Transfer type coating system and coating control method and coating equipment thereof

Abstract

The invention relates to the technical field of coating, in particular to a transfer type coating system, a coating control method of the transfer type coating system and coating equipment. The transfer type coating system collects the edge thickness of a slurry coating on line and controls an angular position control mechanism to rotate so as to adjust the feeding angle according to the difference value between the edge thickness of the slurry coating and a preset thickness range; the shearing force at the outlet of the scraper is accurately adjusted by adjusting the feeding angle, and the viscosity of the slurry is adjusted by changing the shearing force, so that the coating thickness is adjusted; through a shearing force regulation and control mechanism, the problems of slurry accumulation, thinning, coating missing and the like at the coating edge are effectively inhibited, so that the thickness uniformity of the coating edge is improved; by utilizing the shear thinning characteristic of the non-Newtonian fluid, the viscosity of the slurry is controllable in spatial distribution, the coating stability of an edge area is improved, the edge thickness is regulated and controlled in real time through online closed-loop feedback, the consistency of the whole coating is remarkably improved, the reworking rate and the reject ratio are reduced, and the method is suitable for coating processes of various slurry systems.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coating, in particular to a transfer coating system, a coating control method thereof and a coating device. BACKGROUND

[0002] In the field of precision manufacturing such as lithium ion batteries, sodium ion batteries and optical films, the transfer coating process is widely used. The process usually uniformly distributes the fluid from the trough to the surface of the transfer roller by the comma doctor blade, and then the transfer roller extrudes the coating material to the surface of the substrate. In order to ensure the uniformity of the coating thickness, the existing process is controlled in the following ways: Fixed doctor blade structure and coating gap control: set the physical distance between the doctor blade and the transfer roller to control the thickness of the slurry; die discharge flow channel optimization: control the flow distribution of the center and the edge through CFD simulation or actual debugging; transfer roller or back roller rubber hardness adjustment: match different rubber hardness or diameter difference at different positions to balance the contact pressure; process tension and speed control: adjust the coating speed, unwinding and winding tension and other parameters to affect the slurry distribution.

[0003] Although the above-mentioned technology achieves controllability of coating thickness to some extent, the slurry is significantly affected by shear force, and excessive flow or fluid accumulation at the edge is easy to occur, resulting in serious edge accumulation or thinning, which reduces the coating quality of the product. SUMMARY

[0004] The purpose of the present application is to provide a transfer coating system, a coating control method thereof and a coating device to solve the problem that the existing coating method is prone to edge accumulation or thinning of the coating.

[0005] In a first aspect, the present application provides a transfer coating system, comprising: a coating roller, one side of the coating roller is provided with a slurry tank, in the process of self-rotation of the coating roller, the slurry in the slurry tank is coated on the surface of the coating roller, so as to form a coating area on the surface of the coating roller; a back roller, in the process of self-rotation of the back roller, the back roller is used for conveying a substrate, so that the coating of the coating area is transferred to the surface of the substrate, and a slurry coating is formed on the surface of the substrate; a doctor blade, the doctor blade is an oval structure with curved surface change, and is arranged on one side of the coating roller through an angle position control mechanism, the included angle between the blade arc of the doctor blade and the tangent of the coating roller in the horizontal direction is a feeding angle, and the angle position control mechanism is used for adjusting the feeding angle; a thickness detection component, the thickness detection component is arranged on one side of the back roller, and is used for collecting the edge thickness of the slurry coating; A control unit electrically connected with the angle control mechanism and the thickness detection component, configured to control the angle control mechanism to rotate to adjust the feeding angle according to a difference between the edge thickness of the slurry coating obtained by the thickness detection component and a preset thickness range.

[0006] In one possible implementation, the control unit comprises: a data processing module configured to compare the thickness of the slurry coating obtained by the thickness detection component with the preset thickness range to generate a deviation value; a control algorithm module configured to generate an angle adjustment instruction based on the deviation value; an execution module configured to convert the angle adjustment instruction into a driving signal of the angle control mechanism to realize real-time adjustment of the feeding angle.

