JP2014124892A - Waste ink absorber, waste ink tank, droplet discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste ink absorber having excellent permeability and retention.SOLUTION: A waste ink absorber that is incorporated in a waste ink tank and absorbs waste ink discharged from a head for jetting ink has: a sparse portion having a low density; and a dense portion having a higher density than that of the sparse portion in a direction of a plane having the widest surface area in one waste ink absorber that is not incorporated in the waste ink tank.

Description

  The present invention relates to a waste ink absorber, a waste ink tank, and a droplet discharge device.

  2. Description of the Related Art Conventionally, there is known a liquid ejecting apparatus that includes a waste liquid container into which liquid discharged from an ejection head flows, and a waste liquid absorbing material that is provided in the waste liquid container and absorbs liquid that has flowed into the waste liquid container ( For example, see Patent Document 1).

JP 2011-167960 A

  However, since the density of the waste liquid absorbent material provided in the above apparatus is almost uniform, if the waste liquid permeability is relatively good with respect to the waste liquid absorbent material, the retainability for retaining the absorbed waste liquid is reduced. On the other hand, when the retention of the waste liquid absorbed with respect to the waste liquid absorbent material is relatively good, there is a problem that the permeability to absorb the waste liquid is reduced.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A waste ink absorber according to this application example is a waste ink absorber that absorbs waste ink discharged from a head that ejects ink and is incorporated in a waste ink tank, and is disposed in the waste ink tank. One waste ink absorber that is not incorporated has a sparse portion in a direction along a plane having the largest surface area, and a dense portion that has a higher density than the sparse portion. To do.

  According to this configuration, the waste ink can be easily penetrated in the sparse part. Further, the permeated waste ink can be held in the dense portion. Therefore, it is possible to provide a waste ink absorber having excellent permeability and retention. The waste ink is, for example, ink that has been ejected from the head and has not reached the medium. Specifically, flushing that ejects ink for the purpose of preventing thickening, recovery of nozzles that cannot be ejected due to the effect of thickening, meniscus destruction, paper dust, or pumping ink for the purpose of preventing thickening, etc. This is the ink generated by cleaning that is forcibly discharged. Further, in so-called borderless printing, ink that has been removed from the medium is also included in the waste ink because it does not reach the medium.

  Application Example 2 The waste ink absorber according to the application example described above is characterized in that the thickness of the waste ink absorber is constant when not incorporated into the waste ink tank.

  According to this configuration, since the thickness is constant, a plurality of waste ink absorbers can be easily stacked. For example, it can be easily incorporated into a waste ink tank.

  Application Example 3 A waste ink tank according to this application example includes the above-described waste ink absorber and a storage unit that stores the waste ink absorber.

  According to this configuration, by accommodating the waste ink absorber having the permeability and retention of waste ink, for example, even when the waste ink tank is disposed obliquely or horizontally, the absorbed waste ink is removed. Hold and prevent leakage.

  Application Example 4 A droplet discharge device according to this application example includes a head that ejects ink and the waste ink tank that captures the waste ink discharged from the head.

  According to this configuration, it is possible to provide a highly reliable liquid droplet ejection apparatus that efficiently absorbs waste ink and does not cause problems such as ink leakage.

FIG. 3 is a schematic diagram illustrating a configuration of a waste ink absorber according to the first embodiment. Schematic which shows the structure of the waste ink tank concerning 1st Embodiment. The schematic diagram which shows the structure of the waste ink absorber concerning 2nd Embodiment. Schematic which shows the structure of the waste ink tank concerning 2nd Embodiment. Schematic which shows the structure of a droplet discharge apparatus. FIG. 6 is a process diagram illustrating a method for forming a waste ink absorber according to the first embodiment. FIG. 9 is a process diagram illustrating a method for forming a waste ink absorber according to a second embodiment. The schematic diagram which shows the evaluation method of the ink permeability of a waste ink absorber, and retainability.

  Hereinafter, first and second embodiments according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member or the like is shown differently from the actual scale so as to make each member or the like recognizable.

