KR102608210B1 - A method and apparatus for controlling a slot die coater based on a continuous roll-to-roll process - Google Patents

Abstract

A slot die coater control device based on a roll-to-roll continuous process according to an embodiment of the present invention is a slot die including a nozzle-shaped coating liquid discharge unit that provides a coating liquid to the upper part of a flexible substrate in a roll-to-roll continuous process. A main body including a slot-die and a back up roll that moves the flexible substrate through a rotational motion, is connected to the main body, and controls the spreadability of the coating liquid by applying voltage to the slot die. It is characterized in that it includes a voltage supply module.

Description

{A method and apparatus for controlling a slot die coater based on a continuous roll-to-roll process}

The present invention relates to a slot die coater control method and device based on a roll-to-roll continuous process, and more specifically, to improve coating stability by controlling the surface properties between the material and the coating solution during the slot die coating process of forming a coating layer on a substrate. Pertains to a slot die coater control method and device.

Roll-to-roll continuous process for mass, high-speed production is one of the processes that has recently been attracting attention. The roll-to-roll continuous process may correspond to a process of producing a functional film through coating and printing on a flexible film using tension as a traction force.

Coating methods for forming a uniform thin film of a functional film may include gravure, blade, spray, slot-die coating, etc. Here, the slot-die coating method may correspond to a method of forming a thin film of a certain thickness by supplying fluid through a pump between two precision-machined dies. In particular, the slot-die coating method is suitable for forming a thin film with high uniformity and can have the advantage of forming a predictable thin film thickness by appropriately setting various process conditions.

Recently, the scope of application of the slot-die coating method is gradually expanding to industrial fields such as thin film optical films, liquid crystal displays, organic solar cells, and touch screens.

Korean Patent No. 10-1860086 discloses that a slot die device with a coating bar for adjusting the coating thickness is provided with a main body, a coating liquid supply line provided inside the main body, and a coating liquid supplied from the coating liquid supply line across the left and right sides of the main body. The cavity that receives the supply, the slot portion provided inside the main body and forming the external discharge path of the coating liquid contained in the cavity, and the outer end of the slot portion of the main body are detachable so that the coating thickness can be adjusted by changing the volume of the coating liquid. Includes a coating bar that is installed properly.

Korean Patent No. 10-1860086 (2018.05.15)

One embodiment of the present invention controls the surface characteristics between the substrate and the coating solution by applying voltage into the coating solution through a voltage supply module mounted on the slot die coater, thereby changing the spreadability of the coating solution and stability of the coating performance of the coating solution during high-speed operation. The aim is to provide a slot die coater control method and device based on a roll-to-roll continuous process that improves.

A slot die coater control device based on a roll-to-roll continuous process according to an embodiment of the present invention is a slot die including a nozzle-shaped coating liquid discharge unit that provides a coating liquid to the upper part of a flexible substrate in a roll-to-roll continuous process. A main body including a slot-die and a back up roll that moves the flexible substrate through a rotational motion, is connected to the main body, and controls the spreadability of the coating liquid by applying voltage to the slot die. It is characterized in that it includes a voltage supply module.

The voltage supply module includes a voltage input terminal and a ground terminal, the voltage input terminal is connected to one side of the slot die, and the ground terminal is connected to a backup roll.

The voltage supply module includes a substrate movement speed measuring unit that measures the web speed of the flexible substrate passing between the slot die and the backup roll at regular intervals, and an on/off switch. A power supply unit that controls the operation of the voltage supply module, a voltage application unit that receives power from the power supply unit and applies voltage to the slot die of the main body to control the spreadability of the coating liquid, and the intensity of the voltage applied from the voltage application unit. It includes a voltage regulator that adjusts to increase or decrease the contact angle between the coating liquid and the flexible substrate.

The substrate movement speed measuring unit blocks the power supply to the voltage supply module by keeping the switch in the off state when the moving speed of the flexible substrate is less than a preset value, and when the moving speed of the flexible substrate is more than a preset value, Turn the switch to the on state to supply power to the voltage supply module.

The voltage regulator can control the voltage in one method selected from a DC mode that applies the same voltage for a certain period of time or a pulse mode that applies a changed voltage at regular intervals. You can.

The coating solution may use conductive ink to improve spreadability by electromagnetic force, and the conductive ink includes conductive nanoparticles containing Ag.

