Composite trough for gravure roller type coating

Abstract

The utility model relates to a composite trough for gravure roller type coating, which comprises a trough main body, spiral stirrers extending along the length direction of the trough main body are respectively arranged on two sides in the trough main body, and the spiral stirrers are used for stirring slurry in the trough main body; during working, the two spiral stirrers are positioned below the liquid level of slurry in the trough main body; two ultrasonic vibration plates are symmetrically arranged at the bottom of the trough body in the length direction of the trough body. And the two spiral stirrers and the two ultrasonic vibration plates are controlled by the comprehensive control cabinet. The composite trough provided by the utility model can effectively ensure the uniformity and the consistency of slurry in the coating process, particularly has a remarkable improvement effect on the coating of volatile or settleable slurry, greatly improves the quality stability and the uniformity of a coated product, is not limited to be used for the primary coating of a positive current collector of a lithium battery, and has a good application prospect. And the gravure roller type coating device is also suitable for gravure roller type coating of other easily volatile or easily settled materials.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of gravure coating, and particularly to a compound trough for gravure roll coating. BACKGROUND

[0002] Gravure roll coating is a technical means for transferring slurry to the surface of a specific substrate by a screen roller. The gravure coating technology has the characteristics of contact coating, reverse coating, stable coating, and high repeatability. The gravure coating technology is widely used in the preparation of photovoltaic backsheet weather-resistant materials, anti-counterfeiting films, polymer conductive coatings, lithium ion battery separator coatings, and lithium battery current collector primers. The slurry used in gravure coating is basically a mixture of solvents, adhesives, special materials, and additives. The solvents in the slurry are volatile. Maintaining the uniform mixing of the materials in the slurry and the relative stability of the liquid and solid contents during the coating process has an important influence on the uniformity of the coating and the performance of the coating. For example, before the preparation of the positive electrode sheet of a lithium ion battery, a conductive carbon layer is often coated on the aluminum foil current collector to improve the interface properties, reduce the internal resistance, and improve the electrical performance of the battery. The conductive carbon layer is currently prepared by mixing conductive agents, solvents, deionized water, adhesives, and additives, and then coating the mixture onto the positive and negative surfaces of the aluminum foil using a gravure roller.

[0003] In the process of coating the conductive carbon layer on the positive electrode current collector, the slurry mixed and stirred in the slurry preparation workshop is transported to the coating workshop through a pipeline, directly introduced into a trough, or introduced into a trough through a transfer tank. However, the conventional troughs in the prior art have simple structures and single functions, which leads to problems such as easy precipitation and solvent evaporation of the slurry. Especially for slurry with easy sedimentation or easy evaporation formula, the consistency of the to-be-coated slurry is seriously affected, which further causes problems such as the uniformity and surface density consistency of the carbon layer. SUMMARY

[0004] The utility model aims at providing a compound trough for gravure roll coating, which effectively solves the problems raised in the background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical scheme.

[0006] A compound trough for gravure roll coating, comprising a trough body, two spiral mixers are arranged inside the trough body on both sides along the length direction of the trough body, for stirring the slurry in the trough body; during operation, the two spiral mixers are located below the liquid level of the slurry in the trough body; two ultrasonic vibration plates are symmetrically arranged on the bottom of the trough body along the length direction of the trough body; the two spiral mixers and the two ultrasonic vibration plates are controlled by a comprehensive control cabinet; a monitoring module is further arranged on the trough body, for monitoring the liquid level and viscosity of the slurry in the trough body; a slurry supply pipeline is arranged on one side of the trough body, and a solvent supply pipeline is arranged on the other side.

[0007] Further, two sides above the trough body are respectively provided with cover plates through supports, both cover plates extend along the length direction of the trough body; the opening for the passage of the coating plate roller is formed between the two cover plates.

[0008] Further, the monitoring module comprises a viscosity meter and a liquid level meter; the viscosity meter is installed on one of the cover plates, the liquid level meter is installed on the other cover plate, the collection ends of the viscosity meter and the liquid level meter extend into the trough body; the viscosity meter and the liquid level meter are electrically connected to the comprehensive control cabinet.

[0009] Further, the slurry supply pipeline and the solvent supply pipeline are both provided with electromagnetic valves, and both electromagnetic valves are controlled by the comprehensive control cabinet; a filter screen is arranged at the pipe opening of the slurry supply pipeline.

