the winding portion Aw is difficult to proceed.

[0108] The outer diameter of the pressing roller 762 is set so as to ensure the above-described gap. As a result, the outer diameter of the pressing roller 762 is set smaller than the outer diameter of the second roller 73 for ensuring the nip length Ln. In the present embodiment, the pressing mechanism 75 includes pressing rollers 761 and 763 in addition to the pressing roller 762. The pressing mechanism 75 in the present embodiment includes a plurality of pressing rollers 761, 762, and 763.

[0109] In this case, if the above-described gap, the gap between the pressing rollers 761, 762, and 763 is small, it is difficult for moisture to evaporate from the sheet P1 in the winding portion Aw. The outer diameters of the pressing rollers 761, 762, and 763 are set so as to ensure the above-described gap, the gap between the pressing rollers 761, 762, and 763. As a result, the outer diameters of the pressing rollers 761, 762, and 763 are set smaller than the outer diameter of the second roller 73. The outer diameters of the pressing rollers 761, 762, and 763 in the present embodiment are the same.

[0110] The plurality of pressing rollers 761, 762, and 763 are arranged at intervals in the conveyance direction in this order from upstream. The pressing rollers 761, 762, and 763 are arranged between the processing roller pair 71 and the winding roller 74 in the conveyance path. The pressing rollers 761, 762, and 763 are arranged at positions facing the winding portion Aw in the conveyance path.

[0111] The pressing mechanism 75 includes a pressing roller moving mechanism 77 that can move the pressing rollers 761, 762, and 763 to a pressing position B1 and a separated position B2. The pressing position B1 is a position where the pressing rollers 761, 762, and 763 press the sheet P1 wound around the first roller 72 toward the winding portion Aw of the first roller 72. Thereby, a nip portion Au is formed between each of the pressing rollers 761, 762, and 763 and the first roller 72.

[0112] The movement of the pressing rollers 761, 762, and 763 is performed by drive control of the pressing roller moving mechanism 77 by the control unit 5.

[0113] Each nip portion Au refers to a pressurized portion that is pressurized against the sheet P1 by the respective pressing rollers 761, 762, 763 and the first roller 72. Each nip length Lu (not shown) is the dimension in the conveyance direction of the sheet P1 in the nip portion Au. Each nip length Lu is the length dimension from the nip start position to the nip end position of the sheet P1 by the respective pressing rollers 761, 762, 763 and the first roller 72. The nip length Lu is formed with a substantially constant length dimension along the X-axis of the nip portion Au.

[0114] The nip portion Au of the pressing roller 762 is located on the downstream side with respect to the center of the winding portion Aw in the conveyance direction. The nip portion Au of the pressing roller 761 is located on the upstream side with respect to the center of the winding portion Aw in the conveyance direction. The nip portion Au of the pressing roller 763 is located on the downstream side with respect to the center between the downstream end of the winding portion Aw and the nip portion Au of the pressing roller 762 in the conveyance direction.

[0115] The separation position B2 is a position where the pressing rollers 761, 762, 763 are separated from the sheet P1 and do not contact the sheet P1.

[0116] The respective rotation axes of the pressing rollers 761, 762, 763 are arranged along the direction along the X-axis. The pressing rollers 761, 762, 763 are arranged on the -Y direction side of the conveyance path along which the sheet P1 is conveyed. For this reason, the separation position B2 is provided at a position separated from the pressing position B1 in the -Y direction. For this reason, the pressing roller moving mechanism 77 of the pressing mechanism 75 is arranged on the -Y direction side of the separation position B2.

[0117] The pressing rollers 761, 762, 763 are driven rollers that are not driven by a drive motor but interlock with the rotation of the first roller 72. When the first roller 72 rotates counterclockwise as viewed from the -X direction, the pressing rollers 761, 762, 763 rotate clockwise.

