Sheet manufacturing device

Abstract

To provide a sheet manufacturing device that prevents defects due to thickness of a web tip from occurring and can be easily downsized.SOLUTION: A sheet manufacturing device 1 comprises: a defibration machine; an accumulation part to form a web; and a sheet molding part 70 that has first and second rollers 71, 72 and forms a belt-like sheet by pressurizing the web. The sheet molding part comprises: a first roller holding unit 711 on which the first roller is installed; a drive motor 79; a gear G4 to which rotation of the drive motor is transmitted so as to rotate the second roller; a first transmission gear G5a to which rotation of the gear G4 is transmitted; a one-way clutch gear G5b installed on the same rotation axis as the first transmission gear; a gear G7 to which rotation of the one-way clutch gear is transmitted; a cam C17 installed on the same axis as the gear G7; and a pin 735 to position the first roller holding unit by abutting against the cam. The first transmission gear has an idling mechanism capable of idling for a certain period.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a sheet manufacturing apparatus. [Background technology]

[0002] Conventionally, there have been known devices that manufacture sheets using fibers obtained by defibrating waste paper or the like in air. Among such devices, there are devices that mold a sheet from a web containing fibers. For example, Patent Document 1 discloses a sheet manufacturing device that includes a pair of rollers for pressing or the like to mold a web into a sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-208923 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the device described in Patent Document 1, when the thickness of the web tip is thin, there is a possibility that the device may malfunction. In particular, in the process of forming a web by depositing materials such as fibers in the air, there is a problem that it is difficult to control the thickness of the web tip. When the thickness of the web tip becomes thin, the web may stick to the heating roller. In addition, the thickness of the tip of the sheet formed from the web also becomes thin, so that the mechanical strength of the sheet tip is insufficient and buckling is likely to occur. In other words, in the sheet transport path, the sheet tip may get caught on a member such as a transport roller, causing a paper jam. The following invention was devised to solve the above-mentioned problems without increasing the size of the device or the number of parts. [Means for solving the problem]

[0005] The sheet manufacturing apparatus comprises: a defibrator that defibrates a fiber-containing material to produce defibrated material; a deposition unit that deposits the defibrated material to form a web; and a sheet forming unit that has a first roller and a second roller and pressurizes the web to form a sheet, the sheet forming unit comprising a first roller holding unit on which the first roller is installed; a drive motor that can rotate in forward and reverse directions; a second roller gear to which the rotation of the drive motor is transmitted to rotate the second roller; a first transmission gear to which the rotation of the second roller gear is transmitted; a one-way clutch gear that is installed on the same rotation axis as the first transmission gear; a cam gear to which the rotation of the one-way clutch gear is transmitted; a cam that is installed coaxially with the cam gear; and a pin that is fixed to the first roller holding unit and positions the first roller holding unit by abutting against the cam, and the first transmission gear comprises an idling mechanism that can rotate idly for a certain period of time. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of a sheet manufacturing apparatus according to an embodiment. [Diagram 2] FIG. 1 is a flow diagram showing a web folding operation. [Diagram 3] FIG. 2 is a schematic diagram showing a method of folding a web. [Figure 4] FIG. 2 is a schematic diagram showing a method of folding a web. [Diagram 5] FIG. 2 is a schematic diagram showing a method of folding a web. [Figure 6] FIG. 2 is a schematic diagram showing a method of folding a web. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. 4 is a perspective view showing an arrangement of a first roller holding unit and a first roller. [Figure 10] FIG. 4 is a perspective cross-sectional view showing the arrangement of a first transmission gear, a one-way clutch gear, and the like. [Figure 11]FIG. 4 is a cross-sectional perspective view showing the arrangement of a cam gear, a cam, and a cam connecting shaft. [Figure 12] FIG. 4 is a perspective view showing a configuration of an idling mechanism of a first transmission gear. [Figure 13] FIG. [Figure 14] FIG. [Figure 15] FIG. 4 is a side view showing a state in which the sheet forming unit is at rest. [Figure 16] FIG. 4 is a side view showing an operation preparation operation in the sheet forming unit. [Figure 17] FIG. 4 is a side view showing an operation preparation operation in the sheet forming unit. [Figure 18] FIG. 11 is a side view showing a web folding operation in the sheet forming section. [Figure 19] 11 is a side view showing a web folding operation and a sheet forming operation in the sheet forming section. FIG. [Figure 20] FIG. 11 is a side view showing a pre-stop operation in the sheet forming section. [Figure 21] FIG. 11 is a side view showing a pre-stop operation in the sheet forming section. [Figure 22] FIG. 11 is a side view showing a pre-stop operation in the sheet forming section. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] In the following embodiment, a sheet manufacturing apparatus 1 that recycles waste paper or the like into a sheet in a dry manner is exemplified as the sheet manufacturing apparatus of the present invention. The sheet manufacturing apparatus 1 will be described below with reference to the drawings. Note that the sheet manufacturing apparatus of the present invention is not limited to being of a dry type, and may be of a wet type. In this specification, the term "dry type" refers to being carried out in air such as the atmosphere, rather than in a liquid.

[0008] In each of the following figures, XYZ axes are attached as mutually orthogonal coordinate axes, the direction indicated by each arrow is the + direction, and the direction opposite to the + direction is the - direction. The Z axis is an imaginary axis along the vertical direction, with the +Z direction being the upward direction and the -Z direction being the downward direction. The -Z direction is the direction in which gravity acts. In addition, in the sheet manufacturing apparatus 1, the side ahead in the conveying direction of the raw material, web, sheet, etc. is sometimes referred to as the downstream side, and the side going upstream in the conveying direction is sometimes referred to as the upstream side. For convenience of illustration, the sizes of each component are made different from the actual size.

[0009] In this specification, the first direction refers to a counterclockwise rotation direction when viewed from the side in the -X direction, and the second direction is the opposite direction to the first direction and refers to a clockwise rotation direction when viewed from the side in the -X direction.

[0010] 1.Sheet manufacturing equipment As shown in Fig. 1, the sheet manufacturing apparatus 1 according to this embodiment includes a first unit group 101, a second unit group 102, and a third unit group 103. The first unit group 101, the second unit group 102, and the third unit group 103 are supported by a frame (not shown). In Fig. 1, the directions in which waste paper C, sheets P3, slit pieces S, unnecessary scraps, etc. move are indicated by outlined arrows.

[0011] The sheet manufacturing apparatus 1 manufactures a sheet P3 from recycled paper C, which is a material containing fibers. In the sheet manufacturing apparatus 1, a first unit group 101, a third unit group 103, and a second unit group 102 are arranged from the -Y direction toward the +Y direction in a side view from the -X direction.

[0012] The waste paper C is transported from the first unit group 101 to the second unit group 102 via a pipe 21 that crosses inside the third unit group 103. The waste paper C is then defibrated and turned into fibers in the second unit group 102, and made into a mixture containing a binder and the like. The mixture is transported to the third unit group 103 via a pipe 24. The mixture is made into a web W in the third unit group 103, and is then formed into a belt-shaped sheet P1. The belt-shaped sheet P1 is cut in the first unit group 101 to become a sheet P3.

