Apparatus and Method

Abstract

To reduce a fluid crosstalk in which pressure is transmitted to a pressure chamber.SOLUTION: A liquid discharge device includes: a passage member having a passage in which a pseudoplastic liquid flows; an actuator which applies a pressure to the liquid in the passage to cause droplets to be discharged from the passage member; and a passage sequentially circulating through a supply reservoir, a plurality of supply manifolds, a plurality of supply passages, a plurality of pressure chambers, a plurality of recovery passages, a plurality of recovery manifold, and a recovery reservoir. The passage has a passage shape such that an average viscosity of the liquid in the supply passages becomes a half of or lower than an average viscosity of the liquid in the supply manifolds when a circulation flow rate is a target flow rate to reduce fluid crosstalk.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a liquid ejection device and a liquid ejection method.

Background Art

[0002] Liquid ejection devices such as inkjet printers are known. Patent Document 1 discloses an inkjet recording device using an ink having thixotropy.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] A liquid ejection device according to one aspect of the present disclosure includes a flow path member, an actuator, and a flow rate setting unit. The flow path member has a flow path through which a pseudoplastic liquid flows. The actuator applies pressure to the liquid in the flow path to eject droplets from the flow path member. The flow rate setting unit sets the flow rate of the liquid in the flow path. The flow path includes a supply reservoir, a plurality of supply manifolds, a plurality of supply flow paths, a plurality of pressure chambers, a plurality of nozzles, a plurality of recovery flow paths, and a recovery reservoir. The supply reservoir supplies the liquid. The plurality of supply manifolds are connected to the supply reservoir, and the liquid is supplied from the supply reservoir. The plurality of supply flow paths are provided in two or more numbers for each of the plurality of supply manifolds, are each connected to any one of the plurality of supply manifolds, and the liquid is supplied from the connected supply manifold. The plurality of pressure chambers are separately connected to the plurality of supply flow paths, the liquid is supplied from the plurality of supply flow paths, and pressure is applied by the actuator. The plurality of nozzles are separately connected to the plurality of pressure chambers, and eject the liquid from the pressure chambers to the outside. The plurality of recovery flow paths are separately connected to the plurality of pressure chambers, and recover the liquid from the plurality of pressure chambers. The plurality of recovery manifolds are each connected to two or more of the plurality of recovery flow paths, and recover the liquid from the plurality of recovery flow paths. The recovery reservoir is connected to the plurality of recovery manifolds, and recovers the liquid from the plurality of recovery manifolds. The flow rate setting unit adjusts the circulation flow rate of the liquid that circulates in order through the supply reservoir, the plurality of supply manifolds, the plurality of supply flow paths, the plurality of pressure chambers, the plurality of recovery flow paths, the plurality of recovery manifolds, and the recovery reservoir to a predetermined target flow rate. The flow path has a flow path shape in which when the circulation flow rate is the target flow rate, the average viscosity of the liquid in the supply flow path is equal to or less than half of the average viscosity of the liquid in the supply manifold.

[0005] A liquid ejection method according to one aspect of the present disclosure is a liquid ejection method using the liquid ejection device, wherein the liquid has a viscosity of 0.02 Pa·s or more and 0.4 Pa·s or less when the shear rate is 1000 s -1 and a viscosity of 0.5 Pa·s or more and 50 Pa·s or less when the shear rate is 0.01 s -1 and uses a pseudoplastic fluid.

Brief Description of Drawings

[0006]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0007] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following drawings are schematic. Therefore, details may be omitted. Also, the dimensional ratios do not necessarily match the actual ones. The dimensional ratios between multiple drawings do not necessarily match either. Specific dimensions may be shown larger than the actual ones, and specific shapes may be exaggerated.

[0008] In the drawings, arrows indicating directions D1 to D6 may be attached. These directions are parallel to the ejection surface 3a described later. Also, the D2 direction and the D5 direction are, for example, directions parallel to the longitudinal direction of the head 3 described later, and from another perspective, are so-called main scanning directions. The D3 direction and the D6 direction are directions orthogonal to the D2 direction and the D5 direction. The D1 direction and the D4 direction are directions inclined with respect to the D3 direction and the D6 direction.

[0009] (Overall Configuration of Liquid Ejection Device) FIG. 1 is a diagram schematically showing a main part configuration of a liquid ejection device 1 (hereinafter sometimes referred to as “ejection device 1”) according to an embodiment.

[0010] The ejection device 1 is configured as a device that attaches a liquid to the surface of an object 101 by ejecting droplets from the ejection surface 3a of the head 3 toward the object 101, for example, like an inkjet printer. Note that the ejection surface 3a may face in any direction with respect to the vertical direction, but in the following description, for convenience, the direction in which the ejection surface 3a faces is taken as downward, and terms such as upper surface or lower surface may be used.

[0011] The specific type (use) of the ejection device 1 may be appropriate. For example, the ejection device 1 may be a device that adheres ink to a recording medium (such as paper) as the object 101 to print characters and graphics (or record information from another perspective). That is, the ejection device 1 may be a generally referred to printer. Also, for example, the ejection device 1 may be a device that adheres paint to the body of an automobile as the object 101 to decorate the body. Also, for example, the ejection device 1 may be a device that adheres a liquid containing conductive particles to a circuit board as the object 101 to form wiring.

[0012] Also, different from the illustrated example, the ejection device 1 may not be a device that adheres a liquid to the object 101. For example, the ejection device 1 may be a device that ejects a liquid chemical that reacts with the substance in the container into the container, or a device that sprays a disinfectant into the air.

[0013] As understood from the above examples of the specific types of the ejection device 1, the material, shape, and dimensions of the object 101 may be appropriate. Since FIG. 1 is a schematic diagram, the object 101 is shown as a rectangular parallelepiped. Examples of the material of the object 101 include paper, cloth, resin, metal, ceramic, and wood, as well as combinations thereof. Examples of the type of the object 101 include a recording medium (such as roll paper or sheet paper), a circuit board, clothing, a beverage container, a storage container, a housing of an electronic device, and a body of an automobile. The object 101 or the region on which the liquid is adhered may be narrower or wider than the ejection surface 3a that ejects the droplets.

[0014] Also, as can be understood from the examples of the specific types of the above-described ejection device 1, the type of liquid may also be appropriate. For example, examples of the type of liquid include ink, paint, liquid containing conductive particles, chemicals, and disinfectant solution. Ink and paint may be distinguished by the presence or absence of an organic solvent and / or the presence or absence of a function of protecting the surface of the object 101. However, such a distinction may not be made. In the following description, paint may be appropriately read as ink. The reverse is also true. Paint may contain a pigment for the purpose of coloring, or may not contain a pigment (colorless) without the purpose of coloring (for example, only for the purpose of imparting gloss and / or protecting the object 101).

[0015] The ejection device 1 has, for example, a head 3 that ejects droplets and a moving unit 5 that relatively moves the head 3 and the object 101. The head 3 has a discharge surface 3a in which a plurality of nozzles (described later) for ejecting droplets are open. The moving unit 5 relatively moves both of them along the discharge surface 3a and the surface of the object 101 while maintaining a state in which the discharge surface 3a and the surface of the object 101 face each other. The direction of the relative movement is, for example, the D3 direction or the D6 direction. As can be understood from an inkjet printer which is a specific example of the ejection device 1, droplets are ejected from the discharge surface 3a in synchronization with the above-described relative movement, so that the droplets are attached to a region having an area larger than the area of the arrangement region of the plurality of nozzles.

[0016] Also, the ejection device 1 has, for example, a tank 7 that stores liquid. The head 3 has a supply port 3b for supplying liquid from the tank 7 to the head 3 and a recovery port 3c for recovering liquid from the head 3 to the tank 7. That is, the liquid circulates through the head 3 and the tank 7. By circulating the liquid in this way, for example, the probability that the liquid stays in the head 3 is reduced. As a result, the probability that the retained liquid solidifies or the components in the retained liquid precipitate is reduced. Further, in the present embodiment, by circulating the liquid, as will be described later, the shear rate of the liquid can be adjusted, and thus the viscosity of the liquid can be adjusted.

[0017] The ejection device 1 has a circulation operating unit 9 that applies pressure to the liquid so that the liquid circulates, and a control unit 11 that controls each unit (for example, the head 3, the moving unit 5, and the circulation operating unit 9). Note that the combination of the circulation operating unit 9 and the control unit 11 may be regarded as a flow rate setting unit 13 that sets the flow rate of the liquid circulating through the head 3 (hereinafter referred to as the circulation flow rate). The circulation flow rate may be considered, for example, to be the same as the flow rate of the liquid flowing out from the recovery port 3c to the outside of the head 3.

[0018] The ejection device 1 may have only one head 3 (and tank 7) like a monochrome printer, or may have a plurality of heads 3 (and a plurality of tanks 7) that eject different types of liquids like a color printer. Further, the ejection device 1 may have a plurality of heads 3 that eject the same type of liquid. The plurality of heads 3 that eject the same type of liquid are advantageous, for example, in shortening the time for attaching the liquid to a certain area or improving the dot density. In the following description, for the sake of convenience, only one head 3 will be mentioned.

[0019] (Moving unit) The moving unit 5 can, for example, relatively move the object 101 with respect to the head 3 in at least one of the D3 direction and the D6 direction. This direction is, as described above, the moving direction when ejecting droplets, and is a so-called sub-scanning direction. The moving unit 5 may be capable of realizing relative movement between the head 3 and the object 101 in other directions than the D3 direction and the D6 direction. Examples of other directions in which relative movement may be realized include the D2 direction and the D5 direction that are orthogonal to the D3 direction and the D6 direction, and the direction orthogonal to the ejection surface 3a (the direction in which the head 3 and the object 101 approach each other and the direction in which both are separated from each other). Further, the moving unit 5 may be capable of realizing relative rotation between the head 3 and the object 101.