[0118] The width dimension along the X-axis of the pressing rollers 761, 762, and 763 is larger than the width dimension along the X-axis of the sheet P1 wound around the first roller 72. Thereby, each of the pressing rollers 761, 762, and 763 can press the entire area along the X-axis of the sheet P1 toward the winding portion Aw of the first roller 72. The width dimension along the X-axis of the pressing rollers 761, 762, and 763 in the present embodiment is the same as the width dimension along the X-axis of the first roller 72.

[0119] The pressing rollers 761, 762, and 763 include a shaft 76c made of a metal such as aluminum, iron, or stainless steel. The surface of the shaft 76c is covered with an elastic layer 76e made of a rubber such as silicone rubber or urethane rubber.

[0120] If the rubber hardness of the elastic layer 76e is low, the proportion of the nip portion Au in the winding portion Aw increases. When the proportion of the nip portion Au in the winding portion Aw increases, it becomes difficult for moisture to evaporate from the sheet P1 in the winding portion Aw.

[0121] Therefore, the rubber hardness of the elastic layer 76e is set so that the moisture content contained in the sheet P1 wound around the winding portion Aw reaches below the equilibrium moisture content by heating with the first roller 72.

[0122] As a result, the rubber hardness of the elastic layer 76e of the pressing rollers 761, 762, and 763 is set higher than the rubber hardness of the elastic layer 73e of the second roller 73, which is set soft to ensure the nip length Ln. The rubber hardness of the elastic layer 76e of the pressing rollers 761, 762, and 763 in the present embodiment is the same. The hardness of the elastic layer 76e is preferably A40 or more and A70 or less in rubber hardness, and more preferably A50 or more and A60 or less.

[0123] The thickness of the elastic layer 76e is preferably 1 mm or more and 4 mm or less, and more preferably 1 mm or more and 2 mm or less. The surface of the elastic layer 76e is covered with a surface layer 76s composed of a fluororesin layer or a tube containing a fluororesin.

[0124] As the fluororesin, PFA (tetrafluoroethylene·perfluoroalkyl vinyl ether copolymer) and PTFE (polytetrafluoroethylene) can be adopted. As other fluororesins, FEP (tetrafluoroethylene·hexafluoropropylene copolymer), ETFE (tetrafluorothylene·ethylene copolymer), etc. can be adopted. By providing the surface layer 76s, the non-stick property with respect to the web W and the sheet P1 can be enhanced. By providing the surface layer 76s, the wear and damage of the shaft 76c can be suppressed.

[0125] The sheet P1 is formed by pressing and heating the web W at the nip portion An. Therefore, the pressing load of the pressing rollers 761, 762, 763 that press the sheet P against the first roller 72 may be smaller than the pressing load of the second roller 73 that presses the web W against the first roller 72. The pressing load of each of the pressing rollers 761, 762, 763 in the present embodiment is set in the range of 20 N to 80 N, for example, 60 N.

[0126] As a result, the pressure acting on the sheet P1 by the pressing rollers 761, 762, 763 pressing the sheet P1 against the first roller 72 is smaller than the pressure acting on the web W by the processing roller pair 71 nipping the web W.

[0127] The pressing rollers 761, 762, 763 of this embodiment are composed of, for example, a shaft 76c with a diameter of 10 mm, an elastic layer 76e with a thickness of 2 mm, and a surface layer 76s made of a PFA tube with a thickness of 50 μm. Therefore, the pressing rollers 761, 762, 763 of this embodiment have an outer diameter of 14 mm. The nip length Lu in the nip portion Au formed by each of the pressing rollers 761, 762, 763 and the first roller 72 is from 0.5 mm to 3 mm. From the viewpoint of preventing wrinkles from occurring, it is preferable that the outer diameters of the pressing rollers 761, 762, 763 are the same across the width direction, but a portion with a smaller outer diameter may be provided in the pressing rollers 761, 762, 763. In this case, as the pressing rollers 761, 762, 763, forms such as a stepped roller or a split roller can also be used.

