Printing unit and method for printing

Abstract

The present disclosure relates to a printing unit and a method for printing. The printing unit is used to spray a pre-treatment liquid or a post-treatment liquid. The printing unit includes one or more nozzles, each nozzle including: a vibration device array, which is used to vibrate based on a received target trigger signal, each vibration device in the vibration device array including a piezoelectric ceramic unit; a nozzle array, each nozzle in the nozzle array is driven by the vibration of a corresponding vibration device in the vibration device array to output a pre-treatment liquid or a post-treatment liquid from an ink cartridge; and an ink cartridge, which is connected to the nozzles in the nozzle array and is used to provide the pre-treatment liquid or the post-treatment liquid to the nozzles. The present disclosure can significantly improve the overall printing efficiency and printing quality, simplify the process and reduce the cost.

Description

Technical Field

[0001] The present disclosure relates generally to digital printing, and in particular, to printheads and methods for printing. Background Art

[0002] In the traditional printing scheme, the grey cloth to be printed is first sized using a dedicated sizing machine or a rotary screen process, and then the sized grey cloth is dried and rolled up, and then the printing equipment (such as digital printing equipment) is used to print the pattern on the dried grey cloth, and finally, the grey cloth with the pattern printed is dried and rolled up. It should be understood that before digital printing, by applying a pretreatment liquid (or slurry) on the grey cloth, the color and fineness of the digital printing pattern printed during digital printing can be better. However, in the above-mentioned traditional printing method, since the pretreatment liquid (or slurry) needs to be sized by a dedicated sizing machine or a rotary screen process, and additional drying equipment needs to be set up after sizing to dry the sized grey cloth, additional special equipment needs to be equipped, and the process is relatively complicated, the efficiency is not high, and the cost is high.

[0003] In summary, the shortcomings of traditional inkjet printing solutions are that they require additional dedicated sizing equipment for applying the pretreatment liquid, and drying equipment for drying the sizing grey cloth. As a result, the process is relatively complicated, the equipment cost is high, and the overall printing efficiency is low. Summary of the Invention

[0004] The present disclosure provides a printing unit and a printing method, which can significantly improve the overall printing efficiency and printing quality, simplify the process and reduce the cost.

[0005] According to a first aspect of the present disclosure, a printing unit is provided, which is used to spray a pre-treatment liquid or a post-treatment liquid, and is characterized in that the printing unit includes one or more nozzles, each nozzle including: a vibration device array, which is used to vibrate based on a received target trigger signal, each vibration device in the vibration device array includes a piezoelectric ceramic unit; a nozzle array, each nozzle in the nozzle array is driven by the vibration of the corresponding vibration device in the vibration device array to output the pre-treatment liquid or the post-treatment liquid from the ink cartridge; and an ink cartridge, which is connected to the nozzles in the nozzle array and is used to provide the pre-treatment liquid or the post-treatment liquid to the nozzles.

[0006] In some embodiments, each nozzle includes at least two parallel arrays of spray needles, and corresponding spray needles of the at least two parallel arrays of spray needles are staggered by a predetermined interval in the longitudinal direction of the spray needle array to improve the printing accuracy of the printing unit.

[0007] In some embodiments, the printing unit includes a plurality of nozzles, at least two of the plurality of nozzles are spliced horizontally or vertically, and the positioning pins of the at least two nozzles spliced horizontally are staggered by a predetermined distance in the longitudinal direction of the nozzle array, so that the corresponding nozzles included in the at least two nozzles spliced horizontally are staggered by a predetermined distance in the longitudinal direction of the nozzle array.

[0008] In some embodiments, each nozzle also includes: a nozzle cover plate, which is arranged on both sides of the ink cartridge to protect the nozzle needle array; an upper air knife, which is arranged on the upper part of the nozzle cover plate, and the air knife outlet of the upper air knife outputs air with a first predetermined air pressure along a first guide direction; and a lower air knife, which is arranged in an accommodating space jointly defined by the lower part of the ink cartridge and the lower part of the nozzle cover plate, and the air knife outlet of the lower air knife outputs or inhales air with a second predetermined air pressure along a second guide direction, and the first guide direction is different from the second guide direction.

[0009] In some embodiments, the first flow guiding direction is perpendicular to the spray needle, and the second flow guiding direction is parallel to the spray needle.

[0010] In some embodiments, the ink cartridge includes a treatment liquid inlet, a treatment liquid outlet, an air inlet interface and a spray needle interface, the air inlet interface is connected to the ink cartridge air supply system, and the ink cartridge air supply system includes: a safety bottle, one end of the safety bottle is connected to the air inlet interface of the ink cartridge, and the other end of the safety bottle is directly or indirectly connected to a negative pressure generator to prevent negative pressure from sucking pre-treatment liquid or post-treatment liquid into the negative pressure pipeline; a negative pressure generator is used to generate negative pressure to balance the ink cartridge and spray needle liquid levels to prevent the spray needle from dripping pre-treatment liquid or post-treatment liquid.

[0011] In some embodiments, the ink cartridge air supply system also includes: a positive and negative pressure conversion solenoid valve, one input end of the positive and negative pressure conversion solenoid valve is connected to the negative pressure generator, the other input end of the positive and negative pressure conversion solenoid valve is connected to the first pressure regulating valve, and the output end of the positive and negative pressure conversion solenoid valve is connected to the safety bottle; and a first gas source, respectively connected to the first pressure regulating valve and the second pressure regulating valve, the second pressure regulating valve is connected to the negative pressure generator, and the first pressure regulating valve is used to provide positive pressure when cleaning the printing unit.

[0012] In some embodiments, the treatment liquid inlet and the treatment liquid outlet are connected to the ink cartridge liquid supply system, and the ink cartridge liquid supply system includes: a liquid supply peristaltic pump, arranged between the liquid supply container and the filter; a liquid return peristaltic pump, arranged between the liquid supply container and the treatment liquid outlet of the ink cartridge; a filter, connected to the ink supply solenoid valve; and an ink supply solenoid valve, connected to the treatment liquid inlet of the ink cartridge.

[0013] In some embodiments, the printing unit further includes: a moisturizing device for preventing the spray needle from being blocked when the printing unit is not in use, and the moisturizing device includes an elastomer.

[0014] According to a second aspect of the present disclosure, a method for printing is provided. The method comprises: upon detecting that an object to be printed has reached a first printing position, outputting a first target trigger signal to a first vibrating device array of a pre-treatment liquid printing unit, so that based on the vibration of the first vibrating device array, the first needle array of the pre-treatment liquid printing unit is driven by the first vibrating device array to spray the pre-treatment liquid onto a predetermined area of the object to be printed, wherein the pre-treatment liquid printing unit is the printing unit according to the first aspect; and upon detecting that the object to be printed has reached a second printing position, driving a print printing unit to output printing liquid onto the object to be printed sprayed with the pre-treatment liquid, so as to generate a target print pattern on the object to be printed.

[0015] In some embodiments, driving the print printing unit to output printing liquid to the object to be printed that has been sprayed with a pre-treatment liquid includes: outputting a second target trigger signal to the second vibration device array of the print printing unit, so as to drive the second needle array of the print printing unit based on the vibration of the second vibration device array to output printing liquid to the object to be printed that has been sprayed with a pre-treatment liquid under the drive of the second vibration device array, and the print printing unit and the pre-treatment liquid printing unit are arranged on the beam included in the printing device.

[0016] In some embodiments, the method for printing also includes: if it is detected that the object to be printed with the target printing pattern reaches the third printing position, outputting a third target trigger signal to the third vibration device array of the post-processing liquid printing unit, so as to drive the third needle array of the post-processing liquid printing unit based on the vibration of the third vibration device array. Under the drive of the third vibration device array, the post-processing liquid is sprayed onto the object to be printed with the target printing pattern. The post-processing liquid printing unit is a printing unit according to the first aspect.

