Liquid discharge system

Abstract

The present invention provides a liquid discharge system capable of inhibiting deterioration of landing position accuracy caused by electrification of liquid. This liquid discharge system includes a liquid discharge head (30) provided with a fluid pump chamber (314), a pump chamber communication fluid path (312), and a nozzle, the liquid discharge head having formed, at an end thereof, a nozzle opening (310) for discharging a liquid. The liquid discharge system includes a liquid supply device (100) for supplying the liquid to the liquid discharge head. The liquid supply device is provided with a first tank (114) for storing the liquid, and a first flow path member (116) linked to the first tank and to the liquid discharge head and using non-fluororesin as a material of a portion to be in contact with the liquid.

Description

Liquid dispensing system

[0001] This invention relates to a liquid dispensing system.

[0002] The material used for the flow path supplied to the liquid dispensing head may be a fluororesin that has high resistance to the liquid being used. Examples of fluororesins include polytetrafluoroethylene. The liquid used in the liquid dispensing head may be referred to as ink.

[0003] Patent Document 1 describes a circulation channel for circulating liquid to a head, which consists of a route that returns to the main tank via a liquid path, supply tank, liquid path, head, liquid path, recovery tank, and liquid path. The document also describes the use of a flexible tube for the liquid path.

[0004] Patent Document 2 describes the use of ink-resistant tubing for the main supply path, main return path, ink supply path, ink circulation path, ink return path, and circulation path, and provides polyethylene tubing as an example of the tubing.

[0005] Patent document 3 describes an ink tube having a multilayer structure. The document exemplified polyethylene resin, polypropylene resin, and polyvinyl chloride resin as materials for the innermost layer of the ink tube.

[0006] Japanese Patent Publication No. 2020-196164, Japanese Patent Publication No. 2005-022124, Japanese Patent Publication No. 2000-168099

[0007] Fluororesins have a tendency to become negatively charged in response to static electricity caused by friction. For example, when a liquid flows through a tube, the tube can become negatively charged, while the liquid can become positively charged. For instance, if a fluid channel circulates a liquid from a liquid discharge head, and fluororesin is used as the material for the fluid channel, the liquid is more likely to become negatively charged.

[0008] When charged liquid is supplied to a liquid dispensing head and droplets of liquid are discharged from the head, liquids with the same polarity repel each other, reducing the accuracy of the liquid's impact point on the substrate.

[0009] Furthermore, if the substrate onto which the liquid impacts is charged and has the same polarity as the liquid, the liquid and substrate will repel each other, reducing the accuracy of the liquid's impact point on the substrate. If the substrate is charged with the opposite polarity to the liquid, and there is an in-plane distribution of charge, the liquid will be affected by the in-plane distribution of charge, raising concerns that the accuracy of the liquid's impact point on the substrate will decrease.

[0010] The inventions described in Patent Documents 1-3 all fail to consider the charging of ink caused by contact between the tube used as an ink channel and the ink, and thus have the aforementioned problems.

[0011] This invention has been made in view of these circumstances, and aims to provide a liquid discharge system that suppresses the decrease in impact position accuracy caused by the charging of liquid.

[0012] A liquid discharge system according to a first aspect of the present disclosure is a liquid discharge head having a fluid path substrate on which a fluid path is formed, wherein the fluid path comprises a fluid pump chamber, a pump chamber communicating fluid path fluidly connected to the fluid pump chamber, and a nozzle fluidly connected to the pump chamber communicating fluid path, the nozzle comprises a liquid discharge head having a nozzle opening formed at its end for discharging liquid, and a liquid supply device for supplying liquid to the liquid discharge head, the liquid supply device comprising a first tank for storing liquid, and a first flow path member connected to the first tank and the liquid discharge head, wherein the material of the part of the first flow path member that comes into contact with the liquid is made of a non-fluororesin.

[0013] According to the liquid discharge system of the first aspect of this disclosure, a non-fluororesin is applied to the material of the portion of the first flow channel member that comes into contact with the liquid. This suppresses static electricity generated by contact between the first flow channel member and the liquid, thereby suppressing a decrease in the accuracy of the projectile's impact point caused by the static electricity of the liquid.

[0014] In the liquid discharge system according to the second embodiment, the material of the first flow channel member may be at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

[0015] A liquid discharge system according to a third embodiment is a liquid discharge system according to a first embodiment in which the first flow channel member includes a tube structure, and the material of the inner wall of the tube structure may be at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

[0016] A liquid discharge system according to the fourth embodiment may include a first static elimination support device that eliminates static electricity in at least one of the first flow channel member and the space in which the first flow channel member is arranged, in addition to the liquid discharge system according to any one of the first to third embodiments.

[0017] In the liquid discharge system according to the fifth embodiment, the first static elimination support device may be at least one of a humidifier and a static elimination blower, as described in the liquid discharge system according to the fourth embodiment.

[0018] The liquid discharge system according to the sixth embodiment may include, in any one embodiment of the first to fifth embodiments, a second tank for containing the liquid recovered from the liquid discharge head, and a second flow channel member connected to the second tank and the liquid discharge head, wherein the material of the part that comes into contact with the liquid is made of a non-fluororesin.

[0019] In the liquid discharge system according to the seventh embodiment, the material of the second flow channel member may be at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide, as is the case in the liquid discharge system according to the sixth embodiment.

[0020] The liquid discharge system according to the eighth embodiment is the liquid discharge system according to the sixth embodiment, wherein the second flow channel member includes a tube structure, and the material of the inner wall of the tube structure may be at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

[0021] The liquid discharge system according to the ninth embodiment may include, in any one embodiment of the sixth to eighth embodiments, a second static elimination support device for eliminating static electricity in at least one of the second flow channel member and the space in which the second flow channel member is arranged.

[0022] In the liquid discharge system according to the tenth embodiment, the second static elimination support device may be at least one of a humidifier and a static elimination blower, as described in the liquid discharge system according to the ninth embodiment.

[0023] The liquid discharge system according to the 11th embodiment is a liquid discharge system according to any one of the sixth to tenth embodiments, comprising a third flow channel member connecting a first tank and a second tank, wherein the material of the part of the third flow channel member that comes into contact with the liquid may be a non-fluororesin.

[0024] In the liquid discharge system according to the 12th embodiment, the material of the third flow channel member may be at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide, as is the case with the liquid discharge system according to the 11th embodiment.

[0025] The liquid discharge system according to the 13th embodiment is the liquid discharge system according to the 11th embodiment, wherein the third flow channel member includes a tube structure, and the material of the inner wall of the tube structure may be at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

[0026] A liquid discharge system according to the 14th embodiment may include a third static elimination support device for eliminating static electricity in at least one of the third flow channel member and the space in which the third flow channel member is located, in addition to the liquid discharge system according to any one of the 11th to 13th embodiments.

[0027] In the liquid discharge system according to the 15th embodiment, the third static elimination support device may be at least one of a humidifier and a static elimination blower, as described in the liquid discharge system according to the 14th embodiment.

[0028] The liquid dispensing system according to the 16th embodiment is a liquid dispensing system according to any one embodiment from the 1st to the 15th embodiment, in which ultraviolet-curable ink may be applied as the liquid.

[0029] The liquid discharge system according to the 17th embodiment is a liquid discharge system according to any one embodiment from the 1st to the 15th embodiment, in which the liquid discharge head may be equipped with a fourth flow channel member to which a non-fluororesin is applied as the material of the part that comes into contact with the liquid.

[0030] The liquid discharge system according to the 18th aspect is the liquid discharge system of the 17th aspect, and at least any one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide may be applied to the material of the fourth flow path member.

[0031] The liquid discharge system according to the 19th aspect is the liquid discharge system of the 17th aspect, and the fourth flow path member includes a tube structure, and at least any one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide may be applied to the material of the inner wall of the tube structure.

