CN109624481B

CN109624481B - Dampening water applying method based on combination of electrowetting and ultrasonic atomization, system and application thereof

Info

Publication number: CN109624481B
Application number: CN201910093709.3A
Authority: CN
Inventors: 田森林; 赵群; 黄建洪; 李英杰; 胡学伟; 宁平; 宋玉新; 蒋仕飞
Original assignee: Kunming University of Science and Technology
Current assignee: Kunming University of Science and Technology
Priority date: 2019-01-30
Filing date: 2019-01-30
Publication date: 2020-10-23
Anticipated expiration: 2039-01-30
Also published as: CN109624481A

Abstract

The invention discloses a dampening water applying method based on combination of electrowetting and ultrasonic atomization as well as a system and application thereof, wherein the method comprises the following steps: 1) an ultrasonic atomization device is arranged below the water roller, dampening water is added into the ultrasonic atomization device, and an atomization nozzle of the ultrasonic atomization device is provided with an electrode; 2) the water roller comprises a metal roller and a dielectric layer covering the outer surface of the metal roller; starting an ultrasonic atomization device, and ultrasonically atomizing fountain water onto a water roller under the ultrasonic condition; 3) and electrifying the electrode at the atomizing nozzle and the metal rod at the same time, and starting the water roller to transfer the dampening water from the water roller to the printing plate in a continuous and uniform water film manner. The invention creatively adopts the principle of combining electrowetting and ultrasonic atomization to apply the dampening water, can greatly reduce the surface tension of the dampening water, and stably and uniformly adheres to the surface of the water roller to form a water film.

Description

Dampening water applying method based on combination of electrowetting and ultrasonic atomization, system and application thereof

Technical Field

The invention belongs to the technical field of printing, and particularly relates to a dampening water applying method based on combination of electrowetting and ultrasonic atomization, and a system and application thereof.

Background

The offset printing is that when printing, the image-text part and the non-image-text part on the printing plate are almost on the same plane, in order to enable the ink to distinguish the image-text part and the non-image-text part of the printing plate, firstly, a dampening water applying system of a printing system supplies water to the non-image-text part of the printing plate, then, an ink supplying device of the printing system supplies ink to the printing plate, as the non-image-text part of the printing plate is protected by the water, the ink can only be supplied to the image-text part of the printing plate, finally, the ink on the printing plate is transferred to a rubber blanket, and then the ink on the rubber blanket is transferred to a printing stock by utilizing the pressure between. The water supply device of the printing system utilizes the principle that oil and water are not mutually soluble, and a thin dampening film is coated on the non-image-text part of the printing plate, thereby realizing the smooth printing of the printing ink on the printing plate.

Dampening water is a general name of dampening liquid which mainly comprises water and is added with certain additives in the prior art. Smooth formation of a dampening water film on a printing plate plays an important role in lithography, and in order to make the dampening water film easier to form smoothly, it is necessary to reduce the surface tension of water. Therefore, in the prior art of lithographic printing, it is necessary to add alcohol, isopropyl alcohol (IPA), or other alcohol or ether substitutes to the fountain solution in order to reduce the surface tension of water. However, alcohol, isopropanol or other alcohol and ether substitutes have more disadvantages: 1. isopropanol contains harmful substances, which are volatile substances and cause serious environmental pollution, and in a relatively closed printing workshop, the volatile isopropanol vapor seriously damages the health of operators; 2. alcohol and isopropanol belong to flammable and explosive products, and are very unsafe because the flash point is too low and the alcohol and the isopropanol are easy to combust and explode; 3. the printing cost is increased; 4. more printing problems, severe emulsification, poor printing effect, etc. may be caused. Therefore, it is difficult to add chemical substances such as alcohols and surfactants to reduce the surface tension of the fountain solution for a long time under the trends of green and safe production and environmental protection.

In the prior art, a pure physical method is used for realizing the spreading and film forming of fountain water by distributing a ceramic layer carved with reticulate patterns on a dampening roller, canceling a sand blasting layer on the original dampening roller and physically dividing the fountain water which has larger surface tension and is difficult to form a film into fine water drops on the reticulate patterns, so that no alcohols or ethers are added, and a printed product with better quality is obtained. The method relieves the excessive use of the alcohol fountain solution and the huge pressure on the environment of the existing lithographic printing which has the dominating status in the printing field to a certain extent, but because the method depends heavily on the reticulate structure of the dampening roller, and because the printing system is in mechanical operation, the dampening roller does not need to continuously move transversely and longitudinally, the whipping distance is 5-50mm, and meanwhile, the dampening roller also needs to be in contact with a water bucket roller and a printing roller, even for the purposes of controlling the printing speed, the water supply amount and the like, certain pressure needs to be applied, so that the problems of abrasion, deformation and the like of the reticulate structure on the surface of the dampening roller are difficult to avoid; if the printing quality is not acceptable, the printing quality and the printing date are decreased until the printed product is unqualified.

