Liquid recovery device

Abstract

To provide a liquid recovery device which can reduce time and effort for discarding a waste liquid, without using an additional substance.SOLUTION: A control part performs control to send waste liquid of pretreatment liquid from a pretreatment liquid storage tank 34 to a mixed liquid container 38 by a pump 41, to send the waste liquid of ink in an amount to be aggregated by the waste liquid of the pretreatment liquid sent to the mixed liquid container 38 from an ink storage tank 35 to the mixed liquid container 38 by a pump 43, and to send the waste liquid of the ink excluding the ink sent to the mixed liquid container 38 from the ink storage tank 35 to a waste liquid bottle 39 by a pump 44.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a liquid recovery device for recovering liquid.

Background Art

[0002] In an inkjet printing apparatus, a maintenance operation of the inkjet head is performed to reduce ejection failure of the inkjet head. As a maintenance operation of the inkjet head, for example, a series of operations is known in which, after performing so-called purging in which ink is forcibly discharged from nozzles, the nozzle surface of the inkjet head is wiped with a wiper.

[0003] The ink discharged in the maintenance operation of the inkjet head as described above is collected in a waste liquid bottle as waste liquid and then discarded.

[0004] By the way, some inkjet printing apparatuses eject a pretreatment liquid for aggregating ink before ejecting the ink onto a printing medium.

[0005] In such an inkjet printing apparatus, ink and the pretreatment liquid are discharged in the maintenance operation of the inkjet head. For this reason, waste liquid of the ink and waste liquid of the pretreatment liquid are generated.

[0006] When waste liquid bottles for ink and waste liquid bottles for the pretreatment liquid are provided separately, since the amounts of waste liquid collected in each are different, waste liquid management becomes complicated. Further, since the timings at which the respective waste liquid bottles become full are different, the number of times of discarding the waste liquid stored in the waste liquid bottles increases, and it takes time to discard the waste liquid.

[0007] If the waste liquid of the ink and the waste liquid of the pretreatment liquid are collected in one waste liquid bottle, waste liquid management becomes easier than the case where waste liquid bottles for ink and waste liquid bottles for the pretreatment liquid are provided separately.

[0008] However, if the waste liquid of ink and the waste liquid of the pretreatment liquid are collected in one waste liquid bottle, they will react to generate aggregates. Therefore, even if the waste liquid in the waste liquid bottle is discarded, the aggregates may remain, which may reduce the capacity of the waste liquid bottle. When the capacity of the waste liquid bottle decreases, the frequency of discarding the waste liquid in the waste liquid bottle increases, and it takes time to discard the waste liquid.

[0009] In contrast, Patent Document 1 discloses a technique for suppressing aggregation and thickening of mixed waste liquid by including an anti-aggregation / thickening agent when disposing of two or more kinds of printing liquids that cause aggregation or thickening when mixed.

[0010] By using this technique, even in a configuration where the waste liquid of ink and the waste liquid of the pretreatment liquid are collected in one waste liquid bottle, the decrease in the capacity of the waste liquid bottle due to the remaining aggregates can be suppressed, and the increase in the frequency of discarding the waste liquid in the waste liquid bottle can be suppressed. As a result, the labor of discarding the waste liquid can be reduced.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0012] However, in the technique of Patent Document 1, it is necessary to use an additional substance such as an anti-aggregation / thickening agent.

[0013] The present invention has been made in view of the above, and an object thereof is to provide a liquid recovery device that can reduce the labor of discarding waste liquid without using an additional substance.

Means for Solving the Problems

[0014] In order to achieve the above object, the liquid recovery device of the present invention includes a first container for storing the waste liquid of the first liquid, a waste liquid of the first liquid, and a waste liquid of the second liquid for aggregating the first liquid, which are mixed and stored in a second container, a first liquid delivery unit for delivering the waste liquid of the first liquid to the first container, a second liquid delivery unit for delivering the waste liquid of the second liquid to the second container, a third liquid delivery unit for delivering the waste liquid of the first liquid to the second container, and a control unit for controlling the waste liquid of the second liquid to be delivered to the second container by the second liquid delivery unit, and delivering an amount of the waste liquid of the first liquid within the range of aggregation by the amount of the waste liquid of the second liquid delivered to the second container to the second container by the third liquid delivery unit, and delivering the waste liquid of the first liquid other than that delivered to the second container to the first container by the first liquid delivery unit.

Effect of the Invention

[0015] According to the liquid recovery device of the present invention, the labor of waste liquid disposal can be reduced without using additional substances.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts and components are denoted by the same or equivalent reference numerals throughout the drawings.

[0018] The embodiments described below illustrate devices and the like for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the materials, shapes, structures, arrangements, etc. of each component as those described below. The technical idea of the present invention can be variously modified within the scope of the claims.

[0019] [First Embodiment] FIG. 1 is a block diagram showing a schematic configuration of a printing apparatus provided with a liquid recovery apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a printing unit of the printing apparatus shown in FIG. 1. FIG. 3 is a schematic configuration diagram of a capping unit of the printing apparatus shown in FIG. 1. FIG. 4 is a schematic configuration diagram of a cap portion of the capping unit shown in FIG. 3. In FIG. 2, the direction perpendicular to the paper surface is defined as the vertical direction, and the front surface direction of the paper surface is defined as the upper direction. Also, the front, rear, left, and right of the paper surface in FIG. 2 are defined as the front-rear, left-right directions.

[0020] As shown in FIG. 1, a printing apparatus 1 according to the first embodiment includes a printing unit 2, a conveyance unit 3, a capping unit 4, a wiping unit 5, and a control unit 6. Note that the capping unit 4 and the control unit 6 constitute a liquid recovery apparatus.

[0021] The printing unit 2 performs printing on a cloth, which is a printing medium, by an inkjet method. The printing unit 2 includes a head unit 11 and a rail unit 12.

[0022] Here, examples of the cloth include natural fibers such as cotton, silk, wool, and linen; chemical fibers such as polyester, acrylic, polyurethane, nylon, rayon, cupra, and acetate; or blended fibers thereof. Also, the cloth may be a woven fabric, a knitted fabric, a non-woven fabric, or the like.

[0023] The head unit 11 discharges a pretreatment liquid (corresponding to the second liquid and the treatment liquid) and ink (corresponding to the first liquid) onto the cloth to perform printing. The head unit 11 includes heads 21A to 21F and a head holder 22. Note that the alphabetic subscripts in the symbols such as heads 21A to 21F may be omitted and collectively represented.

[0024] The head 21A discharges the pretreatment liquid onto the fabric. The head 21A has a plurality of nozzles (not shown) that open on the nozzle surface, which is the lower surface thereof, and are arranged along the front-rear direction (sub-scanning direction), and discharges the pretreatment liquid from the nozzles. Details of the pretreatment liquid will be described later.

[0025] The head 21B discharges white ink onto the fabric onto which the pretreatment liquid has been discharged. The head 21B has the same configuration as the head 21A except that the liquid to be discharged is different. The head 21B is arranged behind the head 21A in the front-rear direction (sub-scanning direction). Details of the white ink will be described later.

[0026] The heads 21C to 21F discharge color ink onto the fabric onto which the pretreatment liquid and white ink have been discharged. In the present embodiment, the heads 21C, 21D, 21E, and 21F discharge black, cyan, magenta, and yellow inks, respectively. The heads 21C to 21F have the same configuration as the head 21A except that the liquid to be discharged is different. The heads 21C to 21F are arranged behind the head 21B in the front-rear direction (sub-scanning direction). The heads 21C to 21F are arranged in parallel in the left-right direction (main scanning direction). Details of the color ink will be described later.

[0027] The head holder 22 holds the heads 21A to 21F.

