Sheet manufacturing device and sheet manufacturing method

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 W, a molding part 70 to mold the web W into a sheet P1, and a control part 5. 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 and winds the sheet P1 around the first roller 72; press rollers 761, 762, 763 that press the sheet P1 wound around the first roller 72 against the first roller 72; and a press roller moving part 77 to change positions of the press rollers 761, 762, 763. The control part 5 controls the press roller moving part 77 based on a position of a tip of the sheet P1.SELECTED DRAWING: Figure 11

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a sheet manufacturing apparatus that forms a sheet while continuously conveying a web by heating and pressing the web on which fibers are deposited with a pair of heating and pressing 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 heating and pressing roller in the sheet conveyance direction, 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 heating and pressing roller in the sheet conveyance direction.

Means for Solving the Problems

[0005] The sheet manufacturing apparatus includes a deposition unit that forms a web by depositing a material containing fibers, a forming unit that forms the web into a sheet by pressurizing and heating the web, and a control unit. 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, a pressing roller that presses the sheet wound around the first roller toward the first roller, and a pressing roller moving unit that changes the position of the pressing roller. The control unit controls the pressing roller moving unit based on the position of the leading end, which is the downstream end of the sheet in the conveyance direction.

[0006] A sheet manufacturing method is a sheet manufacturing method in which a web formed by depositing a material containing fibers is formed into a sheet by pressurizing and heating. The method includes rotating the first roller while nipping the web between the heated first roller and the second roller to form the web into the sheet, and conveying the sheet wound around the first roller downstream in the conveyance direction in which the sheet is conveyed while pressing the sheet wound around the first roller against the first roller by a pressing roller at a pressing position. The position of the pressing roller is changed based on the temperature of the first roller, the rotation state of the first roller, and the position of the leading end, which is the downstream end of the sheet.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0008] Hereinafter, the present disclosure will be described based on embodiments. In the following embodiments, as a sheet manufacturing apparatus 1 for manufacturing sheets P1, P2, 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, without being carried out in a liquid.

[0009] In each figure, the same members are denoted by the same reference numerals, and redundant descriptions are omitted. In this specification, "same", "identical", and "simultaneous" do not only refer to being completely the same. For example, in this specification, "same", "identical", and "simultaneous" are intended to include cases where they are the same considering measurement errors. Also, for example, in this specification, "same", "identical", and "simultaneous" are intended to include cases where they are the same considering manufacturing variations of members.

[0010] Also, for example, in this specification, "same", "identical", and "simultaneous" are intended to include cases where they are the same within a range that does not impair the function. Thus, 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.

[0011] In each figure, X, Y, and Z represent three mutually orthogonal 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 is denoted as "-", and both positive and negative signs are used in the direction notation. The direction in which the arrow in each figure points is described as the + direction, and the opposite direction of the arrow is described as the - direction.

[0012] The Z-axis direction indicates the direction of gravity, the +Z direction indicates vertically upward, and the -Z direction indicates vertically downward. The plane including the X-axis and Y-axis is described as the X-Y plane, the plane including the X-axis and Z-axis is described as the X-Z plane, and the plane including the Y-axis and Z-axis is described as the Y-Z plane. The X-Y plane is a 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.

[0013] The X-axis direction is a horizontal direction along the installation surface, which is a horizontal plane on which the sheet manufacturing apparatus 1 is installed. The Y-axis direction is a 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.

[0014] In the following description, the +Z direction may be referred to as "upward" and the -Z direction may be referred to as "downward". In the following description, in the sheet manufacturing apparatus 1, the front in the conveyance direction of the raw material, the web W, the sheet P1, etc. may be referred to as "downstream", and the side going against the conveyance direction may be referred to as "upstream". In the following description, the downstream end in the conveyance direction of the web W, the sheet P1, etc. may be referred to as the "tip". For the sake of illustration, the sizes of the respective members are made different from the actual ones.

[0015] 1. Embodiment 1 As shown in FIG. 1, the sheet manufacturing apparatus 1 of the present 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).

[0016] In the sheet manufacturing apparatus 1, when viewed from the side in the -X direction, the first unit group 101, the third unit group 103, and the second unit group 102 are arranged 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.

[0017] 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".

[0018] The waste paper C is conveyed from the first unit group 101 to the second unit group 102 through a pipe 21 that crosses the third unit group 103. The waste paper C is defibered in the second unit group 102 to form fibers, and then becomes a mixture containing a binder material such as a sizing agent. The mixture is conveyed to the third unit group 103 through a pipe 24. The mixture is formed into a web W in the third unit group 103 and then formed into a strip-shaped sheet P1. The strip-shaped sheet P1 is cut in the first unit group 101 to form a sheet P3.

[0019] The first unit group 101 includes 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 includes a first cutting unit 81, a second cutting unit 82, a tray 84, and a shredding unit 86.

[0020] The first cutting unit 81 and the second cutting unit 82 cut the strip-shaped sheet P1 into a sheet P3 with a predetermined shape. 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 humidifying water to each of a first humidifying unit 65 and a second humidifying unit 66, which will be described later, through a water supply pipe (not shown).

[0021] The waste paper C is fed from a raw material inlet 11 into 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 a second humidifying unit 66 provided in the third unit group 103 into the interior of the buffer tank 13.

[0022] The waste paper C to be defibered 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 and the like on the upstream side of the buffer tank 13.

[0023] The metering and supply unit 15 includes 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 section 17. The metering and supply unit 15 weighs the waste paper C by the weighing device 15a for each predetermined mass and supplies it to the downstream confluence section 17 by the supply mechanism.

[0024] Either a digital or an analog 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 this 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.

[0025] 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.

[0026] The weighing and supply of the waste paper C by the metering and supply unit 15 are batch processes. The supply of the waste paper C from the metering and supply unit 15 to the confluence section 17 is intermittently performed. The metering and 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.

[0027] At the confluence section 17, shredded pieces of the slit pieces S supplied from the shredding section 86 are confluent and mixed with the waste paper C supplied from the metering and supply unit 15. The slit piece 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.

[0028] The pipe 21 conveys the waste paper C from the first unit group 101 to the second unit group 102 by the air flow generated by a blower (not shown).

[0029] The second unit group 102 includes a defiberizer 30 which is a dry defiberizer, 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.

[0030] The waste paper C conveyed through the pipe 21 flows into the defiberizer 30. The defiberizer 30 dry-defibers the waste paper C supplied from the metering supply section 15 into fibers. A mechanical defibering mechanism or the like that loosens the waste paper C with mechanical force can be applied to the defiberizer 30. By the defiberizer 30, the entangled fibers contained in the waste paper pieces are unraveled, and the waste paper C becomes a defibered material containing fibers and is conveyed to the separator 40.