[0032] The liquid discharge system according to the 20th aspect is the liquid discharge system of any one of the 1st aspect to the 19th aspect, and the non-fluorine resin does not contain fluorine having a perfluoroalkyl structure or a polyfluoroalkyl structure as a partial structure.

[0033] The liquid discharge system according to the 21st aspect is the liquid discharge system of any one of the 1st aspect to the 20th aspect, and a liquid repellent layer is formed on the ejection surface where the nozzle opening is formed, and the liquid repellent layer is (L-Y-) k Si-(O-*) 4-k and has a partial structure represented by, L is a hydrocarbon group, Y is a single bond or a divalent linking group not containing a fluorine atom, k is an integer of 1 or more and 3 or less, and * means a bond with another structure. It may be a liquid repellent layer.

[0034] The liquid discharge system according to the 22nd aspect is the liquid discharge system of the 21st aspect, and the thickness of the liquid repellent layer may be 50 nanometers or less.

[0035] According to the present invention, a non-fluorine resin is applied to the material of the portion of the first flow path member that contacts the liquid. Thereby, charging caused by the contact between the first flow path member and the liquid is suppressed, and a decrease in landing accuracy caused by the charging of the liquid is suppressed.

[0036] FIG. 1 is an overall configuration diagram of a printing system according to the first embodiment. FIG. 2 is a perspective view of an inkjet head illustrated in FIG. 1. FIG. 3 is a block diagram showing a configuration example of an ink supply system applied to the printing system illustrated in FIG. 1. FIG. 4 is a perspective view showing a structural example of a head module. FIG. 5 is a cross-sectional view showing a structural example of a head module. FIG. 6 is a perspective view of a tube applied to an ink flow path. FIG. 7 is a schematic diagram showing a configuration example of a printing system according to the second embodiment.

[0037] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification, the same reference numerals are assigned to the same components, and redundant descriptions are omitted as appropriate. Further, when a plurality of components are exemplified in the following embodiments, it can be interpreted as including at least one of the plurality of components.

[0038] [Overall Configuration of Printing System] FIG. 1 is an overall configuration diagram of a printing system according to the first embodiment. The printing system 10 illustrated in the figure is a printing system to which a single-pass method is applied, and for example, a color image is printed on a non-permeable medium 1 using ultraviolet curable ink. The printing system 10 may print a black-and-white image.

[0039] In the single-pass method, the printing device 16 and the medium 1 to be printed are relatively moved in one direction only once, and printing is performed on the entire printing area of the medium 1. The arrow line illustrated in FIG. 1 represents the medium conveyance direction when the medium 1 is moved with respect to the fixedly arranged printing device 16.

[0040] A non-permeable medium is a medium having a property that an ink solvent does not penetrate into the inside of the medium or a part of the ink solvent remains on the surface of the medium. Examples of materials used for non-permeable media include ONY, OPP, and PET. Note that ONY is an abbreviation for Oriented Nylon, OPP is an abbreviation for Oriented PolyPropylene, and PET is an abbreviation for PolyEthylene Terephthalate.

[0041] Medium 1 may be a transparent film used for flexible packaging. Flexible packaging may be packaging that uses a material that deforms according to the shape of the article being packaged. Transparent means that the visible light transmittance is 30% or more and 100% or less, and that the visible light transmittance is 70% or more and 100% or less. Medium 1 may also be referred to as a printing medium, printing media, or substrate.

[0042] The printing system 10 comprises a media supply device 12, a pre-processing device 14, a printing device 16, a post-processing device 18, an inspection device 20, and a printed material storage device 22. The printing system 10 is equipped with a transport device 24 that performs roll-to-roll media transport. In roll-to-roll media transport, the media 1 drawn from the feed roll passes through a media transport path along the media transport direction from the media supply device 12 to the printed material storage device 22 and is wound onto a take-up roll. Multiple pass rollers that support the media 1 are arranged in the media transport path. Figure 1 shows the portion of the transport device 24 that is located in the printing device 16, and the portion of the transport device 24 located in other devices is not shown.

[0043] [Example of Media Supply Device Configuration] The media supply device 12 includes a feed roll on which an unprinted medium 1 is wound. The feed roll includes a reel that is rotatably supported. Note that the illustration of the feed roll and reel is omitted.

[0044] [Example of Preprocessing Device Configuration] The preprocessing device 14 is positioned downstream of the media supply device 12 in the media transport direction. The preprocessing device 14 performs preprocessing on the unprinted media 1. Examples of preprocessing include temperature adjustment of the media 1 and modification of the printing surface 1A of the media 1. The modification of the printing surface may be a coating treatment on the printing surface. The printing system 10 may not be equipped with the preprocessing device 14, and the media 1 may be transported from the media supply device 12 to the printing device 16.

[0045] [Example of Printing Apparatus Configuration] The printing apparatus 16 is positioned downstream of the preprocessing device 14 in the media transport direction. The printing apparatus 16 is equipped with inkjet heads 30K, 30C, 30M, 30Y, and 30W, which eject inks of black, cyan, magenta, yellow, and white, respectively.

[0046] The printing apparatus 16 may be equipped with an inkjet head 30 that ejects special color inks such as violet, green, and orange. The printing apparatus 16 may also be equipped without an inkjet head 30W.

[0047] The same configuration applies to inkjet heads 30K, etc. Hereafter, unless it is necessary to distinguish between inkjet heads 30K, etc., they will be referred to as inkjet head 30.

[0048] The ink ejected from the inkjet head 30 is an ultraviolet-curable ink that hardens when exposed to ultraviolet light. The ultraviolet-curable ink preferably contains a polymerizable compound. Details of the ultraviolet-curable ink will be described later. Note that ultraviolet-curable ink may be referred to as UV ink, using the abbreviation of UltraViolet, the English term for ultraviolet light.

[0049] An inkjet head 30K, which ejects color inks excluding white ink, prints a color image on the printing surface 1A of the medium 1. An inkjet head 30W, which ejects white ink, prints the white background image of the color image. The inkjet head 30W may print a portion of the color image. Note that the inkjet head 30 is an example of a liquid ejection head in this disclosure.

[0050] The printing apparatus 16 includes a scanner 32. The scanner 32 includes an image sensor that captures a test image printed on the printing surface 1A of the medium 1 and generates the capture data of the test image. Examples of image sensors include CCD image sensors and CMOS image sensors. CCD is an abbreviation for Charge Coupled Device, and CMOS is an abbreviation for Complementary Metal Oxide Semiconductor.

[0051] The printing device 16 monitors the ejection status of the inkjet head 30 based on the captured data of the test image. In other words, the printing device 16 detects ejection abnormalities in the inkjet head 30. If an ejection abnormality of the inkjet head 30 is detected, the printing device 16 performs a correction process.

[0052] The printing apparatus 16 includes a plurality of pass rollers 34 and a tension pickup 36 provided on the transport device 24. The printing apparatus 16 may also include a tension roller for adjusting the tension applied to the medium 1.

[0053] The pass roller 34 extends in the media width direction and has a length corresponding to the total length of the media 1 in the media width direction. The media width direction is perpendicular to the media transport direction and represents the direction parallel to the support surface 1B of the media 1. The pass roller 34 is rotatably supported with the media width direction as the direction of its axis of rotation. The pass roller 34 supports the support surface 1B of the media 1.

[0054] In this context, "parallel" may include lines that are not strictly parallel but can be considered effectively parallel. Similarly, "orthogonal" may include lines that are not strictly orthogonal but can be considered effectively orthogonal.

[0055] The tension pickup 36 detects the tension applied to the medium 1. The transport device 24 may adjust the tension applied to the medium 1 based on the detection signal from the tension pickup 36.

[0056] [Example of Post-Processing Device Configuration] The post-processing device 18 is positioned downstream of the printing device 16 in the media transport direction. The post-processing device 18 irradiates the ink adhering to the printed surface 1A of the medium 1 with ultraviolet light to cure the ink and fix the color image to the printed surface 1A of the medium 1.