[0007] In one possible implementation, the control algorithm module comprises: a first control module configured to control the angle control mechanism to rotate to increase the feeding angle when it is detected that the slurry coating of the substrate edge is greater than an upper limit value of the preset thickness range value; a second control module configured to control the angle control mechanism to rotate to decrease the feeding angle when it is detected that the slurry coating of the substrate edge is less than a lower limit value of the preset thickness range value.

[0008] In one possible implementation, the short axis of the doctor blade is tangentially parallel to the coating roller in the horizontal direction in the initial state, and when the doctor blade rotates counterclockwise, the instantaneous curvature radius of the blade edge gradually changes from a first curvature radius to a second curvature radius, and the feeding angle gradually decreases from a first angle value to a second angle value; wherein the first curvature radius is less than the second curvature radius, and the second angle value is less than the first angle value.

[0009] In one possible implementation, the curvature of the doctor blade gradually changes to satisfy the following relationship:

[0010] wherein θ is the rotation angle, a is the major axis radius of the doctor blade, b is the minor axis radius of the doctor blade, and R(θ) is the instantaneous curvature radius of the blade edge.

[0011] In one possible implementation, the adjustment range Δα of the feeding angle and the deviation value Δh of the preset thickness range value satisfy a linear relationship: Δα=k•Δh; wherein k is an adjustment coefficient (0.5° / μm≤k≤2° / μm), which is calibrated in advance according to the rheological properties of the slurry.

[0012] In one possible implementation, the first radius of curvature is 5 cm, the second radius of curvature is 10 cm, the first angle value is 30°, and the second angle value is 15°.

[0013] In one possible implementation, the first control module is configured to control the angular position control mechanism to rotate to increase the feeding angle to 22°-30° when it is detected that the slurry coating of the edge of the substrate is greater than a preset thickness value. The second control module is configured to control the angular position control mechanism to rotate to decrease the feeding angle to 15°-22° when it is detected that the slurry coating of the edge of the substrate is greater than a preset thickness value.

[0014] In one possible implementation, the feeding angle is increased or decreased by 5°, and the slurry viscosity corresponding to the gap between the doctor blade and the coating roller is reduced or increased by 20%.

[0015] In a second aspect, the present application provides a coating device comprising the transfer coating system according to the first aspect.

[0016] In a second aspect, the present application provides a coating control method based on the transfer coating system according to the first aspect, which comprises: S100, controlling the rotation of the coating roller and the backing roller to start the coating process, obtaining an initial feeding angle formed between the doctor blade and the coating roller, and collecting the thickness of the slurry coating edge online; S200, determining whether the thickness of the slurry coating edge exceeds a preset thickness range; S300, if the thickness exceeds the limit, controlling the angular position control mechanism to rotate to adjust the feeding angle according to the difference between the thickness of the slurry coating edge and the preset thickness range, until the thickness of the slurry coating edge is stabilized within the preset thickness range.

[0017] In one possible implementation, the S300 specifically comprises: S310, when it is detected that the thickness of the slurry coating of the edge of the substrate is greater than the upper limit value of the preset thickness range, controlling the angular position control mechanism to rotate to increase the feeding angle; S320, when it is detected that the thickness of the slurry coating of the edge of the substrate is less than the lower limit value of the preset thickness range, controlling the angular position control mechanism to rotate to decrease the feeding angle.