Electrowetting (EW) refers to a phenomenon in which the wettability of a liquid droplet on a substrate, i.e., the contact angle, is changed by changing the voltage between the liquid droplet and the substrate. In the prior art, electrowetting is widely used in the fields of displays, fluid manipulation, micro zoom lenses, and the like. The ultrasonic wave is a sound wave which has good directivity and strong penetrating power and can be transmitted in water for a long distance. Ultrasonic atomization refers to a process in which liquid is dispersed in a gas phase to form fine droplets under the action of ultrasound. In the prior art, ultrasound and ultrasonic atomization are widely applied to the fields of medicine, air purification and the like. However, the combined use of electrowetting and ultrasonic atomization for dampening water application and lithographic printing has not been reported.

In view of the above problems, there is a need to invent a fountain water application method based on the combination of electrowetting and ultrasonic atomization, and a system and an application thereof.

Disclosure of Invention

The invention aims to provide a fountain water application method based on combination of electrowetting and ultrasonic atomization, aims to provide a fountain water application system based on combination of electrowetting and ultrasonic atomization, and aims to provide application of the fountain water application method based on combination of electrowetting and ultrasonic atomization.

The first object of the present invention is achieved by comprising the steps of:

1) an ultrasonic atomization device is arranged below the water roller, dampening water is added into the ultrasonic atomization device, and an atomization nozzle of the ultrasonic atomization device is provided with an electrode;

2) the water roller comprises a metal roller and a dielectric layer covering the outer surface of the metal roller; starting an ultrasonic atomization device, and ultrasonically atomizing fountain water onto a water roller under the ultrasonic wave of 0.1-100 MHz;

3) and electrifying the electrode at the atomizing nozzle and the metal rod at the same time, and starting the water roller to transfer the dampening water from the water roller to the printing plate in a continuous and uniform water film manner.

The second purpose of the invention is realized by the following steps that the ultrasonic atomization device comprises a closed chain guide rail, a chain driving mechanism, a moving rod, an ultrasonic atomizer, a dampening water bin and a metal roller, wherein the closed chain guide rail is rectangular, the upper part of the closed chain guide rail is an inwards concave arc-shaped atomization section, the closed chain guide rail is respectively arranged at two ends of the metal roller, a moving chain is arranged in the closed chain guide rail, the chain driving mechanism is connected with the moving chain and is used for driving the moving chain to move in the closed chain guide rail, two ends of the moving rod are respectively connected with the moving chain of the closed chain guide rail and are parallel to the metal roller, a closed atomization working belt is formed among the moving rods, the ultrasonic atomizer is connected with the dampening water bin to form an ultrasonic atomization device, the ultrasonic atomization device is arranged on the moving rod, and the ultrasonic atomizer is positioned outside the atomization working belt, the dampening water bin is positioned in the spraying working band, the metal roller is an electrified roller, the outer surface of the metal roller is covered with a dielectric layer, and the spraying end of the ultrasonic atomizer clamps an electrode.

The third object of the invention is achieved by the use of the method in lithography, in particular comprising the following steps:

1) the dampening water is transferred to the printing plate in a continuous and uniform water film form by the dampening water applying method to form a patterned dampening water film;

2) applying ink to areas of the printing plate not covered by the patterned dampening water film by an ink application system;

3) and transferring the pattern on the printing plate to a rubber blanket, and further transferring the pattern to printing paper to finish printing.

Compared with the prior art, the invention has the following technical effects:

1. the invention creatively adopts the principle of combining electrowetting and ultrasonic atomization to apply the dampening water, can greatly reduce the surface tension of the dampening water, and stably and uniformly adheres to the surface of the water roller to form a water film.

