Spray head for target object spraying

Abstract

The present application relates to a spray head for target object spraying. The spray head comprises one or more spray head units, each of which comprises a liquid supply unit for supplying a liquid to be sprayed to a flow channel, a flow channel in communication with a flow channel connection port of each capillary tube in a capillary tube group, and one or more capillary tube groups, each of which comprises a plurality of capillary tubes, each of which comprises a main body portion, a flow channel connection port and a liquid outlet port, the flow channel connection port and the liquid outlet port being provided at two end portions of the main body portion respectively, the liquid outlet port being shaped and dimensioned such that the liquid to be sprayed is output from the liquid outlet port in a continuous output manner. The present application can have a lower manufacturing cost, and can avoid liquid spray emission and improve liquid spray efficiency.

Description

Technical Field

[0001] The present invention relates generally to inkjet printing technology, and in particular to a printhead for spraying a target object. Background Art

[0002] In existing nozzles, for example, for coloring or spraying a target object (e.g., fabric), ultrasonic atomization technology is used to atomize the liquid to be sprayed (e.g., ink) so as to be printed on the target object. Since the atomization of the liquid to be sprayed requires additional energy consumption, and the atomized droplets (e.g., ink droplets) that are not attached to the target object require a matching absorption device to reduce the impact on the environment. Although the above-mentioned existing nozzles based on ultrasonic atomization technology have technical advantages such as saving the liquid to be sprayed and the printing pattern is precise and controllable, since they need to be configured with a transducer for realizing ultrasonic atomization and an absorption device for absorbing excess atomized ink droplets, the manufacturing cost is relatively high. In addition, the efficiency of atomized liquid coloring or spraying is poor.

[0003] In summary, the disadvantages of conventional nozzles are: high manufacturing cost, problems of flying liquid (eg, flying ink) discharge, and poor liquid (eg, ink) ejection efficiency. Summary of the Invention

[0004] The present invention provides a spray head for spraying a target object, which has a low manufacturing cost, can avoid flying liquid discharge and improve the liquid spraying efficiency.

[0005] According to a first aspect of the present invention, a nozzle for spraying a target object is provided, the nozzle comprising one or more nozzle units, each nozzle unit comprising: a liquid supply unit for supplying liquid to be sprayed to a flow channel; a flow channel, the flow channel being connected to a flow channel connection port of each capillary in a capillary group; and one or more rows of capillary groups, each row of capillary groups comprising a plurality of capillaries, each capillary comprising a main body portion, a flow channel connection port and a liquid outlet, the flow channel connection port and the liquid outlet being respectively arranged at two ends of the main body portion, the shape and size of the liquid outlet being configured such that the liquid to be sprayed is output from the liquid outlet in a continuous output manner.

[0006] In some embodiments, the continuous output is in the form of a liquid column.

[0007] In some embodiments, the liquid supply unit includes a plurality of liquid inlets, and the flow channel is configured to adjust flow rates of the plurality of liquid inlets so that flow rates of the liquid to be sprayed at the locations of the plurality of capillaries are different from each other.

[0008] In some embodiments, the flow channel is configured as a longitudinal groove, the bottom surface of the longitudinal groove is an arc surface, an opening connected to the flow channel connection port of the capillary is provided on the arc surface, and the height of the longitudinal groove is less than or equal to a predetermined height threshold.

[0009] In some embodiments, the two ends of the main body of the capillary are respectively the flow channel connection end and the liquid outlet end, the outer diameter of the first end of the liquid outlet end is larger than the outer diameter of the second end of the liquid outlet end, the first end of the liquid outlet end is connected to the main body, and the second end of the liquid outlet end is provided with the liquid outlet.

[0010] In some embodiments, an angle between a side wall of the liquid outlet end of the capillary tube and a radial cross section of the capillary tube is greater than or equal to 10 degrees.

[0011] In some embodiments, the flow channel connection port is located at a first end of the flow channel connection end, and at least a portion of the liquid outlet end is configured as a tapered tube.

[0012] In some embodiments, the ratio of the inner diameter and the outer diameter of the second end of the liquid outlet is configured to have a difference from a transition ratio threshold that is less than a predetermined range, and the transition ratio threshold corresponds to a transition liquid outlet flow rate, which is the corresponding liquid outlet flow rate when the liquid to be sprayed is output from the liquid outlet in a dripping manner to a continuous spraying manner.

[0013] In some embodiments, the liquid supply unit also includes: a liquid distributor, including a distributor inlet and multiple distributor outlets; multiple flow limiting valves, the input end of each flow limiting valve is connected to the corresponding distributor outlet among the multiple distributor outlets; and multiple groups of proportional valves, the output end of each flow limiting valve is connected to the corresponding group of proportional valves among the multiple groups of proportional valves.

[0014] In some embodiments, the plurality of proportional valves included in each group of the plurality of proportional valves are respectively connected to the plurality of liquid inlets in the corresponding spray head unit.

[0015] In some embodiments, each nozzle unit further includes: a base plate having a plurality of mounting holes for mounting a capillary group and limiting the spacing between the capillaries; a flow channel plate having one or more of the flow channels configured on a first surface of the flow channel plate; and a side wall, wherein the side wall, the base plate, and the second surface of the flow channel plate form a accommodating space for the capillary group.

[0016] In some embodiments, each nozzle unit includes: a plurality of sealing rings, each of the plurality of sealing rings is arranged on the outside of the flow channel connecting end of the corresponding capillary tube to seal the capillary tube.

[0017] In some embodiments, the sealing ring is disposed in a sealing ring snap groove on the second side of the flow channel plate, and the flow channel is configured on the first surface of the flow channel plate.

[0018] In some embodiments, the bottom plate of the showerhead unit has a splicable structure for enabling splicing between the bottom plates of adjacent showerhead units.

[0019] In some embodiments, the shape, size of the liquid outlet, and the distance between the liquid outlet and the target object are configured such that the liquid to be sprayed in the continuous liquid column segment, but not in the turbulent segment of liquid column to liquid drop, is provided onto the target object.

