Printing device and printing method

Abstract

This printing device is provided with: a conveyance member capable of conveying media; an ink head for adhering pigment ink containing a pigment to the media on the conveyance member; a pretreatment liquid head for adhering a pretreatment liquid containing a component capable of forming an aggregate with the pigment to the media on the conveyance member; a liquid tank unit; and a recovery unit. The liquid tank unit includes: a liquid tank capable of accumulating a liquid L; and a transfer member capable of sending the pigment and component present on the conveyance member to the liquid tank. The recovery unit can recover the aggregate.

Description

Printing device and printing method

[0001] The present invention relates to a printing device and a printing method.

[0002] Printing devices include a conveying member that conveys a print medium onto which ink is to be applied. In this type of printing device, ink that has passed through the print medium may adhere to the surface of the conveying member. Therefore, it is necessary to remove ink and other deposits from the conveying member. For example, Patent Document 1 (JP-A-2005-102626) discloses a printing device that includes a structure for removing deposits from the conveying member, which includes a cleaning tank that stores cleaning liquid and a brush roller that is immersed in the cleaning liquid and rotatably contacts the conveying member (conveyor belt).

[0003] Patent No. 6601241

[0004] A printing device according to one aspect of the present invention includes a transport member capable of transporting a print medium, an ink unit capable of depositing a pigment ink containing a pigment onto the print medium on the transport member, a treatment liquid unit capable of depositing a treatment liquid containing a component capable of forming an aggregate with the pigment onto the print medium on the transport member, a liquid tank unit having a liquid tank capable of storing a liquid and a transfer member capable of sending the pigment and the component present on the transport member to the liquid tank, and a recovery unit capable of recovering the aggregate. The printing device according to this aspect of the present invention makes it possible to accurately or efficiently remove deposits from the transport member.

[0005] A printing method according to another aspect of the present invention includes a transport step of transporting a print medium by a transport member, an ink application step of applying a pigment ink containing a pigment to the print medium on the transport member, a treatment liquid application step of applying a treatment liquid containing a component capable of forming an aggregate with the pigment to the print medium on the transport member, a transfer step of sending the pigment and the component present on the transport member to a liquid tank containing a liquid, and a recovery step of recovering the aggregate contained in the liquid stored in the liquid tank. This printing method according to another aspect of the present invention makes it possible to accurately or efficiently remove deposits from the transport member.

[0006] Fig. 1 is a front view of a printing apparatus according to an embodiment of the present invention. Fig. 2 is a cross-sectional view of the printing apparatus taken along line II-II in Fig. 1. Fig. 3A is a flowchart showing the flow of an image forming process in a printing method. Fig. 3B is a flowchart showing the flow of a transport process and a collection process in the printing method.

[0007] In the printing device of the prior art described above, the cleaning liquid stored in the cleaning tank contains pigment particles, which are the coloring material contained in the ink, in response to the cleaning of the transport member by the brush roller. If the brush roller, immersed in the cleaning liquid containing such pigment particles, comes into contact with the transport member, there is a risk that the pigment particles in the cleaning liquid will re-adhere to the transport member via the brush roller. This poses a problem in that it is not possible to accurately or efficiently remove deposits from the transport member.

[0008] Therefore, there is a demand for a printing apparatus and a printing method that can accurately and efficiently remove the deposits on the conveying member.

[0009] A printing apparatus and a printing method according to an embodiment of the present invention will be described below with reference to the drawings. Note that directional relationships will be described below using XY Cartesian coordinates that are orthogonal to each other on a horizontal plane. The vertical direction perpendicular to the X and Y directions is defined as the Z direction.

[0010] The printing device 1 shown in FIGS. 1 and 2 is an apparatus equipped with an ink unit capable of applying ink to a medium M, which is a wide and long print medium. The printing device 1 prints an image by applying ink to the medium M using the ink unit. Examples of the printing device 1 include a screen printing device and an inkjet device. When the printing device 1 is a screen printing device, the ink unit includes a screen plate having multiple openings and a squeegee. In this case, the ink unit moves the ink along the screen plate in accordance with the movement of the squeegee, thereby applying the ink to the medium M through the openings in the screen plate. On the other hand, when the printing device 1 is an inkjet device, the ink unit ejects ink onto the medium M, thereby applying the ink to the medium M. The following describes in detail the case where the printing device 1 is an inkjet device.

[0011] The inkjet printing device 1 is suitable for digital textile printing, which prints images such as letters and patterns on a medium M, which is a fabric member made of a cloth material such as a woven fabric or a knitted fabric. Of course, the printing device 1 can also be used to print various images on printing media such as paper sheets or resin sheets.

[0012] The printing apparatus 1 includes a device frame 2, a transport unit 3, a printing unit 4, a liquid tank unit 5, a circulation unit 6, and a recovery unit 7. The device frame 2 forms the framework of the printing apparatus 1. In the printing apparatus 1, the transport unit 3, the printing unit 4, the liquid tank unit 5, the circulation unit 6, and the recovery unit 7 are incorporated into the device frame 2.

[0013] The transport unit 3 is a unit for transporting the medium M in the Y direction. The transport unit 3 has a transport member 31, a first transport roller 32, and a second transport roller 33.

[0014] The transport member 31 is a member capable of performing a transport operation to transport the media M. In this embodiment, the transport member 31 is an endless belt that has a width in the X direction and extends in the Y direction. The transport member 31, which is an endless belt, is capable of circular movement as a transport operation. By circularly moving along the Y direction, the transport member 31 can transport the media M, which is in close contact with an upward-facing area on the outer surface of the transport member 31, in a transport direction from one side to the other in the Y direction. An adhesive layer made of an adhesive that adheres the media M is formed on the outer surface of the transport member 31 to maintain the close contact state of the media M on the outer surface of the transport member 31.

