Sheet Manufacturing Apparatus and Humidifying Apparatus

The present application is based on, and claims priority from JP Application Serial Number 2024-087762, filed May 30, 2024 and JP Application Serial Number 2025-015926, filed Feb. 3, 2025, the disclosures of which are hereby incorporated by reference herein in their entirety.

The present disclosure relates to a sheet manufacturing apparatus and a humidifying apparatus.

In the related art, an apparatus for manufacturing a sheet from fibers derived from used paper or the like by a dry process has been known. Some of such apparatuses include a humidifying apparatus that humidifies fibers, a binder, and the like. For example, JP-A-2011-27377 discloses a humidifier that performs humidification by vaporizing water that has been stirred up by a disk.

However, there has been a demand for a method in which the apparatus side confirms the state of a water storage tank.

A sheet manufacturing apparatus includes a processing unit that defibrates a material and manufactures a sheet from obtained fibers, a humidifying case, and a humidified air generator that is attachable to and detachable from the humidifying case and humidifies air, the humidifying case includes a first sensor, the humidified air generator includes a water storage unit that stores water and a float unit that is displaced according to a water level of the water storage unit, and the first sensor detects that the float unit is located at a first position that is a position of the float unit in a state where the humidified air generator is set in the humidifying case and drainage of the water storage unit is completed.

A humidifying apparatus includes a drive unit, a first sensor, and a humidified air generator attachable to and detachable from the first sensor, the humidified air generator includes a water storage unit that stores water, and the first sensor detects a state where the humidified air generator is set and drainage of the water storage unit is completed.

In the following embodiment, a sheet manufacturing apparatusthat manufactures a sheet from a material such as used paper containing fibers and a humidifying apparatusincluded in the sheet manufacturing apparatuswill be exemplified and described with reference to the drawings.

In each of the following drawings, XYZ-axes are given as coordinate axes orthogonal to each other, a direction indicated by each arrow is set as a positive direction, and a direction opposite to the positive direction is set as a negative direction. The Z-axis is a virtual axis extending in a vertical direction, a +Z direction is an upward direction, and a −Z direction is a downward direction. The −Z direction is the vertical direction. In addition, in the sheet manufacturing apparatus, a leading side in a transport direction of a material, a web, a sheet, or the like is downstream, and a going-back side in the transport direction is upstream. For convenience of illustration, the size of each member is different from the actual size.

As illustrated in, the sheet manufacturing apparatusaccording to the present embodiment includes a first unit group, a second unit group, and a third unit group. The first unit group, the second unit group, and the third unit groupare supported by a frame (not illustrated). In, directions in which paper pieces C, a sheet P, a slit piece S, unnecessary scraps, and the like move are indicated by white arrows. In the following description, a collection of a plurality of paper pieces C is also simply referred to as the paper piece C.

The sheet manufacturing apparatusmanufactures the sheet Pfrom the paper piece C that is a material containing fibers such as used paper. In the sheet manufacturing apparatus, the first unit group, the third unit group, and the second unit groupare arranged from a −Y direction to a +Y direction in side view in a −X direction.

The paper piece C is transported from the first unit groupto the second unit groupthrough a pipecrossing the inside of the third unit group. The paper piece C is then defibrated in the second unit groupto form a defibrated material, which is an aggregate of fibers, and a binder or the like is added to the defibrated material. The defibrated material is transported to the third unit groupthrough a pipe. The defibrated material is formed into a web W in the third unit groupand then formed into a strip-shaped sheet P. The strip-shaped sheet Pis cut into the sheet Pin the first unit group.

The first unit groupincludes a buffer tank, a fixed-quantity supply unit, a merging unit, and the pipe. In the first unit group, these components are arranged in this order from upstream to downstream. The first unit groupalso includes a first cutting unit, a second cutting unit, a tray, and a shredding unit.

In addition, a sheet transport unitis disposed from the third unit groupto the first unit group. The sheet transport unittransports the strip-shaped sheet P, a single-cut sheet P, the sheet P, and the slit piece S. The first cutting unitand the second cutting unitcut the strip-shaped sheet Pinto the sheet Phaving a predetermined shape.

