KR20220015669A - Inkjet head assembly and inkjey head cleaning method - Google Patents

Abstract

The present invention provides an inkjet head assembly and a cleaning method for effectively removing fine residual ink adhering to an inside of a nozzle. According to an embodiment of the present invention, cleaning efficiency is increased by including a polymer solution which undergoes a phase change at a relatively low temperature in a cleaning solution, trapping particles adhering to an inner wall of the nozzle, and then removing the particles by a rinse liquid. Furthermore, cleaning process is simplified and feeding of the cleaning solution is facilitated by feeding the cleaning solution in a liquid phase. In addition, remaining of the particles on the nozzle after the cleaning is minimized. Moreover, processing cost is reduced by reusing the cleaning solution by adding a filtering process and a concentration adjustment process. The inkjet head assembly comprises: an inkjet head; a cover unit; a cleaning solution feeding unit; a first heat treatment unit; a second heat treatment unit; and a gas feeding unit.

Description

Inkjet head assembly and inkjet head cleaning method

The present invention relates to an inkjet head assembly and a method for cleaning the inkjet head.

In the manufacture of a flat panel display device such as a liquid crystal display device and an organic EL device, a process of applying a chemical solution for forming an alignment layer, a color filter, and the like is performed.

The application of the chemical mainly uses an inkjet head having a nozzle surface. As time passes, chemical liquid residues may be adsorbed on the inner wall of the nozzle surface of the inkjet head, which may affect the application of the chemical liquid. For example, in the case of a water-insoluble ink, since evaporation occurs actively due to high vapor pressure, it is easily cured and solidified. Accordingly, residual ink such as a dispersant or pigment may be cured and adsorbed on the inner wall of the nozzle or the inner wall of the ink passage. When an ink containing nanoparticles or quantum dots is used, aggregation of nanoparticles occurs easily due to a large surface area. Accordingly, nanoparticles or aggregates in which nanoparticles are aggregated may be adsorbed to the inner wall of the nozzle. If chemical liquid residues remain inside the nozzle surface, chemical liquid may be mixed, etc., and may affect the discharge of chemical liquid, which may act as a cause of device failure. However, there is a problem in that it is not easy to remove the solid-type residual ink as described above.

Republic of Korea Patent Publication No. 10-1045469 (June 23, 2011)

SUMMARY OF THE INVENTION The present invention is to solve the above problems, and an object of the present invention is to provide an inkjet head assembly and an inkjet head cleaning method capable of effectively removing fine residual ink adhered to the inside of a nozzle.

The object of the present invention is not limited to the above, and other objects and advantages of the present invention not mentioned can be understood by the following description.

The present invention provides an inkjet head having one or a plurality of nozzles for discharging a chemical onto a substrate; a cover part provided on a lower surface of the inkjet head to allow a liquid to be stored in the nozzle; a cleaning liquid supply unit supplying a liquid cleaning liquid containing a thermally reactive polymer resin to the inside of the nozzle; a first heat treatment unit configured to phase-change the cleaning solution supplied to the inside of the nozzle through a first heat treatment to form a gel; a second heat treatment unit configured to phase change the gelled washing liquid back to a liquid phase through a second heat treatment; It is possible to provide an inkjet head assembly including a gas supply unit for supplying the drying gas to the nozzle.

The cover part may be configured to block the lower surface of the nozzle when the cleaning liquid is supplied, and to open the lower surface of the nozzle when the cleaning liquid is discharged.

In this case, the heat-reactive polymer resin is a material that gels when heated above the phase change temperature and liquefies when cooled below the phase change temperature, the first heat treatment means is a heating means, and the second heat treatment means can be a cooling means. .

Alternatively, the heat-reactive polymer resin is a material that liquefies when heated above the phase change temperature and gels when cooled below the phase change temperature, the first heat treatment means is a cooling means, and the second heat treatment means can be a heating means .

In addition, the receiving unit for accommodating the discharged liquid discharged after washing; a filtering unit for filtering the discharged liquid to remove particles; It may further include a concentration control unit for adjusting the concentration so that the filtered solution can be reused as a cleaning solution.