[0057] The post-processing device 18 includes an ultraviolet light source. The ultraviolet light source may be configured such that multiple ultraviolet LEDs are arranged in a single row or in a two-dimensional arrangement. LED is an abbreviation for Light-Emitting Diode.

[0058] The ultraviolet light source may be provided inside the printing apparatus 16. For example, the ultraviolet light source may be positioned downstream of the inkjet head 30W in the media transport direction. Alternatively, an ultraviolet light source may be positioned downstream of each inkjet head 30K, etc., in the media transport direction.

[0059] When water-based ink is applied to the printing apparatus 16, the post-processing apparatus 18 may be a drying apparatus equipped with a heater and a blower to dry the water-based ink adhering to the printing surface 1A of the medium 1. The post-processing apparatus 18 may be equipped with a plurality of processing apparatuses that perform different processes.

[0060] [Example of Inspection Device Configuration] The inspection device 20 is positioned downstream of the post-processing device 18 in the media transport direction. The inspection device 20 performs inspection of printed materials on which a color image is printed on the printed surface 1A of the medium 1. The inspection device 20 includes an illumination device that irradiates illumination light onto the printed material, and an imaging device that photographs the printed material. The inspection device 20 photographs the printed material using the imaging device and generates imaging data of the printed material.

[0061] The inspection device 20 determines whether or not there are defects in the printed material based on the photographic data of the printed material. The inspection device 20 may mark the defective printed material that has been determined to have defects, thereby separating the good printed material from the defective printed material.

[0062] [Example of Printed Material Handling Device Configuration] The printed material handling device 22 is positioned downstream of the inspection device 20 in the media transport direction. The printed material handling device 22 is equipped with a winding roll for winding up the medium 1 containing the printed material.

[0063] In this embodiment, a conveying device 24 that conveys the medium 1 using a roll-to-roll method is exemplified, but the conveying device 24 may be configured to convey a single sheet of medium using a belt conveying method or the like. When conveying a single sheet of medium, a device for transferring the medium between each device may be provided.

[0064] A media supply device 12 that uses sheet-fed media includes a supply tray for storing stacked media, and a pickup device for taking out media one sheet at a time from the supply tray.

[0065] A printed material storage device 22 that uses sheet-fed media includes a storage tray for storing stacked sheet-fed printed materials. The printed material storage device 22 that uses sheet-fed media may also include a collection tray for collecting good printed materials and a collection tray for collecting defective printed materials.

[0066] Other components of the printing system 10, besides the inkjet head 30, may be the same as those of conventionally known configurations. For example, various components can be found in International Publication No. 2017 / 073526 and Japanese Patent Publication No. 2022-049414. The printing system 10 is an example of the liquid ejection system of this disclosure.

[0067] Figure 1 illustrates a single-pass printing system 10 to which a line-type inkjet head 30 is applied, but the printing system 10 may be serial. An example of a serial printing system is the inkjet recording device described in Japanese Patent Application Publication No. 2017-81008.

[0068] The inkjet recording device described in the publication includes a carriage that moves back and forth in the media width direction, equipped with multiple inkjet heads corresponding to each of the multiple colors, a semi-curing light source, and a full-curing light source.

[0069] A serial inkjet printer reciprocates the carriage in the media width direction to print in that direction, then moves the media in the media transport direction to print in the next printing area in the media width direction, and repeats this operation to print on the entire surface of the media.

[0070] The semi-curing light source irradiates the ink with ultraviolet light immediately after it hits the medium, causing it to partially harden. The hardening light source then irradiates the partially hardened ink with ultraviolet light stronger than that emitted from the semi-curing light source, causing the ink to fully harden.

[0071] It should be noted that the serial inkjet recording device described in this publication is just one example, and it is possible to add, delete, or change components, for example, in a configuration that does not include a semi-curing light source or a fully curing light source.

[0072] [Electrical Configuration of the Printing System] The printing system 10 includes a control device to which a computer equipped with a processor and memory is applied. The control device realizes various functions of the printing system 10 by having the processor execute a program stored in memory.

[0073] Each of the various devices constituting the printing system 10, such as the printing device 16, may be equipped with a control device. The control device equipped in the printing device 16, etc., is a computer that includes a processor and memory, and in which the processor executes programs stored in the memory.

[0074] [Example of Inkjet Head Configuration] Figure 2 is a perspective view of the inkjet head shown in Figure 1. The inkjet head 30 shown in Figure 2 has a cover 40 attached to it. Inside the cover 40, there is an ink channel through which the ink passes.

[0075] The inkjet head 30 has a structure in which, for example, a plurality of head modules 42 are arranged along the longitudinal direction of the inkjet head 30. The plurality of head modules 42 are integrally supported using a head module support member 44.

[0076] In Figure 2, the longitudinal direction of the inkjet head 30 is shown as the x-direction. The y-direction shown in the same figure is the short-direction of the inkjet head 30. When the inkjet head 30 is positioned at the printing position for printing on the medium 1, the longitudinal direction of the inkjet head 30 corresponds to the medium width direction, and the short-direction of the inkjet head 30 corresponds to the medium transport direction.

[0077] The inkjet head 30 includes an adjustment mechanism for adjusting the position of each of the multiple head modules 42. The adjustment mechanism may include an x-direction position adjustment mechanism for adjusting the x-direction position of each of the multiple head modules 42. The adjustment mechanism may also include a rotation angle adjustment mechanism for adjusting the rotation angle in the xy-plane, which is parallel to the x-direction and the y-direction, respectively.

[0078] Figure 2 illustrates an inkjet head 30 equipped with multiple head modules 42, but the inkjet head 30 may also be configured to include one long head module having a total length corresponding to the total length of the medium 1 in the medium width direction.

[0079] [Example of Ink Supply System Configuration] Figure 3 is a block diagram illustrating an example of an ink supply system configuration applied to the printing system shown in Figure 1. Figure 3 also shows the ink flow path structure provided in the inkjet head 30.

[0080] The ink supply device 100 includes a supply tank 114, a supply channel 116, a recovery channel 118, a recovery tank 120, and an inter-tank channel 122. The inkjet head 30 communicates with the supply tank 114 via the supply channel 116. The inkjet head 30 also communicates with the recovery tank 120 via the recovery channel 118. The supply tank 114 and the recovery tank 120 communicate with each other via the inter-tank channel 122.

[0081] The supply channel 116 comprises a supply channel valve 130, a supply channel pump 132, a supply channel filter 134, and a supply channel sub-tank 136. The supply channel valve 130 is a control valve that opens and closes in response to a control signal. The supply channel pump 132 applies pressure to the ink flowing through the supply channel 116 in a direction toward the inkjet head 30. The supply channel pump 132 may be a tube pump.

[0082] The ink supply device 100 opens the supply channel valve 130 and operates the supply channel pump 132 to supply ink from the supply tank 114 to the inkjet head 30.

[0083] The supply channel filter 134 captures the thickened components of the ink and any foreign matter contained in the ink, removing these foreign matter particles from the ink. The mesh size applied to the supply channel filter 134 is determined according to the ink conditions, such as the type of ink.

[0084] The supply channel sub-tank 136 suppresses pressure fluctuations in the ink supplied to the inkjet head 30. Pressure fluctuations may occur in the ink discharged from the supply channel pump 132 due to pulsation of the supply channel pump 132, etc. The supply channel sub-tank 136 temporarily stores the ink supplied to the inkjet head 30 and supplies the inkjet head 30 with a constant volume of ink per unit time.

[0085] The recovery channel 118 includes a recovery channel sub-tank 140. The recovery channel sub-tank 140 suppresses pressure fluctuations of the ink flowing through the recovery channel 118. The recovery channel sub-tank 140 communicates with the supply channel sub-tank 136 via an inter-sub-tank channel 142. The inter-sub-tank channel 142 is equipped with an inter-sub-tank channel valve 144.

