Electrostatic auxiliary coating pretreatment device compatible with single and double layer ultra-thin metal foil rolling

Abstract

This invention discloses an electrostatically assisted coating pretreatment device compatible with single and double-layer ultra-thin metal foil rolling. The invention employs a "Y"-shaped cavity design compatible with both single and double-layer paths, featuring a closed coating chamber with "Y"-shaped guiding characteristics. This simultaneously satisfies the "inner side closure coating" of double-layer foils and the "double-sided center coating" of single-layer foils. This invention effectively solves the limitation of traditional equipment in handling both single and double-layer processes. By simply changing the threading path, it seamlessly switches between the "double-layer overlay anti-rib mark mode" and the "single copper foil high-precision lubrication mode," achieving "dual-purpose use" and significantly improving equipment utilization. Simultaneously, the nanoscale uniform lubricating film formed by electrostatic targeted adsorption eliminates the "stickiness-slippage" physical jamming on the metal surface from the root of mechanical tribology, completely resolving the "double rib mark" and single-layer chatter defects of overlay rolling.

Description

Technical Field

[0001] This invention relates to the field of pretreatment technology for electrostatic coating applicable to single-layer rolling and double-layer stacking processes of ultra-thin copper foil, and in particular to an electrostatic assisted coating pretreatment device compatible with single and double-layer ultra-thin metal foil rolling. Background Technology

[0002] In the cold rolling production of extremely thin metal foils (such as copper foil and aluminum foil) with a thickness ≤10μm, the material in the roll meshing zone is subjected to extremely high compressive forces and undergoes intense plastic deformation and shear stress. To prevent direct microscopic contact between the metal and the rolls (avoiding cold welding or wear under mixed lubrication conditions), cold rolling oil must be used for lubrication and cooling. Currently, the industry typically uses mechanical roll coating or traditional spraying methods to apply rolling oil to the surface of the metal foil. Simultaneously, to overcome the physical limits of mill reduction at thicknesses ≤10μm, a "stack rolling" process is often employed, where two layers of extremely thin copper foil are overlapped and simultaneously passed through the mill.

[0003] However, existing lubrication and pretreatment equipment exhibits significant structural defects in actual production. Firstly, it is highly prone to "double rib marks" in the stacking rolling process. When two layers of copper foil are joined into the main rolling mill, traditional spraying or roll coating devices cannot guarantee absolute uniformity of the interlayer oil film at the nanoscale. Localized oil film deficiencies or uneven thickness lead to high-frequency "stick-slip" friction instability at the metal contact surface. Under the pressure of thousands of tons in the main rolling mill, this high-frequency mechanical shock wave will press periodic "double rib marks" or chatter marks onto the copper foil surface. Secondly, during single copper foil rolling, traditional oiling mechanisms struggle to achieve uniform coverage at the microscopic level, easily causing localized dry friction on the rolls, resulting in high-frequency chattering of the rolling mill and a decrease in the surface finish of the foil. Furthermore, traditional open-type high-pressure spraying equipment also causes severe oil splashing and waste, significantly increasing subsequent cleaning costs and environmental burden. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide an electrostatic assisted coating pretreatment device compatible with single and double-layer ultra-thin metal foil rolling.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: an electrostatic assisted coating pretreatment device compatible with single and double layer ultra-thin metal foil rolling, comprising an unwinding module, a single and double layer compatible electrostatic coating chamber, and a flexible guide pressing roller;

[0006] The unwinding module is located at the front end of the coating pretreatment device and is used to output ultra-thin metal foil with a thickness of ≤10μm. Two sets of tension control rollers are arranged symmetrically at the rear of the unwinding module.

[0007] The single- and double-layer compatible electrostatic coating chamber is equipped with a closed cavity. The front of the cavity has a feed inlet, and the rear of the cavity has a discharge slit. Multiple guide rollers are installed inside the cavity, and the tension control roller group is located in front of the feed inlet.

[0008] A Y-shaped guide is installed inside the cavity. The Y-shaped guide extends from the feed port to the middle and rear side of the cavity. A Y-shaped guide opening with a height that converges from the outside to the inside is provided on the front side of the cavity. Each guide roller abuts against the upper and lower surfaces of the Y-shaped guide, forming a Y-shaped guide path on the outside of the Y-shaped guide for guiding two layers of ultra-thin metal foil.

[0009] The maximum height on the left side of the Y-shaped guide is less than the height of the feed inlet. When guiding a single-layer ultra-thin metal foil, the Y-shaped guide exits through the feed inlet to the outside of the cavity.