[0031] Since the defiberizer 30 of the present embodiment dry-defibers the waste paper C into fibers, the amount of water used and the amount of wastewater can be reduced as compared with a wet defibering method that performs defibering in water. Therefore, the defiberizer 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 defiberizer 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".

[0032] According to the defiberizer 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 the waste paper C can be reduced. Therefore, the defiberizer 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".

[0033] Separator 40 separates the defibrated fibers. Specifically, separator 40 removes components contained in the fibers that are unnecessary for the production of sheet P3. Separator 40 separates relatively long fibers from relatively short fibers. Since relatively short fibers may cause a decrease in the strength of sheet P3, they are selected and excluded by separator 40. Separator 40 also excludes colorants, additives, etc. contained in waste paper C. Separator 40 is of a disk type.

[0034] Inside separator 40, air humidified by the second humidifying section 66 of the third unit group 103 is supplied.

[0035] The defibrated fibers, from which relatively short fibers and the like have been excluded, are conveyed through pipe 23 to mixing section 91 by the airflow generated by a blower (not shown) disposed at the tip of airflow pipe 451. Unwanted components such as relatively short fibers and colorants are discharged from pipe 25 to recovery section 95.

[0036] Mixing section 91 mixes a binder and the like with the fibers in the air to form a mixture. Although not shown, mixing section 91 includes a flow path through which the fibers are conveyed, a fan, a hopper, a supply pipe, and a valve.

[0037] The hopper communicates with the fiber flow path through a 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.

[0038] In addition to the above-described configuration for supplying the binder, mixing section 91 may be provided with a similar configuration for supplying colorants, additives, etc.

[0039] The fan of mixing section 91 mixes a binder and the like into the air while conveying the fibers downstream by the generated airflow to form a mixture. The mixture flows from mixing section 91 into pipe 24.

[0040] 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.

[0041] 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 blow the compressed air generated by the compressor 97 onto the filter to blow off the attached particles and clean the filter.

[0042] 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. A 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.

[0043] 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 a part 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.

[0044] The third unit group 103 deposits and compresses a mixture containing fibers and forms it into a belt-like 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 which is a sheet forming unit.

[0045] In the third unit group 103, the deposition section 50, the first conveyance section 61, the second conveyance section 62, the first humidification section 65, and the forming section 70 are arranged in the above order from upstream to downstream. The second humidification section 66 is arranged below the first humidification section 65.

[0046] The deposition section 50 deposits a mixture containing fibers supplied from the separator 40 by airflow and gravity to form the web W. The deposition section 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 section 59. The mixture is taken into the inside of the drum member 53 from the pipe 24.

[0047] Below the deposition section 50, the first conveyance section 61 is arranged. The first conveyance section 61 includes a first conveyance belt 61a and a tension roller 31 that stretches the first conveyance belt 61a. The suction section 59 faces the drum member 53 across the first conveyance belt 61a in the direction along the Z axis.

[0048] 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 of the drum member 53 facing downward. 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.

[0049] 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 humidification section 66 is supplied to the inside of the drum member 53.

[0050] The suction part 59 is arranged below the drum member 53. The suction part 59 sucks the air in the housing 51 through a plurality of holes provided in the first conveyor belt 61a. Thereby, an air current 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 it is 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.

[0051] The mixture is dispersed in the air in the housing 51 and is deposited on the upper surface of the first conveyor belt 61a by gravity and the air current generated by the suction part 59 to form the web W.

[0052] The first conveyor belt 61a is an endless belt and is stretched by the stretching roller 31. The first conveyor belt 61a rotates counterclockwise when viewed from the -X direction in FIG. 1 due to the rotation of the stretching roller 31. Thereby, the mixture continuously deposits on the first conveyor belt 61a, and the web W is formed. The web W contains a relatively large amount 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.

[0053] The second conveying part 62 conveys the web W downstream of the first conveying part 61, replacing 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 arranged 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.

[0054] 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.

[0055] The second conveying unit 62 adsorbs the upper surface, which is one side 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.

[0056] 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.

[0057] 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 part 17, and the pipe 21.

[0058] The confluence part 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 part 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.

[0059] 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. As a result, it is possible to reduce the amount of residual fibers to be discarded as waste, and it is possible to suppress the waste of raw materials.

[0060] The first humidifying unit 65 humidifies the web W containing fibers deposited at 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.

[0061] 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 for starch is promoted, and the strength of the sheet P3 is improved.

[0062] 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.

[0063] The forming unit 70 forms the humidified web W into a belt-like 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 first roller 72 so as to nip the web W.

[0064] 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.

[0065] 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 bonded 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.

[0066] 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.

[0067] 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-mentioned 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.

[0068] 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 needed to discard the accumulated water.

[0069] The strip-shaped sheet P1 conveyed to the first unit group 101 reaches the first cutting section 81 after passing through the sheet detection sensor 87. The sheet detection sensor 87 is used to determine whether the sheet P1 has reached the pair of conveying rollers 79. 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.

[0070] 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 in 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.

[0071] 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.

[0072] 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.

[0073] Next, the detailed configuration of the forming unit 70 will be described. In the present embodiment, since starch is used as the binder to form the sheet P1, it is necessary to impart moisture to the web W containing starch. For this reason, since the amount of moisture in the web W becomes relatively large, 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.

[0074] Therefore, in addition to the above-described treatment 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.

[0075] 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.

[0076] 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 the -Y direction side with respect to the rotation axis of the first roller 72. The forming unit 70 includes a second roller displacement unit (not shown) that is capable of moving the second roller 73 to the nip position 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.

[0077] 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 as viewed from the -X direction while the second roller 73 is in contact with the first roller 72, the second roller 73 rotates clockwise.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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, the 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.

[0082] 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.

[0083] 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).

[0084] The thickness of the elastic layer 73e is preferably 1 mm or more and 10 mm or less, and 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.

[0085] 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, wear and damage of the elastic layer 73e can be suppressed.

[0086] 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, and 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.

[0087] Within such a pressure range, fiber degradation can be suppressed, and a 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.

[0088] 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.

[0089] 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 employed. 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 contact-type temperature sensors having a contact portion that contacts the surface of the temperature detection target.

[0090] Based on the surface temperatures of the first roller 72 and the second roller 73 acquired by the temperature detection units 72t, 73t, the driving of the heaters 72h, 73h is controlled. Thereby, it becomes possible to maintain the surface temperatures of the first roller 72 and the second roller 73 at a set temperature. For example, the set temperature of the surface of the first roller 72 is preferably 100°C or higher and 130°C or lower, and the set temperature of the surface of the second roller 73 is preferably 80°C or higher and 100°C or lower.