[0017] In some embodiments, at least one of the pre-treatment liquid printing unit and the post-treatment liquid printing unit is formed by horizontal and / or vertical splicing of multiple nozzles, and the method further includes at least one of the following: based on the number and accuracy of the nozzles of the pre-treatment liquid printing unit, determining the amount of auxiliary agents used for spraying simultaneously with the pre-treatment liquid, the auxiliary agents including at least one of darkening and brightening agents, color fastness enhancers, whitening agents, pH value regulators, cationic modifiers, penetrants, dispersants, surfactants, inorganic salts, anti-migration agents, hydrophilic agents, moisturizers, and urea substitutes; and driving the nozzle frame for supporting the pre-treatment liquid printing unit and the print printing unit to drive the pre-treatment liquid printing unit and the print printing unit to scan back and forth.

[0018] In some embodiments, the pretreatment liquid includes at least one of a water-soluble liquid, a water-soluble slurry, a non-water-soluble emulsion, an organic solvent, and an oily medium.

[0019] In some embodiments, the predetermined area of the object to be printed on which the pre-treatment liquid is sprayed is a target area on which a graphic in the target pattern is to be sprayed.

[0020] In some embodiments, the method for printing further includes: in response to determining that the pre-treatment liquid printing unit and the print printing unit are scanning back and forth, turning on the suction device to control the printing liquid floating on the object to be printed within the printing area.

[0021] In some embodiments, the method for printing further includes: controlling a drying device to dry the object to be printed on which the target printing pattern is generated.

[0022] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the disclosure, nor is it intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a system for implementing a printing method according to the prior art is shown.

[0024] Figure 2 A schematic diagram of a system for implementing a printing method according to some embodiments of the present disclosure is shown.

[0025] Figure 3A A schematic top view of a partial structure of a printing unit for spraying a pre-treatment liquid or a post-treatment liquid according to some embodiments of the present invention is shown.

[0026] Figure 3B A schematic side view of a partial structure of a printing unit for spraying a pre-treatment liquid or a post-treatment liquid according to some embodiments of the present invention is shown.

[0027] Figure 3C A schematic top view of a printing unit for spraying a pre-treatment liquid or a post-treatment liquid according to some embodiments of the present invention is shown.

[0028] Figure 4A A partial cross-sectional schematic diagram of an air knife in an installed state according to an embodiment of the present invention is shown.

[0029] Figure 4B A side view of a needle fixing board in an installed state is shown according to an embodiment of the present invention.

[0030] Figure 4C A front view of a needle fixing board in an uninstalled state according to an embodiment of the present invention is shown.

[0031] Figure 4DA front view of a control unit in an installed state is shown according to an embodiment of the present invention.

[0032] Figure 5 A schematic diagram of an ink cartridge air supply system according to an embodiment of the present invention is shown.

[0033] Figure 6 A schematic diagram of an ink cartridge liquid supply system according to an embodiment of the present invention is shown.

[0034] Figure 7 A schematic diagram of a power supply and control system according to an embodiment of the present invention is shown.

[0035] Figure 8 A flow chart of a method for printing according to some embodiments of the present invention is shown.

[0036] Figure 9 A flow chart illustrating a method for determining the amount of an auxiliary agent for simultaneous spraying with a pre-treatment liquid according to some embodiments of the present invention is shown.

[0037] In the various drawings, the same or corresponding reference numerals denote the same or corresponding parts. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0039] As used herein, the term "including" and its variations represent open inclusion, i.e., "including but not limited to." Unless otherwise stated, the term "or" means "and / or." The term "based on" means "based at least in part on." The terms "one example embodiment" and "an embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one additional embodiment." The terms "first," "second," etc. may refer to different or identical objects.

[0040] Figure 1 Schematic diagram of a system for implementing a printing method in the prior art is shown. Figure 1As shown, the system 100 includes: a grey fabric 102, a sizing machine 104, a first drying device 106, a winding device 108, a digital printing machine 110 (the digital printing machine 110 is equipped with a printing unit 112 for digital printing), and a second drying device 114. As mentioned above, in the traditional printing solution, it is first necessary to use a dedicated sizing machine 104 to sizing the grey fabric 102 to be digitally printed, then use the first drying device 106 to dry the sizing grey fabric, and use the winding device 108 to wind the dried grey fabric; then, use the printing unit 112 equipped with the digital printing machine 110 to print a pattern on the grey fabric, and the printed grey fabric is then dried in the second drying device 114. In summary, the shortcomings of the above-mentioned traditional system for implementing the printing method are: it is necessary to be equipped with a special sizing equipment (for example, the sizing machine 104) for applying an additional pre-treatment liquid, and it is necessary to be equipped with additional drying equipment (for example, the first drying device 106) to dry the grey cloth after sizing. Therefore, the process is more complicated, the equipment cost is high, and the overall printing efficiency is not high.

[0041] To at least partially address one or more of the above-mentioned problems and other potential problems, exemplary embodiments of the present disclosure provide a printing unit for spraying a pre-treatment liquid or a post-treatment liquid. The printing unit includes one or more nozzles, each nozzle including: an array of vibrating devices configured to vibrate based on a received target trigger signal, wherein the vibration of a corresponding vibrating device in the vibrating device array drives a corresponding nozzle in a nozzle array to resonate, thereby outputting the pre-treatment liquid or post-treatment liquid from an ink cartridge; and an ink cartridge connected to the nozzles in the nozzle array for supplying the pre-treatment liquid or post-treatment liquid to the nozzles. The present invention eliminates the need for additional dedicated sizing machines and drying equipment, and allows the spraying of the pre-treatment liquid to proceed synchronously with the digital printing process, thereby simplifying conventional sizing machine or rotary screen sizing and winding processes and shortening the process flow. Furthermore, no dedicated sizing machine or intermediate drying equipment is required between the pre-treatment liquid and the printing process, enabling wet-on-wet printing. This not only improves the uniformity, permeability, and bonding of the dye on the printed object, thereby improving the quality of the digital printing, but also significantly saves dye. Therefore, the present invention can significantly improve the overall printing efficiency and printing quality, and simplify the process and reduce the cost.

[0042] Figure 2 Schematic diagram of a system 200 for implementing a printing method according to some embodiments of the present disclosure is shown. Figure 2As shown, the system 200 includes, for example, an object to be printed 202, a pre-treatment liquid printing unit 204, a print printing unit 206, and a control device 212. In some embodiments, the system 200 may further include, for example, a drying device 210, a post-treatment liquid printing unit 216, and a beam 214. Figure 2 As shown, the pre-treatment liquid printing unit 204 and the print printing unit 206 are arranged on the crossbeam 214 of the printing device 208. In addition, the control device 212 can exchange data with the pre-treatment liquid printing unit 204, the print printing unit 206, the drying device 210, and the post-treatment liquid printing unit 216.

[0043] Regarding the pre-treatment liquid printing unit 204, it is used to spray the pre-treatment liquid onto a predetermined area of the object to be printed. The pre-treatment liquid printing unit 204 is configured upstream of the print printing unit 206 (i.e., configured before the print printing unit 206). In some embodiments, the pre-treatment liquid printing unit 204 and the print printing unit 206 are configured on a beam 214 configured by the printing device 208. It should be understood that by using the pre-treatment liquid printing unit 204 configured at the front end of the print printing unit to spray the pre-treatment liquid to replace the sizing process of traditional digital printing, the traditional dedicated sizing equipment can be eliminated, saving waste of slurry. In addition, by synchronously spraying the pre-treatment liquid and printing the target pattern, it is beneficial to improve the printing efficiency, reduce equipment costs, and simplify the process.

[0044] The pre-treatment liquid printing unit 204 includes, for example, one or more nozzles. In some embodiments, the pre-treatment liquid printing unit 204 is formed by a plurality of nozzles being spliced horizontally or vertically. For example, the pre-treatment liquid printing unit 204 may be a nozzle configured with 42 nozzles, which may be a printing unit formed by splicing nozzles of one or more single-row nozzle arrays. The specific structure of the printing unit composed of nozzles spliced horizontally will be described below in conjunction with Figure 3 and will not be repeated here. Each nozzle included in the printing unit includes at least a vibration device array, a nozzle array and an ink cartridge. The vibration device array includes a plurality of vibration devices, each vibration device includes a piezoelectric ceramic unit, and the vibration device array is used to vibrate based on the received target trigger signal. The nozzle array includes a plurality of nozzles, each nozzle is driven by the vibration of the corresponding vibration device in the vibration device array to output the pre-treatment liquid or post-treatment liquid from the ink cartridge. The ink cartridge is connected to the nozzles in the nozzle array for providing the pre-treatment liquid or post-treatment liquid to the nozzles.