The voltage supply module further includes an electric leakage prevention unit using PEEK (PolyEtherEtherKetone) resin, and the electric leakage prevention unit can check whether an electric leakage occurs and prevent an electric leakage when the voltage exceeds a certain level.

A slot die coater control method based on a roll-to-roll continuous process according to an embodiment of the present invention includes supplying a coating liquid through a coating liquid discharge portion of a slot die, and applying the coating liquid on a flexible substrate passing between the slot die and a backup roll. controlling the spreadability of the coating liquid by applying voltage to the slot die through a voltage supply module, and adjusting the intensity of the voltage applied from the voltage supply module to adjust the contact angle between the coating liquid and the flexible substrate. It is characterized by comprising the step of increasing or decreasing.

Before applying voltage to the slot die, the moving speed of the flexible substrate may be measured, and if the moving speed is less than a preset value, power supply to the voltage supply module may be blocked.

The step of adjusting the intensity of the voltage is one of a DC mode that applies the same voltage for a certain period of time or a pulse mode that applies a changed voltage at regular intervals. The voltage can be adjusted in this way.

The disclosed technology can have the following effects. However, since it does not mean that a specific embodiment must include all of the following effects or only the following effects, the scope of rights of the disclosed technology should not be understood as being limited thereby.

The slot die coater control method and device based on the roll-to-roll continuous process according to an embodiment of the present invention controls the surface characteristics between the substrate and the coating solution by applying voltage to the coating solution through a voltage supply module mounted on the slot die coater. The effect of improving the spreadability of the liquid and the stability of the coating performance of the coating liquid during high-speed operation can be obtained.

1 is a diagram for explaining a slot die coater according to an embodiment of the present invention.
Figure 2 is a block diagram for explaining the voltage supply module of Figure 1.
FIG. 3 is a diagram illustrating the voltage regulation mode of the voltage regulator of FIG. 2.
4 and 5 are diagrams for explaining a slot die coater according to an embodiment of the present invention.
Figure 6 is a flowchart illustrating a slot die coater control method based on a roll-to-roll continuous process according to an embodiment of the present invention.
Figure 7 is a diagram for explaining the electrowetting phenomenon according to an embodiment of the present invention.
Figure 8 is a diagram for explaining the correlation between the contact angle between the substrate and the coating solution and the thickness of the coating solution.
Figures 9 and 10 are views for explaining the difference in thickness uniformity of the coating layer depending on whether electromagnetic force is applied.
Figures 11 and 12 are diagrams for explaining the spreadability of the coating liquid according to the moving speed of the flexible substrate and the strength of the voltage.

Since the description of the present invention is only an example for structural or functional explanation, the scope of the present invention should not be construed as limited by the examples described in the text. In other words, since the embodiments can be modified in various ways and can have various forms, the scope of rights of the present invention should be understood to include equivalents that can realize the technical idea. In addition, the purpose or effect presented in the present invention does not mean that a specific embodiment must include all or only such effects, so the scope of the present invention should not be understood as limited thereby.

Meanwhile, the meaning of the terms described in this application should be understood as follows.

Terms such as “first” and “second” are used to distinguish one component from another component, and the scope of rights should not be limited by these terms. For example, a first component may be named a second component, and similarly, the second component may also be named a first component.

When a component is referred to as being “connected” to another component, it should be understood that it may be directly connected to the other component, but that other components may exist in between. On the other hand, when a component is referred to as being “directly connected” to another component, it should be understood that there are no other components in between. Meanwhile, other expressions that describe the relationship between components, such as "between" and "immediately between" or "neighboring" and "directly neighboring" should be interpreted similarly.

Singular expressions should be understood to include plural expressions unless the context clearly indicates otherwise, and terms such as “comprise” or “have” refer to implemented features, numbers, steps, operations, components, parts, or them. It is intended to specify the existence of a combination, and should be understood as not excluding in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

For each step, identification codes (e.g., a, b, c, etc.) are used for convenience of explanation. The identification codes do not explain the order of each step, and each step clearly follows a specific order in context. Unless specified, events may occur differently from the specified order. That is, each step may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the opposite order.

The present invention can be implemented as computer-readable code on a computer-readable recording medium, and the computer-readable recording medium includes all types of recording devices that store data that can be read by a computer system. . Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage devices. Additionally, the computer-readable recording medium can be distributed across computer systems connected to a network, so that computer-readable code can be stored and executed in a distributed manner.

