Circulating bubble discharging and ink supplying system and method special for ink-jet printing

Abstract

The invention discloses a circulation bubble discharging ink supply system and method special for ink-jet printing, and relates to the technical field of ink-jet printing, the ink supply system comprises a spray head assembly, one end of the spray head assembly is connected with a liquid inlet pipeline, and the other end of the liquid inlet pipeline is connected with a buffer bottle; the buffer bottle is also connected with a liquid conveying pipeline, and the other end of the liquid conveying pipeline is connected with a liquid storage bottle for storing ink; the other side of the spray head assembly is further connected with a liquid return pipeline, the other end of the liquid return pipeline is connected with the buffer bottle, the spray head assembly comprises a nozzle, the nozzle is connected with the liquid inlet pipeline and the spray head assembly through an ink jet channel, and an electric control valve is arranged between the ink jet channel and the liquid inlet pipeline and the spray head assembly; according to the invention, tiny bubbles can be completely discharged, the phenomena of ink interruption, ink flying or ink droplet deviation and the like in the initial stage of ink-jet printing are avoided, and the printing quality and consistency are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of inkjet printing, and in particular to a circulating bubble removal and ink supply system and method dedicated to inkjet printing. Background Art

[0002] Inkjet printing is a non-contact digital printing technology that creates text, images, or patterns by precisely spraying tiny ink droplets onto surfaces such as paper, plastic, and fabric. Its core principle is computer-controlled ink jetting, achieving high-precision and efficient printing.

[0003] Gravity or negative pressure ink supply is widely used in industrial printing. This method uses a liquid level difference or a vacuum source to stably deliver ink to the printhead, achieving continuous inkjet. Bubbles must be removed before printing. During printing, as the ink is gradually consumed, the buffer bottle level drops, requiring additional ink.

[0004] In actual application, the existing ink supply system for inkjet printing has the following defects:

[0005] 1. Incomplete bubble removal before printing: Traditional printing systems mostly rely on manual operation or simple air pressure flushing to remove bubbles, which cannot form an effective circulation flow path. Especially for long-distance and complex bends in the piping system, tiny bubbles are difficult to be completely expelled and often remain in the buffer bottle or the front section of the nozzle channel. In the initial stage of printing, ink breakage, ink flying or ink drop deviation are prone to occur, seriously affecting print quality and consistency.

[0006] 2. Pressure fluctuations during printing: In a negative pressure ink supply system, as ink is gradually consumed, the liquid level in the reservoir continues to drop. This change in the height of the liquid column causes system negative pressure fluctuations. Because the printhead is highly sensitive to ink supply pressure, even small pressure changes can cause droplet volume drift and image distortion, which is particularly prone to process defects in high-precision coating or printing of precision functional materials. Summary of the Invention

[0007] The present invention provides a circulating bubble removal and ink supply system and method for inkjet printing, which can solve the following problems existing in the prior art:

[0008] 1) Traditional printing systems mostly rely on manual operation or simple air pressure flushing to remove bubbles, which cannot form an effective circulation flow path. In particular, for long-distance, complex and bendy piping systems, tiny bubbles are difficult to be completely expelled and often remain in the buffer bottle or the front end of the nozzle channel. In the initial stage of printing, phenomena such as ink breakage, ink flying or ink drop deviation are prone to occur; 2) In the negative pressure ink supply system, as the ink is gradually consumed, the liquid level in the liquid storage bottle continues to drop, and the change in the height of the liquid column causes the system negative pressure to fluctuate. Since the nozzle is highly sensitive to the ink supply pressure, even a small pressure change will cause the ink drop volume to drift and the imaging to be distorted, which is more likely to lead to process defects, especially in high-precision coating or precision functional material printing scenarios.

[0009] A circulating bubble removal and ink supply system for inkjet printing, comprising a nozzle assembly, one end of which is connected to a liquid inlet pipeline, and the other end of which is connected to a buffer bottle;

[0010] The buffer bottle is also connected to an infusion pipeline, and the other end of the infusion pipeline is connected to a liquid storage bottle for storing ink;

[0011] The other side of the nozzle assembly is also connected to a liquid return pipeline, the other end of which is connected to a buffer bottle. The nozzle assembly includes a nozzle, which is connected to the liquid inlet pipeline and the nozzle assembly through an inkjet channel. An electric control valve is provided between the inkjet channel, the liquid inlet pipeline and the nozzle assembly.