[0028] The rail portion 12 reciprocates the head unit 11 in the left-right direction (main scanning direction).

[0029] The conveyance unit 3 has a support portion (not shown) that supports the fabric, and conveys the fabric supported by the support portion in the conveyance direction (sub-scanning direction) from the front side to the rear side below the head unit 11.

[0030] The capping unit 4 seals the nozzle surfaces of the heads 21A to 21F in order to prevent the nozzles of the heads 21A to 21F from drying during the standby period when the printing apparatus 1 is not performing a printing operation.

[0031] Further, in the maintenance operation of cleaning the heads 21A to 21F, when a purge is performed to discharge the pretreatment liquid from the head 21A and discharge the ink from the heads 21B to 21F, the capping unit 4 seals the nozzle surfaces of the heads 21A to 21F. Also, in the maintenance operation, the capping unit 4 collects the pretreatment liquid and ink discharged from the heads 21A to 21F by the purge as waste liquid.

[0032] The capping unit 4 includes cap parts 31A to 31F, a plate material 32, waste liquid receiving parts 33A to 33F (the waste liquid receiving parts 33C to 31F are not shown), a pretreatment liquid storage tank 34, an ink storage tank 35, liquid amount detection parts 36, 37, a mixed liquid container (corresponding to the second container) 38, a waste liquid bottle (corresponding to the first container) 39, pumps 40 to 44, pretreatment liquid paths 45, 46, ink paths 47 to 49, a stirring part 50, and a water-absorbing polymer input part 51.

[0033] The cap parts 31A to 31F seal the nozzle surfaces of the heads 21A to 21F respectively. The cap parts 31A to 31F are arranged at positions corresponding to the heads 21A to 21F respectively on the plate material 32.

[0034] The cap part 31 includes a base 31a and a capping member 31b formed on the base 31a. The capping member 31b includes a bottom part 31c and a peripheral wall 31d erected on the periphery of the bottom part 31c. Two discharge holes 31e are formed in the bottom part 31c.

[0035] The length of the capping member 31b in the front-rear direction is equal to the length of the head 21 in the front-rear direction. And the peripheral wall 31d of the capping member 31b is formed of a resin such as rubber, and seals the nozzle surface of the head 21 by contacting and adhering to the head 21.

[0036] When the purge of the head 21 is performed, the liquid discharged from the head 21 and dropped from the nozzle surface is received by the capping member 31b and discharged as waste liquid from the discharge hole 31e formed in the bottom portion 31c.

[0037] The plate material 32 is a member that holds the cap portions 31A to 31F and the waste liquid receiving portions 33A to 33F.

[0038] The waste liquid receiving portion 33 receives the waste liquid discharged from the discharge hole 31e of the cap portion 31. The waste liquid receiving portions 33A to 33F are arranged at positions corresponding to the cap portions 31A to 31F, respectively, on the lower surface of the plate material 32.

[0039] The pretreatment liquid storage tank 34 stores the waste liquid of the pretreatment liquid sent from the waste liquid receiving portion 33A. The ink storage tank 35 stores the waste liquid of the ink (white ink and color ink) sent from the waste liquid receiving portions 33B to 33F.

[0040] The liquid amount detection unit 36 detects the amount of the waste liquid of the pretreatment liquid stored in the pretreatment liquid storage tank 34. The liquid amount detection unit 37 detects the amount of the waste liquid of the ink stored in the ink storage tank 35. The liquid amount detection units 36 and 37 are constituted by, for example, sensors that detect the liquid level of the waste liquid.

[0041] The mixed liquid container 38 mixes and stores the waste liquid of the pretreatment liquid sent from the pretreatment liquid storage tank 34 and the waste liquid of the ink sent from the ink storage tank 35. The mixed liquid container 38 is constituted by, for example, a wide-mouth container so that the aggregates formed by the aggregation of the ink with the pretreatment liquid can be easily discarded. Further, the mixed liquid container 38 may be a container such as a pouch that is sealed by a chuck and can be discarded as a whole.

[0042] The waste liquid bottle 39 stores the waste liquid of the ink sent from the ink storage tank 35.

[0043] The pump 40 pumps the waste liquid of the pretreatment liquid from the waste liquid receiving part 33A to the pretreatment liquid storage tank 34. The pump 40 is provided in the pretreatment liquid path 45.

[0044] The pump 41 (corresponding to the second liquid feeding part) pumps the waste liquid of the pretreatment liquid from the pretreatment liquid storage tank 34 to the mixed liquid container 38. The pump 41 is provided in the pretreatment liquid path 46.

[0045] The pump 42 pumps the waste liquid of the ink from the waste liquid receiving parts 33B to 31F to the ink storage tank 35. The pump 42 is provided in the ink path 47.

[0046] The pump 43 (corresponding to the third liquid feeding part) pumps the waste liquid of the ink from the ink storage tank 35 to the mixed liquid container 38. The pump 43 is provided in the ink path 48.

[0047] The pump 44 (corresponding to the first liquid feeding part) pumps the waste liquid of the ink from the ink storage tank 35 to the waste liquid bottle 39. The pump 44 is provided in the ink path 49.

[0048] The pretreatment liquid path 45 connects the waste liquid receiving part 33A and the pretreatment liquid storage tank 34, and forms a flow path for the waste liquid of the pretreatment liquid to be pumped from the waste liquid receiving part 33A to the pretreatment liquid storage tank 34.

[0049] The pretreatment liquid path 46 connects the pretreatment liquid storage tank 34 and the mixed liquid container 38, and forms a flow path for the waste liquid of the pretreatment liquid to be pumped from the pretreatment liquid storage tank 34 to the mixed liquid container 38.

[0050] The ink path 47 connects the waste liquid receiving part 33B and the ink storage tank 35. Also, the ink path 47 is connected to the waste liquid receiving parts 33C to 31F (not shown) by four corresponding paths (not shown) on the upstream side of the pump 42. Thereby, the ink path 47 forms a flow path for the waste liquid of the ink to be pumped from the waste liquid receiving parts 33B to 31F to the ink storage tank 35 on the downstream side of the point where the above four paths are connected.

[0051] The ink path 48 connects the ink storage tank 35 and the mixed liquid container 38, and forms a flow path for waste liquid of the ink that is sent from the ink storage tank 35 to the mixed liquid container 38.

[0052] The ink path 49 connects the ink storage tank 35 and the waste liquid bottle 39, and forms a flow path for waste liquid of the ink that is sent from the ink storage tank 35 to the waste liquid bottle 39.

[0053] The stirring unit 50 stirs the mixed liquid of the waste liquid of the ink and the waste liquid of the pretreatment liquid in the mixed liquid container 38. The stirring unit 50 stirs the mixed liquid in the mixed liquid container 38, for example, by shaking the mixed liquid container 38. When the mixed liquid container 38 is a flexible container such as a pouch, the stirring unit 50 may stir the mixed liquid in the mixed liquid container 38 by kneading the mixed liquid container 38.

[0054] The water-absorbing polymer input unit 51 inputs a water-absorbing polymer into the mixed liquid container 38 in which the waste liquid of the ink has aggregated with the waste liquid of the pretreatment liquid to form an aggregate.

[0055] The wiping unit 5 wipes the nozzle surfaces of the head 21A to which the pretreatment liquid discharged by purging adheres and the nozzle surfaces of the heads 21B to 21F to which the ink discharged by purging adheres during the maintenance operation of the heads 21A to 21F. The wiping unit 5 includes six wipers (not shown) that wipe the respective nozzle surfaces of the heads 21A to 21F.

[0056] The control unit 6 controls the operation of the entire printing apparatus 1. The control unit 6 is configured to include a CPU, a RAM, a ROM, a hard disk, and the like.