The first unit groupalso includes a water supply tank. The water supply tankis a water storage tank. The water supply tanksupplies water for humidification to each of a mist humidifierand the humidifying apparatus, which will be described later, through a hose or the like (not illustrated). Pure water, tap water, or the like can be used as the water stored in the water supply tank. The humidifying apparatusis an example of the humidifying apparatus of the present disclosure.

The paper piece C is input from a raw material input portto the buffer tank. The paper piece C contains fibers such as cellulose and is, for example, shredded used paper. Humidified air is supplied to the inside of the buffer tankfrom the humidifying apparatusprovided in the third unit group. As a result, the paper piece C is not easily charged, and adhesion of the paper pieces C to each other is suppressed.

The paper piece C to be defibrated is temporarily stored in the buffer tankand is then transported to the fixed-quantity supply unitaccording to the operation of the sheet manufacturing apparatus. The sheet manufacturing apparatusmay include a shredder that shreds the paper piece C and the like upstream of the buffer tank.

The fixed-quantity supply unitincludes a weighing deviceand a supply mechanism (not illustrated). The weighing deviceweighs a mass of the paper piece C. The supply mechanism supplies the paper piece C weighed by the weighing deviceto the merging unitlocated downstream. That is, the fixed-quantity supply unitweighs the paper piece C by each predetermined mass using the weighing deviceand supplies the paper piece C to the merging unitlocated downstream by the supply mechanism.

Both digital and analog measuring mechanisms can be applied to the weighing device. The predetermined mass for which the paper piece C is weighed by the weighing deviceis, for example, approximately several grams to several tens of grams.

A known technique such as a vibration feeder can be applied to the supply mechanism. The supply mechanism may be included in the weighing device

The weighing and supplying of the paper piece C in the fixed-quantity supply unitis batch processing. That is, the paper piece C is intermittently supplied from the fixed-quantity supply unitto the merging unit. The fixed-quantity supply unitmay include a plurality of weighing devices, and the plurality of weighing devicesmay be operated at different times to improve the weighing efficiency.

In the merging unit, shredded pieces of the slit piece S supplied from the shredding unitare merged and mixed with the paper piece C supplied from the fixed-quantity supply unit. The slit piece S and the shredding unitwill be described later. The paper piece C mixed with the above-described shredded pieces flows into the pipefrom the merging unit.

The pipeallows the paper piece C to transport therethrough from the first unit groupto the second unit groupusing an airflow generated by a blower (not illustrated).

The second unit groupincludes a defibrating unit, which is a dry defibrator, a separator, a pipe, a powder supply unit, a mixing unit, and the pipe. In the second unit group, these components are arranged in this order from upstream to downstream. The second unit groupalso includes a control unit, a capturing unit, a compressor, a power supply unit, and a pipeand an airflow pipeconnected to the separator.

The paper piece C transported through the pipeflows into the defibrating unit. The defibrating unitdefibrates the paper piece C, which is a material containing fibers, by a dry method and generates a defibrated material containing fibers. A known defibrating mechanism can be applied to the defibrating unit. In the present embodiment, a defibrating mechanism including a rotary blade is used as the defibrating unit. The defibrating mechanism generates fibers by shredding and defibrating the paper piece C with the rotary blade.

Tangled fibers contained in the paper piece C are untangled by the defibrating unitto form a defibrated material containing fibers, and the defibrated material is transported to the separator.

The separatorsorts the defibrated fibers. Specifically, the separatorremoves components contained in the fibers and unnecessary for manufacturing the sheet P. The separatorseparates relatively long fibers from relatively short fibers. The relatively short fibers, which may lower the strength of the sheet P, are sorted and removed by the separator. The separatoralso removes impurities such as coloring materials and additives contained in the paper piece C.

A known separation mechanism can be applied to the separator. In the present embodiment, a disk-type separation mechanism including a separation filter is used as the separator. The separation mechanism sorts 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 fibers for the material of the web W.