[0010] Further, a slurry outlet pipeline is arranged at the middle of the bottom of the trough body, an electromagnetic valve controlled by the comprehensive control cabinet is arranged in the slurry outlet pipeline, and a stop block is arranged on the pipe opening of the slurry outlet pipeline.

[0011] Further, both sides of the screw stirrer in the trough body, which are close to the middle of the trough body, are both provided with in-trough baffles, both in-trough baffles extend along the length direction of the trough body; a plurality of n-shaped holes are arranged in an array along the length direction of both in-trough baffles.

[0012] Further, the screw stirrer comprises a stirring main shaft with spiral blades and a driving motor; the stirring main shaft is rotatably installed in the trough body, and the driving motor is fixedly installed at the side of the trough body; the output shaft of the driving motor is fixedly connected with one end of the stirring main shaft.

[0013] Compared with the prior art, the utility model has the advantages as follows.

[0014] The composite trough provided by the utility model can realize real-time monitoring of the state of the to-be-coated slurry through the viscosity meter and the liquid level meter, the slurry replenishment channel and the solvent supply channel are arranged on the trough body, and the screw stirrer and the ultrasonic vibration plate are arranged, the screw stirrer and the ultrasonic vibration plate are controlled by the comprehensive control cabinet program to realize continuous and slow stirring and dispersion of the to-be-coated slurry, prevent the to-be-coated slurry from settling, and the program sets an early warning mechanism for liquid level and viscosity monitoring, and the slurry and the solvent are timely replenished and stirred uniformly under the linkage control, the coverage of the cover plates can effectively reduce the solvent volatilization caused by the exposure of the liquid surface, and the composite trough has good stable coating effect on the volatile or easily-settled slurry, the program linkage control can realize the functions of timely replenishing the solvent, replenishing the slurry, stirring and dispersing, and recycling the slurry, and effectively ensure the uniformity and consistency of the to-be-coated slurry in the trough, so that the composite trough is not limited to be used for the bottom coating of the lithium battery positive current collector, and can be applied to the gravure roller coating of other volatile or easily-settled materials. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a whole structure perspective view one of the utility model;

[0016] Figure 2 is a whole structure perspective view two of the utility model;

[0017] Figure 3 is a trough main part bottom partial structure schematic view in the utility model;

[0018] Figure 4 is Figure 1 plane schematic view one;

[0019] Figure 5 is Figure 1 plane schematic view two;

[0020] Figure 6 is a spiral agitator detailed structure schematic view in the utility model;

[0021] Figure 7 is a groove baffle structure schematic view in the utility model;

[0022] Figure 8 is the electric connection structure schematic view of the utility model. DETAILED DESCRIPTION

[0023] Please refer to Figures 1-8 The utility model provides a kind of composite trough for gravure roll type coating, including trough main body 1, cover plate 2, slurry supply pipeline 3, solvent supply pipeline 4, slurry outlet pipeline 5, spiral agitator 6, stirring spindle 61, spiral blade 62, driving motor 63, ultrasonic vibration plate 7, viscometer 8, liquid level meter 9, groove baffle 10, n-shaped hole 101, stop block 11, sliding seat 12, filter screen 13 and comprehensive control cabinet 14, wherein, cover plate 2 is made of transparent resin material, trough main body 1 body, stirring spindle 61 and spiral blade 62, groove baffle 10, each inlet and outlet pipeline, stop block 11 etc. Non-electric components are made of stainless steel material.

[0024] The technical scheme in the embodiments of the utility model will be described clearly and completely in conjunction with the drawings in the embodiments of the utility model below, obviously, the described embodiments only part of the embodiments of the utility model, not all embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor are within the scope of the utility model protection.

[0025] In the description of the embodiments of the utility model, it needs to be explained that, unless there is explicit provision and limitation, the terms, "connection", "installation" should be understood in a broad sense, for example, "connection" can be detachable connection, also can be inseparable connection, can be direct connection, also can be indirect connection through intermediate medium. In addition, "communication" can be direct communication, also can be indirect communication through intermediate medium. Among them, "fixing" refers to the relative position relationship of each other after connection and does not change. The orientation language mentioned in the embodiments of the utility model, for example, "inner", "outer", "top", "bottom" and the like, is only the direction of reference drawing, therefore, the orientation language used is for better, more clearly illustrate and understand the embodiments of the utility model, and is not indicated or implied that the device or element indicated must have a particular orientation, structure and operation in a particular orientation, therefore, it can not be understood as the limitation of the embodiments of the utility model.