The present invention comprises the steps of blocking the discharge port of the inkjet head; supplying a liquid cleaning solution containing a thermally reactive polymer resin to the inkjet head; trapping particles by gelling the liquid washing solution through a phase change through a first heat treatment; liquefying the washing solution in a gel state that traps particles through a second heat treatment; opening a discharge port of the inkjet head; and supplying and discharging a rinse liquid to the liquid phase-changed cleaning liquid.

The heat-reactive polymer resin may be gelled when heated above the phase change temperature and liquefied when cooled below the phase change temperature.

The heat-reactive polymer resin is Poly(N-isopropylacrylamide), Poly(N, N-diethylacrylamide), Poly(Nethylmethacylamide), Poly(methyl vinyl ether), Poly(2-ethoxyethyl vinyl ether), Poly(Nvinylcaprolactam), Poly( N-vinylisobutyramide), Poly(NN-vinyl-n-butyramide), Poly(dimethylaminoethyl methacrylate), Poly(N-(L)-(1-hydroxymethyl) propyl methacrylamide, Poly(ethyleneglycol)/(poly(lactide-co-) glycolide), polyoxyethylene-polyoxypropylene, polyoxyethylenepolyoxypropylene-polyoxyethylene, and poly(ethylene glycol)-poly(lactic acid)-poly(ethylene glycol).

Alternatively, the heat-reactive polymer resin may be liquefied when heated above the phase change temperature and gelled when cooled below the phase change temperature.

The heat-reactive polymer resin is Gelatin, Poly(N-acryloylglycinamide), Poly(acrylamide-co-acrylonitrile), Poly(methacrylamide), Poly(acrylic acid), Poly(allylamine-co-allylurea), Poly(ethylene oxide), Poly(vinylmethylether), Poly(hydroxyethyl methacrylate), N-vinylimidazole, and may include at least one of 1-vinyl-2-(hydroxylmethyl)imidazole.

The phase change temperature of the thermally reactive polymer resin may be in the range of 20°C to 50°C.

The solvent of the washing solution may be a polar protic solvent.

The solvent of the washing solution may include at least one of pure water (H20), methanol (CH3OH), ethanol (C2H5OH), IPA, and acetic acid (CH3COOH).

The rinse solution may have the same component as the solvent of the cleaning solution.

In this case, the method may further include: filtering the discharged solution in which the washing solution and the rinse solution are mixed and then recycling the washing solution; adjusting the concentration of the filtered solution.

In the step of adjusting the concentration of the filtered solution, the concentration may be controlled by evaporating the solvent from the filtered solution or by adding a thermally reactive polymer resin to the filtered solution.

According to an embodiment of the present invention, the cleaning efficiency can be increased by supplying a liquid cleaning liquid to the inkjet head, changing the cleaning liquid to a gel state through heat treatment, trapping particles attached to the inner wall of the nozzle, and then removing it with a rinse liquid. . Moreover, the cleaning process is simplified, and the cleaning liquid is easily supplied in a liquid phase.

In addition, according to an embodiment of the present invention, since the gelled cleaning solution is liquefied again to trap the particles and then rinsed, it is possible to minimize the particles remaining in the nozzle after cleaning.

In addition, according to an embodiment of the present invention, when a solvent used in the cleaning solution is used as the rinse solution, the solution discharged after cleaning becomes a low concentration cleaning solution, so the concentration control process (adding polymer, solution Evaporation, etc.) and reuse as a cleaning solution can reduce process costs.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a block diagram schematically showing an inkjet head assembly according to the present invention.
2 is a schematic side view of a part of an inkjet head assembly according to the present invention.
3 is a schematic diagram illustrating an inkjet head cleaning method according to an embodiment of the present invention.
4 is a flowchart schematically illustrating an inkjet head cleaning method according to an embodiment of the present invention.
5 is a flowchart schematically illustrating an inkjet head cleaning method according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention, a detailed description thereof may be omitted for parts not related to the essence of the present invention, and the same reference numerals may be assigned to the same or similar elements throughout the specification.

In addition, in the referenced drawings, the size of the component, the thickness of the line, etc. may be slightly exaggerated or reduced for convenience of understanding.