[0045] Regarding the pre-treatment liquid, it includes, for example, at least one of a water-soluble liquid, a water-soluble slurry, a water-soluble emulsion, an organic solvent, and an oily medium. The pre-treatment liquid can also be at least one of a cationic auxiliary agent, an adhesive, an inorganic salt solution, a synthetic paste, a natural paste, and various compounded emulsions. The post-treatment liquid can be at least one of a waterproof coating, a darkening agent, a whitening agent, a color fixative, a softener, and an antistatic agent. In some embodiments, the post-treatment liquid can also be a special finishing agent, such as a fragrance, an antibacterial agent, and an auxiliary agent for any of the functions of antiviral, anti-ultraviolet, probiotic, mosquito repellent, ice feeling, and skin care. It should be understood that by spraying the pre-treatment liquid first and then spraying the ink for printing, wet-on-wet printing can be achieved, which can increase the uniformity, color yield, fineness, and permeability of the dye or coating on the object to be printed (for example, but not limited to fabric), thereby improving the quality of digital printing and increasing the added value of digital printing products.

[0046] It should be understood that in some embodiments, the printing device 208 may be equipped with multiple pre-treatment liquid printing units (e.g., including a first pre-treatment liquid printing unit and a second pre-treatment liquid printing unit) as needed. The first pre-treatment liquid printing unit is, for example, disposed upstream of the second pre-treatment liquid printing unit and is configured to spray other additives that are beneficial to improving printing quality, such as color darkening and brightening agents, color fastness enhancers, pH regulators, whitening agents, cationic modifiers, and other related additives, in addition to spraying the traditional pre-treatment liquid.

[0047] Regarding the crossbeam 214, it is used to support the pre-treatment liquid printing unit 204 and the print printing unit 206. In some embodiments, the crossbeam 214 can be raised or lowered as needed (for example, but not limited to, based on the output instructions of the control device 212), and the height adjustment range of the crossbeam 214 is, for example, 1-100 mm. In some embodiments, a nozzle rack ( Figure 2 (Not shown in the figure, in some embodiments, the print printing unit 206 is composed of, for example, an inkjet nozzle rather than a needle nozzle). The nozzle holder is used to adjust the nozzle angle of the pre-treatment liquid printing unit 204 and / or the print printing unit 206. In some embodiments, the nozzle holder can adjust the nozzle angle in a range of, for example, -90° to 90°. When the nozzle angle is -90°, the nozzle is vertically pointing upward; when the nozzle angle is 90°, the nozzle is vertically pointing downward.

[0048] The print unit 206 is used to deliver printing liquid to the object to be printed, which has been sprayed with a pre-treatment liquid, to produce a target print pattern on the object. In some embodiments, the print unit 206 includes at least a vibrator array, a needle array, and an ink cartridge. It should be understood that the print unit 206 may also be another type of digital print unit.

[0049] The drying device 210 is disposed downstream of the print unit 206. In some embodiments, the distance between the drying device 210 and the print unit 206 is greater than or equal to 50 cm. The drying device 210 is used to dry the object to be printed with the target print pattern.

[0050] The control device 212 is configured to control printing. Specifically, if the control device 212 detects that the object to be printed has reached a first printing position, the control device 212 outputs a first target trigger signal to the first vibrator array of the pre-treatment liquid printing unit, so that based on the vibration of the first vibrator array, the needle array of the pre-treatment liquid printing unit is driven by the first vibrator array to spray the pre-treatment liquid onto a predetermined area of the object to be printed. Furthermore, if the control device 212 detects that the object to be printed has reached a second printing position, the control device 212 drives the printing unit to output printing liquid onto the object to be printed that has been sprayed with the pre-treatment liquid, so as to generate a target printing pattern on the object to be printed. In some embodiments, the control device 212 is further configured to output a third target trigger signal to the third vibrator array of the post-treatment liquid printing unit, so that based on the vibration of the third vibrator array, the third needle array of the post-treatment liquid printing unit is driven by the third vibrator array to spray the post-treatment liquid onto the object to be printed that has been sprayed with the target printing pattern. The control device 212 can be implemented, for example, using an MCU (Micro Controller Unit), a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an FPGA (Field Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit).

[0051] The post-treatment liquid printing unit 216 is used to spray the post-treatment liquid onto the target pattern of the object to be printed. The post-treatment liquid printing unit 216 is positioned downstream of the drying device 210. In some embodiments, the distance between the post-treatment liquid printing unit 216 and the drying device 210 is greater than or equal to 10 cm. In some embodiments, the post-treatment liquid printing unit 216 also includes at least a vibrator array, a needle array, and an ink cartridge. The ink cartridge of the post-treatment liquid printing unit 216 is connected to the needles in the needle array to supply the post-treatment liquid to the needles.

[0052] The following combination Figure 3A 、 3B and Figure 3C Describes the structural details of a printing unit composed of two laterally spliced nozzles for spraying pre-treatment liquid or post-treatment liquid. Figure 3A A schematic top view of a partial structure of a printing unit 300 for spraying a pre-treatment liquid or a post-treatment liquid according to some embodiments of the present invention is shown. Figure 3B A schematic side view of a partial structure of a printing unit for spraying a pre-treatment liquid or a post-treatment liquid according to some embodiments of the present invention is shown. Figure 3C A schematic top view of a printing unit for spraying a pre-treatment liquid or a post-treatment liquid according to some embodiments of the present invention is shown.

[0053] like Figure 3A As shown, the printing unit 300 includes at least a plurality of nozzles. For example, a first nozzle 302 and a second nozzle 304. In some embodiments, the printing unit 300 further includes, for example: a moisturizing device, an air suction device and a cover body. The moisturizing device is used to prevent the nozzle needle from being blocked when the printing unit is not in use. In some embodiments, the moisturizing device includes a moisturizing box and / or a moisturizing elastomer 350 (for example, but not limited to a moisturizing sponge), which is used to moisturize the needle tip of the nozzle needle that is not in use to prevent the nozzle needle from being blocked. The moisturizing box is used to contain liquid for moisturizing the nozzle needle. When the printing unit finishes working, the control device 212 outputs an instruction to control the nozzle frame to drive the printing unit of the pre-treatment liquid or the post-treatment liquid to move to the moisturizing position, and lowers the height of the printing unit so that the needle tip of the nozzle is soaked by the moisturizing elastomer adsorbed with liquid, thereby moisturizing the needle tip of the nozzle needle that is not in use. Regarding the air suction device and the cover body, as Figure 3C As shown, a cover 352 is disposed outside of multiple nozzles (e.g., the first nozzle 302 and the second nozzle 304) to cover the nozzles and the printing area 356. The cover 352 is provided with one or more suction devices 354. When the control device 212 determines that the pre-treatment liquid printing unit and the flower print unit are performing back-and-forth scanning motions, the suction devices are activated to control the printing liquid floating on the object to be printed within the printing area 356.

[0054] Regarding the nozzle, it includes, for example: a vibration device array ( Figure 3A Not shown), needle array, ink cartridge 320 ( Figure 3A The vibrating device array includes a plurality of vibrating devices configured to vibrate based on a target trigger signal from a control device, each vibrating device including a piezoelectric ceramic unit. Each piezoelectric ceramic unit is disposed on each metal plate. Each metal plate includes a through hole (e.g., a through hole) for mounting the piezoelectric ceramic unit. Figure 4A The metal plate includes a coating material (indicated by reference numeral 442), a coating material disposed on the surface of the piezoelectric ceramic unit, and nozzles disposed on the edge of the metal plate. A through-hole is located in the center of the metal plate for mounting the nozzle array. The piezoelectric ceramic unit, for example, is disposed on one side of the metal plate and is configured to vibrate the metal plate under the control of a trigger signal having a trigger frequency, thereby driving the corresponding nozzles on the edge of the metal plate to resonate, thereby causing the pre-treatment liquid or post-treatment liquid to be ejected from the corresponding nozzles.

