Patent Application
20240360623
The present application is based on, and claims priority from JP Application Serial Number 2023-073106, filed Apr. 27, 2023, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present disclosure relates to a sheet separating apparatus and a sheet manufacturing apparatus.
Japanese Patent No. 6311749 discloses a configuration of a sheet manufacturing apparatus that causes a web, that is, a sheet such as copy paper to pass between a pair of heating and pressing rollers so as to perform heating and pressing on the sheet that is transported.
JP-A-2009-92987 discloses a configuration of an image forming apparatus that pinches a sheet with a heating roller and a pressing roller around which a fixing belt is wound and rotates the rollers so as to transport the sheet downstream. A separating member for separating a sheet adhering to the fixing belt is disposed near the fixing belt.
However, in the configuration described in Japanese Patent No. 6311749, there is a problem in which when a sheet adheres to the heating and pressing rollers, the sheet cannot be separated since a member for separating the sheet is not disposed, and the sheet cannot be transported downstream. In addition, in the configuration described in JP-A-2009-92987, there is a problem in which although a separating member is disposed, a leading end of the separating member is bent due to thermal expansion when heat is applied to the separating member, and the sheet cannot be separated appropriately from the heating roller or the pressing roller.
A sheet separating apparatus includes a pair of rollers that transports a sheet while heating the sheet, and a separating unit that includes a separating plate and a supporting portion. The separating plate has a leading end portion that comes into contact with one roller of the pair of rollers. The supporting portion supports the separating plate. The separating plate is provided with a slit that absorbs bending due to a thermal expansion difference between the separating plate and the supporting portion.
A sheet manufacturing apparatus includes a supply unit that supplies a raw material, a deposition unit that accumulates a part of the raw material and forms a sheet, a pressing unit that presses the sheet, and a cutting unit that cuts the sheet. The pressing unit includes a pair of rollers that transports the sheet while heating the sheet, and a separating unit that includes a separating plate and a supporting portion. The separating plate has a leading end portion that comes into contact with one roller of the pair of rollers. The supporting portion supports the separating plate. The separating plate is provided with a slit that absorbs bending due to a thermal expansion difference between the separating plate and the supporting portion.
Hereinafter, in each figure, description will be given assuming that three axes orthogonal to each other are an X axis, a Y axis, and a Z axis. In addition, a direction extending along the X axis is referred to as an X direction, a direction extending along the Y axis is referred to as a Y direction, and a direction extending along the Z axis is referred to as a Z direction, and an arrow pointing direction is referred to as a positive direction, and an opposite direction of the positive direction is referred to as a negative direction. Note that a +Z direction may be referred to as up, upward, or a front side, and a −Z direction may be referred to as down, downward, or a rear side, and viewing in the +Z direction or the −Z direction is also referred to as plan view or in plan view. In addition, description will be given assuming that a surface on a positive side in the Z direction is an upper surface or a front surface, and a surface on a negative side in the Z direction, which is the opposite side of the surface on the positive side in the Z direction, is a lower surface or a rear surface.
First, with reference to
As illustrated in
The sheet manufacturing apparatus 1000 includes a supply unit 10, a crushing unit 12, a defibrating unit 20, a screening unit 40, a first web forming unit 45, a rotary body 49, a mixing unit 50, a deposition unit 60, a second web forming unit 70, a transport unit 78, a moisture applying unit 79, a pressing unit 80, and a cutting unit 90.
The supply unit 10 supplies a raw material to the crushing unit 12. The supply unit 10 is, for example, an automatic feeding unit for continuously feeding the raw material to the crushing unit 12. The raw material supplied by the supply unit 10 is a material containing various types of fibers.
The fibers are not particularly limited, and a wide range of fiber materials can be used. Examples of the fibers include natural fibers (animal fibers and plant fibers), and chemical fibers (organic fibers, inorganic fibers, and organic-inorganic composite fibers). More specifically, examples include fibers made from cellulose, silk, wool, cotton, hemp, ambary hemp, flax, ramie, jute, Manila hemp, sisal hemp, conifer, and broadleaf tree, and these fibers may be used independently, used by being appropriately mixed, or used as recycled fibers that have been refined.
Examples of the raw material of the fibers include pulp, used paper, and used cloth. In addition, various surface treatments may be performed on the fibers. In addition, the material of the fibers may be a pure material, or may be a material containing a plurality of components such as impurities and other components. In addition, a defibrated material obtained through defibration of used paper or a pulp sheet by using a dry method may be used as the fibers.