In addition, when a part "includes" a certain component, this means that other components may be further included rather than excluding other components unless otherwise stated. The terminology used herein is only for referring to specific embodiments and is not intended to limit the present invention, and unless otherwise defined in the present specification, is a concept understood by those of ordinary skill in the art to which the present invention pertains. can be interpreted.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

1 is a block diagram schematically showing an inkjet head assembly according to the present invention.

The inkjet head assembly 100 supplies a processing liquid to the substrate S. The inkjet head assembly 100 includes one or a plurality of inkjet heads 110 provided with a nozzle 112 for discharging a chemical onto a substrate S, and provided on a lower surface of the inkjet head 110 to form the nozzles 112 . The cover part 120 capable of blocking the discharge port, the cleaning liquid supply unit 130 for supplying the cleaning liquid to the inside of the nozzle 112, the first heat treatment unit 140 for gelling the cleaning liquid, and a phase change of the cleaning liquid back to a liquid phase The second heat treatment unit 150 and the gas supply unit 160 for supplying dry gas to the inside of the nozzle 112 may be included.

One or a plurality of inkjet heads 110 may be provided, and when a plurality of inkjet heads 110 are provided, different types of treatment liquids may be supplied. Sources of each treatment liquid may be respectively provided in the treatment liquid supply unit, and may be supplied to the inkjet head 110 from each treatment liquid source when substrate processing is performed. Each treatment liquid supply source may include a separate valve for controlling supply and shutoff of each treatment liquid. The treatment liquid may be a chemical, a rinse liquid, and an organic solvent. The chemical may be a liquid having acid or basic properties. Chemicals may include sulfuric acid (H2SO4), phosphoric acid (P2O5), hydrofluoric acid (HF) and ammonium hydroxide (NH4OH). The chemical may be a mixed solution of Diluted Sulfuric Acid Peroxide (DSP). The rinse solution may be a polar protic solvent such as pure water (H20), methanol (CH3OH), ethanol (C2H5OH), IPA, acetic acid (CH3COOH), or the like. The organic solvent may be isopropyl alcohol (IPA) liquid. The inkjet head 110 may include a nozzle 112 .

The cover part 120 is provided on the lower surface of the inkjet head 110 as shown in FIG. 2 to block or open the discharge port of the nozzle 112 . When the outlet of the nozzle 112 is blocked by the cover part 120 , the fluid may be stored in the nozzle 112 . The cover part 120 maintains the discharge port of the nozzle 112 open when the substrate processing process is performed, and a separate control unit (not shown) so that the discharge port is blocked and opened when the inkjet head 100 is cleaned. city) can be controlled by Specifically, the cover part 120 blocks the discharge port of the nozzle 112 before the cleaning liquid is supplied to the nozzle 112, and controls the nozzle 112 to open the discharge port when the cleaning liquid is discharged through a series of processes. can be In the present specification, although the example in which the cover part 120 is integrally configured to open and close the cover parts of all nozzles at the same time has been exemplified, the cover parts of each nozzle may be configured separately for each nozzle.

The cleaning liquid supply unit 130 supplies a liquid cleaning liquid containing a thermally reactive polymer resin to the inside of the inkjet head 110 when the discharge port of the nozzle 112 is blocked by the cover part 120 . In this case, as the solvent of the cleaning solution, a polar protic solvent having a high dielectric constant and high polarity may be applied. For example, the solvent may include at least one of pure water (H20), methanol (CH3OH), ethanol (C2H5OH), IPA, and acetic acid (CH3COOH). The supplied cleaning liquid is stored in the nozzle 112 by the cover part 120 . A thermally reactive polymer resin undergoes a phase transition according to a change in temperature. Therefore, the particles attached to the inner wall of the nozzle 112 can be separated from and discharged from the inner wall of the nozzle 112 by heat-treating the liquid cleaning solution containing the thermally reactive polymer resin.

In the present invention, the treatment liquid supply unit and the cleaning liquid supply unit 130 have been separately described for convenience of explanation, but one of the sources provided in the treatment liquid supply unit supplies the liquid cleaning liquid containing the thermally reactive polymer resin. It can also be configured.

The first heat treatment unit 140 may phase-change the cleaning solution stored in the nozzle 112 through the first heat treatment to make it gel. At this time, as the liquid cleaning liquid is gelled, particles attached to the inner wall of the nozzle 112 may be separated from the inner wall of the nozzle 112 while being trapped in the cleaning liquid.