2. The invention applies the dampening water in an ultrasonic atomization mode, the water roller does not need to directly contact the dampening water, and meanwhile, the electrified metal roller is matched with the electrified dampening water to generate an electrowetting effect, so that the dampening water uniformly covers the dielectric layer, and the surface tension of the dampening water is effectively reduced. The invention effectively reduces the consumption of the dampening water, the consumption of the dampening water is only about 50 percent of that of the prior art under the same printing quantity, and the application mode of ultrasonic atomization effectively avoids the problems that the hanging rollers of impurities, microorganisms and the like in the dampening water influence the printing quality and shorten the service life of the water roller, and can degrade organic matters and the like in the dampening water, reduce the content of the organic matters, eliminate pollution and realize clean printing. The invention can flexibly adjust the thickness of the water film and the size of the contact angle by controlling the potential difference, the material thickness of the dielectric layer, the atomization strength and the like, has simple operation and is not limited by the mechanical structure of the water roller.

3. The invention overcomes the problem that the prior art completely depends on the mechanical structure of a flat printing system, and can realize the requirement of printing on a dampening water film only by using a mode of forming the water film on the plate roller and then directly connecting the plate, thereby greatly reducing the requirement of the prior art on all levels of water rollers of a printing water supply system; furthermore, under the condition that a water mixing roller and a water homogenizing roller in the prior art are omitted, the invention can be realized only by reserving the water bucket roller and the plate roller, so that the equipment is simple, the water supply time is shortened, and the efficiency is increased; furthermore, when the uniformity of the water film needs to be further increased, a water distributing roller and/or a water homogenizing roller can be added, and the mode that the water film formed on the traditional water bucket roller or the water conveying roller is transmitted to the printing plate after passing through each stage of water rollers is adopted, so that the water film is more uniform.

4. The invention can realize the purpose of printing for the conventional dampening water added with surface active substances, further can reduce the dosage of the surface active substances, and can realize high-quality printing even for the dampening water without the surface active substances.

5. According to the invention, the spray section of the closed chain guide rail and the moving rod form a sunken structure for accommodating the lower part of the water roller, and the ultrasonic atomization device and the sprayed area of the corresponding water roller form a relatively static working state in the moving process by controlling the speed of the moving chain, so that the ultrasonic atomization spray head can continuously spray to the corresponding area, the effect of flexibly controlling the water hanging amount and the thickness of a water film is realized, and the problems that the water hanging amount is not easy to be high and the water roller is easy to wear because the rotating speed of the water roller is increased in the traditional water bucket type water hanging manner are solved;

6. the dampening water adding device can automatically add dampening water to the dampening water bin in real time in the working process of the system, does not need manual operation, and has the advantages of convenience in operation and management; proximity sensor cooperation controlling means for ultrasonic atomization device begins the spraying when getting into the spraying section, stops the spraying when removing to other positions, realizes exerting dampening water to the water roller automatically.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic structural view of the belt conveyor of FIG. 1 further including a charged chain plate, a movable roller and a tension roller;

FIG. 3 is a left side view of the structure of FIG. 1;

FIG. 4 is a schematic bottom view of the water adding head;

FIG. 5 is a schematic view of the internal structure of a dampening water tank;

FIG. 6 is a schematic view of the structure of the movable platen of FIG. 5 in a state of being pressed downward for adding water

In the figure: 1-closed chain guide rail, 2-chain driving mechanism, 3-movable rod, 4-ultrasonic atomizer, 5-dampening water bin, 5 a-water feeding port, 5 b-movable pressing table, 5 c-limit sealing cover, 5 d-reset spring, 5 e-spring rod, 6-electrified chain plate, 7-metal roller, 8-dielectric layer, 9-proximity sensor, 10 a-dampening water storage tank, 10 b-water feeding pipe, 10 c-water feeding head, 10 d-sliding table, 10 e-water feeding port, 11-electric conductor, 12-sliding contact line, 13-driving roller and 14-tensioning roller.

Detailed Description

The present invention is further illustrated by the following examples and the accompanying drawings, but the present invention is not limited thereto in any way, and any modifications or alterations based on the teaching of the present invention are within the scope of the present invention.

The invention relates to a fountain water application method based on combination of electrowetting and ultrasonic atomization, which comprises the following steps:

Preferably, the dampening water is any one of tap water, deionized water and distilled water.

Preferably, the dielectric layer is any one or more of a ceramic layer, a glass layer, a quartz glass layer, a mica layer, a tetrafluoroethylene plastic layer and a rubber layer.

Preferably, the thickness of the dielectric layer is 1 μm-10 mm.

Preferably, the potential difference between the electrode at the atomizing nozzle and the metal roller is 1-1000V.

Preferably, the ultrasonic atomization device is arranged at a position of 0.1 cm-3 cm below the water roller.