[0020] In the absolute coordinate system, the moving unit 5 may move only the object 101, or only the head 3, or both. Also, the specific configuration of the moving unit 5 may be appropriately set according to the specific type of the ejection device 1.

[0021] For example, when the ejection device 1 is a so-called line printer, the moving unit 5 may be configured as a device that conveys a recording medium (e.g., paper) as the object 101. The device may include, for example, a plurality of rollers that contact the recording medium to generate frictional force and an electric motor that rotates the plurality of rollers. Also, for example, when the ejection device 1 is a so-called serial printer, the moving unit 5 may include a device that conveys the recording medium as the object 101 in a predetermined conveyance direction and a device that moves the head 3 in a direction perpendicular to the conveyance direction and along the recording medium.

[0022] Also, for example, the ejection device 1 may include a belt conveyor that conveys any type of object 101. Also, for example, the ejection device 1 may include a movable table on which any type of object 101 is placed. Also, for example, the ejection device 1 may include an industrial robot that moves any type of object 101 and / or an industrial robot that moves the head 3. Examples of industrial robots include vertical articulated robots (narrow sense articulated robots), scalar robots, orthogonal robots, and parallel link robots.

[0023] (Tank and Circulation Operating Unit) The tank 7 and the circulation operating unit 9 may be the same as those in a known inkjet printer that circulates a liquid, or may be an application of the known tank and circulation operating unit.

[0024] For example, the tank 7 may be configured to accommodate the liquid supplied to the head 3 and the liquid recovered from the head 3 in the same space. Further, the tank 7 may be configured to accommodate the liquid supplied to the head 3 and the liquid recovered from the head 3 in separate spaces and allow the liquid to flow from the latter space to the former space. In this case, the tank 7 may have one tank partitioned by a partition wall to have two spaces, or may have two tanks connected to each other by a flow path to have two spaces. The inside of the tank 7 (the above space) may be open to the atmosphere or may be sealed. In the latter case, the pressure inside the tank 7 may be appropriately adjusted by a valve or a vacuum pump or the like. The tank 7 may have a main tank and a sub-tank having a smaller capacity than the main tank. The sub-tank mediates between the main tank and the head 3.

[0025] In the illustrated example, the circulation operation unit 9 includes a pump 15 that sends the liquid from the tank 7 to the head 3, a pressure sensor 17A that detects the pressure of the liquid on the supply port 3b side, and a pressure sensor 17B that detects the pressure of the liquid on the recovery port 3c side. The control unit 11 performs feedback control on the pump 15 so that the pressure difference between the supply port 3b and the recovery port 3c converges to a predetermined target value, for example, based on the detection values of the pressure sensor 17A and the pressure sensor 17B. Thereby, the circulation flow rate is feedback-controlled to the target flow rate.

[0026] Different from the illustrated example, instead of or in addition to the pump 15 on the supply port 3b side, a pump 15 that sends the liquid from the recovery port 3c to the tank 7 may be provided. Further, instead of or in addition to the pump 15 that sends the liquid, the flow of the liquid may be generated by controlling the pressure inside the tank 7 by a vacuum pump or the like. The flow of the liquid may be generated by making the liquid level in the tank containing the supply liquid higher than the liquid level in the tank containing the recovered liquid.

[0027] Instead of, or in addition to, the pressure sensors 17A and 17B, a flow sensor for detecting the flow rate of the liquid supplied to the head 3 and / or a sensor for detecting the flow rate of the liquid recovered from the head 3 may be provided and used for controlling the circulation flow rate. Also, as can be understood from various modes of generating the above liquid flow, instead of, or in addition to, these sensors, a sensor for detecting the air pressure in the tank 7 may be provided and used for controlling the circulation flow rate. Open-loop control may be performed without performing feedback control based on the sensor. That is, the sensor may not be provided.

[0028] The tank 7 and the circulation operation unit 9 are not moved, for example, in the absolute coordinate system by the moving unit 5. Therefore, for example, in the mode where the moving unit 5 moves the head 3 in the absolute coordinate system, the head 3 moves relative to the tank 7 and the circulation operation unit 9. In this case, the head 3 and the tank 7 and the circulation operation unit 9 may be connected by a flow path constituted by, for example, a flexible tube. Also, in the mode where the moving unit 5 does not move the head 3 in the absolute coordinate system, the head 3 is fixed relative to the tank 7 and the circulation operation unit 9. In this case, the configuration of the flow path connecting the head 3 and the tank 7 and the circulation operation unit 9 is arbitrary. Different from the above description, all or part of the tank 7 and the circulation operation unit 9 may move together with the head 3.

[0029] (Control Unit) The control unit 11 is constituted by, for example, a computer. The computer has a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an external storage device, although not particularly shown. By the CPU executing a program stored in the ROM and / or the external storage device, control of the head 3, the moving unit 5, and the circulation operation unit 9 is performed.

[0030] (Head) FIG. 2(a) is an exploded perspective view of the head 3.

[0031] The head 3 includes a flow path member 19 (reference numerals are shown in FIG. 1) having a flow path through which a liquid flows, an actuator 21 that applies pressure to the liquid in the flow path member 19, and a signal transmission member 23 (not shown in FIG. 1) for inputting a drive signal to the actuator 21. The flow path member 19 includes a first flow path member 25 having a discharge surface 3a and a second flow path member 27 having a supply port 3b and a recovery port 3c. The surface of the first flow path member 25 opposite to the discharge surface 3a may be referred to as a pressurized surface 25a.

[0032] The first flow path member 25 and the second flow path member 27 are each configured in a substantially flat plate shape, and by overlapping each other, they form a substantially flat plate-shaped flow path member 19. The liquid supplied to the supply port 3b is supplied from the second flow path member 27 to the first flow path member 25, and ultimately is discharged from the discharge surface 3a. The liquid remaining without being discharged flows from the first flow path member 25 to the second flow path member 27 and is recovered from the recovery port 3c.

[0033] The control unit 11 outputs a control signal based on predetermined data such as image data. The control signal is input, for example, via the signal transmission member 23 to a driver (not shown) mounted on the signal transmission member 23. The driver generates a drive signal having a predetermined waveform based on the input control signal. The drive signal is input to the actuator 21 via the signal transmission member 23. The actuator 21 applies pressure to the liquid in the flow path member 19 with a pressure waveform corresponding to the waveform of the drive signal. Thereby, the liquid in the flow path member 19 is discharged from the discharge surface 3a. Note that the role sharing between the control unit 11 and the driver may be set as appropriate, and the driver may be regarded as a part of the control unit 11.

[0034] (Second Flow Path Member, Supply Reservoir, and Recovery Reservoir) Figure 2(b) is a perspective view of the second flow path member 27. More specifically, this figure shows the second flow path member 27 as viewed from the side of the first flow path member 25, and the upper side of the paper surface of Figure 2(b) corresponds to the lower side of the paper surface of Figures 1 and 2(a). Figure 3(a) is a plane perspective view of the head 3 as viewed from the side opposite to the ejection surface 3a. In this figure, the shape of the second flow path member 27 and the actuator 21 are shown.

[0035] As shown in Figure 2(b), the second flow path member 27 has two grooves (refer to the reference numerals 29 and 31) formed on the surface on the side of the first flow path member 25. These two grooves are blocked by the first flow path member 25 to form the supply reservoir 29 and the recovery reservoir 31 shown in Figures 2(b) and 3(a). The supply reservoir 29 communicates with the supply port 3b and is a flow path for supplying the liquid supplied to the supply port 3b to the flow path of the first flow path member 25. The recovery reservoir 31 communicates with the recovery port 3c and is a flow path for recovering the liquid from the flow path of the first flow path member 25 and guiding the recovered liquid to the recovery port 3c.

[0036] The supply reservoir 29 and the recovery reservoir 31 have, for example, portions (main portions 29a and 31a) that extend linearly along the longitudinal directions (D2 direction and D5 direction) of the head 3. The main portions 29a and 31a have a length that spans, for example, the length in the longitudinal directions (D2 direction and D5 direction) of the arrangement region of a plurality of nozzles (described later, here refer to the arrangement region of the actuator 21 in Figure 3(a)). Also, the main portion 29a and the main portion 31a are located on opposite sides (D3 direction and D6 direction) in the short hand direction of the head 3 with respect to the arrangement region of the plurality of nozzles. In the description of the embodiment, for the sake of convenience, the shape and dimensions of the supply reservoir 29 and the recovery reservoir 31 may be described by focusing only on the main portions 29a and 31a.

[0037] The supply port 3b leads to, for example, one end (the end in the D2 direction) of the supply reservoir 29. The other end (the end in the D5 direction) of the supply reservoir 29 is a dead end (in other words, a cul-de-sac). The liquid in the supply reservoir 29 flows in the direction from the one end to the other end (the D5 direction). The recovery port 3c leads to, for example, one end (the end in the D5 direction) of the recovery reservoir 31. The other end (the end in the D2 direction) of the recovery reservoir 31 is a dead end (in other words, a cul-de-sac). The liquid in the recovery reservoir 31 flows in the direction from the other end to the one end (the D5 direction). In the illustrated example, the direction in which the liquid in the supply reservoir 29 flows and the direction in which the liquid in the recovery reservoir 31 flows are the same as each other. However, they may be opposite to each other.