The second heat treatment unit 150 may change the phase of the cleaning liquid stored in the nozzle 112 back to a liquid phase through the second heat treatment. The liquid phase-changed cleaning liquid again contains particles separated from the inner wall of the nozzle 112 . In order to remove the cleaning liquid and particles that have been changed to liquid phase by the second heat treatment, a rinse liquid may be supplied from the processing liquid supply unit inside the inkjet head 110 . At this time, the discharge port of the nozzle 112 is opened again by the cover part 120 , and the liquid cleaning liquid, particles, and rinse liquid may be discharged from the inkjet head 110 in a mixed state. For ease of mixing of the cleaning liquid and the rinse liquid, the rinse liquid is preferably the same component as the solvent of the cleaning liquid.

At this time, when the heat-reactive polymer resin is a material that gels when heated above the phase change temperature and liquefies when cooled below the phase change temperature, the first heat treatment means may be a heating means, and the second heat treatment means may be a cooling means. Conversely, when the heat-reactive polymer resin is a material that liquefies when heated above the phase change temperature and gels when cooled below the phase change temperature, the first heat treatment means is a cooling means, and the second heat treatment means is a heating means can

The heating means and the cooling means may be a heater provided in the inkjet head 110, a refrigerant passage, or the like, or a means for supplying a gas whose temperature is adjusted to the inside of the nozzle 112, but may be various means, but not limited thereto. have. In some cases, the heating means and the cooling means may be configured as one means capable of performing both heating and cooling functions.

The gas supply unit 160 supplies a drying gas to the inkjet head 110 to dry the inside of the inkjet head 110 from which the discharged liquid has been discharged after cleaning the inkjet head 110 . The inside of the nozzle 112 and the inkjet head 110 cleaned by the drying gas may be dried.

On the other hand, the inkjet head assembly 100 according to the present invention includes an accommodating part 170 for accommodating the discharged liquid containing the used cleaning liquid, and a filtering unit for removing particles by filtering the discharged liquid accommodated in the accommodating part 170 ( 180), it may be configured to further include a concentration control unit 190 for adjusting the concentration in order to reuse the filtered solution as a cleaning solution. Process costs can be reduced by reusing the cleaning solution.

3 and 4 are diagrams illustrating an inkjet head cleaning method according to an embodiment of the present invention.

3 and 4, the inkjet head cleaning method according to an embodiment of the present invention includes a discharge port blocking step (S10), a cleaning solution supply step (S20), a cleaning solution heat treatment step (S30), an outlet opening step (S40), It includes a washing solution discharging step (S50) and a drying step (S60).

In the discharge port blocking step (S10), the discharge port of the nozzle included in the inkjet head is blocked as shown in FIG. 3(b). By blocking the discharge port, the cleaning liquid may be stored inside the nozzle.

In the cleaning liquid supply step S20 , the cleaning liquid 1 is supplied to the inkjet head whose discharge port is blocked. The cleaning liquid 1 may be supplied to the nozzle from a cleaning liquid source connected to the inkjet head.

In one embodiment according to the present invention, a solution containing a thermally reactive polymer resin in a solvent is used as the cleaning solution. In this case, as the solvent of the cleaning solution, a polar protic solvent having a high dielectric constant and high polarity may be applied. For example, the solvent may include at least one of pure water (H20), methanol (CH3OH), ethanol (C2H5OH), IPA, and acetic acid (CH3COOH).

On the other hand, the heat-reactive polymer resin applied to an embodiment of the present invention can be applied to a polymer resin having a relatively low phase change temperature (LCST; Lower Critical Solution Temperature) in the range of 20 ℃ ~ 50 ℃. Accordingly, the cleaning solution supplied to the substrate may be phase-changed to a gel state through heat treatment such as heating or cooling at a relatively low temperature.

In this case, the thermally reactive polymer resin may be a polymer resin that gels when heated above the phase change temperature and liquefies when cooled below the phase change temperature.