[0057] During the maintenance operation of the heads 21A to 21F, the control unit 6 discharges the pretreatment liquid from the head 21A and discharges the ink from the heads 21B to 21F by purging. After that, the control unit 6 causes the wiping unit 5 to wipe the nozzle surfaces of the heads 21A to 21F.

[0058] Further, the control unit 6 controls the pump 40 to send the waste liquid of the pretreatment liquid generated by purging from the waste liquid receiving part 33A to the pretreatment liquid storage tank 34. Further, the control unit 6 controls the pump 43 to send the waste liquid of the ink generated by purging from the waste liquid receiving parts 33B to 33F to the ink storage tank 35.

[0059] Further, the control unit 6 controls the pump 41 to send the waste liquid of the pretreatment liquid from the pretreatment liquid storage tank 34 to the mixed liquid container 38, and controls the pump 43 to send the amount of the waste liquid of the ink within the range of being aggregated by the amount of the waste liquid of the pretreatment liquid sent to the mixed liquid container 38 from the ink storage tank 35, and controls the pump 44 to send the waste liquid of the ink other than that sent to the mixed liquid container 38 from the ink storage tank 35 to the waste liquid bottle 39.

[0060] Here, the control unit 6 stores in advance the range of the ratio of the amount of the pretreatment liquid suitable for aggregating the ink to the amount of the ink. The control unit 6 determines the amount of the waste liquid of the ink to be sent from the ink storage tank 35 to the mixed liquid container 38 based on this ratio range and the amount of the pretreatment liquid sent to the mixed liquid container 38. The range of the ratio of the amount of the pretreatment liquid suitable for aggregating the ink to the amount of the ink is, for example, obtained in advance by experiments.

[0061] Next, the above-mentioned pretreatment liquid will be described.

[0062] The pretreatment liquid is a liquid for aggregating the ink. As the pretreatment liquid, a pretreatment liquid containing a flocculant and water can be preferably used.

[0063] As the flocculant, a component having an action of aggregating the coloring material in the ink on the cloth which is the printing medium can be used. By this, when ink is further applied to the cloth to which the pretreatment liquid is applied, the coloring material in the ink aggregates on the cloth, the image density can be increased more, and bleeding of the image can be prevented. As specific examples of the flocculant, metal salts, cationic polymers, organic acids, etc., or combinations thereof can be used.

[0064] The total amount of the flocculant is preferably 1 to 30% by mass, more preferably 3 to 30% by mass, and still more preferably 5 to 15% by mass, based on the total amount of the pretreatment liquid, in terms of the active ingredient amount.

[0065] As the metal salt, a polyvalent metal salt can be preferably used.

[0066] The polyvalent metal salt is composed of a polyvalent metal ion of 2 or more valences and an anion. Examples of the polyvalent metal ion of 2 or more valences include Ca 2+ , Mg 2+ , Cu 2+ , Ni 2+ , Zn 2+ , Ba 2+ , etc. Examples of the anion include Cl - , NO 3- , CH3COO - , I - , Br - , ClO3 - , etc. Specific examples of the polyvalent metal salt include calcium chloride, calcium nitrate, magnesium nitrate, copper nitrate, calcium acetate, magnesium acetate, etc.

[0067] As the cationic polymer, a cationic water-soluble resin can be preferably used. Examples of the cationic water-soluble resin include polyethyleneimine (PEI), polyvinylamine, polyallylamine and its salts, polyvinylpyridine, copolymers of cationic acrylamide, etc. More specifically, for example, polydiallyldimethylammonium chloride, etc. can be used.

[0068] Examples of the organic acid include formic acid, acetic acid, oxalic acid, malic acid, citric acid, ascorbic acid, and the like.

[0069] The pretreatment liquid preferably contains water. The pretreatment liquid may contain a water-soluble organic solvent in addition to or in place of water.

[0070] The water is not particularly limited, and examples thereof include ion-exchanged water, distilled water, ultrapure water, and the like.

[0071] The water preferably accounts for 30 to 90% by mass, more preferably 40 to 85% by mass, and even more preferably 50 to 80% by mass based on the total amount of the pretreatment liquid.

[0072] As the water-soluble organic solvent, an organic compound that is liquid at room temperature (25°C) and soluble in water can be used, and a water-soluble organic solvent that is uniformly mixed with the same volume of water at 1 atm and 20°C is preferably used. For example, lower alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, 1,3-propanediol, 1,3-butanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 2-methyl-2-propanol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol; glycerins such as glycerin, diglycerin, triglycerin, polyglycerin; acetins such as monoacetin, diacetin; Glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether; β-thiodiglycol, sulfolane, etc. can be used. The boiling point of the water-soluble organic solvent is preferably 100 °C or higher, more preferably 150 °C or higher.

[0073] These water-soluble organic solvents may be used alone or in combination of two or more as long as they form a single phase with water. When two or more water-soluble organic solvents are contained, the total content is preferably 10 to 50% by mass, more preferably 15 to 40% by mass, and even more preferably 15 to 30% by mass based on the total amount of the pretreatment liquid.

[0074] The pretreatment liquid may further contain a surfactant. As the surfactant, any of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant may be used, but a nonionic surfactant is more preferable. Also, either a low-molecular surfactant or a high-molecular surfactant may be used.

[0075] The HLB value of the surfactant is preferably 5 to 20, more preferably 10 to 18.

[0076] Examples of nonionic surfactants include ester surfactants such as glycerin fatty acid esters and sorbitan fatty acid esters; ether surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, and polyoxypropylene alkyl ethers; ether ester surfactants such as polyoxyethylene sorbitan fatty acid esters; acetylene surfactants; silicone surfactants; and fluorine surfactants. Among them, acetylene surfactants such as acetylene glycol surfactants can be preferably used.

[0077] Examples of acetylene surfactants include acetylene glycol surfactants, acetylene alcohol surfactants, and surfactants having an acetylene group.

[0078] Acetylene glycol surfactants are glycols having an acetylene group, preferably glycols having a symmetrical structure with the acetylene group located in the center, and may have a structure in which ethylene oxide is added to acetylene glycol.

[0079] Examples of commercially available acetylene surfactants include Surfynol series "Surfynol 104E", "Surfynol 104H", "Surfynol 420", "Surfynol 440", "Surfynol 465", "Surfynol 485", etc. manufactured by Evonik Industries, and Orfin series "Orfin E1004", "Orfin E1010", "Orfin E1020", etc. manufactured by Nissin Chemical Industry Co., Ltd. (all are trade names).

[0080] Examples of silicone surfactants include polyether-modified silicone surfactants, alkyl·aralkyl co-modified silicone surfactants, acrylic silicone surfactants, and the like.

[0081] Examples of commercially available silicone-based surfactants include, for example, "Silface SAG002", "Silface 503A", etc. manufactured by Nissin Chemical Industry Co., Ltd. (all are trade names).

[0082] In addition, as other nonionic surfactants, for example, polyoxyethylene alkyl ether-based surfactants such as the Emulgen series "Emulgen 102KG", "Emulgen 103", "Emulgen 104P", "Emulgen 105", "Emulgen 106", "Emulgen 108", "Emulgen 120", "Emulgen 147", "Emulgen 150", "Emulgen 220", "Emulgen 350", "Emulgen 404", "Emulgen 420", "Emulgen 705", "Emulgen 707", "Emulgen 709", "Emulgen 1108", "Emulgen 4085", "Emulgen 2025G", etc. manufactured by Kao Corporation can be mentioned (all are trade names).

