Abstract: An ink set includes an inkjet ink and a recording head filling liquid. The inkjet ink includes a pigment, a pigment coating resin, a first alkali metal ion, and water. The recording head filling liquid includes polyethylene glycol, a second alkali metal ion, a surfactant, and water. The polyethylene glycol has a mass average molecular weight of at least 180 and no greater than 800. A content ratio of the surfactant in the recording head filling liquid is greater than 0.00% by mass and no greater than 0.10% by mass. The first and second alkali metal ions each contain at least one of Li+, Na+, and K+.

Abstract: An inkjet ink contains a pigment, resin particles, dipropylene glycol monomethyl ether, triethylene glycol monobutyl ether, and propylene glycol. The resin particles contain polycarbonate polyurethane resin. The resin particles have a percentage content of at least 2.0% by mass and no greater than 9.0% by mass. The dipropylene glycol monomethyl ether has a percentage content of at least 7.0% by mass and no greater than 27.0% by mass. The triethylene glycol monobutyl ether has a percentage content of at least 4.0% by mass and no greater than 12.0% by mass. The propylene glycol has a percentage content of at least 4.0% by mass and no greater than 18.0% by mass.

Abstract: A cleaning liquid contains water, a surfactant, and glycol ether. The surfactant includes both a silicone surfactant and a betaine surfactant. The glycol ether has a percentage content of at least 5.0% by mass and no greater than 15.0% by mass relative to the mass of the cleaning liquid. The cleaning liquid has a viscosity at 25° C. of 10.0 mPa·s.

Abstract: A recording head recovery system includes a recording head, a cleaning liquid tank for storing cleaning liquid, a cleaning liquid supplying path which connects together the cleaning liquid tank and the recording head, a liquid supply mechanism which is provided in the cleaning liquid supplying path, and a controller. The controller performs recording head recovery operation including cleaning liquid supplying operation for supplying the cleaning liquid from liquid supplying openings of the recording head, wiping operation for wiping an ink ejection face of the recording head while a wiper retains the cleaning liquid, and backflow operation for controlling the liquid supply mechanism to make the cleaning liquid in the cleaning liquid supplying path to flow from the cleaning liquid supplying openings to the cleaning liquid tank.

Abstract: A cleaning liquid includes water, a surfactant, and glycol ether. The surfactant is an acetylene surfactant or a silicone surfactant. A content ratio of the glycol ether is at least 5% by mass and no greater than 15% by mass relative to a mass of the cleaning liquid. Preferably, a contact angle of the cleaning liquid to an austenitic stainless steel plate is no greater than 40 degrees.

Abstract: A wash fluid for use in an inkjet recording apparatus contains water, a coconut oil fatty acid surfactant, an organic deliquescent agent, a polyhydric alcohol, and a basic inorganic compound. The polyhydric alcohol is an alkanediol. The coconut oil fatty acid surfactant is contained in an amount of at least 0.01% by mass and no greater than 3.00% by mass. The organic deliquescent agent is contained in an amount of at least 0.10% by mass and no greater than 30.00% by mass.

Abstract: An ink set includes an inkjet ink and a recording head filling liquid. The inkjet ink contains a pigment, a pigment covering resin, a glycol ether compound, a first polyhydric alcohol compound, and water. The recording head filling liquid contains polyethylene glycol, a second polyhydric alcohol compound, a nonionic surfactant, and water. The polyethylene glycol has a mass average molecular weight of at least 190 and no greater than 420. A percentage content of the polyethylene glycol in the recording head filling liquid is at least 0.7% by mass and no greater than 12.0% by mass. A percentage content of the second polyhydric alcohol compound in the recording head filling liquid is at least 15.0% by mass and no greater than 45.0% by mass.

Abstract: An ink set includes an inkjet ink and a recording head filling liquid. The inkjet ink contains a pigment, a pigment covering resin, and water. The recording head filling liquid contains polyethylene glycol, a nonionic surfactant, and water. The recording head filling liquid has a viscosity of at least 3 mPa·s and no greater than 10 mPa·s. The polyethylene glycol has a mass average molecular weight of at least 170 and no greater than 300. A percentage content of the polyethylene glycol in the recording head filling liquid is at least 7.0% by mass and no greater than 55.0% by mass. The pigment covering resin includes a styrene-acrylic resin.

Abstract: An ink set includes an inkjet ink and a recording head filling liquid. The inkjet ink includes a pigment, a pigment coating resin, a first alkali metal ion, and water. The recording head filling liquid includes polyethylene glycol, a second alkali metal ion, a surfactant, and water. The polyethylene glycol has a mass average molecular weight of at least 180 and no greater than 800. A content ratio of the surfactant in the recording head filling liquid is greater than 0.00% by mass and no greater than 0.10% by mass. The first and second alkali metal ions each contain at least one of Li+, Na+, and K+.

Abstract: A recording head recovery system includes a recording head, a cleaning liquid tank for storing cleaning liquid, a cleaning liquid supplying path which connects together the cleaning liquid tank and the recording head, a liquid supply mechanism which is provided in the cleaning liquid supplying path, and a controller. The controller performs recording head recovery operation including cleaning liquid supplying operation for supplying the cleaning liquid from liquid supplying openings of the recording head, wiping operation for wiping an ink ejection face of the recording head while a wiper retains the cleaning liquid, and backflow operation for controlling the liquid supply mechanism to make the cleaning liquid in the cleaning liquid supplying path to flow from the cleaning liquid supplying openings to the cleaning liquid tank.