[0020] The 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 application, and is not intended to limit the scope of the application. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A longitudinal sectional view of a showerhead for target object spraying according to some embodiments of the application is shown.

[0022] Figure 2 A side view of a capillary tube set containing space according to some embodiments of the application is shown.

[0023] Figure 3 A top view of a flow channel plate according to some embodiments of the application is shown.

[0024] Figure 4 A transverse sectional view of a showerhead unit according to some embodiments of the application is shown.

[0025] Figure 5 A bottom view of a showerhead unit according to some embodiments of the application is shown.

[0026] Figure 6 A partial enlarged view of a capillary tube according to some embodiments of the application is shown.

[0027] Figure 7 A sectional view of a capillary tube partial according to some embodiments of the application is shown.

[0028] Figure 8 A structural schematic view of a capillary tube according to some embodiments of the application is shown.

[0029] Figure 9 A fluid property equivalent circuit schematic view of a flow channel and capillary tube set according to some embodiments of the application is shown.

[0030] Figure 10 A schematic view of continuous output and drop output modes according to some embodiments of the application is shown.

[0031] Figure 11A schematic diagram of a liquid supply unit according to some embodiments of the present application is shown.

[0032] Figure 12 A schematic diagram of a showerhead unit according to some embodiments of the present application is shown.

[0033] In the various drawings, like or corresponding elements are denoted by like or corresponding reference numerals. DETAILED DESCRIPTION

[0034] Preferred embodiments of the present application will be described herein below with reference to the accompanying drawings. While preferred embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0035] The term "comprising" and variations thereof as used herein are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. The term "or" as used herein is intended to mean "and / or" unless otherwise indicated. The term "based on" means "based, at least in part, on" unless otherwise indicated. The terms "one example embodiment" and "an example embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one additional embodiment." The terms "a first," "a second," etc. can refer to different or the same objects.

[0036] As described previously, the conventional showerhead has the disadvantages of high manufacturing cost and liquid mist emission.

[0037] To at least partially address one or more of the above-mentioned problems and other potential problems, example embodiments of the present application propose a showerhead for target object spraying, by having the showerhead comprise one or more showerhead units, each showerhead unit comprising: a liquid supply unit for supplying a liquid to be sprayed to a flow channel; the flow channel in communication with a flow channel connection port of each capillary tube in a capillary tube group; and one or more capillary tube groups, each capillary tube group comprising a plurality of capillary tubes, each capillary tube comprising a main body portion, a flow channel connection port, and a liquid outlet port, the flow channel connection port and the liquid outlet port being disposed at two end portions of the main body portion, respectively, the liquid outlet port being shaped and sized to cause the liquid to be sprayed to be output from the liquid outlet port in a continuous output manner. By replacing the liquid spraying manner based on the transducer technology of ultrasonic atomization with the capillary tube group that causes the liquid to be sprayed to be output from the liquid outlet port in a continuous output manner, the present application significantly reduces the manufacturing cost, has higher liquid spraying efficiency, and does not cause liquid mist emission. Thus, the present application can have lower manufacturing cost and avoid liquid mist emission.

[0038] The following description is provided in connection with Figure 1 An exemplary showerhead 100 for target object spraying is illustrated. Figure 1 A longitudinal cross-sectional view of a spray head 100 for spraying a target object according to some embodiments of the present invention is shown.

[0039] The showerhead 100 includes, for example, one or more showerhead units. Figure 1 The figure shows an example of a nozzle including a nozzle unit. Figure 1 As shown, each nozzle unit includes a liquid supply unit, a flow channel 110, one or more rows of capillary tube groups 120 ( Figure 1 Two rows of capillary tubes are shown in the example).

[0040] Regarding the liquid supply unit, it is used to supply the liquid to be sprayed to the flow channel. The liquid supply unit supplies the liquid to be sprayed to the flow channel in the form of a constant current source. In some embodiments, the liquid supply unit includes a plurality of liquid inlets 150. Figure 1 As shown, each nozzle unit includes, for example, three liquid inlets 150 (a first liquid inlet 150-1 located on the left side of the flow channel, a second liquid inlet 150-2 located in the middle of the flow channel, and a third liquid inlet 150-3 located on the right side of the flow channel). In some embodiments, the liquid supply unit of each nozzle unit includes, for example, two liquid inlets 150, such as Figure 11 It should be understood that the liquid supply unit may also include other numbers of liquid inlets.

[0041] The liquid to be sprayed may be, for example, functional liquids such as ink, dyeing liquid, chemical solution, and treatment liquid. In some embodiments, the liquid to be sprayed is ink for coloring a target fabric.

[0042] The flow channel 110 is used to supply the liquid to be sprayed from the liquid supply unit to the capillary tube group 120. The flow channel 110 is communicated with the flow channel connection port of each capillary tube in the capillary tube group 120. Figure 1 Only the portion of the flow channel 110 exposed by the liquid inlet 150 is shown.

[0043] Regarding the target object, it is, for example, a target fabric, a target substrate, and the like.

[0044] Regarding the capillary group 120, it is used to output the liquid to be sprayed from the flow channel to the target object. Each nozzle unit includes one or more rows of capillary groups 120. Each row of capillary groups 120 includes multiple capillaries. Each capillary includes: a main body, a flow channel connection port and a liquid outlet. The flow channel connection port and the liquid outlet are respectively arranged at the two ends of the main body, and the shape and size of the liquid outlet are configured so that the liquid to be sprayed is output from the liquid outlet in a continuous output manner. Regarding the continuous output method, it is, for example, a liquid column output method, rather than a discontinuous method like droplets. It should be understood that since the liquid to be sprayed is output from the liquid outlet in a continuous output manner, the present invention can significantly improve the liquid spraying efficiency.