[0013] The first unit group 101 has a buffer tank 13, a constant quantity supply unit 15, a junction unit 17, and a pipe 21. In the first unit group 101, these components are arranged in the above order from upstream to downstream. The first unit group 101 also has a first cutting unit 81, a second cutting unit 82, a tray 84, and a shredding unit 86. The first cutting unit 81 and the second cutting unit 82 cut the strip-shaped sheet P1 into a sheet P3 of a predetermined shape. The first unit group 101 also has a water supply unit 67. The water supply unit 67 is a water storage tank. The water supply unit 67 supplies water for humidification to each of the first humidifying unit 65 and the second humidifying unit 66, which will be described later, through a water supply pipe (not shown).

[0014] Waste paper C is fed into the buffer tank 13 from the raw material feed port 11. The waste paper C contains fibers such as cellulose, and is, for example, pieces of shredded waste paper. Humidified air is supplied to the inside of the buffer tank 13 from the second humidifier 66 provided in the third unit group 103.

[0015] The waste paper C to be defibrated is temporarily stored in the buffer tank 13, and then transported to the fixed-quantity supply unit 15 in accordance with the operation of the sheet manufacturing apparatus 1. The sheet manufacturing apparatus 1 may be equipped with a shredder upstream of the buffer tank 13 that shreds the waste paper C and the like.

[0016] The fixed-quantity supply unit 15 has a weighing device 15a and a supply mechanism (not shown). The weighing device 15a weighs the mass of the waste paper C. The supply mechanism supplies the waste paper C weighed by the weighing device 15a to the downstream junction 17. That is, the fixed-quantity supply unit 15 weighs the waste paper C by a predetermined mass using the weighing device 15a, and supplies the waste paper C to the downstream junction 17 using the supply mechanism.

[0017] The weighing device 15a may be a digital or analog weighing mechanism. Specifically, the weighing device 15a may be a physical sensor such as a load cell, a spring scale, or a balance. In this embodiment, a load cell is used as the weighing device 15a. The predetermined mass of the waste paper C weighed by the weighing device 15a is, for example, several grams to several tens of grams.

[0018] The feeding mechanism may be a known technique such as a vibration feeder, etc. The feeding mechanism may be included in the weighing device 15a.

[0019] The weighing and supply of the waste paper C in the quantitative supply unit 15 is a batch process. That is, the supply of the waste paper C from the quantitative supply unit 15 to the junction 17 is performed intermittently. The quantitative supply unit 15 may have a plurality of weighing devices 15a, and the weighing efficiency may be improved by operating the plurality of weighing devices 15a at staggered times.

[0020] At the junction 17, the waste paper C supplied from the quantitative supply unit 15 is joined and mixed with the fine pieces of the slit pieces S supplied from the shredding unit 86. The slit pieces S and the shredding unit 86 will be described later. The waste paper C mixed with the fine pieces flows from the junction 17 into the pipe 21.

[0021] The pipe 21 conveys the waste paper C from the first unit group 101 to the second unit group 102 by an air current generated by a blower (not shown).

[0022] The second unit group 102 has a defibrator 30, which is a dry type defibrator, a separation unit 40, piping 23, a mixing unit 91, and piping 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 has a collection unit 95, a compressor 97, a power supply unit 99, and piping 25 and air flow piping 29 connected to the separation unit 40.

[0023] The waste paper C transported through the pipe 21 flows into the defibrator 30. The defibrator 30 defibrates the waste paper C, which is a material containing fibers, in a dry manner to generate defibrated material containing fibers. A known defibration mechanism can be applied to the defibrator 30. In this embodiment, a defibration mechanism equipped with a rotary blade is used as the defibrator 30. The defibration mechanism shreds and defibrates the waste paper C with the rotary blade to generate fibers.

[0024] The waste paper C is defibrated by the defibrator 30, which untangles the tangled fibers contained in the waste paper C to form defibrated material containing fibers, and is transported to the separation section 40.

[0025] The separation unit 40 separates the defibrated fibers. More specifically, the separation unit 40 removes components contained in the fibers that are unnecessary for the production of the sheet P3. That is, the separation unit 40 separates relatively long fibers from relatively short fibers. Relatively short fibers may cause a decrease in the strength of the sheet P3, so they are selected and removed by the separation unit 40. The separation unit 40 also removes impurities such as coloring materials and additives contained in the waste paper C.

[0026] A known separation mechanism can be applied to the separation unit 40. In this embodiment, a disk-type separation mechanism equipped with a separation filter is used as the separation unit 40. The separation mechanism selects and separates relatively short fibers and impurities that pass through the separation filter from relatively long fibers that do not pass through the separation filter. The relatively long fibers are used as defibrated material for the material of the web W.

[0027] Humidified air is supplied to the inside of separation section 40 from second humidifier section 66 of third unit group 103.

[0028] From the defibrated fibers, relatively short fibers and the like are removed in the separation section 40. Then, the defibrated fibers are transported to the mixing section 91 via the pipe 23 by an airflow generated by a blower (not shown) arranged at the tip of the airflow pipe 29. Unnecessary parts such as relatively short fibers and impurities are discharged from the pipe 25 to the recovery section 95.

[0029] The mixer 91 mixes the defibrated material with a binder and the like in the air to produce a mixture. Although not shown, the mixer 91 includes a flow path through which the defibrated material is transported, a fan, a hopper, a supply pipe, and a valve.

[0030] The hopper communicates with the flow path of the defibrated material via a supply pipe. A 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. This adjusts the mixing ratio of the fibers and the binder.

[0031] The mixing section 91 may have a similar configuration for supplying a coloring material, an additive, and the like, in addition to the above-mentioned configuration for supplying the binder.

[0032] The fan of the mixer 91 generates an airflow to transport the defibrated material containing fibers downstream while mixing it with a binder and the like in the air to form a mixture. The mixture flows from the mixer 91 into the piping 24.

[0033] The collecting section 95 includes a filter (not shown) that filters out unnecessary materials such as relatively short fibers carried through the pipe 25 by the air current.

[0034] The compressor 97 generates compressed air. The filter may become clogged with fine particles of unwanted matter. The compressed air generated by the compressor 97 can be blown against the filter to blow away the particles adhering to the filter, thereby cleaning the filter.

[0035] The power supply unit 99 has a power supply device (not shown) that supplies power to the sheet manufacturing apparatus 1, and a control unit 5. The power supply unit 99 distributes power supplied from an external source to each component of the sheet manufacturing apparatus 1.

[0036] Although not shown, the control unit 5 includes a central processing unit (CPU) and a storage unit including a random access memory (RAM) and a read only memory (ROM). Various programs for controlling the sheet manufacturing apparatus 1 are stored in the storage unit. The control unit 5 may include dedicated hardware (application specific integrated circuit: ASIC) for executing at least some of the various processes. In other words, the control unit 5 may be configured as a circuit including one or more processors that operate according to a computer program (software), one or more dedicated hardware circuits such as ASIC, or a combination of these.

[0037] The processor includes a CPU and memory, such as RAM and ROM. The memory stores program codes or instructions configured to cause the CPU to execute processes. Memory, i.e., computer-readable media, includes anything that can be accessed by a general-purpose or special-purpose computer.

[0038] The control unit 5 is electrically connected to each component of the sheet manufacturing apparatus 1 including the second conveying unit 62, the air ejection unit 200, and the sheet forming unit 70, and controls the overall operation of these components. In particular, the control unit 5 also controls the folding of the web W, which will be described later.

