Method for coating a web-shaped substrate and device for carrying out the method

Abstract

Method for coating a web-shaped substrate (01) with a heat-curable pasty medium (02) with the following method steps: - unwinding the web-shaped substrate (01) from a substrate supply roll (04) in an unwinding device (06), - applying a layer of the pasty medium (02) with a predetermined layer thickness to the web-shaped substrate (01) in an application device (07), - passing the web-shaped substrate (01) with the layer of the pasty medium (02) applied thereto through an NIR drying unit (08), in which the layer of the pasty medium (02) is irradiated by at least one NIR radiator (10) with infrared radiation in the near infrared range, - subsequently passing the web-shaped substrate (01) with the pre-dried layer of the pasty medium (02) applied thereto through a hot-air drying unit (12, 12a, 12b), in which the layer of pasty medium (02) is exposed to heated air of a predetermined temperature, and - Winding up the web-shaped substrate (01) with the layer of the dried pasty medium (02) applied thereto to form a roll (14) in a winding device (16), wherein a first detection device (20) for detecting the layer thickness of the first layer of the pasty medium (02) is arranged upstream of the NIR drying unit (08) as viewed in the web travel direction, and wherein a second detection device (22) is arranged downstream of the hot-air drying unit (12) as viewed in the web travel direction, by means of which the layer thickness of the dried layer of the applied pasty medium (02) is detected, and wherein the radiation power emitted by the at least one NIR radiator (10) is controlled or regulated as a function of the layer thickness detected by the first detection device (20) and second detection device (22).

Description

[0001] The invention relates to a method for coating a web-shaped substrate and to a device for carrying out the method according to the features of claims 1 and 11.

[0002] In the field of coating web-shaped substrates, such as metal strips with paints or varnishes, it is known to unwind these from a substrate supply roll in an unwinding device, apply the coating material, for example the paint, via an application device, and then convey the web-shaped substrate with the applied coating material through a radiation dryer, where it is exposed to infrared radiation. After passing through the radiation dryer, the heated substrate is fed to a downstream cooling device, where the coated substrate is cooled before being wound up again into a roll in a downstream winding device.

[0003] Such a previously described method and an associated device for coating metal sheets with paint are known, for example, from EP 1 893 349 B1. Due to their robustness, the only important factor in the described coating of metal sheets is to apply the highest possible thermal energy to the previously applied paint in order to dry it. This, in turn, necessitates the cooling of the sheet substrate, which is heated considerably during the drying process in the IR dryer, in a downstream cooling device, which involves considerable energy consumption.

[0004] Due to the strong heating of the metal sheets in the IR dryer and the immediate subsequent extreme cooling of the material, the device described in EP 1 893 349 B1 is not suitable for the production of mechanically and chemically very sensitive coatings on thermally and mechanically sensitive web-shaped substrates, such as the application of solids dissolved in solvents such as 1-N-methyl-2-pyrrolidone, in particular metal oxides, graphites, carbon blacks, organic polymers, etc., on web-shaped copper, aluminum or nickel, the latter of which can also be applied, for example, to polymer films (PET-siliconized) that serve as carrier films.

[0005] The substrates and coating materials described above are used, for example, in the production of lithium-based battery cells, wherein the coating material contains a water-based solvent to provide the anode on the web-shaped substrate, and the cathode contains the aforementioned 1-N-methyl-2-pyrrolidone.

[0006] DE 10 2010 032 786 A1 discloses a coating method for metal strips, wherein a primer is dried by heat transfer, wherein the primer applied to the substrate is pre-dried by means of infrared radiation in a first drying step, wherein a topcoat layer is subsequently applied to the pre-dried primer and the pre-dried primer is cured together with the topcoat layer in a second drying step.

[0007] Accordingly, the object of the invention is to provide a method and a device with which the aforementioned solids can be applied to web-shaped metal substrates, in particular made of copper, aluminum or nickel, with a high quality and homogeneity.

[0008] The invention is based on the object of providing a method for coating a web-shaped substrate and a device for carrying out the method.

[0009] The object is achieved according to the invention by the features of claims 1 and 11.

[0010] Further features of the invention are contained in the subclaims.