[0015] The first transport roller 32 is a cylindrical roller extending in the X direction, around which the transport member 31 is wound at the most downstream position of the transport member 31 in the transport direction of the media M. The first transport roller 32 is rotated in response to the circular movement of the transport member 31. The second transport roller 33 is a cylindrical roller extending in the X direction, around which the transport member 31 is wound at the most upstream position of the transport member 31 in the transport direction of the media M. The second transport roller 33 is driven to rotate by a drive motor (not shown), thereby causing the transport member 31 to move in a circular movement. In other words, the transport member 31 can transport the media M in the transport direction along the Y direction by moving in a circular movement in response to the rotational drive of the second transport roller 33.

[0016] The printing unit 4 is a unit for printing an image on the medium M on the transport member 31. The printing unit 4 is a unit in which an inkjet head 42 having an ink head 421, a pretreatment liquid head 422, and a posttreatment liquid head 423 is mounted on a carriage 41. The printing unit 4 is disposed above the transport member 31 in the Z direction. Specifically, the printing unit 4 is disposed so as to face from above an area of ​​the outer surface of the transport member 31, which is an endless belt, that faces upward. The printing device 1 is a so-called serial printer that performs printing processing on the medium M using a serial printing method. In a serial printing method printing device 1, a discharge operation in which various liquids are discharged from the inkjet head 42 while the carriage 41 is moved back and forth in the X direction, which is orthogonal on the horizontal plane to the Y direction, which is the transport direction of the medium M, and a transport operation of the medium M by the transport member 31 are repeatedly performed. Another embodiment of the printing device 1 is a so-called line printer in which the position of the inkjet head 42 is fixed with respect to the medium M transported in the Y direction by the transport member 31.

[0017] A flat carriage guide 21 having a guide rail 211 extending in the X direction is attached to the device frame 2 at a position above the conveying member 31. The carriage 41 is fixed to a timing belt 212 that is attached to the carriage guide 21 so as to be able to move in circles relative to the carriage guide 21. The timing belt 212 is an endless belt that is driven to move in circles in the X direction while attached to the carriage guide 21. As the timing belt 212 moves in circles in the X direction, the carriage 41 is able to move back and forth in the X direction along the carriage guide 21 while being guided by the guide rail 211.

[0018] Each of the ink head 421, pre-treatment liquid head 422, and post-treatment liquid head 423 included in the inkjet head 42 mounted on the carriage 41 can move relative to the media M in the X and Y directions as the media M is transported in the Y direction by the transport member 31 and the carriage 41 moves back and forth in the X direction.

[0019] The carriage 41 is equipped with multiple ink heads 421. Each of the multiple ink heads 421 is an ink unit capable of ejecting pigment ink containing a pigment as a coloring material to deposit ink onto the medium M on the transport member 31. Each of the multiple ink heads 421 includes a number of nozzles that eject ink droplets of the pigment ink using an ejection method such as a piezoelectric method using a piezoelectric element or a thermal method using a heating element, an ink flow path that guides the pigment ink to the nozzles, and a wiring board for controlling the ejection operation of the pigment ink. The multiple ink heads 421 are mounted on the carriage 41 so as to be aligned in two rows in the X direction. Two ink heads 421 that eject pigment ink of the same color are mounted on the carriage 41 so as to be offset from each other in the X and Y directions. In another embodiment, a configuration in which only one ink head 421 is mounted on the carriage 41 is exemplified.

[0020] The pretreatment liquid head 422 is mounted on the carriage 41 so as to be positioned upstream of the ink head 421 in the direction of transport of the medium M by the transport member 31. The pretreatment liquid head 422 is a pretreatment liquid unit that can eject a pretreatment liquid to deposit the pretreatment liquid onto the medium M on the transport member 31 before the pigment ink. The pretreatment liquid head 422 includes a number of nozzles that eject the pretreatment liquid using an ejection method such as a piezoelectric method using a piezoelectric element or a thermal method using a heating element, a pretreatment liquid flow path that guides the pretreatment liquid to the nozzles, and a wiring board for controlling the ejection operation of the pretreatment liquid. The pretreatment liquid is a treatment liquid that comes into contact with the pigment ink in a non-dried state on the medium M and is a non-color-forming treatment liquid that does not develop color even when it is attached to the medium M. Note that the pretreatment liquid unit that deposits the pretreatment liquid onto the medium M on the transport member 31 is not limited to a head structure such as the pretreatment liquid head 422, and may have a spray-type structure that sprays the pretreatment liquid.

[0021] The posttreatment liquid head 423 is mounted on the carriage 41 so as to be positioned downstream of the ink head 421 in the direction of transport of the medium M by the transport member 31. The posttreatment liquid head 423 is a posttreatment liquid unit that ejects posttreatment liquid to apply the posttreatment liquid to the medium M on the transport member 31 after the pigment ink. The posttreatment liquid head 423 includes a number of nozzles that eject the posttreatment liquid using an ejection method such as a piezo method using a piezo element or a thermal method using a heating element, a posttreatment liquid flow path that guides the posttreatment liquid to the nozzles, and a wiring board for controlling the ejection operation of the posttreatment liquid. The posttreatment liquid is a treatment liquid that comes into contact with the pigment ink in a non-dried state on the medium M and is a non-color-forming treatment liquid that does not develop color even when attached to the medium M. The posttreatment liquid has the function of improving the fixation of the pigment ink on the medium M. A treatment liquid containing silicone oil or the like can be used as such a posttreatment liquid. The silicone oil is stably dispersed in the posttreatment liquid. The post-processing liquid unit that applies the post-processing liquid to the media M on the transport member 31 is not limited to a head structure such as the post-processing liquid head 423, and may have a spray-type structure that sprays the post-processing liquid.