[0055] In some embodiments, each nozzle further includes, for example, a positioning pin (e.g., mark 306 indicates the positioning pin of the first nozzle 302, and mark 308 indicates the positioning pin of the second nozzle 304), and a nozzle array fixing device (e.g., mark 316 indicates the fixing screw of the first nozzle 302, and mark 318 indicates the fixing screw of the second nozzle 304). The positioning pins are located on both sides of the nozzle array and are used to couple with the positioning holes on both sides of the ink cartridge to fix the nozzle. The nozzle array fixing device is used to couple with the nozzle array fixing units (e.g., screw holes) on both sides of the ink cartridge to fix the nozzle array to the ink cartridge.

[0056] Regarding the plurality of nozzles, in some embodiments, they may be spliced in parallel (or transversely, i.e., the nozzle arrays of the parallel-spliced nozzles are longitudinally parallel to each other). In some embodiments, at least some of the plurality of nozzles may be spliced longitudinally (i.e., the nozzle arrays of the longitudinally spliced nozzles are longitudinally collinear). In some embodiments, the plurality of nozzles may be spliced partially longitudinally and partially parallel.

[0057] Regarding the parallel splicing method of nozzles, such as Figure 3A As shown, the first nozzle 302 and the second nozzle 304 are arranged in parallel along the longitudinal direction of the nozzle array, thereby improving the printing efficiency of the nozzle 300. Specifically, the corresponding nozzles of the two adjacent parallel spliced (or parallel arranged) nozzles are arranged in the longitudinal direction of the nozzle array (for example Figure 3A The predetermined physical spacing (for example, the first predetermined physical spacing) is staggered in the direction indicated by the X-axis in the middle) to improve the precision of the liquid spraying superposition of the nozzle. Figure 3AAs shown, by offsetting the position of the locating pin 308 of the second nozzle 304 by 1.270 mm relative to the position of the locating pin 306 of the first nozzle 302 along the X-axis, each nozzle of the third nozzle array 322 of the second nozzle 304 is offset by 1.270 mm relative to each corresponding nozzle of the first nozzle array 312 of the first nozzle 302 along the X-axis. For example, if each nozzle of the printing unit 300 includes a single row of nozzle arrays, the needle pitch of the single row of nozzle arrays is 2.54 mm, and the accuracy of each nozzle is 10 dpi. If two nozzles are spliced in parallel and the corresponding nozzles are staggered, the accuracy of the nozzles is improved to 20 dpi. If three nozzles are spliced in parallel and the nozzles are staggered, the accuracy of the printing unit is improved to 30 dpi.

[0058] As mentioned above, each printhead includes a needle array. In some embodiments, each printhead includes one, two, or even more rows of needle arrays and a vibration device array arranged parallel to the longitudinal direction of the needle array. Each needle array includes multiple needles, each driven by the vibration of a corresponding vibration device in the vibration device array included in the same printhead to output pre-treatment liquid or post-treatment liquid from the ink cartridge. In some embodiments, the corresponding needles in the multiple rows of needle arrays included in each printhead are staggered by a predetermined physical spacing along the longitudinal direction of the needle array to improve the accuracy of the superimposed sprays of the printing unit. This can further improve the accuracy of the printhead and the uniformity of the sprayed pre-treatment liquid or post-treatment liquid.

[0059] like Figure 3A As shown, the first nozzle 302 includes two rows of parallel nozzle arrays, for example, a first nozzle array 312 and a second nozzle array 314. Furthermore, each nozzle of the second nozzle array 314 included in the first nozzle array 302 is staggered (for example, offset in the X-axis direction) relative to each corresponding nozzle of the first nozzle array 312 by a predetermined physical spacing (for example, a second predetermined physical spacing, for example but not limited to 0.635 mm, the second predetermined physical spacing may be equal to or different from the first predetermined physical spacing). For example, by mounting the second nozzle array 314 to the limiting portion (for example, the positioning hole, Figure 3A The position of the limiting portion of the nozzle array mounting structure on the first side of the ink cartridge 320 relative to the first nozzle array 312 is offset by 0.635 mm, so that the first nozzle of the second nozzle array 314 is staggered by 0.635 mm along the X-axis direction relative to the first corresponding nozzle of the first nozzle array 312.

[0060] In some embodiments, as Figure 3AAs shown, the position of the locating pin 308 of the second nozzle 304 is offset by 1.270 mm along the X-axis relative to the position of the locating pin 306 of the first nozzle 302. Furthermore, the position limiter of the nozzle array mounting structure of the fourth nozzle array 324 mounted on the second side of the ink cartridge 320 is offset by 0.635 mm relative to the position limiter of the nozzle array mounting structure of the third nozzle array 322 mounted on the first side of the ink cartridge 320. Therefore, each nozzle of the third nozzle array 322 is offset by 0.635 mm relative to each corresponding nozzle of the second nozzle array 314 along the X-axis, and each nozzle of the fourth nozzle array 324 is offset by 0.635 mm relative to each corresponding nozzle of the third nozzle array 312 along the X-axis. By offsetting the corresponding nozzles of different nozzle arrays in the same nozzle head, the present disclosure can further improve the spraying accuracy of the printing unit, thereby further improving the uniformity of the treatment liquid spraying. For example, the single-row pitch of each needle array of the printing unit 300 is, for example, but not limited to, 2.54 mm, with an accuracy of 10 dpi. By paralleling the nozzles, staggering the needle arrays of different nozzles using positioning pins, and staggering the needles of different needle arrays of the same nozzle using the stopper of the nozzle array mounting structure, the accuracy of the printing unit 300 is improved to 40 dpi.

[0061] The ink cartridge 320 is connected to the multiple needles of the needle array included in the same nozzle head, and is used to provide pre-treatment liquid or post-treatment liquid to the multiple needles. The ink cartridge 320 includes: an ink cartridge chamber, an ink cartridge cover (in Figure 3A and 3B The ink cartridge cover is omitted to expose the internal structure of the ink cartridge), the liquid level gauge 332, the nozzle air inlet interface (for example, Figure 3A The mark 336 in the middle indicates the nozzle air inlet interface of the first nozzle 302), the treatment liquid inlet, and the treatment liquid outlet. The liquid level meter 332 includes a position-adjustable liquid level balance tube that is inserted into the ink cartridge and located above the pre-treatment liquid or the post-treatment liquid. The liquid level balance tube is used to suck away the pre-treatment liquid or the post-treatment liquid above the lowest end of the liquid level balance tube to maintain a predetermined liquid level. The nozzle air inlet interface is used to apply negative pressure on the liquid level to prevent the liquid in the spray needle from dripping due to gravity. The treatment liquid inlet is connected to the peristaltic pump outside the nozzle to provide pre-treatment liquid or post-treatment liquid to the ink cartridge cavity. Regarding the ink cartridge liquid supply system of the ink cartridge 320, the following will be combined Figure 6 The detailed description will not be repeated here.

[0062] In some embodiments, each nozzle further includes: a nozzle cover plate, an upper air knife, a lower air knife, and a nozzle fixing plate. Figure 4A Specifically describe the specific structure of the nozzle cover plate, upper air knife and lower air knife. Figure 4AA partial cross-sectional schematic diagram of an air knife in an installed state according to an embodiment of the present invention is shown.

[0063] like Figure 4A As shown, the nozzle further includes: a nozzle cover plate 418, an upper air knife 410 and a lower air knife 420, and a nozzle fixing plate.

[0064] Regarding the nozzle cover plate 418, it is provided on both sides of the ink cartridge to protect the nozzle array. In some embodiments, the nozzle cover plate 418 is provided with a nozzle protection structure 432 near the end of the nozzle 430. The nozzle protection structure 432 prevents the needle tip of the nozzle 430 from being exposed, thereby protecting the nozzle 430.