[0011] According to the invention, a method for coating a web-shaped substrate with a heat-curable pasty medium comprises the following process steps: - Unwinding the web-shaped substrate from a substrate supply roll in an unwinding device, - Applying a layer of the pasty medium with a predetermined layer thickness to the web-shaped substrate in an application device, - passing the web-shaped substrate with the layer of pasty medium applied thereon through an NIR drying unit in which the layer of pasty medium is irradiated by at least one NIR radiator with infrared radiation in the near infrared range, - subsequently passing the web-shaped substrate with the pre-dried layer of the pasty medium applied thereto through a hot-air drying unit in which the layer of pasty medium is exposed to heated air of a predetermined temperature, and - Winding up the web-shaped substrate with the layer of the dried pasty medium applied thereon to form a roll in a winding device.

[0012] The web-shaped substrate is preferably a copper web or an aluminum web or a nickel web or a polymer web, ie a copper, aluminum, nickel, or polymer foil, which can have a thickness in the range of substrate thickness 5 - 150 µm and is rolled up into a roll as a roll.

[0013] The process has the advantage that multi-layer coatings can be applied to the substrate without the need for additional equipment. For example, in a first step, a primer is applied, followed by the application of a pasty coating material, also known as a "slurry." After application, drying, and winding, the web-like substrate is moved backward in the system. Then, in a subsequent second process step, the top side of the dried substrate, coated with the primer, for example, is coated with a second coating. This second coating can be the same or a different coating material, which can be applied in a different thickness if desired.

[0014] Depending on the desired layer structure, thickness and rheological properties of the pastes, coating materials other than those mentioned above can also be used.

[0015] Irrespective of this, the use of the method and the device for carrying it out makes it possible to coat the web-shaped substrate on both sides with one or more layers.

[0016] For this purpose, the single-sided coated roll is removed from the take-up device, transported back to the unwinder, and inserted into it so that the previously applied coating is on the underside of the web. Subsequently, the coating process on the top side of the web-shaped substrate takes place in the manner described above, in particular by doctoring the additional coating material onto the uncoated or coated top side of the web, which is moved at a preset speed of, for example, 0.1 - 5 m / min during the coating process.

[0017] In the preferred embodiment of the method, the application device for the pasty medium comprises a support roller over which the web-shaped substrate is guided during application of the pasty medium. This ensures that the upper side of the web-shaped substrate to be coated is always in a well-defined position during application of the pasty coating medium.

[0018] As the applicant has discovered, qualitatively optimal coating results with a highly homogeneous layer thickness of the coating material can be achieved by using a doctor blade, in particular a known Coma doctor blade, pointed doctor blade, or shoe doctor blade, which cooperates with the support roller, i.e., is positioned against it. Alternatively, however, the application device can also comprise a slot die extending over at least a portion of the width of the web-shaped substrate 01.

[0019] The various pointed, shoe, and coma doctor blades are preferably attached to a doctor blade carrier in a fixed changeover position. The doctor blade is then manually aligned to the support roller, for example, using two motor-adjustable feed spindles, for which a predefined final gauge can be used. The actual value of the doctor blade gap is then "zeroed," thereby calibrating the system to the set value. The actual position of the doctor blade adjustment system is preferably detected by a corresponding sensor. The gap of the doctor blade can be adjusted accordingly, allowing coatings of variable thicknesses to be produced.

[0020] During coating, the doctor blade gap can be changed manually by 1 µm in steps, preferably via motorized adjustment, using an input device such as a touch panel.

[0021] In the preferred embodiment of the invention, the layer thickness of the pasty medium applied to the web-shaped substrate is variable, and the radiation intensity of the NIR emitter in the NIR drying unit is selected depending on the layer thickness of the pasty medium on the web-shaped substrate such that the penetration depth of the electromagnetic radiation of the NIR emitter corresponds to the layer thickness of the pasty medium. This results in the advantage that only the pasty coating material is heated by the electromagnetic radiation in the near infrared range, whereas the substrate to be coated is not exposed to the radiation itself and is heated directly.

[0022] According to a further concept underlying the invention, the hot-air drying unit comprises a first hot-air drying zone and a second hot-air drying zone arranged downstream of this zone in the direction of web travel during the coating process. The use of two hot-air drying zones arranged one after the other in the direction of web travel opens up the possibility of adapting the drying performance within wide limits depending on the thickness of the applied coating layer and the desired residence time in the hot-air drying unit, which depends on the coating material.