[0010] Multiple atomizing nozzles that spray oil mist toward the center are spaced apart on the upper and lower sides of the cavity;

[0011] A flexible roller assembly is installed inside the cavity, and the flexible roller assembly is located near the discharge slit.

[0012] Furthermore, the Y-shaped guide has two symmetrically arranged metal foil guiding surfaces. From front to back, the metal foil guiding surfaces include a large inclined guiding surface, a horizontal guiding surface, and a small inclined guiding surface, all inclined towards the center of symmetry. The total distance between the front ends of the two large inclined guiding surfaces is less than the height of the feed inlet. The rear ends of the two small inclined guiding surfaces are connected, and the connection point of the two small inclined guiding surfaces is near the pressing point of the flexible roller assembly, which is used to guide the two extremely thin metal foils to physically close together.

[0013] Furthermore, the front end face of the Y-shaped guide is located inside the feed inlet, and guide rails and locking devices are respectively provided on both sides of the single and double layer compatible electrostatic coating chamber. The corresponding guide rails are slidably installed on both sides of the Y-shaped guide, and the locking devices are locked in place with the Y-shaped guide.

[0014] Furthermore, a movable cover plate is provided on the upper and lower sides of the feed inlet. After the Y-shaped guide exits the cavity, the two movable cover plates move symmetrically toward the center position and close the feed inlet, forming a feed gap between the upper and lower movable cover plates.

[0015] The height of the discharge slit and the feed slit is less than 0.5 cm;

[0016] A cold rolling roll is provided on the rear side of the discharge slot, and the cold rolling roll is located on the outside of the single and double layer compatible electrostatic coating chamber.

[0017] Furthermore, both sets of tension control rollers are equipped with magnetic powder brakes and tension sensors; the magnetic powder brakes are equipped with servo motors, which receive signals from the tension sensors and drive the tension control rollers using PID closed-loop control. The difference in mechanical tension between the two sets of tension control rollers is less than 10 N / m.

[0018] Furthermore, the unwinding module is equipped with two independently controlled roller lifting mechanisms, and the two tension control roller groups are respectively installed in the corresponding roller lifting mechanisms.

[0019] Furthermore, the end of the atomizing nozzle is electrically connected to a high-voltage electrostatic generator, the tension control roller group and the Y-shaped guide are grounded respectively, and a high-voltage electrostatic field with opposite directions is formed on the upper and lower sides of the ultra-thin metal foil. An ultrasonic transmission rod is installed at the end of the atomizing nozzle, and the ultrasonic transmission rod is connected to the ultrasonic generator.

[0020] The advantages of this invention compared to the prior art are:

[0021] 1. This invention adopts a "Y"-shaped cavity design that is compatible with both single and double-layer paths. It innovatively designs a closed coating chamber with "Y"-shaped guiding characteristics. Combined with an upper and lower symmetrical unwinding module with independent tension, the device can simultaneously meet the requirements of "inner side closure coating" for double-layer foil and "double-sided center coating" for single-layer foil through simple tape path switching.

[0022] 2. This invention introduces an electrostatic field directional adsorption coating mechanism, which sets up a high-voltage electrostatic generator and a micro-nano atomizing nozzle array in the chamber. It utilizes the physical principles of opposite charge attraction and electrostatic "encirclement effect" to perform non-contact, precise and uniform coating.

[0023] 3. This invention effectively solves the limitation of traditional equipment in handling both single and double-layer processes. It allows seamless switching between "double-layer lamination anti-rib mark mode" and "single copper foil high-precision lubrication mode" simply by changing the threading path, achieving "dual-purpose machine" and significantly improving equipment utilization. Simultaneously, the nanoscale uniform lubricating film formed by electrostatic targeted adsorption eliminates the "stickiness-slippage" physical jamming on the metal surface from the root of mechanical tribology, completely resolving the "double rib mark" and single-layer chatter defects in lamination.

[0024] 4. This invention relies on the directional adsorption effect of electrostatics combined with a closed cavity. This device completely eliminates oil splashing and waste, and significantly improves the production and environmental environment of the workshop. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of double-layer copper foil lamination.

[0026] Figure 2 This is a schematic diagram of a single-layer copper foil stacking structure.

[0027] 1. Tension control roller assembly.

[0028] 2. Single and double layer compatible electrostatic coating chamber

[0029] 21. Cavity 22. Feed inlet 23. Discharge slot 24. Guide roller 25. Feed slot

[0030] 3. Y-type guide.

[0031] 4. Atomizing nozzle.

[0032] 5. Flexible roller assembly.

[0033] 6. Movable cover plate.