[0012] Wherein, a liquid return module is provided on the liquid return pipeline, and the liquid return module is used to circulate the ink transported by the liquid inlet pipeline to the buffer bottle through the liquid return pipeline.

[0013] Preferably, a liquid inlet terminal is provided on one side of the nozzle assembly, one end of the liquid inlet terminal is connected to the liquid inlet channel provided in the nozzle assembly, and the other end is connected to the liquid inlet pipeline; a liquid return terminal is provided on the other side of the nozzle assembly, one end of the liquid return terminal is connected to the liquid return channel provided in the nozzle assembly;

[0014] The nozzle is connected to the liquid inlet channel and the liquid return channel, and the electric control valve is arranged in the inkjet channel.

[0015] Preferably, the end of the return line away from the nozzle assembly is connected to the infusion line, and the connection ends of the two are located on the side of the infusion line close to the buffer bottle;

[0016] Wherein, the infusion pipeline is an inverted U-shaped structure.

[0017] Preferably, the liquid return module includes an infusion pump arranged on the infusion pipeline, and the infusion pump is arranged at a position between the end of the liquid return pipeline and the buffer bottle.

[0018] Preferably, the infusion pipeline is provided with a first solenoid valve, which is arranged between the end of the return liquid pipeline and the liquid storage bottle;

[0019] Wherein, a second solenoid valve is provided on the liquid inlet pipeline; and a third solenoid valve is provided in the liquid return pipeline.

[0020] Preferably, the buffer bottle is provided with a first air pressure branch pipe, one end of the first air pressure branch pipe away from the buffer bottle is connected to the air pressure main pipe, and the end of the air pressure main pipe is connected to the air source assembly.

[0021] Preferably, the liquid storage bottle is further connected to a second air pressure branch pipe, and one end of the second air pressure branch pipe away from the liquid storage bottle is connected to the air pressure main pipe.

[0022] Preferably, the air source assembly includes an air source switching valve arranged at the end of the air pressure main pipe, and the other end of the air source switching valve is connected to the positive pressure air source;

[0023] Wherein, a fourth solenoid valve is further provided between the air pressure main pipes.

[0024] Preferably, the gas source assembly further includes a negative pressure gas source connected to the gas source switching valve.

[0025] A method for circulating bubble removal and ink supply for inkjet printing, applied to the above-mentioned circulating bubble removal and ink supply system for inkjet printing, comprises the following steps:

[0026] Ink pre-filling: The air source switching valve is switched to connect to the positive pressure air source, the fourth solenoid valve and the second solenoid valve are opened, and the first solenoid valve and the third solenoid valve are closed; the positive pressure air source pushes the ink through the buffer bottle and flows into the nozzle assembly and pipeline, completing the ink pre-filling;

[0027] Slow-pressure circulation and bubble removal: Close the fourth solenoid valve, open the first, second and third solenoid valves, start the infusion pump to form a closed-loop circulation, and the ink flows at a low speed to effectively remove residual microbubbles in the system;

[0028] Positive pressure ink pressing again: the air source switching valve maintains positive pressure, opens the fourth solenoid valve and the second solenoid valve, closes the first solenoid valve and the third solenoid valve, and further uses positive pressure to remove trace residual bubbles to ensure that the bubbles in the system are completely eliminated;

[0029] Refilling: Open the first solenoid valve, close the second, third and fourth solenoid valves, and replenish the ink from the storage bottle to the buffer bottle to ensure the liquid level.

[0030] Switch to negative pressure and prepare for printing: The air source switching valve is switched to connect to the negative pressure air source, the fourth solenoid valve, the second solenoid valve, and the third solenoid valve are opened, and the first solenoid valve is closed. The system establishes a stable negative pressure and enters the printing operation state.

