A method of coating aluminum foil

Abstract

The present application belongs to the technical field of carbon-coated aluminum foil, and particularly relates to a method for coating the appearance of aluminum foil. The carbon-coating device for aluminum foil comprises a trough (3), an ink transfer roller (1) and a plate roller (2). The outer peripheral surface of the ink transfer roller (1) is at least partially located in the slurry (4) in the trough (3), and the outer peripheral surface of the ink transfer roller (1) is provided with mesh holes, which include honeycomb-shaped holes and through grooves connecting the honeycomb-shaped holes. The carbon-coated foil made by using the ink transfer roller with mesh holes on the surface can significantly reduce the bubble leakage and poor coating rate, has excellent carbon-coated appearance, and can improve the consistency and performance of the product.

Description

Technical Field

[0001] This invention belongs to the field of carbon-coated aluminum foil technology, and specifically relates to an aluminum foil coating method. Background Technology

[0002] The existing coating method for carbon-coated aluminum foil production is gravure printing transfer coating. Commonly used coating material carrying methods include: Method 1, which involves directly immersing the printing roller in the material tank and slurry to carry the material; and Method 2, which uses a traditional rubber inking roller device to transfer and carry the material, i.e., immersing the inking roller in the material tank to carry the material, and then transferring the material to the printing roller through the inking roller.

[0003] Existing material feeding methods and processes have defects and shortcomings: In Method 1, the printing roller is directly immersed in the material tank and rotates, which causes the slurry to be agitated at a high frequency, which easily generates air bubbles and causes coating defects such as missed coating on the printing plate; In Method 2, due to the smooth surface of the ink roller, it is easy to have problems with insufficient material feeding and uneven material feeding, which will produce air bubbles or missed coating.

[0004] This application is submitted in order to address the above issues. Summary of the Invention

[0005] This application designs an ink delivery roller with a surface engraved with a mesh shape. By uniformly arranging the mesh on the surface of the ink delivery roller, the material carrying capacity and uniformity are increased. At the same time, the ink delivery roller device of this application is equipped with a high-frequency variable frequency servo motor, which can reach a maximum speed of 100 rpm. The high-speed rotation increases the uniformity of the material carrying. In addition, the device can adjust the gap between the ink delivery roller and the printing roller 2 to squeeze and break the foam in the slurry 4, achieving a good defoaming effect.

[0006] This application provides an aluminum foil carbon coating device, which includes: a material tank 3, an ink delivery roller 1, and a printing roller 2;

[0007] Wherein, the outer peripheral surface of the ink-dispensing roller 1 is at least partially located in the slurry 4 of the material trough 3, and the outer peripheral surface of the ink-dispensing roller 1 is provided with mesh holes;

[0008] The mesh includes: honeycomb-shaped holes and through channels connecting the honeycomb-shaped holes.

[0009] The printing roller 2 is installed above the ink delivery roller 1 and is used to receive the ink transfer from the ink delivery roller 1.

[0010] Preferably, the ink delivery roller 1 is mounted on a variable frequency motor, and the variable frequency motor can adjust the gap between the ink delivery roller 1 and the printing roller 2 to squeeze and break the foam in the slurry 4;

[0011] Preferably, a through groove connects several honeycomb-shaped holes arranged at intervals, and several through grooves are arranged in parallel on the outer peripheral surface of the ink delivery roller 1.

[0012] Preferably, the depth of the mesh is 20-30 micrometers.

[0013] Preferably, the mesh is disposed in the coating area on the outer peripheral surface of the ink roller 1, and the honeycomb-shaped hole area accounts for 70-90% of the coating area.

[0014] A second aspect of this application provides an aluminum foil coating method that uses the aluminum foil carbon coating apparatus described in the first aspect;

[0015] The method includes the following steps: starting the variable frequency motor, the variable frequency motor drives the ink delivery roller 1 to rotate in the material trough 3, the slurry 4 in the material trough 3 enters the mesh on the outer peripheral surface of the ink delivery roller 1, the ink delivery roller 1 contacts the printing roller 2, and transfers the slurry 4 on the outer peripheral surface and in the mesh of the ink delivery roller 1 to the printing roller 2.

