Coating system and coating method

Abstract

The invention discloses a coating system and a coating method.The coating system comprises a conveying branch and a backflow branch; the conveying branch comprises a coating pump, a first valve body and a coating die head; the backflow branch comprises a coating pump, a second valve body and a slurry supply container; the output end of the coating pump is communicated with one end of the first valve body, and the other end of the first valve body is communicated with the input end of the coating die head; the output end of the coating pump is communicated with one end of the second valve body, and the other end of the second valve body is communicated with the slurry supply container. Communication and blocking between the coating pump and the coating die head can be achieved through opening and closing of the first valve body, communication and blocking between the coating pump and the slurry supply container can be achieved through opening and closing of the second valve body, and the slurry supply container can be opened and closed within the starting time and the stopping time of the coating pump by adjusting the opening and closing sequence and the opening and closing time of the first valve body and the second valve body. And the slurry which is conveyed outwards within the starting time and the stopping time of the coating pump and is non-uniform in pressure flows back into the slurry supply container through the backflow branch.

Description

Technical Field

[0001] The present invention relates to the field of coating technology, and in particular to a coating system and a coating method. Background Art

[0002] Coating is the process of coating a viscous paste evenly, continuously or intermittently on a substrate. Coating technology has been widely used in many industries such as new energy batteries, solar cells, optical films, and flexible circuit boards. The quality of the film formed by coating directly determines the performance of the final product, and the coating process is a key factor affecting the quality of the film.

[0003] The existing coating process is as follows: the coating pump transports the coating liquid in the slurry barrel to the coating die head, the coating die head and the substrate move relative to each other, and the coating die head spits the slurry onto the surface of the substrate at a set speed and set pressure to form a coating on the substrate. The start and stop of the coating process are controlled by opening and closing the coating pump.

[0004] The coating pump has a start time and a stop time. During the start time, the pressure of the slurry output by the coating pump gradually increases to the set pressure. During the stop time, the pressure of the slurry output by the coating pump gradually decreases to zero. Therefore, during the start time and the stop time, the pressure of the slurry output by the coating pump is unstable, resulting in uneven coating thickness areas at the start and stop stages of coating. The uneven coating thickness areas require additional removal processes to remove them, and the uneven coating thickness areas also lead to waste of slurry. Summary of the invention

[0005] In view of this, the present invention provides a coating process and a coating method to solve the problem that the pressure of the slurry output by the existing coating pump is unstable at the start time and the stop time, resulting in uneven thickness areas of the coating at the start and stop stages of the coating, and the uneven thickness areas of the coating require an additional removal process to remove them, and the uneven thickness areas of the coating also lead to waste of slurry.

[0006] In a first aspect, the present invention provides a coating process, comprising a delivery branch and a return branch;

[0007] The delivery branch includes a coating pump, a first valve body and a coating die head; the reflux branch includes the coating pump, a second valve body and a slurry supply container;

[0008] The output end of the coating pump is connected to one end of the first valve body, and the other end of the first valve body is connected to the input end of the coating die head; the output end of the coating pump is connected to one end of the second valve body, and the other end of the second valve body is connected to the slurry supply container.

[0009] The opening and closing of the first valve body can realize the connection and blocking between the coating pump and the coating die head, and the opening and closing of the second valve body can realize the connection and blocking between the coating pump and the slurry supply container. By adjusting the opening and closing sequence and the opening and closing time of the first valve body and the second valve body, the slurry with uneven pressure transported outward during the start time and stop time of the coating pump can be refluxed into the slurry supply container through the reflux branch during the start time and stop time of the coating pump; when the coating pump transports slurry with uniform pressure outward, the pressure is uniformly transported to the coating die head through the delivery branch, so as to reduce the time for the coating pump to transport uneven slurry to the coating die head, thereby reducing the uneven thickness area in the coating, thereby reducing the removal amount of the removal process, and reducing the waste of slurry.

[0010] In an optional embodiment, it also includes a slurry supply branch, which includes the slurry supply container, a third valve body and the coating pump, the slurry supply container is connected to one end of the third valve body, and the other end of the third valve body is connected to the input end of the coating pump.

[0011] When the coating pump needs to replenish the slurry in its own containing chamber, the third valve body opens and the coating pump draws the slurry in the slurry supply container into its own containing chamber. When the coating pump transports the slurry outward, the third valve body closes to prevent the slurry in the coating pump's own containing chamber from flowing back into the slurry supply container.