[0022] In the printing unit 4, a liquid ejection operation is performed in which a pretreatment liquid is ejected from the pretreatment liquid head 422, a pigment ink is ejected from the ink head 421, and, if necessary, a posttreatment liquid is ejected from the posttreatment liquid head 423 onto the medium M on the transport member 31. This causes an image to be printed on the medium M. That is, after the pretreatment liquid ejected from the pretreatment liquid head 422 adheres to the medium M on the transport member 31, the pigment ink ejected from the ink head 421 adheres thereto, and then, if necessary, the posttreatment liquid ejected from the posttreatment liquid head 423 adheres thereto.

[0023] The pretreatment liquid ejected from the pretreatment liquid head 422 is a treatment liquid containing water or an aqueous solvent consisting of water and an organic solvent, and an aggregate-forming component capable of forming aggregates with the pigment. Examples of organic solvents that the pretreatment liquid can contain include glycols, alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, ketones, esters, ethers, and vegetable oils. The aggregate-forming component is soluble in the aqueous solvent. Examples of the aggregate-forming component include ionic resins with different ionic properties from the pigment contained in the pigment ink. Examples of ionic resins include positively charged cationic resins. Examples of cationic resins include ammonium-containing resins, amine-containing resins, polyallylamine, polyvinylamine, polyimine, polyvinylpyrrolidone, polyethyleneimine, polyvinylpyridine, aminoacetalized polyvinyl alcohol, ionene polymers, polyvinylimidazole, polyvinylbenzylphosphonium, polyalkylallylammonium, polyamidine, and polyamine sulfone. In the pretreatment liquid, the aggregate-forming component reacts with the pigment contained in the pigment ink to aggregate, thereby ensuring excellent color development.

[0024] The pigment ink ejected from the ink head 421 contains an aqueous medium, a pigment, and a binder resin. The aqueous medium is a medium whose main component is water. Specific examples of aqueous media include water and a mixture of water and a polar solvent. Examples of polar solvents contained in aqueous media include methanol, ethanol, isopropyl alcohol, butanol, and methyl ethyl ketone. The binder resin exists in a state where it is dispersed in the aqueous medium as resin particles. The resin particles of the binder resin function as a binder that bonds the media M and the pigment. The volume median diameter of the resin particles of the binder resin is, for example, 50 nm or more and 150 nm or less. Examples of binder resins include urethane resin, (meth)acrylic resin, styrene-(meth)acrylic resin, styrene-maleic acid copolymer, vinylnaphthalene-(meth)acrylic acid copolymer, and vinylnaphthalene-maleic acid copolymer. The pigment can be a dispersible pigment that exists dispersed in the aqueous medium as pigment particles. To obtain a pigment ink with excellent image density, hue, and color stability, the volume median diameter of the pigment is, for example, 50 nm or more and 150 nm or less. The pigment may be an anionic pigment. Examples of anionic pigments include pigments having anionic groups such as a carboxyl group, a sulfonic acid group, a phosphate group, a phosphonic acid group, a phenylsulfonic acid group, and a phenylcarboxyl group. The anionic pigment undergoes electrical reaction and aggregation on the medium M with a cationic resin, which serves as an aggregate-forming component contained in the pretreatment liquid ejected from the pretreatment liquid head 422. This can prevent the binder resin contained in the pigment ink from penetrating into the medium M. This can reduce the binder resin's penetration into gaps between fibers and bonding the fibers together when the medium M is a fabric material. This can improve the texture, such as the feel of the fabric material.

[0025] In the printing device 1, at least the pigment ink and pretreatment liquid that pass through the medium M during the liquid ejection operation onto the medium M by the printing unit 4, and if the medium M is a fabric material, fibers that have fallen off the fabric material, etc., may adhere to the transport member 31. The pigment ink, pretreatment liquid, etc. that are present on the transport member 31 may cause the medium M to become soiled, reducing the printing quality of the medium M. For this reason, it is necessary to remove the pigment ink, pretreatment liquid, etc. that are present on the transport member 31.

[0026] The liquid tank unit 5 is a unit for removing pigment ink, pretreatment liquid, and the like present on the transport member 31 from the transport member 31. The liquid tank unit 5 is disposed below the transport member 31 in the Z direction. Specifically, the liquid tank unit 5 is disposed below a portion of the transport member 31 that is wound around the first transport roller 32, so as to face from below a downward-facing area on the outer surface of the transport member 31, which is made of an endless belt. A slide rail 22 extending in the Y direction is attached to the device frame 2 below the transport member 31. The liquid tank unit 5 is supported by the slide rail 22 so as to be slidable in the Y direction along the slide rail 22. This allows the liquid tank unit 5 to slide between a reference position below the transport member 31 and a drawn-out position drawn outward in the Y direction relative to the device frame 2. When the liquid tank unit 5 is disposed in the reference position, an operation for removing pigment ink, pretreatment liquid, and the like present on the transport member 31 is performed, and when the liquid tank unit 5 is disposed in the drawn-out position, maintenance work on the liquid tank unit 5 is performed.

[0027] The liquid tank unit 5 has a liquid tank 51 , a transfer member 52 , and a blade 53 .