[0039] The third unit group 103 deposits and compresses the mixture containing fibers, and forms it into a belt-shaped sheet P1, which is recycled paper. The third unit group 103 includes a depositing section 50, a first conveying section 61, a second conveying section 62, a first humidifying section 65, an air ejecting section 200, a second humidifying section 66, a draining section 68, and a sheet forming section 70. The second conveying section 62 is an example of a web conveying section of the present invention.

[0040] In the third unit group 103, the deposition unit 50, the first conveyor unit 61, the second conveyor unit 62, the first humidifier unit 65, and the sheet forming unit 70 are arranged in the above order from upstream to downstream. The air injection unit 200 is located inside the second conveyor unit 62 and is arranged at the downstream end of the conveying path of the web W in the second conveyor unit 62. The second humidifier unit 66 is arranged below the first humidifier unit 65.

[0041] The deposition unit 50 deposits the mixture generated from the defibrated material by airflow and gravity to form a web W. The deposition unit 50 has a drum member 53, a blade member 55 installed in the drum member 53, a housing 51 that accommodates the drum member 53, and a suction unit 59. The mixture is taken into the drum member 53 from the piping 24.

[0042] A first transport unit 61 is disposed below the deposition unit 50. The first transport unit 61 has a mesh belt 61a and five tension rollers (not shown) that tension the mesh belt 61a. The suction unit 59 faces the drum member 53 with the mesh belt 61a therebetween in the direction along the Z axis.

[0043] The blade member 55 is located inside the drum member 53 and is rotated by a motor (not shown). The drum member 53 is a semi-cylindrical sieve. A mesh functioning as a sieve is provided on the downward-facing side of the drum member 53. The drum member 53 allows particles such as fibers and mixtures that are smaller than the size of the mesh openings of the sieve to pass from the inside to the outside.

[0044] 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 is supplied from a second humidifying section 66 to the inside of the drum member 53.

[0045] The suction unit 59 is disposed below the drum member 53. The suction unit 59 sucks air inside the housing 51 through a plurality of holes in the mesh belt 61a. This generates an airflow that deposits the mixture on the mesh belt 61a. The plurality of holes in the mesh belt 61a allow air to pass through but prevent fibers and binders contained in the mixture from passing through. As a result, the mixture discharged to the outside of the drum member 53 is sucked downward together with the air. The suction unit 59 is a known suction device such as a suction fan.

[0046] The mixture is dispersed in the air within the housing 51 and is deposited on the upper surface of the mesh belt 61a by gravity and the air current generated by the suction section 59 to become the web W.

[0047] The mesh belt 61a is an endless belt that is stretched around five tension rollers. The mesh belt 61a rotates counterclockwise in FIG. 1 due to the rotation of the tension rollers. As a result, the mixture is continuously deposited on the mesh belt 61a, and a web W is formed. The web W contains a relatively large amount of air and is soft and inflated. The first conveying section 61 conveys the formed web W downstream by the rotation of the mesh belt 61a.

[0048] The second conveyor 62 is downstream of the first conveyor 61 and conveys the web W in place of the first conveyor 61. The second conveyor 62 peels the web W from the upper surface of the mesh belt 61a and conveys it toward the sheet forming unit 70. The second conveyor 62 is disposed above the conveying path of the web W and slightly upstream of the starting point of the return side of the mesh belt 61a. The +Y direction of the second conveyor 62 and the -Y direction of the mesh belt 61a partially overlap in the vertical direction.

[0049] The second conveying section 62 has a conveying belt 62a, four tension rollers (not shown), and a suction section 62b. The conveying belt 62a has a plurality of holes for passing air. The conveying belt 62a is stretched by the four tension rollers, and rotates clockwise in FIG. 1 by the rotation of the tension rollers.

[0050] The suction unit 62b is disposed above the conveyor belt 62a on the conveying path of the web W in the second conveyor 62. The suction unit 62b sucks the air below upward through a plurality of holes in the conveyor belt 62a. As a result, one side of the web W, which is the upper side, is adsorbed to the lower side of the conveyor belt 62a. When the conveyor belt 62a rotates in this state, the web W is adsorbed to the conveyor belt 62a and conveyed downstream. In other words, the conveyor belt 62a contacts one side of the web W to convey the web W. The suction unit 62b is a known suction device such as a suction fan.

[0051] The first humidifying section 65 humidifies the web W including fibers deposited in the depositing section 50 of the third unit group 103. In detail, the first humidifying section 65 is, for example, a mist type humidifier, and humidifies the web W transported by the second transport section 62 by supplying mist M from below. The first humidifying section 65 is disposed below the second transport section 62 and faces the web W transported by the second transport section 62 in the direction along the Z axis. A known humidifying device, for example, an ultrasonic type, can be used as the first humidifying section 65.

[0052] By humidifying the web W with the mist M, the function of the binder contained in the web W is promoted, and the strength of the sheet P3 is improved. In addition, since the web W is humidified from below, drops from the mist M are prevented from falling onto the web W. Furthermore, since the web W is humidified from the side opposite to the one side that contacts the conveyor belt 62a, the web W is less likely to stick to the conveyor belt 62a. The second conveyor 62 conveys the web W toward the sheet forming unit 70.

[0053] The air injection unit 200 is located in the second conveying unit 62, downstream of the suction unit 62b. Although not shown, the air injection unit 200 has a compressed air tank and an injection nozzle. The compressed air tank supplies compressed air to the injection nozzle. The air injection unit 200 injects compressed air downward from the injection nozzle toward the web W. Compressed air is supplied to and stored in the compressed air tank, for example, from a compressor (not shown) for the air injection unit 200.

[0054] The injection nozzle is a long and narrow opening extending in the direction along the X-axis. The injection nozzle faces the web W transported on the conveyor belt 62a in the direction along the Z-axis. The compressed air injected from the air injection unit 200 passes through the conveyor belt 62a and hits one side of the web W adsorbed to the lower surface of the conveyor belt 62a. At this time, since the length of the injection nozzle is longer than the length of the web W in the direction along the X-axis, the compressed air injected from the injection nozzle is sprayed across the entire width of the web W.

[0055] As a result, the web W is peeled off from the conveyor belt 62a. The compressed air is injected by the air injection unit 200 when the downstream leading end of the web W reaches the area facing the air injection unit 200. Then, after the leading end of the web W is peeled off from the conveyor belt 62a, the leading end of the web W is bent and folded. Thereafter, the web W is delivered from the second conveyor unit 62 to the sheet forming unit 70. The bending and folding of the web W will be described in detail later.

[0056] The sheet forming unit 70 has a first roller 71 and a second roller 72. The first roller 71 and the second roller 72 constitute a pressure roller pair 700. The sheet forming unit 70 pressurizes the web W between the first roller 71 and the second roller 72 to form a belt-shaped sheet P1 from the web W.

[0057] The first roller 71 and the second roller 72 form a pair, and each is a substantially cylindrical member. The rotation axis of the first roller 71 and the rotation axis of the second roller 72 are arranged along the X-axis. With respect to the transport path of the web W, the first roller 71 is arranged substantially above, and the second roller 72 is arranged substantially below. The first roller 71 and the second roller 72 rotate close to each other while the band-shaped sheet P1 is being formed from the web W, so that a load is applied to the web W.

[0058] In the direction along the X-axis, the length of the first roller 71 and the length of the second roller 72 are longer than the length of the web W, i.e., the width of the web W. Therefore, the web W is firmly sandwiched between the first roller 71 and the second roller 72.