The crushing unit 12 cuts the raw material supplied by the supply unit 10 into small pieces in air such as in the atmosphere. The shape or the size of the small pieces is, for example, several centimeters square. In the example of
The defibrating unit 20 defibrates the raw material cut by the crushing unit 12. Here, the term “defibrate” refers to untangling, into individual fibers, the raw material in which a plurality of fibers is bonded. The defibrating unit 20 also has a function of separating, from the fibers, substances such as resin particles, ink, toner, or a blur preventing agent that are attached to the raw material.
The material that has passed through the defibrating unit 20 is referred to as a “defibrated material”. In addition to the untangled defibrated material fibers, the “defibrated material” may also contain resin particles, colorants such as ink and toner, and additives such as blur preventing agents and paper strengthening agents that are separated from the fibers when the fibers are untangled. The shape of the untangled defibrated material is string-like. The untangled defibrated material may be present in a state of not being entangled with other untangled fibers, that is, in an independent state, or may be present in a state of being entangled with other untangled defibrated materials to form a clump, that is, in a state of forming a so-called “lump”.
The defibrating unit 20 performs defibration by using a dry method. Here, performing a treatment of defibration or the like in air such as in the atmosphere is referred to as a dry method. For example, an impeller mill is used as the defibrating unit 20. The defibrating unit 20 has the function of causing an airflow to be generated so as to suck the raw material and discharge the defibrated material. As a result, the defibrating unit 20 can suck the raw material with the airflow from an inlet 22 and perform the defibration treatment, and transport the defibrated material to an outlet 24 by using the airflow generated by the defibrating unit 20. The defibrated material that has passed through the defibrating unit 20 is transferred to the screening unit 40 via a pipe 3. Note that the airflow for transporting the defibrated material from the defibrating unit 20 to the screening unit 40 may be the airflow generated by the defibrating unit 20 or an airflow of an airflow generating device provided as a blower or the like.
The screening unit 40 receives the defibrated material defibrated by the defibrating unit 20 from an inlet 42 and screens the defibrated material according to fiber length. The screening unit 40 includes, for example, a drum unit 41 and a housing unit 43 that houses the drum unit 41. A sieve, for example, is used as the drum unit 41. The drum unit 41 includes a mesh and can separate a first screened material from a second screened material. The first screened material is a material passing through the mesh and including fibers or particles that are smaller than the size of the openings of the mesh. The second screened material is a material not passing through the mesh and including fibers, non-defibrated pieces, or lumps that are larger than the size of the openings of the mesh. For example, the first screened material is transferred to the deposition unit 60 via a pipe 7, and the second screened material is returned to the defibrating unit 20 from an outlet 44 via a pipe 8. Specifically, the drum unit 41 is a cylindrical sieve that is driven and rotated by a motor. For example, a metal mesh, expanded metal in which a perforated metal plate is expanded, or punched metal in which holes are formed in a metal plate by a pressing machine or the like is used as the mesh of the drum unit 41.
The first web forming unit 45 transports the first screened material that has passed through the screening unit 40 to the pipe 7. The first web forming unit 45 includes, for example, a mesh belt 46, a tensioned roller 47, and a suction mechanism 48.
The suction mechanism 48 can suck the first screened material that is dispersed in air after passing through the opening of the screening unit 40 onto the mesh belt 46. The first screened material is deposited on the moving mesh belt 46 and forms a web V.
A passing-through material that has passed through the opening of the screening unit 40 is deposited on the mesh belt 46. The mesh belt 46 is tensioned by the tensioned roller 47 and is configured not to allow the passing-through material to easily pass through and to allow air to pass through the mesh belt 46. The mesh belt 46 moves by rotation of the tensioned roller 47. The web V is formed on the mesh belt 46 by the passing-through material that has passed through the screening unit 40 continuously accumulating while the mesh belt 46 continuously moves.
The suction mechanism 48 is provided below the mesh belt 46. The suction mechanism 48 can generate a downward airflow. The passing-through material dispersed in air by the screening unit 40 can be sucked onto the mesh belt 46 by the suction mechanism 48. As a result, the discharge speed from the screening unit 40 can be increased.
The web V is formed to have a large volume of air and softly swelled by passing through the screening unit 40 and the first web forming unit 45. The web V deposited on the mesh belt 46 is fed to the pipe 7 and transported to the deposition unit 60.