[0091] In the forming unit 70, since pressurization and heating are simultaneously performed on the web W by the processing roller pair 71, the productivity of the sheet P1 can be improved. 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.

[0092] After the moisture contained in the web W evaporates as the temperature rises, the thickness of the web W decreases and the fiber density increases. In addition to the temperature rise of moisture and starch due to heat and the increase in fiber density due to pressure, the starch gelatinizes, and then the moisture evaporates, so that a state in which a plurality of fibers can be bonded to each other via the gelatinized starch is achieved.

[0093] 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.

[0094] As a result, a constant nip length Ln is maintained, and the pressure within the nip portion An becomes stable. 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.

[0095] 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 to have a substantially constant dimension along the X-axis of the nip portion An.

[0096] 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.

[0097] 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 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.

[0098] 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.

[0099] The surface of the second roller 73 is located on the +Z direction side, which is vertically above the winding portion Aw. Therefore, when the sheet P1 is being heated by the first roller 72 at 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.

[0100] It can be expected that the vicinity of the upstream end in the conveying direction of the sheet P1 wound around the winding portion Aw is heated from the second surface Fb side by this heated air.

[0101] In order 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 conveying direction. The winding roller 74 winds the sheet P1 formed by the processing roller pair 71 around the first roller 72.

[0102] 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 winding roller 74 of the present embodiment is set to, for example, 20 mm within the range of 6 mm to 40 mm.

[0103] A conveying 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 conveying 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.

[0104] As a result, due to the conveyance by the conveying roller pair 79 and the processing roller pair 71, a winding portion Aw around which the sheet P1 formed at the nip portion An is wound is formed on the first roller 72. Thereby, the pressurization and heating of the web W at the nip portion An and the heating of the sheet P1 at the winding portion Aw can be executed in parallel.

[0105] By heating the first surface Fa side of the sheet P1 in the winding portion Aw by the first roller 72, drying of the sheet P1 is promoted and the moisture contained in the sheet P1 evaporates. By evaporating the moisture contained in the sheet P1, it is possible to suppress deformation and wrinkle generation due to stress during conveyance. 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.

[0106] 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 heating with the first roller 72. Thereby, deformation and conveyance failure downstream in the conveyance direction of the sheet P1 formed by the forming unit 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.

[0107] 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 unit 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.

[0108] By heating 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, moisture evaporation from the sheet P1 in the winding portion Aw is difficult to proceed.

[0109] 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.

[0110] In this case, if the above-described gap, the gap between the pressing rollers 761, 762, and 763 is small, moisture evaporation from the sheet P1 is difficult to proceed 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.

[0111] The plurality of pressing rollers 761, 762, and 763 are arranged at intervals in the conveying direction in this order from the upstream. The pressing rollers 761, 762, and 763 are arranged between the processing roller pair 71 and the winding roller 74 in the conveying path. The pressing rollers 761, 762, and 763 are arranged at positions facing the winding portion Aw in the conveying path.

[0112] The pressing mechanism 75 includes a pressing roller moving portion 77 that can move the pressing rollers 761, 762, and 763 in a direction in which the distance from the surface of the first roller 72 changes.

[0113] The presser roller moving unit 77 includes a presser roller holding unit 77h that holds the presser rollers 761, 762, and 763. The presser roller holding unit 77h moves in the Y-axis direction when the presser roller moving unit 77 is driven and controlled by the control unit 5. The presser roller holding unit 77h is provided so as to be movable in the Y-axis direction while holding the presser rollers 761, 762, and 763. When the presser roller holding unit 77h moves in the Y-axis direction, the positions of the presser rollers 761, 762, and 763 with respect to the first roller 72 are changed.

[0114] The presser rollers 761, 762, and 763 are held by the presser roller holding unit 77h such that their respective rotation axes are movable in a direction in which the distance from the surface of the first roller 72 changes. The respective rotation axes of the presser rollers 761, 762, and 763 are held by the presser roller holding unit 77h in a state of being pressed by a spring 77p in a direction approaching the surface of the first roller 72.

[0115] The spring 77p in the present embodiment is, for example, a compression coil spring. For example, it is assumed that the presser rollers 761, 762, and 763 come into contact with the sheet P1 wound around the first roller 72. In this case, the respective rotation axes of the presser rollers 761, 762, and 763 move in a direction away from the surface of the first roller 72.

[0116] In this case, the spring 77p deforms in the direction in which it is compressed, and a pressing load is generated that presses the respective rotation axes of the presser rollers 761, 762, and 763 in a direction approaching the surface of the first roller 72. The greater the amount of deformation of the spring 77p in the direction in which it is compressed, the greater the pressing load that presses the respective rotation axes of the presser rollers 761, 762, and 763 in a direction approaching the surface of the first roller 72.

[0117] With this configuration, by changing the position of the pressing roller holding part 77h, the pressing load with which the pressing rollers 761, 762, and 763 press the sheet P1 against the first roller 72 can be changed. In other words, the pressing roller moving part 77 includes a spring 77p that changes the pressing load with which the pressing rollers 761, 762, and 763 press the sheet P1 against the first roller 72.

[0118] The pressing roller moving part 77 can move the pressing roller holding part 77h that holds the pressing rollers 761, 762, and 763 to at least a separated position B2, a pressing position B1, and an intermediate position B3.

[0119] When the pressing roller holding part 77h is located at the separated position B2 (see FIGS. 2, 5, and 11), the pressing rollers 761, 762, and 763 are separated from the first roller 72 and the sheet P1 wound around the first roller 72. The pressing rollers 761, 762, and 763 held by the pressing roller holding part 77h located at the separated position B2 are referred to as "the pressing rollers 761, 762, and 763 at the separated position B2".

[0120] The pressing position B1 (see FIG. 3) is the position of the pressing roller holding part 77h when the sheet P1 is being conveyed by the processing roller pair 71 and the conveying roller pair 79 (see FIG. 1).

[0121] The pressing roller holding part 77h located at the pressing position B1 is located on the +Y direction side with respect to the pressing roller holding part 77h located at the separated position B2. The pressing rollers 761, 762, and 763 held by the pressing roller holding part 77h located at the pressing position B1 are referred to as "the pressing rollers 761, 762, and 763 at the pressing position B1".