[0031] The present invention provides a circulating bubble removal and ink supply system and method for inkjet printing, which has the following beneficial effects:

[0032] 1) Before the nozzle assembly of the present invention performs inkjet printing, in order to discharge the remaining bubbles in each pipeline and the nozzle assembly, the electric control valve in the present invention is in a closed state, the inkjet channel is disconnected from the liquid inlet pipeline and the liquid return pipeline, and when the liquid inlet pipeline transports the ink in the buffer bottle to the nozzle assembly, the ink is transported to the liquid return pipeline, and finally re-transported to the buffer bottle via the liquid return pipeline. Therefore, before inkjet printing, the present invention circulates the ink in the liquid inlet pipeline and the liquid return pipeline, thereby completely discharging the tiny bubbles attached to the liquid inlet pipeline and the liquid return pipeline, thereby avoiding the bubbles from affecting normal inkjet. In particular, for long-distance and complexly curved pipeline systems, the present invention can completely discharge the tiny bubbles, avoiding the occurrence of ink breakage, ink flying or ink drop deviation in the initial stage of inkjet printing, effectively improving the printing quality and consistency;

[0033] 2) During the inkjet printing process of the present invention, the air source switching valve switches its connection with the negative pressure air source, and at the same time closes the first solenoid valve, and opens the second solenoid valve, the third solenoid valve and the fourth solenoid valve, so that the air source assembly establishes a negative pressure state. Since the liquid storage bottle and the buffer bottle are simultaneously connected to the same negative pressure source, the air pressure in the two bottles is kept consistent. In this state, liquid replenishment can be controlled by the infusion pump at a flow rate, and there is no air pressure difference to interfere with the buffer bottle pressure, thereby realizing true "zero disturbance constant pressure liquid supply"; this method is suitable for industrial coating application scenarios where the nozzle assembly has extremely high requirements for ink droplet weight accuracy, and fields with extremely high requirements for pressure stability, and can significantly improve printing consistency and system reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic structural diagram of ink pre-filling in a circulating bubble removal ink supply system for inkjet printing provided by the present invention;

[0035] Figure 2 A schematic diagram of the structure of a slow-pressure circulating bubble removal system for inkjet printing provided by the present invention;

[0036] Figure 3 A schematic diagram of the structure of a positive pressure ink pressurization system for inkjet printing provided by the present invention;

[0037] Figure 4 A schematic structural diagram of a liquid replenishing system for circulating bubble removal and ink supply dedicated to inkjet printing provided by the present invention;

[0038] Figure 5 A schematic structural diagram of inkjet printing in a circulating bubble removal and ink supply system dedicated to inkjet printing provided by the present invention;

[0039] Figure 6 This is a structural schematic diagram of a nozzle assembly in a circulating bubble removal and ink supply system dedicated to inkjet printing provided by the present invention.

[0040] Description of reference numerals:

[0041] 100. Nozzle assembly; 101. Liquid inlet terminal; 102. Liquid return terminal; 103. Liquid inlet channel; 104. Liquid return channel; 105. Electric control valve; 106. Inkjet channel; 107. Nozzle; 200. Buffer bottle; 201. Liquid inlet pipeline; 202. Second solenoid valve; 203. Liquid return pipeline; 204. Third solenoid valve; 300. Liquid storage bottle; 301. Second air pressure branch; 302. Infusion pipeline; 303. Flow sensor; 304. First solenoid valve; 305. Infusion pump; 306. First air pressure branch; 400. Air source switching valve; 401. Negative pressure air source; 402. Positive pressure air source; 403. Fourth solenoid valve; 404. Air pressure main pipe. DETAILED DESCRIPTION

[0042] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0043] Example 1

[0044] like Figures 1 to 2 as well as Figure 6 As shown, an embodiment of the present invention provides a circulating bubble removal and ink supply system dedicated to inkjet printing, including a nozzle assembly 100, one end of the nozzle assembly 100 is connected to a liquid inlet pipeline 201, and the other end of the liquid inlet pipeline 201 is connected to a buffer bottle 200; specifically, this embodiment can transport the ink temporarily stored in the buffer bottle 200 to the nozzle assembly 100 through the liquid inlet pipeline 201 to achieve inkjet printing.