[0018] The present application has at least the following technical effects: The transfer coating system provided by the application controls the rotation of the angle control mechanism to adjust the feeding angle according to the difference between the slurry coating edge thickness and the preset thickness range, so as to accurately adjust the shear force at the outlet of the scraper by adjusting the feeding angle, and adjust the slurry viscosity by changing the shear force, and then adjust the coating thickness; the shear force regulation mechanism can effectively inhibit the problems of slurry accumulation, thinning and coating leakage at the coating edge, so as to improve the thickness uniformity of the coating edge; the shear thinning characteristics of the non-Newtonian fluid can make the slurry viscosity controllable in spatial distribution, improve the coating stability of the edge area, and through online closed-loop feedback to regulate the edge thickness in real time, significantly improve the overall coating consistency, reduce the rework and defective rate, and be suitable for coating processes of various slurry systems, and have a wide application range. BRIEF DESCRIPTION OF DRAWINGS In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed to be used in the description of the specific embodiments or prior art will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0019] Figure 1 The overall structure schematic diagram of a transfer coating system provided by the embodiment of the present application is shown in the figure. Figure 2 The module connection schematic diagram of the control system of a transfer coating system provided by the embodiment of the present application is shown in the figure. Figure 3 The internal module connection schematic diagram of the control unit provided by the embodiment of the present application is shown in the figure. Figure 4 The internal module connection schematic diagram of the control algorithm module provided by the embodiment of the present application is shown in the figure. Figure 5 The flowchart of a coating control method provided by the embodiment of the present application is shown in the figure. Figure 6 The specific flowchart of step S300 in a coating control method provided by the embodiment of the present application is shown in the figure.

[0020] Figure: 1-coating roller tangent along the horizontal direction; 2-feeding angle; 3-scraper; 4-chute; 5-slurry accumulation area; 6-angle control mechanism; 7-coating roller; 8-back roller; 9-thickness detection component; 10-control unit; 11-data processing module; 12-control algorithm module; 13-execution module; 14-first control module; 15-second control module. DETAILED DESCRIPTION

[0021] The technical solutions of the present application will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0022] Those skilled in the art can understand that, unless otherwise defined, all the terms (including technical terms and scientific terms) used herein have the same meaning as that generally understood by those skilled in the art to which the present application belongs. It should also be understood that the terms such as those defined in a general dictionary should be understood as having meanings consistent with those in the context of the prior art, and should not be interpreted to have idealized or overly formal meanings unless specifically defined as such herein.

[0023] Those skilled in the art can understand that, unless otherwise stated, the singular forms "one", "a", "said" and "the" used herein also include the plural forms. It should be further understood that the phrase "comprising" used in the specification of the present application means that the features, integers, steps, operations, elements and / or components exist, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. The phrase "and / or" used herein includes all or any one of the associated listed items and all combinations thereof.

[0024] In conjunction with Figure 1 and Figure 2 As shown in the figure, the embodiment of the present application provides a transfer coating system, which comprises a coating roller 7, a back roller 8, a doctor blade 3, a thickness detection component 9 and a control unit 10.

[0025] Specifically, one side of the coating roller 7 is provided with a slurry tank 4, and in the process of self-rotation of the coating roller 7, the slurry in the slurry tank 4 is coated on the surface of the coating roller 7 to form a coating area on the surface of the coating roller 7. The back roller 8 is used to convey the substrate in the process of self-rotation, and in the process of conveying, the coating of the coating area is transferred to the surface of the substrate to form a slurry coating layer on the surface of the substrate.

[0026] The doctor blade 3 in the embodiment adopts an oval structure with curved surface change, and the doctor blade 3 is arranged on one side of the coating roller 7 through an angular position control mechanism. The included angle between the blade arc of the doctor blade 3 and the tangent 1 of the coating roller in the horizontal direction is set as a feeding angle 2. The rotation of the doctor blade 3 is driven by the rotation shaft of the angular position control mechanism 6, so as to adjust the feeding angle 2, thereby corresponding to different slurry viscosities.

[0027] It can be understood that generally the transfer coating is greatly affected by the change of viscosity, too high viscosity of the slurry will cause thick edge of the coating edge, too low viscosity of the slurry will cause thinning of the slurry accumulation overflow edge, and the transfer coating is generally an open tank 4, the slurry is directly contacted with the environment, which generally causes the viscosity of the slurry to gradually deviate from the normal coating requirement viscosity, at this time the embodiment can change the viscosity of the slurry passing through the gap by increasing or decreasing the feeding angle 2.