[0122] The pressing rollers 761, 762, and 763 located at the pressing position B1 move in a direction away from the surface of the first roller 72 when they contact the sheet P1. As a result, a pressing load is generated that presses the sheet P1 toward the winding portion Aw of the first roller 72. In the present embodiment, the pressing load when the pressing rollers 761, 762, and 763 located at the pressing position B1 press the sheet P1 is set between 10 N and 100 N, and is set to 61 N, for example.

[0123] The nip portion Au is formed by the presser roller holding portion 77h being located at the pressing position B1. Each nip portion Au is a pressurized portion that pressurizes the sheet P1 with each of the presser rollers 761, 762, and 763 and the first roller 72. The nip length Lu (not shown) is the dimension in the conveyance direction of the sheet P1 in the nip portion Au.

[0124] Each nip length Lu is the length dimension from the nip start position to the nip end position of the sheet P1 by each of the presser rollers 761, 762, and 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.

[0125] The nip portion Au of the presser roller 762 is located downstream of the center of the winding portion Aw in the conveyance direction. The nip portion Au of the presser roller 761 is located upstream of the center of the winding portion Aw in the conveyance direction. The nip portion Au of the presser roller 763 is located downstream of the center between the downstream end of the winding portion Aw and the nip portion Au of the presser roller 762 in the conveyance direction.

[0126] The rotation axes of the pressing rollers 761, 762, and 763 are arranged along the direction along the X-axis. The pressing rollers 761, 762, and 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 part 77 of the pressing mechanism 75 is arranged on the -Y direction side of the separation position B2.

[0127] The pressing rollers 761, 762, and 763 are driven rollers that are not driven by a drive motor and are interlocked 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, and 763 rotate clockwise.

[0128] 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.

[0129] 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 silicon rubber or urethane rubber as rubber.

[0130] When the rubber hardness of the elastic layer 76e is low, the ratio of the nip portion Au in the winding portion Aw increases. When the ratio 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.

[0131] For this reason, 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 the equilibrium moisture content or less by heating with the first roller 72.

[0132] 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 in rubber hardness.

[0133] 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.

[0134] As the fluororesin, PFA (tetrafluoroethylene - perfluoroalkyl vinyl ether copolymer) or PTFE (polytetrafluoroethylene) can be adopted. As other fluororesins, FEP (tetrafluoroethylene - hexafluoropropylene copolymer), ETFE (tetrafluoroethylene - ethylene copolymer), etc. can be adopted. By providing the surface layer 76s, the non - adhesiveness to the web W and the sheet P1 can be enhanced. By providing the surface layer 76s, wear and damage of the shaft 76c can be suppressed.

[0135] The sheet P1 is formed by pressurizing and heating the web W in the nip portion An. Therefore, the pressing load of the pressing rollers 761, 762, and 763 that press the sheet P1 toward the first roller 72 may be smaller than the pressing load of the second roller 73 that presses the web W toward the first roller 72. The pressing load of each pressing roller 761, 762, and 763 in the present embodiment is in the range of 20 N to 80 N, and is set to 60 N, for example.

[0136] As a result, the pressure acting on the sheet P1 when the pressing rollers 761, 762, and 763 press the sheet P1 toward the first roller 72 is smaller than the pressure acting on the web W when the processing roller pair 71 nips the web W.

[0137] The pressing rollers 761, 762, and 763 of the present 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, and 763 of the present 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, and 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, and 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, and 763. In this case, as the pressing rollers 761, 762, and 763, forms such as stepped rollers or split rollers can also be used.

[0138] The intermediate position B3 (see FIGS. 6 to 10) is the position of the pressing roller holding portion 77h when the sheet P1 is being conveyed by the processing roller pair 71 and has not been conveyed to the conveying roller pair 79. The intermediate position B3 (see FIGS. 6 to 10) is the position of the pressing roller holding portion 77h when the leading end of the sheet P1 passes between the pressing rollers 761, 762, and 763 and the first roller 72 in the leading end passing process described later.

[0139] The pressing roller holding portion 77h is located at the intermediate position B3 until the leading end of the sheet P1 in the leading end passing process reaches the conveying roller pair 79 (see FIG. 1). The pressing rollers 761, 762, and 763 held by the pressing roller holding portion 77h located at the intermediate position B3 are referred to as "the pressing rollers 761, 762, and 763 at the intermediate position B3".

[0140] The pressing rollers 761, 762, and 763 at the intermediate position B3 move in a direction away from the surface of the first roller 72 when they contact the sheet P1. As a result, a pressing load is generated that presses the sheet P1 toward the winding portion Aw of the first roller 72 by the pressing rollers 761, 762, and 763.

[0141] Assume that the leading edge of the sheet P1 enters between the pressing rollers 761, 762, 763 and the first roller 72 when being conveyed to the processing roller pair 71. At this time, it is desirable that the pressing rollers 761, 762, 763 are in a state where they easily move in a direction away from the first roller 72 following the entry into the nip portion Au at the leading edge of the sheet P1. Assume that the pressing rollers 761, 762, 763 are in contact with the sheet P1 when being conveyed by the processing roller pair 71 and not being conveyed by the conveying roller pair 79. In this case, if the pressing load when the pressing rollers 761, 762, 763 at the pressing position B1 are in contact with the sheet P1 acts on the sheet P1, there is a risk of deformation such as wrinkles occurring in the sheet P1.

[0142] Therefore, the pressing load when the pressing rollers 761, 762, 763 at the intermediate position B3 are in contact with the sheet P1 is set to be smaller than when the pressing rollers 761, 762, 763 are at the pressing position B1. Thus, the intermediate position B3 is located between the separation position B2 and the pressing position B1 in the Y-axis direction.

[0143] In the present embodiment, the pressing load when the pressing rollers 761, 762, 763 at the intermediate position B3 are in contact with the sheet P1 is set to be not less than 0.01 N and less than 10 N. The smaller the pressing load when the pressing rollers 761, 762, 763 are in contact with the sheet P1, the smaller the amount by which the elastic layer 76e of the pressing rollers 761, 762, 763 and the sheet P1 are compressed.

[0144] Therefore, for example, it is assumed that the pressing rollers 761, 762, and 763 at the intermediate position B3 are in contact with the sheet P1. At this time, the positions of the pressing rollers 761, 762, and 763 at the intermediate position B3 are located on the -Y direction side from the positions when the pressing rollers 761, 762, and 763 at the pressing position B1 are in contact with the sheet P1.

[0145] For example, it is assumed that the sheet P1 is nipped between the pressing rollers 761, 762, and 763 at the intermediate position B3 in contact with the first roller 72 and the first roller 72. As a result, the pressing load acting on the sheet P1 is smaller than the pressing load acting on the sheet P1 when the pressing rollers 761, 762, and 763 at the pressing position B1 press the sheet P1 toward the first roller 72.