[0083] Examples of anionic surfactants include, for example, the Emal series "Emal 0", "Emal 10", "Emal 2F", "Emal 40", "Emal 20C", etc., the Neoperex series "Neoperex GS", "Neoperex G-15", "Neoperex G-25", "Neoperex G-65", etc., the Perex series "Perex OT-P", "Perex TR", "Perex CS", "Perex TA", "Perex SS-L", "Perex SS-H", etc., and the Demol series "Demol N, Demol NL", "Demol RN", "Demol MS", etc. manufactured by Kao Corporation (all are trade names).

[0084] Examples of cationic surfactants include, for example, the Acetamin series "Acetamin 24", "Acetamin 86", etc., the Cothamin series "Cothamin 24P", "Cothamin 86P", "Cothamin 60W", "Cothamin 86W", etc., and the Sanizol series "Sanizol C", "Sanizol B-50", etc. manufactured by Kao Corporation (all are trade names).

[0085] Examples of amphoteric surfactants include, for example, the Anitol series products of Kao Corporation, such as "Anitol 20BS", "Anitol 24B", "Anitol 86B", "Anitol 20YB", "Anitol 20N", etc. (all are trade names).

[0086] The surfactant may be used alone or in combination of two or more.

[0087] The surfactant is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, based on the total amount of the pretreatment liquid in terms of the active ingredient amount. When two or more surfactants are used, the content of the above-mentioned surfactant is the total content thereof.

[0088] The pretreatment liquid may further contain other components. Examples of other components include pH adjusters, preservatives, rust preventives, antifoaming agents, etc.

[0089] The method for producing the pretreatment liquid is not particularly limited and can be appropriately produced by known methods. For example, all components can be charged and dispersed into a stirrer such as a three-one motor all at once or in portions, and if desired, it can be obtained by passing through a filter such as a membrane filter.

[0090] Next, the above-mentioned white ink will be described.

[0091] The white ink is discharged onto the cloth in order to conceal the color of the cloth and make the printed image easier to view even when the cloth, which is the printing medium, is a dark color such as black.

[0092] The white ink can contain a white pigment as a coloring material. By containing a white pigment, the white ink can be used to form an image presenting white. The white pigment can be either an inorganic pigment or an organic pigment, or a combination of these can be used.

[0093] Examples of the white pigment include white inorganic pigments such as titanium oxide, zinc white, zinc sulfide, antimony oxide, and zirconium oxide. Furthermore, white organic pigments such as hollow resin fine particles and solid resin fine particles can also be used. Among them, from the viewpoint of hiding power, it is preferable to use a titanium oxide pigment. The average particle diameter of the white pigment is preferably 50 nm or more, 100 nm or more, or 200 nm or more from the viewpoint of hiding power, and preferably 500 nm or less, 400 nm or less, or 300 nm or less from the viewpoint of ejection stability. The average particle diameter of the titanium oxide pigment is more preferably 200 to 300 nm from the viewpoints of hiding power and ejection stability. When using a titanium oxide pigment, in order to suppress the photocatalytic action, it is preferable to use one surface-treated with alumina, silica, etc. The surface treatment amount is preferably 5 to 20% by mass in the pigment.

[0094] Self-dispersible pigments may be used as the white pigment. A self-dispersible pigment is a pigment in which a hydrophilic functional group is introduced onto the surface of the pigment by chemical treatment or physical treatment. As the hydrophilic functional group to be introduced into the self-dispersible pigment, those having ionic properties are preferable, and by charging the pigment surface anionic or cationic, the pigment particles can be stably dispersed in water by electrostatic repulsion force. As the anionic functional group, a carboxy group, a sulfo group, a phosphoric acid group, etc. are preferable. As the cationic functional group, a quaternary ammonium group, a quaternary phosphonium group, etc. are preferable.

[0095] These hydrophilic functional groups may be directly bonded to the pigment surface or may be bonded via other atomic groups. Examples of the other atomic groups include, but are not limited to, an alkylene group, a phenylene group, and a naphthylene group. Examples of the treatment method for the pigment surface include diazotization treatment, sulfonation treatment, hypochlorous acid treatment, humic acid treatment, and vacuum plasma treatment.

[0096] Moreover, as the white pigment, a pigment dispersion in which the pigment is previously dispersed with a pigment dispersant may be used. Also, as the white pigment, a microencapsulated pigment in which the pigment is coated with a resin may be used.

[0097] The white pigment may be used alone or in combination of two or more.

[0098] From the viewpoint of hiding power and the like, the white pigment is preferably 5 to 30% by mass, more preferably 8 to 20% by mass, and even more preferably 10 to 12% by mass based on the total amount of the white ink.

[0099] In order to stably disperse the white pigment in the white ink, a pigment dispersant typified by a polymer dispersant, a surfactant type dispersant, etc. can be used.

[0100] Examples of the polymer dispersant include, as commercially available products, TEGO Disperse series such as "TEGO Disperse 740W", "TEGO Disperse 750W", "TEGO Disperse 755W", "TEGO Disperse 757W", "TEGO Disperse 760W" manufactured by EVONIK; Solsperse series such as "Solsperse 20000", "Solsperse 27000", "Solsperse 41000", "Solsperse 41090", "Solsperse 43000", "Solsperse 44000", "Solsperse 46000" manufactured by Lubrizol Japan Co., Ltd.; Joncryl series such as "Joncryl 57", "Joncryl 60", "Joncryl 62", "Joncryl 63", "Joncryl 71", "Joncryl 501" manufactured by BASF Japan Ltd.; "DISPERBYK-102", "DISPERBYK-185", "DISPERBYK-190", "DISPERBYK-193", "DISPERBYK-199" manufactured by BYK Japan Co., Ltd.; "Polyvinylpyrrolidone K-30", "Polyvinylpyrrolidone K-90" manufactured by Daiichi Kogyo Seiyaku Co., Ltd. (all are trade names).

[0101] Examples of surfactant-based dispersants include anionic surfactants such as the Demol series "Demol P", "Demol EP", "Demol N", "Demol RN", "Demol NL", "Demol RNL", "Demol T-45", etc. manufactured by Kao Corporation, and nonionic surfactants such as the Emulgen series "Emulgen A-60", "Emulgen A-90", "Emulgen A-500", "Emulgen B-40", "Emulgen L-40", "Emulgen 420", etc. manufactured by Kao Corporation (all are trade names).

[0102] The pigment dispersant may be used alone or in combination of two or more.

[0103] When using a pigment dispersant, its content in the ink varies depending on the type and is not particularly limited. Generally, a mass ratio of the active ingredient of 0.005 to 0.5 with respect to 1 of the white pigment is preferred.

[0104] The white ink preferably contains water and the main solvent may be water. The water is not particularly limited, but those containing as little ionic components as possible are preferred. In particular, from the viewpoint of the storage stability of the white ink, it is preferable that the content of polyvalent metal ions such as calcium is small. As the water, for example, ion-exchanged water, distilled water, ultrapure water, etc. may be used.

[0105] From the viewpoint of adjusting the ink viscosity, water is preferably contained in an amount of 30 to 90% by mass, more preferably 40 to 85% by mass, and even more preferably 50 to 80% by mass based on the total amount of the white ink.

[0106] The white ink can contain a water-soluble organic solvent.

[0107] As the water-soluble organic solvent, for example, those described in the above pretreatment liquid can be selected and used.

[0108] Among them, from the viewpoints of adjusting the ink viscosity and moisture retention, glycols, glycerols, or a combination thereof are preferable. As the glycols, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol are preferable. As the glycerols, glycerol is preferable.

[0109] The above water-soluble organic solvents may be used alone, or two or more thereof may be used in combination as long as they form a single phase with water. When two or more water-soluble organic solvents are included, the content thereof is preferably 10 to 50% by mass, more preferably 15 to 40% by mass, and even more preferably 15 to 30% by mass, based on the total amount of the white ink.