[0034] 7. Cold rolling rolls. Detailed Implementation

[0035] An electrostatic assisted coating pretreatment device compatible with single and double-layer ultra-thin metal foil rolling. Figure 1 and 2 As shown, it includes an unwinding module, a single / double-layer compatible electrostatic coating chamber 2, and a flexible guide pressing roller; the unwinding module is located at the front end of the coating pretreatment device and is used to output ultra-thin metal foil with a thickness ≤10μm. Two sets of tension control roller groups 1 are arranged symmetrically at the top and bottom on the rear side of the unwinding module; the unwinding module is equipped with two sets of independently controlled roller lifting mechanisms, and the two sets of tension control roller groups 1 are respectively installed on the corresponding roller lifting mechanisms.

[0036] The single- and double-layer compatible electrostatic coating chamber 2 is provided with a closed cavity 21. The front side of the cavity 21 is provided with a feed inlet 22, and the rear side of the cavity 21 is provided with a discharge slit 23. The rear side of the discharge slit 23 is provided with a cold rolling roller 7, which is located on the outside of the single- and double-layer compatible electrostatic coating chamber 2.

[0037] Multiple atomizing nozzles 4 that spray oil mist toward the center are respectively arranged on the upper and lower sides of the cavity 21; a flexible roller assembly 5 is installed inside the cavity 21, and the flexible roller assembly 5 is adjacent to the discharge slit 23.

[0038] Multiple guide rollers 24 are installed inside the cavity 21, and the tension control roller group 1 is located at the front side of the feed inlet 22. A Y-shaped guide 3 is movably installed inside the cavity 21, extending from the feed inlet 22 to the middle and rear side of the cavity 21. The front side of the cavity 21 is provided with a Y-shaped guide opening that converges in height from the outside to the inside. Each guide roller 24 abuts against the upper and lower surfaces of the Y-shaped guide 3, forming a Y-shaped guide path on the outside of the Y-shaped guide 3 for guiding two layers of ultra-thin metal foil. The maximum height on the left side of the Y-shaped guide 3 is less than the height of the feed inlet 22. When guiding a single layer of ultra-thin metal foil, the Y-shaped guide 3 exits through the feed inlet 22 and exits outside the cavity 21. The Y-shaped guide 3 has two symmetrically arranged metal foil guiding surfaces, which, from front to back, include a large inclined guiding surface, a horizontal guiding surface, and a small inclined guiding surface, all inclined towards the center of symmetry. The total distance between the front ends of the two large inclined guiding surfaces is less than the height of the feed inlet 22. The rear ends of the two small inclined guiding surfaces are connected, and the connection point of the two small inclined guiding surfaces is near the pressing point of the flexible roller assembly 5, used to guide the physical joining of the two layers of ultra-thin metal foil. The front end of the Y-shaped guide 3 is located inside the feed inlet 22. Guide rails and locking devices are respectively arranged on both sides of the single- and double-layer compatible electrostatic coating chamber 2. The corresponding guide rails are slidably installed on both sides of the Y-shaped guide 3, and the locking devices are locked in place with the Y-shaped guide 3.

[0039] A movable cover plate 6 is provided on the upper and lower sides of the feed inlet 22. After the Y-shaped guide 3 exits the cavity 21, the two movable cover plates 6 move symmetrically toward the center position and close the feed inlet 22, forming a feed gap 25 between the upper and lower movable cover plates 6; the height of the discharge gap 23 and the feed gap 25 is less than 0.5cm.

[0040] Both sets of tension control rollers 1 are equipped with magnetic powder brakes and tension sensors; the magnetic powder brakes are equipped with servo motors, which receive signals from the tension sensors and drive the tension control rollers using PID closed-loop control. The difference in mechanical tension between the two sets of tension control rollers is less than 10 N / m.

[0041] The end of the atomizing nozzle 4 is electrically connected to a high-voltage electrostatic generator. The tension control roller group 1 and the Y-type guide 3 are grounded respectively, forming a high-voltage electrostatic field in opposite directions on the upper and lower sides of the ultra-thin metal foil. An ultrasonic transmission rod is installed at the end of the atomizing nozzle 4, and the ultrasonic transmission rod is connected to the ultrasonic generator.