[0028] In order to facilitate the adjustment of the edge thickness of the slurry coating, the embodiment is provided with a thickness detection component 9 on one side of the back roller 8, and the edge thickness of the slurry coating is collected (or detected) by the thickness detection component 9. It should be noted that the thickness detection component 9 is arranged to detect after the back roller 8 discharges, and a corresponding drying device is generally arranged between the thickness detection component 9 and the back roller 8 to improve the stability of the coating and ensure that the coating thickness detection is more accurate. Alternatively, the thickness detection component 9 can use a beta ray, laser or infrared thickness gauge and the like to realize the thickness detection of the slurry.

[0029] The control unit 10 is electrically connected with the angular position control mechanism 6 and the thickness detection component 9 respectively, and is used to control the angular position control mechanism 6 to rotate to adjust the feeding angle 2 according to the difference between the edge thickness of the slurry coating obtained by the thickness detection component 9 and the preset thickness range, so as to adjust the shear force at the outlet of the doctor blade 3 by adjusting the feeding angle 2, change the viscosity of the slurry by the shear force, and then adjust the thickness of the coating by changing the viscosity of the slurry. The preset thickness range can be regarded as the normal thickness range value of the slurry coating, and the thickness value within the range value can not need to adjust the corresponding feeding angle 2.

[0030] The embodiment adopts an online real-time detection component of the edge thickness to detect the thickness of the coating, feeds the detection data to the control unit 10, adjusts the angular position control mechanism 6 through the control unit 10, adjusts the included angle between the arc of the doctor blade 3 and the tangent of the coating roller 7, and changes the shear force distribution of the slurry at the outlet of the doctor blade 3. Specifically, according to the pressure formula P = F / S, wherein P is the pressure, F is the pressure applied by the doctor blade 3 (which is generally kept stable within a certain range), and S is the force area of the fluid, when the feeding angle 2 changes and the force area S decreases, the pressure P per unit area increases, thereby causing the shear force of the slurry in the region to increase. Due to the shear thinning effect, the viscosity of the slurry decreases and the fluidity increases, so that the edge overflow is more likely to occur; on the contrary, when the included angle increases, the shear force of the slurry on the doctor blade 3 weakens, the viscosity of the slurry increases, and the fluidity decreases, effectively inhibiting the accumulation and overflow phenomenon. Wherein, Figure 1 The amount of slurry accumulated in the slurry accumulation area 5 shown in the figure is related to the viscosity of the slurry, the lower the viscosity, the less slurry the slurry accumulation area 5 accumulates, and the higher the viscosity, the more slurry the slurry accumulation area 5 accumulates.

[0031] The transfer coating system provided by the embodiments of the present application collects the edge thickness of the slurry coating layer on line, controls the rotation of the angle position control mechanism 6 to adjust the feeding angle 2 according to the difference between the edge thickness of the slurry coating layer and the preset thickness range, thereby accurately adjusting the shear force at the outlet of the doctor blade 3 by adjusting the feeding angle 2, adjusting the slurry viscosity by changing the shear force, and further adjusting the coating thickness. Through the shear force regulation mechanism, the present application effectively suppresses problems such as coating edge accumulation, thinning and coating leakage, so as to improve the thickness uniformity of the coating edge. The shear thinning characteristics of non-Newtonian fluid are utilized to make the slurry viscosity controllable in spatial distribution, improve the coating stability of the edge region, and significantly improve the overall coating consistency, reduce rework and the defective rate by real-time regulation and control of the edge thickness through on-line closed-loop feedback. The present application is suitable for coating processes of various slurry systems and has a wide range of applications.

[0032] In some embodiments, as shown in Figure 3 The control unit 10 includes a data processing module 11, a control algorithm module 12 and an execution module 13.