[0128] The peeling portion 78 is provided between the winding portion Aw of the first roller 72 and the winding roller 74 in the conveyance path. The peeling portion 78 includes a thin plate-shaped peeling plate. The width dimension of the peeling plate along the X-axis is larger than the width dimension of the sheet P1 wound around the first roller 72 along the X-axis. When the tip of the peeling plate contacts the surface of the first roller 72, the sheet P1 wound around the winding portion Aw is peeled off from the surface of the first roller 72.

[0129] The peeling portion 78 includes a peeling plate movement mechanism (not shown) that can move between a contact position C1 (see FIG. 3) where the peeling plate contacts the surface of the first roller 72 and a retracted position C2 (see FIG. 2) where the peeling plate separates from the surface of the first roller 72. The movement of the peeling plate is performed by drive control of the peeling plate movement mechanism by the control unit 5.

[0130] The control unit 5 controls the forming unit 70 to form the web W into the sheet P1 by passing it through the nip portion An and the winding portion Aw formed in the conveyance path. When forming the web W into the sheet P1, the driving of the heaters 72h and 73h is controlled by the control unit 5, so that the surface temperatures of the first roller 72 and the second roller 73 are maintained at predetermined temperatures. When forming the web W into the sheet P1, the driving of the second roller displacement mechanism is controlled by the control unit 5, so that the second roller 73 is positioned at the nip position.

[0131] When forming the web W into the sheet P1, the driving of the conveyance roller pair 79 and the first roller 72 is controlled by the control unit 5, so that tension is applied to the sheet P1. At this time, the first roller 72 rotates counterclockwise when viewed from the -X direction. When forming the web W into the sheet P1, the driving of the pressing roller moving mechanism 77 is controlled by the control unit 5, so that the pressing rollers 761, 762, and 763 are positioned at the pressing position B1. When forming the web W into the sheet P1, the driving of the peeling plate moving mechanism is controlled by the control unit 5, so that the peeling plate is positioned at either the contact position C1 or the retracted position C2.

[0132] As described above, according to the sheet manufacturing apparatus 1 according to Embodiment 1, the following effects can be obtained.

[0133] The sheet manufacturing apparatus 1 includes a deposition unit 50 that forms the web W by depositing a material containing fibers, and a forming unit 70 that forms the web W into the sheet P1 by pressurizing and heating it. The forming unit 70 includes a first roller 72 that heats the web W and the sheet P1, and a second roller 73 that nips the web W between the first roller 72. The forming unit 70 is provided downstream of the first roller 72 in the conveyance direction in which the sheet P1 is conveyed, and has a winding roller 74 that winds the sheet P1 around the first roller 72. The forming unit 70 includes pressing rollers 761, 762, and 763 that press the sheet P1 wound around the first roller 72 toward the first roller 72.

[0134] According to this, it is possible to manufacture the sheet P1 dried to a moisture content below the equilibrium moisture content without causing deformation such as wrinkles by the forming unit 70. Thereby, it is possible to suppress the occurrence of conveyance failure of the sheet P1 formed by the forming unit 70.

[0135] The pressing rollers 761, 762, 763 have a width wider than the width of the sheet P1. According to this, the sheet P1 wound around the first roller 72 can be pressed toward the first roller 72 over the width dimension of the sheet P1.

[0136] When pressing the sheet P1 against the first roller 72, the pressing rollers 761, 762, 763 rotate following the rotation of the first roller 72. According to this, the sheet P1 wound around the first roller 72 can be stably pressed toward the first roller 72.

[0137] The outer diameter of the pressing rollers 761, 762, 763 is smaller than the outer diameter of the second roller 73. According to this, the sheet P1 wound around the first roller 72 is likely to be dried by the heating of the sheet P1 by the first roller 72.

[0138] The elastic layer 76e constituting the surface of the pressing rollers 761, 762, 763 has a higher hardness than the elastic layer 73e constituting the surface of the second roller 73. According to this, the sheet P1 wound around the first roller 72 is likely to be dried by the heating of the sheet P1 by the first roller 72.

[0139] The pressure acting on the sheet P1 when the pressing rollers 761, 762, 763 press the sheet P1 toward the first roller 72 is smaller than the pressure acting on the web W when the first roller 72 and the second roller 73 nip the web W. According to this, the sheet P1 wound around the first roller 72 is likely to be dried by the heating of the sheet P1 by the first roller 72.

