System for treating a metal foil

Abstract

The present invention relates to a system for treating a metal foil, wherein the system comprises a first roller, a second roller, and a treatment zone arranged therebetween, wherein the treatment zone has a planar surface over which the metal foil is guided during treatment, wherein the system is configured such that a magnetic field can be generated in the treatment zone during treatment.

Description

[0001] Singulus Technologies AG

[0002] 1

[0003] Vossius Ref.: AJ4099 PCT S5

[0004] Plant for treating a metal foil

[0005] The present invention relates in particular to a system for treating a

[0006] 5. Metal foil, preferably for coating and / or printing a metal foil, preferably for the production of printed electronics. In particular, the invention relates to a system and / or a section of a system for surface treatment, in particular wet chemical surface treatment, of a metal foil, preferably in a roll-to-roll process.

[0007] The prior art includes systems or system modules (i.e., sub-areas of a system) that can be used for surface treatment, for example, coating, and / or printing on a film, particularly metal film. Such systems have in common that they have a treatment area in which the metal film to be treated is processed through the system as flat as possible, so that, for example, uniform wetting can be achieved during wet chemical treatment. Many such systems are based on a so-called roll-to-roll process (abbreviated R2R from the English "roll-to-roll"). In this process, or in such system designs, the starting material is initially on a roll. The starting material is unwound, processed, and, if necessary, transported on or over rollers through the system and / or different system modules, and then rewound.The starting material is preferably a thin film, in particular a metal film, which extends significantly further in the longitudinal direction than in the width direction and is therefore rolled up lengthwise. In a roll-to-roll system, a multitude of rollers or cylinders, also called web guides, are typically provided, over and between which the starting material, e.g., the metal film, runs, while a series of operations can be carried out in one or more system modules.

[0008] In such roll-to-roll systems, problems regularly arise because the starting material, especially a thin film, tends to curl as it unwinds, making it difficult to achieve a flat surface for surface treatment, for example, within a 30 mm processing area. Therefore, it is generally necessary to flatten the film in the processing areas of roll-to-roll systems to ensure uniform wetting during surface treatment and / or to enable precise printing. Several methods are known for flattening a film within a processing area. For example, overhead rollers can be used to smooth the surface of the starting material, preferably the film.In this method, rollers are positioned in the processing area that press down on the film from above, for example, on its edges, as the film is processed. This smooths the film in this area, for example, by pressing the film onto a flat surface below using the rollers. However, this method cannot be used if the film's surface is so sensitive to touch that it cannot withstand mechanical contact from the rollers without being damaged. It is also known to tension the film in the processing area to stretch and thus smooth it through a tensile effect.However, such tensioning of the film is not possible or only possible to a limited extent in many applications, since films, especially thin films, can often only withstand low tensile forces and therefore cannot be stretched so tightly, at least in part, that the film can be smoothed due to the tension or the tensile forces acting upon it without damaging the film.

[0009] Another possibility is to utilize the Bernoulli effect and ensure a corresponding airflow beneath the foil, directing the airflow in such a way as to smooth the metal foil. Such airflows are typically created using targeted supply and exhaust air streams. Smoothing the foil with an airflow avoids direct mechanical stress on the foil's surface. However, in processing areas, particularly those for wet chemical surface treatments, substances are frequently used in the treatment processes that must not be released into the environment unfiltered. For example, solvents are typically used, which must be filtered out of the exhaust air using cumbersome separation devices to prevent environmental pollution.Therefore, smoothing methods based on the Bernoulli effect are extremely complex to implement and thus also costly and maintenance-intensive.

[0010] Known methods for guiding a metal foil flat through a processing area from one roll to the next in a roll-to-roll process all have disadvantages, particularly with regard to sensitive and / or thin metal foils. There is no method for guiding a metal foil flat through a processing area without subjecting the foil to significant mechanical stress, touching its surface, and / or requiring complex supply, exhaust, and filter systems.

[0011] There is a need for a system for treating a metal foil, in particular in a roll-to-roll process, wherein the metal foil can be guided flat through a processing or treatment area, and wherein the system is suitable for processing metal foils with highly sensitive surfaces, low tensile strengths and / or extremely thin dimensions, preferably with minimal effort.

[0012] It is therefore an object of the present invention to provide a system and / or a system module which can at least partially compensate for the disadvantages described above and / or at least partially satisfy the identified need.

[0013] This problem is solved by the present invention. In a first aspect, the present invention relates to a system or system module for treating a metal foil, wherein the system comprises a first roller, a second roller, and a treatment area (also referred to as a processing area) arranged between them. The treatment area has a flat surface over which the metal foil is guided during treatment. The system is configured so that a magnetic field can be generated in the treatment area during treatment. Preferably, the magnetic field can be used to conform the metal foil to the flat surface. This allows a curvature to be removed from the metal foil, preferably without touching a surface of the metal foil to be treated and / or without having to exert significant tensile stresses on the metal foil.

[0014] A flat surface is preferably a planar surface. A surface is preferably flat if all its points lie on the same plane. As will be apparent to the trained reader, flat surfaces in plant engineering are generally subject to manufacturing inaccuracies, which is why a certain tolerance is acceptable. Therefore, the above definition can preferably also be formulated such that a surface is flat if all its points lie in a space between two parallel planes, where the two parallel planes have a distance of at most 2.0 mm, more preferably at most 1.2 mm, more preferably at most 0.8 mm, more preferably at most 0.6 mm, and more preferably at most 0.3 mm from each other. In other words, the flat surface preferably has a flatness of 2.0 mm, more preferably 1.2 mm, more preferably 0.8 mm, more preferably at most 0.6 mm, and more preferably at most 0.3 mm from each other.Preferably, the flatness of the planar surface meets the general tolerance class L, more preferably class K according to DIN ISO 2768-2. The planar surface is preferably a horizontal surface.

[0015] The system is preferably designed such that the metal foil is guided essentially along its longitudinal direction across the flat surface. That is, at least when the system or system module according to the invention is used in a roll-to-roll process, the starting material, here the metal foil, can be unwound from a starting material roll and, if necessary, guided at least over part of the web path before the metal foil reaches the flat surface. The first roll can therefore, at least in some preferred embodiments of the invention, represent the (replaceable) starting material roll (a roll on which the wound starting material is located), or a roll that serves only to guide and / or deflect the metal foil and can therefore preferably be considered part of the web path.As long as the metal foil is wound onto the starting material roll, its longitudinal direction follows a helical path around the central axis of the starting material roll. As those skilled in the art will recognize, the metal foil unwound from the starting material roll along its longitudinal direction still exhibits a curvature, so that the longitudinal direction of the unwound metal foil is not a straight line, but rather a curved line. This curvature can be smoothed out in the area of ​​the flat surface by means of the device according to the invention, in particular by means of the magnetic field, so that in the area of ​​the flat surface the longitudinal direction of the unwound metal foil runs essentially along a straight line. Thus, uniform cross-linking and / or precise printing of the metal foil can preferably be ensured in the treatment area, especially on the flat surface.

[0016] Preferably, one or a combination of the following components and / or materials is arranged beneath the flat surface: bar magnets, disc magnets, ring magnets, neodymium magnets, ferrite magnets, AINiCo magnets, iron, cobalt, nickel. Neodymium magnets are particularly preferably arranged beneath the flat surface in blind holes of a magnetic plate having the flat surface, more preferably at uniform intervals a. In other words, the flat surface is preferably a surface of a magnetic plate. This allows the magnetic field acting on the magnetic plate to be generated and / or adjusted in a cost-effective and / or precise manner. The system preferably includes one or more permanent magnets, particularly neodymium magnets, and / or one or more electromagnets for generating the magnetic field, which are more preferably arranged beneath the flat surface.

[0017] The system preferably comprises at least 20, more preferably at least 50, more preferably at least 80, more preferably at least 100, and more preferably at least 150 magnets for generating the magnetic field (within the area of ​​the flat surface). The flat surface preferably has a width of at least 8 cm, more preferably at least 40 cm. The flat surface preferably has a length of at most 120 cm, more preferably at most 100 cm. The flat surface preferably has a length of at least 20 cm, more preferably at least 25 cm. The magnetic field preferably extends approximately homogeneously over the flat surface. Preferably, the length of the flat surface is defined along a throughput direction or process direction through the treatment area, and the width is perpendicular to the throughput direction, preferably in a horizontal plane.

[0018] The system preferably comprises a plurality of magnets, preferably a plurality of permanent magnets, particularly preferably neodymium magnets, and / or electromagnets for generating the magnetic field, wherein the plurality of magnets is further preferably arranged beneath the flat surface. The plurality of magnets preferably consists of at least 20, more preferably at least 50, more preferably at least 80, more preferably at least 100, and more preferably at least 150 magnets. The magnets of the system for generating the magnetic field (and / or the plurality of magnets is preferably formed by) are preferably round and / or cylindrical magnets, preferably with a diameter (magnet diameter) of 6 to 20 mm, more preferably with a diameter of 10 mm. Preferably, the magnets for generating the magnetic field are arranged in a top view of the flat surface perpendicular to the direction of travel (i.e.,In a 2D view of the magnetic plate, a rotationally symmetric magnetic field is generated around its respective center point. In a three-dimensional view, the magnets preferably form a magnetic field perpendicular to the flat surface (and / or perpendicular to the direction of travel).

[0019] Preferably, the magnets are arranged at least along the direction of travel and / or perpendicular to the direction of travel at uniform intervals a to each other; more preferably, the magnets are arranged in a uniform grid. The distances a between the magnets, i.e., the distance a between two adjacent magnets, are preferably 1.1 to 1.5 times, and more preferably 1.3 to 1.4 times, the magnet diameter. The distances a between the magnets, i.e., the distance a between two adjacent magnets, are preferably between 6.5 mm and 30 mm, and more preferably between 10 mm and 15 mm. The value a is preferably constant in a system. The distance a between two adjacent magnets is preferably measured from the respective centers of the magnets (i.e.,

[0020] Center to center).

[0021] The use of permanent magnets, especially neodymium magnets, is preferred over the use of electromagnets. The inventors were able to demonstrate that permanent magnets represent a good compromise between cost, operational reliability (especially when coating extremely thin films), and maintenance requirements.

[0022] The magnetic field is preferably formed approximately perpendicular to the flat surface. Alternatively and / or additionally preferably, the magnetic field has a minimum holding force of at least 5 N, more preferably at least 30 N, in particular about 32 N, over the entire flat surface and / or a minimum displacement force of at least 1 N, more preferably at least 6 N, in particular about 6.45 N.

[0023] The magnetic field is preferably configured to smooth the metal foil in the area of ​​the flat surface. More preferably, the magnetic field is configured to pull the metal foil towards the flat surface so that the metal foil conforms to the flat surface and / or so that the metal foil assumes the contour of the flat surface. Preferably, the metal foil conforms to the flat surface and / or assumes the contour of the flat surface, disregarding any interruptions in the flat surface, e.g., due to optional blind holes. Preferably, the metal foil in the area of ​​the flat surface has a flatness that corresponds to the flatness of the flat surface.

[0024] Preferably, the magnetic field is stronger on a side of the metal foil facing away from a surface of the metal foil to be treated than on a side of the metal foil that has the surface to be treated.

[0025] Preferably, the coercive field strength bHc at the center of the flat surface, measured perpendicular to the surface, is at least 200 kA / m, more preferably at least 860 kA / m. The energy product at the center of the flat surface, measured perpendicular to the surface, is preferably at least 10 MGOe (mega-Gauss-Oersted), more preferably at least 40 MGOe, more preferably 45 to 55 MGOe, and most preferably 48 to 53 MGOe. As is generally known, the energy product can be determined by the product of the magnetic field strength H and the flux density B. A magnetic field with one or more of the preferred values ​​can preferably contribute to attracting the metal foil strongly enough to the flat surface to remove the curvature from the metal foil and thus flatten it. A suitable adjustment of the magnetic field can additionally contribute to the metal foil still being drawn along the flat surface despite the effect of the magnetic field.The magnetic field can be adjusted so that the metal foil is not attracted so strongly to the flat surface that high tensile forces are required to pull the foil across the surface and thus process it through the treatment area. Preferably, the magnetic field can be adjusted such that a ratio of tensile force in Newtons to metal foil width in mm of a maximum of 0.5 N / mm, preferably a maximum of 0.3 N / mm, and preferably a maximum of 0.2 N / mm is sufficient to pull the metal foil along its longitudinal direction across the flat surface, at least as long as the flat surface does not exceed a length of 30 cm, and the metal foil is a nickel foil with a thickness of 8-100 pm.This makes it possible to successfully smooth and / or process even sensitive and / or thin films within the treatment area of ​​the system.

[0026] The magnetic field can be configured to draw a nickel foil (Ni foil) with a thickness of at least 6 pm onto the flat surface, provided that the distance to the flat surface is no more than 2.0 mm, preferably no more than 5.0 mm. More preferably, the magnetic field is configured to draw a nickel foil with a thickness of at most 100 pm, preferably no more than 10 pm, onto the flat surface, provided that the distance to the flat surface is no more than 2.0 mm, preferably no more than 5.0 mm. Thus, the treatment system can be optimized, in particular, for processing thin metal foils. Preferably, the treatment system is optimized for flexible metal foils with a ceramic coating.

[0027] The flat surface is preferably provided with a sliding layer. More preferably, the sliding layer may be made of PTFE. The sliding layer facilitates the easy pulling of the metal foil across the flat surface without exerting significant or high tensile forces on the metal foil. Particularly preferably, no high tensile forces are exerted on the metal foil if the ratio of tensile force in Newtons to the metal foil width in millimeters is a maximum of 0.5 N / mm, preferably a maximum of 0.3 N / mm, and most preferably a maximum of 0.2 N / mm.

[0028] The system can further include a carrier belt, the carrier belt preferably being movable along the flat surface by means of the first and / or second roller. More preferably, the carrier belt can wrap around the first and second rollers, in other words, be arranged circumferentially around them. If the carrier belt is movable along the flat surface by means of the first and / or second roller, it may be advantageous to design the corresponding first and / or second roller primarily for this purpose and, if necessary, not to assign it to the system's web path. In particular, if the first roller serves to deflect the carrier belt, the first roller cannot simultaneously be the starting material roller. In other words, when using a carrier belt, it is necessary that the starting material is wound onto a starting material roller that is not the first roller.The starting material roll itself is generally not part of the system module according to the invention. At least part of the carrier strip can be arranged above the flat surface and / or in contact with the flat surface. The use of such a carrier strip can help to further minimize tensile forces acting on the metal foil during the process and is therefore particularly advantageous for the treatment of sensitive metal foils. The carrier strip preferably comprises PTFE. More preferably, the carrier strip can be a PTFE film. A surface of the carrier strip can be designed to come into contact with the metal foil to be treated.When a carrier tape is used, the magnetic field is preferably configured to pull the metal foil, preferably together with the carrier tape, towards the flat surface, so that the metal foil and preferably also the carrier tape conform to the flat surface and / or so that the metal foil and preferably also the carrier tape take on the contour of the flat surface.

[0029] The treatment area can be configured, in at least one preferred embodiment, to treat the surface of a metal foil using a wet chemical process. Preferably, the treatment area and / or the system is designed to ensure uniform wetting of the metal foil surface to be treated, in particular by allowing the metal foil to be processed flat along its flat surface through the treatment area.

[0030] The treatment area may include a treatment unit designed to treat a surface of the metal foil, preferably using wet chemical treatment.

[0031] Preferably, the magnetic field is stronger on one side of the metal foil and / or the flat surface facing away from the treatment unit than on the other side. If, for example, permanent magnets are used to generate the magnetic field, the permanent magnets are preferably arranged on one side of the flat surface, for example, below the flat surface, and the treatment unit is more preferably arranged on the opposite side of the flat surface, for example, above the flat surface. The system is preferably configured to guide the metal foil in the treatment area over the flat surface and / or through an area between the permanent magnets and the treatment unit.

[0032] Preferably, the system is set up and designed so that it does not mechanically touch the surface of the Meta I Ifolie to be treated in the treatment area.

[0033] Preferably, the system is designed for use in roll-to-roll production and / or in a roll-to-roll process. The first and / or the second roll can be a driven roll or a free-rotating roll. The first and the second roll, in particular their axes of rotation, can preferably extend perpendicular to a process direction. In other words, the axes of rotation of the first and the second roll can be oriented parallel to a direction along which the width of the planar surface is defined, and / or perpendicular to a direction along which the length of the planar surface is defined. In particular, preferably only the first or the second roll can be a driven roll, and the other roll can be a free-rotating roll.Alternatively, preferably, both the first and second rollers can be freely rotatable, and the system can be used in conjunction with other rollers, particularly in roll-to-roll production, wherein one of the other rollers is driven and thus the metal film can be processed through the treatment area by means of this driven roller.

[0034] In a further aspect, the present invention relates to a method for treating the surface of a metal film in a system comprising a first roller, a second roller, and a treatment area extending at least partially between the first and second rollers, wherein the treatment area has a flat surface; and / or a method for treating the surface of a metal film in a system according to one or more of the above-mentioned features, wherein the method comprises:

[0035] a. Introducing the metal foil into the process area of ​​the plant;

[0036] b. Smoothing the metal foil in the treatment area by means of a magnetic force which attracts the metal foil to the flat surface;

[0037] c. Treating the smoothed metal foil in the treatment area. A magnetic field responsible for the magnetic force in process step b. can be formed approximately perpendicular to the flat surface. The magnetic field can have a minimum holding force of at least 5 N, preferably at least 30 N, particularly about 32 N, over the entire flat surface and / or a minimum displacement force of at least 1 N, more preferably at least 6 N, particularly about 6.45 N.

[0038] Preferably, in process step b., the coercive field strength bHc at the center of the planar surface, measured perpendicular to the surface, can be at least 200 kA / m, preferably at least 860 kA / m. The energy product at the center of the planar surface, measured perpendicular to the surface, in process step b. is preferably at least 10 MGOe (mega-Gauss-Oersted), further preferably at least 40 MGOe, further preferably 45 to 55 MGOe, and particularly preferably 48 to 53 MGOe.

[0039] Preferably, the method also includes one or more of the following steps:

[0040] d. Wet chemical treatment of the surface of the metal foil in the treatment area, preferably during process step c.;

[0041] e. Continuing the metal foil, preferably using the first and / or second roll.

[0042] In step c. of the process, the metal foil, in particular the part of the metal foil located on the flat surface, preferably has a flatness of at least 1 mm, more preferably at least 0.5 mm.

[0043] Preferably, the metal foil is not mechanically held down during treatment in the inventive method. Preferably, the surface of the metal foil to be treated is not mechanically touched during treatment in the inventive method.

[0044] In a further aspect, the present invention relates to a system comprising the apparatus according to one or more of the preceding features and a metal foil. The metal foil is preferably a nickel foil (Ni foil). Preferably, the metal foil has a thickness of 8 to 100 pm. More preferably, the metal foil has a thickness of at most 100 pm, more preferably at most 50 pm, and more preferably at most 10 pm. Preferably, the metal foil has a ceramic coating. Preferably, the metal foil is flexible.

[0045] Using the inventive method and / or the inventive apparatus and / or the inventive system, it is possible to process very thin and / or sensitive metal foils in a roll-to-roll process within a treatment area, ensuring that the metal foil has a flat geometry in the treatment area, so that – particularly in the case of wet chemical surface treatment – ​​uniform wetting of the metal foil surface can occur. Furthermore, it can be ensured that the metal foil is not subjected to significant tensile forces during the process in the process area, and that the surface of the metal foil to be treated is not mechanically contacted, at least in the treatment area. Therefore, the described apparatus and / or the described method is particularly suitable for the treatment of extremely sensitive and / or thin metal foils.Furthermore, such a system allows for the efficient and / or high-quality application of sensitive coatings. Additionally, wet chemical processes, including those involving toxic substances and / or solvents, can be used in such a system and / or process, as the film is not smoothed by flow mechanisms in the treatment area. This reduces the amount of exhaust air from such a system, which would otherwise require complex cleaning.

[0046] The invention relates in particular to the following aspects:

[0047] 1. A system for treating a metal foil, wherein the system comprises a first roll, a second roll and a treatment area arranged in between, the treatment area having a flat surface over which the metal foil is guided during treatment, and the system being configured to generate a magnetic field in the treatment area during treatment.

[0048] 2. System according to aspect 1, wherein one or a combination of the following components and / or materials is / are arranged below the flat surface: bar magnets, disc magnets, ring magnets, neodymium magnets, ferrite magnets, AINiCo magnets, iron, cobalt, nickel; wherein neodymium magnets are preferably arranged below the flat surface in blind holes of a magnetic plate having the flat surface.

[0049] 3. System according to aspect 1 or 2, wherein the system for generating the magnetic field comprises one or more permanent magnets and / or one or more electromagnets, which are preferably arranged under the flat surface.

[0050] 4. A system according to one of the above aspects, wherein the flat surface has a width between 8 cm and 120 cm, and / or wherein the flat surface has a length of at least 20 cm, more preferably at least 30 cm, wherein the magnetic field preferably extends approximately homogeneously over the flat surface.

[0051] 5. System according to one of the above aspects, wherein the magnetic field is formed approximately perpendicular to the flat surface and / or wherein the magnetic field over the entire flat surface has a minimum holding force of at least 5 N, preferably at least 30 N and a minimum displacement force of at least 1 N, preferably at least 6 N.

[0052] 6. Investment according to one of the above aspects, wherein

[0053] the coercive field strength in the center of the planar surface, measured perpendicular to the surface, is at least 200 kA / m, preferably at least 860 kA / m, and / or the energy product in the center of the planar surface, measured perpendicular to the surface, is at least 10 MGOe, preferably at least 40 MGOe.

[0054] 7. A system according to one of the above aspects, wherein the magnetic field is set up to draw a Ni foil with a thickness of at least 6 pm and / or a maximum of 100 pm onto the flat surface, provided that a distance between the flat surface is no more than 5.0 mm, preferably no more than 2.0 mm.

[0055] 8. A system according to one of the above aspects, wherein the flat surface is horizontally oriented and wherein the system is preferably designed to be used in roll-to-roll production.

[0056] 9. A system according to any of the foregoing aspects, wherein the first and / or the second roller is a driven roller or a freely rotating roller, and wherein the first and the second roller preferably extend perpendicular to a process direction. 10. A system according to any of the foregoing aspects, wherein the flat surface is provided with a sliding layer, wherein the sliding layer preferably comprises PTFE.

[0057] 11. A system according to one of the above aspects, further comprising a support belt, wherein the support belt is movable along the flat surface by means of the first and / or second roller.

[0058] 12. System according to aspect 11, wherein at least a part of the carrier strip is arranged above the flat surface and preferably in contact with the flat surface, wherein the carrier strip is preferably arranged circumferentially around the first and the second roller. 13. System according to aspect 11 or 12, wherein the carrier strip comprises PTFE, preferably wherein the carrier strip is a PTFE film; and / or wherein a surface of the carrier strip is formed to come into contact with the magnetic metal film to be treated.

[0059] 14. A system according to one of the above aspects, wherein the treatment area is designed to treat a surface of a metal film using wet chemicals.

[0060] 15. Method for treating a surface of a meta I Ifo in a system comprising a first roller, a second roller and a treatment area extending at least partially between the first and second rollers, wherein the treatment area has a flat surface, preferably in a system according to one of the above aspects, wherein the method comprises:

[0061] a. Introducing the metal foil into the process area of ​​the plant;

[0062] b. Smoothing the metal foil in the treatment area by means of a magnetic force, which attracts the metal foil to the flat surface; and

[0063] c. Treating the smoothed metal foil in the treatment area.

[0064] 16. Procedure according to aspect 15, further comprising one or more of the following steps:

[0065] d. Wet chemical treatment of the surface of the metal foil in the treatment area, preferably during process step c.; and e. Continuing the metal foil using the second roll.

[0066] 17. Method according to aspect 15 or 16, wherein in step c. the metal foil, in particular the part of the metal foil located on the flat surface, has a flatness of at least 1 mm, preferably at least 0.5 mm.

[0067] 18. Method according to one of aspects 15 to 17, wherein the metal foil is not mechanically held down during the treatment.

[0068] 19. A method according to any one of aspects 15 to 18, wherein a magnetic field causing the magnetic force in process step b. is formed approximately perpendicular to the planar surface and / or wherein the magnetic field causing the magnetic force in process step b. has a minimum holding force of at least 5 N, preferably at least 30 N, and a minimum displacement force of at least 1 N, preferably at least 6 N, over the entire planar surface. 20. A method according to any one of aspects 15 to 19, wherein in process step b. the coercive field strength at the center of the planar surface, measured perpendicular to the surface, is at least 200 kA / m, preferably at least 860 kA / m, and / or the energy product at the center of the planar surface, measured perpendicular to the surface, is at least 10 MGOe, preferably at least 40 MGOe.

[0069] 21. System comprising a device according to one of aspects 1 to 14 and a metal foil, wherein the metal foil preferably has a thickness of 8 to 100 pm and further preferably wherein the metal foil has a ceramic coating. A preferred embodiment of the invention is described below by way of example with reference to the figures below. The figures show:

[0070] Fig. 1 shows a schematic representation of a system according to the invention in a first preferred embodiment in a side view; and Fig. 2 shows a schematic representation of a system according to the invention in a second preferred embodiment in a side view.

[0071] Figure 1 schematically depicts a system or system module 1 for treating a metal foil according to a first preferred embodiment of the invention. The system module 1 has a treatment area 100 in its center, in which a flat surface, here formed on a magnetic plate 60, is located. In the illustrated embodiment, the flat surface is a horizontal surface; that is, the magnetic plate 60 has a horizontal flat surface. The magnetic plate 60, and in particular the flat surface, extends approximately along the entire treatment area 100. The treatment area 100 is bounded by a first roller 40 and a second roller 70, which are arranged on a first and a second side of the magnetic plate 60 opposite it in the longitudinal direction. In the illustrated embodiment, the first roller 40 and the second roller 70 are arranged outside the treatment area 100.Depending on the specific design of the system, the first roller 40 and the second roller 70 can also be located in the treatment area 100. In the illustrated embodiment, a sliding layer 90 is applied to the magnetic plate 60, in particular to the flat surface. In the illustrated embodiment, the sliding layer 90 is made of PTFE. In alternative embodiments, other materials or material combinations can, of course, be used to form the sliding layer 90. The choice of material and / or material composition of the sliding layer can depend on the process to be carried out in the treatment area, the properties of the material to be processed, e.g., a metal foil to be processed, and / or environmental conditions. Depending on the individually given system parameters, suitable materials for the sliding layer 90 can be found in the prior art. The purpose of the sliding layer 90 is to provide a simple, i.e.,to ensure the least possible resistance sliding of the material to be processed, e.g. a metal foil to be processed, over the magnetic plate 60.

[0072] The illustrated system module 1 is designed for use in a roll-to-roll process. In this process, feed material can be unwound from a feed material roll 20 and fed to the system module 1, in particular to the processing area 100. The illustrated system module 1 is designed for processing magnetic feed material, specifically a metal foil 10. The metal foil 10 is a thin metal foil, i.e., a metal foil with a thickness of less than 100 µm. The metal foil 10 is preferably provided in the form of a continuous web, i.e., a web several meters long, which is wound onto the feed material roll 20.In the roll-to-roll process, the metal foil 10 is unwound from the starting material roll 20 and guided, preferably along a web path (not fully shown), through at least the treatment area 100, and preferably also through further upstream and / or downstream treatment areas (not shown). According to the invention, the system module 1 has a first roll and a second roll. In principle, the first roll can be a roll arranged upstream of the treatment area 100 and correspond to the starting material roll 20, and the second roll can be a roll arranged downstream of the treatment area 100 and either be part of the web path or represent a target roll onto which the metal foil is rewound. In the embodiment shown, however, the system module 1 has a first roll 40 and a second roll 70, both of which can be considered part of the web path.In addition to the first roll 40 and the second roll 70, a separate starting material roll 20 is schematically shown in Fig. 1. This starting material roll 20 can also be assigned to system module 1 or be part of another system module. The boundaries between individual system modules may be fluid. Furthermore, a third roll 110 is schematically shown in Fig. 1, which is also part of the web path and does not necessarily have to be assigned to system module 1. As should be apparent to those skilled in the art, the representation in Fig. 1 is to be understood as merely schematic. Of course, in an actual system according to the present invention, further system modules and / or rolls of the web path can be provided, particularly in the areas between the starting material roll 20 and the first roll 40 and / or between the second roll 70 and the third roll 110.

[0073] It is known that in such systems, a respective section of the metal foil 10, unwound from the starting material roll 20, exhibits a curvature 30. This means that, in its unwound state, the respective section of the metal foil 10, when viewed in its longitudinal direction (corresponding here to the direction of travel through the system) and / or transverse direction, does not extend along a straight line, but rather along a curved line – at least as long as no external forces other than gravity act on the section. Figure 1 schematically illustrates this in two sections of the metal foil 10 as curvature 30 and curvature 80. This curvature is disadvantageous if the metal foil in the treatment area 100 is to be uniformly wetted, for example, during a wet chemical surface treatment.For this reason, the treatment area 100 is designed according to the invention in such a way that at least a large part of the section of the metal foil 10 which passes through the treatment area 100 is smoothed in the treatment area 100 in order to be able to process the smoothed area in the best possible way, for example to wet it evenly.

[0074] The treatment area 100 is designed such that the starting material, here the metal foil 10, can be guided through it, particularly during the roll-to-roll process. When the system module 1 is operating, the metal foil 10 slides over the magnetic plate 60 or on the sliding layer 90 through the treatment area 100. Before entering the treatment area 100, the metal foil 10 is guided over the first roller 40, and after exiting the treatment area 100, it is guided over the second roller 70. The metal foil is preferably guided through the treatment area 100 by an active rotary motion of the starting material roller 20, the first roller 40, the second roller 70, and / or another upstream or downstream roller, such as roller 110. This means that at least one of the rollers in the web path is driven to process the metal foil 10 through the system; in this case, the second roller 70.

[0075] A magnetic field can be generated in the treatment area 100, thereby energizing the magnetic plate 60. The magnetic plate 60 is therefore magnetic or at least magnetizable. In a preferred embodiment, the magnetic plate 60 can have a substantially flat surface into which blind holes are machined, with neodymium magnets being inserted into these blind holes. This substantially flat surface with the blind holes then preferably forms the planar surface. If a flatness requirement is specified for the planar surface, the blind holes are preferably disregarded when determining the flatness. The magnetic field is generated by the neodymium magnets in the area directly on or above the planar surface.When the metal foil 10, particularly during the roll-to-roll process, runs over the flat surface of the magnetic plate 60, the section of the metal foil 10 located on the flat surface is attracted to the magnetic plate 60, i.e., pressed onto the flat surface by magnetic forces. This section of the metal foil 10 thus conforms to the flat surface. This results in any bulges present in the section of the metal foil 10 located on the magnetic plate 60 before it enters the treatment area 100 being smoothed out. The metal foil 10 therefore has a substantially flat surface in the treatment area 100, more precisely in the area of ​​the magnetic plate 60. In other words, the surface of the metal foil 10 in the area of ​​the magnetic plate 60 is free of bulges; preferably, the surface of the metal foil 10 in this area runs parallel to the flat surface of the magnetic plate 60.

[0076] Preferably, a surface treatment, in particular a wet chemical surface treatment, is carried out on the metal foil 10 in treatment area 100. The system module according to the invention ensures that the section of the metal foil 10 located on the flat surface and subjected to surface treatment is smoothed, i.e., in particular, that it has no curvature or at least that the curvature of the metal foil 10 caused by unwinding is significantly reduced. This ensures uniform wetting and thus high-quality surface treatment. The smoothing of the metal foil 10 is carried out without mechanically contacting and / or significantly stressing the surface of the metal foil 10 to be treated, in this case, the surface facing upwards in treatment area 100.Only the opposite side of the metal foil, in this case the underside, comes into contact with the magnetic table 60 and is drawn across it. This underside is generally much less sensitive, which is why drawing it across the sliding layer 60 does not usually damage the metal foil 10 or the quality of the surface treatment. After the processed section of the metal foil 10 has passed through the treatment area 100 and is thus no longer exposed to the influence of the magnetic table 60, this section of the metal foil 10 will warp again, as should be obvious to those skilled in the art. However, this does not impair the quality of the surface treatment. The renewed warping after passing through the treatment area 100 is schematically indicated in Figure 1 by the warp 80. After passing through the treatment area 100, the metal foil 10 can, if necessary, be further processed in other adjacent system modules.Preferably, the plant module shown can be suitable for processing an infinitely long metal foil 10, wherein the section of the metal foil 10 which is in contact with the magnetic plate 60 or the sliding layer 90 always has a smoothed, preferably flat surface in order to be processed in the treatment area 100.

[0077] As should be apparent to those skilled in the art, such a treatment area 100 with a flat surface and magnetic field, as realized here by magnetic plate 60, can be used not only in roll-to-roll processes but also in other production areas where it is required to hold and / or convey a metal foil and / or a thin metal sheet as flat as possible and without mechanically contacting a surface of the metal foil or sheet facing away from the magnetic plate 60. The system module 1 does not, of course, have to be oriented as shown, such that a section of the metal foil 10 passes through the treatment area 100 essentially horizontally, even though such an orientation is preferred, particularly for the application of coatings. In alternative embodiments, the flat surface or the magnetic table 60 can also be arranged at an angle to the horizontal plane.

[0078] Figure 2 shows a system module 1' in a further preferred embodiment of the present invention. The system module 1' is essentially identical in construction to the system module 1. However, unlike the system module 1 of the first preferred embodiment, the system module 1' does not merely use a sliding layer 90 applied to the magnetic plate 60, but rather a carrier strip 50 arranged circumferentially around the magnetic plate 60. The carrier strip 50 can have the sliding layer 90 and / or be made of the same material as the sliding layer 90. In any case, it is advantageous for the carrier strip 50 to be provided with a sliding layer on its outwardly facing surface, preferably with a PTFE layer. The carrier strip 50 can preferably be a PTFE strip. The carrier strip runs over the magnetic plate 60 in at least a portion of the treatment area 100.The carrier belt 50 preferably encircles the first roller 40 and the second roller 70 and is driven by the second roller 70, so that the carrier belt 50 can preferably move at the same speed as a metal foil 10, which is conveyed through the treatment area 100. The metal foil 10 can therefore either also be conveyed by means of the driven second roller 70 or by means of the carrier belt 50, or by means of another driven roller, for example by means of the third roller 110 or the input material roller 20. As can be seen, in this embodiment the first roller cannot directly also serve as the input material roller, but an additional input material roller 20 is necessarily required, which, however, is not necessarily part of the system module 1'.

[0079] The system module 1' is also designed for use in a roll-to-roll process. This means that, in this embodiment as well, the starting material, here the metal foil 10, is first unwound from the starting material roll 20, so that the metal foil 10 initially has a curved surface or curvature 30. The treatment area 100 is designed such that the metal foil 10 can be guided through it. However, during operation of the system module 1, the metal foil 10 does not slide directly over the magnetic plate 60 as in the system module 1, but rather, upon entering the treatment area, preferably in the area of ​​the first roll 40, the metal foil 10 comes into contact with the carrier belt 50. After exiting the treatment area 100, the metal foil 10 preferably also leaves the carrier belt 50, preferably in the area of ​​the second roll 70.

[0080] In the treatment area 100, the magnetic plate 60 arranged under the carrier belt 50 acts on the metal foil 10, so that, as in the first embodiment, a magnetic field is formed in the treatment area 100 which presses the metal foil 10 towards the magnetic plate 60 and onto the carrier belt 50 by means of magnetic forces. Thus, the metal foil 10 is smoothed in the treatment area 100. In other words, the metal foil 10 has a smooth, preferably flat, surface in a section where it is in contact with the carrier belt 50. This can be ensured by having the flat surface formed on the magnetic plate 60 arranged under the carrier belt 50 and / or by having the carrier belt 50 itself have the flat surface.

[0081] The carrier belt 50 can be moved at the same speed as the metal foil 10. This prevents any relative movement between the metal foil 10 and the carrier belt 50 in the treatment area 100. The metal foil 10 can therefore be processed particularly gently. Specifically, although the carrier belt 50 does contact the underside of the metal foil 10 in the treatment area 100, this underside is not moved along a sliding surface. This ensures that the frictional forces acting on the metal foil 10 relative to the system module 1 are reduced in all cases. The carrier belt 50 preferably slides over the magnetic plate 60. This can lead to wear on the carrier belt. Therefore, it is preferred that the carrier belt be arranged in the system module 1' in such a way that it is easily replaceable. The system module 1' thus differs primarily from the system module 1 in that a carrier belt 50 is provided instead of the sliding layer 90.The further structural features of the plant module according to the invention and / or adjacent plant modules can preferably be identical to those of the first preferred embodiment. A detailed description is therefore omitted here.

[0082] The embodiments shown illustrate a preferred embodiment of the method according to the invention. The metal foil 10 is first introduced into the treatment area 100 by means of rotatable rollers, for example, the driven roller 70 (step a.), or drawn through the treatment area 100. In the treatment area, the metal foil is smoothed, preferably by the magnetic forces acting on the metal foil 10 from the magnetic plate 60, so that the metal foil 10 is drawn onto a flat surface of the magnetic plate 60 (step b.). The metal foil is preferably smoothed such that it has a flatness of up to 1 mm, preferably up to 0.5 mm, in the area of ​​the magnetic plate 60. In the treatment area 100, the smoothed metal foil can be processed, for example, surface-treated (step c.).Using such a method, particularly sensitive metal foils can be processed and / or surface-treated without mechanically stressing the surface of the metal foil and / or without applying excessive tensile forces to the metal foil to achieve smoothing through tensile force. Naturally, steps a, b, and c are carried out simultaneously in a continuous process with respect to different sections of the metal foil.

[0083] The present invention is characterized in particular by the fact that the metal foil 10 can be smoothed by means of magnetic forces, which press the metal foil 10 against a flat surface of a magnetic plate 60 in such a way that the metal foil is smoothed, that is, preferably has a similar, and more preferably (theoretically ideal) the same flatness as the flat surface of the magnetic plate 60. The metal foil 10 is drawn over the magnetic plate 60 in order to pass it through the treatment area 100. The tensile force required to draw the metal foil 10 through the treatment area 100 and, for example, over the sliding surface 90, is significantly less than a tensile force that would be required to smooth the metal foil 10 without the smoothing occurring due to magnetic forces.Should the tensile forces required to pull the metal foil over the sliding surface 90 be too high for, for example, a very thin metal foil 10, or should the metal foil 10 be so sensitive that relative movement between an underside of the metal foil 10 and a system component is unacceptable, the second preferred embodiment can be used, wherein relative movement of the metal foil 10 to the system component can be completely prevented by using the carrier band 50.

[0084] Preferably, a plant module 1, l' according to the invention can be installed in a roll-to-roll production plant. Then, for example, the metal foil 10 can be conveyed in the roll-to-roll production plant over the magnetic plate 60 after being smoothed and treated in the treatment area 100. In adjacent plant modules, the metal foil 10 can be conveyed again over rollers and thereby regain its inherent curvature without disturbing the surface treatment in plant module 1.

[0085] The described invention thus provides a system module that can contribute in a relatively simple manner to the processing of a magnetic starting material, here a metal foil 10, particularly in a roll-to-roll process, in a treatment area 100, thereby ensuring precise and / or uniform processing of the foil surface, for example, uniform wetting of the metal foil. Furthermore, it can prevent damage to particularly sensitive metal foils caused by strong tensile stress and / or mechanical stress on the surface.

[0086] The figures shown describe only exemplary preferred embodiments of the invention. The invention in its entirety is defined in the claims below.

Claims

Claims 1. A system for treating a metal foil, wherein the system comprises a first roll, a second roll and a treatment area arranged in between, the treatment area having a flat surface over which the metal foil is guided during treatment, and the system being configured to generate a magnetic field in the treatment area during treatment.

2. System according to claim 1, wherein one or a combination of the following components and / or materials is / are arranged below the flat surface: bar magnets, disc magnets, ring magnets, neodymium magnets, ferrite magnets, AINiCo magnets, iron, cobalt, nickel; wherein neodymium magnets are preferably arranged below the flat surface in blind holes of a magnetic plate having the flat surface.

3. System according to claim 1 or 2, wherein the system for generating the magnetic field comprises one or more permanent magnets and / or one or more electromagnets, which are preferably arranged under the flat surface.

4. System according to one of the preceding claims, wherein the flat surface has a width between 8 cm and 40 cm, and / or wherein the flat surface has a length of at least 20 cm, more preferably at least 120 cm, wherein the magnetic field preferably extends approximately homogeneously over the flat surface.

5. System according to one of the preceding claims, wherein the magnetic field is formed approximately perpendicular to the planar surface and / or wherein the magnetic field over the entire planar surface has a minimum holding force of at least 5 N, preferably at least 30 N and a minimum displacement force of at least 1 N, preferably at least 6 N.

6. System according to one of the preceding claims, wherein the coercive field strength in the center of the planar surface, measured perpendicular to the surface, is at least 200 kA / m, preferably at least 860 kA / m, and / or the energy product in the center of the planar surface, measured perpendicular to the surface, is at least 10 MGOe, preferably at least 40 MGOe.

7. Apparatus according to one of the preceding claims, wherein the magnetic field is configured to attract a Ni foil with a thickness of at least 6 pm and / or a maximum of 100 pm to the flat surface, provided that a distance between the flat surface is no more than 5.0 mm, preferably no more than 2.0 mm.

8. System according to one of the preceding claims, wherein the flat surface is horizontally oriented and wherein the system is preferably designed to be used in roll-to-roll production.

9. Device according to one of the preceding claims, wherein the flat surface is provided with a sliding layer, wherein the sliding layer preferably comprises PTFE.

10. System according to one of the preceding claims, further comprising a carrier belt, wherein the carrier belt is movable along the flat surface by means of the first and / or second roller.

11. System according to claim 10, wherein at least a part of the carrier tape is arranged above the flat surface and is in contact with the flat surface, wherein the carrier tape is preferably arranged circumferentially around the first and the second roller.

12. System according to claim 10 or 11, wherein the carrier tape comprises PTFE, preferably wherein the carrier tape is a PTFE film; and / or wherein a surface of the carrier tape is formed to come into contact with the magnetic Meta I I film to be treated.

13. Apparatus according to one of the preceding claims, wherein the treatment area is configured to treat a surface of a metal film using wet chemical methods.

14. Method for treating a surface of a meta I Ifo in a system comprising a first roller, a second roller and a treatment area extending at least partially between the first and the second roller, wherein the treatment area has a flat surface, preferably in a system according to one of the preceding claims, wherein the method comprises: a. Introducing the metal foil into the process area of ​​the plant; b. Smoothing the metal foil in the treatment area by means of a magnetic force, which attracts the metal foil to the flat surface; and c. Treating the smoothed metal foil in the treatment area.

15. The method of claim 15, further comprising one or more of the following steps: f. Wet chemical treatment of the surface of the metal foil in the treatment area, preferably during process step c.; and g. Continuing the metal foil using the second roll.

16. Method according to claim 15 or 16, wherein in step c. the metal foil, in particular the part of the metal foil located on the flat surface, has a flatness of at least 1 mm, preferably at least 0.5 mm.

17. System comprising a device according to any one of claims 1 to 13 and a metal foil, wherein the metal foil preferably has a thickness of 8 to 100 pm and further preferably, wherein the metal foil has a ceramic coating.

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