[0065] The upper air knife 410 is disposed on the upper portion of the nozzle cover 418 and on the upper portion of the outer side wall of the ink cartridge. In some embodiments, the upper air knife 410 includes an upper air knife outlet 414, an upper air knife back air inlet 416, and an upper air knife end air outlet 412. The upper air knife outlet 414 outputs air at a first predetermined air pressure along a first flow direction. In some embodiments, the nozzle cover 418 serves as an upper air outlet air guide surface. The upper air knife outlet 414 is, for example, a narrow slit (for example, but not limited to, 0.05 mm). Compressed air enters the upper air knife 410 through the upper air knife back air inlet 416 and is blown out through the upper air knife outlet 414, forming a thin air curtain with a first predetermined air pressure. Guided by the nozzle cover 418, the pre-treatment liquid or post-treatment liquid ejected from the spray needle 430 is directed vertically downward and evenly distributed. In some embodiments, the wind force and wind speed ejected by the upper air knife 410 can be adjusted. By adjusting the wind force and wind speed of the upper air knife 410 , it can be ensured that the sprayed pre-treatment liquid or post-treatment liquid is evenly distributed on the object to be printed.

[0066] The lower air knife 420 is disposed in a receiving space 422 defined by the lower portion of the ink cartridge and the lower portion of the nozzle cover plate, and is disposed behind the nozzle needle 430. Figure 4AAs shown, the design of the above-mentioned accommodating cavity 422 can cleverly accommodate the lower air knife 420 in the accommodating cavity 422 at the bottom of the ink cartridge. When the nozzle is operating at a relatively low printing height of 3-5 mm from the object to be printed, the air outlet or air suction effect of the lower air knife 420 at the nozzle needle 430 will not cause ink hanging on the bottom or ink floating, and is conducive to improving the spraying uniformity of the nozzle. In some embodiments, the lower air knife 420 includes: a lower air knife air outlet 424, a lower air knife air inlet, an upper air knife air outlet, and a lower air outlet air guide surface 428. The lower air knife air outlet 424 outputs wind with a second predetermined air pressure along a second guide direction, and the first guide direction is different from the second guide direction. For example, the first guide direction is perpendicular to the nozzle needle, and the second guide direction is parallel to the nozzle needle. In some embodiments, down air knives 420 are installed on both sides of the nozzle at the same time, and the down air knife 420 is configured as a suction air knife. The function of the down air knife 420 is to absorb the pre-treatment liquid or post-treatment liquid that floats out of the nozzle, ensuring that the boundary of the printing area is clear, while preventing pollution of the equipment and the external environment.

[0067] Regarding the needle fixing board, it is used to fix the vibration device array and the needle array, as well as to cool the vibration device array, the needle array and the control unit. Figure 4B 、 4C Figure 4D and Figure 4D illustrate the structural details of the needle fixing plate. Figure 4B A side view of a needle fixing board in an installed state is shown according to an embodiment of the present invention. Figure 4C A front view of the needle retaining plate 440 in an uninstalled state is shown according to an embodiment of the present invention. Figure 4D A front view of a control unit 444 is shown in an installed state according to an embodiment of the present invention.

[0068] like Figure 4A As shown, the nozzle fixing plate 440 is installed between the outer wall of the ink cartridge and the nozzle cover plate. The nozzle fixing plate includes: a nozzle fixing groove array 450, a plate limiting step 448, a coolant channel 446, and a heat transfer surface 442. The nozzle fixing groove array 450 includes a plurality of nozzle fixing grooves, each of which is used to respectively fix a corresponding nozzle in the nozzle array and a vibration device (i.e., a metal plate and a piezoelectric ceramic unit thereon). The plate limiting step 448 is provided between the heat transfer surface and the nozzle fixing groove array and is used to position the control unit 444, which is included in the control device. The coolant channel 446 is used for the flow of coolant. The transfer surface 442 is provided on the surface of the coolant channel and is in surface contact with the control unit 444. It is used to transfer heat from the control unit 444, the corresponding nozzle 430, and the piezoelectric ceramic unit to the coolant flowing through the coolant channel 446.

[0069] like Figure 4BAs shown, when the needle retaining plate 440 is installed on the outer wall of the ink cartridge 320, the lower edge of the plate-shaped control unit 444 is supported by the plate retaining step 448; one side of the control unit 444 contacts the heat transfer surface 442. It should be understood that during operation of the printing unit, the operating circuit of the control unit generates a large amount of heat energy, and each needle in the needle array also generates heat energy. The heat energy generated by the needles is transferred to the needle retaining slot array 450; the heat energy generated by the control unit 444 is transferred to the plate retaining step 448 and the heat transfer surface 442, and then to the coolant channel 446. The needle retaining plate 440 is a copper structure designed to integrate the needle retaining structure and cooling system. It has excellent thermal conductivity, thus transferring heat to the coolant, which is then discharged to the outside through the coolant, thereby maintaining a suitable internal temperature of the nozzle and ensuring the proper operation of the printing unit.

[0070] It should be noted that the nozzle fixing slot array 450 is insulated from each nozzle array, each corresponding piezoelectric ceramic unit, the flexible electrode, the nozzle 430, and the through hole 442. As a result, each trigger signal can be independently applied to the piezoelectric ceramic unit corresponding to each nozzle, thereby independently controlling the vibration of the piezoelectric ceramic unit and, in turn, independently driving each nozzle.

[0071] The following will be combined Figure 5 The ink cartridge air path control system 500 is described in detail. Figure 5 A schematic diagram of an ink cartridge air supply system 500 according to an embodiment of the present invention is shown. The ink cartridge air supply system 500 includes: a first air source 502, a first pressure regulating valve 504, a second pressure regulating valve 506, a negative pressure generator 510, a positive and negative pressure switching solenoid valve 508, an air inlet port 512, a safety bottle 514, and a pressure gauge 516.

[0072] Regarding the first gas source 502, its pressure is, for example, greater than or equal to 100 kPa. The first gas source 502 is connected to the input of a first pressure regulating valve 504 and the input of a second pressure regulating valve 506. One path of gas outputted from the first gas source 502 is connected to one input of a positive-negative pressure switching solenoid valve 508 via the first pressure regulating valve 504. The other path of gas outputted from the first gas source 502 is connected to the other input of the positive-negative pressure switching solenoid valve 508 via the second pressure regulating valve 506 and a negative pressure generator 510.

[0073] The first pressure regulating valve 504 is used to regulate the pressure of the gas from the first gas source 502 to positive pressure gas. The output end of the first pressure regulating valve 504 is connected to an input end of the positive and negative pressure switching solenoid valve 508 .

[0074] Regarding the second pressure regulating valve 506 , an output end thereof is connected to an input end of the negative pressure generator 510 , and is used to regulate the pressure of the gas from the first gas source 502 into a negative pressure gas having a predetermined pressure value.

[0075] Regarding the negative pressure generator 510 , its output end is connected to the other input end of the positive and negative pressure switching solenoid valve 508 .

[0076] The positive / negative pressure switching solenoid valve 508 is, for example, a three-way positive / negative pressure switching solenoid valve. One input of the positive / negative pressure switching solenoid valve 508 is connected to its output, and the other input is connected to the output of the first pressure regulating valve 504. The output of the positive / negative pressure switching solenoid valve 508 is connected to the safety bottle 514.

[0077] Regarding the safety bottle 514, one end of the safety bottle is connected to the air inlet interface 512 of the ink cartridge, and the other end of the safety bottle 514 is directly or indirectly connected to the negative pressure generator 510, which is used to prevent the pre-treatment liquid or post-treatment liquid in the ink cartridge from being sucked into the pipeline of the ink cartridge air control system.

[0078] In some embodiments, each nozzle is configured with a separate air supply system. This is because the predetermined pressure value of each nozzle is different. This is because there are differences in the pipelines and ink channels of each nozzle. By configuring a separate air supply system for each nozzle, more accurate and independent control of the processing liquid of the nozzle needle can be achieved.