[0028] The liquid tank 51 is disposed below the conveying member 31 and is capable of storing the liquid L. The liquid L is, for example, water. The liquid tank 51 has a flat bottom wall 511 extending in the X and Y directions and having a first opening 5111 and a second opening 5112 formed therein, and a peripheral wall 512 extending upward from the outer periphery of the bottom wall 511. The liquid tank 51 is a box-shaped tank whose upper side is open so that the bottom wall 511 faces the conveying member 31. The first opening 5111 formed in the bottom wall 511 of the liquid tank 51 is connected to an upstream flow path member 62 in the circulation unit 6 (described later), and the second opening 5112 is connected to a downstream flow path member 63 in the circulation unit 6.

[0029] A float sensor 54 is provided in the liquid tank 51. The float sensor 54 is a sensor for detecting the height position of the liquid level LS of the liquid L stored in the liquid tank 51 from the bottom wall 511. The liquid tank 51 is capable of storing the liquid L so that the liquid level LS of the liquid L is located in a range between a preset upper limit height position P1 and a preset lower limit height position P2.

[0030] Furthermore, a water supply path 511A and a drainage path 511B are provided on the bottom wall 511 of the liquid tank 51. The water supply path 511A forms a path for supplying water as the liquid L to the liquid tank 51. The liquid L is supplied to the liquid tank 51 through the water supply path 511A. The drainage path 511B is provided with, for example, a cock and forms a path for draining the liquid L stored in the liquid tank 51 to the outside of the apparatus. For example, when maintenance work on the liquid tank unit 5 is performed, the liquid tank unit 5 is slid along the slide rails 22 relative to the apparatus frame 2 to the pulled-out position, and the cock of the drainage path 511B is opened, causing the liquid L stored in the liquid tank 51 to drain to the outside of the apparatus via the drainage path 511B.

[0031] The transfer member 52 is a member capable of sending the pigment ink, pretreatment liquid, etc. present on the transport member 31 to the liquid tank 51. In this embodiment, the transfer member 52 is attached to the liquid tank 51 and is capable of sending the pigment ink, pretreatment liquid, etc. present on the transport member 31 to the liquid tank 51 while using the liquid L stored in the liquid tank 51. In the example shown in FIG. 2 , two transfer members 52 are attached to the liquid tank 51. The transfer member 52 has a cylindrical shaft portion 521 extending in the X direction and brush portions 522 extending radially from the outer circumferential surface of the shaft portion 521. The shaft portion 521 is rotatably supported by the peripheral wall 512 of the liquid tank 51. The brush portion 522 of the transfer member 52 is partially immersed in the liquid L stored in the liquid tank 51 and abuts against a downward-facing area on the outer surface of the transport member 31. In this state, the brush portion 522 rotates around the shaft portion 521 in accordance with the rotation of the shaft portion 521, thereby being able to send the pigment ink, pretreatment liquid, etc. present on the transport member 31 to the liquid tank 51 while using the liquid L stored in the liquid tank 51. The transfer member 52 is able to remove the pigment ink, pretreatment liquid, etc. present on the transport member 31 from the transport member 31 by sending them to the liquid tank 51, thereby cleaning the transport member 31.

[0032] The blades 53 are plate-shaped rubber members extending in the X direction and attached to the peripheral wall 512 of the liquid tank 51 so as to abut against a downward-facing area on the outer surface of the conveying member 31. In this embodiment, two blades 53 are attached to the peripheral wall 512. The blades 53 can remove the liquid L remaining on the conveying member 31 after the transfer member 52 cleans the conveying member 31, in accordance with the circular movement of the conveying member 31.

[0033] In the printing device 1, deposits on the transport member 31, such as the pigment ink, pretreatment liquid, and fibers derived from the medium M, are sent to the liquid tank 51 by the transfer member 52. In this case, the liquid L stored in the liquid tank 51 contains aggregates A in addition to fibers derived from the medium M. Aggregates A are generated when the pigment ink and the pretreatment liquid come into contact on the transport member 31 or in the liquid L, causing a reaction and aggregation between the pigment contained in the pigment ink and the aggregate-forming components contained in the pretreatment liquid. Aggregates A are generated by contact between the pigment ink used to form an image on the medium M and the pretreatment liquid, even if an aggregating agent or the like is not added to the liquid L.

[0034] When the transfer member 52 immersed in the liquid L containing fibers and aggregates A derived from the media M comes into contact with the transport member 31, the fibers and aggregates A in the liquid L may re-adhere to the transport member 31, making it impossible to accurately or efficiently remove the deposits on the transport member 31. Therefore, the printing device 1 is provided with a circulation unit 6 and a recovery unit 7.

[0035] Recovery unit 7 is a unit capable of recovering flocculant A. Recovery unit 7 is incorporated into liquid tank unit 5 or into circulation unit 6. When recovery unit 7 is incorporated into liquid tank unit 5, installation of circulation unit 6 may be omitted. In this case, recovery unit 7 is installed in liquid tank 51 of liquid tank unit 5, and is capable of recovering flocculant A contained in liquid L stored in liquid tank 51. In the example shown in FIGS. 1 and 2 , recovery unit 7 is incorporated into circulation unit 6.

[0036] The circulation unit 6 is disposed below the liquid tank unit 5 in the Z direction. The circulation unit 6 is a unit capable of circulating the liquid L through the liquid tank 51. The circulation unit 6 has a circulation flow path member 6A and a pump 6B.

[0037] The circulation flow path member 6A is a member that forms a flow path through which the liquid L stored in the liquid tank 51 circulates via the liquid tank 51. The circulation flow path member 6A includes an intermediary flow path member 61, an upstream flow path member 62, and a downstream flow path member 63. The upstream flow path member 62 forms a flow path on the upstream side in the flow direction of the liquid L in the circulation flow path member 6A. The downstream flow path member 63 forms a flow path on the downstream side in the flow direction of the liquid L in the circulation flow path member 6A. The intermediary flow path member 61 forms a flow path that relays the flow of the liquid L between the upstream flow path member 62 and the downstream flow path member 63.