[0012] In an optional embodiment, it further includes a substrate, wherein the substrate is located below the output end of the coating die head, and the distance between the substrate and the output end of the coating die head is a first preset value.

[0013] By adjusting the distance between the substrate and the output end of the coating die, the thickness of the coating formed on the substrate can be adjusted, and setting the distance to the first preset value is conducive to forming a flat and smooth coating surface on the substrate.

[0014] In an optional embodiment, it also includes:

[0015] A lifting drive member is connected to the coating die head, and the lifting drive member can drive the coating die head away from or close to the substrate.

[0016] The distance between the output end of the coating die head and the substrate can be conveniently adjusted by lifting the driving part.

[0017] A translation driving member, wherein the translation driving member is connected to the substrate or the coating die head, and the translation driving member can drive the substrate to move along a first direction, or the translation driving member can drive the coating die head to move along a second direction.

[0018] The coating die head or the substrate can be driven to move by the translation driving member, so that the coating die head can evenly coat the slurry on the substrate.

[0019] In an optional implementation, it also includes:

[0020] A detection member, disposed between the coating pump and the first valve body, for obtaining a pressure value of the slurry passing through the first valve body;

[0021] The fourth valve body is arranged between the second valve body and the slurry supply container, and the fourth valve body is used to adjust the flow rate of the slurry passing through the fourth valve body.

[0022] In a second aspect, the present invention provides a coating method, which is applied to the above-mentioned coating system, and the coating method comprises:

[0023] When coating is required, the second valve body is opened, and the coating pump is turned on, the second valve body remains in the open state for the first preset time, and then the second valve body is closed, and the first valve body is opened in advance or lags behind the second preset time based on the time node of closing the second valve body;

[0024] When coating needs to be stopped, the first valve body is closed, and the second valve body is opened in advance or after a third preset time based on the time node of closing the first valve body.

[0025] According to the above-mentioned technical means, in the coating system provided by the present invention, it is realized that during the start-up time and the stop-time of the coating pump, the slurry with uneven pressure transported outward during the start-up time and the stop-time of the coating pump is refluxed into the slurry supply container through the reflux branch, so as to reduce the time for the coating pump to transport the uneven slurry to the coating die head, thereby reducing the uneven thickness area in the coating, thereby reducing the removal amount of the removal process and reducing the waste of slurry.

[0026] In an optional implementation, after the step of opening the first valve body in advance or after the second preset time based on the time node of closing the second valve body, the method further includes:

[0027] The first valve body remains in the open state for a fourth preset time.

[0028] According to the above technical means, when the coating pump delivers slurry with uniform pressure to the outside, the pressure is evenly delivered to the coating die head through the delivery branch.

[0029] In an optional embodiment, it further comprises a substrate and a lifting drive member, wherein the lifting drive member is connected to the coating die head, and the substrate is located below the output end of the coating die head;

[0030] Before the first valve body is opened in advance or after a second preset time based on the time node of closing the second valve body, the method further includes:

[0031] The lifting drive member is turned on, and the drive member drives the coating die head to move away from or close to the substrate, so that the distance between the output end of the coating die head and the substrate is a first preset value.

[0032] According to the above technical means, the distance between the output end of the coating die head and the substrate is adjusted.

[0033] In an optional embodiment, it further includes a translation drive, which is connected to the substrate and / or the coating die head; the translation drive can drive the substrate to move along the first direction and / or the translation drive can drive the coating die head to move along the second direction;

[0034] After the step of closing the second valve body, before the step of opening the first valve body in advance or after the second preset time based on the time node of closing the second valve body, the method further includes:

[0035] The translation driving member is opened in advance or in delay of a fifth preset time based on a time node of closing the second valve body.

[0036] In an optional embodiment, it further comprises a slurry supply branch, the slurry supply branch comprises the slurry supply container, a third valve body and the coating pump, the slurry supply container is connected to one end of the third valve body, and the other end of the third valve body is connected to the input end of the coating pump;

[0037] When the coating pump needs to absorb the slurry, the third valve body is opened, the coating pump is turned on, the third valve body remains in the open state for a sixth preset time, the coating pump is turned off, and the third valve body is closed at the same time.