[0059] The diameter of the first roller 71 is smaller than the diameter of the second roller 72. For example, the diameter of the first roller 71 is not less than 80 mm and not more than 110 mm, and the diameter of the second roller 72 is not less than 110 mm and not more than 150 mm.

[0060] The first roller 71 includes, for example, a core, an intermediate layer, and a surface layer. The core may be a hollow structure made of aluminum, iron, stainless steel, or the like. The intermediate layer covers the core and is also covered by the surface layer. In other words, the intermediate layer is interposed between the core and the surface layer.

[0061] Materials for the intermediate layer include elastomers such as silicone rubber and urethane rubber. The hardness of the elastomer is preferably 30 to 70, more preferably 40 to 60, as measured by an Asker C hardness tester. The thickness of the intermediate layer is preferably 1 mm to 10 mm, more preferably 1 mm to 5 mm.

[0062] Materials for the surface layer include fluororesins such as PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), and ETFE (tetrafluoroethylene-ethylene copolymer).

[0063] The first roller 71 having the above-mentioned configuration improves the releasability of the first roller 71 with respect to the web W. In addition, wear and damage to the intermediate layer is suppressed.

[0064] The second roller 72 includes, for example, a core metal and a surface layer covering the core metal. The core metal may be a hollow structure made of aluminum, iron, stainless steel, or the like. The surface layer may be made of fluororesins such as PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkylvinylether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), and ETFE (tetrafluoroethylene-ethylene copolymer), and silicone resin. This improves the releasability of the second roller 72 with respect to the web W. In addition, wear and damage to the core metal are suppressed.

[0065] The web W is pressurized by passing between the first roller 71 and the second roller 72. The pressure applied to the web W by the first roller 71 and the second roller 72 is preferably 0.1 MPa or more and 15.0 MPa or less, more preferably 0.2 MPa or more and 10.0 MPa or less, and even more preferably 0.4 MPa or more and 8.0 MPa or less. This suppresses deterioration of the fibers in the web W.

[0066] The second roller 72 has a built-in electric heater and is provided with a function of increasing the temperature of the roller surface. Similarly to the second roller 72, the first roller 71 is also preferably provided with a function of increasing the temperature of the roller surface by an electric heater.

[0067] The surface temperature of the second roller 72, i.e., the temperature of the surface layer of the second roller 72 in contact with the web W, is preferably 100° C. or higher and 130° C. or lower. The surface temperature of the first roller 71, i.e., the temperature of the surface layer of the first roller 71 in contact with the web W, is preferably 80° C. or higher and 100° C. or lower.

[0068] The second roller 72 has a relatively fine unevenness on its surface. The unevenness of the surface is indicated by the surface roughness measured by a surface roughness meter. The surface roughness of the surface of the second roller 72 is preferably 2 μm to 8 μm, more preferably 3 μm to 6 μm, in arithmetic mean roughness (Ra). Also, the maximum height (Rz) is preferably 15 μm to 70 μm, more preferably 25 μm to 50 μm. The unevenness of the surface of the second roller 72 may be due to the surface of the core metal, or may be due to the surface of the surface layer. These unevennesses are formed, for example, by blasting or thermal spraying.

[0069] Since the first roller 71 has an elastic intermediate layer as described above, when the web W is sandwiched between the first roller 71 and the second roller 72 and molded, the surface of the strip-shaped sheet P1 that comes into contact with the first roller 71 is likely to become uneven. On the other hand, if the surface of the second roller 72 is made smooth, the surface of the strip-shaped sheet P1 that comes into contact with the second roller 72 is likely to become smooth. In this case, a difference in surface quality, which is the difference in unevenness, is likely to occur between the front and back surfaces of the strip-shaped sheet P1. Such a difference in surface quality becomes a difference in smoothness between the front and back of the sheet P3, and when the sheet P3 is used as copy paper or the like, it may be necessary to use the front and back surfaces separately.

[0070] In contrast, the unevenness of the surface of the second roller 72 reduces the difference in surface quality between the front and back of the belt-like sheet P1, making it possible to use the front and back of the sheet P3 without distinguishing between them. In addition, in folding the web W, which will be described later, the ability of the web W to follow the second roller 72 is improved, making folding easier.

[0071] The second roller 72 is rotated by a drive motor described below. The first roller 71 is not driven by a motor or the like, but is a driven roller that rotates in conjunction with the rotation of the second roller 72. Therefore, the first roller 71 rotates in the opposite direction to the second roller 72 when viewed from the side in the -X direction.

[0072] The web W is sandwiched between the first roller 71 and the second roller 72 and sent downstream while being heated and pressurized. That is, the web W passes continuously through the sheet forming unit 70 and is press-formed while being heated. By using the first roller 71 and the second roller 72 as a pair of forming members, the web W is efficiently heated and pressurized.

[0073] The web W, which is soft and contains a relatively large amount of air, is reduced in air and its density increases as the web W passes through the sheet forming section 70. Then, the fibers are bound together by a binder, and the web W is formed into a belt-shaped sheet P1. The belt-shaped sheet P1 is transported to the first unit group 101 by a transport roller (not shown).

[0074] Here, the web W is formed by depositing the mixture, but in the initial stage of the formation of the web W, that is, in the region of the leading end of the web W, the thickness of the web W is not stable. In general, the thickness of the leading end of the web W tends to be thinner than the thickness of the rear part. When the thickness is thin, problems such as sticking to the first roller 71 or the second roller 72 and clogging of the sheet P1 in the conveying path may occur. In response to this, the sheet manufacturing apparatus 1 prevents the above problems from occurring by performing a folding operation described later at the leading end of the web W to double up and increase the thickness. In the following description, the leading end of the web W on the downstream side in the conveying direction may also be simply referred to as the leading end of the web W.

[0075] The second humidifier 66 is disposed below the first humidifier 65. A known evaporative humidifier can be used for the second humidifier 66. An example of an evaporative humidifier is one that blows air onto a moistened nonwoven fabric or the like to evaporate moisture and generate humidified air.

[0076] 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 separating section 40, and the inside of the drum member 53 of the stacking section 50. Specifically, humidified air is supplied to the above-mentioned area from the second humidifying section 66 through a plurality of pipes (not shown). In each of the above-mentioned configurations, the humidified air suppresses electrostatic charge on the waste paper C, fibers, etc., and suppresses adhesion of these materials to members due to static electricity.

[0077] The drainage unit 68 is a drainage tank. The drainage unit 68 is used in the first humidifying unit 65 and the second humidifying unit 66, etc., and collects and stores old moisture. The drainage unit 68 can be removed from the sheet manufacturing apparatus 1 as necessary, and the stored water can be discarded.

[0078] The strip-shaped sheet P1 transported to the first unit group 101 reaches the first cutting section 81. The first cutting section 81 cuts the strip-shaped sheet P1 in a direction intersecting the transport direction, for example, along the X-axis. The strip-shaped sheet P1 is cut into single sheets P2 at the first cutting section 81. The single sheets P2 are transported from the first cutting section 81 to the second cutting section 82.

[0079] The second cutting section 82 cuts the single-cut sheet P2 in the conveying direction, for example, in the direction along the Y axis. More specifically, the second cutting section 82 cuts both ends of the single-cut sheet P2 in the X axis direction. As a result, the single-cut sheet P2 becomes a sheet P3 of a predetermined shape, for example, A4 size or A3 size.