[0045] The continuous output method may be, for example, a continuous liquid column output method. Figure 10 Schematic diagram showing continuous output and drip output according to some embodiments of the present invention. Figure 10 As shown in the left part of , the liquid to be sprayed is discharged from the liquid outlet of the capillary in a continuous output manner. Figure 10 As shown in the left part of FIG, the liquid to be sprayed continuously output from the liquid outlet of the capillary includes, for example: a continuous liquid column section 111, a turbulent section 113 where the liquid column changes into liquid droplets, and liquid droplets 117. Figure 10 As shown in the right part of the figure, the liquid to be sprayed is discharged from the liquid outlet of the capillary in a non-continuous manner of dripping. The liquid to be sprayed discharged from the liquid outlet of the capillary in a dripping manner includes, for example: a droplet generating area 119 and droplets 117. It should be understood that the shape and size of the liquid outlet of the present invention are configured so that the liquid to be sprayed is discharged in a non-continuous manner. Figure 10 The liquid is discharged from the liquid outlet in a continuous manner as shown on the left side of the figure. In some embodiments, the shape, size, and distance between the liquid outlet and the target object of the present invention are configured so that the liquid to be sprayed is provided to the target object in the continuous liquid column section 111 rather than the turbulent section 113 where the liquid column changes to droplets. This can significantly improve the spraying effect on the target object.

[0046] It should be understood that when the liquid to be sprayed flows in the flow channel and the capillary tube, there will be flow resistance in the flow channel and the capillary tube. The magnitude of the flow resistance is generally determined by the viscosity of the fluid, the length and radius of the flow channel. Figure 9 FIG. 1 shows a schematic diagram of an equivalent circuit of fluid characteristics of a flow channel and a capillary group according to some embodiments of the present invention. Figure 9 As shown, it includes N flow channel segments and N capillaries (N is, for example, a positive integer. In some embodiments, N is an even number). In the flow channel, the flow channel segment between each two openings has a certain flow resistance, such as Figure 9 R in L1 Indicates the flow resistance of the first flow channel section (i.e., the flow channel before the first capillary); R LN Indicates the flow resistance of the Nth flow channel segment. It should be understood that the flow resistance of the entire flow channel is similar to that of multiple flow channel segments "in series". Each flow channel segment also has "inductive reactance" (inductive reactance indicates the property of the flow channel that hinders the flow change of the fluid flow, such as Figure 9 Medium L L1 Indicates the inductive reactance of the first flow channel section; L LN Indicates the inductive reactance of the Nth flow channel segment). Each capillary connected to the opening of the flow channel also has a flow resistance (such as Figure 9 Medium R Z1 Indicates the flow resistance of the first capillary; R ZN Indicates the flow resistance of the Nth capillary), inductive reactance (such as Figure 9 Medium L Z1Indicates the inductive reactance of the first capillary; L ZN Indicates the inductive reactance of the Nth capillary). In addition, each group of flow channel segments and capillaries also has a "capacitive reactance" represented by the gas and liquid therein (the capacitive reactance indicates the storage capacity of the fluid represented by the gas and liquid, such as Figure 9 Middle C LZ1 Indicates the capacitive reactance of the first flow channel segment and the first capillary; C LZN Indicates the capacitive reactance of the Nth flow channel section and the Nth capillary). In addition, Figure 9 I in L Indicates a constant current source connected to one end (e.g., the left end) of the flow channel; I M Indicates a constant current source connected to the middle of the flow channel (for example, connected near the N / 2 capillary); I R Indicates the constant current source connected to the other end (e.g. right end) of the flow channel. Figure 9 As shown, one end of the three constant current sources is connected and "grounded" (such as Figure 9 (The inverted triangle in the figure indicates grounding.) It should be understood that in the fluid characteristic equivalent circuit, "voltage" corresponds to fluid pressure; "current" corresponds to fluid flow. "Grounding" is equivalent to being connected to atmospheric pressure. It should be understood that the liquid outlet of each capillary is connected to atmospheric pressure, which is equivalent to "grounding" one end of the capillary.

[0047] The following uses formulas (1) to (3) to illustrate how to calculate inductive reactance, capacitive reactance, and flow resistance.

[0048]

[0049] In the above formula (1), L LN Represents the inductive reactance of the Nth flow channel section. ρ represents the density of the liquid to be sprayed. LN Represents the length of the Nth flow channel section. R represents the cross-sectional area of ​​the Nth flow channel segment (taking a circular cross-sectional area as an example). It should be understood that the inductive reactance of a capillary tube is calculated in a similar manner.

[0050]

[0051] In the above formula (2), C LZN Represents the capacitive reactance of the Nth flow channel segment and the Nth capillary. V LZN represents the volume of the Nth flow channel segment and the Nth capillary tube. B represents the bulk modulus of the Nth flow channel segment and the Nth capillary tube.

[0052]

[0053] In the above formula (3), R LN Represents the flow resistance of the Nth flow channel section. μ represents the viscosity of the liquid to be sprayed.LN Represents the length of the Nth flow channel segment. LN Represents the radius of the cross section of the Nth flow channel segment (using a circular cross section as an example). As can be seen from the above formula (3), the radius of the cross section of the flow channel segment has a relatively large impact on the flow resistance. A small change in the radius will bring about a significant change in the flow resistance. It should be understood that the flow resistance of the capillary is calculated in a similar manner. In addition, formulas (1) to (3) use a flow channel and / or capillary with a circular cross section as an example. The cross sections of the flow channel and capillary can also have other shapes.