[0110] The white ink may further contain a surfactant. As the surfactant, for example, it can be selected from those described in the above pretreatment liquid and used. As the surfactant, any of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant may be used, but a nonionic surfactant is more preferable. Also, either a low-molecular surfactant or a high-molecular surfactant may be used.

[0111] The content of the surfactant is preferably 0.1 to 5% by mass, more preferably 0.2 to 2% by mass, based on the total amount of the white ink.

[0112] The white ink may further contain a water-dispersible resin, a water-soluble resin, or a combination thereof. From the viewpoint of sufficiently fixing the pigment on the cloth and thereby obtaining high colorability with a small amount of pigment, the white ink preferably contains at least one of a water-dispersible resin and a water-soluble resin.

[0113] Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, neutralized polyacrylic acid, acrylic acid / maleic acid copolymer, acrylic acid / sulfonic acid copolymer, styrene / maleic acid copolymer, etc. These may be used alone or in combination of two or more.

[0114] The water-dispersible resin is preferably resin particles dispersible in an aqueous solvent. The water-dispersible resin can be blended into the ink as, for example, an oil-in-water type resin emulsion.

[0115] The water-dispersible resin may be a self-emulsifying type into which a hydrophilic component is introduced in order to be stably dispersed in water, or may be one that becomes water-dispersible by using an external emulsifier.

[0116] From the viewpoint of inkjet ejection property, the average particle diameter of the water-dispersible resin is preferably 300 nm or less, more preferably 200 nm or less, and still more preferably 150 nm or less. For example, the average particle diameter of the water-dispersible resin may be in the range of 10 nm to 300 nm.

[0117] Here, the average particle diameter of the resin is the average particle diameter based on volume and is a numerical value measured by the light scattering method.

[0118] The water-dispersible resin may be any of anionic, cationic, nonionic, and amphoteric. From the viewpoint of more stably dispersing the water-dispersible resin in the aqueous ink, the water-dispersible resin is preferably anionic or nonionic.

[0119] As the water-dispersible resin, an anionic water-dispersible resin having anionic functional groups such as carboxy group, sulfo group, and hydroxy group is preferable.

[0120] As the type of the water-dispersible resin, a resin that forms a transparent coating film is preferably used. Further, the water-dispersible resin can be blended as a resin emulsion in the production of the ink.

[0121] Typical examples include urethane resins, (meth)acrylic resins, styrene / (meth)acrylic resins, polyester resins, olefin resins, vinyl chloride resins, vinyl acetate resins, melamine resins, amide resins, ethylene-vinyl chloride copolymer resins, styrene-(meth)acrylic resins, styrene-maleic anhydride copolymer resins, vinyl acetate-(meth)acrylic copolymer resins, vinyl acetate-ethylene copolymer resins, silicone resins, and the like, as well as composite resins thereof.

[0122] As the water-dispersible resin, a water-dispersible urethane resin, a water-dispersible polyester resin, or a combination thereof is preferred.

[0123] Examples of commercially available water-dispersible resins include "Superflex 470" (water-dispersible urethane resin) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., "Eter KT9204" (water-dispersible polyester resin) manufactured by Unitika Ltd., etc. (all are trade names).

[0124] The above-mentioned water-dispersible resin may be used alone or in combination of two or more.

[0125] The water-dispersible resin preferably has a non-volatile content of 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total amount of the white ink. The water-dispersible resin preferably has a non-volatile content of 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the total amount of the white ink. For example, the water-dispersible resin preferably has a non-volatile content of 1 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 20% by mass, based on the total amount of the white ink.

[0126] The water-dispersible resin preferably has a mass ratio of non-volatile content of 0.1 to 10, more preferably 1 to 3, relative to Pigment 1.

[0127] The total amount of the water-dispersible resin and the water-soluble resin is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more in terms of the non-volatile content with respect to the total amount of the white ink. The total amount of the water-dispersible resin and the water-soluble resin is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less in terms of the non-volatile content with respect to the total amount of the white ink. For example, the total amount of the water-dispersible resin and the water-soluble resin is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 20% by mass in terms of the non-volatile content with respect to the total amount of the white ink.

[0128] The total amount of the water-dispersible resin and the water-soluble resin is preferably 0.1 to 10, more preferably 1 to 3 in terms of the mass ratio of the non-volatile content to Pigment 1.

[0129] The white ink may further contain other components. Examples of the other components include pH adjusters, preservatives, rust preventives, defoamers, amine compounds, and the like.

[0130] The method for producing the white ink is not particularly limited and can be appropriately produced by a known method. For example, all components can be charged into a stirrer such as a three-one motor all at once or dividedly and dispersed, and if desired, the ink can be obtained by passing it through a filter such as a membrane filter.

[0131] From the viewpoint of the storage stability of the ink, the pH of the white ink is preferably 7.0 to 10.0, more preferably 7.5 to 9.0.

[0132] The viscosity of the white ink can be adjusted as appropriate. For example, from the viewpoint of ejection performance, the viscosity at 23°C is preferably 1 to 30 mPa·s.

[0133] Next, the aforementioned color ink will be described.

[0134] In this embodiment, as the color ink, black ink, cyan ink, magenta ink, and yellow ink are used.

[0135] The color ink can contain, as colorants, pigments, dyes, or combinations thereof, and preferably can contain pigments.

[0136] As the pigment, it is preferable to contain non-white pigments.

[0137] As the non-white pigments, organic pigments such as azo pigments, phthalocyanine pigments, polycyclic pigments, and lake pigments, and inorganic pigments such as carbon black and metal oxides can be used. Examples of azo pigments include soluble azo lake pigments, insoluble azo pigments, and condensed azo pigments. Examples of phthalocyanine pigments include metal phthalocyanine pigments and metal-free phthalocyanine pigments. Examples of polycyclic pigments include quinacridone-based pigments, perylene-based pigments, perinone-based pigments, isoindoline-based pigments, isoindolinone-based pigments, dioxazine-based pigments, thioindigo-based pigments, anthraquinone-based pigments, quinophthalone-based pigments, metal complex pigments, and diketopyrrolopyrrole (DPP). Examples of carbon black include furnace carbon black, lamp black, acetylene black, and channel black. These pigments may be used alone or in combination of two or more.

[0138] From the viewpoints of ejection stability and storage stability, the average particle diameter of the pigment particles in the ink is preferably 300 nm or less, more preferably 150 nm or less, and even more preferably 100 nm or less, as the volume-based average value in the particle size distribution measured by the dynamic light scattering method.

[0139] Self-dispersible pigments may be used as the non-white pigments. The details of the self-dispersible pigments are as described for the white pigments.

[0140] As the self-dispersing pigment, for example, CAB-O-JET series products such as "CAB-O-JET200", "CAB-O-JET300", "CAB-O-JET250C", "CAB-O-JET260M", "CAB-O-JET270", "CAB-O-JET450C" manufactured by Cabot Corporation, and "BONJET BLACK CW-1", "BONJET BLACK CW-2", "BONJET BLACK CW-3", "BONJET BLACK CW-4" manufactured by Orient Chemical Industries Co., Ltd. etc. can be preferably used (all are trade names).

[0141] As the pigment, microencapsulated pigments in which the pigment is coated with a resin may be used.

[0142] A pigment dispersion in which the pigment is pre-dispersed with a pigment dispersant may be used. Examples of commercially available products of pigment dispersions dispersed with a pigment dispersant include the HOSTAJET series manufactured by Clariant and the FUJI SP series manufactured by Fuji Pigment Co., Ltd. etc.