[0140] The forming unit 70 has a plurality of pressing rollers 761, 762, 763 spaced apart in the conveying direction. According to this, compared with the case where the forming unit 70 includes a single pressing roller 762, the interval between the positions where the sheet P1 is pressed toward the first roller 72 in the conveying direction of the sheet P1 can be made smaller. Thereby, in the conveying direction of the sheet P1, it is possible to further suppress the occurrence of deformation such as wrinkles in the sheet P1 formed by the forming unit 70. Therefore, it is possible to further suppress the occurrence of conveyance failure of the sheet P1 formed by the forming unit 70.

[0141] The sheet manufacturing apparatus 1 according to the above-described Embodiment 1 of the present disclosure is basically configured as described above, but it is of course possible to make partial configuration changes, omissions, etc. within a range not departing from the gist of the present disclosure. Further, the above-described Embodiment 1 and other embodiments described below can be implemented in combination with each other within a range where there is no technical contradiction. Other embodiments will be described below.

[0142] In the above-described Embodiment 1, the nip portion Au of the pressing roller 762 may be located at the center of the winding portion Aw in the conveying direction of the sheet P1. In this case, the winding portion Aw may be evenly divided into four sections in the conveying direction by the nip portions Au of the respective pressing rollers 761, 762, 763.

[0143] In the above-described Embodiment 1, the forming unit 70 does not necessarily include three pressing rollers 761, 762, 763. The forming unit 70 may include any two of the three pressing rollers 761, 762, 763, or may include any one of them. Alternatively, if a gap between the pressing rollers can be ensured, the forming unit 70 may include four or more pressing rollers. When the forming unit 70 includes a single pressing roller 762, the nip portion Au of the pressing roller 762 may be located at the center of the winding portion Aw in the conveying direction of the sheet P1.

[0144] In the above-described Embodiment 1, the forming unit 70 may include a support portion for reducing the deflection generated in the pressing rollers 761, 762, and 763 at the pressing position B1. For example, the support portion may be a rotating roller that contacts a position on the surface of the pressing rollers 761, 762, and 763 that is on the opposite side of the nip portion Au across the rotation axes of the pressing rollers 761, 762, and 763. This rotating roller may contact a position that is the center in the X-axis direction on the surface of the pressing rollers 761, 762, and 763. This rotating roller may be a driven roller that interlocks with the rotation of the pressing rollers 761, 762, and 763 by contacting the surface of the pressing rollers 761, 762, and 763.

[0145] In the above-described Embodiment 1, the outer diameters of the pressing rollers 761, 762, and 763 may not be the same. For example, the outer diameters of the respective pressing rollers 761, 762, and 763 may be different from each other. For example, the outer diameters of two of the pressing rollers 761, 762, and 763 may be the same, and the outer diameter of the other one may be different. In this case, for example, the outer diameters of the pressing rollers 762 and 763 may be the same, and the outer diameter of the pressing roller 761 may be smaller than the outer diameters of the pressing rollers 762 and 763.

[0146] In the above-described Embodiment 1, the rubber hardness of the elastic layers 76e of the pressing rollers 761, 762, and 763 may not be the same. For example, the rubber hardness of the elastic layers 76e of the respective pressing rollers 761, 762, and 763 may be different from each other. For example, the rubber hardness of the elastic layers 76e of two of the pressing rollers 761, 762, and 763 may be the same, and the rubber hardness of the elastic layer 76e of the other one may be different. In this case, for example, the rubber hardness of the elastic layers 76e of the pressing rollers 761 and 762 may be the same, and the rubber hardness of the elastic layer 73e of the pressing roller 763 may be lower than the rubber hardness of the elastic layers 73e of the pressing rollers 761 and 762.

