Aluminum foil double sheet merging horizontal copper plating production line and production method

Abstract

This invention discloses a production line and method for horizontal copper plating of two aluminum foil sheets. The production line includes a dual-station unwinding unit, a flattening and bonding mechanism, an edge connecting mechanism, at least one plating bath device, a drying unit, a cutting mechanism, and a dual-station winding unit arranged sequentially. The plating bath device is equipped with alternating upper and lower pressure rollers, which apply alternating downward and upward forces to the aluminum foil to overcome buoyancy and maintain horizontal transport. The drying unit includes at least one cold air knife and at least one hot baking oven. The method includes seven steps: simultaneously unwinding two layers of aluminum foil, flattening and bonding, connecting along both edges, maintaining horizontal transport in the plating bath through alternating pressure, combined hot and cold drying, cutting and separating along the inner side of the connecting area, and separate winding. This invention integrates double-sheet merging, horizontal copper plating, gradient drying, and separate winding into a compact production line, doubling the single-line capacity while ensuring plating quality.

Description

Technical Field

[0001] This invention relates to the field of metal foil surface treatment equipment and process technology, specifically to a horizontal copper plating production line for merging two aluminum foil sheets and a method for horizontal copper plating of aluminum foil. Background Technology

[0002] Copper plating of aluminum foil is a crucial process in the production of functional composite materials such as copper-clad laminates and battery current collectors. Currently, the mainstream industrial production model for copper plating of aluminum foil is single-sheet unwinding and single-sheet processing, meaning that one unwinding machine releases one sheet of aluminum foil, which then passes through a plating bath, a drying device, and a rewinding machine to complete the copper plating process. This single-sheet processing model faces bottlenecks in terms of capacity expansion. Given that the chemical reaction rate in the plating bath is already approaching its limit, increasing the speed of a single production line will shorten the residence time of the aluminum foil in the plating bath, resulting in insufficient or uneven plating thickness. To increase speed without sacrificing quality, the only options are to extend the length of the plating tank or increase the number of tanks, but this would lead to a significant increase in the production line's footprint and a proportional increase in equipment investment. Another approach is to add a completely independent production line, but this also faces the problem of a substantial increase in footprint, energy consumption, and labor costs. Therefore, how to improve the copper plating capacity of a single production line within limited space and cost constraints has become a long-standing technical problem that the industry has been seeking to solve.

[0003] Besides production capacity issues, the transport stability of aluminum foil in a liquid environment is a core factor affecting coating quality. Aluminum foil is typically several micrometers to tens of micrometers thick, making it a flexible, extremely thin material. When it passes horizontally through a plating solution, the buoyancy of the liquid causes the aluminum foil to bulge upwards between two support points, creating a wave-like undulation that leads to uneven coating thickness. In practice, increasing the tension of the aluminum foil is usually used to suppress this undulation. However, the tension that extremely thin aluminum foil can withstand is very limited; excessive tension will cause plastic deformation or even breakage. This creates an irreconcilable contradiction—sufficient constraint is needed to counteract buoyancy and maintain flatness, while the mechanical tolerance limit of the aluminum foil itself cannot be exceeded.

[0004] Some technicians have proposed stacking multiple aluminum foils and performing surface treatment simultaneously to improve efficiency. However, this simple stacking method brings a series of new problems: during the journey, the two aluminum foils may slip and misalign due to tension differences and liquid intrusion. After processing, the two aluminum foils need to be separated, but the surfaces in the stacked state may adhere or stick together, which can easily cause scratches during separation. Existing guide roller conveying systems can only apply uniform, unidirectional constraint to aluminum foil, failing to effectively counteract buoyancy issues. These problems have prevented the development of an industrially viable technical solution for the long-standing concept of merging multiple sheets for horizontal copper plating.

[0005] In the drying process, the traditional single hot air drying method also has its shortcomings. Aluminum foil fresh from the plating bath has a large amount of liquid adhering to its surface. If it is directly placed into a high-temperature oven, the liquid evaporates rapidly at high temperatures, easily leaving solute spots on the aluminum foil surface. Simultaneously, the humid and hot environment may accelerate oxidation and discoloration of the plating surface, affecting the surface smoothness and color consistency of the final product. On the other hand, simply blowing with cold air is insufficient to completely remove residual moisture that has seeped into the micropores of the plating layer, potentially causing the aluminum foil to stick together after winding.