[0045] In this embodiment, the buffer bottle 200 is further connected to an infusion line 302, and the other end of the infusion line 302 is connected to the liquid storage bottle 300 for storing ink. It can be explained that in this embodiment, the ink to be inkjet printed can be stored in the liquid storage bottle 300 in advance. When ink supply is needed, the ink in the liquid storage bottle 300 is transported to the buffer bottle 200 through the infusion line 302. Accordingly, as the ink in the buffer bottle 200 is output, this embodiment can transport ink to the buffer bottle 200 in real time through the infusion line 302 to replenish the buffer bottle 200 in a timely manner.

[0046] In addition, this embodiment does not impose any limitation on the volumes of the buffer bottle 200 and the liquid storage bottle 300 , as long as the actual application requirements of the ink supply system are met.

[0047] See also Figure 1 and Figure 6The other side of the nozzle assembly 100 is also connected to a return liquid pipeline 203, and the other end of the return liquid pipeline 203 is connected to the buffer bottle 200. The nozzle assembly 100 includes a nozzle 107, and the nozzle 107 is connected to the liquid inlet pipeline 201 and the nozzle assembly 100 through an inkjet channel 106. An electric control valve 105 is set between the inkjet channel 106 and the liquid inlet pipeline 201 and the nozzle assembly 100. Among them, a return liquid module is provided on the return liquid pipeline 203, and the return liquid module is used to circulate the ink transported by the liquid inlet pipeline 201 through the return liquid pipeline 203 to the buffer bottle 200 (see Figure 2 );

[0048] It can be explained that, before the nozzle assembly 100 of this embodiment performs inkjet printing, in order to discharge the residual bubbles in each pipeline and the nozzle assembly 100, the electronically controlled valve 105 in this embodiment is in a closed state, and the inkjet channel 106 is disconnected from the liquid inlet pipeline 201 and the liquid return pipeline 203. When the liquid inlet pipeline 201 transports the ink in the buffer bottle 200 to the nozzle assembly 100, the ink is transported to the liquid return pipeline 203, and finally re-transported to the buffer bottle 200 through the liquid return pipeline 203. Therefore, before inkjet printing, this embodiment circulates the ink in the liquid inlet pipeline 201 and the liquid return pipeline 203, thereby completely discharging the tiny bubbles attached to the liquid inlet pipeline 201 and the liquid return pipeline 203, so as to avoid the bubbles from affecting normal inkjet printing. In particular, for long-distance and complexly bent pipeline systems, this embodiment can completely discharge the tiny bubbles, avoid the occurrence of ink breakage, ink flying or ink drop deviation in the initial stage of inkjet printing, and effectively improve the printing quality and consistency.

[0049] It should also be noted that after the ink circulates for a period of time, this embodiment opens the electronically controlled valve 105 so that the inkjet channel 106 is synchronously connected to the liquid inlet pipe 201 and the nozzle 107, so that the ink transported by the liquid inlet pipe 201 can be transported to the nozzle 107, thereby realizing inkjet printing.

[0050] In addition, as a further solution of this embodiment, the setting height of the buffer bottle 200 is greater than the setting height of the nozzle assembly 100; specifically, this embodiment sets the setting position of the buffer bottle 200 and the nozzle assembly 100 with a certain height difference, and the ink can be stably delivered to the nozzle through the liquid level height difference, without the need to use other power sources for infusion.

[0051] Example 2

[0052] Based on Example 1, please refer to Figure 1 and Figure 6In order to connect the nozzle assembly 100 with the liquid inlet pipeline 201 and the liquid return pipeline 203, a liquid inlet terminal 101 is provided on one side of the nozzle assembly 100, one end of the liquid inlet terminal 101 is connected to the liquid inlet channel 103 provided in the nozzle assembly 100, and the other end is connected to the liquid inlet pipeline 201, and a liquid return terminal 102 is provided on the other side of the nozzle assembly 100, one end of the liquid return terminal 102 is communicated with the liquid return channel 104 provided in the nozzle assembly 100, wherein the nozzle 107 is connected to the liquid inlet channel 103 and the liquid return channel 104, and the electric control valve 105 is arranged in the inkjet channel 106; it can be explained that when the liquid inlet pipeline 201 is infused, the ink is first transported to the liquid inlet channel 103 through the liquid inlet terminal 101, and then transported to the liquid return channel 104, and finally output to the liquid return pipeline 203 through the liquid return terminal 102, completing a cycle.