Humidified air is supplied from the humidifying apparatusof the third unit groupto the inside of the separator. As a result, the defibrated fibers are not easily charged, and attachment of the fibers to each other and adhesion of the fibers to the separatorare suppressed.

Relatively short fibers and the like are removed from the defibrated fibers in the separator. The defibrated fibers are then transported to the mixing unitthrough the pipeby an airflow generated by a blower (not illustrated) disposed at a leading end of the airflow pipe. Unnecessary components such as relatively short fibers and impurities are sucked by a suction device (not illustrated) of the capturing unitand are discharged from the pipeto the capturing unit.

The capturing unitincludes a filter (not illustrated). The filter filters out unnecessary components such as relatively short fibers transported through the pipeby an airflow.

The compressorgenerates compressed air. The above-described filter may be clogged with fine particles or the like of the unnecessary components. The filter can be cleaned by blowing the compressed air generated by the compressoronto the filter to blow off adhering particles.

The power supply unitincludes a power supply device (not illustrated) that supplies power to the sheet manufacturing apparatusand the control unit. The power supply unitdistributes power supplied from the outside to each component of the sheet manufacturing apparatus.

The powder supply unitsupplies a binder, which is a powder, to the mixing unit. The mixing unitmixes the defibrated material and the binder supplied from the powder supply unitin air. The binder binds the fibers to each other in a forming unitdescribed later. In the present embodiment, starch is used as the binder, but a thermoplastic resin or the like may also be used.

The powder supply unitincludes a powder storage unit and a powder transport unit (not illustrated). The powder storage unit is attachable to and detachable from a main body of the powder supply unit. The powder storage unit can be removed from the powder supply unitto be filled with the binder or transported. The powder transport unit is, for example, an auger-type screw, but other methods such as transporting by a wind force may be adopted. The powder transport unit supplies a fixed amount of the binder per unit time to the mixing unitwhile transporting the binder.

The powder supplied from the powder supply unitto the mixing unitis not limited to the binder and may be other additives such as a coloring material, for example. In addition, the above-described powder may be a mixture of the binder and other additives. Moreover, the sheet manufacturing apparatusmay include a plurality of powder supply units.

The mixing unitmixes a powder with the defibrated material, which is fibers, in air. Although not illustrated, the mixing unitincludes a flow path through which the fibers are transported and a fan. The fan of the mixing unitmixes the binder and the like in air while transporting the defibrated material downstream using a generated airflow. The defibrated material then flows into the pipefrom the mixing unit.

The control unitis electrically connected to each component of the sheet manufacturing apparatusand integrally controls the operation of the sheet manufacturing apparatus. Although not illustrated, the control unitincludes a central processing unit (CPU) and a storage unit including a random access memory (RAM), a read only memory (ROM), and the like. Various programs for controlling the sheet manufacturing apparatusare stored in the storage unit. The control unitmay include dedicated hardware (application specific integrated circuit: ASIC) that executes at least some of various processes. That is, the control unitmay be configured as one or more processors that operate according to a computer program (software), one or more dedicated hardware circuits such as ASICs, or a circuit including a combination thereof.

The processor includes a CPU and a memory such as a RAM and a ROM. The memory stores program codes or instructions configured to cause the CPU to perform processes. The memory, that is, a computer-readable medium includes any medium that can be accessed by a general-purpose or dedicated computer.

Although not illustrated, an operation panel is provided on the exterior of the sheet manufacturing apparatus. The control unitis electrically connected to the operation panel. The user of the sheet manufacturing apparatusoperates the sheet manufacturing apparatusthrough the operation panel. The operation panel is, for example, a touch panel type liquid crystal display device and mechanical keys.

The third unit groupaccumulates and compresses the defibrated material containing the binder and forms the defibrated material into the strip-shaped sheet P. The third unit groupincludes an accumulation unit, a transport unit, the mist humidifier, the humidifying apparatus, a drainage tank, the forming unit, and the sheet transport unit. In the third unit group, the accumulation unit, the transport unit, and the forming unitare arranged in this order from upstream to downstream. That is, the transport unitis disposed between the accumulation unitand the forming unit. The humidifying apparatusis disposed in a lower portion of the third unit group.