[0054] In some embodiments, the flow resistance of the flow channel is configured to adjust the flow rates of the multiple liquid inlets so that the flow rates of the liquid to be sprayed at the locations of the multiple capillaries are different from each other. Figure 9 I in L Indicates a constant current source connected to one end (eg, the left end) of the flow channel, which is, for example, connected to the first liquid inlet 150 - 1 located on the left side of the flow channel. Figure 9 I in M Indicates a constant current source connected to the middle of the flow channel, which is, for example, connected to the second liquid inlet 150-2 located in the middle of the flow channel. Figure 9 I in RIndicates a constant current source connected to the other end (e.g., the right end) of the flow channel, which is, for example, connected to the third liquid inlet 150-3 located on the right side of the flow channel. In some embodiments, if the flow resistance of the flow channel is relatively large, in a steady state, a linear change in the flow rate at the capillary can be achieved by separately controlling the inlet flow rates of the first liquid inlet 150-1 located on the left side of the flow channel, the second liquid inlet 150-2 located in the middle of the flow channel, and the third liquid inlet 150-3 located on the right side of the flow channel. For example, the flow rate at each capillary changes gradually from left to right. For example, the inlet flow rate of the first liquid inlet 150-1 located on the left side of the flow channel is 100% of the predetermined value; the inlet flow rate of the second liquid inlet 150-2 located in the middle of the flow channel is -100% of the predetermined value; and the inlet flow rate of the third liquid inlet 150-3 located on the right side of the flow channel is 100% of the predetermined value. In this case, the inlet flow rate at both ends of the flow channel is high, and the inlet flow rate in the middle is low, resulting in different flow rates at different capillaries. For another example, the liquid flow rate of the first liquid inlet 150-1 located on the left side of the flow channel is 100% of the predetermined value; the liquid flow rate of the second liquid inlet 150-2 located in the middle of the flow channel is -50% of the predetermined value; and the liquid flow rate of the third liquid inlet 150-3 located on the right side of the flow channel is 50% of the predetermined value. It should be understood that, for example, during the fabric dyeing process, the fabric will exhibit a non-uniform density across the entire width due to the pre-treatment process before entering the printing area. If the same amount of dye (i.e., liquid to be sprayed) is applied during printing, the final color of the fabric will be non-uniform. The present invention controls the liquid flow rate of multiple liquid inlets located at different positions in the flow channel to achieve different liquid flow rates at different capillaries (e.g., linear changes). This can address the non-uniform density of the fabric across the entire width by outputting different flow rates of liquid to be sprayed at different capillaries, thereby achieving uniform coloring or spraying of the entire fabric.

[0055] Regarding the main part of the capillary (such as Figure 4 The two ends at both ends of the main body are respectively the flow channel connection ends (such as Figure 4 124) and the liquid outlet end 122.

[0056] The following combination Figures 6 to 8 The structure of the liquid outlet end 122 of the capillary tube will be described in detail. Figure 6 A partially enlarged view of a capillary according to some embodiments of the present invention is shown. Figure 7 A cross-sectional view of a portion of a capillary tube according to some embodiments of the present invention is shown. Figure 8 Schematic diagram of the structure of the capillary according to some embodiments of the present invention is shown. Figure 6As shown, one end of the main body 126 of the capillary is the liquid outlet 122. The first end 127 of the liquid outlet 122 is connected to the main body 126, and the second end 128 of the liquid outlet 122 is the liquid outlet.

[0057] In some embodiments, the outer diameter of the first end 127 of the liquid outlet 122 (eg, Figure 7 and Figure 8 DN) is larger than the outer diameter of the second end 128 of the liquid outlet end 122 (e.g., Figures 6 to 8 ). This facilitates controlling the liquid flow rate at the liquid outlet. It should be understood that the outer diameter DN of the first end 127 of the liquid outlet 122 is the outer diameter of the capillary. In some embodiments, the outer diameter of the capillary is greater than or equal to 0.1 mm.

[0058] Regarding the inner diameter of the liquid outlet end 122, in some embodiments, the inner diameter (dn) of the first end 127 of the liquid outlet end 122 is equal to the inner diameter (d) of the second end 128 of the liquid outlet end 122, as shown in FIG. Figure 7 In some embodiments, the inner diameter (dn) of the first end 127 of the liquid outlet 122 is larger than the inner diameter (d) of the second end 128 of the liquid outlet 122, as shown in FIG. Figure 8 In other embodiments, the inner diameter of the first end 127 of the liquid outlet end 122 is equal to the inner diameter of the second end 128 of the liquid outlet end 122, and the outer diameter of the first end 127 of the liquid outlet end 122 is equal to the outer diameter of the second end 128 of the liquid outlet end 122. In some embodiments, the inner diameter (d) of the second end 128 of the liquid outlet end 122 is equal to the outer diameter (D) of the second end 128 of the liquid outlet end 122. In some embodiments, the inner diameter (d) of the second end 128 of the liquid outlet end 122 is greater than or equal to 0.02 mm.

[0059] In some embodiments, the outer wall profile of the liquid outlet end 122 is configured as an arc, a step, or a segment. In some embodiments, at least a portion of the liquid outlet end 122 is configured as a tapered tube. Figure 7 As shown, the entire liquid outlet end 122 is configured as a tapered tube, for example. It should be understood that the outer diameter of the tapered tube gradually decreases, and the inner diameter of the tapered tube can remain unchanged or gradually decrease. Figure 7 As shown, in the direction extending from the first end 127 to the second end 128 (d), the outer diameter of the liquid outlet end 122 gradually decreases from the outer diameter (DN) at the first end 127 until it is reduced to the outer diameter (D) of the second end 128; at the same time, the inner diameter of the liquid outlet end 122 remains unchanged, that is, equal to the inner diameter of the second end 128. It should be understood that by configuring the liquid outlet end as a tapered tube with a constant inner diameter, it is convenient to control the liquid outlet flow rate and facilitate processing.