[0006] In summary, current technologies lack a compact production line and corresponding production method that can organically integrate parallel dual-sheet supply, reliable merging, stable horizontal transport in liquid, efficient gradient drying, non-destructive separation, and independent winding. This has made it difficult for the aluminum foil copper plating industry to achieve a balance between capacity, quality, and equipment compactness for a long time, necessitating a new production line layout and process method to systematically solve the above problems. Summary of the Invention

[0007] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a horizontal copper plating production line for merging two aluminum foil sheets, comprising: A dual-station unwinding unit is used to simultaneously unwind the upper and lower layers of aluminum foil; The flattening and bonding mechanism is located downstream of the dual-station unwinding unit and is used to flatten and tightly bond the two stacked aluminum foils. An edge connecting mechanism, located downstream of the flattening and bonding mechanism, is used to connect the two sides of the laminated aluminum foil, so that the two aluminum foils are formed into a combined aluminum foil that can be cut and separated. At least one plating bath device, disposed downstream of the edge connecting mechanism, is used to contain plating solution and allow the assembled aluminum foil to pass horizontally for surface copper plating. The plating bath device includes: The tank and the pressure roller assembly disposed within the tank, the pressure roller assembly including at least one upper pressure roller and at least one lower support roller, the upper pressure roller and the lower support roller being alternately arranged along the aluminum foil traveling direction to alternately apply downward and upward pressure forces to the combined aluminum foil; A drying unit, located downstream of the plating bath device, is used to dry the copper-plated composite aluminum foil. The drying unit includes at least one cold air knife and at least one hot baking oven. The cutting mechanism, located downstream of the drying unit, is used to cut along the inner side of the connecting area on both sides of the combined aluminum foil to remove the connecting area and separate the two aluminum foils. The dual-station winding unit is used to separately wind up the upper and lower aluminum foil layers after they have been separated by the cutting mechanism.

[0008] Its advantages are as follows: Through the integrated operation of seven functional units, a fully automated dual-plate parallel copper plating production line is constructed, from raw materials to finished products. Dual-station unwinding and rewinding, combined with edge joining and cutting separation, doubles the single-line capacity. Alternating pressure rollers in the plating bath utilize alternating force systems to counteract buoyancy, ensuring uniform plating. The drying unit employs a combined hot and cold drying method, balancing drying efficiency and surface quality. The entire line is compact, highly automated, and suitable for large-scale production.

[0009] The present invention provides a further solution, wherein the drying unit includes a first cold air knife, a first hot baking oven, a second hot baking oven, and a second cold air knife arranged sequentially along the aluminum foil traveling direction. Its advantages are: the gradient combination of cold air pre-blowing, two-stage hot baking, and cold air cooling can sequentially remove large droplets, achieve deep drying and cooling for shaping, prevent surface oxidation, and improve drying quality.

[0010] The present invention provides a further solution, wherein the plating bath device further includes: an inlet sealing plate and an outlet sealing plate, spaced apart within the bath to define a plating bath containing space between them; a set of pressure rollers located within the plating bath containing space; a pair of feed squeezing rollers, positioned upstream of the inlet sealing plate, for squeezing out surface liquid from the assembled aluminum foil before it enters the plating bath containing space; a pair of discharge squeezing rollers, positioned downstream of the outlet sealing plate; and a pair of cold air knives, positioned downstream of the discharge squeezing rollers, for airflow purging of the upper and lower surfaces of the assembled aluminum foil. Its advantages are: the sealing plates partition and limit the plating bath, reducing leakage; the feed squeezing blocks preceding liquids, preventing cross-contamination; and the discharge squeezing combined with the air knives efficiently removes liquid, protecting the plating layer.

[0011] The present invention provides a further solution in which multiple plating bath devices are arranged in series. Its advantages are: multiple copper plating operations allow for flexible adjustment of the total plating thickness and interlayer structure; modular series expansion is convenient and adaptable to different process requirements.

[0012] The present invention provides a further solution, wherein the edge connection mechanism is an ultrasonic welding mechanism. Its advantages are: the welding is clean and pollution-free, the weld is corrosion-resistant and reliable, and the waste edge area can be completely removed by subsequent cutting, achieving true non-destructive separation.

[0013] The present invention provides a further solution, wherein the cutting mechanism includes a circular roller cutter, and a pressure roller is correspondingly arranged above the circular roller cutter. The pressure roller presses the aluminum foil onto the circular roller cutter to achieve cutting. The positions of the circular roller cutter and the pressure roller in the width direction of the aluminum foil can be adjusted independently. Its advantages are: the circular roller cutter, in conjunction with the pressure roller, achieves rolling cutting, resulting in a smooth cut; the position is adjustable to adapt to different widths, improving the versatility of the production line and cutting accuracy.

[0014] The present invention provides a further solution, wherein the cold air knife is a narrow slit-type air outlet with upper and lower opposing structures, and the hot air drying oven is a hot air circulating oven. Its advantages are: the narrow slit air knife forms a uniform air curtain for efficient blowing; the hot air circulating oven has uniform temperature and efficient heat transfer, jointly ensuring drying quality.