[0053] In addition, this embodiment does not limit the specific structure and model of the electric control valve 105, as long as it meets the reversing infusion requirements in this embodiment.

[0054] In this embodiment, the end of the return liquid pipeline 203 away from the nozzle assembly 100 is connected to the infusion pipeline 302, and the connection ends of the two are located on the side of the infusion pipeline 302 close to the buffer bottle 200, wherein the infusion pipeline 302 has an inverted U-shaped structure; it should be noted that when the ink is transported from the return liquid pipeline 203 to the buffer bottle 200, it is first transported to the infusion pipeline 302 and then flows back to the buffer bottle 200 through the infusion pipeline 302.

[0055] As a further solution of this embodiment, the liquid return module includes an infusion pump 305 arranged on the infusion pipeline 302, and the infusion pump 305 is arranged between the end of the liquid return pipeline 203 and the buffer bottle 200; specifically, when the ink is circulated, the infusion pump 305 can be started, and the infusion pump 305 can drive the ink to flow at a low speed between the liquid inlet pipeline 201 and the liquid return pipeline 203 to discharge tiny bubbles remaining in the system.

[0056] In this embodiment, when the infusion pump 305 is performing circulating infusion, in order to prevent the ink from flowing back from the infusion tube 302 to the liquid storage bottle 300, a first solenoid valve 304 is provided on the infusion pipeline 302, and the first solenoid valve 304 is arranged between the end of the return liquid pipeline 203 and the liquid storage bottle 300; specifically, when the ink is circulated, this embodiment can cut off the infusion tube 302 through the first solenoid valve 304, so that the ink is only transported in the direction of the buffer bottle 200 to avoid backflow.

[0057] See also Figure 1 and Figure 3In order to replenish the ink in the liquid storage bottle 300 into the buffer bottle 200, in this embodiment, the ink in the liquid storage bottle 300 can be delivered to the buffer bottle 200 through the infusion tube 302; accordingly, in order to prevent the ink in the buffer bottle 200 from being re-extracted through the liquid inlet pipeline 201 and the liquid return pipeline 203, in this embodiment, a second solenoid valve 202 is provided on the liquid inlet pipeline 201; it can be explained that, during the process of replenishing liquid to the buffer bottle 200, the infusion pump 305 of this embodiment can disconnect the liquid inlet pipeline 201 in advance through the second solenoid valve 202 to prevent the ink in the buffer bottle 200 from flowing from the liquid inlet pipeline 201 to the nozzle assembly 100 during the replenishment process.

[0058] Accordingly, during normal inkjet printing, as the ink in the liquid inlet pipe 201 is transported toward the inkjet channel 106, in order to prevent the ink from entering the liquid return pipe 203 and flowing back, in this embodiment, reference may be made to FIG. Figure 1 , a third solenoid valve 204 is provided in the liquid return pipeline 203; specifically, in the process of inkjet printing in this embodiment, the liquid return pipeline 203 can be disconnected in advance by the third solenoid valve 204 to prevent ink from flowing back into the liquid return pipeline 203.

[0059] As a further solution of this embodiment, in order to promote the flow of ink from the buffer bottle 200 to the nozzle assembly 100, a first air pressure branch pipe 306 is provided on the buffer bottle 200. The end of the first air pressure branch pipe 306 away from the buffer bottle 200 is connected to the air pressure main pipe 404, and the end of the air pressure main pipe 404 is connected to the air source assembly. It can be explained that in this embodiment, when it is necessary to transport the ink in the buffer bottle 200 to the nozzle assembly 100, a positive pressure can be supplied to the air pressure main pipe 404 through the air source assembly. The positive pressure is transmitted to the buffer bottle 200 by the first air pressure branch pipe 306, and the ink in the buffer bottle 200 can be pressed into the liquid inlet pipe 201 under the action of pressure.