[First Embodiment]
First, the configuration of the waste ink absorber will be described. FIG. 1 is a schematic diagram illustrating a configuration of a waste ink absorber according to the first embodiment. The rectangular parallelepiped waste ink absorber 200 absorbs waste ink discharged from a head that ejects ink, and is incorporated into, for example, a waste ink tank, and is not incorporated into the waste ink tank as shown in FIG. One waste ink absorber 200 has a sparse portion 220 in the direction of the flat surface 201 having the largest surface area and a dense portion 210 having a higher density than the sparse portion 220. In the present embodiment, a dense portion 210 is formed in one portion of the plane 201 in the longitudinal direction, and a sparse portion 220 is formed in the other portion. The thickness of the waste ink absorber 200 is constant when the waste ink absorber 200 is not incorporated into the waste ink tank, in other words, when the waste ink absorber 200 is not deformed by being compressed.

  In the waste ink absorber 200 formed in this way, the waste ink can be easily permeated in the sparse part 220, and the absorbed waste ink can be held in the dense part 210. Can do.

  The waste ink absorber 200 is composed of a mixture containing cellulose fibers, a molten resin, and a flame retardant. Cellulose fibers are defibrated pulp sheets, for example, using a dry defibrator such as a rotary crusher. The molten resin bonds the cellulose fibers, maintains an appropriate strength (hardness, etc.) in the waste ink absorber 200, prevents paper dust and fibers from scattering, and maintains the shape when absorbing the waste ink. It contributes to. Various forms, such as fibrous form and powder form, are employable as molten resin. And by heating the mixture which mixed the cellulose fiber and molten resin, a molten resin can be fuse | melted and it can be made to fuse | fuse and solidify to a cellulose fiber. It is desirable to fuse the cellulose fibers and the like at a temperature that does not cause thermal degradation. In addition, the molten resin is preferably in the form of fibers that are easily entangled with the paper fibers in the defibrated material. Furthermore, a core-sheath composite fiber is desirable. The core-sheath-structured molten resin can be firmly bonded by melting the surrounding sheath at a low temperature and bonding the fibrous core to the molten resin itself or cellulose fibers.

  The flame retardant is added to impart flame retardancy to the waste ink absorber 200. As the flame retardant, for example, an inorganic material such as aluminum hydroxide or magnesium hydroxide, or a phosphorus organic material (for example, an aromatic phosphate such as triphenyl phosphate) can be used.

  As a method for forming the waste ink absorber 200, for example, a mixture of cellulose fibers, molten resin, and a flame retardant is passed through a sieve, and deposited on a mesh belt disposed below the sieve so as to have a predetermined shape. To form a deposit. The formed deposit is subjected to pressure heat treatment. As a result, the molten resin is dissolved and formed in a desired thickness. Further, the waste ink absorber 200 is formed by die cutting to a desired dimension.

  Next, the configuration of the waste ink tank will be described. FIG. 2 shows a configuration of the waste ink tank according to the first embodiment, and FIG. 2A is a cross-sectional view. As shown in FIG. 2A, the waste ink tank 300 includes a waste ink absorber 200 that absorbs waste ink, and a storage unit 170 that stores the waste ink absorber 200.

  The accommodating portion 170 that accommodates the waste ink absorber 200 is formed in a rectangular shape by a plastic material, for example. The accommodating portion 170 includes a bottom surface portion 170a and a side surface portion 170b, and is configured to accommodate and hold the waste ink absorber 200.

  The configuration of the waste ink absorber 200 is the same as that in FIG. In the present embodiment, a plurality of waste ink absorbers 200 are stacked. In FIG. 2A, the dense portion 210 is disposed so as to be in contact with the bottom surface portion 170a. In this case, it is preferable to arrange the discharge port of the pipe P through which the waste ink is discharged at a position facing the sparse portion 220.

  When the waste ink is discharged toward the waste ink absorber 200 through the pipe P, the waste ink comes into contact with the sparse portion 220 of the waste ink absorber 200 and the waste ink penetrates into the waste ink absorber 200. The absorbed waste ink is held by the dense portion 210.