Here, the sheet manufacturing apparatus of the present disclosure includes a processing unit, and the processing unit defibrates a material and manufactures a sheet from obtained fibers. In the present embodiment, among the components of the sheet manufacturing apparatus, the defibrating unit, the separator, the accumulation unit, the transport unit, the forming unit, and the like correspond to the processing unit of the present disclosure. The humidifying apparatushumidifies the separatorand the accumulation unitof the processing unit. The humidifying apparatusis not limited to humidifying the separatorand the accumulation unit. The humidifying apparatusmay humidify other components of the processing unit, or may humidify the buffer tankas described above.

The transport unitincludes an accumulation transport unitand a back surface transport unit. The transport unittransports the web W formed in the accumulation unitto the forming unitlocated downstream. In the transport direction of the web W, the accumulation transport unitis disposed upstream of the back surface transport unit. A downstream portion of the accumulation transport unitand an upstream portion of the back surface transport unitpartially face each other in the vertical direction. The mist humidifieris disposed below the back surface transport unit.

The accumulation unitaccumulates the defibrated material containing the binder and the like using an airflow and gravity to form the web W. The accumulation unitincludes a drum member, a blade memberdisposed in the drum member, a housingthat houses the drum member, and a suction unit. The defibrated material is taken into the drum memberfrom the pipe.

The accumulation transport unitis disposed below the accumulation unit. The accumulation transport unitincludes a mesh beltand five tension rollers (not illustrated) for tensioning the mesh belt. The suction unitfaces the drum memberwith the mesh beltinterposed therebetween in a direction along the Z-axis.

The blade memberis disposed inside the drum memberand is rotationally driven by an electric motor (not illustrated). The drum memberis a semicircular columnar sieve. A mesh having a function of a sieve is provided on a side surface of the drum memberfacing downward. The drum memberallows particles such as the fibers of the defibrated material and the binder, which are smaller than the size of mesh openings of the sieve, to pass through the mesh openings from the inside to the outside.

The defibrated material is discharged to the outside of the drum memberwhile being stirred by the rotating blade memberin the drum member. Humidified air is supplied from the humidifying apparatusto the inside of the drum member. As a result, the fibers, the binder, and the like are not easily charged, and attachment of the fibers to each other and adhesion of the fibers to the drum member, the blade member, and the like are suppressed.

The suction unitis disposed below the drum member. The suction unitsucks air in the housingthrough a plurality of holes of the mesh belt. As a result, an airflow for causing the defibrated material to accumulate on the mesh beltis generated. The plurality of holes of the mesh beltallows air to pass therethrough but does not allow the fibers, the binder, and the like contained in the defibrated material to pass therethrough easily. As a result, the defibrated material discharged to the outside of the drum memberis sucked downward together with the air. The suction unitis a known suction device such as a suction fan.

The defibrated material containing the binder and the like is dispersed in the air inside the housingand accumulates on an upper surface of the mesh beltby gravity and the airflow generated by the suction unitto form the web W.

The mesh beltof the accumulation transport unitis an endless belt and is tensioned by the five tension rollers. The mesh beltis rotated counterclockwise inby the rotation of the tension rollers. As a result, the defibrated material continuously accumulates on the mesh belt, and the web W is formed. The web W contains a relatively large amount of air and is soft and swollen. The accumulation transport unittransports the formed web W downstream by the rotation of the mesh belt.

The back surface transport unittransports the web W delivered from the accumulation transport unitdownstream of the accumulation transport unit. The back surface transport unitpeels the web W from the upper surface of the mesh beltand transports the web W toward the forming unit. The back surface transport unitis disposed above the transport path of the web W and slightly upstream of a starting point on a return side of the mesh belt, that is, an end portion in the −Y direction. The +Y direction of the back surface transport unitand the −Y direction of the mesh beltpartially overlap each other in the vertical direction.