[0060] Furthermore, in order to replenish the ink in the liquid storage bottle 300 and transfer it to the buffer bottle 200, please refer to Figure 1 and Figure 4 The liquid storage bottle 300 is also connected to a second air pressure branch pipe 301, and the end of the second air pressure branch pipe 301 away from the liquid storage bottle 300 is connected to the air pressure main pipe 404; it can be explained that when it is necessary to replenish liquid to the buffer bottle 200, the first solenoid valve 304 is closed, and positive pressure is generated by the air source component. The positive pressure is transmitted to the liquid storage bottle 300 through the air pressure main pipe 404 and the second air pressure branch pipe 301. Under the action of the positive pressure, the ink in the liquid storage bottle 300 can be transported to the buffer bottle 200 through the infusion pipe 302.

[0061] In this embodiment, the air source assembly includes an air source switching valve 400 arranged at the end of the air pressure main pipe 404, and the other end of the air source switching valve 400 is connected to the positive pressure air source 402; wherein, a fourth solenoid valve 403 is also provided between the air pressure main pipe 404; specifically, in this embodiment, when replenishing pressure to the liquid storage bottle 300 or the buffer bottle 200, the fourth solenoid valve 403 is opened, and the positive pressure can be delivered to the air pressure main pipe 404 through the positive pressure air source 402.

[0062] Furthermore, in a negative pressure ink supply system, as the ink is gradually consumed, the liquid level in the buffer bottle 200 continues to drop, and the change in the height of the liquid column causes fluctuations in the system negative pressure. In order to reduce the sensitivity of the nozzle assembly 100 to the height of the ink supply pressure, in this embodiment, the air source assembly further includes a negative pressure air source 401 connected to the air source switching valve 400; the air source switching valve 400 of this embodiment can switch its connection with the positive pressure air source 402 or the negative pressure air source 401 in real time, so as to facilitate real-time adjustment of the air pressure main 404 to generate positive or negative pressure;

[0063] It can be explained that during the inkjet printing process, the gas source switching valve 400 switches its connection with the negative pressure gas source 401, and at the same time closes the first solenoid valve 304, opens the second solenoid valve 202, the third solenoid valve 204 and the fourth solenoid valve 403, so that the gas source assembly establishes a negative pressure state. Since the liquid storage bottle 300 and the buffer bottle 200 are connected to the same negative pressure source at the same time, the air pressure in the two bottles is kept consistent. In this state, liquid replenishment can be controlled by the infusion pump 305 to control the flow rate, and there is no air pressure difference to interfere with the pressure of the buffer bottle 200, realizing true "zero disturbance constant pressure liquid supply"; this method is suitable for industrial coating application scenarios where the nozzle assembly 100 has extremely high requirements for ink droplet weight accuracy, and fields with extremely high requirements for pressure stability, and can significantly improve printing consistency and system reliability.

[0064] A special circulating bubble removal and ink supply method for inkjet printing, comprising the following steps:

[0065] See also Figure 1 S1. Ink pre-filling: The air source switching valve 400 is switched to connect with the positive pressure air source 402, the fourth solenoid valve 403 and the second solenoid valve 202 are opened, and the first solenoid valve 304 and the third solenoid valve 204 are closed; the positive pressure air source 402 pushes the ink through the buffer bottle 200 and flows into the nozzle assembly 100 and the pipeline, completing the ink pre-filling;

[0066] See also Figure 2 S2, slow pressure circulation and bubble removal: close the fourth solenoid valve 403, open the first solenoid valve 304, the second solenoid valve 202, and the third solenoid valve 204, start the infusion pump 305 to form a closed loop circulation, the ink flows at a low speed, and effectively removes the residual micro bubbles in the system;

[0067] See also Figure 3S3. Press ink with positive pressure again: the air source switching valve 400 maintains positive pressure, the fourth solenoid valve 403 and the second solenoid valve 202 are opened, the first solenoid valve 304 and the third solenoid valve 204 are closed, and the positive pressure is further used to remove trace residual bubbles to ensure that the bubbles in the system are completely eliminated;

[0068] See also Figure 4 , S4, replenishing liquid: open the first solenoid valve 304, close the second solenoid valve 202, the third solenoid valve 204, and the fourth solenoid valve 403, and replenish ink from the liquid storage bottle 300 to the buffer bottle 200 to ensure the liquid level height.