[0038] The relay flow path member 61 is a cylindrical member extending in the X direction and supported by a support bar 221 fixed to the slide rail 22 on which the liquid tank unit 5 is supported. The relay flow path member 61 is connected to at least the recovery unit 7 and forms a flow path through which the liquid L flows via the recovery unit 7. The upstream flow path member 62 connects one end of the relay flow path member 61 in the X direction to the liquid tank 51 and forms a flow path through which the liquid L stored in the liquid tank 51 flows to the relay flow path member 61. The downstream flow path member 63 connects the other end of the relay flow path member 61 opposite to the one end in the X direction to the liquid tank 51 and forms a flow path through which the liquid L that flows from one end to the other end of the relay flow path member 61 and passes through the relay flow path member 61 flows to the liquid tank 51. In the circulation unit 6, the liquid L can be circulated through the liquid tank 51 by a circulation flow path member 6A including the relay flow path member 61, the upstream flow path member 62, and the downstream flow path member 63. The liquid L stored in the liquid tank 51 flows through the upstream flow path member 62, then flows through the relay flow path member 61 in a flow direction D1 from one end of the relay flow path member 61 to the other end thereof, and then flows through the downstream flow path member 63 and is returned to the liquid tank 51. In this way, the liquid L stored in the liquid tank 51 is circulated by flowing through the upstream flow path member 62, relay flow path member 61, and downstream flow path member 63 in this order.

[0039] The relay flow path member 61 is connected to a pump 6B, a strainer 70 and a recovery unit 7.

[0040] The pump 6B is a circulation pump for sending the liquid L from the upstream flow path member 62 to the downstream flow path member 63. By driving the pump 6B, the liquid L stored in the liquid tank 51 is circulated via the upstream flow path member 62, the relay flow path member 61, and the downstream flow path member 63.

[0041] The strainer 70 is connected to the relay flow path member 61 at a position upstream of the pump 6B in the flow direction D1. The strainer 70 is a filter capable of filtering out fibers derived from the media M contained in the liquid L. The filtration accuracy of the strainer 70 is, for example, approximately 180 μm. Therefore, although the strainer 70 is capable of filtering out fibers in the liquid L, it is unable to separate aggregates A, which have a volume median diameter smaller than the filtration accuracy. The volume median diameter of the aggregates A is larger than the volume median diameter of pigment particles and smaller than the fibers derived from the media M. The volume median diameter of the aggregates A has a wide distribution depending on the degree of reactive aggregation between the pigment in the pigment ink and the aggregate-forming components in the pretreatment liquid, and is, for example, 20 μm or more and 50 μm or less.

[0042] The recovery unit 7 is connected to the relay flow path member 61 at a position downstream of the pump 6B in the flow direction D1. The recovery unit 7 is capable of recovering the aggregate A contained in the liquid L. Examples of such a recovery unit 7 include a filtration filter that recovers the aggregate A from the liquid L by filtering and separating it, and a centrifuge that recovers the aggregate A from the liquid L by centrifuging it.

[0043] In this embodiment, the recovery unit 7 includes a first filtration filter 71 connected to the relay flow path member 61 at a first position in a region downstream of the pump 6B in the flow direction D1, and a second filtration filter 72 connected to the relay flow path member 61 at a second position closer to the downstream flow path member 63 (downstream) than the first position. The first filtration filter 71 and the second filtration filter 72 may be, for example, a deep filtration type thread-wound filter having a resin thread wound around a core. The first filtration accuracy of the first filtration filter 71 is set to, for example, approximately 50 μm, near the upper limit of the volume median diameter distribution of the aggregates A to be recovered. The second filtration accuracy of the second filtration filter 72 is higher than the first filtration accuracy and is set to, for example, approximately 20 μm, near the lower limit of the volume median diameter distribution of the aggregates A to be recovered. The recovery unit 7, which has two first and second filtration filters 71 and 72 with different filtration accuracies, makes it possible to accurately or efficiently recover the agglomerates A contained in the liquid L, and also reduces clogging of the filter compared to when using a single filtration filter.

[0044] As described above, in the printing device 1 according to this embodiment, while the liquid L stored in the liquid tank 51 is circulated through the liquid tank 51 by the circulation unit 6, fibers and the like derived from the media M contained in the liquid L are filtered and separated by the strainer 70, and the aggregates A contained in the liquid L are collected by the collection unit 7. This makes it possible to reduce the amount of fibers and aggregates A present in the liquid L stored in the liquid tank 51, thereby making it possible to suppress a decrease in the ability of the liquid L to remove deposits on the conveying member 31.

[0045] In particular, if the pigment contained in the pigment ink is contained in the liquid L in the form of pigment particles, as previously mentioned, the pigment particles are minute particles with very small particle diameters, making it difficult to separate the pigment particles from the liquid L. One possible method for separating the pigment particles from the liquid L is to introduce the liquid L containing the pigment particles into a specified tank and add a flocculant or the like to the tank to flocculate the pigment particles. However, in this case, a separate tank and flow path for adding the flocculant would need to be installed, necessitating a major design change to the printing device 1.

[0046] In contrast, the printing device 1 according to this embodiment utilizes the reactive aggregation of the pigment in the pigment ink used in image formation on the medium M and the aggregate-forming component in the pretreatment liquid, and recovers the aggregate A produced by this reactive aggregation using the recovery unit 7. The recovery unit 7 can recover the aggregate A more accurately and efficiently than when the aggregate A is recovered in the form of pigment particles.