[0143] As the dye, water-soluble dyes among basic dyes, acidic dyes, direct dyes, soluble vat dyes, acid mordant dyes, mordant dyes, reactive dyes, vat dyes, sulfur dyes etc. and water-soluble dyes made water-soluble by reduction etc. can be preferably used. Also, disperse dyes such as azo-based, anthraquinone-based, azomethine-based, nitro-based etc. can be preferably used. These may be used alone or in combination of multiple types.

[0144] The colorant may be used alone or in combination of two or more types.

[0145] From the viewpoints of printing density and ink viscosity, the content of the colorant is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass, and even more preferably 2 to 7% by mass based on the total amount of the color ink.

[0146] When using a pigment as a coloring material in a color ink, in order to stably disperse the pigment in the color ink, a pigment dispersant typified by a polymer dispersant, a surfactant type dispersant, etc. can be used. As the pigment dispersant, for example, it can be selected and used from those described for the above-mentioned white ink.

[0147] When using a pigment dispersant, the content in the color ink varies depending on its type and is not particularly limited. Generally, in terms of the mass ratio of the active ingredient, 0.005 to 0.5 is preferable with respect to pigment 1.

[0148] The color ink preferably contains water. The color ink may contain, in addition to water, or instead of water, a water-soluble organic solvent. Details of water and the water-soluble organic solvent are as described for the above-mentioned white ink. As the water-soluble organic solvent, for example, it can be selected and used from those described for the above-mentioned white ink.

[0149] From the viewpoint of adjusting the ink viscosity, water is preferably contained in an amount of 20% to 80% by mass, more preferably 30% to 70% by mass, based on the total amount of the color ink.

[0150] The water-soluble organic solvent is preferably 5 to 50% by mass, more preferably 10 to 30% by mass, based on the total amount of the color ink.

[0151] The color ink may further contain a surfactant. As the surfactant, for example, it can be selected and used from those described for the above-mentioned white ink. Among them, a nonionic surfactant is preferable, and an acetylene-based surfactant such as an acetylene glycol-based surfactant is more preferable.

[0152] The surfactant is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, based on the total amount of the color ink in terms of the amount of the active ingredient.

[0153] The color ink may further contain resins such as a water-dispersible resin and a water-soluble resin. For example, by including a fixing resin, the color ink can enhance the fixability of the printed image to the fabric and the coating film strength of the image. From the viewpoint of obtaining ejection properties and storage stability suitable for inkjet ink, it is preferable for the color ink to contain a water-dispersible resin. The water-dispersible resin is preferably one that is blended in the form of a water-in-oil emulsion in the color ink and can be dispersed in the form of resin particles in the color ink. As the water-dispersible resin, for example, those described for the white ink above can be selected and used, and it may be a water-dispersible urethane resin, other water-dispersible resins, or a combination thereof.

[0154] The water-dispersible resin is preferably 1 to 30% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 20% by mass based on the total amount of the color ink.

[0155] The color ink may further contain a crosslinking agent. By including a crosslinking agent in the color ink, the coating film strength of the image can be further enhanced. By increasing the coating film strength, cracking of the image can be more suppressed even after washing the printed matter. Examples of the crosslinking agent include carbodiimide-based compounds, isocyanate-based compounds, oxazoline-based compounds, and the like.

[0156] The crosslinking agent is preferably 0.1 to 5% by mass, more preferably 0.2 to 2% by mass based on the total amount of the color ink.

[0157] The color ink may further contain other components. Examples of the other components include pH adjusters, preservatives, rust preventives, defoamers, and the like.

[0158] The method for producing the color ink is not particularly limited, and it can be appropriately produced by a known method. For example, all components can be charged and dispersed into a stirrer such as a three-one motor all at once or in portions, and if desired, the ink can be obtained by passing it through a filter such as a membrane filter.

[0159] From the perspective of the storage stability of the ink, the pH of the color ink is preferably from 7.0 to 10.0, more preferably from 7.5 to 9.0.

[0160] The viscosity of the color ink can be adjusted as appropriate. For example, from the perspective of ejection performance, the viscosity at 23°C is preferably 1 to 30 mPa·s.

[0161] Next, the maintenance operation of the head 21 in the printing apparatus 1 will be described.

[0162] First, the control unit 6 discharges the pretreatment liquid from the head 21A and discharges the ink from the heads 21B to 21F by purging. Specifically, with the head unit 11 arranged above the capping unit 4, the control unit 6 applies a predetermined pressure to the heads 21A to 21F by a pressure generating unit (not shown). Thereby, the pretreatment liquid is discharged from the head 21A, and the ink is discharged from the heads 21B to 21F.

[0163] During this purging, the nozzle surface of each head 21 may be sealed by each cap portion 31 or may be open. However, it is preferable to seal the nozzle surface of each head 21 by each cap portion 31. Thereby, it is possible to prevent the entry of dust and other dirt into each cap portion 31 and the contamination of the periphery of each cap portion 31 with ink.

[0164] A part of the pretreatment liquid discharged from the head 21A by purging adheres to the nozzle surface of the head 21A, and the remaining pretreatment liquid falls from the nozzle surface and is received as waste liquid by the cap portion 31A. The waste liquid of the pretreatment liquid received by the cap portion 31A is discharged from the discharge hole 31e to the waste liquid receiving portion 33A.

[0165] Also, in each of the heads 21B to 21F, a part of the ink discharged by purging adheres to the respective nozzle surfaces, and the remaining ink drops from the nozzle surfaces and is received by the corresponding cap portions 31B to 31F as waste liquid. The waste liquid of the ink received in each of the cap portions 31B to 31F is discharged from the discharge holes 31e to the corresponding waste liquid receiving portions 33B to 33F.

[0166] After the purging is completed, the control unit 6 moves the head unit 11 to the position of the wiping unit 5 by the rail unit 12. After that, the control unit 6 controls the wiping unit 5 to wipe the nozzle surfaces of the heads 21A to 21F with the corresponding wipers.

[0167] Also, after the purging is completed, the control unit 6 drives the pump 40 to send the waste liquid of the pretreatment liquid from the waste liquid receiving portion 33A to the pretreatment liquid storage tank 34. Also, the control unit 6 drives the pump 42 to send the waste liquid of the ink from the waste liquid receiving portions 33B to 33F to the ink storage tank 35.

[0168] Next, the control unit 6 drives the pump 41 to send the waste liquid of the pretreatment liquid from the pretreatment liquid storage tank 34 to the mixed liquid container 38.

[0169] Also, the control unit 6 drives the pump 43 to send the amount of the waste liquid of the ink in the range aggregated by the amount of the waste liquid of the pretreatment liquid sent to the mixed liquid container 38 from the ink storage tank 35 to the mixed liquid container 38. Also, the control unit 6 drives the pump 44 to send the waste liquid of the ink in the ink storage tank 35 other than the waste liquid of the ink sent to the mixed liquid container 38 to the waste liquid bottle 39.

[0170] Here, the control unit 6 can determine the amount of the waste liquid of the pretreatment liquid sent from the pretreatment liquid storage tank 34 to the mixed liquid container 38 based on the change in the liquid amount detected by the liquid amount detection unit 36. Also, the control unit 6 can determine the amount of the waste liquid of the ink sent from the ink storage tank 35 to the mixed liquid container 38 based on the change in the liquid amount detected by the liquid amount detection unit 37.

[0171] Also, as described above, the control unit 6 stores in advance the range of the ratio of the amount of the pretreatment liquid suitable for aggregating the ink to the amount of the ink, and based on this range of the ratio, determines the amount of the waste liquid of the ink to be fed from the ink storage tank 35 to the mixing liquid container 38.

[0172] Next, the preparation operation when the user discards the aggregates in the mixing liquid container 38 in the printing apparatus 1 will be described.