Preferably, the thickness of the water film on the water roller is 0.1-5 μm, and the contact angle is 10-45 degrees.

As shown in the attached drawings 1-6, the invention comprises a closed chain guide rail 1, a chain driving mechanism 2, a moving rod 3, an ultrasonic atomizer 4, a dampening water bin 5 and a metal roller 7, wherein the closed chain guide rail 1 is rectangular, the upper part of the closed chain guide rail 1 is an inwards concave circular arc-shaped spraying section, the closed chain guide rail 1 is respectively arranged at two ends of the metal roller 7, a moving chain is arranged in the closed chain guide rail 1, the chain driving mechanism 2 is connected with the moving chain and used for driving the moving chain to move in the closed chain guide rail 1, two ends of the moving rod 3 are respectively connected with the moving chain of the closed chain guide rail 1, the moving rod 3 is parallel to the metal roller 7, a closed spraying working belt is formed among a plurality of moving rods 3, the ultrasonic atomizer 4 is connected with the dampening water bin 5 to form an ultrasonic atomization device, the ultrasonic atomization device is arranged on the moving rod 3, and the ultrasonic atomizer 4 is located outside the spraying working band, the dampening water bin 5 is located inside the spraying working band, the metal roller 7 is an electrified roller, the outer surface of the metal roller 7 is covered with a dielectric layer 8, and the spraying end of the ultrasonic atomizer 4 is clamped with an electrode.

Preferably, the spray work belt is provided with a fountain water adding device, the fountain water adding device comprises a fountain water storage tank 10a, a water adding pipe 10b and a water adding head 10c, the water adding pipe 10b is provided with an electromagnetic valve, one end of the water adding pipe 10b is connected with the fountain water storage tank 10a, the other end of the water adding pipe is connected with the water adding head 10c, the bottom of the water adding head 10c is provided with two parallel sliding tables 10d, a water gap 10e is arranged between the sliding tables 10d, the bottom of the fountain water bin 5 is provided with a water adding port 5a, the water adding port 5a is internally provided with a movable pressing table 5b, the upper part of the movable pressing table 5b is provided with an inclined plane for sliding and pressing downwards, the bottom of the movable pressing table 5b is provided with a limiting sealing cover 5c, the limiting sealing cover 5c is positioned in the fountain water bin 5, the diameter of the limiting sealing cover 5c is larger than that of the water adding port 5a, one end of the reset spring 5d is connected with the bottom of the limit sealing cover 5c, and the other end is connected with the inner wall of the dampening water bin 5 opposite to the limit sealing cover 5 c.

Preferably, the metal roller 7 is negatively charged, and the water mist sprayed by the ultrasonic atomizer 4 is positively charged.

Preferably, the dielectric layer 8 is dielectric ceramic.

Preferably, the fountain further comprises a spring rod 5e, one end of the spring rod 5e is connected with the bottom of the limiting sealing cover 5c, the other end of the spring rod 5e is connected with the inner wall of the dampening water bin 5 opposite to the limiting sealing cover 5c, and the spring rod 5e is located around the reset spring 5d respectively.

Preferably, the upper parts of the two sides of the chain guide rail 1 are respectively provided with a proximity sensor 9, and the proximity sensors 9 correspond to ultrasonic atomization devices passing through the upper part of the spray section of the closed chain guide rail 1.

Preferably, the ultrasonic atomizer 4 is an ultrasonic atomizer 4 with a solenoid valve.

Preferably, the side of closed chain guide 1 be equipped with electrically conductive ware 11, carriage release lever 3 be tubular structure, the tip of carriage release lever 3 be connected with electrically conductive ware 11 through wiping line 12, carriage release lever 3 in be equipped with the cable that is used for connecting ultrasonic nebulizer 4, the cable is connected with wiping line 12 electricity, electrically conductive ware 11 be connected with power supply unit electricity, the power consumption of ultrasonic atomization in the removal process is realized to the mode of wiping power supply.

Preferably, still include electrified link joint 6, drive roll 13, tensioning roller 14, electrified link joint 6 wherein one section with the laminating of metal roll 7 tip mutually, make metal roll 7 electrified, drive roll 13 with electrified link joint 6 wherein one section laminating for drive electrified link joint 6, tensioning roller 14 with electrified link joint 6 wherein one section laminating for tensioning electrified link joint 6.

Preferably, the metal roller 7 is used to transfer dampening water to the printing plate roller.