[0023] In the method, a first detection device for detecting the layer thickness of the first layer of the pasty medium is arranged upstream of the NIR drying unit 08, viewed in the web travel direction, and the radiation output emitted by the at least one NIR radiator 10 is controlled or regulated as a function of the detected layer thickness. This ensures that the penetration depth of the NIR radiation can be optimized, even in the case of slight thickness fluctuations of the coating, to such an extent that it heats exclusively the coating material to be dried and not the web-shaped substrate. Furthermore, this embodiment of the invention opens up the possibility of optimally drying coatings with a variable thickness profile without undesired excessive heating of the substrate or the coating material in the final product not being completely dried.

[0024] In the last-described embodiment of the invention, it is further advantageous if a second detection device for detecting the layer thickness of the dried layer of the pasty medium / coating material, viewed in the web travel direction, is arranged downstream of the hot-air drying unit, by means of which the layer thickness of the dried layer can be detected. This opens up the possibility of also controlling and regulating the temperature of the hot air in the hot-air drying unit as a function of the layer thickness of the pasty medium detected by the second detection device and / or as a function of the difference between the layer thickness of the pasty medium detected by the first detection device and the layer thickness of the pasty medium on the web-shaped substrate detected by the second detection device, in order to further increase the precision of the coating process and correspondingly improve the quality of the coated end product.

[0025] According to a further concept underlying the invention, it can be provided that a flat sample section can be separated from the dried web-shaped substrate in a sampling device arranged downstream of the hot-air drying unit and upstream of the winding device. This can then be removed from the sampling device, in particular by hand. This opens up the possibility of monitoring the quality of the final product at any time during the setup of the device according to the invention in the event of changes in operating parameters such as the power of the NIR radiators or the temperature or volume flow of the hot air supplied in the hot-air drying zones.

[0026] In the preferred embodiment of the invention, the substrate supply roll is rotated by an associated drive motor through a predetermined angle of rotation opposite to the withdrawal direction of the web-shaped substrate in order to remove a sample.

[0027] The web-shaped substrate with the layer of dried pasty medium applied thereon is moved over a delivery table or cutting table arranged in the sampling device, on which the sample section is cut out of the web-shaped substrate by means of one or more roller cutting knives.

[0028] For this purpose, the web-shaped substrate, with the dried coating applied thereon, is advantageously clamped in a coated area upstream and downstream of the cutting table. The cutting device, e.g., a rotary cutter, then preferably automatically separates the flat sample section. The separated individual sheet is then removed manually after release. The web is then moved further in the reverse direction by, e.g., 500 mm to separate the next flat sample section. During the return travel of the web-shaped substrate, it is preferably supported by a conveyor belt moved over the delivery table.

[0029] An embodiment of the invention is shown in the drawing and is described in more detail below.

[0030] They show: Fig. 1 is a schematic side view of a preferred device for carrying out the method; Fig. 2 a schematic plan view of the device of Fig. 1.

[0031] As the representation of Fig. 1 and Fig. 2, a device 01 for carrying out the method comprises an unwinding device 06 for unwinding web-shaped substrate 01, which is provided in the form of a substrate supply roll 04, which can be driven by a drive motor 04a both in the web running direction and in the opposite direction thereto.

[0032] The device 01 further comprises an application device 07 for applying a layer of the pasty medium 02 with a predetermined layer thickness onto the web-shaped substrate 01.

[0033] As in Fig. 1, the application device for the pasty medium has a support roller 07a, which interacts with a doctor blade 07b, in particular a Coma doctor blade, pointed doctor blade, or shoe doctor blade, or a slot die, which extends over at least a partial section of the width of the web-shaped substrate 01. The support roller 07a, over which the web-shaped substrate 01 is guided after unwinding from the supply roll 04, is preferably driven by its own controlled drive motor 07c. This ensures that the layer thickness of the applied pasty medium 02 does not change disadvantageously as a result of web tension fluctuations.

[0034] Downstream of the application device 07 in the web travel direction is an NIR drying unit 08, in which at least one NIR radiator 10 is arranged, which exposes the web-shaped substrate 01 to electromagnetic radiation whose wavelength lies in the near infrared range on the side to which the pasty medium 02 was applied, or alternatively on both sides. The NIR radiator is preferably a radiator with integrated warm air ventilation, wherein for a more uniform introduction of the radiant energy into the substrate 01, several radiator arrangements with, for example, 3 or more NIR radiators are provided on each side of the web-shaped substrate 01. These can preferably have up to 12 power control values each spaced 30 mm apart, whereby a virtually variable temperature profile can be set at the top and bottom.