[0079] The following will be combined Figure 6 The ink cartridge liquid supply system 600 is described in detail. Figure 6 FIG. 6 is a schematic diagram showing an ink cartridge liquid supply system 600 according to an embodiment of the present invention. Figure 6 As shown, the ink cartridge liquid supply system 600 includes: a liquid supply container 602, a liquid supply peristaltic pump 604, a liquid return peristaltic pump 606, a filter 610, and a liquid supply solenoid valve 612. The liquid supply peristaltic pump 604 is arranged between the liquid supply container 602 and the filter 610. The filter 610 is connected to the liquid supply solenoid valve 612. The liquid supply solenoid valve 612 is connected to the process liquid inlet 614 of the ink cartridge. The liquid return peristaltic pump 606 is arranged between the liquid supply container 602 and the process liquid outlet 608 of the ink cartridge. During the operation of the printing unit, the pre-treatment liquid or post-treatment liquid provided by the liquid supply peristaltic pump 604 enters the ink cartridge through the treatment liquid inlet 614. When the liquid level of the current treatment liquid or post-treatment liquid exceeds the liquid level gauge, the pre-treatment liquid or post-treatment liquid above the liquid level gauge will be pumped away by the liquid return peristaltic pump 606 through the treatment liquid outlet 608 of the ink cartridge. Thus, the liquid level balance in the ink cartridge is maintained by the operation of the liquid supply peristaltic pump 604 and the liquid return peristaltic pump 606. In some embodiments, the return flow rate of the liquid return peristaltic pump 606 is greater than the flow rate of the liquid supply peristaltic pump 604.

[0080] The following will be combined Figure 7 The power supply and control system 700 of the printing unit is described in detail. Figure 7 FIG. 7 is a schematic diagram showing a power supply and control system 700 according to an embodiment of the present invention. Figure 7 As shown, the power supply and control system 700 includes, for example, a control device (e.g., a computer 702, a main control unit 704, first sub-control units 706-1 through Nth sub-control units 706-N), a power supply (e.g., a first power supply 710 and a second power supply 712), an inter-board communication unit 720, and a network cable 722. The computer 702 is used to issue printing task signals and printing parameters. The main control unit 704 is used to generate control instructions for controlling the ink cartridge liquid supply system, the ink cartridge air supply system, the upper air knife and lower air duct air supply systems, the scanning motion of the pre-treatment liquid printing unit, and the printing unit based on the printing task signals and printing parameters from the computer 702. Furthermore, the main control unit 704 is used to generate target trigger signals for triggering the vibration device arrays of each printing unit based on received encoder signals 714. The first power supply 710 is used to provide power to the main control unit 704. The second power supply 712 is used to provide power to the first sub-control units 706-1 through Nth sub-control units 706-N. The inter-board communication unit 720 is used for data exchange between the main control unit 704 and each sub-control unit, as well as data exchange between each sub-control unit. The first sub-control unit 706-1 through the Nth sub-control unit 706-N are respectively configured on the first through Nth nozzles and are used to provide corresponding target trigger signals to the vibration device arrays of the corresponding nozzles, thereby driving the vibration devices in the vibration device arrays of the corresponding nozzles to vibrate.

[0081] The following combination Figure 2 and Figure 8 A method 800 for printing is described. Figure 8 FIG. 8 is a flow chart of a method 800 for printing according to some embodiments of the present invention. It should be understood that the method 800 may be implemented in, for example, Figure 2 The method 800 is performed at the pre-treatment liquid printing unit 204 and the print printing unit 206. The method 800 may also include additional actions not shown and / or may omit actions shown, and the scope of the present invention is not limited in this respect.

[0082] At step 802, the control device 212 determines whether it has detected that the object to be printed has arrived at the first printing position. If the control device 212 has not detected that the object to be printed has arrived at the first printing position, the process continues to wait at step 802. It should be understood that method 800 further includes, before step 802, controlling the liquid supply system of the pre-treatment liquid cartridge to supply the pre-treatment liquid to the cartridge of the pre-treatment liquid printing unit.

[0083] The first printing position is, for example, the printing position of the pre-treatment liquid printing unit 204. For example, the control device 212 determines whether the predetermined area of the object to be printed on which the target pattern is to be sprayed has reached the first printing position. If the control device 212 determines that the predetermined area of the object to be printed on which the target pattern is to be sprayed has not reached the first printing position, the control device 212 continues to wait at step 802, i.e., waits for the predetermined area of the object to be printed to continue to move toward the printing position of the pre-treatment liquid printing unit 204.

[0084] At step 804, if the control device 212 detects that the object to be printed reaches the first printing position, it outputs a first target trigger signal to the first vibration device array of the pre-treatment liquid printing unit, so as to drive the first needle array of the pre-treatment liquid printing unit based on the vibration of the first vibration device array to spray the pre-treatment liquid to a predetermined area of the object to be printed under the drive of the first vibration device array.

[0085] Regarding the pre-treatment liquid printing unit 204, it is, for example, Figures 3A to 3C , the printing unit shown in 4A to 4D. The pre-treatment liquid printing unit 204 includes one or more nozzles, each nozzle including: a first vibration device array (such as the vibration device array described above), a first nozzle array (such as the nozzle array described above) and an ink cartridge (such as the ink cartridge described above). The first vibration device array is used to vibrate based on the received first target trigger signal, and each vibration device in the first vibration device array includes a piezoelectric ceramic unit. Each piezoelectric ceramic unit is arranged on one side of a metal sheet. A nozzle in the first nozzle array is connected to the edge of each metal sheet. Each nozzle in the first nozzle array is driven by the vibration of the corresponding vibration device in the vibration device array to output the pre-treatment liquid from the ink cartridge. The ink cartridge is connected to the nozzle in the first nozzle array for providing pre-treatment liquid or post-treatment liquid to the nozzle. In some embodiments, the pre-treatment liquid printing unit 204 is composed of, for example, a 42-needle nozzle. As Figure 2 As shown, the pre-treatment liquid printing unit 204 is installed at the front end of the printing printing unit 206 (i.e., the digital printing nozzle) through the crossbeam 214. The number of nozzles included in the pre-treatment liquid printing unit 204 can be combined and arranged according to the actual application needs of the printing printing unit 206. When the number of nozzles included in the pre-treatment liquid printing unit 204 is more than two, the more than two nozzles can be spliced longitudinally so as to be arranged in a single row, or can be spliced transversely (i.e., two by two facing each other or facing each other), or can be combined with longitudinal splicing and transverse splicing (for example, the nozzles are arranged in several rows transversely, and each row is composed of several nozzles spliced longitudinally).

[0086] The first target trigger signal is a signal output by a control unit included in the control device 212 and disposed at the pre-treatment liquid jetting unit 204, having a certain trigger frequency (for example, but not limited to, 1000 Hz) and a trigger period (for example, but not limited to, 1 ms) for triggering the vibration of the first vibrating device array. The first target trigger signal can be, for example, a sine wave, a triangular wave, or other trigger signal.

[0087] For example, one of the positive and negative poles of the first target trigger signal output by the control unit configured at the pre-treatment liquid printing unit 204 is applied to the side of the metal plate without the coating material, and the other of the positive and negative poles of the target trigger signal is applied to one side of the piezoelectric ceramic unit of the metal plate via a flexible electrode. An electric field is applied to the piezoelectric ceramic unit by the trigger signal, and the piezoelectric ceramic unit included in each vibration device in the first vibration device array undergoes mechanical deformation under the action of the first target trigger signal, driving the metal plate to move, and then the metal plate drives the corresponding spray needle in the first spray needle array to vibrate at a dotting frequency (the dotting frequency is, for example, but not limited to, 200KHZ), thereby atomizing and spraying the pre-treatment liquid at the tip of the spray needle. It should be understood that the setting parameters such as the dotting frequency, the number of dots generated by the trigger signal of a single trigger cycle, and the dotting cycle can be adjusted as needed.

[0088] Regarding the predetermined area of the object to be printed, in some embodiments, it is the entire area of the object to be printed. In other embodiments, the predetermined area of the object to be printed is, for example, the target area where the graphics of the target pattern are to be sprayed and is evenly distributed (for example, with a uniformity of ±5%). That is, the pre-treatment liquid is sprayed in the area where the pattern is to be printed, and no pre-treatment liquid is sprayed in the area where the pattern is not to be printed. Thus, the present invention allows the pre-treatment liquid to be sprayed on demand according to printing needs. By spraying the pre-treatment liquid first in the area with the pattern and then spraying the dye or paint, the present invention can further save pre-treatment liquid or slurry compared to the entire sizing process of traditional digital printing. In other embodiments, the predetermined area of the object to be printed is an area defined by an edge that is 0.01mm-1mm larger than the edge of the target area where the graphics of the target pattern are to be sprayed. Thus, the present invention allows the pre-treatment liquid to be sprayed on demand. Regarding the pre-treatment liquid, it includes at least one of a water-soluble liquid, a water-soluble slurry, a non-water-soluble emulsion, an organic solvent, and an oily medium. In some embodiments, the pre-treatment liquid may be at least one of a cationic additive, an adhesive, an inorganic salt solution, a synthetic paste, a natural paste, or various compounded emulsions. The post-treatment liquid may be, for example, a waterproof coating, a darkening agent, a brightening agent, a color fixative, a softener, an antistatic agent, etc. It is particularly suitable for use with expensive special finishing agents such as fragrances, antimicrobial agents, and additives for antiviral, anti-UV, probiotic, mosquito repellent, ice-sensing, and skin-care functions.