[0173] This preparation operation is carried out when the mixing liquid container 38 is full. When the weight of the mixing liquid container 38 including the mixed liquid (aggregate) of the waste liquid of the ink and the waste liquid of the pretreatment liquid in the mixing liquid container 38 detected by the weight detection unit (not shown) reaches the weight indicating that the mixing liquid container 38 is full, the control unit 6 determines that the mixing liquid container 38 is full.

[0174] When the mixing liquid container 38 is full, the control unit 6 controls the stirring unit 50 to stir the mixed liquid in the mixing liquid container 38 for a preset predetermined time. Thereby, the waste liquid of the ink in the mixing liquid container 38 uniformly aggregates to form a gel-like solid aggregate.

[0175] Here, even before the stirring, aggregation occurs in the mixing liquid container 38 due to the reaction between the waste liquid of the ink and the waste liquid of the pretreatment liquid, but by stirring, the overall aggregation proceeds and aggregates are formed.

[0176] After the stirring is completed, the control unit 6 controls the water-absorbing polymer input unit 51 to input a water-absorbing polymer into the mixing liquid container 38 in which the aggregates are formed.

[0177] Here, as described above, after feeding the waste liquid of the ink in an amount within the range that aggregates due to the waste liquid of the pretreatment liquid fed to the mixing liquid container 38 and stirring the mixed liquid, there may be a small amount of liquid in the mixing liquid container 38. In contrast, by inputting a water-absorbing polymer into the mixing liquid container 38, even if there is liquid in the mixing liquid container 38, the water-absorbing polymer can absorb the liquid to remove the liquid.

[0178] This can prevent the liquid from spilling when the user performs the operation of discarding the aggregates in the mixed liquid container 38. Further, when the mixed liquid container 38 is a container such as a pouch that can be discarded as a whole, it is possible to prevent the container from being torn and the liquid from leaking.

[0179] The amount of the water-absorbing polymer to be put into the mixed liquid container 38 varies depending on its water absorption capacity and is not particularly limited. For example, it is 1 to 2% of the weight of the aggregates (mixed liquid) in the mixed liquid container 38.

[0180] When the water-absorbing polymer is added, the preparation operation is completed. When the preparation operation is completed, the control unit 6 causes a message instructing the user to discard the aggregates in the mixed liquid container 38 to be displayed on the display unit (not shown) of the operation panel.

[0181] The user who has confirmed the above message discards the aggregates in the mixed liquid container 38. When the mixed liquid container 38 is a container such as a pouch that can be discarded as a whole, the user discards the mixed liquid container 38 containing the aggregates and installs a new mixed liquid container 38.

[0182] In addition, when the waste liquid bottle 39 is full, the control unit 6 causes a message instructing the user to discard the ink in the waste liquid bottle 39 to be displayed on the display unit (not shown) of the operation panel. Here, the control unit 6 determines that the waste liquid bottle 39 is full when the weight of the waste liquid bottle 39 including the waste of the ink in the waste liquid bottle 39 detected by the weight detection unit (not shown) reaches the weight indicating that the waste liquid bottle 39 is full. The user who has confirmed the above message discards the ink in the waste liquid bottle 39.

[0183] Next, experimental examples performed to obtain the range of the ratio of the amounts of the pretreatment liquid suitable for aggregating the ink and the ink will be described.

[0184] In this experiment, 400 g of titanium oxide "R-21N" (manufactured by Sakai Chemical Industry Co., Ltd.) as a white pigment and 20 g (5 g of active ingredient) of "Demol EP" (manufactured by Kao Corporation) as a pigment dispersant were mixed with 580 g of ion-exchanged water, and using a bead mill (manufactured by Shinmaru Enterprises Corporation, DYNO-MILL KDL A type), zirconia beads with a diameter of 0.5 mm were dispersed at a filling rate of 80% and a residence time of 5 minutes to obtain a white pigment dispersion (pigment content: 40% by mass).

[0185] The formulations of the white ink, cyan ink, and pretreatment liquid used in this experiment are shown in Table 1. According to the formulations described in Table 1, the raw materials were mixed and stirred with a mix rotor at 100 rpm for 20 minutes to obtain the white ink, cyan ink, and pretreatment liquid.

[0186] Here, since the cohesiveness of each color ink is the same, in this experiment, cyan ink was used as a representative.

[0187]

Table 1

[0188] The pretreatment liquid and cyan ink or white ink were put into a desiccator cup at the ratios shown in Table 2, and the fluidity when stirred with a dropper was confirmed and evaluated according to the following evaluation criteria. ○: Almost no aggregation is observed △: Slightly aggregated and fluidity decreases a little ×: Aggregated and fluidity almost disappears (becomes a gel-like solid)

[0189]

Table 2

[0190] As shown in Table 2, in both the mixture of the pretreatment liquid and cyan ink and the mixture of the pretreatment liquid and white ink, when the ratio of the pretreatment liquid to the ink was 5:95 to 10:90, a result was obtained where the ink aggregated and the fluidity almost disappeared.

[0191] Therefore, when using the pretreatment liquid and ink (white ink and color ink) used in this experiment in the printing apparatus 1, it is preferable that the ratio of the amount of the pretreatment liquid suitable for aggregating the ink to the ink be 5:95 to 10:90.

[0192] As described above, in the printing apparatus 1, the control unit 6 feeds the waste liquid of the pretreatment liquid from the pretreatment liquid storage tank 34 to the mixed liquid container 38 by the pump 41, and the waste liquid of the ink in an amount within the range of aggregation by the waste liquid of the pretreatment liquid fed to the mixed liquid container 38 is fed from the ink storage tank 35 to the mixed liquid container 38 by the pump 43, and controls to feed the waste liquid of the remaining ink from the ink storage tank 35 to the waste liquid bottle 39 by the pump 44.

[0193] Thereby, by aggregating a part of the waste liquid of the ink with the waste liquid of the pretreatment liquid in the mixed liquid container 38, it becomes possible to discard a part of the waste liquid of the ink and the waste liquid of the pretreatment liquid as solids. As a result, since it is not necessary to discard the waste liquid of the pretreatment liquid as a liquid, the labor for disposal can be reduced as compared with the case of discarding the waste liquid of the pretreatment liquid and the waste liquid of the ink as liquids respectively. Further, since the waste liquid of the ink discharged to the waste liquid bottle 39 is reduced, the frequency of discarding the waste liquid of the ink in the waste liquid bottle 39 can be reduced, so that the labor for disposal can be reduced.

[0194] Further, since a part of the waste liquid of the ink is aggregated with the waste liquid of the pretreatment liquid, it is not necessary to use an additional substance other than the pretreatment liquid and the ink used for printing in the printing apparatus 1.

[0195] Therefore, according to the printing apparatus 1, the labor for disposing of the waste liquid of the pretreatment liquid and the waste liquid of the ink can be reduced without using an additional substance.

[0196] Also, in the printing apparatus 1, by stirring the mixed liquid in the mixed liquid container 38 by the stirring unit 50, the waste liquid of the ink can be efficiently and uniformly aggregated.

[0197] In the printing apparatus 1, the control unit 6 controls the water-absorbing polymer input unit 51 to input a water-absorbing polymer into the mixed liquid container 38 in which aggregates are formed. Thereby, even if there is liquid in the mixed liquid container 38, the liquid can be removed by the water-absorbing polymer. As a result, when the user performs the operation of discarding the aggregates in the mixed liquid container 38, it is possible to prevent the liquid from spilling. Further, when the mixed liquid container 38 is a container such as a pouch that can be discarded as a whole, it is possible to prevent the container from being broken and the liquid from leaking.