[0038] The supply reservoir 29 may have only the main part 29a or may have other parts. In the illustrated example, the supply reservoir 29 has a portion (reference numeral omitted) that extends obliquely in the longitudinal direction of the head 3 from the main part 29a to reach the supply port 3b. Similarly, the recovery reservoir 31 may have only the main part 31a or may have other parts. In the illustrated example, the recovery reservoir 31 has a portion (reference numeral omitted) that extends obliquely in the longitudinal direction of the head 3 from the main part 31a to reach the recovery port 3c.

[0039] The shapes and dimensions of the cross-sections of the supply reservoir 29 and the recovery reservoir 31 (for example, the main parts 29a and 31a thereof) may be constant regardless of the positions in the length direction of these flow paths, or may vary depending on the positions. In the description of the embodiment, the former may be taken as an example. Also, the shape of the cross-section may be an appropriate shape such as a rectangle. The various dimensions of the supply reservoir 29 and the recovery reservoir 31 may be appropriately set according to the specific technical field to which the ejection device 1 is applied.

[0040] In the illustrated example, in addition to the two grooves that serve as the supply reservoir 29 and the recovery reservoir 31, the second flow path member 27 has a slit 27a (FIGS. 2(a) and 2(b)) through which the signal transmission member 23 is inserted, and a recess 27b (FIGS. 2(b) and 3(a)) that houses the actuator 21. The slit 27a penetrates the second flow path member 27 from the first flow path member 25 side to the opposite side, for example, and extends along the longitudinal direction of the head 3. The recess 27b has a planar shape that is slightly larger than the actuator 21, for example, and in the illustrated example, is a rectangle having the longitudinal direction of the head 3 as its longitudinal direction.

[0041] The material and the like of the second flow path member 27 are arbitrary. For example, the second flow path member 27 may be made of metal, resin, ceramic, or a combination thereof.

[0042] (First flow path member) FIG. 3(b) is a plan perspective view of the head 3. In this figure, the shape of the first flow path member 25 and the actuator 21 are shown. FIG. 4 is an enlarged view of the region IV in FIG. 3(b).

[0043] The flow path of the first flow path member 25 has a plurality of supply manifolds 33 to which liquid is supplied from the supply reservoir 29, and a plurality of individual flow paths 35 to which liquid is supplied from the supply manifolds 33. The individual flow paths 35 include nozzles (described later) that eject liquid from the ejection surface 3a. The flow path of the first flow path member 25 also has a plurality of recovery manifolds 37 that collect liquid from the plurality of individual flow paths 35 and guide the collected liquid to the recovery reservoir 31.

[0044] Although not particularly shown, the first flow path member 25 may also have a flow path that is located in the D2 direction and the D5 direction with respect to the plurality of supply manifolds 33, the plurality of individual flow paths 35, and the plurality of recovery manifolds 37, and that connects the supply reservoir 29 and the recovery reservoir 31. Such a flow path contributes to, for example, equalizing the temperature of the first flow path member 25.

[0045] (Manifold) The supply manifold 33 has a main portion 33a (which corresponds to substantially the whole of the supply manifold 33 in the illustrated example) that extends linearly along the D4 direction, for example, from the supply reservoir 29 side to the recovery reservoir 31 side. The D4 direction is inclined with respect to the short-side direction (D6 direction) of the head 3. Similarly, the recovery manifold 37 has a main portion 37a (which corresponds to substantially the whole of the recovery manifold 37 in the illustrated example) that extends linearly along the D1 direction, for example, from the recovery reservoir 31 side to the supply reservoir 29 side. The D1 direction is inclined with respect to the short-side direction (D3 direction) of the head 3. In the description of the embodiment, for the sake of convenience, the shape and dimensions of the supply manifold 33 and the recovery manifold 37 may be described by focusing only on the main portions 33a and 37a

[0046] One end (the end in the D1 direction) of the supply manifold 33 overlaps the supply reservoir 29 in a plan view. The said one end communicates with the supply reservoir 29 through an opening 33b that opens on the surface of the first flow path member 25 on the second flow path member 27 side. The other end (the end in the D4 direction) of the supply manifold 33 is a dead end. Therefore, the liquid in the supply reservoir 29 is supplied to the said one end of the supply manifold 33 through the opening 33b and flows in the supply manifold 33 in the direction from the said one end to the said other end (D4 direction).

[0047] One end (the end in the D4 direction) of the recovery manifold 37 overlaps the recovery reservoir 31 in a plan view. The said one end communicates with the recovery reservoir 31 through an opening 37b that opens on the surface of the first flow path member 25 on the second flow path member 27 side. The other end (the end in the D1 direction) of the recovery manifold 37 is a dead end. Therefore, the liquid in the recovery manifold 37 flows in the direction from the said other end to the said one end (D4 direction) and is recovered into the recovery reservoir 31 through the opening 37b.

[0048] The supply manifold 33 and the recovery manifold 37 have lengths extending across the lengths in the short-side directions (D3 direction and D6 direction) of the arrangement regions of a plurality of nozzles (described later, here referring to the arrangement region of the actuator 21). Note that the end portion (the end portion in the D4 direction) of the supply manifold 33 on the recovery reservoir 31 side is, for example, located on the supply reservoir 29 side rather than the recovery reservoir 31. Similarly, the end portion (the end portion in the D1 direction) of the recovery manifold 37 on the supply reservoir 29 side is, for example, located on the recovery reservoir 31 side rather than the supply reservoir 29.

[0049] The plurality of supply manifolds 33, for example, have the same configuration as each other and are arranged at a constant pitch along the D2 direction. In other words, the plurality of supply manifolds 33 extend parallel to each other with the same length. The connection positions (openings 33b) of the plurality of supply manifolds 33 to the supply reservoir 29 are arranged at a constant pitch along the supply reservoir 29.

[0050] Similarly, the plurality of recovery manifolds 37, for example, have the same configuration as each other and are arranged at a constant pitch along the D2 direction. In other words, the plurality of recovery manifolds 37 extend parallel to each other with the same length. The connection positions (openings 37b) of the plurality of recovery manifolds 37 to the recovery reservoir 31 are arranged at a constant pitch along the recovery reservoir 31.

[0051] The plurality of supply manifolds 33 and the plurality of recovery manifolds 37 are, for example, arranged alternately at a constant pitch. Also, the supply manifold 33 and the recovery manifold 37 are adjacent to each other and extend parallel to each other. More specifically, most of the upstream side of the supply manifold 33 and most of the downstream side of the recovery manifold 37 are adjacent to each other in the arrangement region of the plurality of nozzles.

[0052] The cross-sectional shapes and dimensions of the supply manifold 33 and the recovery manifold 37 (for example, their main parts 33a and 37a) may be constant regardless of their longitudinal positions in these flow paths, or may vary depending on the positions. In the description of the embodiments, the former may be taken as an example. Also, the cross-sectional shape may be an appropriate shape such as a rectangle. The various dimensions of the supply manifold 33 and the recovery manifold 37 may be appropriately set according to the specific technical field to which the ejection device 1 is applied.

[0053] (Individual flow path) The individual flow paths 35 are located, for example, generally between the adjacent supply manifold 33 and recovery manifold 37 and are connected to both of them. A plurality of individual flow paths 35 are provided for each set of manifolds (33 and 37). The plurality of individual flow paths 35 connected to the same manifold (33 and 37) are arranged, for example, at a constant pitch along the manifold (along the D1 direction) and constitute a row of flow paths. Then, by arranging a plurality of rows of flow paths in the D2 direction, a plurality of individual flow paths 35 are arranged in a matrix. Different from the illustrated example, two or more rows of individual flow paths 35 may be provided between the adjacent supply manifold 33 and recovery manifold 37.

[0054] Within one row of flow paths, the configurations of the plurality of individual flow paths 35 are basically the same. Also, the configurations of the plurality of rows of flow paths are basically the same. However, for example, the directions of the individual flow paths 35 may be different between adjacent rows of flow paths (illustrated example). Also, for example, within one row of flow paths, the shapes and / or dimensions of the plurality of individual flow paths 35 may slightly differ. Among the plurality of rows of flow paths, the row of flow paths located at the end in the D2 direction and the row of flow paths located at the end in the D5 direction may have so-called dummy individual flow paths that do not eject droplets.

[0055] The individual flow path 35 has a nozzle 43 that opens to the ejection surface 3a and ejects droplets. A row configured by arranging a plurality of nozzles 43 in the D1 direction is referred to as a nozzle row. The arrangement direction (D1 direction) of the nozzles 43 within the nozzle row is inclined with respect to the relative movement direction (D3 direction) of the head 3 with respect to the object 101. Due to the above inclination, the positions of the nozzles 43 belonging to the same nozzle row are different from each other in the D2 direction. Also, a part of the plurality of nozzle rows overlap each other when viewed in the D3 direction. In this overlapping portion, the position of the nozzle 43 of one nozzle row and the position of the nozzle 43 of the other nozzle row are different from each other in the D2 direction. Then, when the plurality of nozzles 43 are projected in the D3 direction, the plurality of nozzles 43 are arranged at substantially constant intervals in the D2 direction.

[0056] As a result, a plurality of dots arranged in the D2 direction at a pitch shorter than the distance between the nozzles 43 adjacent to each other in the head 3 can be formed on the surface of the object 101. For example, 32 nozzles 43 are projected within the range of the virtual straight line R, and the nozzles 43 are arranged at intervals of 360 dpi within the virtual straight line R. As a result, if the object 101 and the head 3 are relatively moved in a direction orthogonal to the virtual straight line R to eject droplets, printing can be performed at a resolution of 360 dpi.