[0033] Specifically, the data processing module 11 is configured to compare the slurry coating thickness collected by the thickness detection component 9 with the preset thickness range to generate a deviation value Δh. The control algorithm module 12 is configured to generate an angle adjustment instruction based on the deviation value Δh through a PID control algorithm. The execution module 13 is configured to convert the angle adjustment instruction into a driving signal of the angle position control mechanism, so as to realize real-time adjustment of the feeding angle 2.

[0034] Optionally, the adjustment range Δα of the feeding angle 2 and the deviation value Δh of the preset thickness range value satisfy a linear relationship: Δα=k•Δh. Wherein, k is an adjustment coefficient (0.5° / μm≤k≤2° / μm), which is calibrated in advance according to the rheological properties of the slurry.

[0035] Optionally, as shown in Figure 4 The control algorithm module 12 includes a first control module 14 and a second control module 15. The first control module 14 is configured to control the rotation of the angle position control mechanism 6 to increase the feeding angle 2 when it is detected that the slurry coating layer of the edge of the substrate is greater than the upper limit value of the preset thickness range value.

[0036] The second control module 15 is configured to control the rotation of the angle position control mechanism 6 to reduce the feeding angle 2 when it is detected that the slurry coating layer of the edge of the substrate is less than the lower limit value of the preset thickness range value.

[0037] It should be noted that the embodiment is based on the shear thinning characteristics of non-Newtonian fluid, and the shear force distribution of the slurry at the outlet of the scraper 3 is changed by adjusting the feed angle 2: when the feed angle 2 decreases, the unit area pressure increases, the shear force increases, the slurry viscosity decreases, the flowability increases, and the edge overflow is prone to occur; and when the included angle increases, the shear force decreases, the slurry viscosity increases, the flowability decreases, the accumulation and overflow are inhibited, and thus the edge thickness is controlled, that is, the present application is realized by changing the shear force to change the slurry viscosity, and then changing the thickness of the coating layer, which is a fluid mechanics internal control mechanism to realize the adjustment of the coating layer edge thickness.

[0038] In order to specifically describe the adjustment process of the feed angle 2, it is assumed that the short axis of the scraper 3 and the coating roller are parallel along the horizontal direction tangent 1 in the initial state, and the blade edge instantaneous curvature radius of the scraper 3 gradually changes from a first curvature radius to a second curvature radius when the scraper 3 rotates counterclockwise, and the feed angle 2 gradually decreases from a first angle value to a second angle value; wherein the first curvature radius is smaller than the second curvature radius, and the second angle value is smaller than the first angle value, that is, the smaller the curvature radius, the greater the bending degree, and the corresponding angle value is also greater.

[0039] Optionally, the curvature of the scraper 3 gradually changes to satisfy the following relationship:

[0040] Wherein, θ is the rotation angle, a is the long axis radius of the scraper 3 (ellipse), b is the short axis radius of the scraper 3 (ellipse), and R(θ) is the instantaneous curvature radius of the blade edge.

[0041] Optionally, the first curvature radius is 5 cm, the second curvature radius is 10 cm, the first angle value is 30°, and the second angle value is 15°, that is, when the instantaneous curvature radius of the blade edge is 5 mm, the corresponding feed angle 2 is 30°, and when the instantaneous curvature radius of the blade edge is 10 mm, the corresponding feed angle 2 is 15°. During the rotation of the scraper 3, the curvature radius of the blade edge surface fluctuates in the range of 5 mm to 10 mm, and the corresponding feed angle 2 fluctuates in the range of 30° to 15°. By determining the corresponding relationship of the above parameters, the corresponding adjustment can be realized by the PID control algorithm, so that the thickness of the slurry coating layer edge can be more accurately adjusted.

[0042] Optionally, the first control module 14 is configured to control the angular position control mechanism 6 to rotate to increase the feed angle 2 to 22°-30° when it is detected that the slurry coating layer of the substrate edge is greater than the preset thickness value, so as to weaken the shear force of the slurry, increase the viscosity, and reduce the flowability to prevent overflow.