[0035] The NIR drying unit 08 is followed in the web travel direction by a hot air drying unit 12, which is also referred to below as a convection dryer, and in which the layer of the pasty medium 02 irradiated with infrared radiation in the near infrared range is exposed to heated air of a predetermined temperature, which is preferably between 140 and 150°C at most.

[0036] As the representations of the Fig. 1 and Fig. 2, the hot air drying unit 12 in the preferred embodiment of the invention has a first hot air drying zone 12a and a second hot air drying zone 12b arranged downstream of this in the running direction of the web-shaped substrate 01, through which the substrate 01 passes one after the other after the application of the pasty coating material 02. In order to achieve particularly efficient operation of the device, it can further be provided that the dryer exhaust air of the NIR dryer unit 08 is passed via the hot air drying unit 12 as supply air when operated jointly with the hot air drying unit 12.

[0037] As the Fig. 1 and Fig. 2 further show, a first detection device 20 for detecting the layer thickness of the first layer of the pasty medium 02 is arranged upstream of the NIR drying unit 08 as viewed in the web travel direction, and simultaneously or alternatively a second detection device 22 is arranged downstream of the hot air drying unit 12 as viewed in the web travel direction, by means of which the layer thickness of the dried layer of the applied pasty medium 02 can be detected.

[0038] In order to be able to apply different coating materials in different thicknesses to the web-shaped substrate 01, the distance between the wiping edge of the doctor blade 07b facing the substrate 01 and the support roller 07a can be varied, preferably by motor, via threaded spindles (not shown in detail) that are driven by associated motors. The distance can advantageously be controlled or regulated by a control device (not shown in detail) depending on the layer thickness detected by the first detection device 20 and / or second detection device 22.

[0039] In the same way, the radiation power emitted by the at least one NIR radiator 10 can be controlled as a function of the layer thickness detected by the first detection device 20 and / or second detection device 22.

[0040] In order to be able to specifically change the temperature profile in the layer of applied coating material 02 and the substrate 01 in the holding zone and to adapt it to the respective coating material, the temperature of the hot air in the hot air drying unit 12 is controlled or regulated as a function of the layer thickness of the pasty medium 02 detected by the second detection device 22 and / or as a function of the difference between the layer thickness detected by the first detection device 20 and the layer thickness of the dried pasty medium 02 on the web-shaped substrate 01 detected by the second detection device 22.

[0041] However, the dryer temperature can also be set manually based on existing experience.

[0042] The control and regulation of the previously described machine components, manipulated variables and parameters is preferably also carried out via the previously mentioned control device, which is not shown in detail.

[0043] After the web-shaped substrate 01 with the dried layer of coating material has emerged from the second hot-air drying zone 12b, it is fed to a winding device 16, in which the web-shaped substrate 01 with the layer of dried pasty medium 02 applied thereto is wound into a roll 14. For this purpose, the roll 14 is driven by its own drive motor 14a.

[0044] As the representation of Fig. 1 and Fig. 2 can still be removed, a sampling device 18 is arranged upstream of the winding device 16, by means of which a flat sample section 01a can be separated from the dried web-shaped substrate 01.

[0045] In order to remove such a flat sample section 01a from the dried substrate 01, the substrate supply roll 04 is rotated by the associated drive motor 04a in the opposite direction to the withdrawal direction of the web-shaped substrate 01. The web-shaped substrate 01, with the layer of dried pasty medium 02 applied thereto, is moved over a delivery table 18a arranged in the sample removal device 18, on which the sample section 01a is cut out of the web-shaped substrate 01 by means of one or more roller cutting knives 18b.

[0046] In the preferred, in Fig. 1 and Fig. In the embodiment of the invention shown in Figure 2, the web-shaped substrate is clamped by running or holding rollers 18c and 18d on associated pulling rollers 18e and 18f, and a first sample section 01a is cut out with the rotary cutting knives 18b, which is then preferably removed manually.

[0047] The pull roller 18e at the inlet of the delivery table 18 and the pull roller 18f at the outlet of the delivery table 18a are driven by associated drive motors 18g and 18h, as shown in Fig. 2 is indicated.