[0047] 1 , a valve 64 is connected to one end of the relay flow path member 61 at the most upstream position in the flow direction D1 of the liquid L. The valve 64 is a valve for opening and closing the flow path of the relay flow path member 61. The valve 64 is opened while the liquid L is circulating, and is closed when maintenance work on the strainer 70 or replacement work on the recovery unit 7 is performed.

[0048] Furthermore, in the relay flow path member 61, a first pressure sensor 81 is connected near the strainer 70, a second pressure sensor 82 is connected near the first filtration filter 71, and a third pressure sensor 83 is connected near the second filtration filter 72. The first pressure sensor 81 is a sensor that detects the pressure of the liquid L flowing into the strainer 70. The clogging state of the strainer 70 can be determined based on the detection result of the first pressure sensor 81. The second pressure sensor 82 is a sensor that detects the pressure of the liquid L flowing into the first filtration filter 71. The clogging state of the first filtration filter 71 can be determined based on the detection result of the second pressure sensor 82. The third pressure sensor 83 is a sensor that detects the pressure of the liquid L flowing into the second filtration filter 72. The clogging state of the second filtration filter 72 can be determined based on the detection result of the third pressure sensor 83.

[0049] 1 and 2 , the upstream flow path member 62 has a first upstream connection portion 621 connected to the liquid tank 51 and a second upstream connection portion 622 connected to the relay flow path member 61. The second upstream connection portion 622 is connected to one end of the relay flow path member 61 that is furthest upstream in the flow direction D1 of the liquid L. The first upstream connection portion 621 corresponds to the most upstream end of the circulation flow path member 6A that is located furthest upstream in the flow direction of the liquid L. The first upstream connection portion 621 has an inlet 6211 through which the liquid L stored in the liquid tank 51 flows, and is connected to the bottom wall 511 so that the inlet 6211 communicates with a first opening 5111 in the bottom wall 511 of the liquid tank 51. This allows the liquid L, including fibers and aggregates A that have settled on the bottom wall 511, that flows from the liquid tank 51 into the upstream flow path member 62 through the first upstream connection portion 621 to flow to the relay flow path member 61 through the second upstream connection portion 622. Therefore, fibers and aggregates A that would settle on the bottom wall 511 in the liquid L in the liquid tank 51 can be collected by the strainer 70 and the collection unit 7 connected to the relay flow path member 61.

[0050] The downstream flow path member 63 also has a first downstream connection portion 631 connected to the relay flow path member 61 and a second downstream connection portion 632 connected to the liquid tank 51. The first downstream connection portion 631 is connected to the other end of the relay flow path member 61 at the most downstream position in the flow direction D1 of the liquid L. The second downstream connection portion 632 corresponds to the most downstream end of the circulation flow path member 6A located most downstream in the flow direction of the liquid L. The second downstream connection portion 632 has an outlet 6321 through which the liquid L having flowed through the circulation flow path member 6A flows into the liquid tank 51. The second downstream connection portion 632 is connected to the bottom wall 511 in a state where it is inserted through a second opening 5112 formed in the bottom wall 511 so that the outlet 6321 is located above an upper limit height position P1 of the liquid level LS of the liquid L stored in the liquid tank 51 from the bottom wall 511. This allows the liquid L that has passed through the relay flow path member 61 to be supplied to the liquid tank 51 through the first downstream connection part 631 and the second downstream connection part 632. Note that the second downstream connection part 632 is not limited to being connected to the bottom wall 511, and may be connected to the peripheral wall 512, as long as the outlet 6321 is located above the upper limit height position P1 of the liquid level LS of the liquid L stored in the liquid tank 51.

[0051] 1, the printing device 1 further includes a display unit 91 and a control unit 92. The display unit 91 is a display capable of displaying various types of information. The display of information on the display unit 91 is controlled by the control unit 92.

[0052] The control unit 92 is a personal computer having a CPU (Central Processing Unit), a storage area such as a HDD (Hard Disk Drive) or flash memory for storing processing programs, and a RAM (Random Access Memory) used as a CPU work area. The control unit 92 performs an image formation process on the medium M based on control of the transport unit 3 and the printing unit 4 by the CPU executing the processing programs stored in the HDD or flash memory. The control unit 92 also performs a transfer process to transfer deposits on the transport member 31 to the liquid tank 51 based on control of the liquid tank unit 5. Furthermore, the control unit 92 also performs a recovery process to recover aggregates A while circulating the liquid L through the liquid tank 51 based on control of the circulation unit 6. The control unit 92 performs the image formation process, transfer process, and recovery process to execute each step of the printing method using the printing device 1. The process of each step of the printing method executed by the control unit 92 will be described in detail with reference to FIGS. 3A and 3B .

[0053] First, the image forming process performed by the control unit 92 will be described with reference to FIG. 3A . Based on image data of an image to be formed on the medium M, the control unit 92 repeatedly performs a transport step a1 in which the transport member 31 of the transport unit 3 transports the medium M, and a printing step using the inkjet head 42 on the medium M on the transport member 31. The printing step using the inkjet head 42 includes a pretreatment liquid application step a2 in which the pretreatment liquid is applied to the medium M in response to the ejection of pretreatment liquid from the pretreatment liquid head 422, an ink application step a3 in which the pigment ink is applied to the medium M in response to the ejection of pigment ink from the ink head 421, and a posttreatment liquid application step a4 in which the posttreatment liquid is applied to the medium M in response to the ejection of posttreatment liquid from the posttreatment liquid head 423. The transport step a1, the pretreatment liquid application step a2, the ink application step a3, and the posttreatment liquid application step a4 are repeatedly performed, thereby forming an image on the medium M on the transport member 31.