[0015] This invention provides a method for producing aluminum foil with horizontal copper plating. include: Step S1: Release the upper aluminum foil and the lower aluminum foil at the same time, so that they are stacked on top of each other; Step S2: Flatten and tightly adhere the two stacked aluminum foils to form a stacked aluminum foil; Step S3: Connect the two sides of the stacked aluminum foil to form a combined aluminum foil that can be cut and separated; Step S4: The combined aluminum foil is subjected to surface copper plating by passing it through at least one plating bath device. During the passage through the plating bath, the combined aluminum foil is kept horizontally transported in the plating bath by alternately applying downward and upward holding forces. Step S5: Dry the copper-plated aluminum foil, including at least one cold air purging and at least one hot baking; Step S6: Cut along the inside of the connecting area on both sides of the dried combined aluminum foil to remove the connecting area and separate the two aluminum foils; Step S7: Rewind the separated upper and lower aluminum foils separately.

[0016] Its advantages are as follows: Through seven sequentially linked process steps, parallel copper plating of two aluminum foils can be completed on the same production line. Step S3 adopts a reversible connection design, reserving conditions for non-destructive separation. Step S4 overcomes buoyancy by using alternating directional holding forces to ensure uniform plating. Step S5 uses a combination of hot and cold drying to protect the plating surface. This method is independent of specific equipment, has a wide protection range, and can cover non-production line sales scenarios such as OEM services.

[0017] The present invention provides a further solution in which, in step S5, the drying is performed in the following order: first, cold air purging; then, at least one hot drying cycle; and finally, cold air purging. Its advantages are: the method steps clearly define the gradient drying sequence, constructing a process feature distinct from conventional single-drying methods, and providing a ground for inventive step in the protection of the method claims.

[0018] The present invention provides a further solution: in step S4, the alternating downward and upward holding forces applied to the combined aluminum foil are achieved by alternating upper pressure rollers and lower support rollers arranged along the aluminum foil's travel direction within the plating solution containing space. Adjacent upper pressure rollers and lower support rollers overlap in the vertical direction, causing the combined aluminum foil to bend in an S-shape as it passes through. Its advantages are: functional features are reduced to specific structural and mechanical mechanisms; the S-shaped bending generated by the overlap can construct a constraint force system with alternating directions, fundamentally counteracting buoyancy and providing a strong inventive step argument for the method claims.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By combining dual-station unwinding, edge joining, cutting and separation, and dual-station rewinding, two aluminum foils are reversibly joined into a whole for parallel processing. After processing, they are separated without damage, which doubles the output per unit time of a single production line. At the same time, compared with adding a completely independent production line, it can significantly save equipment investment and floor space.

[0020] 2. The alternating upper pressure rollers and lower support rollers in the plating bath device form a holding force system with opposite directions and staggered spatial arrangement, which can effectively counteract the buoyancy effect of the plating solution on the thin aluminum foil and forcibly constrain the aluminum foil on a quasi-horizontal travel path. This fundamentally solves the technical problems of unstable transmission of aluminum foil and uneven coating thickness in the liquid environment from a mechanical perspective.

[0021] 3. The drying unit adopts a gradient combination of cold air pre-blowing, two-stage hot drying, and cold air cooling to remove large volume of free liquid, completely evaporate residual moisture, and cool and shape in sequence. This effectively avoids surface oxidation and discoloration and solute spots that may be caused by single hot drying, and improves the surface smoothness and color consistency of the finished product.

[0022] 4. The plating bath device limits the plating bath capacity by sealing the plate. Combined with the feeding squeezing roller and the multi-stage liquid removal system, it reduces plating bath leakage and loss and avoids cross-contamination between tanks. Individual plating baths can be flexibly added or removed as functional modules, which greatly improves the process adaptability and expansion convenience of the production line.

[0023] 5. The production line integrates the dual placement, merging, copper plating, drying, separation, and dual collection units in a compact and integrated manner, automating the entire process from raw materials to finished products. This reduces offline transfer links, making it suitable for large-scale industrial applications. Furthermore, the method claims can cover non-equipment sales scenarios such as OEM services, ensuring a complete protection chain. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a structural diagram of a horizontal copper plating production line for merging two aluminum foil sheets according to an embodiment of the present invention.

[0026] Figure 2 This is a structural diagram of a flattening and bonding mechanism, an edge connecting mechanism, and a plating bath device according to an embodiment of the present invention.

[0027] Figure 3 This is a structural diagram of a cutting mechanism according to an embodiment of the present invention.

[0028] Figure 4 This is a structural diagram of the flattening and bonding mechanism and the edge connecting mechanism according to an embodiment of the present invention.

[0029] Figure 5 This is a structural diagram of a plating bath device according to an embodiment of the present invention.

[0030] Figure 6 This is a structural diagram of a drying unit according to an embodiment of the present invention.

[0031] Figure 7 for Figure 1 A magnified view of region A in the middle.