[0086] The inter-tank passage 122 includes an inter-tank pump 124 and an inter-tank passage valve 126. The inter-tank pump 124 may be a tube pump. The inter-tank passage valve 126 may be a three-way valve.

[0087] In other words, the inter-tank flow path 122 is branched using the inter-tank flow path valve 126 and communicates with the recovery tank 120 and the supply flow path 116. The inter-tank flow path valve 126 switches between flowing ink from the inter-tank flow path 122 to the recovery tank 120 or flowing ink from the inter-tank flow path 122 to the supply flow path 116.

[0088] The supply channel sub-tank 136 comprises a liquid chamber 150, a flexible membrane 152, a gas chamber 154, and an atmospheric opening chamber 156. The liquid chamber 150 includes an ink inlet connected to the supply channel 116 on the supply tank 114 side, and an ink outlet connected to the supply channel 116 on the inkjet head 30 side. Note that the ink inlet and ink outlet are not shown in the illustration.

[0089] The gas chamber 154 is in communication with the atmospheric opening chamber 156. The atmospheric opening chamber 156 is equipped with an atmospheric opening valve, which is configured to allow switching between atmospheric opening and atmospheric shutoff. Note that the atmospheric opening valve is not shown in the illustration.

[0090] In the supply channel subtank 136, the flexible membrane 152 separating the liquid chamber 150 and the gas chamber 154 flexes and deforms in accordance with the volume of ink contained in the liquid chamber 150. This suppresses pressure fluctuations of the ink flowing out from the supply channel subtank 136.

[0091] The recovery channel subtank 140 has the same structure as the supply channel subtank 136 and includes a liquid chamber 160, a flexible membrane 162, a gas chamber 164, and an atmospheric opening chamber 166. The recovery channel subtank 140 operates in the same way as the supply channel subtank 136 to suppress pressure fluctuations of the ink flowing through the recovery channel 118.

[0092] The inkjet head 30 includes an ink flow path structure comprising a supply manifold 170, a supply head flow path 172, a supply head valve 174, a recovery head flow path 176, a recovery head valve 178, a recovery manifold 180, a circulation flow path 182, and a circulation flow path valve 184.

[0093] The supply head channel 172, supply head valve 174, recovery head channel 176, and recovery head valve 178 are provided for each of the multiple head modules 42. In Figure 3, the reference numerals for the supply head channel 172, etc., that communicate with any one of the multiple head modules 42 are shown, while the reference numerals for the supply head channel 172, etc., that communicate with other head modules 42 are omitted.

[0094] The supply manifold 170 communicates with each of the multiple head modules 42 via one of the multiple supply head passages 172. The supply head passages 172 are connected to the supply ports 42A of the head modules 42.

[0095] The supply manifold 170 temporarily stores the ink that flows into the inkjet head 30. The physical properties of the ink stored in the supply manifold 170, such as pressure and temperature, are controlled.

[0096] Each of the multiple supply head passages 172 is equipped with a supply head valve 174. The supply head valve 174 is a control valve whose opening and closing is controlled based on a control signal.

[0097] The recovery manifold 180 communicates with each of the multiple head modules 42 via one of the multiple recovery head passages 176. The recovery head passages 176 are connected to the recovery ports 42B of the head modules 42.

[0098] The recovery manifold 180 temporarily stores the ink that flows out from the inkjet head 30. The physical properties of the ink stored in the recovery manifold 180, such as pressure and temperature, are controlled.

[0099] Each of the multiple recovery head flow paths 176 is equipped with a recovery head valve 178. The recovery head valve 178 is a control valve whose opening and closing is controlled based on a control signal.

[0100] The circulation channel 182 connects the supply manifold 170 and the recovery manifold 180. The circulation channel 182 is equipped with a circulation channel valve 184. The circulation channel valve 184 is a control valve whose opening and closing is controlled based on a control signal.

[0101] The ink flow path structure provided in the inkjet head 30, such as the supply manifold 170 shown in Figure 3, may be located outside the inkjet head 30 and may be a component of the ink supply device 100.

[0102] Figure 3 illustrates an inkjet head 30 equipped with an ink circulation structure including a recovery manifold 180, but the inkjet head 30 may also be configured without an ink circulation structure.

[0103] On the other hand, in an inkjet head 30 equipped with an ink circulation structure, the charge contained in the charged ink flows out to the outside of the inkjet head 30 due to the outflow of ink from the inkjet head 30. This suppresses the charging of the inkjet head 30. Note that the ink supply device 100 is an example of a liquid supply device of this disclosure.

[0104] [Example of Head Module Structure] Figure 4 is a perspective view showing an example of the structure of a head module. Figure 4 shows any one of the multiple head modules 42 shown in Figure 2. The head module 42 is mounted on the bracket 200 such that the ejection surface 42C, which has nozzle openings for ejecting ink, is exposed.

[0105] Multiple nozzle openings are arranged in a strip-shaped nozzle arrangement area in the central part of the discharge surface 42C. The nozzle arrangement area functions as the actual discharge surface. The nozzle openings are not shown in Figure 4. The nozzle openings are denoted by reference numeral 310 and are shown in Figure 5.

[0106] The bracket 200, to which the head module 42 is attached, is mounted to the clamp assembly 202. The clamp assembly 202 is equipped with an adjustment mechanism for adjusting the position of the head module 42 mounted on the bracket 200.

[0107] The head module 42 includes an ink supply unit 204 which is equipped with an ink supply chamber and an ink circulation chamber. The ink supply chamber and ink circulation chamber are not shown in the illustration.

[0108] The ink supply chamber is fitted with a tube 206 that functions as the supply head channel 172 as shown in Figure 3. The ink circulation chamber is fitted with a tube 206 that functions as the recovery head channel 176. The tube 206 that functions as the supply head channel 172 and the tube 206 that functions as the recovery head channel 176 may have the same structure and shape.

[0109] A flexible circuit board 208 is attached to the head module 42. Electrical wiring is formed on the flexible circuit board 208 to transmit the drive voltage supplied to the piezoelectric element provided in the head module 42. In Figure 4, two flexible circuit boards 208 are attached to one head module 42. The piezoelectric element is denoted by reference numeral 330 and is shown in Figure 5.

[0110] The head module 4 includes a substrate that functions as an ink ejection structure for ejecting ink from the nozzle opening. The substrate may have a structure in which multiple silicon substrates processed using a semiconductor process are stacked.

[0111] [Specific Example of Ink Discharge Structure Provided in a Head Module] Figure 5 is a cross-sectional view showing an example of the structure of a head module. Figure 5 shows an ink discharge structure 300 corresponding to one nozzle opening 310. The ink discharge structure 300 comprises a fluid passage substrate 302 and a nozzle substrate 304, and has a structure in which the nozzle substrate 304, on which the nozzle opening 310 is formed, is joined to the fluid passage substrate 302, on which the fluid passage is formed, by applying adhesive or the like. A liquid-repellent layer 306 is formed on the side of the nozzle substrate 304 on which the ink is discharged.

[0112] Other layers besides the liquid-repellent layer 306 may be formed on the nozzle substrate 304. Preferably, the liquid-repellent layer 306 is located on the outermost surface of the nozzle substrate 304. That is, the liquid-repellent layer 306 is the outermost layer of the layers formed on the nozzle substrate 304. The side of the liquid-repellent layer 306 from which the ink is ejected functions as the effective ejection surface 42C.

[0113] The fluid path substrate 302 has a descending channel 312, a fluid pump chamber 314, individual supply channels 315, a common supply channel 316, an individual circulation channel 318, and a common circulation channel 320. An internal protective film 322 is formed on the inner walls of the descending channel 312 and the fluid pump chamber 314, etc.