[0057] FIG. 5 is a perspective view of the individual flow path 35. FIGS. 6(a) and 6(b) are cross-sectional views of the first flow path member 25 and the actuator 21. FIG. 6(a) corresponds to the line VIa-VIa in FIG. 5. FIG. 6(b) corresponds to the line VIb-VIb in FIG. 5.

[0058] The individual flow path 35 has, for example, a supply flow path 39 (a first supply flow path 39A and a second supply flow path 39B) connected to the supply manifold 33, a pressure chamber 41 connected to the supply flow path 39, and a nozzle 43 connected to the pressure chamber 41. As described above, the nozzle 43 opens to the ejection surface 3a and communicates with the outside of the first flow path member 25. The liquid in the supply manifold 33 is supplied to the nozzle 43 via the supply flow path 39 and the pressure chamber 41. Then, when pressure is applied to the pressure chamber 41 by the actuator 21, droplets are ejected from the nozzle 43. Further, the individual flow path 35 has a recovery flow path 45 connecting the pressure chamber 41 and the recovery manifold 37. The liquid remaining in the pressure chamber 41 without being ejected is recovered from the recovery flow path 45 to the recovery manifold 37.

[0059] The pressure chamber 41 has, for example, a pressure chamber main body 41a to which pressure is applied by the actuator 21, and a descender 41b connecting the pressure chamber main body 41a and the nozzle 43.

[0060] The pressure chamber main body 41a opens, for example, to the pressurized surface 25a of the first flow path member 25 and is blocked by the actuator 21. Then, when the actuator 21 bends and deforms upward and / or downward, pressure is applied to the liquid in the pressure chamber main body 41a. The descender 41b extends from the lower surface of the pressure chamber main body 41a toward the ejection surface 3a. The cross-sectional area of the descender 41b is smaller than the cross-sectional area of the cross section parallel to the pressurized surface 25a of the pressure chamber main body 41a.

[0061] The shape and dimensions of the pressure chamber main body 41a may be set as appropriate. In the illustrated example, the planar shape of the pressure chamber main body 41a is circular. Different from the illustrated example, the planar shape of the pressure chamber main body 41a may be a shape other than a circle, such as an ellipse or a rhombus, for example. Further, the pressure chamber main body 41a has a thin shape with a thickness smaller than the diameter in a plan view. In the illustrated example, the shape and dimensions of the cross section parallel to the pressurized surface 25a of the pressure chamber main body 41a are constant in the vertical direction. However, the cross-sectional shape and / or its dimensions of the pressure chamber main body 41a may be different depending on the vertical position.

[0062] The shape and dimensions of the descender 41b may also be set as appropriate. In the illustrated example, the shape of the descender 41b is a straight column. Also, in the illustrated example, the shape of the cross-section is circular. Different from the illustrated example, the descender 41b may be inclined with respect to the vertical direction, or the diameter may change according to the vertical position. Also, the shape of the cross-section may be a shape other than a circle such as an ellipse.

[0063] The connection position of the descender 41b to the pressure chamber body 41a in plan view may also be set as appropriate. In the illustrated example, the descender 41b is connected adjacent to the outer edge of the circular pressure chamber body 41a. Different from the illustrated example, in the case where the shape of the pressure chamber body 41a is an ellipse or a rhombus, for example, the descender 41b may be connected to the longitudinal end of the pressure chamber body 41a.

[0064] The nozzle 43 opens at a part of the bottom surface of the descender 41b. The nozzle 43 may, for example, open at the center of the bottom surface of the descender 41b, or may open at a position away from the center (illustrated example). The shape of the longitudinal cross-section of the nozzle 43 is tapered so that the diameter becomes smaller toward the discharge surface 3a side. However, a part or all of the nozzle 43 may be an inverse taper. The shape of the cross-section of the nozzle 43 is, for example, circular.

[0065] The supply flow path 39 has, for example, a first supply flow path 39A and a second supply flow path 39B. Different from the illustrated example, the supply flow path 39 may have only one of the first supply flow path 39A and the second supply flow path 39B. In the supply flow path 39, the connection position to the supply manifold 33, the connection position to the pressure chamber 41, the flow path shape, and the dimensions may be set as appropriate. In the illustrated example, it is as follows.

[0066] The first supply channel 39A connects the supply manifold 33 and the pressure chamber body 41a. The first supply channel 39A extends upward from the upper surface of the supply manifold 33, then extends in the D5 direction, extends in the D4 direction, and then extends upward again and is connected to the lower surface of the pressure chamber body 41a. The shape and dimensions of the cross-section of the first supply channel 39A are substantially constant over most (e.g., 60% or more) of the length of the first supply channel 39A. The shape of the cross-section over this majority is rectangular.

[0067] The second supply channel 39B connects the supply manifold 33 and the descender 41b. The second supply channel 39B extends in the D5 direction from the lower surface of the supply manifold 33, extends in the D1 direction, and is then connected to the side surface of the descender 41b. The shape and dimensions of the cross-section of the second supply channel 39B are substantially constant over most (e.g., 60% or more) of the length of the second supply channel 39B. The shape of the cross-section over this majority is rectangular.

[0068] The recovery channel 45 is provided, for example, only one in each individual channel 35. Different from the illustrated example, two or more recovery channels 45 may be provided. In the recovery channel 45, the connection position to the recovery manifold 37, the connection position to the pressure chamber 41, the channel shape and dimensions may be set as appropriate. In the illustrated example, it is as follows.

[0069] The recovery channel 45 connects the recovery manifold 37 and the descender 41b. The recovery channel 45 extends in the D2 direction from the side surface of the recovery manifold 37, extends in the D4 direction, and is then connected to the side surface of the descender 41b. The shape and dimensions of the cross-section of the recovery channel 45 are substantially constant over most (e.g., 60% or more) of the length of the recovery channel 45. The shape of the cross-section over this majority is rectangular.

[0070] As described above, the plurality of individual flow paths 35 connected to the same supply manifold 33 and the same recovery manifold 37 are arranged at a constant pitch along the manifold. Therefore, the connection positions of the first supply flow path 39A and the supply manifold 33 are aligned at a constant pitch along the supply manifold 33. The same applies to the connection position of the second supply flow path 39B and the supply manifold 33, and the connection position of the recovery flow path 45 and the recovery manifold 37.

[0071] As shown in FIGS. 6(a) and 6(b), the first flow path member 25 is formed by laminating a plurality of plates 47A to 47M. The various flow paths of the first flow path member 25 are constituted by holes or recesses formed in the plates 47A to 47M. The plurality of plates 47A to 47M may be formed of, for example, metal or resin. In the example shown in FIG. 6(b), dampers (reference numerals omitted) are provided above and below the recovery manifold 37.

[0072] As described above, the pressure chamber 41 opens to the pressurizing surface 25a. Different from the illustrated example, a plate for closing the pressure chamber 41 may be provided. However, in this case, it can also be considered as a problem of whether to regard the plate for closing the pressure chamber 41 as a part of the first flow path member 25 or as a part of the actuator 21. In the description of the present disclosure, the above-described plate shall be regarded as a part of the actuator 21.

[0073] (Actuator) As shown in FIG. 2(a), the actuator 21 is, for example, a substantially flat plate-like member and is joined to the pressurizing surface 25a of the first flow path member 25 (more specifically, the region indicated by the dotted line in FIG. 2(a)). Then, as shown in FIGS. 6(a) and 6(b), the actuator 21 closes the opening above the pressure chamber 41. The actuator 21 basically extends over the arrangement regions of all the pressure chambers 41. The actuator 21 has a displacement element 49 for each pressure chamber 41.

[0074] The configuration of the actuator 21 may be various known configurations or those applying known configurations. In the illustrated example, the actuator 21 is a so-called unimorph type piezoelectric actuator. Specifically, it is as follows.

[0075] The actuator 21 has a diaphragm 51, a common electrode 53, a piezoelectric layer 55, and an individual electrode 57, which are laminated in order from the pressure chamber 41 side. The diaphragm 51, the common electrode 53, and the piezoelectric layer 55 basically extend over the arrangement regions of all the pressure chambers 41. The individual electrode 57 is provided for each pressure chamber 41. The individual electrode 57 has, for example, a shape similar to the planar shape of the pressure chamber 41 in a planar perspective view, and also overlaps the central side of the pressure chamber 41.

[0076] The portion of the piezoelectric layer 55 sandwiched between the individual electrode 57 and the common electrode 53 is polarized in the thickness direction. Therefore, when a voltage is applied to the individual electrode 57 and the common electrode 53, the piezoelectric layer 55 contracts or expands in the direction along the surface. This contraction or expansion is restricted by the diaphragm 51, and the displacement element 49 bends toward the pressure chamber 41 side or the opposite side like a bimetal. Thereby, pressure is applied to the liquid in the pressure chamber 41.

[0077] The materials, thickness, etc. of each layer of the actuator 21 may be set as appropriate. For example, the diaphragm 51 and the piezoelectric layer 55 may be made of ceramic materials such as lead zirconate titanate (PZT) - based, NaNbO3 - based, BaTiO3 - based, (BiNa)NbO3 - based, BiNaNb5O 15 - based systems. The common electrode 53 and the individual electrode 57 may be made of metal materials such as Ag - Pd - based or Au - based.