[0032] The correspondence between the numbers and component names in the diagram is as follows: 1. Flattening and bonding mechanism; 2. Edge connecting mechanism; 21. Ultrasonic welding mechanism; 211. Ultrasonic welding head; 3. Plating tank device; 31. Tank body; 32. Inlet sealing plate; 33. Outlet sealing plate; 34. Feeding squeezing roller pair; 35. Discharge squeezing roller pair; 36. Cold air knife pair; 37. Final squeezing roller pair; 38. Holding roller group; 381. Upper pressure roller; 382. Lower support roller; 4. Cutting mechanism; 41. Circular roller cutter; 42. Pressure roller; 5. Double-station unwinding unit; 6. Double-station winding unit; 7. Drying unit; 71. First cold air knife; 72. First hot baking oven; 73. Second hot baking oven; 74. Second cold air knife. Detailed Implementation

[0033] The invention will now be described in further detail with reference to its specific structure.

[0034] The aluminum foil double-sheet horizontal copper plating production line of the present invention consists of seven functional units connected in series along the aluminum foil travel direction: a dual-station unwinding unit 5, a flattening and bonding mechanism 1, an edge connecting mechanism 2, a copper plating tank group composed of several plating bath devices 3 connected in series, a drying unit 7, a cutting mechanism 4, and a dual-station winding unit 6. From the loading of the aluminum foil raw material to the unloading of the copper-plated finished product, the aluminum foil strip continuously travels between the units, eliminating offline transfer links and realizing fully automated continuous operation. Its core inventive concept lies in creatively realizing a parallel processing paradigm of merging two extremely thin aluminum foils into one and separating them into two. Merging refers to safely and reliably connecting the two aluminum foils in the waste edge area to form a coordinating whole; separating refers to precisely cutting off the waste edge from the inside of the connection position after completing all copper plating processes, so that the finished aluminum foil is intact and undamaged. Throughout the assembly and disassembly process, a unique set of staggered pressure rollers overcomes buoyancy in the liquid environment of the plating bath, ensuring that the assembled aluminum foil can be copper-plated stably like a single thick plate. The drying unit employs a gradient combination of cold air pre-blowing, two-stage hot drying, and cold air cooling, thoroughly drying the foil while avoiding oxidation and spot defects caused by direct high-temperature baking of the damp aluminum foil. The production method solidifies these steps in a sequential manner, allowing the method to be implemented independently of specific equipment. This organic unity of the three forms the cornerstone of this invention.

[0035] Working Principle Overview: The two unwinding machines in the dual-station unwinding unit 5 release the upper and lower aluminum foil layers under constant tension control. Guided by the guide rollers, the two foils enter the flattening and bonding mechanism 1 in a stacked state. The flattening and bonding mechanism 1 operates based on the expulsion of interlayer air and uniform pressing. When the two aluminum foils enter, there is a natural gap. When the gap is adjusted to be less than or equal to the sum of the thicknesses of the two foils by the opposing flattening rollers, the linear pressure applied to the roller surface squeezes out the residual air along the width direction, achieving a tight surface-to-surface bonding of the two aluminum foil layers. The laminated aluminum foil maintains a stable stacked state without relative slippage under the combined action of surface adhesion and pressing stress. The edge connecting mechanism 2 works by physically merging the two aluminum foils into a single unit and setting the connection point in the process waste area where the final product is unusable, ensuring subsequent non-destructive separation. The pressure roller group 38 within the plating bath device 3 is the core component ensuring horizontal transport. Its working principle is based on a buoyancy cancellation mechanism of alternating directional forces: the upper pressure roller 381 and the lower support roller 382 are alternately configured. The overlap of adjacent rollers in the vertical direction forces the aluminum foil to undergo a slight S-shaped bend. When the buoyancy of the plating bath attempts to lift the aluminum foil upwards, the downward pressure force immediately cancels it out. Conversely, the upward support force prevents it from sinking, thus constraining the travel path of the aluminum foil within the entire plating bath containment space to a quasi-horizontal envelope defined by the alternating force system. The lower support roller 382, ​​not explicitly shown in the figure, is located below the midpoint of the line connecting the two upper pressure rollers 381 and lifts the stacked aluminum foil from below. The working principle of the drying unit 7 is based on the gradient drying concept. First, the high-speed dynamic pressure of the cold air flow breaks up and blows away the large volume of free liquid on the surface of the aluminum foil. Then, the residual moisture that has penetrated into the micropores of the coating is completely evaporated in a uniform temperature field through hot air circulation baking. Finally, the surface temperature of the aluminum foil is lowered to near room temperature again by cold air, while removing the trace amounts of floating dust that may re-adhere during the drying process, and avoiding thermal stress deformation that may occur when the aluminum foil comes into contact with the cold roller surface of subsequent equipment at a high temperature. The working principle of the cutting mechanism 4 is to achieve rolling cutting by cooperating with the circular roller cutter 41 and the pressure roller 42. The circular roller cutter 41 is located below the aluminum foil to provide a cutting edge, and the pressure roller 42 presses the aluminum foil onto the surface of the circular roller cutter 41 from above. The combined aluminum foil is continuously cut as it passes through.