The rotary body 49 can cut the web V. In the example of
The mixing unit 50 mixes, for example, the first screened material that has passed through the screening unit 40 and a bonding agent. The mixing unit 50 includes, for example, a bonding agent supply unit 52 that supplies the bonding agent, a pipe 54 that transports the first screened material and the bonding agent, and a blower 56. In the example of
The blower 56 generates an airflow in the mixing unit 50, and the first screened material and the bonding agent can be transported while being mixed in the pipe 54. Note that the mechanism that mixes the first screened material and the bonding agent is not particularly limited, and may be a mechanism that agitates the first screened material and the bonding agent by using blades that rotate at high speed, or may be a mechanism, such as a V-type mixer, that uses the rotation of a container.
A screw feeder, a disk feeder, or the like is used as the bonding agent supply unit 52. The bonding agent supplied from the bonding agent supply unit 52 is, for example, starch or dextrin. Starch is a polymer in which a plurality of a-glucose molecules is polymerized through glucoside bonds. Starch may exist in the form of straight chains or may branch.
Note that the bonding agent supply unit 52 may supply, in addition to the bonding agent, coloring agents for coloring the fibers, coagulation inhibitors for inhibiting aggregation of the fibers or aggregation of the bonding agent, and flame retardants for making the fibers and the like more difficult to burn, according to the type of a fiber body S to be manufactured. A mixture that has passed through the mixing unit 50 is transferred to the deposition unit 60 via the pipe 54.
The deposition unit 60 receives, from an inlet 62, the mixture that has passed through the mixing unit 50, unravels the entangled defibrated material, and causes the defibrated material to descend while dispersing the defibrated material in air. As a result, the deposition unit 60 can uniformly deposit the mixture on the second web forming unit 70.
The deposition unit 60 includes, for example, a drum unit 61 and a housing unit 63 that houses the drum unit 61. A cylindrical sieve that rotates is used as the drum unit 61. The drum unit 61 includes a mesh and causes fibers or particles included in the mixture that has passed through the mixing unit 50 and smaller than the size of the openings of the mesh to descend. The configuration of the drum unit 61 is, for example, the same as the configuration of the drum unit 41.
Note that the “sieve” of the drum unit 61 does not have to have a function of screening specified target materials. That is, the term “sieve” used as the drum unit 61 means a sieve provided with a mesh, and the drum unit 61 may cause all of the mixture introduced into the drum unit 61 to descend.
The second web forming unit 70 accumulates the passing-through material that has passed through the deposition unit 60 and forms a web W. The second web forming unit 70 includes, for example, a first mesh belt 72 as a first transport belt, a tensioned roller 74, and a suction mechanism 76.
The passing-through material that has passed through the openings of the deposition unit 60 is deposited on the first mesh belt 72. The first mesh belt 72 is tensioned by the tensioned roller 74 and is configured not to allow the passing-through material to easily pass through and to allow air to pass through the first mesh belt 72. The first mesh belt 72 moves by rotation of the tensioned roller 74. The web W is formed on the first mesh belt 72 by the passing-through material that has passed through the deposition unit 60 continuously accumulating while the first mesh belt 72 continuously moves.
The suction mechanism 76 is provided below the first mesh belt 72. The suction mechanism 76 can generate a downward airflow. The mixture dispersed in air by the deposition unit 60 can be sucked onto the first mesh belt 72 by the suction mechanism 76. As a result, the discharge speed from the deposition unit 60 can be increased. Moreover, a down flow can be formed by the suction mechanism 76 in a dropping path of the mixture, and the defibrated material and the bonding agent can be prevented from being entangled while the mixture is dropping.
As described above, the web W is formed to have a large volume of air and softly swelled by passing through the deposition unit 60 and the second web forming unit 70.
The transport unit 78 is disposed downstream on the first mesh belt 72 in the transport direction of the web W. The transport unit 78 separates the web W on the first mesh belt 72 from the first mesh belt 72 and transports the web W toward the pressing unit 80. The transport unit 78 includes a second mesh belt 78a as a second transport belt, a roller 78b, and a suction mechanism 78c. The second mesh belt 78a is tensioned by the roller 78b and is configured to allow air to pass through the second mesh belt 78a. The second mesh belt 78a is configured to move by rotation of the roller 78b. The suction mechanism 78c is disposed at a position facing the web W with the second mesh belt 78a interposed therebetween. The suction mechanism 78c includes a blower and generates an upward airflow on the second mesh belt 78a by the suction power of the blower. The web W is sucked by the airflow.