[0054] In the media M on the transport member 31, the aggregate-forming component contained in the pretreatment liquid reacts with and aggregates the pigment contained in the pigment ink, thereby preventing the binder resin contained in the pigment ink from penetrating into the media M. This reduces the likelihood of the binder resin binding fibers together when the media M is a fabric material, thereby improving the texture, such as the feel of the fabric material. Furthermore, the adhesion of the posttreatment liquid to the media M on the transport member 31 improves the fixability of the pigment ink on the media M.

[0055] 3B, the transfer process and the recovery process performed by the control unit 92 will be described. The control unit 92 performs the transfer process and the recovery process while moving the conveying member 31 in a circular motion during or after the image forming process.

[0056] The control unit 92 performs a supply step b1 in which the liquid L is supplied to the liquid tank 51 through the water supply path 511A based on the detection result of the float sensor 54. Specifically, the control unit 92 supplies the liquid L to the liquid tank 51 through the water supply path 511A based on the detection result of the float sensor 54 so that the liquid level LS of the liquid L in the liquid tank 51 is located in the range between the upper limit height position P1 and the lower limit height position P2. As a result, the liquid L is stored in the liquid tank 51 so that a portion of the brush portion 522 of the transfer member 52 attached to the liquid tank 51 is immersed in the liquid L.

[0057] With a predetermined amount of liquid L stored in the liquid tank 51, the control unit 92 performs the processes of the transfer step b2 and the circulation step b3.

[0058] In the transfer step b2, the control unit 92 rotationally drives the shaft portion 521 of the transfer member 52, thereby rotating the brush portion 522 that is immersed in the liquid tank 51 and abuts against the transport member 31, thereby sending the pigment ink, the pretreatment liquid, and any deposits on the transport member 31, such as fibers derived from the medium M, to the liquid tank 51. Therefore, the liquid L stored in the liquid tank 51 contains fibers derived from the medium M and aggregates A. The aggregates A are generated when the pigment ink and the pretreatment liquid come into contact on the transport member 31 or in the liquid L, causing a reaction and aggregation between the pigment contained in the pigment ink and the aggregate-forming component contained in the pretreatment liquid.

[0059] In the circulation step b3, the control unit 92 drives the pump 6B to circulate the liquid L stored in the liquid tank 51 through the circulation flow path member 6A connected to the liquid tank 51. In the circulation step b3, while the liquid L is circulating through the circulation flow path member 6A, fibers and the like derived from the media M contained in the liquid L are filtered and separated by the strainer 70 connected to the relay flow path member 61, and further, a recovery step b4 is performed in which the aggregate A is recovered by the recovery unit 7 connected to the relay flow path member 61. This makes it possible to reduce the amount of fibers and aggregate A present in the liquid L stored in the liquid tank 51, thereby making it possible to suppress a decrease in the ability of the liquid L to remove deposits on the transport member 31.

[0060] Furthermore, the control unit 92 may monitor the detection results of the first pressure sensor 681, the second pressure sensor 682, and the third pressure sensor 683 in the circulation step b3.

[0061] When the detection result of the first pressure sensor 681 exceeds a predetermined threshold, the control unit 92 causes the display unit 91 to display maintenance request information indicating a request for maintenance work on the strainer 70. The operator can perform maintenance work to unclog the strainer 70 by checking the maintenance request information displayed on the display unit 91. When the detection result of the second pressure sensor 682 exceeds a predetermined threshold, the control unit 92 causes the display unit 91 to display first replacement request information indicating a request for replacement work on the first filtration filter 71. The operator can perform replacement work on the first filtration filter 71 due to clogging by checking the first replacement request information displayed on the display unit 91. Similarly, when the detection result of the third pressure sensor 683 exceeds a predetermined threshold, the control unit 92 causes the display unit 91 to display second replacement request information indicating a request for replacement work on the second filtration filter 72. By checking the second replacement request information displayed on the display unit 91, the operator can replace the second filtration filter 72 due to clogging of the second filtration filter 72.

[0062] Furthermore, control unit 92 may periodically display unit maintenance information on display unit 91, which indicates information requesting the performance of maintenance work on tank unit 5. The operator can perform maintenance work on tank unit 5 by checking the unit maintenance information displayed on display unit 91. During maintenance work on tank unit 5, the operator, for example, slides tank unit 5 along slide rails 22 to pull out tank unit 5 to the pulled-out position. With tank unit 5 pulled out to the pulled-out position, the operator opens the cock of drainage path 511B to allow liquid L stored in tank 51 to flow out of the apparatus through drainage path 511B. Because fibers, aggregates A, and the like in liquid L are collected in strainer 70 and collection unit 7, liquid L flowing out of the apparatus through drainage path 511B does not contain fibers, aggregates A, and the like.

[0063] With the liquid L flowing out of the liquid tank 51 , the operator can perform maintenance work such as cleaning the liquid tank 51 and the transfer member 52 of the liquid tank unit 5 .

[0064] REFERENCE SIGNS LIST 1 Printing device 3 Transport unit 31 Transport member 4 Printing unit 42 Inkjet head 421 Ink head (ink unit) 422 Pretreatment liquid head (treatment liquid unit) 5 Liquid tank unit 51 Liquid tank 511 Bottom wall 512 Peripheral wall 52 Transfer member 6 Circulation unit 6A Circulation flow path member 61 Relay flow path member 62 Upstream flow path member 63 Downstream flow path member 7 Recovery unit 71 First filtration filter 72 Second filtration filter

Claims

1. a conveying member capable of conveying a print medium; an ink unit capable of depositing a pigment ink containing a pigment onto the print medium on the transport member; a treatment liquid unit capable of applying a treatment liquid containing a component capable of forming an aggregate with the pigment to the print medium on the transport member; a liquid tank unit having a liquid tank capable of storing a liquid and a transfer member capable of sending the pigment and the component present on the conveying member to the liquid tank; a recovery unit capable of recovering the agglomerate; The printing device, wherein the liquid tank unit is movable between a reference position below the transport member and a drawn-out position where it is drawn out downstream in a transport direction of the print medium relative to the transport member.