All terms used herein, unless otherwise defined, have the same meaning as commonly understood by a person of ordinary skill in the field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as consistent with the meaning they have in the context of the related technology, and cannot be interpreted as having an ideal or excessively formal meaning unless clearly defined in the present application.

1 is a diagram for explaining a slot die coater according to an embodiment of the present invention.

Referring to FIG. 1, the slot die coater 100 according to an embodiment of the present invention may include a main body 110 and a voltage supply module 120.

The main body 110 may be composed of a slot die 110a and a back up roll 110b. The main body 110 supplies the coating liquid between nozzle-shaped fine metal plates called slot dies 110a, and supplies the coating liquid onto a flexible substrate passing between the backup rolls 110b located below the slot die 110a. Apply. More specifically, the operation of forming a coating layer can be performed by uniformly applying a coating liquid to the surface of a flexible substrate moving in a direction perpendicular to the direction of movement of the slot die 110a.

The voltage supply module 120 is connected to the main body 110 and can perform an operation of applying voltage to the slot die 110a of the main body 110. The voltage supply module 120 is based on Electro Hydro Dynamic (EHD), which can apply electromagnetic force to the slot die coater, and applies voltage to the main body 110 to connect the slot die 110a and the backup roll. The spreadability of the coating liquid applied to the surface of the flexible substrate passing between (110b) can be controlled.

FIG. 2 is a block diagram for explaining the voltage supply module of FIG. 1.

Referring to FIG. 2 , the voltage supply module 200 may include a substrate movement speed measurement unit 210, a power supply unit 220, a voltage application unit 230, and a voltage regulator 240.

First, the substrate movement speed measuring unit 210 measures the movement speed (web speed) of the flexible substrate passing between the slot die and the backup roll at a certain period. Depending on the speed at which the flexible substrate moves, there is a difference in the stability of the coating layer applied to the substrate. Accordingly, it is possible to determine whether to operate the voltage supply module based on the moving speed of the flexible substrate. For example, when the moving speed of the flexible substrate measured by the substrate moving speed measuring unit 210 is greater than or equal to a preset moving speed value, voltage can be applied to the main body of the slit die coater by driving the power of the voltage supply module 200. .

The power supply unit 220 can control the operation of the voltage supply module 200 through an on/off switch. For example, if the moving speed of the substrate measured through the substrate moving speed measuring unit 210 is less than a preset value, it is determined that voltage supply to the main body is not necessary, and the switch is kept in the off state to maintain the voltage supply module ( 200) and cut off the power supply.

On the contrary, if the moving speed of the substrate measured through the substrate moving speed measuring unit 210 is greater than the preset value, it is determined that voltage is needed to be supplied to the main body, and the switch is converted to the on state to supply the voltage supply module 200. Supply power.

The voltage application unit 230 receives power from the power unit 220 and applies voltage to the slot die of the main body 110 to control the spreadability of the coating liquid.

The voltage control unit 240 can increase or decrease the contact angle between the coating liquid and the flexible substrate by adjusting the intensity of the voltage applied from the voltage application unit 230, and can adjust the voltage by applying various voltage control modes.

The voltage supply module may further include an earth leakage prevention unit. The earth leakage prevention unit is made of PEEK (PolyEtherEtherKetone) resin, and the earth leakage prevention unit can check whether an earth leakage has occurred and prevent the earth leakage when the voltage exceeds a certain level.

FIG. 3 is a diagram explaining the voltage regulation mode of the voltage regulator of FIG. 2.

FIG. 3A is a graph showing a DC mode that uses the same voltage for a certain period of time. And, Figure 3b is a graph showing a pulse mode in which a changed voltage is applied at regular periodic intervals.

The voltage regulator can control the voltage in either DC mode or pulse mode, but it is not necessarily limited to this and the voltage control method can be changed and applied depending on the situation.

4 and 5 are diagrams for explaining a slot die coater according to an embodiment of the present invention.

Referring to FIGS. 4 and 5 , the slot die coater 400 according to an embodiment of the present invention may include a slot die 410, a backup roll 420, and a voltage supply module 430.

The slot die 410 consists of two precision-machined slot dies 410 arranged at regular intervals, and is provided with a coating liquid discharge part 413 that discharges a coating liquid between the slot dies 410. . The coating liquid discharge portion 413 may be formed in the form of a line extending along the long axis direction of the slot die 410. An insulating frame 415 made of an insulating material may be further included on the slot die 410.