As a result, one surface of the web W is separated from the first mesh belt 72, and another surface, which is an opposite surface from the surface that is separated from the first mesh belt 72, can be sucked onto the second mesh belt 78a. The web W sucked onto the second mesh belt 78a is transported in a state of being in contact with the second mesh belt 78a.
The moisture applying unit 79 is disposed below the transport unit 78. The moisture applying unit 79 applies moisture toward a first surface of the web W in contact with the second mesh belt 78a. The moisture applying unit 79 applies, for example, water vapor or mist as moisture to the web W. As a result, moisture can be uniformly applied to the web W.
The pressing unit 80 is disposed downstream of the transport unit 78 and the moisture applying unit 79. The web W to which moisture is applied is transported to the pressing unit 80.
The pressing unit 80 presses the web W to which moisture is applied and that is separated from the second mesh belt 78a. The pressing unit 80 of the present embodiment simultaneously performs pressing and heating on the web W to which moisture is applied. As a result, the moisture contained in the web W evaporates after the temperature rises, and at the same time, the web W becomes thinner and the fiber density is increased. When the temperatures of the moisture and the bonding agent rise by heat and the fiber density is increased by pressure, the bonding agent is gelatinized. Thereafter, a plurality of fibers is bonded via the bonding agent that is gelatinized by the moisture evaporation. Moreover, when the moisture evaporates by heat and the fiber density is increased by pressure, a plurality of fibers is bonded by hydrogen bonds. As a result, the sheet-like fiber body S having higher mechanical strength can be formed.
The pressing unit 80 of the present embodiment includes a pressing and heating unit 84 that presses and heats the web W. The pressing and heating unit 84 is configured using, for example, a heating roller and a heat press-molding machine. In the example of
A separating unit 100 that separates the web W, that is, the sheet-like fiber body S adhering to the roller 86b from the roller 86b is disposed near the roller 86b of the pair of rollers 86a and 86b.
The cutting unit 90 cuts the fiber body S formed by the pressing unit 80. In the example of
Next, with reference to
As illustrated in
The separating unit 100 includes a separating plate 200 having a leading end portion 201 that comes into contact with the second roller 86b, and a supporting portion 300 that supports the separating plate 200. When the leading end portion 201 of the separating plate 200 comes into contact with a surface of the second roller 86b, a leading end of the sheet S transported, that is, a leading end of the sheet S adhering to the second roller 86b can be separated from the second roller 86b.
Three press rollers 410, 420, and 430 are in contact with the surface of the second roller 86b. As a result, the transported sheet S can be transported in a direction toward the separating unit 100. In addition, a wind-around roller 450 for transporting the sheet S downstream is disposed near the separating unit 100. That is, the sheet S that has passed between the rollers 86a and 86b passes between the separating unit 100 and the wind-around roller 450 and is transported downstream.
As illustrated in
As illustrated in
Next, with reference to
As illustrated in
As illustrated in
The material of the separating plate 200 is preferably flexible and heat-resistant, and is, for example, polyimide. Since the separating plate 200 is made of polyimide, the separating plate 200 is highly heat-resistant, and in addition, is less likely to damage the second roller 86b when coming into contact with the second roller 86b.
Examples of the material of the supporting portion 300 include steel electrolytic cold commercial (SECC) or stainless steel. As described above, the supporting portion 300 and the separating plate 200 have different thermal expansion coefficients. Specifically, the supporting portion 300 is less likely to expand with heat, and the separating plate 200 easily shrinks.
However, since the plurality of slits 210 is formed in the separating plate 200, bending of the separating plate 200 due to the thermal expansion difference between the separating plate 200 and the supporting portion 300 can be absorbed. That is, compared to a case where the separating plate 200 is provided with no slit 210, the separating plate 200 provided with the slits 210 can mitigate expansion and contraction.
As described above, even when heat is transmitted to the separating plate 200 and the supporting portion 300, since the separating plate 200 is provided with the slits 210, bending due to the thermal expansion difference between the separating plate 200 and the supporting portion 300 can be absorbed by the slits 210. Therefore, bending of the leading end portion 201, in the separating plate 200, that comes into contact with the sheet S, in other words, occurrence of warping can be suppressed. As a result, the leading end portion 201 of the separating plate 200 can come into contact with the second roller 86b without a gap, and the sheet S adhering to the second roller 86b can be separated from the second roller 86b. As a result, the sheet S can be reliably transported downstream.