[0048] Subsequently, the web-shaped substrate 01 with the dried pasty medium 02 applied thereon is moved by a certain length onto the delivery table 18a by means of the winding device 16 and the pulling roller 18f with the roller 18d engaged, and the next section is carried out with the rotary cutting knife 18b.

[0049] As the representation of the Fig. 1 can be removed further, the web-shaped substrate 01 is advantageously supported during the return movement by an endlessly circulating conveyor belt 25, which runs along the upper side of the delivery table 18a and supports the substrate from below.

[0050] During the coating process and preferably also during sampling, the lateral position of the web-shaped substrate 01 is monitored and, if necessary, corrected by a known web edge controller 23 with web edge and layer edge sensor arranged downstream of the unwinding device 06 and a web edge controller 24 with web edge sensor arranged immediately upstream of the winding device 16. List of reference symbols 01 web-shaped substrate 01a Sample section 02 pasty medium 03 - 04 Substrate supply roll 04a Drive motor for supply roll 05 - 06 Unwinding device 07 Application device for the pasty medium 07a Support roller 07b Squeegee 07c Drive motor for support roller 08 NIR drying unit 09 - 10 NIR emitters 11 - 12 Hot air drying unit 12a first hot air drying zone 12b second hot air drying zone 13 - 14 wraps 14a Drive motor winding 15 - 16 winding device 17 - 18 Sampling device 18a Display table with belt 18b Roller cutting blade 18c holding rollers inlet delivery table 18d Holding and running rollers outlet display table 18e Infeed roller delivery table 18f discharge roller delivery table 18g drive motor infeed roller 18h drive motor discharge roller 19 - 20 first detection device for detecting the layer thickness 21 - 22 second detection device for detecting the layer thickness of the dried layer of the pasty medium 23 web edge controllers 24 web edge controllers 25 conveyor belt