[0114] The descending passage 312 is a passage that connects the nozzle opening 310 to the fluid pump chamber 314. The descending passage 312 is an example of a pump chamber communication fluid passage that is fluidly connected to the fluid pump chamber of the present disclosure.

[0115] The fluid pump chamber 314 communicates with the common supply channel 316 via the individual supply channel 315. The common supply channel 316 communicates with the tube 206, which functions as the supply head channel 172 shown in Figure 4, via the ink supply chamber.

[0116] Ink supplied to the common supply channel 316 via tube 206, which functions as a supply head channel 172, and the ink supply chamber is sent to the fluid pump chamber 314 via individual supply channels 315. In the fluid pump chamber 314, discharge pressure is applied to the ink. The ink, with discharge pressure applied, is discharged from the nozzle opening 310 via the descending channel 312.

[0117] The descending channel 312 communicates with the common circulation channel 320 via the individual circulation channel 318. The common circulation channel 320 communicates with the tube 206, which functions as the recovery head channel 176 shown in Figure 4, via the ink circulation chamber.

[0118] Ink that is not ejected from the nozzle opening 310 is sent to the recovery manifold 180 shown in Figure 3 via tube 206, which functions as an individual circulation channel 318, a common circulation channel 320, and a recovery head channel 176.

[0119] The ink ejection structure 300 includes a piezoelectric element 330. The piezoelectric element 330 is positioned on the side of the diaphragm 332, which forms the ceiling surface of the fluid pump chamber 314, that is opposite to the fluid pump chamber 314.

[0120] The piezoelectric elements 330 are arranged to correspond to each of the multiple fluid pump chambers 314 provided in the head module 42. The piezoelectric elements 330 include an upper electrode and a lower electrode. The upper electrode is sometimes called an individual electrode, and the lower electrode is sometimes called a common electrode.

[0121] The upper electrode is a patterned electrode for each of the multiple piezoelectric elements 330, and the lower electrode is an electrode that provides a common reference potential for the multiple piezoelectric elements. The upper and lower electrodes are electrically connected to electrical wiring formed on the flexible substrate 208 shown in Figure 4.

[0122] Figure 5 illustrates a piezojet system that applies ejection pressure to the ink by utilizing the deflection deformation of the piezoelectric element 330. The method for applying ejection pressure to the ink may be a thermal system or an electrostatic system.

[0123] The nozzle substrate 304 may be a silicon substrate. The nozzle substrate 304 may be a single-crystal silicon substrate or a polycrystalline silicon substrate. The nozzle substrate 304 has a plurality of through holes formed therein that function as nozzles. One end of the through holes that ejects ink functions as a nozzle opening 310. Dry etching may be used to form the through holes.

[0124] From the viewpoint of controlling ink ejection, the shape of the nozzle substrate 304 side of the descending flow path 312 and the shape of the through hole formed in the nozzle substrate 304 are preferably such that the diameter becomes relatively smaller in the direction from which the ink is ejected.

[0125] The diameter of the nozzle opening 310 on the nozzle substrate 304 is preferably 10 micrometers or more and 100 micrometers or less. The diameter of the nozzle opening 310 is appropriately defined according to the specifications of the inkjet head 30.

[0126] The thickness of the nozzle substrate 304 is preferably 10 micrometers or more and 100 micrometers or less, corresponding to the length of the through hole. More preferably, the thickness of the nozzle substrate 304 is 20 micrometers or more and 60 micrometers or less.

[0127] The liquid-repellent layer 306 formed on the nozzle substrate 304 suppresses the adhesion of ink mist and foreign matter such as dust to the ejection surface 42C, thereby stabilizing the ink ejection state. The liquid-repellent layer 306 also facilitates the removal of ink mist and other foreign matter that adheres to the ejection surface 42C.

[0128] Conventional liquid-repellent layers formed on the discharge surface 42C may use fluororesin, raising concerns about ink charging due to contact between the liquid-repellent layer 306 and the ink. In this embodiment, a non-fluorine material is used for the liquid-repellent layer 306. The internal protective film 322 may also be made of a non-fluorine material.

[0129] Here, "fluorine materials not included in non-fluorine materials" refers to materials having a perfluoroalkyl structure or a polyfluoroalkyl structure as a substructure. Other fluorine-containing materials may be added to non-fluorine materials to the extent that they do not impair the effects resulting from the use of non-fluorine materials.

[0130] From the viewpoint of maintaining alkali resistance of the discharge surface 42C, the nozzle substrate 304 may have a first intermediate layer containing silicon dioxide and a liquid-repellent layer 306 formed on the discharge surface 42C. When the first intermediate layer and the liquid-repellent layer 306 are formed, they are formed in the order of the first intermediate layer and the liquid-repellent layer 306 starting from the nozzle substrate 304.

[0131] When the inkjet head 30 is used for a long period of time, if an alkaline liquid penetrates the liquid-repellent layer 306 formed on the ejection surface 42C of the nozzle substrate 304, the alkali resistance of the ejection surface 42C is maintained due to the presence of the first intermediate layer.

[0132] The thickness of the first intermediate layer is preferably 0.3 nanometers or more and 120 nanometers or less, and more preferably 10 nanometers or more and 100 nanometers or less. In particular, when the thickness of the first intermediate layer is 0.3 nanometers or more and 120 nanometers or 10 nanometers or more and 100 nanometers or less, the adhesion between the first intermediate layer and the liquid-repellent layer 306 is relatively increased, and the wipe resistance and alkali resistance of the discharge surface 42C are improved.

[0133] Furthermore, from the viewpoint of relatively improving the alkali resistance of the discharge surface 42C, it is preferable that the nozzle substrate 304 has a second intermediate layer, a first intermediate layer, and a liquid-repellent layer 306 formed on the discharge surface 42C in the order of the second intermediate layer, the first intermediate layer, and the liquid-repellent layer 306, with the compound containing elements from Group 3 to Group 6 being formed on the nozzle substrate 304.

[0134] Examples of compounds containing elements from Group 3 to Group 6 include tantalum oxide, zirconium oxide, titanium oxide, and hafnium oxide. The elements applied to the second intermediate layer are preferably tantalum oxide, zirconium oxide, and hafnium oxide.

[0135] The thickness of the second intermediate layer is preferably 3 nanometers or more and 70 nanometers or less, and more preferably 10 nanometers or more and 50 nanometers or less. Here, it is preferable that neither the first intermediate layer nor the second intermediate layer contains an organofluororesin.

[0136] The contact angle of the liquid-repellent layer 306 with respect to water is preferably 60 degrees or more, more preferably 70 degrees or more, and even more preferably 80 degrees or more. The formation of the liquid-repellent layer 306 on the outermost surface of the nozzle substrate 304 provides excellent wipe resistance of the discharge surface 42C.

[0137] The liquid-repellent layer 306 has a substructure represented by the following formula 1: (L-Y-) k Si-(O-*) 4-k ...Formula 1

[0138] In formula 1, L is a hydrocarbon group, Y is a single bond or a divalent linking group that does not contain a fluorine atom, k is an integer between 1 and 3, and * indicates the bond position with other structures.

[0139] The hydrocarbon group represented by L in Formula 1 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The hydrocarbon group is preferably an aliphatic hydrocarbon group, and more preferably an alkyl group. The alkyl group may be a linear alkyl group, a branched alkyl group, or a cyclic alkyl group.

[0140] The number of carbon atoms in the hydrocarbon group is preferably 1 or more and 30 or less, more preferably 1 or more and 20 or less. The hydrocarbon group may have a substituent. The substituent preferably does not contain a fluorine atom.

[0141] In Formula 1, the divalent linking group that does not contain a fluorine atom represented by Y includes, for example, at least one selected from the group consisting of -O-, -C(=O)-, and NR-, in combination with a hydrocarbon group. R represents a hydrogen atom or a hydrocarbon group. However, the linking portion of Y with L is not a hydrocarbon group.