Next, with reference to
As illustrated in
As described above, since the separating unit 100 is disposed so as to be able to come into contact with or be separated from the second roller 86b, when the sheet S adhering to the second roller 86b is separated, the separating unit 100 comes into contact with the surface of the second roller 86b, and after the sheet S is separated, the separating unit 100 is caused to be in non-contact, that is, the separating unit 100 is separated from the second roller 86b. As a result, damage to the surface of the second roller 86b and deterioration of the surface can be suppressed.
As described above, the sheet separating apparatus 100A of the present embodiment includes the rollers 86a and 86b that transport the sheet S while heating the sheet S, and the separating unit 100 that includes the separating plate 200 having the leading end portion 201 that comes into contact with the second roller 86b of the rollers 86a and 86b, and the supporting portion 300 that supports the separating plate 200. The separating plate 200 is provided with the slits 210 that absorb bending due to a thermal expansion difference between the separating plate 200 and the supporting portion 300.
According to this configuration, even when the sheet S is heated and the heat is transmitted to the separating plate 200 and the supporting portion 300, since the separating plate 200 is provided with the slits 210, bending due to the thermal expansion difference between the separating plate 200 and the supporting portion 300 can be absorbed by the slits 210. Therefore, bending of the leading end portion 201, in the separating plate 200, that comes into contact with the sheet S, in other words, occurrence of warping can be suppressed. As a result, the leading end portion 201 of the separating plate 200 can come into contact with the second roller 86b without a gap, and the sheet S adhering to the second roller 86b can be separated from the second roller 86b. As a result, the sheet S can be reliably transported downstream.
In addition, in the sheet separating apparatus 100A of the present embodiment, it is preferable that the separating unit 100 is disposed so as to be able to come into contact with or be separated from the second roller 86b, and the separating unit 100 can be selectively in contact with or in non-contact with the surface of the second roller 86b. According to this configuration, since the separating unit 100 is disposed so as to be able to come into contact with or be separated from the second roller 86b, when the sheet S adhering to the second roller 86b is separated, the separating unit 100 comes into contact with the surface of the second roller 86b, and after the sheet S is separated, the separating unit 100 is in non-contact, that is, the separating unit 100 is separated from the second roller 86b. As a result, damage to the second roller 86b can be suppressed.
In addition, in the sheet separating apparatus 100A of the present embodiment, the separating plate 200 is preferably made of polyimide. According to this configuration, since the separating plate 200 is made of polyimide, the separating plate 200 is highly heat-resistant, and in addition, is less likely to damage the second roller 86b when coming into contact with the second roller 86b.
In addition, the sheet manufacturing apparatus 1000 of the present embodiment includes the supply unit 10 that supplies a raw material, the deposition unit 60 that accumulates a part of the raw material and forms the sheet S, the pressing unit 80 that presses the sheet S, and the cutting unit 90 that cuts the sheet S. The pressing unit 80 includes the rollers 86a and 86b that transport the sheet S while heating the sheet S, and the separating unit 100 that includes the separating plate 200 having the leading end portion 201 that comes into contact with the second roller 86b of the rollers 86a and 86b, and the supporting portion 300 that supports the separating plate 200. The separating plate 200 is provided with the slits 210 that absorb bending due to a thermal expansion difference between the separating plate 200 and the supporting portion 300.
According to this configuration, even when the sheet S is heated and the heat is transmitted to the separating plate 200 and the supporting portion 300, since the separating plate 200 is provided with the slits 210, bending due to the thermal expansion difference between the separating plate 200 and the supporting portion 300 can be absorbed by the slits 210. Therefore, bending of the leading end portion 201, in the separating plate 200, that comes into contact with the sheet S, in other words, occurrence of warping can be suppressed. As a result, the leading end portion 201 of the separating plate 200 can come into contact with the second roller 86b without a gap, and the sheet S adhering to the second roller 86b can be separated from the second roller 86b. As a result, the sheet S can be reliably transported downstream.
Hereinafter, a modification of the above-described embodiment will be described.
The contact between the separating plate 200 and the leading end portion S1 of the sheet S is not limited to a surface contact, as described in the above-described embodiment, and the contact may be made as illustrated in
As described above, it is possible to reduce the resistance when the separating plate 200A is in contact with the sheet S, and even when there is a gap to some extent between the sheet S and the second roller 86b, jamming of the sheet S can be prevented.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-073106 | Apr 2023 | JP | national |