[0016] Preferably, the variable frequency motor drives the ink delivery roller 1 to move to change the gap between it and the printing roller 2, thereby squeezing and breaking the foam in the paste 4.

[0017] Preferably, the gap between the end of the ink delivery roller 1 and the end of the printing roller 2 is controlled to be 1-2 mm. The foam in the slurry 4 is squeezed into the mesh of the ink delivery roller 1 and bursts.

[0018] The third aspect of this application provides the use of the method of the second aspect for improving the coating quality of aluminum foil.

[0019] Compared with the prior art, this application has the following advantages:

[0020] 1. The present invention utilizes an ink-spreading roller with mesh-like surface to make a carbon coating foil, which can significantly reduce the rate of bubble-induced coating defects, produce an excellent carbon coating appearance, improve product consistency, and thus enhance product performance.

[0021] 2. Compared with traditional carbon-coated foil, the carbon-coated foil made by the present invention using an ink-spreading roller with mesh on the surface is more uniform and delicate, which can increase the contact area with the positive electrode active material lithium iron phosphate and enhance the peeling force.

[0022] 3. This invention utilizes an ink-dispensing roller with mesh-like surfaces, resulting in good fluidity of the slurry during application and excellent material carrying capacity. It is also easy to operate and has high production efficiency, which is conducive to achieving mechanized and large-scale production. Attached Figure Description

[0023] Figure 1 This is a schematic diagram showing the positions of ink delivery roller 1, printing roller 2, and material trough 3.

[0024] Figure 2This is a schematic diagram of the mesh structure on the outer peripheral surface of the ink delivery roller. Attached image description:

[0026] 1. Ink delivery roller, 2. Printing roller, 3. Material trough, 4. Slurry. Detailed Implementation

[0027] The present application will now be described in further detail with reference to the embodiments.

[0028] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with the techniques or conditions described in the literature in the field or according to the product manual. Materials or equipment whose manufacturers are not specified are all conventional products that can be obtained by purchase.

[0029] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the word “comprising” as used in this application's specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” to another element, it can be directly connected to the other element, or there may be intermediate elements. Furthermore, the term “connected” as used herein can include wireless connections.

[0030] In the description of this application, unless otherwise stated, "a plurality of" means two or more. The terms "inner," "upper," "lower," etc., indicate the orientation or state relationship based on the orientation or state relationship shown in the drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "equipped with" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this application according to the specific circumstances.

[0032] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0033] Example 1

[0034] An aluminum foil carbon coating device, the aluminum foil carbon coating device comprising: a material tank 3, an ink delivery roller 1, and a printing roller 2;

[0035] Wherein, the outer peripheral surface of the ink-dispensing roller 1 is at least partially located in the slurry 4 of the material trough 3, and the outer peripheral surface of the ink-dispensing roller 1 is provided with mesh holes;

[0036] The ink delivery roller 1 is mounted on a variable frequency motor, which can adjust the gap between the ink delivery roller and the printing roller 2 to squeeze and break the foam in the slurry 4.

[0037] The variable frequency motor can also adjust the rotational speed of the ink delivery roller 1.

[0038] The coating area on the outer peripheral surface of the ink roller 1 is provided with mesh.

[0039] An aluminum foil coating method includes the following steps:

[0040] a. Ink delivery roller design and manufacturing

[0041] A honeycomb pattern is designed on the coating area of ​​the ink roller surface, evenly distributed throughout the coating area, with the honeycomb pattern area accounting for 80% of the total coating area;

[0042] Each honeycomb cell is connected by a channel to create a mesh;

[0043] The ink rollers are manufactured according to the designed mesh, and two rollers of the same specification are produced.

[0044] b. Ink roller installation

[0045] Install the two prepared ink rollers onto the AB die head of the carbon coating machine.