[0142] When Y is a divalent linking group, examples of Y include: * 1 -O-C(=O)-(hydrocarbon group)-C(=O)-O-(hydrocarbon group)-* 2 * 1 -O-(hydrocarbon group)-O-(hydrocarbon group)-* 2 * 1 -C(=O)-NH-(hydrocarbon group)-* 2 * 1 -NH-C(=O)-NH-(hydrocarbon group)-* 2 * 1 -O-C(=O)-NH-(hydrocarbon group)-* 2 etc. * 1 means the bonding position with L, and * 2 means the bonding position with Si.

[0143] The hydrocarbon group contained in the divalent linking group that does not contain a fluorine atom represented by Y in Formula 1 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Among the above hydrocarbon groups, an aliphatic hydrocarbon group is preferred, and an alkylene group is more preferred. The alkylene group may be a linear alkylene group, a branched alkylene group, or a cyclic alkylene group. The linear alkylene group is preferred.

[0144] From the viewpoint of improving the durability of the liquid-repellent layer 306 by aggregating hydrocarbon groups with each other, Y is preferably a single bond. Also, from the viewpoint of ejection reliability, k is preferably 3 or more.

[0145] The substructure represented by formula 1 above is preferably formed using a compound represented by the following formula 11 or formula 12: L-Y-SiX3 ...Formula 11 L-Y-SiNR 11 NSi-Y-L ...Formula 12 In Formula 11, L is a hydrocarbon group, Y is a single bond or a divalent linking group that does not contain a fluorine atom, and X is independently a hydrolyzable group. Compounds represented using Formula 11 and compounds represented using Formula 12 may be used in combination, and compounds other than those represented using Formula 11 and Formula 12 that do not contain a fluorine atom may be used in combination, to the extent that the effects resulting from the use of the above compounds are not impaired.

[0146] In formula 12, L is independently a hydrocarbon group, Y is independently a single bond or a divalent linking group that does not contain a fluorine atom, and R 11 This is either a hydrogen atom or a methyl group.

[0147] A preferred embodiment of the hydrocarbon group represented by L in formulas 11 and 12 is the same as that of the hydrocarbon group represented by L in formula 1. A preferred embodiment of the fluorine-free divalent linking group represented by Y in formulas 11 and 12 is the same as that of the fluorine-free divalent linking group represented by Y in formula 1. In formulas 11 and 12, Y is preferably a single crystal.

[0148] Examples of hydrolyzable groups represented by X in formula 11 include halogen atoms, alkoxy groups, and acyloxy groups. Hydrolyzable groups are preferably halogen atoms or alkoxy groups, and more preferably alkoxy groups.

[0149] Examples of halogen atoms include chlorine atoms, bromine atoms, and iodine atoms. Chlorine atoms are preferred as the halogen atom. The alkoxy group is preferably an alkoxy group having 1 to 6 carbon atoms, and more preferably an alkoxy group having 1 to 3 carbon atoms. When the hydrolyzable group is an alkoxy group, the density of the liquid-repellent layer 306 is relatively improved, and the alkali resistance is also relatively improved.

[0150] A liquid-repellent layer 306 having a substructure represented by formula 1 can be obtained using a compound represented by formula 11 or formula 12. The liquid-repellent layer 306 may contain a hydrolysate of the compound represented by formula 11 or formula 12. The hydrolysate of the compound represented by formula 11 or formula 12 has Si-O-Si bonds, which can relatively improve the durability of the liquid-repellent layer 306.

[0151] The thickness of the liquid-repellent layer 306 is preferably 50 nanometers or less, and more preferably 0.5 nanometers or more and 40 nanometers or less. When the thickness of the liquid-repellent layer 306 is 50 nanometers or less, the curvature of the discharge is suppressed and the straightness of the discharge is improved.

[0152] [Example of tube structure] Figure 6 is a perspective view of a tube applied to an ink flow path. The figure shows the external appearance and internal structure of tube 400. The term "ink flow path" here refers to the supply flow path 116, recovery flow path 118, inter-tank flow path 122, supply head flow path 172, and recovery head flow path 176 shown in Figure 3.

[0153] The tube 400 has a triple-layer structure in which the tube structure 402 is covered with a first covering member 404, and the first covering member 404 is further covered with a second covering member 406. Figure 6 shows the triple-layer structure of the tube 400, but the tube 400 does not have to have a triple-layer structure.

[0154] The tube structure 402, which is the part of the tube 400 that comes into contact with the ink, is made of a fluorine-free non-fluororesin such as polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide. This suppresses the charging of the ink flowing through the tube 400, and reduces the supply of charged ink to the inkjet head 30. Suppressing the supply of charged ink to the inkjet head 30 can suppress the decrease in the accuracy of the inkjet head 30's target placement caused by ink charging.

[0155] The tube structure 402 may have an inner wall made of a non-fluorine material such as a non-fluoropolymer that comes into contact with the ink, and the entire tube structure 402 may be made of a non-fluorine material.

[0156] From the standpoint of suppressing the charging of the ink flowing through the tube 400, the materials of the first coating member 404 and the second coating member 406 may be non-fluorine materials or fluorine materials. If the entire material of the tube 400 is a non-fluorine material, it is also suitable for environments where the use of fluorine materials is restricted.

[0157] Polytetrafluoroethylene, used as a material for tubes applied to conventional ink channels, is a substance that tends to become negatively charged. Other examples of substances that tend to become negatively charged include vinyl chloride, polypropylene, polyethylene, polyurethane, polystyrene, polyester, ABS, rubber, nickel, and others.

[0158] In the triboelectric series, which shows the order of how easily substances become charged, polytetrafluoroethylene is the most easily negatively charged among the substances listed above, and the order of the substances listed above represents the order in which they are most easily negatively charged.

[0159] In the triboelectric series, substances that tend to become positively charged are, in order of increasing likelihood of becoming positively charged, air, asbestos, human hair or fur, glass, mica, wool, nylon, silk, aluminum, paper, and iron.

[0160] Non-fluorinated materials such as polypropylene, polyethylene, polyamide, and vinyl chloride are less prone to static charge than polytetrafluoroethylene in the triboelectric series. Polyimide, also a non-fluorinated material, is also less prone to static charge than polytetrafluoroethylene.

[0161] In other words, by using a non-fluorine material for the parts of the tube 400 that come into contact with the ink, such as the tube structure 402, the charging of the ink flowing through the tube 400 is suppressed. This suppresses a decrease in the ejection state caused by the charging of the ink. In particular, the supply head flow path 172 shown in Figure 3 is a flow path for ink supplied to the inkjet head 30, and the use of a tube 400 to which a non-fluorine material is applied is preferable in that it prevents charged ink from entering the inside of the inkjet head 30.

[0162] The tubes 400 applied to the supply channel 116, recovery channel 118, and inter-tank channel 122 shown in Figure 3 are examples of the first, second, and third channel members of this disclosure. The tubes 400 applied to the supply head channel 172, recovery head channel 176, and circulation channel 182 are examples of the fourth channel member of this disclosure. The supply tank 114 is an example of the first tank of this disclosure, and the recovery tank 120 is an example of the second tank of this disclosure.

[0163] [Specific Examples of Ink] The ink used in the printing system 10 shown in Figure 1, etc., preferably contains a polymerizable compound. Such preferred embodiments of ink are suitable as ultraviolet-curable inks.

[0164] The polymerizable compound is preferably at least one selected from the group consisting of (meth)acrylate compounds and N-vinyl compounds.

[0165] A preferred embodiment of the ink is one which comprises at least one selected from the group consisting of (meth)acrylate compounds and N-vinyl compounds, a photopolymerization initiator, and an organic solvent. A more preferred embodiment of the ink is one which comprises at least one selected from the group consisting of (meth)acrylate compounds and N-vinyl compounds, a photopolymerization initiator, an organic solvent, and a colorant.