[0042] The linkage operation relationship of the equipment in the double-layer copper foil lamination mode. Figure 1As shown, when producing double-layer laminated copper foil of extreme thickness, two tension control roller groups 1 are activated. The upper and lower copper foil layers are wound onto the two tension control roller groups 1 respectively. Under closed-loop control, they pass through the coating chamber at an angle in a "Y" shape with nearly uniform mechanical tension. Inside the closed chamber of cavity 21, the high-voltage electrostatic generator is activated, causing the cold rolling oil micro-mist sprayed from the atomizing nozzle 4 to carry a negative charge. Since the tension control roller group 1 is grounded, the two layers of copper foil are at a positive potential. Under the physical attraction of the electrostatic field, the oil mist particles are directionally and extremely uniformly adsorbed onto the outer surface (i.e., the matte surface) of the two layers of copper foil that are about to be bonded. Subsequently, the two layers of copper foil with electrostatic oil film enter the flexible guide pressing roller system composed of flexible roller group 5 at the discharge end. The flexible upper and lower pressure rollers use the elastic deformation of the polymer coating to physically bond the two layers of copper foil together, completely avoiding the mutual meshing of the micro-rough peaks on the metal surface. The double-layered copper foil then enters the cold rolling roll of the main rolling mill. The two layers of copper foil always maintain a smooth extension with an extremely low coefficient of friction, thus perfectly eliminating the periodic "double rib marks" on the surface caused by friction instability.

[0043] The interconnected operation relationship of the equipment in a single copper foil rolling mode. Figure 2 As shown, when producing single-layer copper foil that does not require stacking, no changes to the equipment's hardware structure are needed. Simply move the Y-shaped guide out of the single / double-layer compatible electrostatic coating chamber, change the vertical position of the two tension control roller groups 1 via the roller lifting mechanism to alter the feeding path, deactivate one set of unwinding modules, and allow the single copper foil to pass horizontally through the geometric center of the coating chamber via the unwinding module. At this time, the atomizing nozzle arrays 4 on the upper and lower sides inside the chamber 21 operate simultaneously. Relying on the unique "encircling effect" of the electrostatic field, the negatively charged oil mist overcomes the influence of gravity and adheres extremely evenly and firmly to the upper and lower surfaces of the grounded single-layer copper foil, achieving double-sided, dead-angle-free coverage that mechanical roller coating cannot achieve, completely eliminating oil dripping. Subsequently, the single-layer copper foil passes through the flexible guide pressing roller system. At this point, the flexible roller assembly no longer performs the "closing" function, but instead uses the physical pressing effect of the flexible roller assembly to play the role of "guiding and flattening", further flattening the electrostatic oil film on both sides and penetrating into the surface of the copper foil, ensuring that the single-layer copper foil will not cause dry friction and mechanical chatter due to local lack of oil when entering the main rolling mill.

[0044] The design of the single / double-layer path compatible structure, employing a combined geometric design of a "Y"-shaped guide cavity and a flexible pressing roller system, enables the device to achieve extremely high process compatibility with "one machine for two uses." The advantages are: companies do not need to purchase two separate coating equipment. Simply adjusting the material threading path allows for seamless and rapid switching between "double-layer overlay anti-rib mark mode" and "single copper foil high-precision lubrication mode." This solves the interlayer anti-interference lubrication problem in the overlay process and is backward compatible with double-sided precision coating of single-layer copper foil, significantly reducing equipment procurement costs and improving equipment utilization and scheduling flexibility of the rolling production line.

[0045] The electrostatic micro-mist coating chamber design innovatively introduces a high-voltage electrostatic field mechanism within a closed cavity. This allows negatively charged oil mist particles to actively overcome airflow disturbances and automatically seek out and tightly adhere to the grounded copper foil surface under the attraction of opposite charges. The advantage lies in achieving an absolutely uniform microscopic oil film coverage that is impossible with traditional mechanical coating. This extremely uniform oil film eliminates the physical "stickiness-slippage" of metal under high pressure from the root cause of mechanical tribology, completely eliminating the "double rib mark" defect that easily occurs in double-layer lamination.

[0046] The electrostatic envelopment effect and closed-structure design utilize the electrostatic properties of like charges repelling and unlike charges attracting to tightly envelop the copper foil with atomized oil droplets. The advantages are: it completely eliminates the scattering, dripping, and oil mist phenomena of rolling oil in traditional open-spray processing. This not only achieves zero waste of rolling oil and reduces consumable costs, but also significantly reduces the cleaning burden of subsequent products, greatly improving the environmental protection and production safety environment of the workshop.