The backup roll 420 is located below the slot die 410, and the flexible substrate 440 passes between the slot die 410 and the backup roll 420. The flexible substrate 440 is moved in a direction perpendicular to the moving direction of the slot die 410 by the rotational movement of the backup roll 420.

The voltage supply module 450 may control the spreadability of the coating liquid applied to the flexible substrate 440 by applying voltage to the coating liquid discharge portion 413 of the slot die 410. The voltage supply module 450 includes a voltage input terminal and a ground terminal. The voltage input terminal (A) is connected to one side of the slot die 410 (see FIG. 5), and the ground terminal is connected to the backup roll 420. connected to

The slot die coater 400 is configured such that when the coating liquid is supplied through the coating liquid discharge unit 413 between the slot dies 410, the coating layer 445 is formed between the coating liquid discharge unit 413 and the flexible substrate 440. This can be coated. At this time, when voltage is applied to the slot die 410 through the power supply module 450, the surface tension between the coating liquid and the flexible substrate is reduced due to an electrowetting phenomenon, and this changes the contact angle between the coating liquid and the flexible substrate. . This change in contact angle improves the spreadability of the coating solution and reduces the thickness of the coating layer, enabling ultra-thin coating with increased stability. Here, conductive ink can be used to maximize the effect of improving the spreadability of the coating liquid by electromagnetic force. For example, a coating solution of conductive nanoparticles containing Ag can be used, but the type of coating solution is not necessarily limited thereto.

Figure 6 is a flowchart for explaining a slot die coater control method based on a roll-to-roll continuous process according to an embodiment of the present invention.

First, the step of supplying the coating liquid through the coating liquid discharge part of the slot die is performed (step S600).

Next, the step of applying the coating liquid on the flexible substrate passing between the slot die and the backup roll is performed (step S610). At this time, the moving speed of the flexible substrate can be measured, and if the moving speed is less than a preset value, the power supply to the voltage supply module can be blocked. Figure 6 shows only the case of supplying power to the voltage supply module, but whether or not the voltage supply module operates can be determined depending on the moving speed of the flexible substrate.

Afterwards, the step of controlling the spreadability of the coating liquid is performed by applying voltage to the slot die through the voltage supply module (step S620).

Next, the intensity of the voltage applied from the voltage supply module can be adjusted to increase or decrease the contact angle between the coating liquid and the flexible substrate (step S630).

Figure 7 is a diagram for explaining the electrowetting phenomenon according to an embodiment of the present invention.

Referring to FIG. 7, FIG. 7(i) shows the shape of the coating liquid 710 when no voltage is applied after the coating liquid droplet is formed on the top of the substrate 700, and FIG. 7(ii) shows the shape of the coating liquid 710 when no voltage is applied. ) This shows the change in the coating liquid 710 when voltage is applied after the coating liquid droplet is formed at the top.

The electrowetting phenomenon occurs when a voltage is applied after the coating liquid droplet is formed, a potential difference occurs due to the movement of charges within the coating liquid 710, and the contact angle between the substrate 700 and the coating liquid 710 changes as shown in FIG. 7(ii). A phenomenon occurs. That is, it can be seen that when voltage is applied after forming the coating liquid 710, the contact angle between the substrate 700 and the coating liquid 710 decreases, thereby improving the spreadability of the coating liquid 710.

Figure 8 is a diagram for explaining the correlation between the contact angle between the substrate and the coating solution and the thickness of the coating solution.

Referring to FIG. 8, a contact angle (θ) may be formed according to the relationship between the surface energy of the substrate and the surface tension of the coating liquid. Tension applied to the substrate can change the surface energy of the substrate, which can also affect the degree of spread of the coating liquid in contact with the substrate. Accordingly, a change may occur in the contact angle at the point where the surface of the substrate and the surface of the coating liquid come into contact. The relationship between contact angle and surface energy can be expressed as the following [Equation 1] and [Equation 2], where [Equation 1] represents a state in which the coating liquid is not spread, and [Equation 2] represents a state in which the coating liquid is widely spread. indicates. Here, γ _s represents the solid (substrate) surface energy, γ _l represents the liquid (coating liquid) surface energy, and γ _sl represents the solid and liquid surface energies.