[0046] c. Configure servo motors

[0047] A 50 rpm variable frequency servo motor is installed on the manufactured ink delivery roller. The variable frequency motor can adjust the gap between the ink delivery roller and the printing roller 2 to squeeze and break the foam in the slurry 4.

[0048] The speed of the variable frequency servo motor is controlled at 50 rpm to prevent damage to the ink delivery roller and foam in the ink slurry 4 if the speed is too high, and to prevent the ink slurry 4 from being transferred to the printing roller 2 if the speed is too low. The gap between the end of the ink delivery roller and the end of the printing roller 2 is 1.5 mm.

[0049] d. Pre-scraping

[0050] Immerse the ink roller in the coating and activate the doctor blade device. Perform pre-scraping at a speed of 20 meters per minute for 30 minutes. Observe that the doctor blade and the gravure roller 2 scrape the surface evenly, and the pre-scraping is completed.

[0051] e. Oven temperature rises, fan starts

[0052] Turn on the fan to raise the oven temperature. Set the temperature to 100℃, and the actual temperature reaches the set value.

[0053] f. Printing

[0054] Pressing is performed using pressure rollers at a startup speed of 35 meters per second.

[0055] Apply aluminum foil coating according to the method described above.

[0056] The texture depth is 25 micrometers. Solid content of slurry 4: 8%. Slurry 4 was purchased from Guangdong Bohai Chemical Technology Co., Ltd., batch code HG8002.

[0057] The specific dimensions of the ink delivery roller 1 are as follows: the maximum height A of the honeycomb holes is 1.5 mm, and the maximum width B of the honeycomb holes is 1.3 mm. The length C of the groove connecting two adjacent honeycomb holes is 3.52 mm, and the width of the groove is 0.3 mm. The distance D between two parallel honeycomb holes is 3.06 mm.

[0058] Example 2

[0059] The anilox depth of the ink roller 1 in Example 1 was changed from 25 micrometers to 20 micrometers. All other conditions remained unchanged.

[0060] Example 3

[0061] The anilox depth of the ink roller 1 in Example 1 was changed from 25 micrometers to 30 micrometers. All other conditions remained unchanged.

[0062] Comparative Example 1

[0063] The difference from Example 1 is that the printing roller 2 is directly immersed in the material tank 3, and the ink delivery roller is not used. All other conditions remain the same.

[0064] Comparative Example 2

[0065] The difference from Example 1 is that a conventional ink roller is used. This conventional ink roller was purchased from Shenzhen Yuncheng Printing Equipment Co., Ltd. All other conditions remain unchanged.

[0066] Table 1

[0067] Experimental group Bubble and missed coating rate Comparative Example 1 3.50％ Comparative Example 2 2.80％ Example 1 0.30％

[0068] Table 1 demonstrates that, compared to the cases of not using an inking roller and using a conventional inking roller, the defect rate of bubble-induced coating in this application is significantly reduced, from 3.50% to 0.30%. The reason why the foam in the paste 4 can be squeezed and broken is likely because the foam is squeezed into the weave of the inking roller, thus causing it to break. However, when using a conventional inking roller, the foam, after being squeezed, escapes from the gap between the conventional inking roller and the printing roller 2, and therefore does not break.

[0069] Comparative Example 3

[0070] Replace the ink delivery roller in Example 1 with a honeycomb-shaped, grooveless ink delivery roller. All other conditions remain unchanged.

[0071] The difference between the honeycomb-shaped non-grooved ink roller and the ink roller of Example 1 is that: no groove is provided to connect each honeycomb hole, only honeycomb holes are provided.

[0072] Comparative Example 4

[0073] Replace the ink delivery roller in Example 1 with a quadrilateral ink delivery roller with through grooves. Keep all other conditions unchanged.

[0074] The difference between the quadrilateral grooved ink roller and the ink roller of Example 1 is that each honeycomb hole is replaced with a regular quadrilateral hole.