[0146] 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-like 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. By the tip of the peeling plate coming into contact with 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.

[0147] The peeling portion 78 includes a peeling plate moving portion (not shown) that is movable 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 moving portion by the control unit 5.

[0148] 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 the set temperatures. When forming the web W into the sheet P1, the driving of the second roller displacement unit is controlled by the control unit 5, so that the second roller 73 is positioned at the nip position.

[0149] 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 unit 77 is controlled by the control unit 5, so that the pressing roller holding unit 77h is positioned at the pressing position B1. When forming the web W into the sheet P1, the driving of the peeling plate moving unit is controlled by the control unit 5, so that the peeling plate is positioned at the retracted position C2.

[0150] Next, referring to the flowchart shown in FIG. 4, the leading edge passing process executed by the control unit 5 when the leading edges of the web W and the sheet P1 pass through the forming unit 70 in the forming of the sheet P1 will be described. In the present embodiment, when the leading edges of the web W and the sheet P1 pass through the forming unit 70, the flow of the process in the leading edge passing process executed by the control unit 5 corresponds to the sheet manufacturing method.

[0151] In the leading edge passing process, the control unit 5 controls the pressing roller moving unit 77 based on the temperatures of the first roller 72 and the second roller 73, the rotation state of the first roller 72, and the positions of the leading edges of the web W and the sheet P1. Thereby, in the leading edge passing process, the control unit 5 changes the positions of the pressing roller holding unit 77h and the pressing rollers 761, 762, and 763.

[0152] For example, assume that the sheet manufacturing apparatus 1 is in the state immediately after startup or in a standby state. At this time, since the heaters 72h and 73h are not driven, the surface temperatures of the first roller 72 and the second roller 73 are not at the set temperature. At this time, since the first roller 72 is not driven, it is not rotating. At this time, the second roller 73 is located at the nip release position. At this time, the presser roller holding portion 77h that holds the presser rollers 761, 762, and 763 is located at the separated position B2. At this time, the peeling portion 78 is located at the retracted position C2. Here, the case of performing the tip passing process from this state will be described.

[0153] In step S110, the control unit 5 executes a warming-up operation. In the warming-up operation, the control unit 5 drives the heaters 72h and 73h to raise the surface temperatures of the first roller 72 and the second roller 73. Subsequently, the control unit 5 controls the second roller displacement unit to move the second roller 73 from the nip release position to the nip position. Subsequently, as shown in FIG. 5, the control unit 5 rotates the first roller 72 counterclockwise when viewed from the -X direction side. As a result, the second roller 73 rotates clockwise when viewed from the -X direction side.

[0154] When the temperature detection units 72t and 73t detect that the surface temperatures of the first roller 72 and the second roller 73 have reached the set temperature, the control unit 5 drives and controls the presser roller moving unit 77 and the peeling unit moving unit. As a result, as shown in FIG. 6, the presser roller holding portion 77h that holds the presser rollers 761, 762, and 763 moves to the intermediate position B3, and the peeling portion 78 moves to the contact position C1.

[0155] In other words, when the first roller 72 is rotating and the temperatures of the first roller 72 and the second roller 73 have reached the set temperature, the control unit 5 brings the presser rollers 761, 762, and 763 into contact with the first roller 72. After finishing the process of step S110, the control unit 5 shifts the process to step S120.

[0156] In step S120, the control unit 5 creates a tip in the tip passing process of the web W. Specifically, as shown in FIG. 7, the control unit 5 rotates the first roller 72 clockwise when viewed from the -X direction side. As a result, the second roller 73 at the nip position rotates counterclockwise when viewed from the -X direction side. Next, the control unit 5 drives the second conveyance unit 62 (see FIG. 1) to convey the tip of the web W downstream in the conveyance direction.

[0157] As a result, as shown by the white arrow in FIG. 8, the tip of the web W is wound around and folded onto the rotating first roller 72. By folding the tip of the web W, the tip in the tip passing process of the web W is created.

[0158] While the process of step S120 is being executed, the temperatures of the surfaces of the first roller 72 and the second roller 73 are maintained at the set temperature. After finishing the process of step S120, the control unit 5 shifts the process to step S130.

[0159] In step S130, the control unit 5 executes preparatory conveyance of the web W and the sheet P1. Specifically, as shown in FIG. 9, the control unit 5 rotates the first roller 72 counterclockwise when viewed from the -X direction side. As a result, the second roller 73 at the nip position rotates clockwise when viewed from the -X direction side. By the rotating first roller 72 and second roller 73, the tip in the tip passing process of the web W is conveyed to the nip portion An and formed into the sheet P1 in the tip passing process.

[0160] The tip of the sheet P1 in the tip passing process passes between the rotating first roller 72 and the pressing rollers 761, 762, 763 at the intermediate position B3. As a result, as shown in FIG. 10, the sheet P1 in the tip passing process is wound around the winding portion Aw of the first roller 72. In other words, the control unit 5 winds the sheet P1 around the first roller 72 with the pressing rollers 761, 762, 763 in contact with the winding portion Aw.

[0161] Furthermore, by the rotating first roller 72 and second roller 73, that is, the rotating pair of processing rollers 71, the control unit 5 conveys the sheet P1 in the downstream direction of the conveyance direction in the leading-edge passing process. As a result, the sheet P1 in the leading-edge passing process is conveyed toward the pair of conveyance rollers 79 via the winding roller 74.

[0162] While the process of step S130 is being executed, the temperature of the surfaces of the first roller 72 and the second roller 73 is maintained at the set temperature. When the process of step S130 is finished, the control unit 5 shifts the process to step S140.

[0163] In step S140, the control unit 5 checks whether the leading edge of the sheet P1 in the leading-edge passing process has been detected by the sheet detection sensor 87. When the sheet detection sensor 87 detects the sheet P1, the control unit 5 determines that the sheet P1 has reached the pair of conveyance rollers 79. When the sheet detection sensor 87 does not detect the sheet P1, the control unit 5 determines that the sheet P1 has not reached the pair of conveyance rollers 79.

[0164] When the sheet detection sensor 87 detects the sheet P1, step S140 becomes YES, and the control unit 5 shifts the process to step S150. When the sheet detection sensor 87 does not detect the sheet P1, step S140 becomes NO, and the control unit 5 continues to detect the sheet P1 in step S140.

[0165] While the process of step S140 is being executed, the temperature of the surfaces of the first roller 72 and the second roller 73 is maintained at the set temperature. The conveyance of the sheet P1 in step S140 is performed by the rotation of the pair of processing rollers 71.