[0038] According to the above-mentioned means, the slurry in the containing chamber of the coating pump itself is replenished. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 is a structural schematic diagram of a coating system according to an embodiment of the present invention;

[0041] Figure 2 It is a schematic flow chart of a coating method according to an embodiment of the present invention.

[0042] Description of reference numerals:

[0043] 1. Coating pump;

[0044] 2. The first valve body;

[0045] 3. Coating die head;

[0046] 4. Second valve body;

[0047] 5. Slurry supply container;

[0048] 6. The third valve body;

[0049] 7. Substrate;

[0050] 8. Platform;

[0051] 91. Testing component; 92. Fourth valve body. DETAILED DESCRIPTION

[0052] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0054] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0056] The embodiment of the present invention provides a coating system, such as Figure 1 As shown, it includes a delivery branch and a return branch;

[0057] The delivery branch includes a coating pump 1 , a first valve body 2 and a coating die head 3 ; the reflux branch includes a coating pump 1 , a second valve body 4 and a slurry supply container 5 .

[0058] The device connection relationship in each branch is as follows:

[0059] The output end of the coating pump 1 is connected to one end of the first valve body 2, and the other end of the first valve body 2 is connected to the input end of the coating die head 3; the output end of the coating pump 1 is connected to one end of the second valve body 4, and the other end of the second valve body 4 is connected to the slurry supply container 5.

[0060] Specifically, the coating pump 1 can be a syringe pump, a PT pump, a CT pump or other reciprocating pumps. Preferably, in the present embodiment, the coating pump 1 is a syringe pump. A accommodating chamber is provided in the coating pump 1 for holding the slurry. The coating pump 1 is provided with an outlet, which is the output end of the coating pump 1. The coating pump 1 can transport the slurry outward through the outlet; the first valve body 2 and the second valve body 4 can both be a one-way valve, a solenoid valve or other flow control valves. Of course, the first valve body 2 and the second valve body 4 can also be a combination valve, such as a three-way valve. In the present embodiment, a one-way valve is preferably used; the coating die 3 has a feed port, a feed port and a flow channel. The feed port is the input end of the coating die 3, and the feed port is the output end of the coating die 3. The slurry can be transported to the flow channel through the feed port. The flow channel is used to evenly distribute the slurry to the discharge port, and the discharge port is used to spit out the slurry; the slurry supply container 5 is a container for holding the slurry, and the slurry supply container 5 can be a slurry barrel or a slurry tank.

[0061] The coating system provided in the present embodiment can achieve communication and blocking between the coating pump 1 and the coating die 3 by opening and closing the first valve body 2, and can achieve communication and blocking between the coating pump 1 and the slurry supply container 5 by opening and closing the second valve body 4. By adjusting the opening and closing sequence and the opening and closing time of the first valve body 2 and the second valve body 4, the slurry with uneven pressure delivered outward during the start time and stop time of the coating pump 1 can be refluxed into the slurry supply container 5 through the reflux branch during the start time and stop time of the coating pump 1; and when the coating pump 1 delivers slurry with uniform pressure outward, the slurry with uniform pressure is delivered to the coating die 3 through the delivery branch, so as to reduce the time for the coating pump 1 to deliver uneven slurry to the coating die 3, thereby reducing the uneven thickness area in the coating, thereby reducing the removal amount of the removal process, and reducing the waste of slurry.

[0062] In this embodiment, as an optional implementation, it also includes a slurry supply branch, which includes a slurry supply container 5, a third valve body 6 and a coating pump 1. The equipment connection relationship in the slurry supply branch is: the slurry supply container 5 is connected to one end of the third valve body 6, and the other end of the third valve body 6 is connected to the input end of the coating pump 1. The third valve body 6 can be a one-way valve, a solenoid valve or other flow control valve. Of course, the first valve body 2 and the second valve body 4 and the third valve body 6 can also be a combination valve, such as a four-way valve. When the coating pump 1 needs to replenish the slurry in its own receiving chamber, the third valve body 6 is opened, and the coating pump 1 draws the slurry in the slurry supply container 5 into its own receiving chamber. When the coating pump 1 transports the slurry outward, the third valve body 6 is closed to prevent the slurry in the coating pump 1's own receiving chamber from flowing back into the slurry supply container 5.