[0069] See also Figure 5 , S5, switch to negative pressure and prepare for printing: the gas source switching valve 400 is switched to connect with the negative pressure gas source 401, the fourth solenoid valve 403, the second solenoid valve 202, and the third solenoid valve 204 are opened, and the first solenoid valve 304 is closed. The system establishes a stable negative pressure and enters the printing operation state.

[0070] Example 3

[0071] This embodiment does not use the infusion pump 305 for ink circulation. Instead, the control system drives the air source switching valve 400 to alternately apply positive and negative pressures to the top of the liquid storage bottle 300 or the buffer bottle 200, thereby forming periodic air pressure fluctuations.

[0072] This method forms a micro-fluid disturbance in the pipeline, which can drive the bubbles in the ink supply path to migrate along the pressure gradient, and finally push them to the exhaust port or reflux channel set at both ends of the nozzle assembly 100, thereby preventing the bubbles from entering the nozzle 107. This embodiment is suitable for small inkjet systems with compact structure or without circulation channels, and can effectively complete bubble transfer before printing, thereby improving the initial printing stability.

[0073] Example 4

[0074] In this embodiment, a micro-flow sensor 303 is installed between the infusion tubes 302 to monitor the infusion flow rate in real time. The control system collects the flow rate signal of this section of the path in real time and uses this signal to calculate the actual ink consumption per unit time. Based on the calculated result, the infusion pump 305 is controlled to accurately replenish the same amount of ink, implementing a "consumption-based" ink supply strategy. This system maintains a stable pressure within the buffer bottle 200 without the need for a liquid level sensor or isobaric structure, ensuring consistent liquid supply during continuous inkjet. This system is suitable for high-frequency or multi-nozzle systems and offers high responsiveness and structural flexibility.

[0075] The above disclosures are only a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A special circulating bubble removal and ink supply system for inkjet printing, comprising a nozzle assembly (100), characterized in that: One end of the spray head assembly (100) is connected to a liquid inlet pipeline (201), and the other end of the liquid inlet pipeline (201) is connected to a buffer bottle (200); The buffer bottle (200) is also connected to a liquid infusion pipeline (302), and the other end of the liquid infusion pipeline (302) is connected to a liquid storage bottle (300) for storing ink; The other side of the nozzle assembly (100) is further connected to a liquid return pipeline (203), the other end of which is connected to the buffer bottle (200), the nozzle assembly (100) comprises a nozzle (107), the nozzle (107) is connected to the liquid inlet pipeline (201) and the nozzle assembly (100) through an inkjet channel (106), and an electric control valve (105) is provided between the inkjet channel (106), the liquid inlet pipeline (201) and the nozzle assembly (100); The liquid return pipeline (203) is provided with a liquid return module, and the liquid return module is used to circulate the ink transported by the liquid inlet pipeline (201) to the buffer bottle (200) through the liquid return pipeline (203).

2. A circulating bubble removal and ink supply system for inkjet printing according to claim 1, characterized in that: A liquid inlet terminal (101) is provided on one side of the nozzle assembly (100), one end of the liquid inlet terminal (101) is connected to a liquid inlet channel (103) provided in the nozzle assembly (100), and the other end is connected to a liquid inlet pipeline (201); a liquid return terminal (102) is provided on the other side of the nozzle assembly (100), one end of the liquid return terminal (102) is communicated with a liquid return channel (104) provided in the nozzle assembly (100); The nozzle (107) is connected to the liquid inlet channel (103) and the liquid return channel (104), and the electric control valve (105) is arranged in the inkjet channel (106).