[0036] Work Process Description: During operation, the two unwinding machines of the dual-station unwinding unit 5 each release the upper and lower aluminum foils at preset tensions. Guided by guide rollers, the two aluminum foils enter the flattening and bonding mechanism 1 in a stacked state. After being flattened and bonded, they form stacked aluminum foils and are fed into the edge connecting mechanism 2. The edge connecting mechanism 2 performs a connecting operation along both edges of the stacked aluminum foils, outputting combined aluminum foils. The combined aluminum foils then sequentially enter each plating bath device 3. In a single plating bath device 3, the combined aluminum foils first pass through the feed squeezing roller pair 34, which works in conjunction with the inlet sealing plate 32. Before the combined aluminum foils enter the plating bath containing space, the preceding liquid adhering to their surface is squeezed off and recovered, establishing a normal-pressure feed transition zone, thus eliminating the risk of contamination of the plating bath by liquids from previous stations. Then, passing through the slit on the inlet sealing plate 32, the aluminum foil enters the plating solution containing space. Under the alternating pressure of the holding roller group 38, the composite aluminum foil is endowed with posture stability far exceeding its own stiffness, allowing it to pass through the plating solution in a horizontal posture to complete copper plating. Afterward, it passes through the slit on the outlet sealing plate 33 to leave the plating solution containing space and enters a multi-stage descaling process. Each stage of the discharge system works in concert, each performing its specific function: the discharge squeezing roller 35 reduces the volume of liquid, squeezing large volumes back into the tank; the cold air knife 36 breaks the film, using aerodynamic effects to tear the liquid film; and the final squeezing roller 37 clears the liquid, acting as the last physical barrier to scrape away residual droplets. This forms a progressively increasing drying gradient, ensuring that any small amount of residue at any stage is captured by the next stage, guaranteeing absolute reliability of the discharge. After flowing through several plating tank devices 3 to complete the required multiple copper plating processes, the composite aluminum foil enters the drying unit 7. In the drying unit 7, the combined aluminum foil is sequentially pre-blown by the first cold air knife 71, initially dried by the first hot baking oven 72, second dried by the second hot baking oven 73, and cooled and finally blown by the second cold air knife 74. After drying, the combined aluminum foil enters the cutting mechanism 4, where the circular roller cutter 41 and the pressure roller 42 continuously cut along the inner side of the left and right connecting areas, respectively. The outer waste edge is collected by the waste edge rewinder, and the middle part is separated into upper aluminum foil and lower aluminum foil, which are guided to the two rewinders of the dual-station rewinding unit 6 for rewinding.

[0037] In the production line, the core actuating component of the flattening and bonding mechanism 1 is at least a pair of vertically opposed flattening rollers. The upper and lower aluminum foil layers pass between these rollers. The gap between the rollers is adjusted to be less than or equal to the sum of the thicknesses of the two aluminum foils. During passage, the rollers apply uniform linear pressure to the aluminum foil, squeezing out any residual air between the two layers along the width direction, achieving a tight surface-to-surface bond. The bonded stacked aluminum foil maintains a stable state without relative slippage, eliminating the need for additional adhesive media. In some specific implementations, the surface of the flattening rollers is covered with an elastic material layer, such as an acid- and alkali-resistant rubber elastic layer or a polyurethane elastic layer. The presence of this elastic layer allows the flattening rollers to produce a small amount of elastic deformation when pressure is applied, converting the concentrated load into a distributed load with a certain width range, reducing localized pressure on the aluminum foil surface. In other implementations, pressure cylinders are installed at both ends of the upper flattening roller, allowing adjustment of the downward stroke and pressing force to accommodate aluminum foils of different thickness combinations.

[0038] The edge-connecting mechanism 2 serves to physically merge two aluminum foils into a single unit. The connection is chosen along both edges because these edges are unusable process waste areas in the final product. Regardless of the traces left by the connection operation at the edges, the integrity of the effective central area and the performance of the final product will not be affected. Setting the connection location in the waste area is a key spatial layout strategy for achieving temporary connection and final separation. As a preferred connection method, the edge-connecting mechanism 2 can be specifically implemented as an ultrasonic welding mechanism 21. Ultrasonic welding utilizes high-frequency mechanical vibration energy, transmitted through the welding head to the interface of the two aluminum foil layers. The high-frequency friction and stress concentration at the interface break down the oxide layer on the aluminum foil surface, exposing a fresh metal surface that forms a solid metallurgical bond under pressure. No filler metal, flux, or adhesive is required during the welding process, and no chemical contaminants are introduced to the aluminum foil surface. The weld area itself is also corrosion-resistant enough to withstand the acidic and alkaline environment of the subsequent plating bath. In terms of specific structure, the ultrasonic welding mechanism 21 has a welding unit set on each of the left and right sides along the width direction of the aluminum foil. Each welding unit includes an ultrasonic welding head 211 and a supporting anvil located below the aluminum foil. The welding head 211 is located above, applying pressure and high-frequency vibration to the upper surface of the aluminum foil from top to bottom, while the anvil provides reaction support below. In some implementations, the welding head 211 is in the form of a welding roller, which continuously rolls along the direction of aluminum foil travel during welding, resulting in a continuous linear weld bead. In other implementations, the welding head 211 uses a planar welding head for pulsed spot welding, resulting in a weld bead composed of a series of evenly spaced weld spots. Both methods can be selected based on the actual aluminum foil thickness and production line speed.

[0039] The plating bath device 3 is the core functional unit that ensures the uniformity of the plating layer. The structure of a single plating bath device 3, arranged sequentially according to the aluminum foil's travel direction, includes an inlet squeezing roller pair 34, an inlet sealing plate 32, a pressure holding roller group 38, an outlet sealing plate 33, an outlet squeezing roller pair 35, and a cold air knife pair 36. The inlet squeezing roller pair 34 consists of two opposing, elastic squeezing rollers installed directly in front of the inlet sealing plate 32. The gap between the squeezing rollers is set to be less than the thickness of the combined aluminum foil. When the combined aluminum foil passes through, the roller surface adheres to the aluminum foil surface with a certain pressure, squeezing out most of the attached liquid and allowing it to flow back to the previous tank or collection tray along the roller surface. A deeper function of the squeezing rollers is to prevent liquid from the previous process or the previous plating bath from being carried into the plating bath's containing space by the aluminum foil, thereby avoiding mixing and contamination of plating solutions with different formulations or concentrations. The inlet sealing plate 32 and the outlet sealing plate 33 divide the internal space of the tank 31 into three parts: the inlet transition zone, the plating solution containing space, and the outlet transition zone. The sealing plates 32 and 33 are vertically installed plate-shaped components with transverse slits only at the positions where the aluminum foil passes through. The aluminum foil passes through the slits into the plating solution containing space. The pressure roller group 38 is located in the plating solution containing space. Its basic structure consists of two functional rollers, the upper pressure roller 381 and the lower support roller 382, ​​arranged alternately along the aluminum foil traveling direction. Adjacent upper pressure rollers 381 and lower support rollers 382 overlap in the vertical direction, forcing the aluminum foil to undergo a slight S-shaped bending deformation when passing through the two adjacent rollers. When the uniform buoyancy generated by the plating solution attempts to lift the aluminum foil upwards, the foil is immediately suppressed by the downward pressing force of the next upper pressure roller 381 just as it is about to move upwards within each free zone. Immediately after passing the upper pressure roller 381, the following lower support roller 382 provides upward support from below, preventing the aluminum foil from sinking excessively due to tension and gravity. It is through this multi-roller alternation, pressure-support constraint topology that the extremely thin composite aluminum foil is endowed with an artificial stiffness far exceeding the material's own rigidity in the liquid environment, achieving a stable posture similar to a rigid body. Thus, the aluminum foil's path within the entire plating solution is constrained within a quasi-horizontal envelope defined by alternating forces in opposite directions. Buoyancy cannot accumulate at any position to generate effective displacement, thereby fundamentally guaranteeing the uniformity of the coating thickness at the mechanical level. When the process requires multiple copper plating operations, multiple plating bath devices 3 with the same structure can be connected in series along the direction of aluminum foil travel. Each bath 31 is an independent functional module with its own sealing structure, pressure roller group 38 and liquid removal system. They are connected to each other only through the aluminum foil strip itself. Adding or removing a bath only involves mechanical disassembly and assembly and aluminum foil threading operations, without affecting the integrity of the production line and the normal operation of other modules.

[0040] Drying unit 7 is a key unit for ensuring the surface quality of the finished product. Drying unit 7 is arranged sequentially according to the aluminum foil's travel direction: first cold air knife 71, first hot baking oven 72, second hot baking oven 73, and second cold air knife 74. The cold air knives 71 and 74 are vertically opposed slit-type air outlets. Compressed air is delivered to the knives through pipes and forms a high-speed, sheet-like airflow through the narrow gaps, blowing at a certain angle onto the upper and lower surfaces of the aluminum foil. When the high-speed airflow impacts the liquid film, the dynamic pressure of the airflow overcomes the surface tension of the liquid, tearing and atomizing the liquid film and blowing it away from the aluminum foil surface in the form of tiny droplets. The cold air knives use ambient temperature air, without heating, avoiding the oxidation and discoloration problems that may occur if heat is introduced onto the aluminum foil surface. The hot baking ovens 72 and 73 are hot air circulating ovens. Heated air is evenly sprayed onto the upper and lower surfaces of the aluminum foil through pipes and nozzles and then recycled. The temperature field distribution inside the oven is uniform, the heat transfer efficiency is high, and the evaporated water vapor can be quickly removed. The first and second hot baking ovens 72 and 73 can be set to the same or different target temperatures. In practical applications, the temperature profiles can be flexibly adjusted according to the coating thickness and production line speed. The design logic of the gradient drying sequence is that the aluminum foil surface, fresh from the plating bath, carries a large amount of free liquid water. If it enters the high-temperature oven directly, the rapid boiling and evaporation of this water may cause tiny pores or cracks on the coating surface, and the humid and hot environment accelerates the oxidation and discoloration of the copper plating layer. The pre-blowing of the first cold air knife 71 can mechanically remove most of the large volume and flow of free liquid, leaving only a uniform thin layer of moisture. This ensures that the aluminum foil surface is already in a relatively uniform wet state rather than a state of being flooded with water when it enters the first hot baking oven 72. The two-stage hot baking setting allows the temperature of each stage to gradually and thoroughly evaporate the moisture without being too high, while reducing the potential impact of a single-stage high temperature on the mechanical properties of the aluminum foil. The second cold air knife 74 ultimately lowers the temperature of the aluminum foil to near room temperature and blows away any residual dust, ensuring that the aluminum foil is clean and at a suitable temperature when it enters the cutting and winding process, thus avoiding uneven thermal stress shrinkage when the high-temperature aluminum foil comes into contact with the cold roller of the winding machine.

[0041] The cutting mechanism 4 is located downstream of the drying unit 7, with a cutting unit on each side of the aluminum foil width direction. Each cutting unit includes a rotary cutter 41 and a pressure roller 42. The rotary cutter 41 is located below the aluminum foil, serving as a rolling shearing blade; the pressure roller 42 is positioned above the rotary cutter 41, pressing the aluminum foil against its surface. The aluminum foil is continuously cut as it passes between the rotary cutter 41 and the pressure roller 42. The two cutting units are aligned with the connecting areas on the left and right sides of the combined aluminum foil, respectively, with the cutting position precisely set at the inner edge of the connecting area, i.e., the cut is located between the weld seam and the effective width. After cutting, the outer waste edge is continuously drawn out and collected, while the middle portion naturally separates into two independent strips: an upper aluminum foil and a lower aluminum foil. The lateral positions of the two sets of circular roller cutters 41 and pressure rollers 42 can be adjusted independently. The adjustment method can be manual screw adjustment or online automatic adjustment through servo motor to adapt to aluminum foil of different widths and different welding positions.

[0042] The dual-station winding unit 6 includes a first winding machine and a second winding machine. The winding machine is equipped with a constant tension control device and a correction device, which can independently wind the upper and lower aluminum foils with appropriate tension to ensure that the roll end face is neat and the winding density is uniform, which facilitates the subsequent storage and use of the finished product.

[0043] Assembly: The assembly of the entire production line follows the principle of modular pre-assembly and horizontal connection. In the modular pre-assembly stage, each functional unit is assembled and debugged separately. The dual-station unwinding unit 5 and the dual-station winding unit 6 are fixed on the foundation and leveled. The plating bath device 3 is assembled as a closed functional black box, and the key is to proceed from the inside out: First, the core skeleton inlet sealing plate 32 and outlet sealing plate 33, which determine the size of the plating bath capacity, are fixed in the predetermined positions on the inner side wall of the tank body 31; then, the functional heart pressure roller group 38 is implanted in the skeleton, and each upper pressure roller 381 and lower support roller 382 is installed into the bearing seat mounting holes on the side wall of the tank body 31 one by one according to the set alternating sequence and spacing; finally, the interface with the outside is installed, and the feed squeezing roller pair 34, the discharge squeezing roller pair 35 and the cold air knife pair 36 are installed in sequence at the inlet and outlet ends of the tank body 31, and each roller group and air knife is connected to the tank body 31 through an adjustable bracket. The various sections of the drying unit 7, including the housings and air knives, are connected in the designed sequence, with sealing and heat-insulating pads installed at the joints to reduce heat loss and airflow interference. During the production line connection phase, each functional module is treated as an independent unit and connected in series. The connection benchmark is to ensure the absolute horizontality and centering of the aluminum foil's traveling plane. Following the process flow sequence, the flattening and bonding mechanism 1, the edge connecting mechanism 2, several plating bath devices 3, the drying unit 7, and the cutting mechanism 4 are sequentially hoisted into place. By adjusting the height of the adjustable feet or transition rollers under each unit, the entire processing section from the flattening and bonding mechanism 1 to the cutting mechanism 4 is made coplanar, thereby eliminating the additional stress on the aluminum foil caused by the slight height difference between modules. Finally, a tape threading test is conducted to confirm the tension matching and speed synchronization of each unit, completing the trial operation of the entire line.

[0044] The above specific embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection. Those skilled in the art can make equivalent substitutions or appropriate adjustments to the specific structure, materials, driving methods, and parameters of each mechanism without departing from the concept of the present invention. All such substitutions and adjustments should fall within the scope of protection of the present invention.

Claims

1. A horizontal copper plating production line for merging two aluminum foil sheets, comprising a dual-station unwinding unit (5), a flattening and bonding mechanism (1), an edge connecting mechanism (2), at least one plating bath device (3), a drying unit (7), a cutting mechanism (4), and a dual-station winding unit (6) arranged sequentially along the aluminum foil traveling direction. Its features are, The dual-station unwinding unit (5) is used to simultaneously unwind the upper aluminum foil and the lower aluminum foil; The flattening and bonding mechanism (1) is used to flatten and tightly bond the two aluminum foils stacked on top of each other; The edge connecting mechanism (2) is used to connect the two sides of the stacked aluminum foil, so that the two aluminum foils are formed into a combined aluminum foil that can be cut and separated. The plating bath device (3) is used to contain the plating solution and allow the combined aluminum foil to pass horizontally for surface copper plating. The plating bath device (3) includes a tank body (31) and a pressure roller group (38) disposed in the tank body (31). The pressure roller group (38) includes at least one upper pressure roller (381) and at least one lower support roller (382). The upper pressure roller (381) and the lower support roller (382) are alternately arranged along the aluminum foil traveling direction to alternately apply downward and upward pressure to the combined aluminum foil. The drying unit (7) is used to dry the copper-plated composite aluminum foil, and the drying unit (7) includes at least one cold air knife and at least one hot baking oven; The cutting mechanism (4) is used to cut along the inner side of the connecting area on both sides of the combined aluminum foil to remove the connecting area and separate the two aluminum foils; The dual-station winding unit (6) is used to wind up the upper and lower aluminum foils separated by the cutting mechanism (4) respectively.

2. The aluminum foil double-web merge horizontal copper plating production line according to claim 1, characterized in that, The drying unit (7) includes a first cold air knife (71), a first hot baking oven (72), a second hot baking oven (73), and a second cold air knife (74) arranged sequentially along the aluminum foil traveling direction.

3. The aluminum foil double-web merge horizontal copper plating production line according to claim 1, characterized in that, The plating bath device (3) further includes: an inlet sealing plate (32) and an outlet sealing plate (33), which are spaced apart in the tank body (31) to define a plating bath containing space between them; the pressure roller group (38) is located in the plating bath containing space; a feeding squeezing roller pair (34), which is located upstream of the inlet sealing plate (32) and is used to squeeze out the liquid on the surface of the combined aluminum foil before it enters the plating bath containing space; a discharging squeezing roller pair (35), which is located downstream of the outlet sealing plate (33); and a cold air knife pair (36), which is located downstream of the discharging squeezing roller pair (35) and is used to blow air onto the upper and lower surfaces of the combined aluminum foil.

4. The aluminum foil double-web merge horizontal copper plating production line according to claim 1, characterized in that, The number of plating tank devices (3) is multiple, and they are connected in series.

5. The aluminum foil double-web merge horizontal copper plating production line according to claim 1, characterized in that, The edge connection mechanism (2) is an ultrasonic welding mechanism (21).

6. The aluminum foil double-web merge horizontal copper plating line of claim 1, wherein, The cutting mechanism (4) includes a circular roller cutter (41), and a pressure roller (42) is provided above the circular roller cutter (41). The pressure roller (42) presses the aluminum foil onto the circular roller cutter (41) to achieve cutting. The positions of the circular roller cutter (41) and the pressure roller (42) in the width direction of the aluminum foil can be adjusted independently.

7. The aluminum foil double-web merge horizontal copper plating line of claim 1, wherein, The cold air blade is a narrow slit-type air outlet with the upper and lower sides facing each other, and the hot baking oven is a hot air circulating oven.

8. A method for horizontal copper plating of aluminum foil, characterized in that include: Step S1: Release the upper aluminum foil and the lower aluminum foil at the same time, so that they are stacked on top of each other; Step S2: Flatten and tightly adhere the two stacked aluminum foils to form a stacked aluminum foil; Step S3: Connect the two sides of the stacked aluminum foil to form a combined aluminum foil that can be cut and separated; Step S4: The combined aluminum foil is subjected to surface copper plating through at least one plating bath device. During the passage through the plating bath, the combined aluminum foil is kept horizontally transported in the plating bath by alternately applying downward and upward holding forces. Step S5: Dry the copper-plated aluminum foil, the drying process including at least one cold air purging and at least one hot baking; Step S6: Cut along the inside of the connecting area on both sides of the dried combined aluminum foil to remove the connecting area and separate the two aluminum foils; Step S7: Rewind the separated upper and lower aluminum foils separately.

9. The aluminum foil horizontal copper plating production method according to claim 8, characterized by, In step S5, the drying is carried out in the following order: first, cold air blowing; then, at least one hot drying; and finally, cold air blowing.

10. The method for producing horizontal copper plating on aluminum foil according to claim 8, characterized in that, In step S4, the alternating downward and upward holding forces applied to the combined aluminum foil are achieved by alternating upper pressure rollers and lower support rollers arranged in the plating solution containing space along the aluminum foil traveling direction. Adjacent upper pressure rollers and lower support rollers overlap in the vertical direction, causing the combined aluminum foil to bend in an S-shape when passing through.

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