[0080] When the second cutting section 82 cuts the single-cut sheets P2 into sheets P3, slit pieces S, which are scraps, are generated. The slit pieces S are transported in the approximately -Y direction to reach the shredding section 86, which is a shredder. The shredding section 86 shreds the slit pieces S into small pieces and supplies them to the junction 17. A mechanism for weighing the small pieces of the slit pieces S and supplying them to the junction 17 may be provided between the shredding section 86 and the junction 17.

[0081] The sheet P3 is conveyed substantially upward and accumulated on the tray 84. In this manner, the sheet P3 is manufactured by the sheet manufacturing apparatus 1. The sheet P3 can be used as a substitute for, for example, copy paper.

[0082] 2. Web tip folding operation The bending and folding operation at the leading end of the web W will be described. As shown in Fig. 2, the folding operation of the web W in the sheet forming unit 70 has a first step S1, a second step S2, a third step S3, a fourth step S4, and a fifth step S5. These steps are executed in the above order under the control of the control unit 5. Each of the above steps will be described below with reference to Figs. 3 to 6. In the description of Figs. 3 to 6, a state viewed from the side from the -X direction will be described unless otherwise specified.

[0083] As shown in FIG. 3, in a first step S1, the second transport section 62 transports the web W downstream in the −Y direction.

[0084] In the normal forming operation in which the web W is passed between the first roller 71 and the second roller 72, the second roller 72 rotates in a counterclockwise rotation direction R1, and the first roller 71 rotates in a clockwise rotation direction R2. In the first step S1, the first roller 71 and the second roller 72 are rotated in the above-mentioned directions, respectively, as shown in FIG.

[0085] Then, when the leading edge of the web W passes the area facing the air injection unit 200, the process proceeds to the second step S2. Whether or not the leading edge of the web W has reached the area facing the air injection unit 200 can be determined by detecting the position of the leading edge of the web W using an optical sensor. Alternatively, a method can be applied in which the time from when the deposition unit 50 starts to drive until when the leading edge of the web W reaches the position facing the air injection unit 200 is test-measured in advance, and the timing control is performed by presetting the time.

[0086] 4, in the second step S2, the leading end of the web W is peeled off from the conveyor belt 62a. More specifically, in the second step S2, the leading end of the web W is peeled off from the conveyor belt 62a by the injection of compressed air from the air injection unit 200. During this time, the conveyor belt 62a continues to convey the web W, so that the leading end of the web W hangs down and comes into contact with the second roller 72.

[0087] 4, when the leading end of the web W comes into contact with the second roller 72, the second roller 72 may start to rotate in a clockwise rotation direction R2, which is the second direction. At that time, the first roller 71 rotates in a counterclockwise rotation direction R1 following the second roller 72.

[0088] In the second step S2, the leading end of the web W is peeled off from the conveyor belt 62a by the compressed air, and the leading end of the web W faces substantially downward. This makes it easier to bend the leading end of the web W in the subsequent third step S3. Then, the process proceeds to the third step S3.

[0089] 5, in a third step S3, the second roller 72 is rotated in a rotation direction R2, which is the second direction, with the leading end of the web W in contact with the surface of the second roller 72. As a result, the leading end of the web W is pulled by the surface of the second roller 72 and bent in the +Y direction (toward the lower right in the figure). At this time, the first roller 71 rotates in a counterclockwise rotation direction R1 following the second roller 72.

[0090] In a third step S3, the rotation of the second roller 72 in the rotation direction R2 is stopped after a predetermined time has elapsed. The distance by which the leading end of the web W is bent substantially in the +Y direction is adjusted by the diameter, rotation speed, and rotation time of the second roller 72. Then, the process proceeds to a fourth step S4.

[0091] 6, in the fourth step S4, the second roller 72 is rotated in a rotation direction R1, which is a first direction opposite to the second direction, and the first roller 71 is rotated in a rotation direction R2 accordingly. At the same time, the web W is passed between the pressure roller pair 700, which is the first roller 71 and the second roller 72. As a result, the leading end of the web W is pressurized and folded. Then, the process proceeds to the fifth step S5.

[0092] In the fifth step S5, following the fourth step S4, the second roller 72 continues to rotate in the rotation direction R1, and the first roller 71 continues to rotate in the rotation direction R2. As a result, the web W is pressed while passing between the pair of pressure rollers 700, and is heated by the first roller 71 and the second roller 72. As a result, a belt-shaped sheet P1 is continuously formed. The transport path of the belt-shaped sheet P1 is indicated by a dashed line in FIG. 6. Thereafter, the belt-shaped sheet P1 is transported toward the first cutting section 81 described above.

[0093] The folding distance at the downstream end of the belt-shaped sheet P1 in the conveying direction, i.e., the distance by which the web W is folded over, may be, for example, 20 mm or more in the conveying direction. The above distance is adjusted by the distance by which the leading end of the web W is folded in the third step S3.

[0094] The leading end of the web W is not limited to being folded twice. The third step S3 and the fourth step S4 described above may be repeated to fold the leading end of the web W three or more times. This further increases the thickness and strength of the leading end of the web W.

[0095] In the second step S2, the leading end of the web W may be curled and folded in a spiral shape by adjusting the transport speed of the web W after the leading end is peeled off and the rotation speed of the second roller 72. This increases the thickness of the leading end of the web W, further increasing the strength of the leading end of the web W.

[0096] 3.Sheet forming section The sheet forming unit 70 will be described in detail with respect to its configuration and its functions, including the folding of the web W and the separation and contact between the first roller 71 and the second roller 72.

[0097] 7 and 8, the sheet forming section 70 includes a first roller holding unit 711, a base unit 721, a first roller 71, a second roller 72, a gear set 76, a drive motor 79, a spring 794, and a pin 735. In addition, in Fig. 8, the first roller 71 and the second roller 72 arranged in the +X direction of the first roller holding unit 711 or the base unit 721 are shown by dashed lines.

[0098] The first roller 71 is installed in the first roller holding unit 711. As shown in Fig. 9, the first roller holding unit 711 has a substantially rectangular frame shape in a plan view from the +Z direction, and holds the first roller 71 inside. The first roller 71 is supported by the first roller holding unit 711 so as to be rotatable about a central axis (not shown) along the X-axis.

[0099] The first roller holding unit 711 is supported by the base unit 721 so as to be rotatable about an axis A1 as a rotation center when viewed from the side in the -X direction. In more detail, the axis A1 is aligned with the X axis and is located in approximately the +Y direction of the first roller 71 when viewed from the side in the -X direction. The first roller holding unit 711 is supported by the base unit 721 at a position where the axis A1 intersects with the side surface in the +X direction and the side surface in the -X direction.

[0100] The pins 735 are fixed to a +X side surface and a -X side surface of the first roller holding unit 711, respectively, to form a pair. One of the pair of pins 735 is provided so as to protrude in the +X direction from the +X side surface, and the other is provided so as to protrude in the -X direction from the -X side surface. When viewed through from the -X direction, the pair of pins 735 are positioned slightly below the first roller 71 in the -Y direction.

[0101] 7 and 8, base unit 721 supports first roller holding unit 711 in the +Z direction. Although not shown, base unit 721 is fixed to the frame of third unit group 103 described above via a subframe or the like. Drive motor 79 and gear group 76 are disposed on the -X direction side of the -X direction side of the base unit 721. Of the multiple gears in gear group 76, all except gear G1 are rotatably supported by base unit 721 or the like via members not shown.