[0078] A certain potential (reference potential) is applied to the common electrode 53, for example. The drive signal as described above is input to the individual electrode 57, for example. The drive method of the displacement element 49 (the waveform of the drive signal from another perspective) may be appropriate. For example, the drive method may be a so - called impact type.

[0079] (Liquid) Figure 7 is a diagram showing the characteristics of the liquid used in the ejection device 1. In this figure, the horizontal axis represents the shear rate D (1 / s), and the vertical axis represents the viscosity η (Pa·s). EX1 and EX2 show the characteristics of the first and second examples of the liquid used in the ejection device 1.

[0080] As shown in this figure, the liquid used in the ejection device 1 is a pseudoplastic fluid. To describe it confirmatively, a pseudoplastic fluid can be said to be a non-Newtonian fluid whose viscosity decreases as the shear rate increases. The shear rate is sometimes also referred to as the slip rate, velocity gradient, or strain rate. The shear rate can be calculated, for example, simply as the value obtained by dividing the velocity difference between two positions separated from each other in a direction perpendicular to the flow direction by the distance between the two positions. The viscosity can be calculated, for example, simply as the value obtained by dividing the shear stress by the shear rate. The shear stress is sometimes also referred to as the slip stress. The shear stress can be calculated, for example, simply as the value obtained by dividing the force that tries to shift two parallel surfaces (of the same area) separated from each other in a direction perpendicular to the flow direction in the flow direction by the area of one of the surfaces.

[0081] Also, a pseudoplastic fluid can be said to be a power-law fluid in which the power exponent p is less than 1 when the viscosity η is approximated by the power-law of η = k × D p-1 Here, k is the viscosity coefficient and D is the shear rate. Since the viscosity η is a function of D, it is sometimes also referred to as the apparent viscosity.

[0082] The liquid used in the ejection device 1 may or may not have thixotropy in which the viscosity decreases as the time of receiving the shear stress increases.

[0083] Specific components and / or compositions of the pseudoplastic fluid may be various known ones or those applying known ones. For example, generally, ink and paint are pseudoplastic fluids. The liquids according to the first and second examples whose characteristics are shown in FIG. 7 are general paints (in other words, paints available on the market). Specific characteristics of the pseudoplastic fluid may also be appropriate ones. One example is given below.

[0084] For example, the liquid may have a viscosity of 0.02 Pa·s or more and 0.4 Pa·s or less when the shear rate is 1000 s -1 . In the paint according to the first example whose characteristics are shown in FIG. 7, the viscosity is 0.3 Pa·s when the shear rate is 1000 s -1 . In the paint according to the second example, the viscosity is 0.1 Pa·s when the shear rate is 1000 s -1 . The liquid may have a viscosity of 0.1 Pa·s or more and 0.3 Pa·s or less when the shear rate is 1000 s -1 .

[0085] Also, for example, the liquid may have a viscosity of 0.5 Pa·s or more and 50 Pa·s or less when the shear rate is 0.01 s -1 . In the paint according to the first example whose characteristics are shown in FIG. 7, the viscosity is 5 Pa·s when the shear rate is 0.01 s -1 . In the paint according to the second example, the viscosity is 30 Pa·s when the shear rate is 0.01 s -1 . The liquid may have a viscosity of 5 Pa·s or more and 30 Pa·s or less when the shear rate is 0.01 s -1 .

[0086] Also, for example, when the viscosity of the liquid is approximated by the power law, the viscous coefficient k may be 1.0 or more and 1.5 or less, and the power exponent p may be 0.35 or more and 0.65 or less. In the paint according to the first example, the viscous coefficient k is 1.0 and the power exponent p is 0.65. In the paint according to the second example, the viscous coefficient k is 1.5 and the power exponent p is 0.35. The approximation formula may be specified, for example, by the least squares method.

[0087] (Average Viscosity) Hereinafter, the concept of average viscosity is introduced. Originally, the viscosity shows different values for each minute area in the flow path. However, the viscosity for each minute area is not necessarily suitable for setting the viscosity of the liquid in the flow path member 19, and its calculation may also be difficult. Therefore, the viscosity averaged for each part of the flow path of the flow path member 19 is defined as the average viscosity. The average viscosity is one value for one part in the flow path. For example, when referring to the average viscosity of one supply manifold 33, it is the average viscosity throughout the entire supply manifold 33.

[0088] The average viscosity may be calculated, for example, as follows. First, the relationship between the shear rate D and the viscosity η in the liquid used in the discharge device 1 is specified. In this specification, various known methods may be adopted, or it may be specified by referring to known literature. Next, an approximate formula representing the relationship between the specified shear rate D and viscosity η is obtained. The approximate formula may be an appropriate one such as the power law, etc. The fitting method may also be a known one such as the least squares method. Next, with the circulation flow rate U (m 3 / s) as the boundary condition, fluid simulation is performed for each part of the flow path using the above approximate formula, and the differential pressure ΔP (Pa) between the upstream end and the downstream end of each part is obtained. Then, the average viscosity μ (Pa·s) is calculated by substituting the circulation flow rate U, the differential pressure ΔP, and the dimensions (m) of each part into a predetermined formula.

[0089] An example of the formula for calculating the average viscosity μ is shown below.

[0090] The formula in the case where the flow path shape is cylindrical with the flow direction as the axial direction is as follows. U=(πr 4 ΔP) / (8μL) (1) Here, r is the radius of the cross section. L is the length of the flow path.

[0091] Also, the formula in the case where the flow path shape is prismatic (cuboid) with the flow direction as the axial direction is as follows. U=(w 3(hΔP) / (4μL) ×(16 / 3 - 1024 / π 5 ×w / h ×Σ(1 / q 5 ×tanh(qπh / 2w)) (2) Here, q = 1, 3, 5, 7, 9, and 11, and Σ is the sum of six (1 / q 5 ×tanh(qπh / 2w)) when these six values are substituted for q. w is the width of the flow path. h is the height of the flow path. L is the length of the flow path.

[0092] In the reservoirs (29 and 31) and the manifolds (33 and 37), the flow rate U is different between the upstream side and the downstream side. In this case, for example, any of the maximum flow rate, the minimum flow rate, or the average flow rate may be used. The average viscosity in the following description may be regarded as being calculated using any of the above flow rates. When comparing the average viscosity of the reservoirs (29 and 31) and the average viscosity of the manifolds (33 and 37), the average viscosities calculated under the same conditions for each other may be compared. For example, the average viscosities calculated using the maximum flow rate (the lowest average viscosity) may be compared, the average viscosities calculated using the minimum flow rate (the highest average viscosity) may be compared, or the average viscosities calculated using the average flow rate (the average average viscosity) may be compared. For example, the average viscosity in the following description may be regarded as the average viscosity calculated using the maximum flow rate (the lowest average viscosity). For example, the average viscosities of the supply reservoir 29 and the supply manifold 33 may be regarded as being calculated using the most upstream flow rate. The average viscosities of the recovery reservoir 31 and the recovery manifold 37 may be regarded as being calculated using the most downstream flow rate.

[0093] In the pressure chamber 41, or the pressure chamber main body 41a or the descender 41b, the direction of the liquid flow is not always constant. The average viscosity at these parts in the following description is assumed to be calculated with the direction from above to below as the flow direction. For example, the average viscosity in the descender 41b is assumed to be calculated with the direction from the pressure chamber main body 41a to the nozzle 43 as the flow direction.

[0094] (Average viscosity in the flow path member) FIG. 8 is a diagram showing an example of the relative relationship between parts of the flow path in the flow path member 19 with respect to the average viscosity μ for each part of the flow path. In this figure, the horizontal axis corresponds to a plurality of parts of the flow path of the flow path member 19. The vertical axis indicates the average viscosity μ at each part.

[0095] Note that in the figure, the average viscosity μ2 indicates the average viscosity μ in one supply manifold 33 out of the plurality of supply manifolds 33. Similarly for other flow paths, the average viscosity μ in one flow path is shown. The average viscosity μ3 of the supply flow path 39 may be regarded as the average viscosity of either the first supply flow path 39A or the second supply flow path 39B.

[0096] The liquid discharge device 1 is controlled by the flow rate setting unit 13 such that the relationship of the average viscosity as shown in the figure is satisfied, and the target flow rate of the circulation flow rate and the shape and dimensions of the flow path of the flow path member 19 are set. In other words, the flow path of the flow path member 19 has a flow path shape in which the relationship shown in FIG. 8 holds when the circulation flow rate is the target flow rate. In other words, the circulation flow rate is set to a value such that the relationship of the average viscosity shown in FIG. 8 holds in the shape and dimensions of the flow path of the flow path member 19. For example, in the shape and dimensions of the flow path of the flow path member 19, the circulation flow rate is set to a value such that the average viscosity of the liquid in the supply flow path 39 is half or less of the average viscosity of the liquid in the supply manifold 33.

[0097] When the adjustment of the circulation flow rate is open-loop control, the variation amount of the circulation flow rate due to the discharge amount of droplets from the plurality of nozzles 43 is large. In this case, the relationship shown in FIG. 8 may hold, for example, at the circulation flow rate when droplets are not being discharged from all the nozzles 43. In other words, in the implemented product, the circulation flow rate when droplets are not being discharged from all the nozzles 43 may be specified as the target flow rate in that product. This concept may also be applied to feedback control with low followability of the circulation flow rate to the target flow rate.

[0098] In FIG. 8, for example, the following relationship holds for the average viscosity.