Abstract: A method for recovery of a recording head includes cleaning liquid supplying operation, wiping operation, and backflow operation. The recording head is connected to a cleaning liquid tank for storing cleaning liquid via a cleaning liquid supplying path. In the backflow operation, a liquid supply mechanism makes the cleaning liquid in the cleaning liquid supplying path to flow backward in a direction pointing from the cleaning liquid supplying openings to the cleaning liquid tank. The recording head includes an ink ejection region in which ink ejection openings are open, and a cleaning liquid supplying region which is arranged upstream of the ink ejection region in a wiping direction and in which cleaning liquid supplying openings are open. The backflow operation is performed after a wiper passes the cleaning liquid supplying region and before the wiper reaches the ink ejection region.

Abstract: A wash fluid for use in an inkjet recording apparatus contains water, a coconut oil fatty acid surfactant, an organic deliquescent agent, a polyhydric alcohol, and a basic inorganic compound. The polyhydric alcohol is an alkanediol. The coconut oil fatty acid surfactant is contained in an amount of at least 0.01% by mass and no greater than 3.00% by mass. The organic deliquescent agent is contained in an amount of at least 0.10% by mass and no greater than 30.00% by mass.

Abstract: A recording head recovery system includes a recording head, a cleaning liquid tank for storing cleaning liquid, a cleaning liquid supplying path which connects together the cleaning liquid tank and the recording head, a liquid supply mechanism which is provided in the cleaning liquid supplying path, and a controller. The controller performs recording head recovery operation including cleaning liquid supplying operation for supplying the cleaning liquid from liquid supplying openings of the recording head, wiping operation for wiping an ink ejection face of the recording head while a wiper retains the cleaning liquid, and backflow operation for controlling the liquid supply mechanism to make the cleaning liquid in the cleaning liquid supplying path to flow from the cleaning liquid supplying openings to the cleaning liquid tank.

Abstract: A water-based cleaning liquid for inkjet recording apparatus use contains at least 0.10% by mass and no greater than 10.00% by mass of a nonionic surfactant, at least 0.50% by mass and no greater than 30.00% by mass of a deliquescent agent, and a pH adjuster. The nonionic surfactant contains polyoxyalkylene alkylamine. The deliquescent agent includes at least one of sorbitol, trimethylolpropane, and 1,3-bis(2-hydroxyethyl)-5,5-dimethylhydantoin. The pH adjuster includes an alkali metal salt. The water-based cleaning liquid for inkjet recording apparatus use has a pH of at least 7.5 and no greater than 8.5.

Abstract: An ink set includes a water-based ink and a water-based cleaning liquid. The water-based ink and the water-based cleaning liquid each contain at least 1.0% by mass and no greater than 4.0% by mass of a deliquescent agent. The water-based cleaning liquid further contains a nonionic surfactant and a diol. The deliquescent agent that the water-based ink contains and the deliquescent agent that the water-based cleaning liquid contains each include at least one of sorbitol, trimethylolpropane, and 1,3-bis(2-hydroxyethyl)-5,5-dimethylhydantoin. The nonionic surfactant has an HLB value determined by Griffin method of at least 14 and no greater than 16. The diol includes at least one of triethylene glycol and 1,3-propanediol.

Abstract: An ink set includes a water-based ink and a water-based cleaning liquid. The water-based ink and the water-based cleaning liquid each contain at least 1.0% by mass and no greater than 4.0% by mass of a deliquescent agent. The water-based cleaning liquid further contains a nonionic surfactant and a diol. The deliquescent agent that the water-based ink contains and the deliquescent agent that the water-based cleaning liquid contains each include at least one of sorbitol, trimethylolpropane, and 1,3-bis(2-hydroxyethyl)-5,5-dimethylhydantoin. The nonionic surfactant has an HLB value determined by Griffin method of at least 14 and no greater than 16. The diol includes at least one of triethylene glycol and 1,3-propanediol.

Abstract: A water-based cleaning liquid for inkjet recording apparatus use contains at least 0.10% by mass and no greater than 10.00% by mass of a nonionic surfactant, at least 0.50% by mass and no greater than 30.00% by mass of a deliquescent agent, and a pH adjuster. The nonionic surfactant contains polyoxyalkylene alkylamine. The deliquescent agent includes at least one of sorbitol, trimethylolpropane, and 1,3-bis(2-hydroxyethyl)-5,5-dimethylhydantoin. The pH adjuster includes an alkali metal salt. The water-based cleaning liquid for inkjet recording apparatus use has a pH of at least 7.5 and no greater than 8.5.

Abstract: An ink for ink-jet recording apparatuses includes water, a pigment dispersion, an organic solvent, and a humectant. The pigment dispersion includes a pigment and a resin having a weight average molecular weight of from 35,000 to 140,000. An adsorbed resin proportion determined from the mass of a total amount of resin in the ink and the amount of resin separated from pigment among the resin is at least 0.97. And, the ink contains from 3% to 15% by mass of C1-C4 monoalkyl ether of polyhydric alcohol based on the mass of the ink as the organic solvent.

Abstract: An ink for an ink-jet recording apparatus contains water, a pigment, a resin, 1,3-propanediol, and an organic solvent. The resin has a weight-average molecular weight of 30,000 to 150,000. The content of the resin is 1.5% to 6.0% by mass with respect to the mass of the ink. The total content (P+Q) of the content of the glycerol (P) and the content of the 1,3-propanediol (Q) in the ink is 15% to 40% by mass with respect to the mass of the ink. The mass ratio (P/Q) is 0.25 to 1.00.

Abstract: An inkjet recording apparatus according to one aspect of the present disclosure includes nozzle, pressuring chambers, piezoelectric element, ambient condition obtaining portion, application portion, and control portion. Control portion causes application portion to output ejection driving-voltage by which piezoelectric element is deformed so as to eject droplets from nozzles in printing period in printing state, and causes application portion to output vibration driving-voltage by which piezoelectric element is vibrated so as to vibrate meniscus in each nozzle in non-printing period between printing periods in printing state.