[0075] Comparative Example 5

[0076] Replace the ink delivery roller in Comparative Example 4 with a quadrilateral ink delivery roller without through grooves. Keep all other conditions unchanged.

[0077] The difference between the quadrilateral ink roller with through-groove and the ink roller of Comparative Example 4 is that the quadrilateral ink roller does not have through-grooves connecting each quadrilateral hole.

[0078] Comparative Example 6

[0079] The anilox depth of the ink roller in Example 1 was replaced from 25 micrometers to 10 micrometers. All other conditions remained unchanged.

[0080] Comparative Example 7

[0081] The anilox depth of the ink roller in Example 1 was replaced from 25 micrometers to 15 micrometers. All other conditions remained unchanged.

[0082] Performance testing:

[0083] The performance of the carbon-coated aluminum foils obtained in Example 1 and Comparative Examples 2-5 was tested, and the results are shown in Table 2 below.

[0084] Table 2 shows that the ink roller with honeycomb-shaped through-groove mesh in Example 1 has excellent material carrying capacity and coating appearance.

[0085] The reason for the poor coating appearance of the non-channel ink transfer rollers in Comparative Examples 3 and 5 may be that the lack of channels easily leads to the slurry 4 being blocked in the honeycomb holes, affecting the transfer of slurry 4 to the printing roller 2.

[0086] The coating appearance of the quadrilateral grooved ink roller in Comparative Example 4 was poor. The reason may be that the carbon ink particles in slurry 4 are hexagonal. Hexagonal carbon ink particles are more compatible with honeycomb holes, resulting in a more regular arrangement of particles in the mesh. The mismatch between the hexagonal carbon ink particles and the quadrilateral hole shape leads to a messy arrangement of particles in the mesh, ultimately resulting in a poor coating appearance.

[0087] Table 2

[0088]

[0089]

[0090] The performance of the carbon-coated aluminum foils obtained in Examples 1-3 and Comparative Examples 6-7 was tested, and the results are shown in Table 3 below.

[0091] Table 3 explains that, for the required surface density of carbon-coated aluminum foil of 0.6 ± 0.1 g / m², Example 1 best meets the requirement. The surface densities of Examples 2 and 3 are not significantly different from those of Example 1.

[0092] Table 3

[0093]

Claims

1. An aluminum foil coating method characterized by, A carbon coating device for aluminum foil is used, which comprises a trough (3), an ink transfer roller (1) and a plate roller (2). The carbon coating device for aluminum foil comprises a trough (3), an ink transfer roller (1) and a plate roller (2). The outer circumferential surface of the ink transfer roller (1) is at least partially located in the slurry (4) in the trough (3), and the outer circumferential surface of the ink transfer roller (1) is provided with mesh holes, which comprise honeycomb-shaped holes and through grooves connecting the honeycomb-shaped holes. The ink transfer roller (1) is installed on a variable frequency motor, which can adjust the gap between the ink transfer roller (1) and the plate roller (2) to extrude and break the bubbles in the slurry (4). The method comprises the following steps: starting the variable frequency motor, the variable frequency motor drives the ink transfer roller (1) to rotate in the trough (3), the slurry (4) in the trough (3) enters the mesh holes on the outer circumferential surface of the ink transfer roller (1), the ink transfer roller (1) contacts the plate roller (2), and the slurry (4) in the mesh holes on the outer circumferential surface of the ink transfer roller (1) is transferred to the plate roller (2).

2. The method of claim 1, wherein, A through groove connects a plurality of honeycomb-shaped holes arranged at intervals, and a plurality of through grooves are arranged in parallel on the outer circumferential surface of the ink transfer roller (1).

3. The method of claim 1, wherein, The depth of the mesh hole is 20-30 microns.

4. The method of claim 1, wherein, The mesh hole is arranged in the coating area on the outer circumferential surface of the ink transfer roller (1), and the area of the honeycomb-shaped hole accounts for 70-90% of the area of the coating area.

5. Use of the method of any one of claims 1-4 for improving the coating quality of aluminum foil.

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