[0099] The average viscosity μ3 of the liquid in the supply channel 39 (39A or 39B) may be made lower than the average viscosity μ2 of the liquid in the supply manifold 33. More specifically, for example, the average viscosity μ3 may be made 1 / 2 or less, 1 / 3 or less, or 1 / 5 or less of the average viscosity μ2.

[0100] In this case, for example, since the average viscosity μ3 of the liquid in the supply channel 39 is low, the liquid can be smoothly supplied from the supply channel 39 to the pressure chamber 41. Also, since the average viscosity μ2 is high in the supply manifold 33, the pressure wave is likely to attenuate. As a result, the probability that the pressure wave leaking from the pressure chamber 41 to the supply manifold 33 via the supply channel 39 propagates to another pressure chamber 41 via another supply channel 39 is reduced. That is, so-called fluid crosstalk can be reduced.

[0101] A relationship similar to the above may also hold between the recovery channel 45 and the recovery manifold 37. That is, the average viscosity μ5 of the liquid in the recovery channel 45 may be made lower than the average viscosity μ6 of the liquid in the recovery manifold 37. More specifically, for example, the average viscosity μ5 may be made 1 / 2 or less, 1 / 3 or less, or 1 / 5 or less of the average viscosity μ6. In this case as well, the same effect as above is achieved.

[0102] The average viscosity μ2 of the supply manifold 33 may be made lower than the average viscosity μ1 of the supply reservoir 29. More specifically, for example, the average viscosity μ2 may be made 1 / 2 or less, 1 / 3 or less, or 1 / 4 or less of the average viscosity μ1.

[0103] In this case, for example, since the average viscosity μ2 of the liquid in the supply manifold 33 is low, the liquid can be smoothly supplied from the supply manifold 33 to the supply channel 39. Also, since the viscosity is high in the supply reservoir 29 and the pressure wave is likely to attenuate, crosstalk due to the propagation of the pressure wave via the supply reservoir 29 can be reduced.

[0104] A similar relationship may also hold between the recovery manifold 37 and the recovery reservoir 31. That is, the average viscosity μ6 of the liquid in the recovery manifold 37 may be made lower than the average viscosity μ7 of the liquid in the recovery reservoir 31. More specifically, for example, the average viscosity μ6 may be made 1 / 2 or less, 1 / 3 or less, or 1 / 5 or less of the average viscosity μ7. In this case as well, the same effects as described above are achieved.

[0105] The average viscosity μ4 of the descender 41b may be made higher than the average viscosity μ5 of the recovery flow path 45. More specifically, for example, the average viscosity μ4 may be made 1.5 times or more that of the average viscosity μ5.

[0106] In this case, for example, since the resistance to the movement of air bubbles increases when the viscosity is high, the probability of recovering the air bubbles that have entered the descender 41b from the nozzle 43 through the recovery flow path 45 is increased.

[0107] A similar relationship may also hold between the descender 41b and the supply flow path 39. That is, the average viscosity μ4 of the descender 41b may be made higher than the average viscosity μ3 of the supply flow path 39. More specifically, for example, the average viscosity μ4 may be made 1.5 times or more, or 2 times or more that of the average viscosity μ3.

[0108] In this case, for example, since the average viscosity μ3 of the supply flow path 39 is low, the liquid can be smoothly supplied to the descender 41b. As a result, for example, the probability that the liquid supply to the descender 41b will be insufficient due to the continuous discharge of the liquid is reduced.

[0109] The average viscosity μ2 of the supply manifold 33 may be made higher than the average viscosities (μ3, μ4, and μ5) of the respective flow paths of the individual flow paths 35 (excluding the pressure chamber main body 41a). More specifically, for example, the average viscosity μ2 may be made 1.5 times or more with respect to any of the average viscosities μ3, μ4, and μ5.

[0110] In this case, for example, since the average viscosity μ in the individual flow path 35 is low, the liquid can be smoothly supplied to the nozzle 43. Further, since the average viscosity μ in the supply manifold 33 is high, the pressure that has leaked from the individual flow path 35 to the supply manifold 33 quickly decays. Therefore, fluid crosstalk is less likely to occur.

[0111] A similar relationship may hold between the recovery manifold 37 and the individual flow path 35. That is, the average viscosity μ6 of the liquid in the recovery manifold 37 may be made higher than the average viscosities (μ3, μ4, and μ5) of the respective flow paths of the individual flow path 35. More specifically, for example, the average viscosity μ6 may be set to 1.5 times or more that of any of the average viscosities μ3, μ4, and μ5. In this case as well, the same effect as described above is achieved.

[0112] (An example of values such as average viscosity) There are innumerable combinations of the characteristics of the liquid, the circulation flow rate, the shape and dimensions of the flow path, etc. that realize the relationship of the average viscosity μ as described above, and they may be appropriately set according to the specific technical field to which the discharge device 1 is applied. Hereinafter, an example of values when a general paint described with reference to FIG. 7 is used is shown.

[0113] The circulation flow rate may be, for example, 50 ml / min or more and 300 ml / min or less. The pressure at the nozzle 43 when the liquid is not being discharged may be ±2 kPa with respect to the atmospheric pressure (about 100 kPa). The differential pressure between the supply port 3b and the recovery port 3c may be 40 kPa or more and 160 kPa or less.

[0114] In each of the supply reservoir 29 and the recovery reservoir 31, the width w may be 4 mm or more and 20 mm or less, the height h may be 3 mm or more and 15 mm or less, and the length L may be 200 mm or more and 800 mm or less. In each of the supply manifold 33 and the recovery manifold 37, the width w may be 0.2 mm or more and 2 mm or less, the height h may be 0.5 mm or more and 6 mm or less, and the length L may be 5 mm or more and 20 mm or less. In the first supply channel 39A, each of the width w and the height h may be 50 μm or more and 200 μm or less. In the second supply channel 39B, the width w may be 50 μm or more and 200 μm or less, and the height h may be 25 μm or more and 200 μm or less. In the recovery channel 45, the width w may be 70 μm or more and 200 μm or less, and the height h may be 80 μm or more and 200 μm or less. The lengths L of the supply channel 39 and the recovery channel 45 may be 300 μm or more and 1500 μm or less. In the descender 41b, the radius r may be 50 μm or more and 250 μm or less, and the length L may be 0.5 mm or more and 2 mm or less. In the nozzle 43, the radius r may be 5 μm or more and 50 μm or less.

[0115] An example of the estimation of the average viscosity μ under the above conditions is shown below. The average viscosity μ of the descender 41b was calculated by equation (1), and for the other channels, the average viscosity μ was calculated by equation (2). The average viscosity μ in each of the supply reservoir 29 and the recovery reservoir 31 is 0.4 Pa·s or more and 2 Pa·s or less. The average viscosity μ in each of the supply manifold 33 and the recovery manifold 37 is 0.1 Pa·s or more and 0.4 Pa·s or less. The average viscosity μ in each of the supply channel 39 and the recovery channel 45 is 0.01 Pa·s or more and 0.1 Pa·s or less. The average viscosity μ in the descender 41b is 0.05 Pa·s or more and 0.2 Pa·s or less.

[0116] (Fluid resistance) The fluid resistance (N·s / m 5 ) in the channel member 19 may be set as appropriate. For example, the fluid resistance may be set so that both of the following conditions 1 and 2 are satisfied.

[0117] Condition 1: (1 / 2)×R r ×U(1 + 1 / m) and, (1 / 2)×R m ×(U / m)×(1 + 1 / n) is less than 2σ / r. Condition 2: R r <1 / 10×R m ×(1 / m) Here, R r is the fluid resistance of the liquid in the supply reservoir 29. R m is the fluid resistance of the liquid in the supply manifold 33. m is the number of supply manifolds 33 connected to the supply reservoir 29. n is the number of individual flow paths 35 (nozzles 43) for each supply manifold 33. U is the flow rate of the liquid flowing into the supply reservoir 29 (m 3 / s). σ is the surface tension of the liquid (N / m). r is the radius of the nozzle 43 (m).

[0118] Here, the supply manifold 33 to which only the dummy individual flow paths that cannot eject droplets are connected is ignored. Also, it is assumed that the supply manifolds 33 have the same number of nozzles 43 connected to each other. Further, it is assumed that the pitch of the plurality of supply manifolds 33, the distance from the upstream end of the supply reservoir 29 to the first supply manifold 33, and the distance from the last supply manifold 33 to the downstream end of the supply reservoir 29 are equal.

[0119] (1 / 2)×R in Condition 1 r ×U(1 + 1 / m) corresponds to the pressure drop amount (pressure difference between upstream and downstream) in the supply reservoir 29. Specifically, the pressure drop amount from the upstream end of the supply reservoir 29 to the first supply manifold 33 is U×R r / m, and the pressure drop amount from the first supply manifold 33 to the second supply manifold is calculated as (U - U / m)×R r / m. And the total pressure drop amount from the upstream end to the downstream end, U×R r / m + (U - U / m) × R r / m + … + U / m × / R r By / m, the above (1 / 2) × R r × U(1 + 1 / m) is obtained.

[0120] (1 / 2) × R under Condition 1 m × (U / m) × (1 + 1 / n) corresponds to the pressure drop (pressure difference between upstream and downstream) in one supply manifold 33. This formula is obtained in the same way as the pressure drop in the above supply reservoir 29. That is, in the formula related to the supply reservoir 29, the fluid resistance R r of the supply reservoir 29 m is replaced with the fluid resistance R of the supply manifold 33, the flow rate U flowing into the supply reservoir 29 is replaced with the flow rate U / m of the liquid flowing into the supply manifold 33, and the number m of the supply manifolds 33 is replaced with the number n of the nozzles 43.