For example, the thermoreactive polymer resin is Poly(N-isopropylacrylamide), Poly(N, N-diethylacrylamide), Poly(Nethylmethacylamide), Poly(methyl vinyl ether), Poly(2-ethoxyethyl vinyl ether), Poly(Nvinylcaprolactam) , Poly(N-vinylisobutyramide), Poly(NN-vinyl-n-butyramide), Poly(dimethylaminoethyl methacrylate), Poly(N-(L)-(1-hydroxymethyl) propyl methacrylamide, Poly(ethyleneglycol)/(poly(lactide) -co-glycolide), polyoxyethylene-polyoxypropylene, polyoxyethylenepolyoxypropylene-polyoxyethylene, and poly(ethylene glycol)-poly(lactic acid)-poly(ethylene glycol).

Alternatively, the thermally reactive polymer resin may be a polymer resin that liquefies when heated above the phase change temperature and gels when cooled below the phase change temperature.

For example, the thermoreactive polymer resin is Gelatin, Poly(N-acryloylglycinamide), Poly(acrylamide-co-acrylonitrile),

Poly(methacrylamide), Poly(acrylic acid), Poly(allylamine-co-allylurea), Poly(ethylene oxide), Poly(vinylmethylether), Poly(hydroxyethyl methacrylate), N-vinylimidazole, 1-vinyl-2-(hydroxylmethyl) at least one of imidazole.

The washing solution heat treatment step (S30) includes a first heat treatment step (S31) of gelling the washing solution (1) and a second heat treatment step (S32) of liquefying the washing solution in a gel state again.

In the first heat treatment step ( S31 ), the cleaning solution 1 supplied to the inkjet head is phase-changed through heat treatment to form the cleaning solution 1 in a gel state.

As the phase change of the cleaning liquid 1 into a gel state, the volume of the cleaning liquid 1 changes. Accordingly, the phase-changed cleaning material traps particles P attached to the inkjet head, particularly the nozzle inner wall.

For example, when a thermally reactive polymer that changes phase from a liquid to a gel state by heating above the phase change temperature of the cleaning liquid 1 of the first embodiment is applied, the liquid cleaning liquid containing the thermally reactive polymer is injected into the inkjet head and , when heated above the phase change temperature of the thermally-reactive polymer solution, the thermally-reactive polymer solution changes from a liquid phase to a gel state.

As the thermally reactive polymer solution gels as shown in FIG. 3(c) , the cleaning solution 1 in a gel state traps the particles P attached to the substrate. Accordingly, the particles P may be separated from the inner wall of the inkjet head.

In the second heat treatment step (S32), as shown in Fig. 3(d), the phase change of the washing liquid 1 to a gel state is again changed to a liquid phase through heat treatment.

When the cleaning liquid in the gel state is phase changed to the liquid phase through the second heat treatment step S32, it becomes easier to remove the cleaning liquid from the surface of the substrate in the subsequent rinse step.

In the discharge opening step S40 , the discharge port of the nozzle included in the inkjet head on which the second heat treatment step S32 is completed is opened. This is to discharge the cleaning liquid 1 stored in the nozzle in the next step by opening the discharge port.

The rinsing step (S50) is a step of supplying a rinse liquid to the substrate to remove the cleaning liquid 1 and particles P trapped in the cleaning liquid 1 from the surface of the substrate, and the cleaning liquid 1 and the rinse liquid are mixed is discharged to the outside of the inkjet head through the drain line.

After the rinse step (S50), a drying step (S60) may be performed to dry the cleaned inkjet head. In the drying step (S60), a drying gas may be injected into the inkjet head to dry the rinse solution remaining in the inkjet head.

As described above, in the present invention, since a solution that changes phase from a liquid to a gel at a relatively low temperature is used as a cleaning solution, particles can be effectively removed without a high-temperature heating process for solidification or hardening.

In addition, since the cleaning liquid 1 is supplied to the substrate in a liquid state, it is easy to supply the cleaning liquid, and after phase change of the gelled cleaning liquid back to liquid, it is removed using a rinse liquid having the same component as the solvent of the cleaning liquid, so expensive peeling treatment A liquid or a dissolution treatment liquid is unnecessary, and there is no problem that the polymer remains on the surface of the substrate.

In addition, since the particles P are trapped by the cleaning liquid 1 while the cleaning liquid 1 is gelled, the problem of damage to the inside of the inkjet head during the cleaning process is prevented.