[0063] In this embodiment, as an optional implementation, the conveying branch, the return branch and the slurry supply branch are all provided with pipelines for achieving connectivity between various devices.

[0064] In this embodiment, as an optional implementation, it also includes a substrate 7, which is located directly below the output end of the coating die 3. The spacing between the substrate 7 and the output end of the coating die 3 is a first preset value, which can be adjusted according to the thickness of the coating. By adjusting the spacing between the substrate 7 and the output end of the coating die 3, the thickness of the coating formed on the substrate 7 can be adjusted. The spacing between the substrate 7 and the output end of the coating die 3 is between 0.05mm and 0.2mm. If the spacing between the substrate 7 and the coating die 3 is greater than 0.2mm, the slurry on the substrate 7 is easily dispersed during the flow process, resulting in corrugated and orange peel defects on the coating surface formed on the substrate 7; if the spacing between the substrate 7 and the coating die 3 is less than 0.05mm, the slurry is subjected to excessive pressure between the coating die 3 and the substrate 7, resulting in scratches and wrinkles on the coating formed on the substrate 7, and it is easy to cause the coating head to be blocked. In this embodiment, the first preset value is 0.1mm, which is conducive to forming a flat and smooth coating surface on the substrate 7.

[0065] In this embodiment, as an optional implementation, it also includes a lifting drive component, which can be a cam mechanism, a screw mechanism, a gear rack mechanism, a cylinder, a linear motor or other linear motion drive equipment. The lifting drive component is connected to the shell of the coating die 3. The lifting drive component can drive the coating die 3 away from or close to the substrate 7 to adjust the distance between the output end of the coating die 3 and the substrate 7.

[0066] In this embodiment, as an optional implementation, it also includes a translational drive member, which can be a cam mechanism, a screw mechanism, a gear rack mechanism, a cylinder, a linear motor or other linear motion drive equipment. Of course, the translational drive member can also be a roller, and the substrate 7 is arranged around the outer circumference of the roller. Preferably, in this embodiment, the substrate 7 is a flat plate, and the translational drive member is a linear motor. The translational drive member is installed on the equipment platform 8. The mounting surface of the translational drive member is fixedly connected to the substrate 7. The translational drive member can drive the substrate 7 to move along a first direction. The first direction is a direction extending along the length of the substrate 7. The length of the discharge port of the coating die 3 is less than or equal to the length of the substrate 7. The substrate 7 moves along the first direction so that the coating die 3 sweeps over the substrate 7, thereby realizing the coating of the slurry on the substrate 7.

[0067] In an alternative embodiment, the translational drive is connected to the coating die 3 , and the translational drive can drive the coating die 3 to move along a second direction, which is also a direction extending along the length of the substrate 7 , so that the coating die 3 scans the substrate 7 .

[0068] In another replaceable embodiment, the translational drive is connected to the device platform 8, and the translational drive can drive the device platform 8 to move, thereby driving the substrate 7 to move, and then causing the substrate 7 and the coating die 3 to produce relative displacement, so that the coating die 3 scans the substrate 7 to achieve coating of the substrate.

[0069] In this embodiment, as an optional implementation, it also includes a detection member 91 and a fourth valve body 92, the detection member 91 is a pressure detection sensor, preferably, the detection member 91 is a piezoresistive pressure sensor, the detection member 91 is arranged between the coating pump 1 and the first valve body 2, that is, the two ends of the detection member 91 are respectively connected to the output end of the coating pump 1 and the first valve body 2, and the detection member 91 is used to obtain the pressure value of the slurry flowing therethrough; the fourth valve body 92 is a flow valve, preferably, the fourth valve body 92 is an electromagnetic valve, and the fourth valve body 92 is arranged between the second valve body 4 and the slurry supply container 5, that is, the two ends of the fourth valve body 92 The fourth valve body 92 is respectively connected to the second valve body 4 and the slurry supply container 5. The flow rate of the slurry flowing through it can be adjusted according to the pressure value fed back by the detection member 91. The flow rate of the slurry flowing through it can be adjusted by the opening size of the fourth valve body 92, so that the reflux speed can be adjusted. When the pressure value of the slurry flowing through the detection member 91 is greater than the preset pressure value, the opening size of the fourth valve body 92 is adjusted according to the difference between the pressure value and the preset pressure value, so as to adjust the reflux speed of the slurry, so that the slurry pressure value at the detection member 91 quickly returns to the set pressure value to ensure that the slurry pressure input to the first valve body 2 is uniform. The pressure value flowing through it can be obtained in real time through the detection member 91, so that it can be judged in real time whether the slurry input to the first valve body 2 is stable, and when the pressure value fed back by the detection member 91 is stable, the second valve body 4 can be closed in time. Based on the coating system provided in this embodiment, Figure 2 As shown, the following coating methods can be implemented accordingly:

[0070] Step S100, when coating needs to start, the second valve body 4 is opened, and the coating pump 1 is started, the second valve body 4 remains in the open state for a first preset time, and then the second valve body 4 is closed, and the first valve body 2 is opened in advance or delayed by a second preset time based on the time node of closing the second valve body 4;

[0071] Step S200: when coating needs to be stopped, the first valve body 2 is closed, and the second valve body 4 is opened in advance or after a third preset time based on the time node of closing the first valve body 2.

[0072] Specifically, step S100 includes:

[0073] S101, a set volume of slurry is absorbed into the coating pump 1's own containing chamber. The coating system also includes a slurry supply branch, which includes a slurry supply container 5, a third valve body 6 and the coating pump 1. The equipment connection relationship in the slurry supply branch is as follows: the slurry supply container 5 is connected to one end of the third valve body 6, and the other end of the third valve body 6 is connected to the input end of the coating pump 1.

[0074] In the preparation stage before coating is started, the third valve body 6 is opened, the coating pump 1 is turned on, and the coating pump 1 begins to extract the slurry in the slurry supply container 5. The slurry in the slurry supply container 5 passes through the third valve body 6 and the input end of the coating pump 1 in turn and enters the accommodating chamber of the coating pump 1 itself. The input end of the coating pump 1 is the inlet of the coating pump 1. After the third valve body 6 remains in the open state for the sixth preset time, the third valve body 6 is closed, and the coating pump 1 is closed at the same time. At this time, the set volume of slurry is sucked into the accommodating chamber of the coating pump 1 itself to meet the subsequent slurry delivery. The sixth preset time can be adjusted according to the volume of the accommodating chamber of the coating pump 1 itself and the subsequent slurry delivery amount. Preferably, the capacity of the accommodating chamber of the coating pump 1 is 5ml (cubic centimeters), and the coating pump 1 draws slurry through the third valve body 6 at a speed of 1ml / s (1 cubic centimeter per second). In this embodiment, the sixth preset time is 5 seconds. Of course, if the slurry in the containing chamber of the coating pump 1 is exhausted during the coating process, step S200 may be executed to stop coating, and then the above step S101 may be executed to replenish the slurry in the containing chamber of the coating pump 1.

[0075] S102 , adjusting the distance between the output end of the coating die head 3 and the substrate 7 to a first preset value. The coating system further includes a lifting drive component, which is connected to the coating die head 3 .

[0076] The lifting drive member is turned on, and the drive member drives the coating die head 3 to approach the substrate 7 so that the distance between the output end of the coating die head 3 and the substrate 7 is a first preset value. Preferably, the first preset value is 0.1 mm (millimeter). By adjusting the distance between the output end of the coating die head 3 and the substrate 7 to the first preset value, it is beneficial to form a flat and smooth coating surface on the substrate 7 in the subsequent steps.

[0077] Of course, when it is necessary to readjust the distance between the output end of the coating die head 3 and the substrate 7, the above step S102 can be performed. For example, after a coating pause, when coating is restarted, the above step S102 can be performed to adjust the distance between the output end of the coating die head 3 and the substrate 7 to the desired preset value.

[0078] S103, the slurry transported outwards during the start-up time of the coating pump 1 is returned. The coating pump 1 has a start-up time. During the start-up time, the pressure of the slurry output outwards by the coating pump 1 has a process of gradually increasing to a stable pressure. Therefore, during the start-up time of the coating pump 1, the pressure of the slurry output outwards by the coating pump 1 is uneven, and after the start-up time, the coating pump 1 can transport slurry with uniform pressure outwards.