[0089] In some embodiments, the pre-treatment liquid can also be a printing liquid for the background color of the target pattern. Thus, a pre-treatment liquid printing unit for spraying the pre-treatment liquid installed on the printing device (digital printing machine) can be used to pre-spray the liquid for the background color portion of the target pattern that exceeds a predetermined value. For example, if the control device 212 determines that there is a background color portion with an area exceeding a predetermined value in the target pattern; a liquid for spraying the background color portion is provided to the ink cartridge of the pre-treatment liquid printing unit; if the control device 212 determines that the object to be printed has reached the first printing position, a first target trigger signal is output to the first vibration device array of the pre-treatment liquid printing unit, so as to drive the first needle array of the pre-treatment liquid printing unit based on the vibration of the first vibration device array to spray the liquid for spraying the background color portion to a predetermined area of the object to be printed (the predetermined area is the area covered by the above-mentioned background color portion) under the drive of the first vibration device array. Thus, the present invention can not only make the color of the printed target pattern more layered, but also can use the pre-treatment liquid printing unit to assist in inkjet printing to further improve the printing efficiency. In some embodiments, the pre-treatment liquid printing unit can be suitable for printing disperse dye inks (including high-temperature disperse direct injection inks), acid dye inks, reactive dye inks, coating inks, inks, etc., covering all inks involved in the textile field, in addition to paper printing inks, ceramic printing inks, outdoor advertising printing inks and other digital printing fields. Various inks or printing liquids.

[0090] At step 806, the control device 212 determines whether the object to be printed has been detected arriving at the second printing position. If the control device 212 determines that the object to be printed has not been detected arriving at the second printing position, the process continues to wait at step 806. It should be understood that method 800 further includes, before step 806, controlling the liquid supply system of the ink cartridge of the printing unit to supply printing liquid to the ink cartridge of the printing unit.

[0091] The second printing position is, for example, the printing position of the decal printing unit 206. For example, the control device 212 determines whether the predetermined area of the object to be printed, to which the target pattern is to be applied, has reached the second printing position. If the control device 212 determines that the predetermined area of the object to be printed, to which the target pattern is to be applied, has not reached the second printing position, the control device 212 continues to wait at step 806, i.e., waits for the predetermined area of the object to be printed to continue moving toward the printing position of the decal printing unit 206.

[0092] At step 808, if it is detected that the object to be printed reaches the second printing position, the printing unit is driven to output the printing liquid to the object to be printed that has been sprayed with the pre-treatment liquid, so as to generate a target printing pattern on the object to be printed.

[0093] Regarding the printing unit, it can be a general digital mosaic printing unit, or it can be Figures 3A to 3C , the printing unit shown in 4A to 4D. The printing unit 206 includes one or more nozzles, each of which includes: a second vibration device array (such as the vibration device array described above), a second needle array (such as the needle array described above) and an ink cartridge. For example, when the control unit configured at the printing unit 206 determines that the predetermined area of the object to be printed reaches the second printing position based on the detection data of the sensor, the control unit outputs a second target trigger signal to the second vibration device array of the printing unit via the control unit, so as to drive the second needle array of the printing unit based on the vibration of the second vibration device array to output the printing liquid to the object to be printed sprayed with the pre-treatment liquid under the drive of the second vibration device array.

[0094] In this scheme, by combining online pretreatment liquid spraying with simultaneous printing, a dedicated sizing machine and intermediate drying equipment are eliminated between the pretreatment liquid and the printing process, enabling wet-on-wet printing. This not only improves the uniformity, permeability, and adhesion of the dye to the printed object, thereby improving the quality of digital printing. Furthermore, the simultaneous spraying of the pretreatment liquid and digital printing increases production efficiency, simplifies the process, and reduces equipment and land costs. Therefore, this invention significantly improves overall printing efficiency and quality, while simplifying the process and reducing costs.

[0095] In some embodiments, method 800 also includes: the control device 212 determines whether it is detected that the object to be printed with the target printing pattern has arrived at the third printing position; and if the control device 212 detects that the object to be printed with the target printing pattern has arrived at the third printing position, outputs a third target trigger signal to the third vibration device array of the post-processing liquid printing unit, so as to drive the third needle array of the post-processing liquid printing unit based on the vibration of the third vibration device array to spray the post-processing liquid onto the object to be printed with the target printing pattern under the drive of the third vibration device array.

[0096] Regarding the third printing position, it is, for example, the printing position of the post-processing liquid printing unit 216 .

[0097] Regarding the post-processing liquid printing unit 216, it is arranged after the printing unit 206. In some embodiments, the post-processing liquid printing unit 216 is arranged after the drying device 210 downstream of the printing unit 206. The post-processing liquid printing unit 216 can also be Figures 3A to 3C , 4A to 4D. The post-treatment liquid printing unit 216 includes one or more nozzles, each of which includes: a third vibrating device array (such as the vibrating device array described above), a third needle array (such as the needle array described above), and an ink cartridge.

[0098] The following combination Figure 9 A method 900 for printing is described. Figure 9 FIG. 9 is a flow chart showing a method 900 for determining the amount of an auxiliary agent to be sprayed simultaneously with a pre-treatment liquid according to some embodiments of the present invention. It should be understood that the method 900 may be used, for example, in Figure 2 The pre-treatment liquid printing unit 204 is described as being executed at the textile printing unit 206. The method 900 may further include additional actions not shown and / or may omit actions shown, and the scope of the present invention is not limited in this respect.

[0099] At step 902, the control device 212 determines the amount of additive to be sprayed simultaneously with the pre-treatment liquid based on the number and precision of the nozzles of the pre-treatment liquid printing unit. For example, based on the determined amount of additive, the control device 212 controls the liquid supply system of the ink cartridge of the pre-treatment liquid printing unit to supply the determined amount of additive to the ink cartridge of the pre-treatment liquid printing unit, thereby spraying the additive simultaneously with the pre-treatment liquid to further improve printing quality. Thus, the present invention can precisely control the amount of spraying additive used to improve printing quality.

[0100] As for the auxiliary agent, it includes at least one of a darkening and brightening agent, a color fastness improving agent, a pH value adjusting agent, a whitening agent, and a cationic modifier.

[0101] At step 904, the control device 212 drives the nozzle holder supporting the pre-treatment liquid printing unit and the print printing unit to cause the pre-treatment liquid printing unit and the print printing unit to perform a back-and-forth scanning motion. For example, the nozzle holder is connected to a horizontal motion device attached to a beam. When the control device 212 drives the horizontal motion device attached to the beam to perform a back-and-forth scanning motion along the beam, the horizontal motion device drives the nozzle holder, which in turn drives the pre-treatment liquid printing unit and the print printing unit to perform a back-and-forth scanning motion.

[0102] At step 906, if the control device 212 determines that the pre-treatment liquid printing unit and the print printing unit are scanning back and forth, the suction device is turned on to control the printing liquid floating on the object to be printed within the printing area.

[0103] Regarding the suction device, such as Figure 3CAs shown, it is arranged on a cover body 352 for covering the entire pre-treatment liquid printing unit. The cover body 352 is arranged outside the multiple nozzles (such as the first nozzle 302 and the second nozzle 304) of the pre-treatment liquid printing unit to cover the multiple nozzles and the printing area 356. One or more suction devices 354 are arranged on the cover body 352. It should be understood that since the pre-treatment liquid printing unit performs a back and forth scanning motion, the pre-treatment liquid or printing liquid (such as ink) sprayed in the air above the object to be printed will inevitably float around. Therefore, when the control device 212 determines that the printing unit is scanning back and forth, the suction device is turned on to control the printing liquid floating on the object to be printed within the printing area 356. As a result, the present invention can effectively avoid contamination outside the printing device.