[Equation 1]

[Equation 2]

In addition, the thickness of the coating solution is affected by the contact angle between the substrate and the coating solution, and as the contact angle decreases, the spreadability increases and the thickness of the coating layer decreases.

Assuming that the volume of the coating liquid in the ideal state (ψ _ideal ) and the volume of the coating liquid in the spreading state (ψ _widening ) are the same, the thickness of the coating liquid is determined by the flow rate of the coating liquid and the width of the coated liquid. layer), the moving speed of the substrate (web speed), and the contact angle between the substrate and the coating solution. Additionally, the thickness of the coating liquid can be expressed as equation 3 below. Here, Th is the thickness of the coating liquid in a spreading state, Th' is the thickness of the coating liquid in an ideal state, and k is the thickness determination constant.

[Equation 3]

Figures 9 and 10 are diagrams to explain the difference in thickness uniformity of the coating layer depending on whether electromagnetic force is applied. Figures 9 and 10 show the coating liquid discharge form of a slot die coater without electromagnetic force applied and a slot die coater with electromagnetic force applied, respectively.

First, referring to FIG. 9, the discharged coating liquid 910 has a non-uniform velocity profile due to the velocity gradient of the coating liquid 910 caused by the internal wall condition of the slot die coater 900 (see FIG. 9A). For example, because the speed of the coating liquid discharged from the center of the coating liquid discharge unit is faster than the speed of the coating liquid discharged from the outer part of the coating liquid discharge unit, the coating stability of the coating layer is reduced. Accordingly, when the operating speed is continuously increased at the same flow rate, a coating layer 920 having a strip shape as shown in FIG. 9B is formed according to the law of mass conservation.

Meanwhile, referring to FIG. 10, when electromagnetic force is applied to the slot die coater 900, the coating liquid 910 discharged from the outer portion of the coating liquid discharge unit has an inclination due to electrical stress, and is tilted from the outside of the slot die coater 900. By removing the velocity gradient, the coating liquid 910 has a uniform velocity profile in the width direction, as shown in FIG. 10A.

Accordingly, the spreadability of the coating liquid at the same flow rate is improved, thereby ensuring coating stability and forming a coating layer 920 of uniform thickness as shown in FIG. 10b.

Figures 11 and 12 are diagrams for explaining the spreadability of the coating liquid according to the moving speed of the flexible substrate and the strength of the voltage.

Referring to Figures 11 and 12, a number of cases in which the moving speed (web speed) and voltage strength of the flexible substrate were different were compared and analyzed.

When the moving speed is low, as in case 1, it is possible to form a uniform coating layer without applying voltage. However, when the moving speed increased as in case 2, the coating bead was not fully developed in the width direction, and it can be seen that the coating layer was formed in a strip shape.

Accordingly, it can be seen that when a certain voltage is applied as in case 3, the coating bead develops in the width direction and the coating properties are improved. At this time, as in Case 4 and Case 5, it can be seen that when the intensity of the voltage is increased, the spreadability of the coating liquid is improved and a uniform coating layer is formed. In other words, it can be seen that as the intensity of voltage increases, the spreadability of the coating layer improves. However, if a voltage outside a certain range is applied, high voltage sparks occur between the slot die coater and the backup roll. Therefore, when applying voltage, it is desirable to adjust the voltage within the range of 0 to 3V, and more preferably within the range of 1 to 2.8V.

As described above, the slot die coater according to the present invention is equipped with an EHD (Electro Hydro Dynamic)-based voltage supply module capable of applying electromagnetic force, thereby ensuring coating stability and achieving the effect of forming an ultra-thin coating. More specifically, coating instability that occurs during high-speed driving can be resolved by improving the spreadability of the coating liquid by electromagnetic force applied through an EHD-based voltage supply module. In addition, the effect of forming a uniform velocity profile in the width direction can be obtained by removing the velocity gradient outside the slot die coater through jet injection using electromagnetic force applied through the voltage supply module.

Although the present invention has been described above with reference to preferred embodiments, those skilled in the art may make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that you can do it.