[0060] Figure 8The cross-sectional view in the upper right corner is an enlarged view of the area surrounded by the circle indicated by mark 121. Figure 8 As shown, a portion of the liquid outlet end 122 is configured as a tapered tube, for example, a combination of a tapered tube and a cylindrical tube. The axial height n of the tapered tube is less than or equal to the axial height of the liquid outlet end 122. The difference between the outer diameter (DN) at the first end 127 and the inner diameter (dn) of the first end 127 may or may not be equal to the difference between the outer diameter (D) of the second end 128 and the inner diameter (d) of the second end 128. As the first end 127 extends toward the second end 128 (d), the outer diameter of the liquid outlet end 122 gradually decreases from the outer diameter of the cylindrical tube end to the outer diameter (D) of the second end 128. Simultaneously, the inner diameter of the liquid outlet end 122 gradually decreases from the inner diameter (dn) of the first end 127 to the inner diameter (d) of the second end 128. It should be understood that by configuring at least a portion of the liquid outlet end as a tapered tube with decreasing inner and outer diameters, the liquid outlet flow rate can be more effectively controlled. Regarding the side wall of the liquid outlet end of the capillary, in some embodiments, as Figure 7 As shown, the angle θ between the side wall 810 of the liquid outlet end of the capillary and the radial cross section 812 of the capillary is greater than or equal to 10 degrees. In some embodiments, the angle θ is any value greater than or equal to 10 degrees and less than 90 degrees. In some embodiments, the angle θ is any value greater than or equal to 80 degrees and less than 90 degrees. By setting the angle θ within the above-mentioned angle range, the liquid output from the liquid outlet can be prevented from wetting the side of the liquid outlet end, so as to promote the formation of a continuous liquid column. It should be understood that if the liquid output from the liquid outlet wets the side of the liquid outlet end, it is easy to form an asymmetric wetting condition, which in turn has a negative impact on the output of the continuous liquid column from the liquid outlet.

[0061] like Figure 6 As shown, arrow 123 indicates the inner diameter of the second end 128 of the liquid outlet end 122, which is represented by the letter "d". Arrow 125 indicates the outer diameter of the second end 128 of the liquid outlet end 122, which is represented by the letter "D".

[0062] The following formulas (4) to (6) are used to explain the relationship between the inner diameter d and outer diameter D of the liquid outlet and the critical Weber number: relationship.

[0063]

[0064] B0=[ρgD 2 / (2σ)] 1 / 2 (5)

[0065]

[0066] In the above formula (4), represents the critical Weber number. B0 and Represents the Bond number based on the inner and outer diameters of the outlet, respectively. K represents a constant. B0 and The ratio is related to the ratio of the inner diameter to the outer diameter. In the above formulas (5) and (6), ρ represents the density of the liquid to be sprayed. σ represents the surface tension of the liquid to be sprayed. g represents the acceleration of gravity. v0 represents the flow rate of the liquid to be sprayed. D represents the inner diameter (diameter) of the capillary at the outlet. It should be understood that the Weber number is a characteristic number used in fluid mechanics, which characterizes the ratio of the deformation inertia force and the stable cohesive force when the liquid (for example, the liquid to be sprayed) flows through a fluid medium (for example, a capillary). Cohesive force is related to surface tension or interfacial tension, which prevents the increase of surface area, thereby causing deformation. Therefore, the droplets of the liquid to be sprayed will gather together due to surface tension or interfacial tension. Critical Weber number The Weber number indicates the transition from a droplet to a continuous jet (or "continuous output", for example, a liquid column) when the liquid to be sprayed, with a density ρ and a surface tension σ, passes through the liquid outlet with an inner diameter D at a flow rate v0. It should be understood that the critical Weber number The transition flow rate is associated with the transition from a dripping mode to a continuous spraying mode in which the liquid to be sprayed is output from the liquid outlet.

[0067] Regarding the transition flow rate, for example, the liquid to be sprayed is output from the liquid outlet in a manner such that Figure 10 The dripping method (or "drip output method") shown on the right side is Figure 10 The left side shows the corresponding flow rate when switching to the continuous injection mode (also called the "continuous output mode" or the "liquid column mode").

[0068] Research has shown that when the inner diameter of the capillary tube (for example, the inner diameter of the liquid outlet is equal to the inner diameter of the capillary tube) is sufficiently small, the interface of the liquid to be sprayed can stabilize into Rayleigh-Taylor instability (RT instability). In this state, the inertia of the liquid to be sprayed, the capillary action of the capillary tube, and the gravity of the liquid to be sprayed dominate over the viscosity of the liquid to be sprayed. When the inner diameter d of the liquid outlet remains unchanged, the closer the outer diameter D is to the inner diameter d (i.e., the smaller the outer diameter D), the smaller the transitional flow rate of the liquid to be sprayed from the liquid outlet when it transitions from a dripping mode to a continuous spraying mode. In some embodiments, the ratio of the inner diameter to the outer diameter of the second end of the liquid outlet is configured to differ from a transition ratio threshold value by less than a predetermined range. The transition ratio threshold value corresponds to the transitional liquid flow rate, which is the liquid flow rate corresponding to the transition from a dripping mode to a continuous spraying mode when the liquid to be sprayed is output from the liquid outlet.

[0069] like Figure 1 and Figure 2 As shown, in some embodiments, each spray head unit further includes: a bottom plate 130 , a side wall 132 , a flow channel plate 134 , and a plurality of sealing rings 140 .

[0070] The bottom plate 130 has a plurality of mounting holes for mounting the capillary tube set 120 and defining the intervals between the capillaries.

[0071] Regarding the flow channel plate 134, its first surface (eg, Figure 1 In some embodiments, the second surface of the flow channel plate 134 (e.g., Figure 1 A sealing ring snap groove for snapping the sealing ring 140 is provided on the lower surface of the flow channel plate 134.

[0072] The side wall 132, the bottom plate 130, and the second surface of the flow channel plate 134 form a space for accommodating the capillary group 120. In some embodiments, the side wall 132 includes at least a first side wall 132-1 and a second side wall 132-2 (e.g., Figure 2 shown).

[0073] Regarding the sealing ring 140, it is used to seal the capillary. In some embodiments, the number of the sealing rings is equal to the number of the capillaries. Figure 1 As shown, each sealing ring is arranged on the outside of the flow channel connecting end of the corresponding capillary tube to seal the capillary tube. Figure 1 The dotted box in the upper left corner is a partial enlarged view of the portion within the imaginary line indicated by reference numeral 102, showing each sealing ring 140 positioned outside the flow channel connection end of the corresponding capillary tube. The sealing ring is also positioned within a sealing ring snap-fit ​​groove on the second side of the flow channel plate 134.