[0026] In the embodiments of the utility model, the terms "first", "second" are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more features.

[0027] The top middle of the two short side of the main body 1 is provided with two lower concave arcs (not indicated in the drawing), which reserves space for the neck of the coating roll, so that the coating roll can be immersed into the main body 1, and the inner wall of the main body 1 is provided with a holder (not indicated in the drawing) for mounting the cover plate 2.

[0028] The cover plate 2 is mounted on the upper side of the main body 1 through the holder, and the two cover plates 2 extend along the length direction of the main body 1, the two cover plates 2 are used for covering the top of the main body 1, and the opening between the two cover plates 2 is designed to be slightly larger than the diameter of the coating roll (5-10mm), which can prevent splashing caused by the rotation of the coating roll and effectively reduce the solvent evaporation, and the cover plate 2 is made of transparent resin material, which is convenient for observing the working condition in the tank.

[0029] In addition, the bottom of the main body 1 is provided with two sliding seats 12 for mounting the tank, the coating roll is fixed, the tank is mounted on the lifting bracket through the two sliding seats 12, and the immersion and separation of the coating roll are realized.

[0030] The slurry supply pipeline 3 is connected with a material inlet of the transfer tank (not shown in the figure) and is used for feeding and supplementing the slurry. The slurry supply pipeline 3 is provided with a filter screen 13 at a pipe opening of the slurry supply pipeline 3, and the filter screen 13 is used for filtering the agglomerates or sundries. The solvent supply pipeline 4 is connected with a solvent delivery pipe (not shown in the figure) and is used for timely supplementing the solvent during the evaporation of the solvent.

[0031] The slurry supply pipeline 3 is connected with a material inlet of the transfer tank (not shown in the figure) and is used for feeding and supplementing the slurry. The slurry supply pipeline 3 is provided with a filter screen 13 at a pipe opening of the slurry supply pipeline 3, and the filter screen 13 is used for filtering the agglomerates or sundries. The solvent supply pipeline 4 is connected with a solvent delivery pipe (not shown in the figure) and is used for timely supplementing the solvent during the evaporation of the solvent.

[0032] The slurry supply pipeline 3 is connected with a material inlet of the transfer tank (not shown in the figure) and is used for feeding and supplementing the slurry. The slurry supply pipeline 3 is provided with a filter screen 13 at a pipe opening of the slurry supply pipeline 3, and the filter screen 13 is used for filtering the agglomerates or sundries. The solvent supply pipeline 4 is connected with a solvent delivery pipe (not shown in the figure) and is used for timely supplementing the solvent during the evaporation of the solvent.

[0033] The slurry supply pipeline 3 is connected with a material inlet of the transfer tank (not shown in the figure) and is used for feeding and supplementing the slurry. The slurry supply pipeline 3 is provided with a filter screen 13 at a pipe opening of the slurry supply pipeline 3, and the filter screen 13 is used for filtering the agglomerates or sundries. The solvent supply pipeline 4 is connected with a solvent delivery pipe (not shown in the figure) and is used for timely supplementing the solvent during the evaporation of the solvent.

[0034] The inner side of the trough body 1 near the spiral agitator 6 is provided with an inner baffle 10, and the two inner baffles 10 extend along the length direction of the trough body 1 to reduce the influence of liquid flow fluctuation caused by stirring on coating. The two inner baffles 10 are provided with a plurality of n-shaped holes 101 arranged in an array along the length direction of the inner baffles 10, and at least nine n-shaped holes 101 are arranged on one inner baffle 10 for mutual flow of slurry on both sides of the inner baffle 10.

[0035] The spiral agitator 6 includes an agitator main shaft 61 provided with a spiral blade 62 on the outside and a driving motor 63. The agitator main shaft 61 is rotatably installed in the trough body 1, and the driving motor 63 is fixedly installed on the side of the trough body 1. The output shaft of the driving motor 63 is fixedly connected with one end of the agitator main shaft 61. When the driving motor 63 works, the output shaft drives the agitator main shaft 61 and the spiral blade 62 to rotate, so as to achieve the purpose of stirring the slurry in the trough body 1.