Preferably, the metal roller 7 is a water transfer roller, a water distributing roller, a plate roller or a metering roller.

Preferably, the ultrasonic atomizer further comprises a control device and a control panel, wherein the control device is electrically connected with the chain driving mechanism 2, the ultrasonic atomizer 4, the electromagnetic valve of the water adding pipe 10b, the proximity sensor 9 and the power supply device respectively.

Preferably, the control device is a PLC controller or a single chip microcomputer.

Preferably, the control panel is provided with switches for controlling the chain drive mechanism 2 and the power supply device, respectively.

The application of the fountain water application method based on the combination of electrowetting and ultrasonic atomization is the application of the method in the lithography, and specifically comprises the following steps:

The working principle and the working process of the invention are as follows: the metal roller 7 is negatively charged under the action of the charged chain plate 6, and the electrode 3 positively charges the dampening water mist sprayed by the ultrasonic atomizer 4; in the rotating process of the metal roller 7, the closed chain guide rail 1 synchronously runs, and the ultrasonic atomization device moves along the closed chain guide rail 1 under the drive of the moving chain; when the ultrasonic atomization device passes through one of the proximity sensors 9, the ultrasonic atomization device passes through the spraying section of the closed chain guide rail 1, the control device controls the ultrasonic atomizer 4 of the ultrasonic atomization device to spray positive-charged dampening water mist to the surface of the metal roller 7, and meanwhile, the electro-wetting effect is generated under the action of positive electricity and negative electricity, so that the dampening water mist is attached to the surface of the dielectric layer 8 to form a water film; when the ultrasonic atomizer 4 continuously sprays, the ultrasonic atomizer 4 and the corresponding metal roller 7 area are relatively static in the same-speed moving process, so that the ultrasonic atomizer 4 continuously sprays the metal roller 7 area to form a water film with uniform and certain thickness; when the ultrasonic atomizer 4 moves close to the other proximity sensor 9 and is detected by the proximity sensor 9, the control means controls the ultrasonic atomizer 4 to stop spraying; a spraying working band formed by a plurality of moving rods 3 passing through the spraying section covers the surface of the metal roller 7;

in the moving process of the ultrasonic atomization device after the spraying section, after the ultrasonic atomization device is guided by the corner of the closed chain guide rail 1, the ultrasonic atomizer 4 faces downwards, and the dampening water bin 5 faces upwards; the dampening water bin 5 moves to a water adding head 10c of a dampening water adding device, the sliding table 10d presses down the inclined surface of the movable pressing table 5b in the moving process to enable the water adding port 5a to be opened, meanwhile, the control device controls the opening of an electromagnetic valve of the water adding pipe 10b, and dampening water in the dampening water storage tank 10a is filled into the dampening water bin 5 through the water adding pipe 10b, the water adding head 10c and the water adding port 5 a; after the ultrasonic atomization device moves through the water adding head 10c, under the action of a return spring 5d, the movable pressing table 5b returns, and the limiting sealing cover 5c seals the water adding port 5a, so that water adding of the dampening water bin 5 is completed; by analogy, each dampening water bin 5 passing through the water adding head 10c completes water adding; the spring rod 5e plays a role of supporting the movable pressing platform 5b, and prevents the movable pressing platform 5b from being inclined in the pressing process.

Example 1

A method of dampening water application based on a combination of electrowetting and ultrasonic atomization, comprising the steps of:

1) an ultrasonic atomization device is arranged below the water roller, dampening water is added into the ultrasonic atomization device, and an atomization nozzle of the ultrasonic atomization device is provided with an electrode; the dampening water is tap water; the ultrasonic atomization device is arranged at a position 0.1cm below the water roller;

2) the water roller comprises a metal roller and a dielectric layer covering the outer surface of the metal roller; starting an ultrasonic atomization device, and ultrasonically atomizing fountain water onto a water roller under the ultrasonic wave of 0.1 MHz; the dielectric layer is a ceramic layer; the thickness of the dielectric layer is 1 μmmm;

3) and electrifying the electrode at the atomizing nozzle and the metal rod at the same time, and starting the water roller to transfer the dampening water from the water roller to the printing plate in a continuous and uniform water film manner. The potential difference between the electrode at the atomizing nozzle and the metal roller is 1V. The thickness of the water film on the water roller is 5 mu m, and the contact angle is about 45 degrees.