[0166] When the process proceeds to step S150, the control unit 5 rotates the first roller 72 and the second roller 73, and thus it is considered that the conveyance roller pair 79 conveys the sheet P1 until the leading edge of the sheet P1 reaches. Note that, at any timing before the sheet P1 reaches the conveyance roller pair 79, the control unit 5 rotates the conveyance roller pair 79 in the direction of conveying the sheet P1 downstream in the conveyance direction.

[0167] In step S150, the control unit 5 executes the movement of the pressing rollers 761, 762, and 763 to the separated position B2. In other words, the control unit 5 changes the positions of the pressing rollers 761, 762, and 763 based on the position of the leading edge of the sheet P1. Specifically, the control unit 5 drives and controls the pressing roller moving unit 77 and the peeling unit moving unit based on the position of the leading edge of the sheet P1 detected in step S140.

[0168] As a result, as shown in FIG. 11, the control unit 5 moves the pressing roller holding unit 77h that holds the pressing rollers 761, 762, and 763 to the separated position B2, and moves the peeling unit 78 to the retracted position C2.

[0169] In other words, when the leading edge of the sheet P1 reaches the conveyance roller pair 79, the control unit 5 separates the pressing rollers 761, 762, and 763 from the sheet P1 wound around the first roller 72. Thereby, it is suppressed that the sheet P1 in which deformation such as wrinkles has occurred is conveyed. The control unit 5 positions the pressing rollers 761, 762, and 763 at the separated position B2 for a predetermined time, for example, 2 seconds or more. Thereby, it is further suppressed that the sheet P1 in which deformation such as wrinkles has occurred is conveyed.

[0170] While the process of step S150 is being executed, the conveyance of the sheet P1 by the rotation of the process roller pair 71 and the conveyance roller pair 79 is continued. When the process of step S150 is finished, the control unit 5 proceeds with the process to step S160.

[0171] In step S160, the control unit 5 executes the movement of the pressing rollers 761, 762, and 763 to the pressing position B1. Specifically, the control unit 5 drives and controls the pressing roller moving unit 77. As a result, as shown in FIG. 12, the control unit 5 moves the pressing roller holding unit 77h that holds the pressing rollers 761, 762, and 763 to the pressing position B1.

[0172] In other words, in step S160, the control unit 5 causes the pressing rollers 761, 762, and 763 that have been separated from the sheet P1 for a predetermined time to come into contact with the sheet P1 wound around the first roller 72 again. After finishing the process of step S160, the control unit 5 ends the leading edge passing process.

[0173] While the process of step S160 is being executed, the conveyance of the sheet P1 by the rotation of the processing roller pair 71 and the conveyance roller pair 79 is continued. While the process of step S160 is being executed, the temperatures of the surfaces of the first roller 72 and the second roller 73 are maintained at the set temperature. In this state, assume that the leading edge of the sheet P1 has reached the conveyance roller pair 79. In this case, the control unit 5 presses the sheet P1 wound around the first roller 72 against the first roller 72 by the pressing rollers 761, 762, and 763 at the pressing position B1.

[0174] After the leading edge passing process, the conveyance of the sheet P1 by the rotation of the processing roller pair 71 and the conveyance roller pair 79 is continued, so that the sheet P1 formed from the web W by the forming unit 70 is conveyed toward the first unit group 101.

[0175] As described above, according to the sheet manufacturing apparatus 1 and the sheet manufacturing method according to Embodiment 1, the following effects can be obtained.

[0176] The sheet manufacturing apparatus 1 includes a deposition unit 50 that forms a web W by depositing a material containing fibers, a forming unit 70 that forms the web W into a sheet P1 by pressurizing and heating it, and a control unit 5. The forming unit 70 has 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 has pressing rollers 761, 762, 763 that press the sheet P1 wound around the first roller 72 toward the first roller 72. The forming unit 70 has a pressing roller moving unit 77 that changes the positions of the pressing rollers 761, 762, 763. The control unit 5 controls the pressing roller moving unit 77 based on the position of the leading end, which is the downstream end in the conveyance direction of the sheet P1.

[0177] According to this, when the leading end of the sheet P1 is conveyed, it is possible to suppress the occurrence of deformation such as wrinkles in the sheet P1 and poor conveyance of the sheet P1. As a result, it is possible to suppress the occurrence of deformation such as wrinkles in the sheet P1 formed by the forming unit 70. Thereby, it is possible to suppress the occurrence of poor conveyance of the sheet P1 formed by the forming unit 70.

[0178] The pressing roller moving unit 77 includes a spring 77p that changes the pressing load with which the pressing rollers 761, 762, 763 press the sheet P1 against the first roller 72. According to this, by controlling the pressing roller moving unit 77, it is possible to change the pressing load with which the pressing rollers 761, 762, 763 press the sheet P1 against the first roller 72.

[0179] The sheet manufacturing method is a sheet manufacturing method in which a web W formed by depositing a material containing fibers is pressed and heated to form a sheet P1. The sheet manufacturing method includes forming the web W into the sheet P1 by rotating the first roller 72 while nipping the web W between the heated first roller 72 and the second roller 73. The sheet manufacturing method includes pressing the sheet P1 wound around the first roller 72 against the first roller 72 by the pressing rollers 761, 762, 763 at the pressing position B1. In this state, the sheet manufacturing method includes conveying downstream in the conveying direction in which the sheet P1 is conveyed. The sheet manufacturing method changes the positions of the pressing rollers 761, 762, 763 based on the temperature of the first roller 72, the rotation state of the first roller 72, and the position of the tip, which is the downstream end of the sheet P1.

[0180] According to this, it is possible to suppress the occurrence of deformation such as wrinkles in the sheet P1 and poor conveyance of the sheet P1 when the tip of the sheet P1 is conveyed. As a result, it is possible to suppress the occurrence of deformation such as wrinkles in the sheet P1 formed by the forming unit 70. Thereby, it is possible to suppress the occurrence of poor conveyance of the sheet P1 formed by the forming unit 70.

[0181] Assume that the first roller 72 is rotating, the temperature of the first roller 72 is the set temperature, and the tip of the sheet P1 has reached the pair of conveying rollers 79 that convey the sheet P1 downstream of the first roller 72. In this case, the sheet manufacturing method presses the sheet P1 wound around the first roller 72 against the first roller 72 by the pressing rollers 761, 762, 763 at the pressing position B1.