[0102] In the base unit 721, a second roller 72 is disposed in the +Y direction. The second roller 72 is supported by the base unit 721 so as to be rotatable about a central axis (not shown) along the X axis. The second roller 72 is located in the -Z direction of the first roller 71 and slightly in the +Y direction.

[0103] Spring 794 is disposed on the -X side of the -X side surface of first roller retaining unit 711 and base unit 721, and on the +X side of the +X side surface (not shown).

[0104] Each of the pair of springs 794 is disposed so as to intersect with the X-axis and the Y-axis. One end of each spring 794 is fixed to an end of the first roller holding unit 711 in the -Y direction and +Z direction, and the other end of each spring 794 is fixed near the end of the base unit 721 in the -Y direction. As a result, the first roller holding unit 711 is biased in the counterclockwise direction on a circumference centered on the axis A1 when viewed from the side in the -X direction. This biasing force causes the first roller 71 to abut against the second roller 72.

[0105] The drive motor 79 is disposed approximately in the center along the Y axis of the base unit 721 and near the end in the -Z direction when viewed from a side in the -X direction. The drive motor 79 has an output shaft (not shown) that extends approximately along the Y axis. The output shaft protrudes in the +Y direction from the main body of the drive motor 79 along the Y axis. A gear G1 is directly connected to the output shaft. The drive motor 79 is rotatable in a counterclockwise forward direction and a clockwise reverse direction when viewed from the +Y direction.

[0106] The drive motor 79 is a drive source that executes, via the gear group 76, the rotation of the second roller 72, the contact and separation operation of the first roller 71 with respect to the second roller 72, and the above-mentioned folding operation of the leading end of the web W. As the drive motor 79, for example, a stepping motor or a known actuator can be used.

[0107] Gear group 76 includes multiple gears, gear G1 to gear G7. Gear group 76 is arranged from the +Y direction to the +Z direction of drive motor 79 in a side view from the -X direction. Gear group 76 is arranged in ascending order of numerical symbols from gear G1, the closest, to gear G7, the furthest, on a path through which the rotational drive force of drive motor 79 is transmitted.

[0108] Gear G1 is a worm gear, and is disposed in the +Y direction of drive motor 79. Gear G1 transmits the rotational driving force of drive motor 79 to gear G2.

[0109] Gear G2 is disposed on the -Z side of gear G1. The rotation axis (not shown) of gear G2 is aligned with the X-axis. Gear G2 transmits the rotational driving force transmitted from gear G1 to gear G3.

[0110] Gear G3 is disposed approximately in the +Y direction of gear G2. The rotation axis (not shown) of gear G3 is aligned with the X axis. Gear G3 transmits the rotational driving force transmitted from gear G2 to gear G4.

[0111] Gear G4 is disposed approximately in the +Y direction of gear G2. Gear G4 is an example of a second roller gear of the present invention, and is fixed to the end of second roller 72 in the -X direction. A rotation axis (not shown) of gear G4 is aligned with the X axis. Gear G4 receives the rotation of drive motor 79 transmitted from gear G2 to rotate second roller 72, and transmits the rotational driving force to first transmission gear G5a of gear G5.

[0112] The gear G5 includes a first transmission gear G5a and a one-way clutch gear G5b. The rotation of the gear G4 is transmitted to the first transmission gear G5a. As shown in Fig. 10, the first transmission gear G5a and the one-way clutch gear G5b are installed on the same rotation shaft A2.

[0113] The rotation shaft A2 is aligned along the X-axis. The one-way clutch gear G5b and the first transmission gear G5a are arranged in this order on the rotation shaft A2 in the +X direction. The rotation shaft A2 is rotatably supported by the base unit 721.

[0114] The first transmission gear G5a includes an idling mechanism that allows it to rotate idly for a certain period of time. The first transmission gear G5a transmits the rotation of the gear G4 to the rotation shaft A2 during the idling period. The idling mechanism will be described in detail later.

[0115] The one-way clutch gear G5b rotates in the first direction, i.e. counterclockwise, due to the rotation of the rotary shaft A2 in the first direction, and rotates freely relative to the rotation of the rotary shaft A2 in the second direction. The rotation of the one-way clutch gear G5b in the first direction is transmitted to gear G7, which serves as a cam gear, via gear G6.

[0116] Specifically, the rotation of the drive motor 79 is transmitted to the rotating shaft A2 via gear G4 and first transmission gear G5a, etc. When the drive motor 79 rotates in the reverse direction and the rotating shaft A2 rotates in the second direction, the one-way clutch gear G5b rotates idly. When the drive motor 79 rotates in the forward direction and the rotating shaft A2 rotates in the first direction, the one-way clutch gear G5b rotates and the rotational driving force is transmitted to gear G6.

[0117] The one-way clutch gear G5b may employ known techniques such as a cam type, a sprag type, or a planetary gear type.

[0118] 7 and 8, the gear G6 is disposed substantially in the -Y direction of the gear G5. The rotation axis (not shown) of the gear G6 is aligned with the X axis. The gear G6 transmits the rotational driving force transmitted from the one-way clutch gear G5b to the gear G7.

[0119] Gear G7 is disposed in the gear G6-Y direction. The rotation axis (not shown) of gear G7 is aligned with the X-axis. Rotation of one-way clutch gear G5b is transmitted to gear G7 via gear G6. As shown in FIG. 11, gear G7 is disposed on cam connecting shaft 771. Cam C17 is disposed in the +X direction of gear G7. Cam C17 is disposed coaxially with gear G7. That is, gear G7 and cam C17 are fixed to cam connecting shaft 771. Cam C17 can abut against pin 735 fixed in the -X direction of first roller holding unit 711.

[0120] The pin 735 positions the first roller holding unit 711 by abutting against the cam C17.

[0121] The cam connecting shaft 771 is aligned along the X-axis. Although not shown in the figure, a cam C17 is also fixed to the +X direction of the cam connecting shaft 771. In detail, the cam connecting shaft 771 extends in the +X direction, penetrating the -X direction side surface of the base unit 721. The +X direction end of the cam connecting shaft 771 penetrates the +X direction side surface of the base unit 721. A cam C17 is also fixed to the end. The cam C17 at the end can abut against a pin 735 fixed in the +X direction of the first roller holding unit 711.

[0122] Each cam C17 is an eccentric cam. The pair of cams C17 rotate in conjunction with the rotation of the gear G7 via the cam connecting shaft 771. As a result, each cam C17 repeatedly comes into contact with and separates from the corresponding pin 735 when the gear G7 rotates.

[0123] In this embodiment, the cam C17 fixed to the -X direction of the cam connecting shaft 771 is fixed to the gear G7. Note that the cam C17 does not necessarily have to be fixed to the gear G7.

[0124] 12, the first transmission gear G5a includes an idling mechanism 75. The idling mechanism 75 of the first transmission gear G5a includes a contact plate 751 and a pair of notches 752.

[0125] The pair of notches 752 causes the first transmission gear G5a to rotate idly relative to the rotation shaft A2. The pair of notches 752 are provided inside the first transmission gear G5a. The pair of notches 752 are arranged so as to overlap when rotated 180° about the rotation center of the rotation shaft A2. Each of the notches 752 is substantially fan-shaped when viewed from the side from the -X direction. When each of the notches 752 is considered to be fan-shaped, its central angle is 90°.