The application of a fountain water application method based on the combination of electrowetting and ultrasonic atomization is applied to the lithography, and specifically comprises the following steps:

The content of alcohols and substitutes thereof in the dampening water used in the embodiment is 0, the printed matter is bright, clear in middle and dark, clear in level, clear in mesh points, accurate in angle, real, natural and harmonious in color, clean in layout and free of floating dirt. After the system of the embodiment is continuously operated for 6 months, the maintenance condition is not stopped, and the obtained printed matter can keep consistent quality.

Example 2

1) an ultrasonic atomization device is arranged below the water roller, dampening water is added into the ultrasonic atomization device, and an atomization nozzle of the ultrasonic atomization device is provided with an electrode; the dampening water is deionized water; the ultrasonic atomization device is arranged at the position 3cm below the water roller;

2) the water roller comprises a metal roller and a dielectric layer covering the outer surface of the metal roller; starting an ultrasonic atomization device, and ultrasonically atomizing fountain water onto a water roller under 100MHz ultrasonic waves; the dielectric layer is a glass layer; the thickness of the dielectric layer is 10 mm;

3) and electrifying the electrode at the atomizing nozzle and the metal rod at the same time, and starting the water roller to transfer the dampening water from the water roller to the printing plate in a continuous and uniform water film manner. The potential difference between the electrode at the atomizing nozzle and the metal roller is 1000V. The thickness of the water film on the water roller is 0.1 μm, and the contact angle is about 10 degrees.

The content of alcohols and substitutes thereof in the dampening water used in the embodiment is 0, the printed matter is bright, clear in middle and dark, clear in level, clear in mesh points, accurate in angle, real, natural and harmonious in color, clean in layout and free of floating dirt. After the system of the embodiment is continuously operated for 9 months, the maintenance condition is not stopped, and the obtained printed matter can keep consistent quality.

Example 3

1) an ultrasonic atomization device is arranged below the water roller, dampening water is added into the ultrasonic atomization device, and an atomization nozzle of the ultrasonic atomization device is provided with an electrode; the dampening water is distilled water; the ultrasonic atomization device is arranged at a position 0.5cm below the water roller;

2) the water roller comprises a metal roller and a dielectric layer covering the outer surface of the metal roller; starting an ultrasonic atomization device, and ultrasonically atomizing fountain water onto a water roller under the ultrasonic of 1 MHz; the dielectric layer is a ceramic layer, a glass layer, a quartz glass layer, a mica layer, a tetrafluoroethylene plastic layer and a rubber layer; the thickness of the dielectric layer is 5 μm;

3) and electrifying the electrode at the atomizing nozzle and the metal rod at the same time, and starting the water roller to transfer the dampening water from the water roller to the printing plate in a continuous and uniform water film manner. The potential difference between the electrode at the atomizing nozzle and the metal roller is 10V. The thickness of the water film on the water roller is 0.5 mu m, and the contact angle is about 45 degrees.

The content of alcohols and substitutes thereof in the dampening water used in the embodiment is 0, the printed matter is bright, clear in middle and dark, clear in level, clear in mesh points, accurate in angle, real, natural and harmonious in color, clean in layout and free of floating dirt. After the system of the embodiment is continuously operated for 12 months, the maintenance condition is not stopped, and the obtained printed matter can keep consistent quality.

Example 4

1) an ultrasonic atomization device is arranged below the water roller, dampening water is added into the ultrasonic atomization device, and an atomization nozzle of the ultrasonic atomization device is provided with an electrode; the dampening water is added with 30% of the original surface active substance; the ultrasonic atomization device is arranged at a position 1cm below the water roller;

2) the water roller comprises a metal roller and a dielectric layer covering the outer surface of the metal roller; starting an ultrasonic atomization device, and ultrasonically atomizing fountain water onto a water roller under 2MHz ultrasonic; the dielectric layer is a quartz glass layer; the thickness of the dielectric layer is 10 μm;

3) and electrifying the electrode at the atomizing nozzle and the metal rod at the same time, and starting the water roller to transfer the dampening water from the water roller to the printing plate in a continuous and uniform water film manner. The potential difference between the electrode at the atomizing nozzle and the metal roller is 10V. The thickness of the water film on the water roller is 1 mu m, and the contact angle is about 40 degrees.

The printed matter of the embodiment has the advantages of bright, medium and dark tones, clear layers, clear dots, accurate angles, real, natural and harmonious colors, clean layout and no floating dirt phenomenon. After the system of the embodiment is continuously operated for 24 months, the maintenance condition is not stopped, and the obtained printed matter can keep consistent quality.