[0121] (1 / 2) × R under Condition 1 r × U(1 + 1 / m) and (1 / 2) × R m × (U / m) × (1 + 1 / n) is approximately equivalent to the pressure difference between the most upstream individual flow path 35 and the most downstream individual flow path 35. The most upstream individual flow path 35 is the individual flow path 35 connected to the most upstream of the supply manifold 33 connected to the most upstream of the supply reservoir 29. The most downstream individual flow path 35 is the individual flow path 35 connected to the most downstream of the supply manifold 33 connected to the most downstream of the supply reservoir 29. Since the pressure drop of the individual flow paths 35 is approximately equal among the plurality of individual flow paths 35, the above sum corresponds to the pressure difference of all the nozzles 43 (the pressure difference between the nozzle 43 with the highest pressure and the nozzle 43 with the lowest pressure).

[0122] And when the above sum is smaller than 2σ / r, it is easy to hold the meniscus under atmospheric pressure in all the nozzles 43. Regarding Condition 1, as already mentioned, the supply manifold 33 to which only the dummy individual flow paths are connected and the dummy individual flow paths may be ignored. Also, in the most upstream supply manifold 33 or the most downstream supply manifold 33, etc., the number of individual flow paths 35 connected may be less than that of other supply manifolds 33. In this case, for example, the most upstream supply manifold 33 or the most downstream supply manifold 33 may be ignored, or conversely, it may be assumed that the same number of individual flow paths 35 as those of other supply manifolds 33 are also connected to the most upstream supply manifold 33 or the most downstream supply manifold 33.

[0123] Condition 2 shows the magnitude relationship between the fluid resistance R of the supply reservoir 29 r and the fluid resistance R of the supply manifold 33 m Since the flow rate of the liquid flowing into the supply manifold 33 is 1 / m of the flow rate of the liquid flowing into the supply reservoir 29, the fluid resistance R m is multiplied by 1 / m, and the fluid resistance R r is compared with the fluid resistance R m And the fact that Condition 2 is satisfied means that the fluid resistance R of the supply reservoir 29 r is extremely small in comparison with the fluid resistance R of the supply manifold 33 m

[0124] For example, in the prior art, R r is about 1 / 5 of R m ×(1 / m). On the other hand, in the present embodiment, R r may be set to be not less than 1 / 40 and less than 1 / 10 of R m ×(1 / m). Of course, also in the present embodiment, similar to the prior art, R r may be set to be about 1 / 5 of R m ×(1 / m).

[0125] When Condition 2 is satisfied, for example, liquid can flow more easily from the supply reservoir 29 to the positions of the plurality of supply manifolds 33, and the difference in the flow rates between the plurality of supply manifolds 33 is alleviated. As a result, liquid can be stably supplied to all the supply manifolds 33.

[0126] In addition to Conditions 1 and 2, the fluid resistance may be set so that the following Condition 3 is satisfied. Condition 3: R m <1 / 10×R n ×(1 / n) Here, R n is the fluid resistance in the nozzle 43.

[0127] Condition 3 shows the magnitude relationship between the fluid resistance R m of the supply manifold 33 and the fluid resistance of the individual flow path 35. However, since the fluid resistance R n of the nozzle 43 is much larger than the fluid resistance of other parts of the individual flow path 35, the fluid resistance of the individual flow path 35 is approximated by the fluid resistance R n of the nozzle 43. Also, since the flow rate of the liquid flowing into the individual flow path 35 is 1 / n of the flow rate of the liquid flowing into the supply manifold 33, 1 / n is multiplied by the fluid resistance R n to compare the fluid resistance R m with the fluid resistance R n .

[0128] That Condition 3 is satisfied means that the fluid resistance R m of the supply manifold 33 is extremely small in comparison with the fluid resistance R n of the nozzle 43. For example, in the prior art, R m is about 1 / 6 of R n ×(1 / n). In this embodiment as well, similar to the prior art, R m may be about 1 / 6 of R n ×(1 / n). For example, R m may be 1 / 10 or more and 1 / 4 or less of R n ×(1 / n).

[0129] When Condition 3 is satisfied, for example, liquid can flow more easily from the supply manifold 33 to the positions of the plurality of individual flow paths 35, and the difference in the flow rates between the plurality of individual flow paths 35 is alleviated. As a result, liquid can be stably supplied to all the individual flow paths 35.

[0130] Note that an example of the dimensions of the flow path etc. exemplified as an example of the dimensions for realizing the average viscosity shown in FIG. 8 may be referred to as an example of the dimensions of the flow path etc. where Conditions 1 to 3 are satisfied.

[0131] (Modification example) FIG. 9 is a schematic cross-sectional view of the individual flow path 235 according to the modification example.

[0132] The pressure chamber 241 of the individual flow path 235 has a pressure chamber main body 241a and a descender 241b, similar to the pressure chamber 41 of the embodiment. However, the descender 241b has a first part 241ba and a second part 241bb whose cross-sectional areas are different from each other.

[0133] The first part 241ba is connected to the nozzle 43. The second part 241bb is connected to the pressure chamber main body 241a. In other words, the second part 241bb is a part located closer to the pressure chamber main body 241a than the first part 241ba. And the cross-sectional area of the second part 241bb is wider than that of the first part 241ba.

[0134] Since the cross-sectional areas of the first part 241ba and the second part 241bb are different from each other, the average viscosities are different from each other. For example, the average viscosity of the liquid in the second part 241bb is higher than the average viscosity of the liquid in the first part 241ba. In other words, the average viscosity in the descender 241b increases stepwise as it approaches the pressure chamber main body 41a from the nozzle 43. Note that the increase in the average viscosity may increase not only in one step but also in two or more steps. In other words, the descender may have a third part etc. in addition to the first part and the second part.

[0135] When the average viscosity of the second part 241bb located closer to the pressure chamber main body 241a than the first part 241ba is higher than the average viscosity of the first part 241ba as in this modification example, for example, bubbles that have entered the descender 241b from the nozzle 43 are less likely to move toward the pressure chamber main body 241a. As a result, the probability that bubbles stay in the pressure chamber main body 241a and the discharge characteristics deteriorate is reduced.

[0136] In addition, when there are portions with different shapes in at least one of the two flow paths whose average viscosities are compared, the average viscosities of the portions where the two flow paths are in contact with each other may be compared. For example, in the individual flow path 235 according to the modification example, when comparing the average viscosity of the recovery flow path 45 and the average viscosity of the descender 241b, instead of the average viscosity of the entire descender 241b, the average viscosity of the second part 241bb directly connected to the recovery flow path 45 may be used for the comparison. This is because the average viscosity of the second part 241bb has a great influence on the flow between the recovery flow path 45 and the descender 241b.

[0137] The technology according to the present disclosure is not limited to the above-described embodiments and modification examples, and may be implemented in various modes.

[0138] For example, the liquid ejection device is not limited to a piezoelectric type that applies pressure to the liquid by a piezoelectric body. The liquid ejection device may be a thermal type that generates bubbles in the liquid by heat and applies the pressure accompanying the generation of these bubbles to the liquid to eject droplets.

[0139] The configuration of the flow path may be various configurations other than those shown in the drawings. For example, a part of the individual flow paths adjacent to each other may be shared. For example, a part of the recovery manifold side of the recovery flow path may be shared between the individual flow paths adjacent to each other.

[0140] The setting of the average viscosity may also be other than the embodiments. For example, the average viscosity μ3 of the supply flow path 39 may be made larger than the average viscosity μ5 of the recovery flow path 45 or 1.5 times thereof, contrary to the embodiments. In this case, when the liquid droplets are discharged, the liquid in the descender 41b is less likely to flow backward (less likely to flow in the direction opposite to the direction of circulation). Also, the liquid and / or bubbles flow easily through the recovery flow path.

Explanation of Reference Numerals

[0141] 1... Liquid ejection device, 3... Head, 13... Flow rate setting unit, 19... Flow path member, 21... Actuator, 29... Supply reservoir, 31... Recovery reservoir, 33... Supply manifold, 37... Recovery manifold, 39... Supply flow path, 41... Pressure chamber, 43... Nozzle, 45... Recovery flow path.

Claims

1. including a flow path configured such that a predetermined liquid having pseudoplasticity flows therethrough, said flow path comprising: a supply reservoir; a plurality of supply manifolds connected to said supply reservoir; a flow path member having a plurality of pressure chambers connected one-to-one to a plurality of supply flow paths; an actuator configured to apply pressure to the liquid in said plurality of pressure chambers and eject droplets from a plurality of nozzles connected one-to-one to said plurality of pressure chambers; a pump configured such that the liquid flows through said supply reservoir, said plurality of supply manifolds, said plurality of supply flow paths, and said plurality of pressure chambers in sequence; a controller configured to adjust the flow rate of said liquid to a predetermined target flow rate; wherein said flow path has a flow path shape such that when said flow rate is said target flow rate, an average viscosity of said liquid in said supply flow path is equal to or less than half of an average viscosity of said liquid in said supply manifold. Device.

2. wherein said flow path has a flow path shape such that when said flow rate is said target flow rate, an average viscosity of said liquid in said supply manifold is equal to or less than half of an average viscosity of said liquid in said supply reservoir. The device according to claim 1.