  Next, the configuration of another waste ink tank will be described. FIG. 2B is a cross-sectional view showing the configuration of another waste ink tank. The configuration of the waste ink absorber 200 is the same as that shown in FIG. In FIG. 2B, a plurality of waste ink absorbers 200 are stacked. And the sparse part 220 is arrange | positioned so that the bottom face part 170a side may be touched. In this case, it is preferable to insert the pipe P into the sparse part 220 so that the discharge port of the pipe P from which the waste ink is discharged is located in the sparse part 220. By having such a configuration, the discharged waste ink can be easily penetrated into the waste ink absorber 200 and the absorbed waste ink can be held as described above.

[Second Embodiment]
Next, a second embodiment will be described.

  First, the configuration of the waste ink absorber will be described. FIG. 3 is a schematic diagram illustrating a configuration of a waste ink absorber according to the second embodiment. The waste ink absorber 200a absorbs waste ink discharged from a head that ejects ink, and is incorporated in, for example, a waste ink tank. As shown in FIG. 3, one sheet that is not incorporated in the waste ink tank. The waste ink absorber 200 a includes a sparse portion 220 in the direction of the flat surface 201 having the largest surface area and a dense portion 210 having a higher density than the sparse portion 220. In the present embodiment, dense portions 210 are formed on both end sides in the longitudinal direction of the plane 201, and sparse portions 220 are formed in the central portion. And in the state which is not integrated in a waste ink tank, the thickness of the waste ink absorber 200a is constant.

  In the waste ink absorber 200a formed in this way, the waste ink can be easily penetrated in the sparse part 220, and the absorbed waste ink can be held in the dense part 210. Can do. Note that the mixture and formation method of the waste ink absorber 200a are the same as those in the first embodiment, and a description thereof will be omitted.

  Next, the configuration of the waste ink tank will be described. FIG. 4 is a cross-sectional view illustrating a configuration of a waste ink tank according to the second embodiment. As shown in FIG. 4, the waste ink tank 300b includes a waste ink absorber 200a that absorbs the waste ink, and a storage unit 170 that stores the waste ink absorber 200a.

  The accommodating portion 170 that accommodates the waste ink absorber 200a is formed in a rectangular shape with a plastic material, for example. The accommodating portion 170 includes a bottom surface portion 170a and a side surface portion 170b, and is configured to be able to accommodate and hold the waste ink absorber 200a.

  The configuration of the waste ink absorber 200a is the same as the configuration in FIG. In the present embodiment, the waste ink absorber 200a is arranged so that the longitudinal direction of the plane 201 is the horizontal direction. A lid 180 is provided so as to be in contact with the surface opposite to the surface in contact with the bottom surface 170a of the waste ink absorber 200a. The lid portion 180 is installed so as to cover the surface portion of the sparse portion 220 of the waste ink absorber 200a. In other words, the lid portion 180 is provided so that the surface portion of the dense portion 210 of the waste ink absorber 200a is released.

  The lid portion 180 includes a hollow cylinder 180a, and a pipe P through which waste ink is discharged is connected to the cylinder 180a. In this case, when the waste ink is discharged toward the waste ink absorber 200a through the pipe P, the waste ink contacts the sparse part 220 of the waste ink absorber 200a, and the waste ink penetrates into the waste ink absorber 200a. . If the solvent of the ink evaporates during the permeation process, the viscosity of the ink increases, so that it becomes difficult to permeate. Therefore, the lid portion 180 is brought into contact with the sparse portion 220 to suppress ink evaporation and to facilitate ink permeation. The absorbed waste ink is held by the dense portion 210. Further, since the surface portion of the dense portion 210 is open, waste ink held in the dense portion 210 can be easily evaporated. For example, if the surface portion of the dense part 210 is covered, the waste ink is not evaporated, so that the waste ink is accumulated. Since the amount of waste ink that can be held by the waste ink absorber 200a is limited, the amount of waste ink that can be held can be increased by opening the portion corresponding to the dense portion 210 and evaporating the waste ink. The lid 180 does not compress the waste ink absorber 200a. The lid 180 only needs to cover at least the sparse portion 220, and a gap may be provided between the lid 180 and the waste ink absorber 200a as long as evaporation of the ink solvent can be suppressed.

  Next, the configuration of the droplet discharge device will be described. The droplet discharge device includes a head that ejects ink and a waste ink tank that captures waste ink discharged from the head. In the droplet discharge device of the present embodiment, a configuration including the waste ink absorber 200 (200a) and the waste ink tank 300 (300a, 300b) will be described.