[0166] [(Meth)acrylate compound] A (meth)acrylate compound means an acrylate compound or a methacrylate compound. A (meth)acryloyloxy group means an acryloyloxy group or a methacryloyloxy group.

[0167] In the (meth)acrylate compound, the number of (meth)acryloyloxy groups is not particularly limited, for example, 1 to 6, but 2 to 6 is preferred, 2 to 4 is more preferred, and 2 to 3 is even more preferred in terms of superior flexibility and alcohol resistance of the image layer.

[0168] The (meth)acrylate compound may be a monomer, an oligomer, or a mixture thereof.

[0169] The monofunctional (meth)acrylate compound is selected from the group consisting of monofunctional acrylate compounds and monofunctional methacrylate compounds. Examples of monofunctional (meth)acrylate compounds include phenoxyethyl acrylate (PEA), 2-Propenoic acid, 2-[2-(ethenyloxy)ethoxy]ethyl ester (VEEA), cyclic TMP formal acrylate (CTFA), isobornyl acrylate (IBOA), tetrahydrofurfuryl acrylate (THFA), 2-(2-ethoxy)ethyl acrylate, octadecyl acrylate (ODA), tridecyl acrylate (TDA), isodecyl acrylate (IDA), and lauryl acrylate. The preferred monofunctional (meth)acrylate compound is 2-Propenoic acid, 2-[2-(ethenyloxy)ethoxy]ethyl ester (VEEA).

[0170] Examples of polyfunctional (meth)acrylate compounds include compounds selected from the group consisting of polyfunctional acrylate compounds and polyfunctional methacrylate compounds, such as hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, polyethylene glycol diacrylate (e.g., tetraethylene glycol diacrylate), dipropylene glycol diacrylate, tri(propylene glycol) triacrylate, neopentyl glycol diacrylate, 3-methyl-1,5-pentanediol diacrylate, bis(pentaerythritol) hexaacrylate, and acrylate esters of ethoxylated or propoxylated glycols and polyols (e.g., propoxylated neopentyl glycol diacrylate, ethoxylated trimethylolpropane triacrylate, and mixtures thereof).

[0171] Furthermore, specific examples of polyfunctional (meth)acrylate compounds include hexanediol dimethacrylate, trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, and 1,4-butanediol dimethacrylate.

[0172] The polyfunctional (meth)acrylate compounds are preferably 3-methyl-1,5-pentanediol diacrylate and dipropylene glycol diacrylate.

[0173] The N-vinyl compound is preferably N-vinylpyrrolidone (NVP) or N-vinylcaprolactam (NVC), with N-vinylcaprolactam (NVC) being more preferred.

[0174] The total content of (meth)acrylate compounds and N-vinyl compounds in the ink is preferably 80% to 100% by mass, more preferably 90% to 100% by mass, and even more preferably 95% to 100% by mass, based on the total mass of polymerizable compounds in the ink.

[0175] The polymerizable compound content in the ink is preferably 50% to 95% by mass, more preferably 50% to 90% by mass, and even more preferably 60% to 90% by mass, based on the total solid content of the ink.

[0176] [Photopolymerization Initiator] The ink preferably contains a photopolymerization initiator. Examples of photopolymerization initiators include radical photopolymerization initiators. Examples of radical photopolymerization initiators include benzophenone, 1-hydroxycyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-benzyl-2-dimethylamino-(4-morpholinophenyl)butan-1-one, isopropylthioxanthone, benzyldimethylketal, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide.

[0177] Commercially available radical photopolymerization initiators include IRGACURE®, Darocur®, and LUCIRIN® (all manufactured by BASF).

[0178] The content of the photopolymerization initiator in the ink is preferably 1% by mass or more and 20% by mass or less, and more preferably 1% by mass or more and 15% by mass or less, relative to the total solid content of the ink.

[0179] [Effects of the First Embodiment] The printing system 10 according to the first embodiment can achieve the following effects.

[0180] [1] The supply channel 116, the recovery channel 118, the inter-tank channel 122, and the inter-sub-tank channel 142 are made of non-fluorine material such as non-fluorine resin in the parts that come into contact with the ink. This suppresses the charging of ink in the ink channels such as the supply channel 116, and prevents a decrease in the discharge state caused by the charging of ink.

[0181] [2] The tube 400 applied to the ink flow path such as the supply flow path 116 has a tube structure 402 that is covered with a first covering member 404, and the first covering member 404 is covered with a second covering member 406. The inner wall of the tube structure 402 that comes into contact with the ink is made of a non-fluorine material. This suppresses the charging of the ink flowing through the tube 400.

[0182] [3] The printing system 10 has a structure that circulates ink from the inkjet head 30 to the recovery tank 120. This allows charged ink present inside the inkjet head 30 to be discharged to the outside of the inkjet head 30.

[0183] [4] The supply head channel 172, the recovery head channel 176, and the circulation channel 182 provided in the inkjet head 30 are made of a non-fluorine material. This suppresses the charging of ink supplied to the head module 42 and the charging of ink discharged from the head module 42.

[0184] [5] A liquid-repellent layer 306 is formed on the discharge surface 42C where the nozzle opening 310 is formed. The liquid-repellent layer 306 is (L-Y-) k Si-(O-*) 4-kIt has a substructure represented as follows: L is a hydrocarbon group, Y is a single bond or a divalent linking group that does not contain a fluorine atom, k is an integer between 1 and 3, and * indicates the bond position with other structures. This suppresses the charging of the ink caused by contact between the liquid-repellent layer 306 and the ink.

[0185] [Example Configuration of Printing System According to the Second Embodiment] Figure 7 is a schematic diagram showing an example configuration of the printing system according to the second embodiment. The printing system 10A shown in the figure includes a static elimination support device that assists in eliminating static electricity from the inkjet head 30.

[0186] Figure 7 illustrates a humidifier 500 as an anti-static device, which humidifies the space where the inkjet head 30A is located. In the configuration equipped with the humidifier 500, when water-based ink is used, the drying of the ink can be suppressed.

[0187] Furthermore, the printing system 10A may be equipped with static elimination devices such as an ionizer and a static elimination blower as static elimination support devices. Figure 7 schematically illustrates the supply head channel static elimination device 502 and the recovery head channel static elimination device 504 built into the inkjet head 30A. The supply head channel static elimination device 502 performs static elimination on the supply head channel 172. The recovery head channel static elimination device 504 performs static elimination on the recovery head channel 176.

[0188] The humidifier 500 humidifies the space where the tube 400, which functions as a supply head flow path 172, is located, or blows static-eliminating air onto it. This suppresses the charging of the tube 400. It also suppresses the charging of the ink flowing through the tube 400.

[0189] The supply head channel static eliminator 502 and the recovery head channel static eliminator 504 may be located inside the cover 40 of the inkjet head 30, or they may be located outside the cover 40. If the supply head channel static eliminator 502 is located outside the cover 40, a blower such as a fan may be used to send humidified air or static elimination air into the cover 40.

[0190] The ink supply device 100A provided in the printing system 10A includes a supply channel static elimination device 510, a recovery channel static elimination device 512, an inter-tank channel static elimination device 514, and an inter-sub-tank channel static elimination device 516. The supply channel static elimination device 510 performs static elimination on the supply channel 116. The recovery channel static elimination device 512 performs static elimination on the recovery channel 118. The inter-tank channel static elimination device 514 performs static elimination on the inter-tank channel 122. The inter-sub-tank channel static elimination device 516 performs static elimination on the inter-sub-tank channel 142.

[0191] Although only one supply channel static elimination device 510 is shown in Figure 7, for example, multiple supply channel static elimination devices 510 may be provided depending on the arrangement path of the supply channel 116, and each of the multiple supply channel static elimination devices 510 may be arranged in a different position.