[0074] In some embodiments, each showerhead unit further includes, for example, a top plate 138 , a sealing plate 136 , and a mounting plate 142 .

[0075] Regarding the top plate 138 , it is configured to be located on the upper surface of the spray head unit. In some embodiments, the top plate 138 is used to install one or more liquid inlets 150 .

[0076] Regarding the sealing plate 136, it is provided between the top plate 138 and the flow channel plate 134 to seal the communication space between the flow channel and the liquid inlet 150. In some embodiments, the sealing plate 136 and the top plate 138 are provided with a through hole (e.g., Figure 2 The top plate through hole 139 and the sealing plate through hole 137 are shown so as to guide the liquid to be sprayed from the liquid inlet 150 to the flow channel 110.

[0077] Regarding the mounting plate 142 , it is, for example, disposed between the flow channel plate 134 and the side wall 132 to achieve relative fixation between the flow channel plate 134 and the side wall 132 .

[0078] The following combination Figure 2 A schematic diagram illustrating the accommodation space of a capillary group. Figure 2 A side view of a receiving space of a capillary tube set according to some embodiments of the present invention is shown.

[0079] Regarding the accommodation space 135 of the capillary tube group, in some embodiments, as Figure 2 As shown, it is defined by at least sidewalls 132 (sidewalls 132 specifically include first sidewalls 132-1 and second sidewalls 132-2), the upper surface of the bottom plate 130, and the second surface (i.e., the lower surface) of the flow channel plate 134. It should be understood that each nozzle unit includes, for example, a capillary tube group accommodation space 135. Each capillary tube group accommodation space 135, for example, accommodates one or more rows of capillary tube groups. Figure 2 As shown, the capillary tube group accommodating space 135 accommodates two rows of capillary tube groups.

[0080] The following combination Figure 3 A schematic diagram illustrating the flow channel plate 134 is shown. Figure 3 A top view of a flow channel plate according to some embodiments of the present invention is shown.

[0081] like Figure 3 As shown, the flow channel plate 134 has a first surface (ie, the upper surface of the flow channel plate 134 ) and a second surface (ie, the lower surface of the flow channel plate 134 ).

[0082] For example, a plurality of flow channels 110 are disposed on the first surface of the flow channel plate 134 . Figure 3 The schematic diagram in Figure 1 schematically shows that the first surface of the flow channel plate 134 includes two flow channels. It should be understood that the number of flow channels 110 configured on the flow channel plate 134 of each nozzle unit is equal to the number of rows of capillary tube groups, and each flow channel 110 is used to provide liquid to be sprayed to the corresponding row of capillary tube groups 120. Each flow channel 110, for example, includes multiple openings, through which the flow channel is connected to the flow channel connection port of the corresponding capillary tube in the capillary tube group. In some embodiments, the flow channel plate 134 is also provided with multiple mounting holes 114 for achieving relative fixation between the flow channel plate 134 and the sealing plate 136, the mounting plate 142, and / or the sidewall 132.

[0083] Regarding the flow channel 110, in some embodiments, the flow resistance of the flow channel is configured to adjust the flow rates of the multiple liquid inlets so that the flow rates of the liquid to be sprayed at the locations of the multiple capillaries are different from each other. Figure 3As shown, reference 112-M indicates the Mth opening, which corresponds to, for example, the position of the Mth capillary tube. Reference 112-N indicates the Nth opening, which corresponds to, for example, the position of the Nth capillary tube. It should be understood that the flow resistance of flow channel 110 is configured, for example, to adjust the flow rates of the multiple liquid inlets so that the outflow rate of the liquid to be sprayed at the position of the Mth capillary tube differs from that at the position of the Nth capillary tube.

[0084] In some embodiments, the flow channel 110 is configured as a longitudinal groove, for example, with a curved bottom surface, and an opening provided on the curved surface that communicates with the flow channel connection port of the capillary. It should be understood that by configuring the bottom surface of the flow channel 110 as a curved surface, the flow channel of the present invention can reduce residual liquid to be sprayed in the flow channel.

[0085] Regarding the longitudinal grooves, for example, Figure 3 The longitudinal grooves are narrow, shallow grooves extending in the X-direction. In some embodiments, the cross-section of the longitudinal grooves is semicircular. In some embodiments, the height of the longitudinal grooves is less than or equal to a predetermined height threshold. The predetermined height threshold is, for example, but not limited to, 1 mm. For example, in some embodiments, the height of the longitudinal grooves is configured to be 0.5 mm. By making the height of the longitudinal grooves very low, that is, by configuring the longitudinal grooves as narrow, shallow grooves, the flow resistance of the flow channel can be easily controlled. In some embodiments, the width of the longitudinal grooves is, for example, 1 mm.

[0086] It should be understood that, under low flow resistance, a slight change in the flow resistance in the pipeline will significantly affect the stability of the flow rate of the liquid to be sprayed. By increasing the flow resistance of the flow channel (for example, making the flow resistance of the flow channel exceed a predetermined flow resistance threshold), the stability of the flow rate of the liquid to be sprayed output by the nozzle can be improved.

[0087] In some embodiments, the cross-sectional area of ​​the flow channel is, for example, configured to be smaller than a predetermined cross-sectional area threshold. In some embodiments, the cross-sectional area of ​​the flow channel is, for example, but not limited to, 0.5 square millimeters. In some embodiments, the cross-sectional area of ​​the flow channel is determined based on the sensitivity requirements of the flow control of the liquid to be sprayed by the nozzle. It should be understood that the flow resistance in microfluidics is mainly caused by the pressure drop and energy loss caused by the friction between the liquid and the channel wall. Experimental data show that when the viscous liquid to be sprayed is in a laminar flow state, the closer the liquid to be sprayed is to the flow channel wall, the greater its flow resistance and the corresponding flow rate; under the same pressure, the smaller the inner diameter of the flow channel, the greater the flow resistance and the lower the flow rate. Therefore, the present invention increases the flow resistance in the flow channel and reduces the flow rate by configuring the flow channel as a narrow and shallow groove and making its cross-sectional size small enough, thereby improving the sensitivity of the flow control of the liquid to be sprayed by the nozzle.