5 is a diagram illustrating a cleaning method of an inkjet head according to another embodiment of the present invention.

Referring to FIG. 5 , the cleaning method of the inkjet head according to another embodiment includes a discharge port blocking step (S10), a cleaning solution supply step (S20), a cleaning solution heat treatment step (S30), an outlet opening step (S40), and a cleaning solution discharge step (S50). ), a drying step (S60), and a washing solution reuse step (S70).

That is, the method for cleaning an inkjet head according to another embodiment of the present invention is similar to the method for cleaning the inkjet head according to the embodiment, but the method for cleaning the inkjet head according to another embodiment further includes a cleaning solution reuse step. Accordingly, a detailed description of a configuration similar to the inkjet head cleaning method according to the exemplary embodiment will be omitted below.

The washing solution reuse step (S70) is to reuse the used washing solution by filtering (S71).

That is, the cleaning solution 1 that traps particles P attached to the inner wall of the inkjet head in a gel state is changed to a liquid phase again and is discharged together with the rinse solution. The discharged rinse liquid and cleaning liquid may be collected by providing a separate accommodating part. In this case, when the same solvent as the solvent of the rinse solution is used, the rinse solution may have the same components as the cleaning solution except for the thermally reactive polymer resin. That is, if only the particles P are removed by filtering the discharged solution accommodated in the receiving unit, the initially supplied cleaning solution 1 becomes the same as the diluted component. Therefore, after the step of adjusting the concentration of the filtered cleaning solution (S72), the solution that has passed through the accommodating part and the filter can be reused as a cleaning solution.

In this case, as a method of controlling the concentration of the washing solution, the concentration of the washing solution may be adjusted by evaporating the solvent from the filtered solution, or the concentration of the washing solution may be adjusted by adding a thermally reactive polymer resin to the filtered solution.

As described above, in the embodiment of the present invention, when a rinse solution having the same component as the solvent used in the cleaning solution is used, the solution discharged to the drain line after cleaning the substrate becomes a low concentration cleaning solution. Process costs can be reduced by reusing it as a cleaning solution through a conditioning process (addition of polymer, evaporation of solution, etc.).

According to the inkjet head assembly and the inkjet head cleaning method according to the present invention, a liquid cleaning liquid is supplied to the inkjet head, and the cleaning liquid is phase-changed to a gel state through heat treatment to trap particles attached to the inner wall of the nozzle and then removed with a rinse liquid. By doing so, the cleaning efficiency can be improved. Moreover, the cleaning process is simplified and the cleaning liquid is easily supplied in a liquid phase.

In addition, since the gelled cleaning solution is liquefied again to trap particles by using a polymer resin having a relatively low phase change temperature and then rinsed, it is possible to minimize the particles remaining in the nozzle after cleaning, and damage to the inside of the inkjet head due to cleaning can prevent

In addition, if the solvent used in the cleaning liquid is used as the rinse liquid, the solution discharged after cleaning becomes a low-concentration cleaning liquid, so only particles are removed through filtering and then reused as a cleaning liquid through a concentration control process (polymer addition, solution evaporation, etc.) This can reduce the process cost.

Those skilled in the art to which the present invention pertains should understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential characteristics thereof, so the embodiments described above are illustrative in all respects and not restrictive. only do

The scope of the present invention is indicated by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. .

100; inkjet assembly
110; inkjet head
112; Nozzle
120; cover
130; cleaning liquid supply unit
140; first heat treatment unit
150; second heat treatment unit
160; dry gas supply unit
170; receptacle
180; filtering unit
190; concentration control unit

Claims (16)