[0192] The supply channel static elimination device 510, recovery channel static elimination device 512, inter-tank channel static elimination device 514, and sub-tank channel static elimination device 516 shown in Figure 7 may be replaced with humidifiers.

[0193] The supply channel static elimination device 510 is an example of the first static elimination support device of this disclosure, the recovery channel static elimination device 512 is an example of the second static elimination support device of this disclosure, and the inter-tank channel static elimination device 514 is an example of the third static elimination support device of this disclosure.

[0194] [Effects of the Second Embodiment] The printing system 10A according to the second embodiment can obtain the following effects.

[0195] [1] The system is equipped with a humidifier 500 that humidifies the space where the inkjet head 30A is located. This suppresses static charge buildup in the space where the inkjet head 30A is located. In addition, when water-based ink is used, the drying of the ink is suppressed.

[0196] [2] The system is equipped with a supply head channel static elimination device 502, etc., which eliminates static electricity in the space where the tube 400, which functions as a supply head channel 172, etc., is located. This suppresses the charging of the tube 400. In addition, it suppresses the charging of the ink flowing through the tube 400.

[0197] [3] The system is equipped with a supply channel static elimination device 510, etc., which eliminates static electricity in the space where the tube 400, which functions as a supply channel 116, etc., is located. This suppresses the charging of the supply channel 116, etc. In addition, it suppresses the charging of the ink flowing through the tube 400.

[0198] The embodiments of the Disclosure described above can be modified, added to, or deleted as appropriate, without departing from the spirit of the Disclosure. The Disclosure is not limited to the embodiments described above, and many modifications are possible within the technical concept of the Disclosure by a person with ordinary skill in the art. Furthermore, the embodiments, modifications, and applications may be combined as appropriate.

[0199] 1 Medium 1A Printing surface 1B Support surface 10 Printing system 10A Printing system 12 Medium supply device 14 Pre-processing device 16 Printing device 18 Post-processing device 20 Inspection device 22 Printed material storage device 24 Transport device 30 Inkjet head 30A Inkjet head 30C Inkjet head 30K Inkjet head 30M Inkjet head 30W Inkjet head 30Y Inkjet head 32 Scanner 34 Pass roller 36 Tension pickup 40 Cover 42 Head module 42A Supply port 42B Recovery port 44 Head module support member 100 Ink supply device 100A Ink supply device 114 Supply tank 116 Supply channel 118 Recovery channel 120 Recovery tank 122 Inter-tank channel 124 Inter-tank pump 126 Inter-tank channel valve 130 Supply channel valve 132 Supply channel pump 134 Supply channel filter 136 Supply channel subtank 140 Recovery channel subtank 142 Inter-subtank channel 144 Inter-subtank channel valve 150 Liquid chamber 152 Flexible membrane 154 Gas chamber 156 Open to atmosphere chamber 160 Liquid chamber 162 Flexible membrane 164 Gas chamber 166 Open to atmosphere chamber 170 Supply manifold 172 Supply head channel 174 Supply head valve 176 Recovery head channel 178 Recovery head valve 180 Recovery manifold 182 Circulation channel 184 Circulation channel valve 200 Bracket 202 Clamp assembly 204 Ink supply unit 206 Tube 208 Flexible substrate 300 Ink ejection structure 302 Fluid path substrate 304 Nozzle substrate 306 Liquid-repellent layer 310 Nozzle opening 312 Downward channel 314 Fluid pump chamber 315 Individual supply channel 316 Common supply channel 318 Individual circulation channel 320 Common circulation channel 322 Internal protective film 330 Piezoelectric element 332 Diaphragm 400 Tube 402 Tube structure 404 First coating member 406 Second coating member 500 Humidifier 502 Supply head channel static eliminator 504 Recovery head channel static eliminator 510 Supply channel static eliminator 512 Recovery channel static eliminator 514 Inter-tank channel static eliminator 516 Inter-sub-tank channel static eliminator

Claims

1. A liquid discharge head comprising a fluid path substrate on which a fluid path is formed, wherein the fluid path comprises a fluid pump chamber, a pump chamber communication fluid path fluidly connected to the fluid pump chamber, and a nozzle fluidly connected to the pump chamber communication fluid path, the nozzle having a nozzle opening formed at its end for discharging liquid; and a liquid supply device for supplying liquid to the liquid discharge head, wherein the liquid supply device comprises a first tank for storing liquid, and a first flow path member connected to the first tank and the liquid discharge head, the first flow path member having a non-fluororesin material applied to the part that comes into contact with the liquid; and a liquid discharge system.

2. The liquid discharge system according to claim 1, wherein the material of the first flow channel member is at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

3. The liquid discharge system according to claim 1, wherein the first flow channel member includes a tube structure, and the material of the inner wall of the tube structure is at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

4. The liquid discharge system according to claim 1, further comprising a first static elimination support device for eliminating static electricity in at least one of the first flow channel member and the space in which the first flow channel member is arranged.

5. The liquid discharge system according to claim 4, wherein the first static elimination support device is at least one of a humidifier and a static elimination blower.

6. A liquid discharge system according to claim 1, comprising: a second tank for containing the liquid recovered from the liquid discharge head; and a second flow channel member connected to the second tank and the liquid discharge head, wherein the non-fluororesin is applied to the material of the portion that comes into contact with the liquid.

7. The liquid discharge system according to claim 6, wherein the material of the second flow channel member is at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

8. The liquid discharge system according to claim 6, wherein the second flow channel member includes a tube structure, and the material of the inner wall of the tube structure is at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

9. The liquid discharge system according to claim 6, further comprising a second static elimination support device for eliminating static electricity in at least one of the second flow channel member and the space in which the second flow channel member is arranged.

10. The liquid discharge system according to claim 9, wherein the second static elimination support device is at least one of a humidifier and a static elimination blower.

11. The liquid discharge system according to claim 6, comprising a third flow channel member connecting the first tank and the second tank, wherein the non-fluororesin is applied to the material of the portion of the third flow channel member that comes into contact with the liquid.

12. The liquid discharge system according to claim 11, wherein the material of the third flow channel member is at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

13. The liquid discharge system according to claim 11, wherein the third flow channel member includes a tube structure, and the material of the inner wall of the tube structure is at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

14. The liquid discharge system according to claim 11, further comprising a third static elimination support device for eliminating static electricity in at least one of the third flow channel member and the space in which the third flow channel member is arranged.

15. The liquid discharge system according to claim 14, wherein the third static elimination support device is at least one of a humidifier and a static elimination blower.

16. The liquid dispensing system according to claim 1, wherein the liquid is an ultraviolet-curable ink.

17. The liquid dispensing system according to claim 1, wherein the liquid dispensing head comprises a fourth flow channel member to which the non-fluororesin is applied as the material of the part that comes into contact with the liquid.

18. The liquid discharge system according to claim 17, wherein the material of the fourth flow channel member is at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

19. The liquid discharge system according to claim 17, wherein the fourth flow channel member includes a tube structure, and the material of the inner wall of the tube structure is at least one of polypropylene, polyethylene, polyamide, vinyl chloride, and polyimide.

20. The liquid dispensing system according to claim 1, wherein the non-fluororesin does not contain fluorine and includes a perfluoroalkyl structure or a polyfluoroalkyl structure as a partial structure.

21. The discharge surface on which the nozzle opening is formed has a liquid-repellent layer formed thereon, and the liquid-repellent layer is (L-Y-) k Si-(O-*) 4-k A liquid discharge system according to claim 1, having a substructure represented by , where L is a hydrocarbon group, Y is a single bond or a divalent linking group that does not contain a fluorine atom, k is an integer between 1 and 3, and * indicates a bond with another structure.

22. The liquid dispensing system according to claim 21, wherein the thickness of the liquid-repellent layer is 50 nanometers or less.

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