[0036] The comprehensive control cabinet 14 is connected with the viscometer 8, the liquid level meter 9, the spiral agitator 6, the ultrasonic vibration plate 7, the electromagnetic valve in the slurry supply pipeline 3, the electromagnetic valve in the solvent supply pipeline 4, and the electromagnetic valve in the slurry outlet pipeline 5 in the trough body 1. In order to ensure the normal and continuous operation of coating, the related programs are set in the comprehensive control cabinet 14, and the control logic is “real-time monitoring, setting early warning, advance supply, and timely stirring”. The specific linkage working mode is as follows:

[0037] When the liquid level meter 9 and the viscometer 8 are both normal, the comprehensive control cabinet 14 controls the spiral agitator 6 to enter the lowest speed mode and the ultrasonic vibration plate 7 to enter the lowest emission power mode, so as to continuously stir and disperse the slurry in the trough body 1.

[0038] Under the premise of ensuring that the liquid surface immerses the spiral agitator 6, the liquid level warning line is set according to the degree of the plate roller immersed in the slurry. When the liquid level meter 9 monitors that the liquid level approaches the set warning line, the comprehensive control cabinet 14 controls the electromagnetic valve in the slurry supply pipeline 3 to be opened to supply slurry to the trough body 1. At the same time, the program linkage controls the spiral agitator 6 to speed up and the ultrasonic vibration plate 7 to increase the power, so as to simultaneously stir and disperse the newly incoming slurry and the slurry in the trough body 1. When the liquid level reaches above the warning line, the program closes the electromagnetic valve in the slurry supply pipeline 3, and controls the spiral agitator 6 to restore the lowest speed and the ultrasonic vibration plate 7 to restore the lowest emission power.

[0039] The monitoring and replenishment of viscosity adopts an early warning and early replenishment mechanism (solvent is replenished only when the viscosity exceeds the upper limit of the process), and according to the requirements of coating viscosity, a pre-warning value when approaching the upper limit of the process is set. When the viscosity meter 8 monitors the slurry viscosity to reach the pre-warning value, the program control of the comprehensive control cabinet 14 opens the electromagnetic valve in the solvent replenishment pipeline 4 to replenish the solvent into the main body 1 of the tank, and simultaneously controls the screw stirrer 6 to speed up and the ultrasonic vibration plate 7 to increase the power, so as to stir and disperse the newly added solvent and the slurry in the main body 1 of the tank. Since the viscosity monitoring will be slightly delayed compared with the stirring and dispersion effect, in order to prevent the slurry viscosity from being too low due to excessive solvent replenishment, the solvent replenishment adopts an intermittent mechanism, that is, the electromagnetic valve in the solvent replenishment pipeline 4 is controlled to be opened for 5-10 seconds and then closed, and the stirring and dispersion is controlled for 5 minutes and then the viscosity is monitored. If the viscosity is still not reduced below the pre-warning value, the electromagnetic valve in the solvent replenishment pipeline 4 is opened again for 5-10 seconds and then closed, and the stirring and dispersion is controlled for 5 minutes and then the viscosity is monitored. This intermittent process continues until the viscosity monitored by the viscosity meter 8 is reduced below the pre-warning value, and then the program closes the intermittent replenishment of the solvent and controls the screw stirrer 6 to return to the minimum speed and the ultrasonic vibration plate 7 to return to the minimum transmission power.

[0040] After coating for a longer time, it is still difficult to avoid that part of the slurry is settled at the bottom of the tank. The program of the comprehensive control cabinet 14 is set to open the electromagnetic valve in the slurry outlet pipeline 5 every 24 hours to pump the thick slurry at the bottom of the main body 1 of the tank back to the transfer tank, which is then reused after being stirred and dispersed in the transfer tank. While pumping back the slurry, the program of the comprehensive control cabinet 14 is linked to control the electromagnetic valve in the slurry replenishment pipeline 3 to be opened to replenish the slurry, so as to keep the liquid level in the main body 1 of the tank basically unchanged. At the same time, the screw stirrer 6 is controlled to speed up and the ultrasonic vibration plate 7 is controlled to increase the power. After the program is executed for 10-15 minutes, the program controls the slurry to stop flowing out and being replenished, and the screw stirrer 6 and the ultrasonic vibration plate 7 continue to operate at high speed for 5-10 minutes and then return to the minimum speed and the minimum transmission power.