Example 5

1) an ultrasonic atomization device is arranged below the water roller, dampening water is added into the ultrasonic atomization device, and an atomization nozzle of the ultrasonic atomization device is provided with an electrode; the dampening water is added with surface active substances with the original addition amount of 15%; (ii) a The ultrasonic atomization device is arranged 2cm below the water roller;

2) the water roller comprises a metal roller and a dielectric layer covering the outer surface of the metal roller; starting an ultrasonic atomization device, and ultrasonically atomizing fountain water onto a water roller under the ultrasonic of 10 MHz; the dielectric layer is a mica layer; the thickness of the dielectric layer is 100 μm;

3) and electrifying the electrode at the atomizing nozzle and the metal rod at the same time, and starting the water roller to transfer the dampening water from the water roller to the printing plate in a continuous and uniform water film manner. The potential difference between the electrode at the atomizing nozzle and the metal roller is 100V. The thickness of the water film on the water roller is 3 mu m, and the contact angle is about 20 degrees.

The printed matter of the embodiment has the advantages of bright, medium and dark tones, clear layers, clear dots, accurate angles, real, natural and harmonious colors, clean layout and no floating dirt phenomenon. After the system of the embodiment is continuously operated for 36 months, the maintenance condition is not stopped, and the obtained printed matter can keep consistent quality.

Example 6

1) an ultrasonic atomization device is arranged below the water roller, dampening water is added into the ultrasonic atomization device, and an atomization nozzle of the ultrasonic atomization device is provided with an electrode; the dampening water is added with 20% of the original addition amount of surface active substances; (ii) a The ultrasonic atomization device is arranged at a position 0.8cm below the water roller;

2) the water roller comprises a metal roller and a dielectric layer covering the outer surface of the metal roller; starting an ultrasonic atomization device, and ultrasonically atomizing fountain water onto a water roller under the ultrasonic wave of 1.5 MHz; the dielectric layer is a ceramic layer, a glass layer, a quartz glass layer, a mica layer, a tetrafluoroethylene plastic layer and a rubber layer; the thickness of the dielectric layer is 1 mm;

3) and electrifying the electrode at the atomizing nozzle and the metal rod at the same time, and starting the water roller to transfer the dampening water from the water roller to the printing plate in a continuous and uniform water film manner. The potential difference between the electrode at the atomizing nozzle and the metal roller is 50V. The thickness of the water film on the water roller is 2.5 mu m, and the contact angle is about 25 degrees.

The printed matter of the embodiment has the advantages of bright, medium and dark tones, clear layers, clear dots, accurate angles, real, natural and harmonious colors, clean layout and no floating dirt phenomenon. After the system of the embodiment is continuously operated for 15 months, the maintenance condition is not stopped, and the obtained printed matter can keep consistent quality.

Example 7

1) an ultrasonic atomization device is arranged below the water roller, dampening water is added into the ultrasonic atomization device, and an atomization nozzle of the ultrasonic atomization device is provided with an electrode; the dampening water is tap water; the ultrasonic atomization device is arranged at a position 1.5cm below the water roller;

2) the water roller comprises a metal roller and a dielectric layer covering the outer surface of the metal roller; starting an ultrasonic atomization device, and ultrasonically atomizing fountain water onto a water roller under 5MHz ultrasonic wave; the dielectric layer is a ceramic layer and a quartz glass layer; the thickness of the dielectric layer is 20 μm, wherein the ceramic layer and the quartz glass layer are respectively 10 μm thick;

3) and electrifying the electrode at the atomizing nozzle and the metal rod at the same time, and starting the water roller to transfer the dampening water from the water roller to the printing plate in a continuous and uniform water film manner. The potential difference between the electrode at the atomizing nozzle and the metal roller is 500V. The thickness of the water film on the water roller is 1.5 mu m, and the contact angle is about 30 degrees.

The content of alcohols and substitutes thereof in the dampening water used in the embodiment is 0, the printed matter is bright, clear in middle and dark, clear in level, clear in mesh points, accurate in angle, real, natural and harmonious in color, clean in layout and free of floating dirt. After the system of the embodiment is continuously operated for 18 months, the maintenance condition is not stopped, and the obtained printed matter can keep consistent quality.