2. A conveying member capable of conveying a print medium; an ink unit capable of depositing a pigment ink containing a pigment onto the print medium on the transport member; a treatment liquid unit capable of applying a treatment liquid containing a component capable of forming an aggregate with the pigment to the print medium on the transport member; a liquid tank unit having a liquid tank capable of storing a liquid and a transfer member capable of sending the pigment and the component present on the conveying member to the liquid tank; a circulation unit having a circulation flow path member that forms a flow path through which the liquid stored in the liquid tank circulates via the liquid tank; a recovery unit connected to the circulation flow path member and capable of recovering the aggregate contained in the liquid flowing through the circulation flow path member; a pressure sensor connected to the circulation flow path member and capable of detecting the pressure of the liquid flowing into the recovery unit.

3. The recovery unit comprises: a first filtration filter connected to a first position of the circulation flow path member and having a first filtration accuracy; 3. The printing device according to claim 2, further comprising: a second filtration filter connected to the circulation flow path member at a second position downstream of the first position in the direction of flow of the liquid, the second filtration filter having a second filtration accuracy higher than the first filtration accuracy.

4. A conveying member capable of conveying a print medium; an ink unit capable of depositing a pigment ink containing a pigment onto the print medium on the transport member; a treatment liquid unit capable of applying a treatment liquid containing a component capable of forming an aggregate with the pigment to the print medium on the transport member; a liquid tank unit having a liquid tank capable of storing a liquid and a transfer member capable of sending the pigment and the component present on the conveying member to the liquid tank; a circulation unit having a circulation flow path member that forms a flow path through which the liquid stored in the liquid tank circulates via the liquid tank; a collection unit connected to the circulation flow path member and capable of collecting the aggregate contained in the liquid flowing through the circulation flow path member, the liquid tank is disposed below the conveying member, has a bottom wall and a peripheral wall extending upward from an outer peripheral edge of the bottom wall, and is a tank whose upper side is open so that the bottom wall faces the conveying member; an upstream end portion of the circulation flow path member located at the upstream end in a flow direction of the liquid has an inlet through which the liquid stored in the liquid tank flows, and the inlet is connected to the bottom wall so as to communicate with the inside of the liquid tank; a most downstream end portion of the circulation flow path member that is located most downstream in the flow direction of the liquid has an outlet through which the liquid that has flowed through the circulation flow path member flows out into the liquid tank, and is connected to the bottom wall or the peripheral wall so that the outlet is located above an upper limit height position of the liquid level of the liquid stored in the liquid tank from the bottom wall.

5. the transfer member is rotatably supported in the liquid tank so as to be partially immersed in the liquid stored in the liquid tank and to be in contact with the conveying member, and is capable of conveying the pigment and the component present on the conveying member to the liquid tank by rotation while using the liquid; The printing apparatus according to claim 1 , wherein the recovery unit is capable of recovering the aggregate contained in the liquid stored in the liquid tank.

6. The printing device according to claim 1 , wherein the printing medium is a fabric member made of fabric.

7. the pigment contained in the pigment ink is an anionic pigment, The printing apparatus according to claim 1 , wherein the component contained in the treatment liquid is a cationic resin.

8. a conveying step of conveying the print medium by a conveying member; an ink applying step of applying a pigment ink containing a pigment to the print medium on the transport member; a treatment liquid application step of applying a treatment liquid containing a component capable of forming an aggregate with the pigment to the print medium on the transport member; a transfer step of transferring the pigment and the component present on the conveying member to a liquid tank in which a liquid is stored by a liquid tank unit disposed at a reference position below the conveying member; a recovery step of recovering the aggregate contained in the liquid stored in the liquid tank, a printing method in which maintenance work is performed on the liquid tank unit in a state in which the liquid tank unit is moved from the reference position to a drawn-out position drawn out downstream in a print medium transport direction relative to the transport member;

9. A conveying step of conveying the print medium by a conveying member; an ink applying step of applying a pigment ink containing a pigment to the print medium on the transport member; a treatment liquid application step of applying a treatment liquid containing a component capable of forming an aggregate with the pigment to the print medium on the transport member; a transferring step of transferring the pigment and the component present on the conveying member to a liquid tank containing a liquid; a circulation step of circulating the liquid stored in the liquid tank through a circulation flow path member connected to the liquid tank; a recovery step of recovering the aggregate contained in the liquid flowing through the circulation flow path member by a recovery unit connected to the circulation flow path member, In the circulating step, the recovery unit is replaced in accordance with a detection result of a pressure of the liquid flowing into the recovery unit by a pressure sensor connected to the circulation flow path member.

10. A conveying step of conveying the print medium by a conveying member; an ink applying step of applying a pigment ink containing a pigment to the print medium on the transport member; a treatment liquid application step of applying a treatment liquid containing a component capable of forming an aggregate with the pigment to the print medium on the transport member; a transferring step of transferring the pigment and the component present on the conveying member to a liquid tank containing a liquid; a circulation step of circulating the liquid stored in the liquid tank through a circulation flow path member connected to the liquid tank; a recovery step of recovering the aggregate contained in the liquid flowing through the circulation flow path member, In the circulation process, the liquid stored in the liquid tank is caused to flow into the circulation flow path member from a bottom wall of the liquid tank, and the liquid that has flowed through the circulation flow path member is caused to flow out into the liquid tank from above the liquid surface of the liquid stored in the liquid tank.