  FIG. 5 is a schematic diagram showing the configuration of the droplet discharge device. As shown in FIG. 5, the droplet discharge device 10 includes a carriage 20 that forms ink dots on a printing medium 2 such as printing paper while reciprocating in the main scanning direction, and a drive mechanism 30 that reciprocates the carriage 20. A platen roller 40 for feeding the print medium 2 and a maintenance mechanism 100 for performing maintenance so that printing can be normally performed. In the carriage 20, an ink cartridge 26 that contains ink, a carriage case 22 in which the ink cartridge 26 is mounted, and a head 24 that ejects ink mounted on the bottom surface side (side facing the print medium 2) of the carriage case 22. Etc. are provided. The head 24 is formed with a plurality of nozzles for ejecting ink. The ink in the ink cartridge 26 is guided to the head 24, and the ink is ejected from the nozzles to the printing medium 2 by an accurate amount, whereby an image is formed. It is supposed to be printed.

  A drive mechanism 30 that reciprocates the carriage 20 includes a guide rail 38 that extends in the main scanning direction, a timing belt 32 that has a plurality of teeth formed therein, a drive pulley 34 that meshes with the teeth of the timing belt 32, A step motor 36 for driving the drive pulley 34 and the like are included. A part of the timing belt 32 is fixed to the carriage case 22, and the carriage case 22 can be moved along the guide rail 38 by driving the timing belt 32. Further, since the timing belt 32 and the drive pulley 34 are engaged with each other by the tooth profile, when the drive pulley 34 is driven by the step motor 36, the carriage case 22 can be moved with high accuracy according to the drive amount. .

  The platen roller 40 that feeds the print medium 2 is driven by a drive motor or a gear mechanism (not shown) and can feed the print medium 2 by a predetermined amount in the sub-scanning direction.

  Further, the maintenance mechanism 100 is provided in a region called a home position outside the printing region, and the wiper blade 110 that wipes the surface (nozzle surface) on which the ejection nozzle is formed on the bottom surface side of the head 24, and the head 24. A cap unit 120 that is pressed against the nozzle surface and caps the head 24, and a suction pump 150 that discharges the ink as waste ink by driving the head 24 with the cap unit 120 capped. By forcibly discharging the ink from the head 24 by the suction pump 150, it is possible to recover the nozzle that cannot be ejected due to thickening, meniscus destruction, paper dust, etc., or to prevent thickening of the ink in the nozzle. To do. Further, below the suction pump 150, a waste ink tank 300 (300a, 300b) that captures the waste ink discharged from the suction pump 150 is provided. By providing the waste ink tank 300, the outer shape of the droplet discharge device 10 is increased. By improving the ink permeability and retention of the waste ink absorber 200, the volume of the waste ink absorber 200 that can hold the same ink amount can be reduced. Thereby, the size of the waste ink tank 300 and the droplet discharge device 10 is also reduced. The waste ink tank 300 (300a, 300b) has the same configuration as that described with reference to FIGS. In addition, the discharged waste ink includes ink that does not reach the medium, such as ink by flushing that ejects ink for the purpose of preventing thickening, and ink that has been removed from the medium in so-called borderless printing. Therefore, it is not always the ink discharged by the suction pump 150. Waste ink refers to ink that has been ejected from the head 24 and has not reached the medium.

  As mentioned above, according to the said embodiment, the following effects can be acquired.

  (1) The waste ink absorbers 200 and 200a have a dense portion 210 and a dense portion 220 in the direction of the flat surface 201 having the largest surface area. As a result, it is possible to improve the permeability for allowing waste ink to permeate in the sparse part 220 and to improve the retention for holding the permeated waste ink in the dense part 210. Therefore, it is possible to provide the waste ink absorbers 200 and 200a having penetrability and retention.

  (2) In the waste ink tanks 300, 300a, 300b provided with the waste ink absorbers 200, 200a, the absorbed waste ink is absorbed even when the waste ink tanks 300, 300a, 300b are arranged obliquely or horizontally. It is possible to prevent leakage and the like.