[0182] According to this, the sheet P1 with tension applied is conveyed while being pressed against the first roller 72 by the pressing rollers 761, 762, 763 at the pressing position B1. Thereby, it is possible to suppress the occurrence of deformation such as wrinkles in the sheet P1 formed by the forming unit 70. Therefore, it is possible to suppress the occurrence of poor conveyance of the sheet P1 formed by the forming unit 70.

[0183] Assume that the first roller 72 is rotating and the temperature of the first roller 72 has reached the set temperature. In this case, the sheet manufacturing method brings the pressing rollers 761, 762, and 763 into contact with the first roller 72. According to this, before the tip of the formed sheet P1 reaches the winding portion Aw of the first roller 72, the pressing rollers 761, 762, and 763 can be brought into contact with the first roller 72.

[0184] The sheet manufacturing method winds the sheet P1 around the first roller 72 with the pressing rollers 761, 762, and 763 in contact therewith. According to this, the tip of the formed sheet P1 is guided by the pressing rollers 761, 762, and 763, so that the sheet P1 is wound along the surface of the first roller 72. Thereby, when the sheet P1 is wound around the first roller 72, it is possible to suppress the occurrence of deformations such as wrinkles in the sheet P1. Therefore, it is possible to suppress the occurrence of conveyance failure of the sheet P1 formed by the forming unit 70.

[0185] Assume that the tip of the sheet P1 has reached the conveying roller pair 79 that conveys the sheet P1 downstream of the first roller 72. In this case, the sheet manufacturing method separates the pressing rollers 761, 762, and 763 from the sheet P1 wound around the first roller 72. Thereafter, the sheet manufacturing method brings the pressing rollers 761, 762, and 763 into contact with the sheet P1 wound around the first roller 72 again.

[0186] According to this, before the sheet P1 reaches the conveying roller pair 79, the deformations such as wrinkles generated in the sheet P1 are eliminated. Thereafter, by bringing the pressing rollers 761, 762, and 763 into contact with the sheet P1 wound around the first roller 72 again, it is possible to suppress the occurrence of deformations such as wrinkles in the sheet P1 formed by the forming unit 70. Therefore, it is possible to suppress the occurrence of conveyance failure of the sheet P1 formed by the forming unit 70.

[0187] Assume that the tip of the sheet P1 is nipped between the pressing rollers 761, 762, 763 in contact with the first roller 72 and the first roller 72. At this time, the pressing load acting on the sheet P1 is smaller than the pressing load acting on the sheet P1 when the pressing rollers 761, 762, 763 at the pressing position B1 press the sheet P1 toward the first roller 72.

[0188] According to this, compared with the pressing rollers 761, 762, 763 at the pressing position B1 and the first roller 72, the tip of the sheet P1 can easily enter between the pressing rollers 761, 762, 763 and the first roller 72. Thereby, when the sheet P1 is wound around the first roller 72, it is possible to suppress the occurrence of deformation such as wrinkles in the sheet P1. Further, it is possible to suppress the occurrence of deformation such as wrinkles in the sheet P1 in a state where the sheet P1 is not conveyed to the conveying roller pair 79. Therefore, it is possible to suppress the occurrence of conveyance failure of the sheet P1 formed by the forming unit 70.

[0189] The sheet manufacturing apparatus 1 according to the first embodiment 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 first embodiment and other embodiments described below can be implemented in combination with each other within a range where there is no technical contradiction. Hereinafter, other embodiments will be described.

[0190] In the above-described first embodiment, the nip portion Au of the pressing roller 762 may be located at the center of the winding portion Aw in the conveyance direction of the sheet P1. In this case, the winding portion Aw may be evenly divided into four sections in the conveyance direction by the nip portions Au of the respective pressing rollers 761, 762, 763.

[0191] In the above Embodiment 1, the forming unit 70 does not necessarily include the three pressing rollers 761, 762, and 763. The forming unit 70 may include any two of the three pressing rollers 761, 762, and 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 one 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.

[0192] In the above Embodiment 1, the forming unit 70 may include a middle support portion for reducing the deflection generated in the pressing rollers 761, 762, and 763 at the pressing position B1. For example, the middle 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 at 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.

[0193] In the above Embodiment 1, the outer diameters of the pressing rollers 761, 762, and 763 do not necessarily have to 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.

[0194] In the above-described Embodiment 1, the rubber hardness of the elastic layers 76e of the pressing rollers 761, 762, and 763 does not have to 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 other one elastic layer 76e 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 76e of the pressing roller 763 may be lower than the rubber hardness of the elastic layers 76e of the pressing rollers 761 and 762.

[0195] 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.

[0196] In the above-described Embodiment 1, the forming unit 70 may include a guide unit that guides the leading end of the sheet P1 peeled from the first roller 72 downstream in the conveyance direction by the peeling unit 78 in the leading end passing process. The guide unit may be provided in the forming unit 70 so as to be movable between a guide position for guiding the leading end of the sheet P1 and a standby position away from the first roller 72. In this case, for example, in step S110 in the leading end passing process shown in FIG. 4, the control unit 5 moves the guide unit to the guide position. Then, after executing the movement of the pressing rollers 761, 762, and 763 to the pressing position B1 in step S160, the control unit 5 positions the guide unit at the standby position.

[0197] According to this, it is possible to suppress the occurrence of dew condensation in the guide portion due to the temperature change in the atmosphere of the first roller 72. The timing for moving the guide portion from the guide position to the standby position in the leading end passing process may be the same as the timing for executing the movement of the pressing rollers 761, 762, 763 to the separated position B2 in step S150.

[0198] In the above-described Embodiment 1, if it is possible to generate a pressing load for pressing the sheet P1 by the pressing rollers 761, 762, 763, the spring 77p does not have to be a compression coil spring. For example, the spring 77p may be a tension coil spring. In this case, for example, a lever that supports each rotation axis of the pressing rollers 761, 762, 763 at one end is provided. This lever is supported by the pressing roller holding portion 77h so as to be rotatable about an axis along the X axis. One hook of the tension coil spring is hooked on the other end of this lever. The other hook of the tension coil spring is hooked on the pressing roller holding portion 77h. Thereby, each rotation axis of the pressing rollers 761, 762, 763 is offset in a direction approaching the surface of the first roller 72.

[0199] In the above-described Embodiment 1, if it is possible to generate a pressing load for pressing the sheet P1 by the pressing rollers 761, 762, 763 due to the compression deformation of the elastic layer 76e, the spring 77p does not have to be provided. In this case, each rotation axis of the pressing rollers 761, 762, 763 does not have to be held by the pressing roller holding portion 77h so as to be movable in a direction in which the distance from the first roller 72 of the pressing rollers 761, 762, 763 changes.