3. a plurality of recovery flow paths separately connected to said plurality of pressure chambers; a plurality of recovery manifolds for recovering said liquid from said plurality of recovery flow paths; further comprising a recovery reservoir connected to said plurality of recovery manifolds for recovering said liquid from said plurality of recovery manifolds; wherein said pump is configured to sequentially circulate said liquid through said supply reservoir, said plurality of supply manifolds, said plurality of supply flow paths, said plurality of pressure chambers, said plurality of recovery flow paths, said plurality of recovery manifolds, and said recovery reservoir; each of said plurality of pressure chambers has a pressure chamber body to which pressure is applied by said actuator; and a descender connecting said pressure chamber body and said nozzle; wherein said recovery flow path is connected to said descender; wherein said flow path has a flow path shape such that when said flow rate is said target flow rate, an average viscosity of said liquid in said descender is equal to or greater than 1.5 times an average viscosity of said liquid in said recovery flow path. The device according to claim 1 or 2.

4. Let the cross-sectional area of the inflow surface perpendicular to the flow direction of the liquid in said supply flow path or said recovery flow path be S3. When the cross-sectional area of the outflow surface orthogonal to the flow direction of the liquid of the descender is S4, S4 > S3 The apparatus according to claim 3.

5. When the cross-sectional area of the inflow surface orthogonal to the flow direction of the liquid of the nozzle is S1, When the cross-sectional area of the inflow surface orthogonal to the flow direction of the liquid of the supply flow path or the recovery flow path is S3, S3 > S1 The apparatus according to claim 3 or 4.

6. When the cross-sectional area of the discharge surface orthogonal to the flow direction of the liquid of the nozzle is S2, When the cross-sectional area of the inflow surface orthogonal to the flow direction of the liquid of the supply flow path or the recovery flow path is S3, S3 > S2 The apparatus according to any one of claims 3 to 5.

7. A plurality of recovery flow paths separately connected to the plurality of pressure chambers, A plurality of recovery manifolds for recovering the liquid from the plurality of recovery flow paths, A recovery reservoir connected to the plurality of recovery manifolds and recovering the liquid from the plurality of recovery manifolds, and further comprising: The pump is configured to sequentially circulate the liquid through the supply reservoir, the plurality of supply manifolds, the plurality of supply flow paths, the plurality of pressure chambers, the plurality of recovery flow paths, the plurality of recovery manifolds, and the recovery reservoir, Each of the plurality of pressure chambers, A pressure chamber body to which pressure is applied by the actuator, A descender connecting the pressure chamber body and the nozzle, and has: The recovery flow path is connected to the descender, The descender, A first part, A second part located closer to the pressure chamber body than the first part, and has: The flow path has a flow path shape in which when the flow rate is the target flow rate, the average viscosity of the liquid at the second part is higher than the average viscosity of the liquid at the first part. The apparatus according to any one of claims 1 to 6.

8. Let the fluid resistance of the liquid in the supply reservoir be R ｒ , Let the fluid resistance of the liquid in the supply manifold be R ｍ , The number of the supply manifolds connected to the supply reservoir is m, The number of the nozzles for each supply manifold is n, The flow rate of the liquid flowing into the supply reservoir is U, The surface tension of the liquid is σ, When the radius of the nozzle is r, (1 / 2) × R ｒ × U(1 + 1 / m), and (1 / 2) × R ｍ The sum with (U / m) × (1 + 1 / n) is Less than 2σ / r, and R ｒ < 1 / 10 × R ｍ × (1 / m) The apparatus according to any one of claims 1 to 7.

9. Let the fluid resistance of the liquid in the nozzle be R ｎ when R ｍ < 1 / 10 × R ｎ × (1 / n) The apparatus according to claim 8.

10. A method using the apparatus according to any one of claims 1 to 9, As the liquid, a pseudoplastic fluid having a viscosity of 0.02 Pa·s or more and 0.4 Pa·s or less when the shear rate is 1000 s －１ and having a viscosity of 0.5 Pa·s or more and 50 Pa·s or less when the shear rate is 0.01 s －１ is used Method.

11. The device according to any one of claims 1 to 9, wherein the pump is a vacuum pump.

12. The device according to any one of claims 1 to 9 and 11, wherein the target flow rate is 50 ml / min or more and 300 ml / min or less.

13. When the cross-sectional area of the inflow surface orthogonal to the flow direction of the liquid of the nozzle is S1, and the cross-sectional area of the discharge surface orthogonal to the flow direction of the liquid of the nozzle is S2, S1 > S2 The device according to any one of claims 1 to 12.

14. Including a flow path configured such that a predetermined liquid having pseudoplasticity flows, the flow path comprising: a supply reservoir; a plurality of supply manifolds connected to the supply reservoir; two or more in number for each of the plurality of supply manifolds, each connected to any one of the plurality of supply manifolds, and a plurality of supply flow paths through which the liquid is supplied from the connected supply manifold; a plurality of pressure chambers connected separately to the plurality of supply flow paths and through which the liquid is supplied from the plurality of supply flow paths; a plurality of recovery flow paths connected separately to the plurality of pressure chambers and recovering the liquid from the plurality of pressure chambers; a plurality of recovery manifolds each connected to two or more of the plurality of recovery flow paths and recovering the liquid from the plurality of recovery flow paths; a flow path member having a recovery reservoir connected to the plurality of recovery manifolds and recovering the liquid from the plurality of recovery manifolds; an actuator configured to apply pressure to the liquid in the plurality of pressure chambers and discharge droplets from a plurality of nozzles connected one-to-one to the plurality of pressure chambers; a tank configured to store a part of the liquid and connected to the supply reservoir and the recovery reservoir; a pump configured to sequentially circulate the liquid through the supply reservoir, the plurality of supply manifolds, the plurality of supply flow paths, the plurality of pressure chambers, the plurality of recovery flow paths, the plurality of recovery manifolds, and the recovery reservoir; a controller configured to adjust the circulation flow rate of the liquid to a predetermined target flow rate; and a moving part configured to move at least one of the flow path member or the object surface so that the droplets discharged from the plurality of nozzles move toward the object surface. An apparatus having a channel shape such that when the circulation flow rate is equal to the target flow rate, the average viscosity of the liquid in the plurality of supply channels is half or less of the average viscosity of the liquid in the plurality of supply manifolds.

15. A method comprising: circulating a pseudoplastic liquid through a supply reservoir included in a channel member, a plurality of supply manifolds connected to the supply reservoir, a plurality of supply channels each connected to two or more of the plurality of supply manifolds, a plurality of pressure chambers connected one-to-one to the plurality of supply channels, a plurality of recovery channels connected one-to-one to the plurality of pressure chambers, a plurality of recovery manifolds each connected to two or more of the plurality of recovery channels, and a recovery reservoir connected to the plurality of recovery manifolds; applying pressure to the liquid in the plurality of pressure chambers to eject droplets from a plurality of nozzles connected one-to-one to the plurality of pressure chambers; adjusting the circulation flow rate of the liquid to a target flow rate at which the average viscosity of the liquid in the plurality of supply channels is half or less of the average viscosity of the liquid in the plurality of supply manifolds.

16. The method according to claim 15, wherein at least one of the channel member or the object surface is moved so that the droplets ejected from the plurality of nozzles move toward the object surface.

17. The method according to claim 15 or 16, wherein when the circulation flow rate is the target flow rate, the average viscosity of the liquid in the plurality of supply manifolds is half or less of the average viscosity of the liquid in the supply reservoir.

18. Each of the plurality of pressure chambers has a pressure chamber body to which pressure is applied by an actuator, and a descender connecting the pressure chamber body to the corresponding nozzle, wherein the recovery channel is connected to the descender, and the method according to any one of claims 15 to 17, wherein when the circulation flow rate is the target flow rate, the average viscosity of the liquid in the descender is 1.5 times or more of the average viscosity of the liquid in the plurality of recovery channels.

19. Each of the plurality of pressure chambers has a pressure chamber body to which pressure is applied by a pressurizing unit, and a descender connecting the pressure chamber body to the corresponding nozzle, wherein the recovery channel is connected to the descender, and the descender includes a first portion, and a second portion located closer to the pressure chamber body than the first portion. The method according to any one of claims 15 to 18, wherein when the circulation flow rate is the target flow rate, the average viscosity of the liquid in the second portion is higher than the average viscosity of the liquid in the first portion.

20. Let the fluid resistance of the liquid in the supply reservoir be R ｒ , Let the fluid resistance of the liquid in the supply manifold be R ｍ , Let m be the number of the supply manifolds connected to the supply reservoir, let n be the number of the nozzles for each supply manifold, let U be the flow rate of the liquid flowing into the supply reservoir, let σ be the surface tension of the liquid, and let r be the radius of the nozzle. When these are defined as such, (1 / 2) × R ｒ × U(1 + 1 / m), and (1 / 2)×R ｍ the sum with (U / m)×(1 + 1 / n) is it is smaller than 2σ / r, and R ｒ < 1 / 10 × R ｍ × (1 / m) the method according to any one of claims 15 to 19.

21. Let the fluid resistance of the liquid in the nozzle be R ｎ When R ｍ < 1 / 10 × R ｎ × (1 / n) The method according to claim 20.

22. As the liquid, a pseudoplastic fluid having a viscosity of 0.02 Pa·s or more and 0.4 Pa·s or less when the shear rate is 1000 s －１ and having a viscosity of 0.5 Pa·s or more and 50 Pa·s or less when the shear rate is 0.01 s －１ is used The method according to any one of claims 15 to 21.

23. The target flow rate is 50 ml / min or more and 300 ml / min or less, the method according to any one of claims 15 to 22.

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