National research and development project that supported this invention

[Task name] Development of smart printing electronic manufacturing technology for mass production of large-area, high-efficiency functional films

[Management agency] Ministry of Science and ICT

[Assignment number] 2020R1A2C1012428

[Task Name] R2R Printing Flexible Computer Development Research Center

[Management agency] Ministry of Science and ICT

[Assignment number] 2020R1A5A1019649

100, 900: Slot die coater 110: Main body
110a, 410: Slot die 110b, 420: Backup roll
120, 200, 450: voltage supply module 210: substrate movement speed measurement unit
220: power supply unit 230: voltage application unit
240: Voltage control unit 413: Coating liquid discharge unit
420: Insulating frame 440: Flexible substrate
445, 920: Coating layer 700: Substrate
710, 910: Coating liquid

Claims (10)

In a roll-to-roll continuous process, a slot die includes a nozzle-shaped coating liquid discharge portion that provides coating liquid to the upper part of the flexible substrate, and a backup roll (back) that moves the flexible substrate through a rotational motion. main body including up roll; and
It includes a voltage supply module connected to the main body and controlling the spreadability of the coating liquid by applying voltage to the slot die,
The voltage supply module is
A substrate movement speed measuring unit that measures the web speed of the flexible substrate passing between the slot die and the backup roll at regular intervals;
a power supply unit that regulates the operation of the voltage supply module through an on/off switch according to the moving speed;
a voltage application unit that receives power from the power unit and applies voltage to the slot die of the main body unit to control the spreadability of the coating liquid; and
It includes a voltage regulator that adjusts the intensity of the voltage applied from the voltage applicator to increase or decrease the contact angle between the coating liquid and the flexible substrate,
The substrate movement speed measuring unit blocks the power supply to the voltage supply module by keeping the switch in the off state when the moving speed of the flexible substrate is less than a preset value, and when the moving speed of the flexible substrate is more than a preset value, A slot die coater control device based on a roll-to-roll continuous process, characterized in that it supplies power to the voltage supply module by converting the switch to the on state.
The method of claim 1, wherein the voltage supply module
A slot die coater control device based on a roll-to-roll continuous process, comprising a voltage input terminal and a ground terminal, wherein the voltage input terminal is connected to one side of the slot die, and the ground terminal is connected to a backup roll.
delete delete The method of claim 1, wherein the voltage regulator
Characterized by controlling the voltage in one of two ways: DC mode, which applies the same voltage for a certain period of time, or pulse mode, which applies a changed voltage at regular intervals. A slot die coater control device based on a roll-to-roll continuous process.
The method of claim 1, wherein the coating solution is
Conductive ink can be used to improve spreadability by electromagnetic force, and the conductive ink is a slot die coater control device based on a roll-to-roll continuous process, characterized in that it contains conductive nanoparticles including Ag.
The method of claim 1, wherein the voltage supply module
A slot die coater control device based on a roll-to-roll continuous process, further comprising an electric leakage prevention unit using PEEK (PolyEtherEtherKetone) resin, wherein the earth leakage prevention unit checks whether an electric leakage occurs and prevents an electric leakage when a certain voltage is exceeded.
Supplying a coating liquid through a coating liquid discharge portion of a slot die included in the main body;
Applying a coating liquid on a flexible substrate passing between the slot die and the backup roll;
controlling the spreadability of the coating liquid by applying voltage to the slot die through a voltage supply module connected to the main body; and
Comprising: increasing or decreasing the contact angle between the coating liquid and the flexible substrate by adjusting the intensity of the voltage applied from the voltage supply module,
The voltage supply module is
A substrate movement speed measuring unit that measures the web speed of the flexible substrate passing between the slot die and the backup roll at regular intervals;
a power supply unit that regulates the operation of the voltage supply module through an on/off switch according to the moving speed;
a voltage application unit that receives power from the power unit and applies voltage to the slot die of the main body unit to control the spreadability of the coating liquid; and
It includes a voltage regulator that adjusts the intensity of the voltage applied from the voltage applicator to increase or decrease the contact angle between the coating liquid and the flexible substrate,
Before applying voltage to the slot die, the moving speed of the flexible substrate is measured, and if the moving speed is less than a preset value, the power supply to the voltage supply module is cut off, and if the moving speed is more than a preset value, the power supply to the voltage supply module is measured. In this case, a slot die coater control method based on a roll-to-roll continuous process, characterized in that supplying power to the voltage supply module.
delete The method of claim 8, wherein the step of adjusting the intensity of the voltage is
Characterized by controlling the voltage in one of two ways: DC mode, which applies the same voltage for a certain period of time, or pulse mode, which applies a changed voltage at regular intervals. A slot die coater control method based on a roll-to-roll continuous process.