[0088] Figure 4 A transverse cross-sectional view of a showerhead unit according to some embodiments of the present invention is shown.

[0089] like Figure 3 and Figure 4 As shown, mounting holes are provided on the bottom plate 130. Mounting holes are provided on the mounting plate 142. Mounting holes are also provided on the side wall 132. A first mounting device 144 is sequentially inserted through the mounting holes on the bottom plate 130, side wall 132, and mounting plate 142, thereby securing the bottom plate 130, side wall 132, and mounting plate 142.

[0090] like Figure 4 As shown, the top plate 138, the sealing plate 136, the flow channel plate 134 and the mounting plate 142 are relatively fixed by coupling the second mounting device 146 with the mounting holes on the top plate 138, the sealing plate 136, the flow channel plate 134 and the mounting plate 142 respectively.

[0091] In some embodiments, the first mounting device 144 and the second mounting device 146 are configured as bolts, for example. In some embodiments, the first mounting device 144 and the second mounting device 146 can be coupled and decoupled.

[0092] It should be understood that the above-described mounting method facilitates local maintenance and installation. For example, the first mounting device 144 can be decoupled from the mounting holes in the bottom plate 130, the side wall 132, and the mounting plate 142, allowing for convenient removal of the bottom plate 130 and the side wall 132, thereby facilitating installation and maintenance of the capillary tubes without affecting the relative fixation between the top plate 138, the sealing plate 136, the flow channel plate 134, and the mounting plate 142. Similarly, the second mounting device 146 can be decoupled from the mounting holes in the top plate 138, the sealing plate 136, the flow channel plate 134, and the mounting plate 142, allowing for convenient removal of the top plate 138, the sealing plate 136, and the flow channel plate 134, thereby facilitating installation and maintenance of the flow channel or liquid inlet, without affecting the relative fixation between the bottom plate 130, the side wall 132, and the capillary tube assembly.

[0093] Figure 4 The dashed box in the upper right corner is an enlarged view of the partial structure within the dashed box indicated by reference numeral 148. Reference numeral 112 indicates a flow channel opening. This opening 112 is located, for example, on the bottom surface of the flow channel on the first surface 115 of the flow channel plate 134. This opening 112 communicates with the flow channel connection end of the capillary tube and is used to supply the liquid to be sprayed in the flow channel to the capillary tube via opening 112. The liquid to be sprayed supplied to the capillary tube flows sequentially through the flow channel connection end of the capillary tube, the main body 126, and finally exits through the liquid outlet at the second end (i.e., the distal end) of the liquid outlet end 122.

[0094] Figure 4The second surface 118 of the flow channel plate 134 is also shown to be provided with a sealing ring snap groove 116. The sealing ring snap groove 116 is used to snap a sealing ring 140 so that the sealing ring 140 is fixed outside the flow channel connection end of the capillary tube to seal the flow channel connection end of the capillary tube. Figure 5 A bottom view of a showerhead unit according to some embodiments of the present invention is shown.

[0095] In some embodiments, the ratio of the inner diameter and the outer diameter of the second end of the liquid outlet is configured to have a difference from a transition ratio threshold that is less than a predetermined range, and the transition ratio threshold corresponds to a transition liquid outlet flow rate, which is the corresponding liquid outlet flow rate when the liquid to be sprayed is output from the liquid outlet in a dripping manner to a continuous spraying manner.

[0096] The following combination Figure 11 The structure of the liquid supply unit of the plurality of head units will be described in detail. Figure 11 Schematic diagram of a liquid supply unit of a plurality of nozzle units according to some embodiments of the present invention is shown. Figure 11 As shown, the liquid supply unit 170 is used to provide liquid to be sprayed to the nozzle unit group 172. The nozzle unit group 172 is, for example, composed of multiple nozzle units. The liquid supply unit 170 includes a liquid distributor 180, multiple flow limiting valves 190, multiple sets of proportional valves 192, and connecting pipelines. The liquid distributor is used to distribute the liquid to be sprayed, provided via the distributor inlet 182, to each of the flow limiting valves 190 via multiple distributor outlets 184. The liquid distributor 180 includes a distributor inlet 182 and multiple distributor outlets 184. The distributor inlet 182 is, for example, connected to a constant current source to receive a constant flow of liquid to be sprayed. The multiple distributor outlets 184 are respectively connected to the multiple flow limiting valves 190. The flow limiting valves 190 are used to adjust the flow rate provided to the corresponding set of proportional valves 192 according to control instructions (such as control instructions generated based on density distribution data of a target object (e.g., fabric), such as provided by the supplier of the target object or generated based on test data of the target object). Each flow limiting valve 190 is connected to a set of proportional valves 192. A set of proportional valves 192 includes, for example, a plurality of proportional valves. Figure 11As shown, each flow limiting valve 190 is respectively connected to a group of proportional valves 192 consisting of a first proportional valve 192-1 and a second proportional valve 192-2. Different proportional valves in the same group of proportional valves are respectively connected to different liquid inlets 150 in the corresponding same nozzle unit. For example, the first proportional valve 192-1 is connected to the first liquid inlet 150-1 and is used to adjust the liquid inlet flow rate of the first liquid inlet 150-1. The second proportional valve 192-2 is connected to the second liquid inlet 150-2 and is used to adjust the liquid inlet flow rate of the second liquid inlet 150-2. By adopting the above scheme, the present invention can not only conveniently supply liquid (for example, ink) to the nozzle unit group, but also can make the flow rate of the capillaries in different nozzle units individually controlled, thereby overcoming the problem of uneven coloring or spraying caused by uneven density in the width direction of the fabric.