  (3) In the droplet discharge device 10 provided with the waste ink tanks 300, 300a, 300b, the waste ink discharged from the head 24 is efficiently absorbed, and the occurrence of problems such as ink leakage is prevented and reliability is improved. Can be secured.

[Example]
Next, specific examples according to the present invention will be described.

  1. blend

(1) Cellulose fiber A pulp sheet cut into several centimeters using a cutting machine was defibrated into a cotton shape with a turbo mill (manufactured by Turbo Kogyo Co., Ltd.).

(2) Molten resin A 1.7 dtex molten fiber (Tetron, manufactured by Teijin Ltd.) which has a core-sheath structure, the sheath melts at 100 ° C. or more, and the core is made of polyester.

(3) Flame retardant Aluminum hydroxide B53 (manufactured by Nippon Light Metal Co., Ltd.).

2. Formation of waste ink absorber (Example 1: Formation of waste ink absorber A)
FIG. 6 is a process diagram illustrating a method of forming a waste ink absorber according to the first embodiment. First, as shown in FIG. 6 (a), a mixture C1 in which 100 parts by weight of cellulose fibers, 15 parts by weight of molten fibers and 10 parts by weight of a flame retardant are mixed in the air is passed through a sieve and deposited on the mesh belt MB. Product A ′ was formed. At this time, deposition was performed such that the thickness was different from the mesh belt MB surface. In this example, the deposit A ′ was formed so that the thickness of one end portion was larger than the thickness of the other end portion. And deposit A 'was pressure-heat-treated at 200 degreeC. At this time, as shown in FIGS. 6B and 6C, the heated flat plate H was pressed against the deposit A ′ and compressed to a predetermined thickness. In this embodiment, the deposit A ′ is formed such that the thickest portion of the deposit A ′ is compressed to 1/8 and the thinnest portion is compressed to 1/5 to form a predetermined thickness (see FIG. 6 (a)). Then, it cut out to 150 mm x 50 mm x 12 mm, and formed the waste ink absorber A. When the density of the waste ink absorber A is observed, a dense portion is formed in the portion corresponding to the thickest portion in the deposit A ′ in the direction of the plane Aa, and a sparse portion is formed in the portion corresponding to the thinnest portion. The part of was formed. In the waste ink absorber A, the density has shifted from dense to sparse in the deposit A ′ from the thickest part to the thinnest part. Density was 0.13 g / cm ³ at the smallest 0.21 g / cm ³ at the largest.

(Example 2: Formation of waste ink absorber B)
FIG. 7 is a process diagram illustrating a method of forming a waste ink absorber according to the second embodiment. First, as shown in FIG. 7A, a mixture C1 in which 100 parts by weight of cellulose fibers, 15 parts by weight of molten fibers, and 10 parts by weight of a flame retardant are mixed in the air is passed through a sieve and deposited on the mesh belt MB. Product B ′ was formed. At this time, deposition was performed such that the thickness was different from the mesh belt MB surface. In this example, the deposit B ′ was formed such that the thickness at both ends was greater than the thickness at the center. Then, the deposit B ′ was subjected to pressure heat treatment at 200 ° C. At this time, as shown in FIGS. 7B and 7C, the flat plate H heated at 220 ° C. was pressed against the deposit B ′ and compressed to a predetermined thickness. In the present embodiment, the deposit B ′ is formed such that the thickest portion of the deposit B ′ is compressed to 1/8 and the thinnest portion is compressed to 1/5 to form a predetermined thickness (see FIG. 7 (a)). Then, it cut out to 150 mm x 50 mm x 12 mm, and formed the waste ink absorber B. When the density of the waste ink absorber B is observed, a dense portion is formed in the portion corresponding to the thickest portion in the deposit B ′ in the direction of the plane Ba, and a sparse portion is formed in the portion corresponding to the thinnest portion. The part of was formed. In the waste ink absorber B, the density has shifted from dense to sparse from the thickest part to the thinnest part in the deposit B ′. Density was 0.13 g / cm ³ at the smallest 0.21 g / cm ³ at the largest.