[0126] Here, in each cutout 752, the inner edge along the radial direction of the sector shape is defined as edge portions 752a and 752b. The first transmission gear G5a is not fixed to the rotating shaft A2 or the abutment plate 751. Therefore, the rotation of the first transmission gear G5a is transmitted to the rotating shaft A2 by the abutment of each edge portion 752a or each edge portion 752b with the abutment plate 751.

[0127] The contact plate 751 is plate-shaped, disposed inside the pair of notches 752, and fixed to the rotation shaft A2. When rotation is transmitted from the gear G4 to the first transmission gear G5a, the first transmission gear G5a rotates or rotates idle for a certain period of time depending on the positional relationship between the contact plate 751 and the edge portion 752a or edge portion 752b.

[0128] In the state shown in FIG. 12, when the first transmission gear G5a rotates in the second direction (clockwise), the edges 752b and the abutment plate 751 are in contact with each other, so the first transmission gear G5a does not rotate idly. That is, the rotation of the first transmission gear G5a is immediately transmitted to the rotation shaft A2. In contrast, when the first transmission gear G5a rotates in the second direction from a state in which the edges 752a and the abutment plate 751 are in contact with each other, the rotation shaft A2 rotates after a certain period of idling. That is, the abutment plate 751 moves relatively to the pair of notches 752, and the rotation of the first transmission gear G5a is not transmitted to the rotation shaft A2 until the abutment plate 751 and the edges 752b come into contact with each other.

[0129] 12, when the first transmission gear G5a rotates in the first direction (counterclockwise), the rotation shaft A2 rotates after a certain period of idling. That is, the abutment plate 751 moves relatively to the pair of notches 752, and the rotation of the first transmission gear G5a is not transmitted to the rotation shaft A2 until the abutment plate 751 and each edge portion 752a come into contact with each other. Then, when the first transmission gear G5a further rotates in the first direction and each edge portion 752a comes into contact with the abutment plate 751, the rotation of the first transmission gear G5a is transmitted to the rotation shaft A2.

[0130] In contrast, when the first transmission gear G5a rotates in the first direction from a state in which the edges 752a and the abutment plate 751 are in contact with each other, the rotation shaft A2 immediately rotates. In this embodiment, the certain period of time is set to coincide with the predetermined time during which the second roller 72 rotates in the rotation direction R2 in the third step S3.

[0131] In this manner, when the first transmission gear G5a rotates, the first transmission gear G5a rotates idly with respect to the rotating shaft A2 until the edges 752a, 752b of the cutout 752 come into contact with the abutment plate 751. Then, when the edges 752a, 752b of the cutout 752 come into contact with the abutment plate 751, the first transmission gear G5a rotates the rotating shaft A2.

[0132] More specifically, as shown in Fig. 13, when the gear G4 rotates in the first direction, that is, rotation direction R1, the first transmission gear G5a rotates in the second direction, that is, rotation direction R2. At this time, the first transmission gear G5a rotates idly for a certain period of time until the edges 752b and the abutment plate 751 abut against each other, and then the rotation shaft A2 rotates in the rotation direction R2. In Fig. 13, since the edges 752b and the abutment plate 751 abut against each other, the first transmission gear G5a rotates the rotation shaft A2 in the rotation direction R2 without rotating idly.

[0133] 14, when the gear G4 rotates in the second direction, that is, rotation direction R2, the first transmission gear G5a rotates in the first direction, that is, rotation direction R1. At this time, the first transmission gear G5a rotates idly for a certain period of time until the edges 752a and the abutment plate 751 abut against each other, and then the rotation shaft A2 rotates in the rotation direction R1. In FIG. 14, the edges 752a and the abutment plate 751 abut against each other, so the first transmission gear G5a rotates the rotation shaft A2 in the rotation direction R1 without rotating idly.

[0134] Various operations of the sheet forming unit 70 via the drive motor 79 and the gear group 76 will be described below. In the following description, unless otherwise specified, a state viewed from the side from the -X direction will be described. Note that, for convenience of illustration, configurations other than the cam C17, gear G7, pin 735, shaft A1, first roller holding unit 711, base unit 721, first roller 71, and second roller 72 are omitted in Figures 15, 17, 20, and 22.

[0135] When the sheet manufacturing apparatus 1 is operated, the sheet forming unit 70 performs an operation preparation operation. More specifically, when the sheet manufacturing apparatus 1 is at rest, the first roller 71 is separated from the second roller 72 as shown in FIG. 15. Specifically, the pin 735 abuts against and rides on the cam C17. Therefore, the -Y direction of the first roller holding unit 711 is raised upward with the axis A1 as a fulcrum relative to the base unit 721. As a result, the first roller 71 is slightly separated from the second roller 72. At this time, the gap between the surface of the first roller 71 and the surface of the second roller 72 is, for example, about 2 to 5 mm. The position of the first roller holding unit 711 is fixed by the pin abutting against a recess in the upper part of the cam C17.

[0136] From the above-mentioned state, an operation preparation operation is performed to bring the first roller 71 into contact with the second roller 72. First, as shown in Fig. 16, the drive motor 79 is rotated in the forward direction (counterclockwise) to rotate the gear G4 in the second direction (clockwise). This causes the one-way clutch gear G5b to rotate in the first direction (counterclockwise), and the gear G7 also rotates in the first direction via the gear G6.

[0137] 17, the cam C17 also rotates in the first direction in conjunction with the rotation of the gear G7. The rotation of the cam C17 separates the cam C17 from the pin 735. When the cam and the pin are separated, the gap between the cam and the pin may be about 2 mm. The first roller holding unit 711 is then lowered with the axis A1 as a fulcrum by the bias of the spring 794. This causes the first roller 71 to move substantially downward, and the first roller 71 and the second roller 72 come into contact with each other. By operating the sheet manufacturing apparatus 1 in this state, the web W described above is pressed by the first roller 71 and the second roller 72.

[0138] In this way, the cam C17 rotates a predetermined angle in conjunction with the rotation of the gear G7, thereby raising or lowering the first roller holding unit 711 via the pin 735. The predetermined angle is 180° in this embodiment, but may be set to another angle. The contact and separation between the cam C17 and the pin 735 are linked on the +X direction side and the -X direction side of the sheet forming section 70. Furthermore, if the rotation angle of the cam C17 is detected by a position sensor, the contact and separation between the first roller 71 and the second roller 72 can be more accurately determined.

[0139] Next, when forming the belt-shaped sheet P1, first, the above-mentioned folding of the leading edge of the web W is performed. In the folding operation of the leading edge of the web W, as shown in FIG. 18, the driving motor 79 is rotated in the forward direction to rotate the gear G4 in the second direction. At this time, the rotation of the driving motor 79 in the forward direction is set to be less than a certain period during which the first transmission gear G5a rotates idly. As a result, although the first transmission gear G5a is rotated by the gear G4, the above-mentioned idling mechanism 75 causes the first transmission gear G5a to rotate idly with respect to the above-mentioned rotation shaft A2 for a certain period, so that the rotational driving force is not transmitted beyond the rotation shaft A2. Therefore, the cam C17 does not rotate, and the first roller holding unit 711 does not move. On the other hand, the gear G4 rotates in the second direction, so that the second roller 72 rotates in the second direction, and the leading edge of the web W is folded by the above-mentioned mechanism.

[0140] Next, folding is performed on the leading end of the bent web W. The folding operation is similar to the forming operation of the strip-shaped sheet P1, and the forming operation of the sheet P1 is performed following the folding operation.