[0097] The following combination Figure 12 The splicing method of multiple nozzle units is specifically described. Figure 12 Schematic diagram of a nozzle unit group according to some embodiments of the present invention is shown. Figure 12 As shown, the nozzle unit group 170 includes, for example, a plurality of nozzle units (for example, the nozzle unit group 170 includes a first nozzle unit 170-1, a second nozzle unit 170-2, and a third nozzle unit 170-3). The bottom plate 130 of each nozzle unit has, for example, a spliceable structure 129 for splicing with the bottom plate of an adjacent nozzle unit. In some embodiments, the spliceable structure 129 is, for example, one or more sets of mortise and tenon joints. In other embodiments, the spliceable structure 129 is, for example, one or more sets of locking mechanisms.

[0098] By adopting the above method, the present invention can conveniently construct printing equipment of various widths, thereby meeting the coloring or spraying requirements of fabrics of different widths. It should be understood that Figure 12 The side walls and bottom plate of any nozzle unit (for example, the second nozzle unit 170-2) can be installed and disassembled independently. Therefore, the present invention can conveniently perform independent maintenance and repair on the capillary of the nozzle unit (for example, the liquid outlet of the capillary is damaged or the capillary is blocked) without the need to disassemble the entire nozzle unit.

[0099] While various embodiments of the present invention 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.

[0100] 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.

[0101] The foregoing detailed description has set forth various embodiments of the devices and / or methods via the use of specific terminology. However, embodiments thereof can be practiced with the exact description not being presented in detail. It should be understood that the references whereby specific conductive materials are named are exemplary and not limiting. It should be further understood that the specific conductive materials named are exemplary and not limiting. It should be further understood that the specific conductive materials named are exemplary and not limiting. It should be further understood that the specific conduct

Claims

1. A nozzle for spraying a target object, characterized in that: It includes one or more nozzle units, each nozzle unit includes: a liquid supply unit, for supplying the liquid to be sprayed to the flow channel; a flow channel, the flow channel being in communication with a flow channel connection port of each capillary tube in the capillary tube group; and One or more rows of capillary tube groups, each row of capillary tube groups includes a plurality of capillaries, each capillary tube includes a main body, a flow channel connection port, and a liquid outlet, the flow channel connection port and the liquid outlet are respectively provided at two ends of the main body, and the shape and size of the liquid outlet are configured so that the liquid to be sprayed is discharged from the liquid outlet in a continuous manner; The two ends of the main body of the capillary are respectively the flow channel connection end and the liquid outlet end, the first end of the liquid outlet end is connected to the main body, and the second end of the liquid outlet end is provided with the liquid outlet; the ratio of the inner diameter and the outer diameter of the second end of the liquid outlet end is configured to be less than the difference with the transition ratio threshold value within a predetermined range, and the transition ratio threshold value corresponds to the transition liquid outlet flow rate, and the transition liquid outlet flow rate is the corresponding liquid outlet flow rate when the mode of outputting the liquid to be sprayed from the liquid outlet is changed from a dripping mode to a continuous spraying mode, and the continuous output mode is a liquid column output mode.

2. The nozzle according to claim 1, characterized in that The liquid supply unit includes a plurality of liquid inlets, and the flow channel is configured to adjust the flow rates of the plurality of liquid inlets so that the flow rates of the liquid to be sprayed at the positions where the plurality of capillaries are located are different from each other.

3. The nozzle according to claim 1, characterized in that The flow channel is configured as a longitudinal groove, the bottom surface of the longitudinal groove is an arc surface, an opening connected to the flow channel connection port of the capillary is provided on the arc surface, and the height of the longitudinal groove is less than or equal to a predetermined height threshold.

4. The nozzle according to claim 1, characterized in that The outer diameter of the first end of the liquid outlet is greater than the outer diameter of the second end of the liquid outlet.

5. The nozzle according to claim 4, characterized in that: An angle between a side wall of the liquid outlet end of the capillary and a radial cross section of the capillary is greater than or equal to 10 degrees.

6. The nozzle according to claim 4, characterized in that The flow channel connection port is located at a first end of the flow channel connection end, and at least a portion of the liquid outlet end is configured as a tapered tube.

7. The nozzle according to claim 1, characterized in that The liquid supply unit also includes: a liquid distributor comprising a distributor inlet and a plurality of distributor outlets; a plurality of flow restrictor valves, an input end of each flow restrictor valve being in communication with a corresponding distributor outlet of the plurality of distributor outlets; and There are multiple groups of proportional valves, and the output end of each flow limiting valve is connected to the corresponding group of proportional valves in the multiple groups of proportional valves.

8. The nozzle according to claim 7, characterized in that The multiple proportional valves included in each group of the multiple proportional valves are respectively connected to the multiple liquid inlets in the corresponding spray head unit.

9. The nozzle according to claim 1, characterized in that Each sprinkler unit also includes: A bottom plate having a plurality of mounting holes for mounting the capillary tube group and defining the spacing between the capillaries; a flow channel plate, wherein one or more flow channels are configured on a first surface of the flow channel plate; and The side wall, the bottom plate, and the second surface of the flow channel plate form an accommodating space for the capillary group.

10. The nozzle according to claim 4, characterized in that Each sprinkler unit includes: A plurality of sealing rings, each of which is arranged on the outside of the flow channel connecting end of the corresponding capillary tube, for sealing the capillary tube.

11. The nozzle according to claim 10, characterized in that The sealing ring is arranged in a sealing ring buckle groove on the second side of the flow channel plate, and the flow channel is configured on the first surface of the flow channel plate.

12. The nozzle according to claim 9, characterized in that The bottom plate of the nozzle unit has a splicable structure for realizing splicing between the bottom plates of adjacent nozzle units.

13. The nozzle according to claim 9, characterized in that The shape, size, and distance between the liquid outlet and the target object are configured so that the liquid to be sprayed is provided onto the target object in a continuous liquid column section rather than a turbulent section where the liquid column changes into liquid droplets.

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