[0079] Open the second valve body 4, and simultaneously start the coating pump 1, the second valve body 4 remains in the open state for a first preset time, and then closes the second valve body 4, the first preset time being greater than or equal to the start-up time of the coating pump 1, and is used to return all unstable slurry outputted outwards within the start-up time of the coating pump 1, thereby reducing slurry waste and ensuring that the coating pump 1 can output slurry with uniform pressure outwards. Of course, the first preset time may also be greater than zero and less than the start-up time of the coating pump 1, which can speed up the start-up speed of the coating system, and can also return part of the slurry within the start-up time of the coating pump 1, so as to reduce slurry waste and reduce the uneven area of ​​the coating. The start-up time of the coating pump 1 is proportional to the viscosity of the slurry, and the start-up time of the coating pump 1 is between 0.05s (seconds) and 2s. Preferably, the start-up time of the coating pump 1 is 0.2s; the first preset time is between 0.05s and 2s. Preferably, the first preset time is 0.2s; the second After the valve body 4 is in the open state for the first preset time, the second valve body 4 is closed, and the first valve body 2 is opened in advance by the second preset time based on the time node of closing the second valve body 4. The second preset time is 0.05s-2s. Preferably, the second preset time is 0.1 seconds. During the second preset time, the first valve body 2 and the second valve body 4 are both in the open state to divert the slurry with uniform pressure transported outward by the coating pump 1 to avoid suddenly closing the second valve body 4. The slurry with uniform pressure transported outward by the coating pump 1 gathers in the pipeline between the first valve body 2 and the coating pump 1, so that the pressure in the area increases; in an alternative implementation, the first valve body 2 is opened with a delay of the second preset time based on the time node of closing the second valve body 4, and the pipeline between the coating die 3 and the first valve body 2 and the flow channel of the coating die 3 itself can buffer the slurry passing through the first valve body 2 and reduce the increase in the pressure of the slurry.

[0080] In an alternative implementation, the coating system also includes a detection member 91 and a fourth valve body 92, which are arranged between the coating pump 1 and the first valve body 2, and are used to obtain the pressure value of the slurry passing therethrough; the fourth valve body 92 is arranged between the second valve body 4 and the slurry supply container 5, and the fourth valve body 92 is used to adjust the flow rate of the slurry passing therethrough.

[0081] The second valve body 4 can be closed according to the pressure value detected by the detection component instead of being closed based on the first preset time, so that the second valve body 4 can be closed in time, thereby improving the efficiency of the system.

[0082] S104, pre-coating is performed, and the first valve body 2 remains in the open state for a fourth preset time. The fourth preset time can be adjusted according to the length of the flow channel in the coating die 3. The fourth preset time is 1s-10s. Preferably, the fourth preset time is 1 second. When the slurry begins to flow in the flow channel in the coating die 3, the slurry in different flow channels in the coating die 3 is unevenly distributed, which will cause poor uniformity when the coating die 3 starts coating. In order to improve the uniformity of the slurry coating on the surface of the substrate 7, pre-coating will be performed before the formal coating of the substrate 7 begins. During the pre-coating, the coating die 3 will discharge a predetermined amount of slurry, so that the slurry continues to flow in the coating die 3 for a period of time and evenly fills the coating die 3, and the slurry discharged from the coating die 3 is more uniform. During pre-coating, if the amount of slurry discharged from the coating die 3 is too small, there will still be uneven parts in the slurry in the coating die 3, affecting the subsequent coating quality. The first valve body 2 remains in the open state for the fourth preset time to ensure that the coating die 3 discharges slurry with uniform pressure. After the first valve body 2 remains in the open state for the fourth preset time, the first valve body 2 is closed to promptly block the slurry from continuing to be input into the coating die head 3, so as to avoid the formation of an uneven thickness area on the substrate 7. At the same time, the second valve body 4 is opened in advance by the seventh preset time based on the time node of closing the first valve body 2. The seventh preset time is between 0.05s and 0.2s. Preferably, the seventh preset time is 0.1s. Within the seventh preset time, the first valve body 2 and the second valve body 4 are both in the open state to divert the slurry with uniform pressure transported outward by the coating pump 1, so as to avoid the sudden closure of the first valve body 2. The slurry with uniform pressure transported outward by the coating pump 1 accumulates in the pipeline between the second valve body 4 and the coating pump 1, and accumulates in the pipeline between the first valve body 2 and the coating pump 1, so that the pressure in the area increases, affecting the life of the coating system. In an alternative implementation, the second valve body 4 is opened after the seventh preset time based on the time node of closing the first valve body 2. Step S104 may be performed once or multiple times to reduce the uneven portion of the slurry coated on the substrate 7. Of course, step S104 may not be performed.