an inkjet head provided with one or a plurality of nozzles for discharging a chemical onto a substrate;
a cover part provided on a lower surface of the inkjet head to allow a liquid to be stored in the nozzle;
a cleaning liquid supply unit supplying a liquid cleaning liquid containing a thermally reactive polymer resin to the inside of the nozzle;
a first heat treatment unit configured to phase-change the cleaning solution supplied to the inside of the nozzle through a first heat treatment to form a gel;
a second heat treatment unit configured to phase change the gelled washing liquid back to a liquid phase through a second heat treatment;
a gas supply unit supplying drying gas to the nozzle;
An inkjet head assembly comprising a.
According to claim 1,
The cover part is configured to block a lower surface of the nozzle when the cleaning liquid is supplied, and to open the lower surface of the nozzle when the cleaning liquid is discharged.
According to claim 1,
The heat-reactive polymer resin is a material that gels when heated above the phase change temperature and liquefies when cooled below the phase change temperature,
The first heat treatment means is a heating means, and the second heat treatment means is a cooling means.
According to claim 1,
The heat-reactive polymer resin is a material that liquefies when heated above the phase change temperature and gels when cooled below the phase change temperature,
The first heat treatment means is a cooling means, and the second heat treatment means is a heating means.
The method of claim 1,
a receiving unit accommodating the discharged liquid discharged after washing;
a filtering unit filtering the discharged liquid to remove particles;
a concentration control unit for adjusting the concentration so that the filtered solution can be reused as a cleaning solution;
The inkjet head assembly further comprising a.
blocking the discharge port of the inkjet head;
supplying a liquid cleaning solution containing a thermally reactive polymer resin to the inkjet head;
trapping particles by gelling the liquid washing solution through a phase change through a first heat treatment;
liquefying the washing solution in a gel state that traps particles through a second heat treatment;
opening a discharge port of the inkjet head; and
supplying and discharging a rinse liquid to the liquid phase-changed cleaning liquid;
Inkjet head cleaning method comprising a.
7. The method of claim 6,
The heat-reactive polymer resin is an inkjet head cleaning method, characterized in that when heated above the phase change temperature, it gels, and when cooled below the phase change temperature, it liquefies.
8. The method of claim 7,
The heat-reactive polymer resin is Poly(N-isopropylacrylamide), Poly(N, N-diethylacrylamide), Poly(Nethylmethacylamide), Poly(methyl vinyl ether), Poly(2-ethoxyethyl vinyl ether), Poly(Nvinylcaprolactam), Poly( N-vinylisobutyramide), Poly(NN-vinyl-n-butyramide), Poly(dimethylaminoethyl
methacrylate), Poly(N-(L)-(1-hydroxymethyl) propyl methacrylamide, Poly(ethyleneglycol)/(poly(lactide-co-glicolide), Polyoxyethylene-polyoxypropylene, polyoxyethylenepolyoxypropylene-polyoxyethylene, Poly(ethylene glycol)-poly( An inkjet head cleaning method comprising at least one of lactic acid)-poly(ethylene glycol).
7. The method of claim 6,
The heat-reactive polymer resin is liquefied when heated above the phase change temperature, and gelled when cooled below the phase change temperature.
10. The method of claim 9,
The heat-reactive polymer resin is Gelatin, Poly(N-acryloylglycinamide), Poly(acrylamide-co-acrylonitrile), Poly(methacrylamide), Poly(acrylic acid), Poly(allylamine-co-allylurea), Poly(ethylene oxide), An inkjet head cleaning method comprising at least one of poly(vinylmethylether), poly(hydroxyethyl methacrylate), N-vinylimidazole, and 1-vinyl-2-(hydroxylmethyl)imidazole.
7. The method of claim 6,
The phase change temperature of the thermally reactive polymer resin is an inkjet head cleaning method, characterized in that in the range of 20 ℃ ~ 50 ℃.
7. The method of claim 6,
Inkjet head cleaning method, characterized in that the solvent of the cleaning solution is a polar protic solvent (Polar Protic Solvent).
13. The method of claim 12,
The solvent of the cleaning solution includes at least one of pure water (H20), methanol (CH3OH), ethanol (C2H5OH), IPA, and acetic acid (CH3COOH).
7. The method of claim 6,
The rinse liquid is an inkjet head cleaning method, characterized in that the same component as the solvent of the cleaning liquid is applied.
15. The method of claim 14,
Filtering the discharged liquid in which the cleaning liquid and the rinse liquid are mixed and then recycling it as a cleaning liquid;
adjusting the concentration of the filtered solution;
Inkjet head cleaning method further comprising a.
16. The method of claim 15,
The step of adjusting the concentration of the filtered solution.
An inkjet head cleaning method, characterized in that the concentration is controlled by evaporating a solvent from the filtered solution or adding a thermally reactive polymer resin to the filtered solution.

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