[0200] In the leading end passing process in the above-described Embodiment 1, if the sheet P1 can be wound around the winding portion Aw, the pressing rollers 761, 762, 763 at the intermediate position B3 do not have to contact the sheet P1. In this case, for example, the pressing rollers 761, 762, 763 at the intermediate position B3 may be positioned at a position separated from the winding portion Aw by the thickness of the sheet P1.

[0201] In the tip passing process in the above-described Embodiment 1, the pressing load when the pressing rollers 761, 762, and 763 are in contact with the sheet P1 may be the same as when the pressing rollers 761, 762, and 763 are at the pressing position B1. In this case, it is assumed that the tip of the sheet P1 is nipped between the pressing rollers 761, 762, and 763 in contact with the first roller 72 and the first roller 72. The pressure acting on the sheet P1 at this time becomes the same as the pressure acting on the sheet P1 when the pressing rollers 761, 762, and 763 at the pressing position B1 press the sheet P1 toward the first roller 72.

[0202] In this case, in the tip passing process, the control unit 5 may not position the pressing roller holding unit 77h at the intermediate position B3. In this case, for example, in step S110 in the tip passing process shown in FIG. 4, the control unit 5 brings the pressing rollers 761, 762, and 763 at the pressing position B1 into contact with the first roller 72.

[0203] In the tip passing process in the above-described Embodiment 1, the control unit 5 may drive and control the pressing roller moving unit 77 and the peeling unit moving unit even if the surface temperatures of the first roller 72 and the second roller 73 have not reached the set temperature. In this case, in the warming-up operation, the control unit 5 drives the heaters 72h and 73h to raise the surface temperatures of the first roller 72 and the second roller 73. Then, for example, the control unit 5 predicts the time required until the surface temperatures of the first roller 72 and the second roller 73 reach the set temperature.

[0204] The control unit 5 drives and controls the presser roller moving unit 77 and the peeling unit moving unit based on the time required to reach the predicted set temperature, before the temperatures of the surfaces of the first roller 72 and the second roller 73 reach the set temperature. As a result, the presser roller holding unit 77h moves to the intermediate position B3, and the presser rollers 761, 762, 763 come into contact with the first roller 72 whose surface temperature has reached the set temperature. Further, the peeling unit 78 moves to the contact position C1, and the tip of the peeling plate comes into contact with the first roller 72 whose surface temperature has reached the set temperature. According to this, the time required for the warming-up operation in the tip passing process can be shortened.

Explanation of Signs

[0205] 1... Sheet manufacturing apparatus, 5... Control unit, 11... Raw material inlet, 13... Buffer tank, 15... Quantitative supply unit, 15a... Meter, 17... Confluence section, 21, 23, 24, 25... Pipes, 22... Fiber conveyance pipe, 30... Defibrator, 31... Tension roller, 32... Roller, 40... Separator, 50... Deposition section, 51... Housing, 53... Drum member, 55... Blade member, 59... Suction section, 61... First conveyance section, 61a... First conveyance belt, 62... Second conveyance section, 62a... Second conveyance belt, 65... First humidifying section, 66... Second humidifying section, 67... Water supply section, 68... Drainage section, 70... Forming section, 71... Treatment roller pair, 72... First roller, 72c... Mandrel, 72h... Heater, 72s... Surface layer, 72t... Temperature detection section, 73... Second roller, 73c... Mandrel, 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 section, 77h... Pressing roller holding section, 77p... Spring, 78... Peeling section, 79... Conveyance roller pair, 81... First cutting section, 82... Second cutting section, 84... Tray, 86... Shredding section, 91... Mixing section, 95... Recovery section, 97... Compressor, 99... Power supply section, 101... First unit group, 102... Second unit group, 103... Third unit group, 201... Cleaning section, 451... Airflow pipe, 761, 762, 763... Pressing rollers, An... nip section, Au... nip section, Aw... Wrapping portion, B1... Pressing position, B2... Separation position, B3... Intermediate position, C1... Contact position, C2... Retraction position, Fa... First surface, Fb... Second surface, Ln... nip length, Lu... nip length, Lw... Wrapping length, P1, P2, P3... Sheets, S110, S120, S130, S140, S150, S160... Steps.

Claims

1. A depositing 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, A control unit, Comprising, The forming unit is, 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 winding roller provided downstream of the first roller in the conveyance direction in which the sheet is conveyed, and winding the sheet around the first roller, A pressing roller that presses the sheet wound around the first roller toward the first roller, A pressing roller moving unit that changes the position of the pressing roller, Having, The control unit controls the pressing roller moving unit based on the position of the leading end, which is the downstream end of the sheet in the conveyance direction of the sheet. A sheet manufacturing apparatus characterized by the above.

2. The pressing roller moving unit includes a spring that changes the pressing load with which the pressing roller presses the sheet against the first roller. The sheet manufacturing apparatus according to claim 1, characterized by the above.

3. A sheet manufacturing method of forming a sheet by pressing and heating a web formed by depositing a material containing fibers, Rotating the first roller while nipping the web between the heated first roller and the second roller to form the web into the sheet, Conveying the sheet wound around the first roller downstream in the conveyance direction in which the sheet is conveyed while pressing the sheet wound around the first roller against the first roller by a pressing roller at a pressing position, Including, Changing the position of the pressing roller based on the temperature of the first roller, the rotation state of the first roller, and the position of the leading end, which is the downstream end of the sheet. A sheet manufacturing method characterized by the above.

4. When the first roller is rotating, the temperature of the first roller is at a set temperature, and the leading end of the sheet has reached a pair of conveying rollers that convey the sheet downstream of the first roller, Pressing the sheet wound around the first roller against the first roller by the pressing roller at the pressing position. The sheet manufacturing method according to claim 3, characterized by the above.

5. When the first roller is rotating and the temperature of the first roller reaches the set temperature, bringing the pressing roller into contact with the first roller; The sheet manufacturing method according to claim 3, characterized by the above.

6. wrapping the sheet around the first roller with the pressing roller in contact therewith; The sheet manufacturing method according to claim 5, characterized by the above.

7. when the leading end of the sheet reaches a pair of conveying rollers that convey the sheet downstream of the first roller, after separating the pressing roller from the sheet wound around the first roller, bringing the pressing roller into contact with the sheet wound around the first roller again; The sheet manufacturing method according to claim 5, characterized by the above.

8. The pressing load acting on the sheet when the leading end of the sheet is nipped between the pressing roller in contact with the first roller and the first roller is smaller than the pressing load acting on the sheet by the pressing roller pressing the sheet toward the first roller at the pressing position; The sheet manufacturing method according to any one of claims 5 to 7, characterized by the above.

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