[0043] Optionally, the second control module 15 is configured to control the angular position control mechanism 6 to rotate to decrease the feeding angle 2 to 15°-22° when it is detected that the slurry coating of the substrate edge is greater than the preset thickness value, so as to increase the unit area pressure P (P=F / S, S is the fluid force area), enhance the slurry shear force, reduce the viscosity, and enhance the fluidity to inhibit the accumulation.

[0044] In a specific embodiment, when it is detected that the edge thickness is too thick (i.e. beyond the preset thickness range), the feeding angle 2 needs to be decreased to increase the shear force, so as to reduce the viscosity of the slurry, such as the negative electrode slurry with a solid content of 50% and a viscosity of 8000 cp, and the required coating thickness range is 60±2 μm. When the feeding angle 2 is 20°, the edge thickness of the coating is 65 μm, and the edge is 3 μm too thick. At this time, the angle can be decreased to 18° to increase the shear force to reduce the viscosity to increase the overflow, so as to control the edge thickness within the range of 60±2 μm, thereby meeting the coating thickness requirement.

[0045] Optionally, when the feeding angle 2 is increased by 5°, the viscosity of the slurry passing through the gap between the doctor blade 3 and the coating roller 7 is reduced by 20%; or when the feeding angle 2 is decreased by 5°, the viscosity of the slurry passing through the gap between the doctor blade 3 and the coating roller 7 is increased by 20%, so that high-viscosity and low-viscosity slurries can be coated. For example, for high-viscosity coating, the elliptical doctor blade 3 can be rotated counterclockwise to decrease the included angle and reduce the viscosity to improve the edge thickness.

[0046] In a specific embodiment, when it is detected that the edge thickness is too thin (i.e. below the preset thickness range), the feeding angle 2 needs to be increased to decrease the shear force, so as to increase the viscosity of the slurry, such as the negative electrode slurry with a solid content of 40% and a viscosity of 2000 cp, and the required coating thickness range is 60±2 μm. When the feeding angle 2 is 20°, the edge thickness of the coating is 55 μm, and the edge is 3 μm too thin. At this time, the angle can be increased to 22° to decrease the shear force to increase the viscosity to reduce the overflow, so as to control the edge thickness within the range of 60±2 μm, thereby meeting the coating thickness requirement.

[0047] In a second aspect, the embodiments of the present application also provide a coating device, which comprises the transfer coating system as described in the foregoing embodiments. In addition, the coating device further comprises a support, a transmission mechanism, and a coating supply group and other components. The specific installation mode of these structures can refer to the existing coating device, and the embodiments of the present application will not be described in detail.

[0048] The coating device provided by the application includes the transfer coating system of the foregoing embodiments, the transfer coating system acquires the edge thickness of the slurry coating layer online, and controls the rotation of the angle control mechanism 6 to adjust the feeding angle 2 according to the difference between the edge thickness of the slurry coating layer and the preset thickness range, so as to accurately adjust the shear force at the outlet of the doctor blade 3 by adjusting the feeding angle 2, adjust the slurry viscosity by changing the shear force, and further adjust the coating thickness; the shear force regulation mechanism can effectively inhibit problems such as coating edge accumulation, thinning and coating leakage, so as to improve the thickness uniformity of the coating edge; the shear thinning characteristics of the non-Newtonian fluid are used to make the slurry viscosity controllable in spatial distribution, improve the coating stability of the edge region, and significantly improve the overall coating consistency, reduce rework and the defective rate by regulating the edge thickness in real time through online closed-loop feedback, and the coating process is suitable for various slurry systems and has a wide range of applications.

[0049] A third aspect, as Figure 5 shown, the application also provides a coating control method based on the transfer coating system according to any one of the foregoing embodiments, and the coating control method comprises the following steps: S100, controlling the rotation of the coating roller 7 and the backing roller 8 to start the coating process, acquiring the initial feeding angle between the doctor blade 3 and the coating roller 7, and acquiring the edge thickness of the slurry coating layer online.