[0041] The composite tank monitors the state of the slurry to be coated in real time by setting the viscosity meter 8 and the liquid level meter 9. The main body 1 of the tank is provided with a slurry replenishment channel and a solvent replenishment channel, as well as a screw stirrer 6 and an ultrasonic vibration plate 7. The screw stirrer 6 and the ultrasonic vibration plate 7 are controlled by the program of the comprehensive control cabinet 14 to realize continuous and slow stirring and dispersion of the slurry to be coated, and to prevent settlement. In addition, the program is set to have an early warning mechanism for liquid level and viscosity monitoring, and to link the control of timely replenishment of the slurry and the solvent and stirring after replenishment. The covering of the cover plate 2 can also effectively reduce the solvent evaporation caused by the exposure of the liquid surface. For volatile or easily settled slurry, the cover plate 2 has a good stable coating effect. By setting the program link control, the functions of timely replenishing the solvent, replenishing the slurry, stirring and dispersion, and recycling the slurry are realized, which effectively ensures the uniformity and consistency of the slurry to be coated in the tank, so that the application is not limited to the bottom coating of the lithium battery positive electrode current collector, but can also be applied to the gravure roll coating of other volatile or easily settled materials.

[0042] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the application can be implemented in other particular forms without departing from the spirit or essential characteristics of the application. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No feature of the application is considered critical unless it is expressly stated in the claims.

Claims

1. A compound tank for gravure roll coating, comprising a tank body (1), characterized in that: both sides of the tank body (1) are provided with helical mixers (6) extending along the length direction of the tank body (1) for mixing slurry in the tank body (1); both helical mixers (6) are located below the liquid level of the slurry in the tank body (1) during operation; two ultrasonic vibration plates (7) are symmetrically arranged at the bottom of the tank body (1) along the length direction of the tank body (1); both helical mixers (6) and both ultrasonic vibration plates (7) are controlled by a comprehensive control cabinet (14); a monitoring module is further arranged on the tank body (1) for monitoring the liquid level and viscosity of the slurry in the tank body (1); a slurry supply pipeline (3) is arranged on one side of the tank body (1), and a solvent supply pipeline (4) is arranged on the other side of the tank body (1).

2. The compound tank for gravure roll coating according to claim 1, characterized in that: both sides of the tank body (1) are provided with cover plates (2) through supports, both cover plates (2) extend along the length direction of the tank body (1); an opening for the passage of a coating roll is formed between the two cover plates (2).

3. The compound tank for gravure roll coating according to claim 2, characterized in that: the monitoring module comprises a viscometer (8) and a liquid level meter (9); the viscometer (8) is installed on one of the cover plates (2), the liquid level meter (9) is installed on the other cover plate (2), the collection ends of the viscometer (8) and the liquid level meter (9) extend into the tank body (1); the viscometer (8) and the liquid level meter (9) are electrically connected to the comprehensive control cabinet (14).

4. The compound tank for gravure roll coating according to claim 1, characterized in that: both the slurry supply pipeline (3) and the solvent supply pipeline (4) are provided with solenoid valves, and both solenoid valves are controlled by the comprehensive control cabinet (14); a filter screen (13) is arranged at the pipe opening of the slurry supply pipeline (3).

5. The compound tank for gravure roll coating according to claim 1, characterized in that: a slurry outlet pipeline (5) is arranged at the middle of the bottom of the tank body (1), a solenoid valve controlled by the comprehensive control cabinet (14) is installed in the slurry outlet pipeline (5), and a stop block (11) is arranged at the pipe opening of the slurry outlet pipeline (5).

6. The compound tank for gravure roll coating according to claim 1, characterized in that: both sides of the tank body (1) are provided with inner tank baffles (10) located towards the middle of the tank body (1) relative to the helical mixers (6), both inner tank baffles (10) extend along the length direction of the tank body (1); a plurality of n-shaped holes (101) are arrayed along the length direction of both inner tank baffles (10).

7. The compound tank for gravure roll coating according to claim 1, characterized in that: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The screw stirrer (6) comprises a stirring spindle (61) with screw blades (62) on the outside and a drive motor (63); The stirring spindle (61) is rotatably installed in the trough body (1), and the drive motor (63) is fixedly installed on the side of the trough body (1); The output shaft of the drive motor (63) is fixedly connected with one end of the stirring spindle (61).

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