[0083] S105, coating is performed, the coating system also includes a translational drive component, the translational drive component is connected to the coating die 3, the translational drive component can drive the coating die 3 to move along a second direction, the second direction is a direction extending along the length of the substrate 7, so that the coating die 3 scans the substrate 7; in a replaceable embodiment, the translational drive component is connected to the substrate 7, the translational drive component can drive the substrate 7 to move along a first direction, the first direction is a direction extending along the length of the substrate 7.

[0084] Execute step S102 to adjust the distance between the output end of the coating die head 3 and the substrate 7. Of course, if the distance between the output end of the coating die head 3 and the substrate 7 during pre-coating is consistent with that during coating, the following operation can also be performed directly: close the second valve body 4, and the translation drive member is opened in advance based on the time node of closing the second valve body 4 to avoid the accumulation of the coated slurry in the same area of ​​the substrate 7 when the translation drive member is opened later, resulting in uneven coating areas on the substrate 7. Of course, the translation drive member can also be opened after a fifth preset time, and the first valve body 2 is opened based on the closing of the second valve body 4. 4 is opened in advance of the eighth preset time, the eighth preset time is 0.05s-0.2s, preferably, the eighth preset time is 0.1s, in a replaceable implementation, the first valve body 2 is opened after the eighth preset time based on the time node of closing the second valve body 4; after the first valve body 2 is opened, the coating die 3 coats the slurry with uniform pressure on the substrate 7, and coats it sequentially along the length extension direction of the substrate 7 until the coating length of the coating die 3 reaches the set value, that is, the slurry layer on the substrate 7 reaches the set value, at this time, it is necessary to stop coating.

[0085] In an alternative implementation, after executing step S103, step S105 is directly executed without executing step S104, that is, the pre-coating operation is not performed, for example, after a coating break.

[0086] Specifically, step S200 includes:

[0087] S201, reflow the slurry transported outward during the stop time of the coating pump 1. The coating pump 1 has a stop time, and the stop time of the coating pump 1 is 0.05s-0.2s. Preferably, the stop time of the coating pump 1 is 0.2s. During the stop time, the pressure of the slurry output outward by the coating pump 1 has a process of gradually decreasing to zero. Therefore, during the stop time of the coating pump 1, the pressure of the slurry output outward by the coating pump 1 is uneven, and after the stop time, the coating pump 1 does not continue to transport the slurry outward.

[0088] The first valve body 2 is closed to promptly block the slurry from continuing to be input into the coating die head 3, thereby avoiding the formation of an uneven thickness area on the substrate 7. At the same time, the second valve body 4 is opened in advance by a third preset time based on the time node of closing the first valve body 2. Preferably, the third preset time is 0.1s. Within the third preset time, the first valve body 2 and the second valve body 4 are both in an open state to divert the slurry with uniform pressure delivered to the outside by the coating pump 1, thereby avoiding the sudden closure of the first valve body 2. The slurry with uniform pressure delivered to the outside by the coating pump 1 accumulates in the pipeline between the second valve body 4 and the coating pump 1, and accumulates in the pipeline between the first valve body 2 and the coating pump 1, so that the pressure in the area increases, affecting the life of the coating system. In an alternative implementation, the second valve body 4 is opened after a third preset time based on the time node of closing the first valve body 2.

[0089] S202, after the second valve body 4 remains in the open state for the eighth preset time, the coating pump 1 is turned off. Preferably, the eighth preset time is 0.1s. The eighth preset time is used to ensure that the coating pump 1 is turned off after the first valve body 2 is closed. After the second valve body 4 remains in the open state for the ninth preset time, the second valve body 4 is closed. The ninth preset time is greater than the stop time of the coating pump 1 to ensure that all the slurry within the stop time of the coating pump 1 flows back into the slurry supply container 5. The ninth preset time may also be greater than zero and less than the stop time of the coating pump 1, so that part of the slurry within the stop time of the coating pump 1 flows back into the slurry supply container 5. Preferably, the ninth preset time is 0.3s, and the stop time of the coating pump 1 is 0.2s to stop coating.