Claims

1. A pretreatment device for electrostatic assisted coating compatible with single and double-layer ultra-thin metal foil rolling, characterized in that: It includes an unwinding module, a single / double layer compatible electrostatic coating chamber (2), and a flexible guide pressing roller; The unwinding module is located at the front end of the coating pretreatment device and is used to output ultra-thin metal foil with a thickness of ≤10μm. Two sets of tension control rollers (1) are arranged symmetrically at the rear of the unwinding module. The single and double layer compatible electrostatic coating chamber (2) is provided with a closed cavity (21). The front side of the cavity (21) is provided with a feed inlet (22), and the rear side of the cavity (21) is provided with a discharge slit (23). Multiple guide rollers (24) are installed inside the cavity (21), and the tension control roller group (1) is located in front of the feed inlet (22). A Y-shaped guide (3) is movably installed inside the cavity (21). The Y-shaped guide (3) extends from the feed inlet (22) to the middle and rear side of the cavity (21). A Y-shaped guide opening with a height that converges from the outside to the inside is provided on the front side of the cavity (21). Each guide roller (24) abuts against the upper and lower surfaces of the Y-shaped guide (3) respectively, forming a Y-shaped guide path on the outside of the Y-shaped guide (3) for guiding two layers of extremely thin metal foil. The maximum height on the left side of the Y-shaped guide (3) is less than the height of the feed inlet (22). When guiding a single-layer ultra-thin metal foil, the Y-shaped guide (3) exits through the feed inlet (22) to the outside of the cavity (21). Multiple atomizing nozzles (4) that spray oil mist toward the center are respectively arranged on the upper and lower sides of the cavity (21). A flexible roller assembly (5) is installed inside the cavity (21), and the flexible roller assembly (5) is adjacent to the discharge seam (23).

2. The electrostatic assisted coating pretreatment device for rolling single and double-layer ultra-thin metal foils according to claim 1, characterized in that: The Y-shaped guide (3) has two metal foil guide surfaces arranged symmetrically on top and bottom. The metal foil guide surfaces include a large inclined guide surface, a horizontal guide surface, and a small inclined guide surface that are inclined towards the center of symmetry, from front to back. The total distance between the front ends of the two large inclined guide surfaces is less than the height of the feed inlet (22). The rear ends of the two small inclined guide surfaces are connected. The connection point of the two small inclined guide surfaces is close to the pressing point of the flexible roller group (5) to guide the two extremely thin metal foils to physically close together.

3. The electrostatic assisted coating pretreatment device for rolling single and double-layer ultra-thin metal foils according to claim 2, characterized in that: The front end face of the Y-shaped guide (3) is located inside the feed inlet (22). The single and double layer compatible electrostatic coating chamber (2) is provided with guide rails and locking devices on both sides respectively. The Y-shaped guide (3) is slidably installed on both sides respectively, and the locking device is locked in place with the Y-shaped guide (3).

4. The electrostatic assisted coating pretreatment device for rolling single and double-layer ultra-thin metal foils according to claim 1, characterized in that: A movable cover plate (6) is provided on the upper and lower sides of the feed inlet (22). After the Y-shaped guide (3) exits the cavity (21), the two movable cover plates (6) move symmetrically toward the center position and close the feed inlet (22), forming a feed gap (25) between the upper and lower movable cover plates (6). The height of the discharge slot (23) and the feed slot (25) is less than 0.5 cm; A cold rolling roller (7) is provided on the rear side of the discharge slot (23), and the cold rolling roller (7) is located on the outside of the single and double layer compatible electrostatic coating chamber (2).

5. The electrostatic assisted coating pretreatment device for rolling single and double-layer ultra-thin metal foils according to claim 1, characterized in that: Both sets of tension control rollers (1) are equipped with magnetic powder brakes and tension sensors; the magnetic powder brakes are equipped with servo motors, which receive signals from the tension sensors and drive the tension control rollers using PID closed-loop control. The difference in mechanical tension between the two sets of tension control rollers is less than 10 N / m.

6. The electrostatic assisted coating pretreatment device for rolling single and double-layer ultra-thin metal foils according to claim 1, characterized in that: The unwinding module is equipped with two independently controlled roller lifting mechanisms, and the two tension control roller groups (1) are respectively installed in the corresponding roller lifting mechanisms.

7. A pretreatment apparatus for electrostatic assisted coating of single- or double-layer ultra-thin metal foil rolling according to any one of claims 1 to 6, characterized in that: The end of the atomizing nozzle (4) is electrically connected to a high-voltage electrostatic generator. The tension control roller group (1) and the Y-shaped guide (3) are grounded respectively, forming a high-voltage electrostatic field with opposite directions on the upper and lower sides of the ultra-thin metal foil. An ultrasonic transmission rod is installed at the end of the atomizing nozzle (4), and the ultrasonic transmission rod is connected to the ultrasonic generator.

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