[0198] [Second Embodiment] Next, a second embodiment in which the capping unit of the first embodiment described above is modified will be described.

[0199] FIG. 5 is a schematic configuration diagram of the capping unit in the second embodiment.

[0200] As shown in FIG. 5, the capping unit 4A in the second embodiment has a configuration in which the water-absorbing polymer input unit 51 is omitted from the capping unit 4 of the first embodiment, and a filter 61, a pump 62, and a liquid feed path 63 are added.

[0201] The filter 61 is for removing liquid from the mixed liquid container 38 in which aggregates are formed. The filter 61 is disposed so as to cover the end (opening) of the liquid feed path 63 connected to the mixed liquid container 38.

[0202] The pump 62 feeds the liquid flowing out from the mixed liquid container 38 through the filter 61 to the waste liquid bottle 39. The pump 62 is provided in the liquid feed path 63.

[0203] The liquid feed path 63 forms a flow path for the liquid that flows out from the mixed liquid container 38 through the filter 61 and is fed to the waste liquid bottle 39.

[0204] In the second embodiment, after the control unit 6 stirs the liquid mixture in the liquid mixture container 38 by the stirring unit 50, the pump 62 is driven. As a result, when there is a liquid component in the liquid mixture container 38 in which aggregates are formed, the liquid component passes through the filter 61 and flows out into the liquid feed path 63 and is fed to the waste liquid bottle 39. Since it is assumed that the amount of the flocculant contained in the liquid component removed by the filter 61 is extremely small, almost no aggregation occurs in the waste liquid bottle 39.

[0205] As a result, even if there is a liquid component in the liquid mixture container 38, the liquid component can be removed by the filter 61. As a result, similar to the first embodiment, when the user performs the operation of discarding the aggregates in the liquid mixture container 38, it is possible to prevent the liquid component from spilling. Further, when the liquid mixture container 38 is a container such as a pouch that can be discarded as a whole container, it is possible to prevent the container from being broken and the liquid component from leaking.

[0206] [Other Embodiments] As described above, the present invention has been described with reference to the first and second embodiments. However, it should not be understood that the discussions and drawings forming a part of this disclosure limit the present invention. Various alternative embodiments, examples, and operation techniques will be apparent to those skilled in the art from this disclosure.

[0207] In the first and second embodiments described above, the capping units 4 and 4A for collecting the waste liquid of the pretreatment liquid and the waste liquid of the ink generated in the printing apparatus 1 have been described. However, the present invention is not limited to this, and the present invention is applicable to an apparatus for collecting the waste liquid of the first liquid and the waste liquid of the second liquid that aggregates the first liquid.

[0208] Further, in the first and second embodiments described above, the configuration in which the capping units 4 and 4A include the stirring unit 50 that stirs the liquid mixture in the liquid mixture container 38 has been described. However, if the combination of the first liquid and the second liquid to be collected as waste liquid aggregates as a whole without stirring the liquid mixture, the stirring unit can be omitted.

[0209] Further, the water-absorbing polymer input section 51 in the above-described first embodiment may be omitted. Also, the filter 61, pump 62, and liquid feed path 63 in the second embodiment may be omitted. Even in these cases, a part of the waste ink can be aggregated by the waste pretreatment liquid in the mixing liquid container 38, and a part of the waste ink and the waste pretreatment liquid can be discarded as solids.

[0210] Also, in the above-described first and second embodiments, the inkjet printing apparatus 1 that performs printing using cloth as a printing medium has been described as an example. However, the printing medium is not limited to cloth and may be paper or other media.

[0211] Thus, the present invention naturally includes various embodiments and the like not described herein. Therefore, the technical scope of the present invention is defined only by the invention-specific matters according to the reasonable claims based on the above description.

[0212] [Supplementary Note] This application discloses the following inventions.

[0213] (Supplementary Note 1) A first container for storing waste liquid of a first liquid; A second container for mixing and storing the waste liquid of the first liquid and the waste liquid of a second liquid that aggregates the first liquid; A first liquid feed section for feeding the waste liquid of the first liquid to the first container; A second liquid feed section for feeding the waste liquid of the second liquid to the second container; A third liquid feed section for feeding the waste liquid of the first liquid to the second container; A control section that controls the second liquid feed section to feed the waste liquid of the second liquid to the second container, controls the third liquid feed section to feed an amount of the waste liquid of the first liquid within a range that aggregates with the amount of the waste liquid of the second liquid fed to the second container to the second container, and controls the first liquid feed section to feed the waste liquid of the first liquid other than that fed to the second container to the first container A liquid recovery apparatus characterized by comprising the above.

[0214] (Supplementary Note 2) The liquid recovery device according to appended claim 1, further comprising a stirring unit for stirring a mixed liquid of the waste liquid of the first liquid and the waste liquid of the second liquid in the second container.

[0215] (Appended claim 3) The liquid recovery device according to appended claim 1 or 2, further comprising a water-absorbing polymer input unit for inputting a water-absorbing polymer into the second container in which the waste liquid of the first liquid is aggregated by the waste liquid of the second liquid to form an aggregate.

[0216] (Appended claim 4) The liquid recovery device according to appended claim 1 or 2, further comprising a filter for removing liquid components from the second container in which the waste liquid of the first liquid is aggregated by the waste liquid of the second liquid to form an aggregate.

[0217] (Appended claim 5) The first liquid is ink, The liquid recovery device according to appended claim 2, wherein the second liquid is a treatment liquid for aggregating the ink.

Explanation of reference signs

[0218] 1 Printing device 2 Printing unit 3 Conveying unit 4, 4A Capping unit 5 Wiping unit 6 Control unit 11 Head unit 12 Rail part 21, 21A~21F Heads 22 Head holder 31, 31A~31F Cap parts 32 Plate material 33, 33A~33F Waste liquid receiving parts 34 Pretreatment liquid storage tank 35 Ink storage tank 36, 37 Liquid volume detection parts 38 Mixed liquid container 39 Waste liquid bottle 40~44, 62 Pumps 45, 46 Pretreatment liquid path 47 - 49 Ink path 50 Stirring section 51 Water-absorbent polymer input section 61 Filter 63 Liquid delivery path

Claims

1. a first container for storing the waste liquid of the first liquid; a second container for mixing and storing the waste liquid of the first liquid and the waste liquid of a second liquid for aggregating the first liquid; a first liquid feeding section for feeding the waste liquid of the first liquid to the first container; a second liquid feeding section for feeding the waste liquid of the second liquid to the second container; a third liquid feeding section for feeding the waste liquid of the first liquid to the second container; a control section for controlling such that the waste liquid of the second liquid is fed to the second container by the second liquid feeding section, an amount of the waste liquid of the first liquid within a range aggregated by the amount of the waste liquid of the second liquid fed to the second container is fed to the second container by the third liquid feeding section, and the waste liquid of the first liquid other than that fed to the second container is fed to the first container by the first liquid feeding section; A liquid recovery device, characterized by comprising the above.

2. The liquid recovery device according to Claim 1, further comprising a stirring section for stirring a mixture of the waste liquid of the first liquid and the waste liquid of the second liquid in the second container.

3. The liquid recovery device according to Claim 1 or 2, further comprising a water-absorbing polymer feeding section for feeding a water-absorbing polymer into the second container in which an aggregate is formed by aggregating the waste liquid of the first liquid with the waste liquid of the second liquid.

4. The liquid recovery device according to Claim 1 or 2, further comprising a filter for removing liquid components from the second container in which an aggregate is formed by aggregating the waste liquid of the first liquid with the waste liquid of the second liquid.

5. The first liquid is ink; The liquid recovery device according to Claim 2, characterized in that the second liquid is a treatment liquid for aggregating the ink.

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