[0141] In the folding operation of the leading end of the web W, as shown in Fig. 19, the driving motor 79 is rotated in the reverse direction (clockwise) to rotate the gear G4 in the first direction. At this time, the first transmission gear G5a is rotated by the gear G4 to rotate the rotation shaft A2 in the second direction, but the rotation shaft A2 rotates idly relative to the one-way clutch gear G5b. Therefore, the rotational driving force is not transmitted beyond the one-way clutch gear G5b. Therefore, the cam C17 does not rotate, and the first roller holding unit 711 does not move.

[0142] On the other hand, because the gear G4 rotates in the first direction, the second roller 72 rotates in the first direction and the first roller 71 rotates in the second direction. As a result, the leading end of the folded web W passes between the first roller 71 and the second roller 72, and the leading end is folded. Furthermore, by continuing to rotate the drive motor 79 in the reverse direction, the area following the leading end of the web W is pressurized to form a strip-shaped sheet P1.

[0143] When the sheet manufacturing apparatus 1 is paused, a pre-pause operation is performed in the sheet forming unit 70. More specifically, when the sheet manufacturing apparatus 1 is in operation, the first roller 71 is brought into contact with the second roller 72 as shown in FIG. 20. Specifically, the cam C17 and the pin 735 are separated from each other. As a result, the -Y direction of the first roller holding unit 711 is lowered with the axis A1 as a fulcrum, and the first roller 71 and the second roller 72 are in contact with each other. From this state, a pre-pause operation is performed to separate the first roller 71 from the second roller 72.

[0144] First, as shown in Fig. 21, the drive motor 79 is rotated in the forward direction to rotate the gear G4 in the second direction. At this time, the gear G4 continues to rotate beyond the idling period of the first transmission gear G5a, so that the rotation of the first transmission gear G5a is transmitted to the rotation shaft A2. As a result, the one-way clutch gear G5b rotates in the first direction, and the gear G7 also rotates in the first direction via the gear G6.

[0145] 22, the cam C17 also rotates in the first direction in conjunction with the rotation of the gear G7. The rotation of the cam C17 causes the pin 735 to come into contact with and ride up on the cam C17. As a result, the -Y direction of the first roller holding unit 711 rises with the axis A1 as a fulcrum relative to the base unit 721 against the bias of the spring 794. As a result, the first roller 71 also moves substantially upward, and the first roller 71 and the second roller 72 are separated from each other. In this state, the sheet manufacturing apparatus 1 is stopped.

[0146] According to this embodiment, the following effects can be obtained.

[0147] In the deposition section 50, even if the leading end of the web W becomes thin in the initial stage of forming the web W, defects that may occur as a result can be prevented. More specifically, since the leading end of the web W is folded, the web W is overlapped twice at the leading end of the web W. Therefore, even if the leading end of the web W before folding is thin, the thickness and strength of the web W that are unlikely to cause defects are ensured.

[0148] In addition, the above-mentioned operations are realized with a small number of parts, and the device is also compact. More specifically, the forward rotation of the drive motor 79 bends the leading end of the web W. Next, the forward rotation of the drive motor 79 is switched to the reverse rotation before a certain period of time during which the idling mechanism 75 rotates idly is exceeded. Then, the leading end of the folded web W passes between the first roller 71 and the second roller 72 and is folded, and then the area following the leading end of the web W is pressed to form a strip-shaped sheet P1. In this way, the folding operation of the leading end of the web W and the operation of forming the strip-shaped sheet P1 from the web W are performed by a single drive motor 79. At this time, the reverse rotation of the drive motor 79 is not transmitted to the gear G7, which is a cam gear, due to the idling of the one-way clutch gear G5b.

[0149] Furthermore, when the rotation of the drive motor 79 in the forward direction continues beyond a certain period during which the idling mechanism 75 rotates, the gear G7 rotates via the one-way clutch gear G5b, and the cam C17 and the pin 735 come into contact with each other. Then, when the cam C17 moves the first roller holding unit 711 together with the pin 735 upward, the first roller 71 separates from the second roller 72. If the above operation is performed, for example, before the sheet manufacturing apparatus 1 is paused, the first roller 71 and the second roller 72 separate from each other during the pause, and deformation and wear of each roller are suppressed. And, since the drive motor 79 is used to separate the first roller 71 and the second roller 72, no drive mechanism other than the drive motor 79 is required, and an increase in the number of parts can be suppressed. As a result, even if the leading end of the web W is thin, the occurrence of defects can be prevented, and the sheet manufacturing apparatus 1 can be made compact. [Explanation of symbols]

[0150] Reference Signs List 1...sheet manufacturing apparatus, 30...defibrator, 50...stacking section, 62...second conveying section as web conveying section, 62a...conveyor belt, 70...sheet forming section, 71...first roller, 72...second roller, 75...idling mechanism, 79...drive motor, 711...first roller holding unit, 735...pin, C17...cam, 751...contact plate, 752...notch, 752a, 752b...edge, A2...rotating shaft, G4...gear as gear for second roller, G5a...first transmission gear, G5b...one-way clutch gear, G7...gear as gear for cam, W...web.

Claims

1. A defibrator that defibrates a fiber-containing material to generate a defibrated material; a depositing section for depositing the defibrated material to form a web; a sheet forming section having a first roller and a second roller and pressing the web to form a sheet; The sheet forming unit includes: a first roller holding unit in which the first roller is installed; A drive motor capable of rotating in both forward and reverse directions; a second roller gear to which rotation of the drive motor is transmitted to rotate the second roller; a first transmission gear to which rotation of the second roller gear is transmitted; a one-way clutch gear mounted on the same rotary shaft as the first transmission gear; a cam gear to which the rotation of the one-way clutch gear is transmitted; A cam that is installed coaxially with the cam gear; a pin that is fixed to the first roller holding unit and abuts against the cam to position the first roller holding unit, The first transmission gear is provided with an idling mechanism that is capable of idling for a certain period of time.

2. The idling mechanism of the first transmission gear includes: A notch provided in the first transmission gear; The sheet manufacturing apparatus according to claim 1 , further comprising: a contact plate fixed to the rotating shaft in correspondence with the notch.

3. The first transmission gear rotates freely relative to the rotary shaft until the edge of the notch and the abutment plate come into contact with each other. The sheet manufacturing apparatus according to claim 2 , wherein the edge of the notch and the abutment plate are in contact with each other, and the first transmission gear rotates the rotation shaft.

4. When the rotation of the drive motor in the reverse direction is transmitted to the rotating shaft via the second roller gear and the rotating shaft rotates in a second direction, the one-way clutch gear rotates idle, 2. The sheet manufacturing apparatus according to claim 1, wherein the one-way clutch gear rotates when the forward rotation of the drive motor is transmitted to the rotating shaft and the rotating shaft rotates in a first direction opposite to the second direction.

5. The sheet manufacturing apparatus according to claim 1 , wherein the cam rotates through a predetermined angle to raise or lower the first roller holding unit via the pin.

6. The sheet manufacturing apparatus according to claim 5 , wherein the first roller holding unit is lowered so that the first roller and the second roller come into contact with each other, and the web is pressed by the first roller and the second roller.

7. The sheet manufacturing apparatus according to claim 6 , wherein the cam is an eccentric cam.

8. The sheet manufacturing apparatus according to claim 7 , wherein the cam is fixed to the cam gear.

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