(Comparative Example 1: Formation of waste ink absorber R)
A mixture C1 in which 100 parts by weight of cellulose fiber, 15 parts by weight of molten fiber and 10 parts by weight of a flame retardant were mixed in the air was passed through a sieve and deposited on a mesh belt to form a deposit. At this time, deposition was performed so that the thickness was uniform with respect to the mesh belt MB surface. And the deposit was pressure-heat-treated at 200 degreeC. At this time, a flat plate heated at 220 ° C. was pressed against the deposit and compressed to a predetermined thickness. Thereafter, the waste ink absorber R was formed by cutting into 150 mm × 50 mm × 12 mm. When the density of the waste ink absorber R was observed, the density was uniform and 0.15 g / cm ³ in the direction along the plane.

3. Evaluation Next, in Example 1, Example 2, and Comparative Example 1 described above, ink permeability, ink retention, and ink deposition were evaluated. Each evaluation method is as follows.

(A) Evaluation Method of Ink Penetration Property and Ink Retention Property FIG. 8 is a schematic diagram showing an evaluation method of ink permeability and retention property of the waste ink absorber. As shown in FIG. 8A, an ink absorber F of 150 mm (L) × 50 mm (W) × 12 mm (H) is placed on a flat surface, and 80 ml of ink is slowly injected from the first point P1 on the upper surface. To do.
In Example 1, ink is injected from a sparse part at one end of the waste ink absorber A. In the second embodiment, ink is injected from a sparse portion at the center of the end of the waste ink absorber B. If the absorbent body F does not soak, leave it for 5 minutes, and then continue the injection. If the ink does not soak even after being left for 5 minutes, it is considered that the ink does not permeate, and the ink permeability determination is NG. On the other hand, if all of the ink can be injected, the ink permeability determination is OK.
When all the ink has been injected, the ink is allowed to stand for 5 minutes, and as shown in FIG. 8B, the first point P1 where the ink is injected from the second point P2 using the strap S or the like is downward. Hang like so. In such a suspended state, the permeated ink gathers at one end of the ink absorber F and becomes difficult to be held. When the ink drips from the ink absorber F, it is considered that the ink cannot be held, and the determination of the ink holding property is NG. On the other hand, if the ink does not drip, the ink retention determination is OK. This evaluation shows that the ink does not leak even if the droplet discharge device or the waste ink tank is inclined.

(B) Method for evaluating ink deposition property An ink absorber F of 150 mm (L) × 50 mm (W) × 12 mm (H) is placed on a flat surface and placed in an environment of 40 ° C. and 20% RH. Then, 0.4 g of ink is dropped on the center of the upper surface of the absorber F once every hour. Then, after 240 hours, if the thickness of the solid deposit on the surface of the ink absorber F is less than 1 mm, the determination of the ink depositability is OK. On the other hand, if the thickness of the deposit is 1 mm or more, the ink deposition property is judged as NG.

  In the above examples and comparative examples, ink permeability, ink retention and ink deposition were evaluated. The evaluation results are as shown in Table 1.

  As shown in Table 1, according to the waste ink absorbers A and B (Examples 1 and 2) according to the present invention, they were excellent for all evaluations of ink permeability, ink retention, and ink deposition. . On the other hand, in Comparative Example 1, a satisfactory result was not obtained in ink retention. In Comparative Example 1, the density is sparse and uniform compared to the dense parts of Examples 1 and 2, so that the ink penetrates and does not accumulate, but cannot retain a large amount of ink. Since Examples 1 and 2 have a sparse part and a dense part, both ink permeability in the sparse part and ink retention in the dense part are satisfied. Further, since the ink is absorbed from the sparse part, the ink penetrates quickly and no deposit remains.

  The sparse part and the dense part, which are the feature points of the present application, may be visually recognized as the appearance, but may not be seen when the sparse and dense are slightly different. As a verification method in that case, it can be said that the density is different if the ease of permeation is different by dropping ink at different locations in the direction along the plane. When the entire waste ink absorber has a uniform density, the waste ink absorber penetrates almost evenly regardless of where it hangs down.