[0104] By adopting the above-mentioned means, the present invention can not only accurately control the amount of spraying auxiliary agent used to improve the printing quality, but also effectively avoid contamination outside the printing equipment.

[0105] While various embodiments of the present disclosure have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0106] The terms used in this document are selected to best explain the principles of the embodiments, practical applications or technical improvements in the market, or to enable other ordinary technicians in this technical field to understand the embodiments disclosed in this document.

[0107] The above are merely optional embodiments of the present disclosure and are not intended to limit the present disclosure. Those skilled in the art will readily appreciate that the present disclosure may be modified and varied in various ways. Any modifications, equivalent replacements, improvements, and the like made within the spirit and principles of the present disclosure shall be included within the scope of protection of the present disclosure.

Claims

1. A printing unit, which is used to spray a pre-treatment liquid or a post-treatment liquid, characterized in that: The printing unit includes one or more nozzles, each nozzle including: a vibration device array, configured to vibrate based on the received target trigger signal, each vibration device in the vibration device array comprising a piezoelectric ceramic unit; a spray needle array, each spray needle in the spray needle array being driven by the vibration of a corresponding vibrating device in the vibrating device array to output a pre-treatment liquid or a post-treatment liquid from the ink cartridge; and The ink cartridge is connected to the spray needles in the spray needle array and is used to provide pre-treatment liquid or post-treatment liquid to the spray needles.

2. The printing unit according to claim 1, characterized in that: Each nozzle includes at least two parallel arrays of spray needles, and the corresponding spray needles of the at least two parallel arrays of spray needles are staggered at a predetermined interval in the longitudinal direction of the spray needle array, so as to improve the printing accuracy of the printing unit.

3. The printing unit according to claim 1, characterized in that: The printing unit includes multiple nozzles, at least two of the multiple nozzles are spliced horizontally or vertically, and the positioning pins of the at least two nozzles spliced horizontally are staggered by a predetermined distance in the longitudinal direction of the nozzle array, so that the corresponding nozzles included in the at least two nozzles spliced horizontally are staggered by a predetermined distance in the longitudinal direction of the nozzle array.

4. The printing unit according to claim 1, characterized in that: Each sprinkler also includes: The nozzle cover is set on both sides of the ink cartridge to protect the nozzle array; An upper air knife is provided on the upper portion of the nozzle cover plate, and an air knife tuyere of the upper air knife outputs air with a first predetermined air pressure along a first flow guide direction; and The lower air knife is arranged in the accommodating space jointly defined by the lower part of the ink cartridge and the lower part of the nozzle cover plate. The air knife outlet of the lower air knife outputs or inhales air with a second predetermined air pressure along the second guide direction. The first guide direction is different from the second guide direction.

5. The printing unit according to claim 4, characterized in that: The first flow guiding direction is perpendicular to the spray needle, and the second flow guiding direction is parallel to the spray needle.

6. The printing unit according to claim 1, characterized in that: The ink cartridge includes a treatment liquid inlet, a treatment liquid outlet, an air inlet interface and a nozzle needle interface. The air inlet interface is connected to the ink cartridge air supply system. The ink cartridge air supply system includes: A safety bottle, one end of which is connected to the air inlet port of the ink cartridge, and the other end of which is directly or indirectly connected to a negative pressure generator to prevent the negative pressure from sucking the pre-treatment liquid or the post-treatment liquid into the negative pressure pipeline; The negative pressure generator is used to generate negative pressure to balance the ink cartridge and the spray needle liquid level to prevent the spray needle from dripping pre-treatment liquid or post-treatment liquid.

7. The printing unit according to claim 6, wherein: The cartridge air supply system also includes: a positive-negative pressure conversion solenoid valve, wherein one input end of the positive-negative pressure conversion solenoid valve is connected to the negative pressure generator, the other input end of the positive-negative pressure conversion solenoid valve is connected to the first pressure regulating valve, and the output end of the positive-negative pressure conversion solenoid valve is connected to the safety bottle; and The first gas source is connected to the first pressure regulating valve and the second pressure regulating valve respectively. The second pressure regulating valve is connected to the negative pressure generator. The first pressure regulating valve is used to provide positive pressure when cleaning the printing unit.

8. The printing unit according to claim 7, characterized in that: The treatment liquid inlet and the treatment liquid outlet are connected to the ink cartridge liquid supply system, which includes: a liquid supply peristaltic pump, arranged between the liquid supply container and the filter; a liquid return peristaltic pump, arranged between the liquid supply container and the treatment liquid outlet of the ink cartridge; a filter connected to the ink supply solenoid valve; and Ink supply solenoid valve, connected to the processing liquid inlet of the ink cartridge.

9. The printing unit according to claim 1, characterized in that: Also includes: The moisturizing device is used to prevent the spray needle from being blocked when the printing unit is not in use, and the moisturizing device includes an elastomer.

10. A method for printing, characterized in that: include: If it is detected that the object to be printed reaches the first printing position, a first target trigger signal is output to the first vibration device array of the pre-treatment liquid printing unit, so that the first needle array of the pre-treatment liquid printing unit is driven by the vibration of the first vibration device array to spray the pre-treatment liquid onto a predetermined area of the object to be printed, wherein the pre-treatment liquid printing unit is a printing unit according to any one of claims 1 to 9; as well as If it is detected that the object to be printed reaches the second printing position, the printing unit is driven to output the printing liquid to the object to be printed sprayed with the pre-treatment liquid, so as to generate a target printing pattern on the object to be printed.

11. The method according to claim 10, characterized in that Driving the printing unit to output the printing liquid to the object to be printed which has been sprayed with the pre-treatment liquid includes: A second target trigger signal is output to the second vibration device array of the print printing unit, so as to drive the second nozzle array of the print printing unit based on the vibration of the second vibration device array. Under the drive of the second vibration device array, the printing liquid is output to the object to be printed that is sprayed with the pretreatment liquid. The print printing unit and the pretreatment liquid printing unit are arranged on the beam included in the printing equipment.

12. The method according to claim 10, characterized in that The method further comprises: If it is detected that the object to be printed with the target printing pattern reaches the third printing position, a third target trigger signal is output to the third vibration device array of the post-processing liquid printing unit, so as to drive the third needle array of the post-processing liquid printing unit based on the vibration of the third vibration device array. Under the drive of the third vibration device array, the post-processing liquid is sprayed onto the object to be printed with the target printing pattern. The post-processing liquid printing unit is a printing unit according to any one of claims 1 to 9.

13. The method according to claim 12, wherein At least one of the pre-treatment liquid printing unit and the post-treatment liquid printing unit is formed by horizontally and / or vertically splicing a plurality of nozzles, and the method further includes at least one of the following: Determining the amount of auxiliary agents to be sprayed simultaneously with the pre-treatment liquid based on the number and accuracy of the nozzles of the pre-treatment liquid printing unit, wherein the auxiliary agents include at least one of a color darkening and brightening agent, a color fastness enhancer, a whitening agent, a pH adjuster, a cationic modifier, a penetrant, a dispersant, a surfactant, an inorganic salt, an anti-migration agent, a hydrophilic agent, a humectant, and a urea substitute; and The nozzle frame for supporting the pre-treatment liquid printing unit and the print printing unit is driven to drive the pre-treatment liquid printing unit and the print printing unit to scan back and forth.

14. The method according to claim 10, characterized in that The pretreatment liquid includes at least one of a water-soluble liquid, a water-soluble slurry, a water-soluble emulsion, an organic solvent, and an oily medium.

15. The method according to claim 10, characterized in that The predetermined area of the object to be printed on which the pre-treatment liquid is sprayed is the target area on which the graphics in the target pattern are to be sprayed and is evenly distributed.

16. The method according to claim 13, characterized in that The method further comprises: In response to determining that the pre-treatment liquid printing unit and the print printing unit are scanning back and forth, the air suction device is turned on to control the printing liquid floating on the object to be printed within the printing area.

17. The method according to claim 10, characterized in that The method further comprises: The drying device is controlled to dry the object to be printed with the target printing pattern generated thereon.

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