3. A circulating bubble removal and ink supply system for inkjet printing as claimed in claim 2, characterized in that: The end of the liquid return line (203) away from the nozzle assembly (100) is connected to the liquid infusion line (302), and the connection ends of the two are located on the side of the liquid infusion line (302) close to the buffer bottle (200); Wherein, the infusion pipeline (302) is an inverted U-shaped structure.

4. A circulating bubble removal and ink supply system for inkjet printing as claimed in claim 3, characterized in that: The liquid return module comprises an infusion pump (305) arranged on the infusion pipeline (302), and the infusion pump (305) is arranged at a position between the end of the liquid return pipeline (203) and the buffer bottle (200).

5. The inkjet printing dedicated circulating bubble removal and ink supply system as claimed in claim 3, characterized in that: The infusion pipeline (302) is provided with a first electromagnetic valve (304), and the first electromagnetic valve (304) is arranged between the end of the return liquid pipeline (203) and the liquid storage bottle (300); Wherein, a second solenoid valve (202) is provided on the liquid inlet pipeline (201); and a third solenoid valve (204) is provided in the liquid return pipeline (203).

6. The inkjet printing dedicated circulating bubble removal and ink supply system according to claim 1, characterized in that: The buffer bottle (200) is provided with a first air pressure branch pipe (306), one end of the first air pressure branch pipe (306) away from the buffer bottle (200) is connected to the air pressure main pipe (404), and the end of the air pressure main pipe (404) is connected to the air source component.

7. A circulating bubble removal and ink supply system for inkjet printing according to claim 6, characterized in that: The liquid storage bottle (300) is also connected to a second air pressure branch pipe (301), and one end of the second air pressure branch pipe (301) away from the liquid storage bottle (300) is connected to the air pressure main pipe (404).

8. A circulating bubble removal and ink supply system for inkjet printing according to claim 7, characterized in that: The air source assembly includes an air source switching valve (400) disposed at the end of an air pressure main pipe (404), and the other end of the air source switching valve (400) is connected to a positive pressure air source (402); A fourth electromagnetic valve (403) is further provided between the air pressure main pipes (404).

9. The inkjet printing dedicated circulating bubble removal and ink supply system according to claim 6, characterized in that: The gas source assembly further comprises a negative pressure gas source (401) connected to the gas source switching valve (400).

10. A special circulating bubble removal and ink supply method for inkjet printing, characterized in that: The inkjet printing dedicated circulating bubble removal and ink supply system as claimed in claim 5 comprises the following steps: Ink pre-filling: the air source switching valve (400) is switched to connect with the positive pressure air source (402), the fourth solenoid valve (403) and the second solenoid valve (202) are opened, and the first solenoid valve (304) and the third solenoid valve (204) are closed; the positive pressure air source (402) pushes the ink through the buffer bottle (200) and flows into the nozzle assembly (100) and the pipeline, completing the ink pre-filling; Slow-pressure circulation and bubble removal: close the fourth solenoid valve (403), open the first solenoid valve (304), the second solenoid valve (202), and the third solenoid valve (204), start the infusion pump (305) to form a closed-loop circulation, and the ink flows at a low speed to effectively remove the residual microbubbles in the system; Positive pressure ink pressing again: the air source switching valve (400) maintains positive pressure, the fourth solenoid valve (403) and the second solenoid valve (202) are opened, the first solenoid valve (304) and the third solenoid valve (204) are closed, and the positive pressure is further used to remove trace residual bubbles to ensure that the bubbles in the system are completely eliminated; Liquid replenishment: open the first electromagnetic valve (304), close the second electromagnetic valve (202), the third electromagnetic valve (204), and the fourth electromagnetic valve (403), and the ink is replenished from the liquid storage bottle (300) to the buffer bottle (200) to ensure the liquid level. Switch to negative pressure and prepare for printing: the gas source switching valve (400) is switched to connect with the negative pressure gas source (401), the fourth solenoid valve (403), the second solenoid valve (202), and the third solenoid valve (204) are opened, and the first solenoid valve (304) is closed. The system establishes a stable negative pressure and enters the printing operation state.

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