The above embodiment is adopted as the waste ink tank 300 (300a, 300b) and the waste ink absorbers 200, 200a used in the droplet discharge device 10. Here, the ink refers to various liquid compositions such as general water-based ink, oil-based ink, pigment ink, dye ink, solvent-based ink, resin-based ink, sublimation transfer ink, gel ink, hot-melt ink, and ultraviolet curable ink. It shall be included. Further, the ink may be any material that can be ejected by the head 24. For example, it may be in a state in which the substance is in a liquid phase, such as liquid crystals, liquids with high or low viscosity, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metals In addition to fluids such as melts) and liquids as a state of matter, functional material particles such as pigments and metal particles dissolved, dispersed or mixed in a solvent, etching liquid Including lubricating oil.
In addition to inkjet printers, for example, liquid droplet display devices such as liquid crystal displays, EL (electroluminescence) displays, surface-emitting displays, and materials such as electrode materials and color materials used in the manufacture of color filters are dispersed or dissolved. It may be a device for ejecting ink contained in a form, a device for ejecting biological organic materials used in biochip manufacturing, a device for ejecting ink as a sample used as a precision pipette, a textile printing device, a microdispenser, or the like. Furthermore, a device that injects lubricating oil pinpoint to precision machines such as watches and cameras, a device that forms micro hemispherical lenses (optical lenses) used in optical communication elements, etc. You may employ | adopt the apparatus which injects etching liquid, such as an apparatus to harden | cure, a board | substrate, etc., acid or alkali. The present invention can be applied to any one of these droplet discharge devices.

In the above embodiment, a thin non-woven fabric may be attached to the surface in order to prevent fluffing on the surface of the waste ink absorbers 200 and 200a. Since the nonwoven fabric to be attached is thinner than the waste ink absorbers 200 and 200a, there is little influence on the ink permeability and retention.
In the above embodiment, the waste ink absorber 200 is a rectangular parallelepiped, but is not limited thereto. A part of the rectangular parallelepiped may have a notch or a recess, and may have an arc portion or an inclined portion instead of the rectangular parallelepiped.
In the figure of the said Example, it drawn so that the ratio of a sparse part and a dense part might become substantially the same. This may be changed according to the ink. For example, if the ink has a high viscosity and is difficult to permeate, it is preferable that the ratio of the sparse part is larger than the ratio of the dense part to facilitate the permeation. On the contrary, if the viscosity is small and easy to penetrate, the ratio of the sparse part is preferably smaller than the ratio of the dense part. Moreover, the state which can understand a sparse part and a dense part may be sufficient, and the density may gradually increase from a sparse part to a dense part.
In addition, although the density was described in each Example and the comparative example, it is an example.

In the above-described embodiments, the pulp sheet includes wood pulp such as conifers and hardwoods, non-wood plant fibers such as hemp, cotton, and kenaf, and waste paper.
In the above-described embodiment, the cellulose fiber is mainly used. However, the material is not limited to the cellulose fiber as long as the material can absorb ink and provide a density difference. Fibers made from plastic such as polyurethane and polyethylene terephthalate (PET), and other fibers such as wool may be used.
The method of forming the waste ink absorber is not limited to the method described in the above embodiment. Other manufacturing methods such as a wet method may be used as long as the features of the present application can be obtained.

  DESCRIPTION OF SYMBOLS 10 ... Droplet discharge apparatus, 24 ... Head, 100 ... Maintenance mechanism, 170 ... Storage part, 180 ... Cover part, 200, 200a ... Waste ink absorber, 201 ... Plane, 210 ... Dense part, 220 ... Sparse part , 300, 300a, 300b ... Waste ink tanks.

Claims (4)

A waste ink absorber that absorbs waste ink discharged from a head that ejects ink and is incorporated in a waste ink tank,
In one waste ink absorber that is not incorporated in the waste ink tank, a portion having a sparse density in a direction along a plane having the largest surface area and a dense portion having a higher density than the sparse portion. A waste ink absorber comprising: The waste ink absorber according to claim 1,
A waste ink absorber, wherein the thickness of the waste ink absorber is constant in a state where the waste ink tank is not incorporated.   A waste ink tank comprising: the waste ink absorber according to claim 1; and a storage portion that stores the waste ink absorber. A head for ejecting ink;
A liquid droplet ejection apparatus comprising: the waste ink tank according to claim 3, which captures waste ink discharged from the head.