Claims

[1] Method for coating a web-shaped substrate (01) with a heat-curable pasty medium (02) with the following method steps: - unwinding the web-shaped substrate (01) from a substrate supply roll (04) in an unwinding device (06), - applying a layer of the pasty medium (02) with a predetermined layer thickness to the web-shaped substrate (01) in an application device (07), - passing the web-shaped substrate (01) with the layer of the pasty medium (02) applied thereon through an NIR drying unit (08), in which the layer of the pasty medium (02) is irradiated by at least one NIR radiator (10) with infrared radiation in the near infrared range, - subsequently passing the web-shaped substrate (01) with the pre-dried layer of the pasty medium (02) applied thereto through a hot-air drying unit (12, 12a, 12b), in which the layer of pasty medium (02) is exposed to heated air of a predetermined temperature, and - Winding up the web-shaped substrate (01) with the layer of the dried pasty medium (02) applied thereto to form a roll (14) in a winding device (16), wherein a first detection device (20) for detecting the layer thickness of the first layer of the pasty medium (02) is arranged upstream of the NIR drying unit (08) as viewed in the web travel direction, and wherein a second detection device (22) is arranged downstream of the hot-air drying unit (12) as viewed in the web travel direction, by means of which the layer thickness of the dried layer of the applied pasty medium (02) is detected, and wherein the radiation power emitted by the at least one NIR radiator (10) is controlled or regulated as a function of the layer thickness detected by the first detection device (20) and second detection device (22). [2] Method according to claim 1, characterized bythat the application device (07) for the pasty medium (01) comprises a support roller (07a) over which the web-shaped substrate (01) is guided during the application of the pasty medium (02). [3] Method according to claim 2, characterized by that the application device (07) comprises a doctor blade (07b) interacting with the support roller (07a), in particular a comma doctor blade or pointed doctor blade or shoe doctor blade, or a slot die, which extends over at least a partial section of the width of the web-shaped substrate (01). [4] Method according to one of the preceding claims, characterized bythat the layer thickness of the layer of the pasty medium (02) applied to the web-shaped substrate (01) is variable, and that the radiation intensity of the NIR radiator (10) in the NIR drying unit (08) is selected as a function of the layer thickness of the pasty medium (02) on the web-shaped substrate (01), such that the penetration depth of the electromagnetic radiation of the NIR radiator (10) corresponds to the layer thickness of the layer of the pasty medium (02). [5] Method according to one of the preceding claims, characterized by that the hot air drying unit (12) has a first hot air drying zone (12a) and a second hot air drying zone (12b) arranged downstream of this in the web running direction of the web-shaped substrate (01). [6] Method according to claim 1, characterized bythat the temperature of the hot air in the hot air drying unit (12) is controlled or regulated as a function of the layer thickness of the pasty medium (02) detected by the second detection device (22) and / or as a function of the difference between the layer thickness detected by the first detection device (20) and the layer thickness of the dried pasty medium (02) on the web-shaped substrate (01) detected by the second detection device (22). [7] Method according to one of claims 1 or 6, characterized by that the distance between the scraper edge of the doctor blade (07b) facing the substrate (01) and the support roller (07a) can be changed by a motor, and that the distance between the scraper edge and the support roller (07a) is controlled or regulated as a function of the layer thickness detected by the first detection device (20) and / or second detection device. [8] Method according to one of the preceding claims, characterized by that a flat sample section (01a) can be separated from the dried web-shaped substrate (01) in a sampling device (18) arranged downstream of the hot-air drying unit (12) and upstream of the winding device (16). [9] Method according to claim 8, characterized by that the substrate supply roll (04) is rotatable by an associated drive motor (04a) opposite to the withdrawal direction of the web-shaped substrate (01), and that the supply roll (04) is rotated by a predetermined angle of rotation opposite to the withdrawal direction before the sample section (01a) is separated out. [10] Method according to claim 8 or 9, characterized bythat the web-shaped substrate (01) with the layer of the dried pasty medium (02) applied thereto is moved over a delivery table (18a) arranged in the sampling device (18), on which delivery table the sample section (01a) is cut out of the web-shaped substrate (01) by means of one or more roller cutting knives (18b). [11] Device for carrying out the method according to one of the preceding claims, comprising an unwinding device (06) for unwinding web-shaped substrate (01) from a substrate supply roll (04), an application device (07) for applying a layer of a pasty medium (02) with a predetermined layer thickness to the web-shaped substrate (01), an NIR drying unit (08) arranged downstream of the application device (07) with at least one NIR radiator (10) for irradiating the pasty medium (02) applied to the web-shaped substrate (01) with infrared radiation in the near infrared range, a hot-air drying unit (12) arranged downstream of the NIR drying unit (08) in the web travel direction for applying heated air of a predetermined temperature to the layer of the pasty medium (02) irradiated with infrared radiation in the near infrared range,and a winding device (16) for winding the web-shaped substrate (01) with the layer of the dried pasty medium (02) applied thereto into a roll (14), in that the hot-air drying unit (12) comprises a first hot-air drying zone (12a) and a second hot-air drying zone (12b) arranged downstream of the first hot-air drying zone in the web travel direction of the web-shaped substrate (01), and in that a first detection device (20) for detecting the layer thickness of the first layer of the pasty medium (02) is arranged upstream of the NIR drying unit (08), viewed in the web travel direction, and in that the radiation power emitted by the at least one NIR radiator (10) is controlled or regulated as a function of the detected layer thickness. [12] Device according to claim 11, characterized bythat the application device (07) for the pasty medium (02) comprises a support roller (07a) which cooperates with a doctor blade (07b), in particular a comma doctor blade, pointed doctor blade or shoe doctor blade, or a slot die which extends over at least a partial section of the width of the web-shaped substrate (01). [13] Device according to one of claims 11 or 12, characterized by that the hot air drying unit (12) is followed by a second detection device (22) for detecting the layer thickness of the dried layer of the pasty medium (02) viewed in the web travel direction, by means of which the layer thickness of the dried layer of the applied pasty medium (02) can be detected. [14] Device according to one of claims 11 to 13, characterized bythat a flat sample section (01a) can be separated from the dried web-shaped substrate (01) in a sampling device (18) arranged downstream of the hot-air drying unit (12) and upstream of the winding device (16). [15] Device according to one of claims 11 to 14, characterized by that the substrate supply roll (04) is rotatable by an associated drive motor (04a) opposite to the withdrawal direction of the web-shaped substrate (01), and that the supply roll (04) is rotated by a predetermined angle of rotation opposite to the withdrawal direction in order to separate the sample section (01a). [16] Device according to one of claims 11 to 15, characterized bythat the web-shaped substrate (01) with the layer of the dried pasty medium (02) applied thereto is moved over a display table (18a) arranged in the sampling device (18), on which display table the sample section (01a) can be separated from the web-shaped substrate (01) by means of one or more roller cutting knives (18b).

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