[0050] Specifically, the initial feeding angle can be acquired by the control unit 10 when the coating process is started, so that the feeding angle 2 can be adjusted in time according to the acquired thickness data, and the regulation efficiency is improved.

[0051] S200, determining whether the edge thickness of the slurry coating layer exceeds the preset thickness range.

[0052] Specifically, the data processing module 11 in the control unit 10 compares the edge thickness of the slurry coating layer with the preset thickness range and generates a specific deviation value.

[0053] S300, if the thickness exceeds the limit, the rotation of the angle control mechanism 6 is controlled to adjust the feeding angle 2 according to the difference between the edge thickness of the slurry coating layer and the preset thickness range, until the edge thickness of the slurry coating layer is stabilized within the preset thickness range.

[0054] Specifically, when the edge thickness of the slurry coating layer exceeds the preset thickness range, it is considered that the thickness exceeds the limit. When the thickness exceeds the limit, the size of the feeding angle 2 needs to be adjusted according to the specific deviation value until the detected thickness can meet the requirement of the preset thickness range.

[0055] Optionally, as Figure 6 shown, the S300 specifically comprises: S310, when detecting that the slurry coating of the substrate edge is greater than the upper limit value of the preset thickness range value, the angle position control mechanism 6 is controlled to rotate to increase the feeding angle 2.

[0056] S320, when detecting that the slurry coating of the substrate edge is less than the lower limit value of the preset thickness range value, the angle position control mechanism 6 is controlled to rotate to decrease the feeding angle 2.

[0057] It should be noted that when the control unit adjusts the feeding angle through the rotation of the angle position control mechanism, the adjustment can be specifically adjusted according to the linear relationship between the adjustment range Δa of the feeding angle in the foregoing embodiments and the deviation value Δh of the preset thickness range value, which will not be described in detail here. In addition, the above steps S310 and S320 only represent the control mode of two different cases, and do not represent the sequence between the steps.

[0058] The coating control method provided by the embodiments of the present application collects the edge thickness of the slurry coating on line, and controls the rotation of the angle position control mechanism to adjust the feeding angle according to the difference between the edge thickness of the slurry coating and the preset thickness range, so as to accurately adjust the shear force at the outlet of the doctor blade by adjusting the feeding angle, adjust the slurry viscosity by changing the shear force, and then adjust the coating thickness; through the shear force regulation mechanism, the problems of coating edge accumulation, thinning and missing coating are effectively inhibited, so as to improve the thickness uniformity of the coating edge; the shear thinning characteristics of the non-Newtonian fluid are utilized to make the slurry viscosity controllable in spatial distribution, improve the coating stability of the edge region, and through the online closed-loop feedback to regulate the edge thickness in real time, the overall coating consistency is significantly improved, and the rework and defective rate are reduced.

[0059] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0060] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more.

[0061] In the description of the application, it is necessary to explain that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium; can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances. In the description of the specification, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0062] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A transfer coating system, characterized in that, include: A coating roller, wherein a slurry trough is provided on one side of the coating roller, and during the rotation of the coating roller, the slurry in the slurry trough is coated on the surface of the coating roller to form a coating area on the surface of the coating roller; A back roller, which is used to transport the substrate during its rotation, so that the coating in the coating area is transferred to the surface of the substrate and a slurry coating is formed on the surface of the substrate; The scraper is an elliptical structure with a curved surface and is set on one side of the coating roller by an angle control mechanism. The angle between the arc of the scraper blade and the horizontal tangent of the coating roller is the feeding angle. The angle control mechanism is used to adjust the feeding angle. A thickness detection component is disposed on one side of the back roller and is used to collect the thickness of the slurry coating edge. The control unit is electrically connected to the angle control mechanism and the thickness detection component, respectively, and is used to control the angle control mechanism to rotate to adjust the feeding angle based on the difference between the thickness of the slurry coating edge obtained by the thickness detection component and a preset thickness range.