[0147] In the above-described Embodiment 1, the pressing loads of the pressing rollers 761, 762, and 763 that press the sheet P toward the first roller 72 do not have to be the same. Also in this case, the pressing loads of the pressing rollers 761, 762, and 763 that press the sheet P1 toward the first roller 72 are set to be smaller than the pressing load of the second roller 73 that presses the web W toward the first roller 72. For example, the pressing loads of the respective pressing rollers 761, 762, and 763 may be different from each other. For example, the pressing loads of two of the pressing rollers 761, 762, and 763 may be the same and the pressing load of the other one may be different. In this case, for example, the pressing loads of the pressing rollers 761 and 763 may be the same and the pressing load of the pressing roller 762 may be higher than the pressing loads of the pressing rollers 761 and 763.

Explanation of Signs

[0148] 1... Sheet manufacturing apparatus, 5... Control unit, 11... Raw material inlet, 13... Buffer tank, 15... Quantitative supply unit, 15a... Meter, 17... Confluence part, 21, 23, 24, 25... Pipes, 22... Fiber conveyance pipe, 30... Defibrator, 31... Stretching roller, 32... Roller, 40... Separator, 50... Deposition part, 51... Housing, 53... Drum member, 55... Blade member, 59... Suction part, 61... First conveyance part, 61a... First conveyance belt, 62... Second conveyance part, 62a... Second conveyance belt, 65... First humidifying part, 66... Second humidifying part, 67... Water supply part, 68... Drainage part, 70... Forming part, 71... Treatment roller pair, 72... First roller, 72c... Core metal, 72h... Heater, 72s... Surface layer, 72t... Temperature detection part, 73... Second roller, 73c... Core metal, 73e... Elastic layer, 73h... Heater, 73s... Surface layer, 74... Wrapping roller, 75... Pressing mechanism, 76c... Shaft, 76e... Elastic layer, 76s... Surface layer, 77... Pressing roller moving mechanism, 78... Peeling part, 79... Conveyance roller pair, 81... First cutting part, 82... Second cutting part, 84... Tray, 86... Shredding part, 91... Mixing part, 95... Recovery part, 97... Compressor, 99... Power supply part, 101... First unit group, 102... Second unit group, 103... Third unit group, 201... Cleaning part, 451... Airflow pipe, 761, 762, 763... Pressing rollers, B1... Pressing position, B2... Separation position, C1... Contact position, C2... Retraction position, P1, P2, P3... Sheets, An... Nip part, Au... Nip part, Aw... Wrapping part, Fa... First surface, Fb... Second surface, Ln... Nip length, Lu... Nip length, Lw... Wrapping length.

Claims

1. A deposition unit that forms a web by depositing a material containing fibers, A forming unit that forms the web into a sheet by pressing and heating the web, comprising: The forming unit includes: A first roller that heats the web and the sheet, A second roller that nips the web between the second roller and the first roller, A wrapping roller provided downstream of the first roller in the conveyance direction in which the sheet is conveyed, and that wraps the sheet around the first roller, A pressing roller that presses the sheet wrapped around the first roller against the first roller, having: A sheet manufacturing apparatus characterized by the above.

2. The pressing roller has a width wider than the width of the sheet, The sheet manufacturing apparatus according to claim 1, characterized by the above.

3. When pressing the sheet against the first roller, the pressing roller rotates following the rotation of the first roller, The sheet manufacturing apparatus according to claim 1, characterized by the above.

4. The outer diameter of the pressing roller is smaller than the outer diameter of the second roller, The sheet manufacturing apparatus according to claim 1, characterized by the above.

5. The elastic layer constituting the surface of the pressing roller has a higher hardness than the elastic layer constituting the surface of the second roller, The sheet manufacturing apparatus according to claim 1, characterized by the above.

6. The pressure acting on the sheet when the pressing roller presses the sheet against the first roller is smaller than the pressure acting on the web when the first roller and the second roller nip the web, The sheet manufacturing apparatus according to claim 1, characterized by the above.

7. The forming unit has a plurality of the pressing rollers spaced apart in the conveyance direction, The sheet manufacturing apparatus according to claim 1, characterized by the above.

Images