[0090] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A coating system, characterized in that: Including delivery branch and return branch; The delivery branch comprises a coating pump (1), a first valve body (2) and a coating die head (3); the reflux branch comprises the coating pump (1), a second valve body (4) and a slurry supply container (5); The output end of the coating pump (1) is connected to one end of the first valve body (2), and the other end of the first valve body (2) is connected to the input end of the coating die head (3); the output end of the coating pump (1) is connected to one end of the second valve body (4), and the other end of the second valve body (4) is connected to the slurry supply container (5).

2. The coating system according to claim 1, characterized in that: The invention also comprises a slurry supply branch, which comprises the slurry supply container (5), a third valve body (6) and the coating pump (1); the slurry supply container (5) is connected to one end of the third valve body (6), and the other end of the third valve body (6) is connected to the input end of the coating pump (1).

3. The coating system according to claim 1 or 2, characterized in that: It also comprises a substrate (7), wherein the substrate (7) is located below the output end of the coating die head (3), and the distance between the substrate (7) and the output end of the coating die head (3) is a first preset value.

4. The coating system according to claim 3, characterized in that: Also includes: A lifting drive member, the lifting drive member being connected to the coating die head (3), and the lifting drive member being capable of driving the coating die head (3) away from or close to the substrate (7); A translational drive member, wherein the translational drive member is connected to the substrate (7) or the coating die head (3), and the translational drive member can drive the substrate (7) to move along a first direction, or the translational drive member can drive the coating die head (3) to move along a second direction.

5. The coating system according to claim 4, characterized in that: Also includes: A detection member (91) is arranged between the coating pump (1) and the first valve body (2) and is used to obtain a pressure value of the slurry passing therethrough; The fourth valve body (92) is arranged between the second valve body (4) and the slurry supply container (5), and the fourth valve body (92) is used to adjust the flow rate of the slurry passing therethrough.

6. A coating method, characterized in that: The coating system provided in any one of claims 1 to 5, wherein the coating method comprises: When coating is required, the second valve body (4) is opened, and the coating pump (1) is turned on, the second valve body (4) remains in the open state for a first preset time, and then the second valve body (4) is closed, and the first valve body (2) is opened in advance or after a second preset time based on the time node of closing the second valve body (4); When it is necessary to stop coating, the first valve body (2) is closed, and the second valve body (4) is opened in advance or after a third preset time based on the time node of closing the first valve body (2).

7. The coating method according to claim 6, characterized in that: After the first valve body (2) is opened in advance or after a second preset time based on the time node of closing the second valve body (4), the method further includes: The first valve body (2) remains in the open state for a fourth preset time.

8. The coating method according to claim 7, characterized in that: It also comprises a base plate (7) and a lifting drive member, wherein the lifting drive member is connected to the coating die head (3), and the base plate (7) is located below the output end of the coating die head (3); Before the first valve body (2) is opened in advance or after a second preset time based on the time node of closing the second valve body (4), the step further includes: The lifting drive member is turned on, and the drive member drives the coating die head (3) to move away from or closer to the substrate (7), so that the distance between the output end of the coating die head (3) and the substrate (7) is a first preset value.

9. The coating method according to claim 8, characterized in that The device further comprises a translation driving member, wherein the translation driving member is connected to the substrate (7) and / or the coating die head (3); the translation driving member is capable of driving the substrate (7) to move along a first direction and / or the translation driving member is capable of driving the coating die head (3) to move along a second direction; After the step of closing the second valve body (4), before the step of opening the first valve body (2) in advance or after a second preset time based on the time node of closing the second valve body (4), the method further comprises: The translation driving member is opened in advance or after a fifth preset time based on a time node of closing the second valve body (4).

10. The coating method according to claim 9, characterized in that: It also comprises a slurry supply branch, the slurry supply branch comprises the slurry supply container (5), a third valve body (6) and the coating pump (1), the slurry supply container (5) is connected to one end of the third valve body (6), and the other end of the third valve body (6) is connected to the input end of the coating pump (1); When the coating pump (1) needs to absorb slurry, the third valve body (6) is opened, the coating pump (1) is turned on, the third valve body (6) remains in the open state for a sixth preset time, the coating pump (1) is turned off, and the third valve body (6) is closed at the same time.

Images