Claims

1. A method for applying dampening water based on a combination of electrowetting and ultrasonic atomization, characterized by the steps of:

3) electrifying the electrode and the metal rod at the atomizing nozzle at the same time, and starting the water roller to transfer dampening water from the water roller to the printing plate in a continuous and uniform water film manner;

the dampening water applying system based on electrowetting and ultrasonic atomization combination comprises a closed chain guide rail (1), a chain driving mechanism (2), a moving rod (3), an ultrasonic atomizer (4), a dampening water bin (5) and a metal roller (7), wherein the closed chain guide rail (1) is rectangular, the upper part of the closed chain guide rail (1) is an inwards concave arc-shaped spraying section, the closed chain guide rail (1) is respectively arranged at two ends of the metal roller (7), a moving chain is arranged in the closed chain guide rail (1), the chain driving mechanism (2) is connected with the moving chain and used for driving the moving chain to move in the closed chain guide rail (1), two ends of the moving rod (3) are respectively connected with the moving chain of the closed chain guide rail (1), and the moving rod (3) is parallel to the metal roller (7), constitute closed spraying work area between a plurality of carriage release levers (3), ultrasonic atomization ware (4) be connected with dampening sump (5), constitute ultrasonic atomization device, ultrasonic atomization device locates carriage release lever (3), and ultrasonic atomization ware (4) are located outside the spraying work area, dampening sump (5) are located spraying work area within, metal roller (7) be electrified roller, metal roller (7) surface cover have dielectric layer (8), ultrasonic atomization ware (4) spraying end centre gripping have the electrode.

2. The method of claim 1, wherein the dampening water is any one of tap water, deionized water, distilled water, and existing dampening water with any amount of surface active substances added.

3. The method of claim 1, wherein the dielectric layer is any one or more of a ceramic layer, a glass layer, a quartz glass layer, a mica layer, a tetrafluoroethylene plastic layer, and a rubber layer.

4. The method of claim 1, wherein the potential difference between the electrode at the atomizing nozzle and the metal roller is 1-1000V.

5. The method of claim 1, wherein the thickness of the water film on the water roller is 0.1-5 μm and the contact angle is 10-45 °.

6. The dampening water applying method based on the combination of electrowetting and ultrasonic atomization according to claim 1, characterized in that a dampening water adding device is arranged in the spray work band, the dampening water adding device comprises a dampening water storage tank (10 a), a water adding pipe (10 b) and a water adding head (10 c), the water adding pipe (10 b) is provided with an electromagnetic valve, one end of the water adding pipe (10 b) is connected with the dampening water storage tank (10 a), the other end of the water adding pipe is connected with the water adding head (10 c), two parallel sliding tables (10 d) are arranged at the bottom of the water adding head (10 c), a water gap (10 e) is arranged between the sliding tables (10 d), a water adding port (5 a) is arranged at the bottom of the dampening water sump (5), a movable pressing table (5 b) is arranged in the water adding port (5 a), an inclined plane for sliding and pressing is arranged at the upper part of the movable pressing table (5 b), a limit sealing cover (5 c) is arranged at the bottom of the movable pressing table (5 b), spacing sealed lid (5 c) are located dampening sump (5), and the diameter of spacing sealed lid (5 c) is greater than the diameter of filler (5 a), dampening sump (5) in be equipped with reset spring (5 d), the one end and the bottom of spacing sealed lid (5 c) of reset spring (5 d) are connected, the other end and the relative dampening sump (5) inner wall connection of spacing sealed lid (5 c).

7. The method for applying dampening water based on the combination of electrowetting and ultrasonic atomization according to claim 1, characterized in that a conductive device (11) is arranged on the side surface of the closed chain guide (1), the movable rod (3) is of a tubular structure, the end of the movable rod (3) is connected with the conductive device (11) through a trolley wire (12), a cable for connecting the ultrasonic atomizer (4) is arranged in the movable rod (3), the cable is electrically connected with the trolley wire (12), and the conductive device (11) is electrically connected with a power supply device.

8. The dampening water application method based on the combination of electrowetting and ultrasonic atomization according to claim 1, characterized by further comprising a charging chain plate (6), a driving roller (13) and a tensioning roller (14), wherein a section of the charging chain plate (6) is attached to an end of the metal roller (7) to charge the metal roller (7), the driving roller (13) is attached to a section of the charging chain plate (6) to drive the charging chain plate (6), and the tensioning roller (14) is attached to a section of the charging chain plate (6) to tension the charging chain plate (6).

9. Use of a method according to any of claims 1 to 5 for applying dampening water based on electrowetting in combination with ultrasonic atomization, in lithography, comprising the following steps: