Device, use and method for dosing or levelling

Abstract

The invention relates to a device and method for dosing or levelling a liquid or pasty application medium onto a moving surface, said device comprising a dosing element for contacting the application medium in a contact zone, and a pressing unit for pressing the dosing element against the moving surface, wherein the dosing element consists wholly or partly of a magnetic or ferromagnetic material, and the device also comprises at least one magnetic element which is positioned in such a way that the magnetic force between the pressing unit and the contact zone, in particular in the region of the contact zone, acts on the dosing element.

Description

[0001] Device, use and method for dosing or equalizing

[0002] The invention relates to a device for dosing or leveling a liquid or pasty application medium onto a moving surface according to the preamble of claim 1, as well as to an associated method and use.

[0003] When finishing fibrous webs, such as coating or sizing paper, board, and packaging webs, liquid or pasty application media are often applied as thin, fluid films to the fibrous web or a transfer surface. These film thicknesses typically range from 1 μm to 100 μm. Both volumetric and hydrodynamic dosing principles can be used to meter these application media.

[0004] For dosing, the dosing devices known from EP1761341 B1 and WO 02 / 27097, for example, can be used. In volumetric dosing, grooved metering rods are used, while smooth metering rods are used for hydrodynamic dosing. Metering blades, as shown in WO 02 / 27097, can also be used for dosing. While in volumetric dosing the metering rod touches the application surface, in hydrodynamic dosing the metering rod or blade floats without touching the application surface (aquaplaning effect). However, both dosing principles can also be implemented in other ways. For example, blades can also be used as metering elements for hydrodynamic dosing.

[0005] What all hydrodynamic metering elements have in common is that they are not in direct contact with the substrate because the hydrodynamic metering element floats on the liquid film (as in aquaplaning) without it touching the surface of the application roller or the substrate.

[0006] Volumetric dosing is primarily used when the application fluids have a very low shear viscosity (e.g., < 200 mPas Brookfield at 100 rpm) or when the machine speeds are so low (< 1000 m / min) that the available hydrodynamic dosing elements cannot generate sufficient hydrodynamics for film formation. Volumetric dosing processes are also used when larger film thicknesses (> 25 pm) must be applied directly or indirectly to the fibrous web.

[0007] Hydrodynamic dosing processes are or can only be used when the application medium has a high low shear viscosity (e.g. > 800 mPas Brookfield) or a high high shear viscosity (e.g. > 80 mPas, capillary viscometer at high shear rates > 1.E-05). To use hydrodynamic dosing, the geometry of the dosing element must be designed in such a way that it can generate sufficient hydrodynamic pressure beneath the dosing element to allow the liquid film to form with the desired film thickness. The greater the contact length between the liquid and the dosing element, the greater the hydrodynamics generated beneath the dosing element. The higher the machine speed or the higher the viscosity, the more hydrodynamics are generated, allowing a wide working window for adjusting and controlling the wet film thickness.

[0008] A common and increasingly economically relevant application for film application is the application of starch (sizing) using a film press. A film of starch is metered onto the surface of a transfer roller, which is then transferred to the fiber web in a transfer nip. Especially for the sizing of packaging paper, there is a trend toward using transfer rollers with harder surfaces. Such film presses are described, for example, in DE102018100924 A1.

[0009] In such applications, the situation often arises that, at low production speeds and / or with the technologically necessary low viscosities of starch solutions, the desired wet film thicknesses cannot be achieved with hydrodynamic metering elements. These required film thicknesses can only be achieved with volumetric metering elements. However, volumetric metering elements must be in direct contact with the application surface, in this case the transfer roller. This causes the metering elements or the transfer rollers to wear very quickly. This can also create negative marks in the application pattern on the substrate.

[0010] The object of the invention is to overcome the limitations of hydrodynamic dosing elements.

[0011] It is a particular object of the invention to propose hydrodynamic metering elements which have a significantly larger range of applications compared to the prior art.

[0012] It is a further object of the invention to expand the range of applications of film presses, particularly in the field of hard nip sizing.

[0013] Unless explicitly stated otherwise, in this application the viscosity of the application medium always refers to the “high shear viscosity”, measured with the capillary viscometer at high shear rates > 1.E-05.

[0014] The object is achieved according to the invention by a device according to independent claim 1 and a method according to claim 14. Further advantageous embodiments of the present invention can be found in the subclaims.

[0015] With regard to the device, the object is achieved by a device for dosing or leveling a liquid or pasty application medium onto a moving surface. The device comprises a dosing element for contacting the application medium in a contact zone, as well as a pressing unit for pressing the dosing element against the moving surface. According to the invention, the dosing element consists entirely or partially of a magnetic material, in particular a ferromagnetic material, and that the device further comprises at least one magnetic element which has a repulsive or attractive effect on the dosing element. In one embodiment, the magnetic element can be arranged such that the magnetic force acts on the dosing element between the pressing unit and the contact zone, in particular in the region of the contact zone.In this embodiment, it is advantageous if the at least one magnetic element is designed such that the magnetic force counteracts the contact force of the contact unit and, in particular, the magnetic force has an attractive effect on the dosing element. The magnetic force acts as a return force for the dosing element.

[0016] In a further embodiment, the magnetic force can be provided to repel the dosing element, completely or partially assuming the function of the pressure unit. In such embodiments, it is advantageous to provide a return force for the dosing element that counteracts the repulsive magnetic force. This can be achieved via return means such as a pre-tensioned or bent elastically resilient blade, a pre-tensioned elastically resilient holder for the metering rod, or similar means.

[0017] In designs with repulsive magnetic elements, the magnetic force is essential for the functioning of the dosing device. The repulsive magnets act as the pressure unit. By varying the magnetic force, the pressure of the dosing element can be regulated. A return force, for example, via a pre-tensioned or bent elastically resilient blade or a pre-tensioned elastically resilient metering rod holder, can be influenced and finely regulated by changing the repulsive magnetic force. This design is therefore very advantageous because the dosing device requires few mechanical parts and is therefore simple and inexpensive to manufacture.

[0018] Dosing elements that can be used are elements known from the prior art, such as dosing blades or dosing elements with metering rods. Smooth, non-grooved metering rods are advantageously used. The metering rods can be hard or soft, and their surface can consist of, for example, rubber, polyurethane, or metal. Dosing blades are advantageous for use in a device according to aspects of the invention, as they are often already made of a magnetic or ferromagnetic material. However, such magnetic or ferromagnetic elements can also be very easily attached to metering devices with metering rods.

[0019] As with the dosing devices known from the prior art, the contact force with which the dosing element is pressed against the moving surface can also be adjusted within the scope of the invention essentially via the contact pressure unit. These contact pressure units are typically mechanical contact pressure units, whereby the contact pressure can be generated, for example, by means of adjusting screws, a contact pressure hose, or by deflection.

[0020] Particularly when using dosing blades as dosing elements, the blade geometry such as the blade deflection and the position of the contact zone can also be adjusted using the pressure unit.

[0021] The contact zone is the area where the dosing element is in contact with the application medium or the area where the hydrodynamic force acts on the dosing element.

[0022] The inventor has recognized that by adding a magnetic field (for example in the form of one or more magnetic elements), particularly in the area of ​​this contact zone, the contact force can be influenced very precisely and specifically, in particular reduced.

[0023] This allows for a significantly expanded application range, especially for hydrodynamic metering elements. For the described "aquaplaning effect" to occur, the force generated by the hydrodynamics must be large enough to compensate for the contact pressure of the metering element. This is not possible in many relevant applications due to the low speed or the low viscosity of the application medium.

[0024] However, reducing the contact force would result in a change in the blade geometry, which is generally undesirable. Furthermore, the current contact force adjustment devices only allow for a rough and relatively imprecise adjustment of the contact force.

[0025] Using the proposed magnetic element, the contact pressure can now be influenced in a very targeted and sensitive manner. The magnetic element acts on the dosing element, which for this purpose must be made of a magnetic or ferromagnetic material, or at least comprise one element made of magnetic or ferromagnetic material. This effect can, in principle, be repulsive or attractive. In order to enable or support hydrodynamic dosing, it is advantageous if at least one magnetic element is designed such that the magnetic force counteracts the contact pressure of the contact pressure unit. In this case, the magnetic element relieves the contact pressure exerted by the dosing element on the moving surface to be coated, without any noticeable geometric change in the positioning or deflection of the dosing element.

[0026] A further advantage of this device is that the inclusion of magnetic elements makes it possible to influence the contact force without noticeably changing the geometry of the dosing element, such as blade deflection or the contact zone. In dosing blades, the magnetic field changes the stiffness of the blade, but hardly affects its deformation.

[0027] The effect of the magnetic element is - for an external observer - similar to a (virtual) increase in the viscosity of the application medium during hydrodynamic dosing of liquid or pasty films.

[0028] The proposed solution is also advantageous because it can be easily retrofitted into existing systems. The magnetic element simply needs to be added to the dosing element's holding fixture. This magnetic element can also be sensitively guided without any major difficulties using a precise positioning device. This allows the user to significantly expand the application spectrum of their coating devices at low cost. Since dismantling by removing the magnetic elements is also very quick and easy, the user does not incur any risk during the retrofit, which further increases the acceptance of the new device.

[0029] The magnetic element can be designed as an electromagnet or as a permanent magnet.

[0030] The distance between the magnetic element and the dosing element can be less than 20 mm, especially less than 10 mm, and especially less than 5 mm. Distances of 1 mm or less are also possible.

[0031] In advantageous embodiments, it can be provided that the magnetic force acting on the dosing element is controllable. In particular, it can also be provided that the effect of the magnetic force on the dosing element can be completely or largely deactivated.

[0032] When using suitable electromagnets, such control is very easily achieved by adjusting the current. However, the magnetic force can also be controlled when using permanent magnets. For example, the distance between the magnetic element and the dosing element can be adjusted.

[0033] In principle, a manually operated adjustment device is conceivable for such an adjustment. However, for such an adjustment of the distance, it is advantageous if at least one servomotor is provided to adjust the distance between the magnetic element and the dosing element. With such servomotors, in particular with linear servomotors, a very precise and sensitive adjustment of the distance can be achieved. A movement of the magnets in the pm range or in the 1 / 10 mm range relative to the magnetic or ferromagnetic part of the dosing element is possible here, whereby the magnetic force acting on the dosing element can be reduced or increased in very small steps. The relief of the dosing element by the magnetic force is therefore possible in very fine steps.

[0034] Such a highly sensitive adjustment of the contact force via the contact pressure element would not be possible with today's conventional contact pressure elements. The metering elements in modern systems such as paper machines can extend over 10 meters or more. To enable uniform control of the force on the metering element, it is advantageous if the magnetic element extends over the entire length of the metering element (in the cross-machine direction).

[0035] Such a long magnetic element can be implemented in various ways. For example, the magnetic element can be designed as a continuous magnetic strip. Alternatively, the magnetic element can be constructed from several individual magnets arranged side by side. The spacing of these individual magnets can be adapted to the type of dosing element and the materials used. The spacing between two adjacent magnets is often 10 mm or more, in particular 20 mm or more. When using magnetic dosing strips (composed of several magnet segments arranged in a row), the pitch (and thus the spacing between adjacent magnet segments) can be in the range of 50 mm to 100 mm, or in some cases, more than 100 mm.

[0036] It is particularly advantageous if means are provided for profiling the magnetic force over the length of the dosing element and thus in the cross-machine direction when the device is installed. This enables very precise profiling of the active contact pressure on the running surface. These means can be implemented, for example, by using several individual magnets and equipping several, in particular all, of these magnets with a servomotor to adjust the distance between the magnets and the dosing element. Alternatively, a plurality of electromagnets can be used, in which the magnetic force can be changed independently of one another, for example by varying the current strength. Alternatively, manual adjustment via a spindle with fine spindle pitch is also possible.

[0037] In preferred embodiments, the magnetic force per cm can be between 0.01 g / cm and 10 kg / cm, preferably between 0.1 g / cm and 10 kg / cm, in particular between 0.05 g / cm and 5 kg / cm, particularly preferably between 0.5 g / cm and 3 kg / cm. It is particularly advantageous if the magnetic force on the metering element can be varied within the specified ranges—for example, by varying the distance between the magnetic element and the metering element.

[0038] To enable stable operation of the device, it is advantageous if the magnetic or ferromagnetic material used does not lose its ferromagnetic properties, even if an elevated temperature prevails at the place of use - for example due to an operating error or extraordinary production situations. In preferred embodiments, it can therefore be provided that the Curie temperature (Tc) of the magnetic or ferromagnetic material is at least 80°C, in particular at least 100°C. This is particularly advantageous if a starch solution is used as the application medium. This must be heated before application. Depending on the starch used (wheat, potato, corn, or rye starch), the temperature required for gelatinization varies. As a consequence, the heating of the dosing element due to contact with the starch can also vary.However, at a Curie temperature of over 80°C, and especially over 100°C, the dosing element can be used for all common types of starch without the risk of a loss of the magnetic properties of the magnetic or ferromagnetic material, and thus a disruption of the function of the dosing device.

[0039] In addition to iron (Tc=759°C) and nickel (Tc=353°C), CrO2 (Tc=116°C), for example, also exhibits a corresponding Curie temperature. Neodymium magnets can be set to Curie temperatures of over 100°C. Therefore, these materials are particularly suitable for use as magnetic or ferromagnetic materials for the dosing element.

[0040] Neodymium magnets are particularly suitable because they can provide high magnetic forces with small material volume, which enables a compact design of the application device.

[0041] With regard to the method, the object is achieved by a method for dosing or leveling a liquid or pasty application medium onto a moving surface, wherein the application medium is first applied to the moving surface and then dosed or leveled by means of a device, wherein the device is designed according to one aspect of the invention.

[0042] The moving surface can either be a material web to be coated, for example, a paper, packaging, or cardboard web ("direct coating"). Alternatively, the moving surface can also be the surface of a transfer element, in particular a transfer roller, from which the application medium is subsequently transferred to the material web.

[0043] In advantageous embodiments of the method, it can be provided that the application medium has a “high-shear viscosity” of less than 80 mPas, and / or a film with a film thickness between 5 pm and 100 pm, in particular between 5 pm and 50 pm, is dosed.

[0044] A particularly preferred embodiment is the use of a starch solution as the application medium.

[0045] Alternatively, low-viscosity application liquids can be used as an application medium for the production of barrier layers (water-vapor barriers, grease barriers, oxygen barriers, bacterial barriers, light barriers, etc.).

[0046] The advantages of a device according to one aspect of the invention are particularly evident when such a device is used for metering or leveling a liquid or pasty application medium onto a moving surface, wherein the moving surface is the surface of a roller, and wherein this surface has a hardness between 60-100 shoreD, preferably between 80-95 shoreD. Such rollers are increasingly used in the field of starch application. In so-called hard-nip sizing, a starch solution is metered onto two hard rollers in a film press, which then transfer the starch to a fibrous web in a transfer nip formed by the two rollers.

[0047] For such hard surfaces, the use of contact dispensing systems is undesirable due to the significant wear. Therefore, contactless, hydrodynamic dispensing offers particularly significant advantages. The devices proposed here allow a significantly broader range of applications than previously possible with hydrodynamic dispensing. This significantly expands the application range of film presses in the field of hard-nip sizing.

[0048] When metering onto the surface of a rotating roller, especially a hard roller with a surface hardness between 60 and 100 shore D, it is very advantageous if the runout is very low, particularly in the range of < 40 pm. This is very advantageous for stable hydrodynamic metering of a uniform film thickness.

[0049] When metered onto a rotating roller, the application medium can be transferred from the roller surface to a fibrous web, such as a paper, cardboard, or packaging web, using a transfer nip. This is referred to as indirect application.

[0050] Alternatively, the application medium can be metered directly onto a fibrous web as a moving surface. When applying this directly onto the surface of a fibrous web, the web can be guided on a roller, particularly in the application area.

[0051] In both direct and indirect application, the fibrous web can have a basis weight between 20 and 400 g / m 2 , preferably between 40 - 120 g / m 2 have.

[0052] The moving surface can have a speed of more than 1000 m / min, in particular more than 1500 m / min, preferably 1800 m / min or more. The invention is explained below with reference to figures. The invention is not limited to these embodiments. The figures show in detail:

[0053] Figure 1 shows a dosing and leveling device according to one aspect of the present invention.

[0054] Figure 2 shows a device for dosing and leveling according to a further aspect of the present invention

[0055] Figures 3a and 3b schematically show an aspect of the mode of operation in a variant of the present invention.

[0056] Figures 4a and 4b show a device for dosing and leveling according to further aspects of the present invention

[0057] Figure 5 schematically shows an aspect of the mode of operation in a further variant of the present invention.

[0058] Figure 1 shows a device according to one aspect of the invention. In this embodiment, a dosing blade 1 is used as the dosing element 1. This dosing blade 1 is pressed against the moving surface 5 by means of a pressing unit 2. The pressing unit 2 is implemented here as a mechanical pressing unit 2, with the pressing being controlled by means of an adjusting screw. A plurality of such adjusting screws are arranged along the length of the dosing element 1 to enable profiling of the contact force. Alternatively, other implementations of the pressing unit 2 are also possible and in use.

[0059] An application medium 4 is applied to the moving surface 5 by means of an application unit (not explicitly shown). The dosing blade 1 is in contact with the application medium 4 in a contact zone 6. If the application medium 4 is applied in excess, the excess application medium 4 can be removed by the dosing blade 1, so that only the desired amount remains dosed onto the moving surface 5. Alternatively or additionally, the blade 1 can also equalize the application medium 4 over the length of the dosing element 1.

[0060] A magnetic element 3 is also provided in the device. This magnetic element 3 is arranged such that the magnetic force between the pressing unit 2 and the contact zone 6—in Figure 1 directly in the area of ​​the contact zone 6—acts on the dosing element 1. In the embodiment shown in Figure 1, the entire dosing element 1 in the form of a dosing blade 1 is made of a magnetic or ferromagnetic material. Alternatively or additionally, it can also be provided that an element made of a magnetic or ferromagnetic material is attached to the dosing element 1 in the area of ​​the contact zone 6.

[0061] The magnetic element 3 can be implemented using electromagnets or permanent magnets. A plurality of such magnets can be arranged next to one another along the length of the dosing element 1 to enable profiling. Alternatively, the magnetic element 3 can also be designed, for example, as a continuous magnetic strip 3.

[0062] Neodymium magnets are particularly suitable because they can provide high magnetic forces with a small material volume, which enables a compact design of the application device.

[0063] Advantageously, the magnetic force acting on the dosing element 1 is controllable. In the embodiment shown in Figure 1, this is achieved by adjusting the distance between the magnetic element 3 and the dosing element 1. This can be achieved, for example, using suitable servomotors, e.g., linear servomotors.

[0064] Figure 2 shows an alternative implementation of a device according to aspects of the present invention. In contrast to Figure 1, the dosing element 1 is not a dosing bell. Instead, dosing is carried out by means of a doctor rod 8 which is rotatably mounted in a holder. Figure 2 also shows an implementation of hydrodynamic dosing. For this purpose, the doctor rod 8 is advantageously designed as a smooth doctor rod 8. This contacts the application medium 4 in a contact zone 6, but not directly the moving surface 5 during hydrodynamic application. The holders for the doctor rod 8 are often made of a non-magnetic plastic material. In order to nevertheless enable the effect of the magnetic force of the magnetic element 3 on the dosing element 1, an additional element made of magnetic or ferromagnetic material 7 is provided here as an example, which is attached to the dosing element 1 in particular in the region of the contact zone.The same applies to the design of the pressing unit 2 and the magnetic element 3 as for the corresponding elements in Figure 1.

[0065] Figures 3a and 3b are intended to illustrate, once again by way of example, an aspect of the mode of operation of an embodiment of the present invention. Figure 3a shows the force situation in the contact zone 6. The contact force F-blade of a dosing blade 1 acts in the direction of the moving surface 5, while the hydrodynamic force F-hydrodyn of the application medium acts in the opposite direction. This often results in a very low film thickness—for example, with application media 4 with a low "high-shear viscosity"—because the resulting force AF in the direction of the blade force F-blade exceeds the hydrodynamic force due to the additionally low speed of the moving surface 5.Thus, this resulting force AF will be directed in the direction of the running surface 5 and will reduce the film thickness until an equilibrium is reached. As a result, the desired floating of the metering element 1 (“aquaplaning”) does not occur and the metering element 1 can even touch the running surface 5 because no “lubricating film” is formed.

[0066] In devices according to aspects of the present invention, as shown in Figure 3b, a further force component is added: the magnetic force F-magnet. This acts in the same direction as the hydrodynamic force F-hydrodyn. The magnetic force F-magnet can now advantageously be adjusted so that the resulting force AF is no longer directed in the direction of the blade force F-blade, but rather in the direction of the hydrodynamic force F-hydrodyn. By adjusting the magnetic force F-magnet, the resulting force AF can be adjusted very precisely in embodiments according to aspects of the invention, for example to achieve a desired film thickness despite low viscosity of the application medium 4 or low speed of the moving surface 5.

[0067] Figures 4a and 4b show further possible implementations of a device according to aspects of the present invention. The device in Figure 4a largely corresponds to the device in Figure 2. Only the element made of magnetic or ferromagnetic material 7 has been replaced by an additional magnetic element 3a. The two magnetic elements 3, 3a are arranged relative to one another in such a way that they attract one another. Thus, the mode of operation of this embodiment is essentially analogous to the embodiment in Figure 2. However, the additional magnetic element 3a increases the effective magnetic force compared to the element made of magnetic or ferromagnetic material 7.

[0068] The device in Figure 4b also replaces the element made of magnetic or ferromagnetic material 7 with another magnetic element 3a. In contrast to Figure 4a, the magnetic elements 3, 3a in Figure 4b are arranged in such a way that the magnetic elements repel each other.

[0069] In the embodiment shown in Figure 4a, the dosing element 1 is pressed toward the moving surface 5 by a pressing unit 2. The attractive effect of the magnetic elements 3, 3a counteracts this blade force and relieves the load on the dosing element 1. In these embodiments, the magnetic force acts in the direction of the hydrodynamic force, while the blade force acts against the hydrodynamic force.

[0070] In designs such as those shown in Figure 4b, the magnetic force acts counter to the hydrodynamic force. For this purpose, the dosing unit 1 is designed so that the blade force acts in the direction of the hydrodynamic force. The dosing device 1 has a blade or spring part designed to push the dosing device 1 away from the moving surface 5. The function of the pressing unit 2 is performed by the repelling magnetic elements 3, 3a.

[0071] Figure 5 schematically shows the mode of operation of an embodiment of the invention shown in Figure 4b. Here, too, the magnetic force F-magnet acts against the blade force F-blade. Here, too, the magnetic force F-magnet can be adjusted very precisely, so that the resulting force AF from F-magnet on the one hand and F-blade and hydrodynamic force F-hydrodyn on the other hand has the desired value.

[0072] 1, 2 or 4a, the attractive magnetic force F-magnet serves exclusively to adjust the resulting force AF. In the versions with repulsive magnetic elements 3, 3a, the magnetic force F-magnet is essential for the functioning of the dosing device. The repulsive magnets 3, 3a here take on the function of the pressing unit 2. By changing the position of the magnet 3 relative to the position of the repulsive magnet 3a, the pressing force of the dosing element 1 can be regulated. A pre-tensioned or bent elastically resilient blade or a pre-tensioned elastically resilient holder of the metering rod can be influenced and sensitively regulated by changing the repulsive magnetic force F-magnet. In this respect, such a design is very advantageous because the dosing device requires fewer mechanical parts and is therefore simpler and cheaper to manufacture.

[0073] In the case of designs with attractive magnets or attractive magnets and ferromagnetic squeegee elements, it can generally happen that magnetic element 3 and squeegee element 7 attract each other too strongly, resulting in a sudden jump and adhesion of the ferromagnetic squeegee element to the magnet. This situation is undesirable.

[0074] This can occur if the distance between the magnetic element 3 and the ferromagnetic or magnetic squeegee element 7 falls below a certain minimum limit. This behavior cannot occur in designs with repulsive magnets, since the repulsive force increases as the distance between the magnets 3, 3a decreases.

[0075] List of reference symbols

[0076] 1 dosing element

[0077] 2 Pressing unit 3 Magnetic element

[0078] 3a Magnetic element

[0079] 4 Order medium

[0080] 5 running surface

[0081] 6 Contact zone 7 Element made of magnetic or ferromagnetic material

[0082] 8 doctor rod

Claims

Patent claims 1. Device for metering or leveling a liquid or pasty application medium (4) onto a moving surface (5) comprising a metering element (1 ) for contacting the application medium (4) in a contact zone (6), and a pressure unit (2) for pressing the metering element (1 ) against the moving surface (5), characterized in that the metering element (1 ) consists entirely or partially of a magnetic or ferromagnetic material, and that the device further comprises at least one magnetic element (3) which acts repulsively or attractively on the metering element (1 ).

2. Device according to claim 1 characterized in that the magnetic element (3) is arranged such that the magnetic force acts on the metering element (1) between the pressure unit (2) and the contact zone (6), in particular in the area of ​​the contact zone (6), wherein the at least one magnetic element (3) is designed such that the magnetic force opposes the pressure force of the pressure unit (2) and the magnetic force acts in particular attractively on the metering element (1).

3. Device according to claim 1, characterized in that the magnetic force acts repulsively on the metering element (1) and wholly or partially takes over the function of the pressing unit (2).

4. Device according to claim 3, characterized in that the metering element has retrieval means which counteract the repulsive magnetic force.

5. Device according to one of the preceding claims, characterized in that the metering element (1 ) comprises a metering blade (1 ) or a squeegee rod (8). A device according to any of the preceding claims, characterized in that the magnetic force acting on the metering element (1) is controllable. A device according to claim 6, characterized in that the distance of the magnetic element (3) to the metering element (1) is adjustable. A device according to claim 7, characterized in that at least one actuator, in particular a linear actuator, is provided to adjust the distance of the magnetic element (1) to the metering element (1). A device according to any of the preceding claims, characterized in that the distance of the magnetic element (3) from the metering element (1) is less than 20 mm, in particular less than 5 mm, preferably 1 mm or less. A device according to any of the preceding claims, characterized in that the magnetic element (3) extends over the entire length of the metering element (1) in the transverse direction of the machine.A device according to any of the preceding claims, characterized in that means for profiling the magnetic force over the length of the metering element (1) are provided. A device according to any of the preceding claims, characterized in that the magnetic force per cm is between 0.01 g / cm and 10 kg / cm, in particular between 0.05 g / cm and 5 kg / cm, and most preferably between 0.5 g / cm and 3 kg / cm. A device according to any of the preceding claims, characterized in that the Curie temperature of the magnetic or ferromagnetic material is at least 80°C, in particular at least 100°C. A method for metering or leveling a liquid or pasty application medium (4) onto a moving surface (5), wherein the application medium (4) is first applied to the moving surface (5) and subsequently metered or leveled by means of a device, characterized in that the device is designed according to one of the preceding claims. A method according to claim 14, characterized in that the application medium (4) has a high-shear viscosity of less than 80 mPas, and / or a film with a film thickness between 5 pm and 100 pm, in particular between 5 pm and 50 pm, is metered. Use of a device according to one of claims 1 to 13 for metering or leveling a liquid or pasty application medium (4) onto a moving surface (5), wherein the moving surface (5) is the surface (5) of a roller, and wherein this surface (5) has a hardness between 60 and 100 Shore D, preferably between 80 and 95 Shore D.

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