2. The transfer coating system according to claim 1, characterized in that, The control unit includes: The data processing module is used to compare the thickness of the slurry coating collected by the thickness detection component with a preset thickness range and generate a deviation value. The control algorithm module is used to generate an angular adjustment command based on the deviation value; An execution module is used to convert the angle adjustment command into a drive signal for the angle control mechanism, thereby realizing real-time adjustment of the feeding angle.

3. The transfer coating system according to claim 2, characterized in that, The control algorithm module includes: The first control module is used to control the corner control mechanism to rotate to increase the feeding angle when the detected slurry coating at the edge of the substrate is greater than the upper limit of the preset thickness range. The second control module is used to control the corner control mechanism to rotate to reduce the feeding angle when the slurry coating at the edge of the substrate is detected to be less than the lower limit of a preset thickness range.

4. The transfer coating system according to claim 3, characterized in that, In the initial state, the short axis of the scraper is parallel to the horizontal tangent of the coating roller. When the scraper rotates counterclockwise, the instantaneous radius of curvature of the scraper's cutting edge gradually changes from a first radius of curvature to a second radius of curvature, and the feed angle gradually decreases from a first angle value to a second angle value; wherein, the first radius of curvature is smaller than the second radius of curvature, and the second angle value is smaller than the first angle value.

5. The transfer coating system according to claim 4, characterized in that, The curvature gradient of the scraper satisfies the following relationship: Where θ is the rotation angle, a is the major axis radius of the scraper, b is the minor axis radius of the scraper, and R(θ) is the instantaneous radius of curvature of the cutting edge.

6. The transfer coating system according to claim 5, characterized in that, The adjustment range Δα of the feed angle and the deviation Δh of the preset thickness range value satisfy a linear relationship: Δα = k•Δh; Where k is the adjustment coefficient (0.5° / μm≤k≤2° / μm), which is pre-calibrated based on the rheological properties of the slurry.

7. The transfer coating system according to claim 6, characterized in that, The first radius of curvature is 5cm, the second radius of curvature is 10cm, the first angle is 30°, and the second angle is 15°.

8. The transfer coating system according to claim 7, characterized in that, The first control module is used to control the corner control mechanism to rotate to increase the feeding angle to 22° to 30° when it detects that the slurry coating at the edge of the substrate is greater than a preset thickness value. The second control module is used to control the corner control mechanism to rotate to reduce the feeding angle to 15° to 22° when it detects that the slurry coating at the edge of the substrate is greater than a preset thickness value.

9. The transfer coating system according to claim 2, characterized in that, Increasing or decreasing the feed angle by 5° will correspondingly decrease or increase the viscosity of the slurry through the gap between the scraper and the coating roller by 20%.

10. A coating apparatus, characterized in that, Includes the transfer coating system as described in any one of claims 1 to 9.

11. A coating control method, characterized in that, Based on the transfer coating system as described in any one of claims 1 to 9, the coating control method includes: S100 controls the rotation of the coating roller and back roller to start the coating process, obtains the initial feed angle formed between the doctor blade and the coating roller, and collects the edge thickness of the slurry coating online. S200, determine whether the edge thickness of the slurry coating exceeds a preset thickness range; S300, if the thickness exceeds the limit, the angle control mechanism is controlled to rotate to adjust the feeding angle based on the difference between the thickness of the slurry coating edge and the preset thickness range, until the thickness of the slurry coating edge stabilizes within the preset thickness range.

12. The coating control method according to claim 11, characterized in that, Specifically, S300 includes: S310, when the slurry coating at the edge of the substrate is detected to be greater than the upper limit of the preset thickness range, the corner control mechanism is controlled to rotate to increase the feeding angle; S320, when it is detected that the slurry coating at the edge of the substrate is less than the lower limit of the preset thickness range, the corner control mechanism is controlled to rotate to reduce the feeding angle.

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