EP3843999B1 - Method for setting the layer thickness of a covering coating material to be applied to a substrate by an application device - Google Patents

Description

The invention relates to a method for adjusting a layer thickness of a covering coating material to be applied to a substrate by an application device according to the preamble of claim 1.

the DE 38 30 121 A1 describes a method for setting a predetermined printing standard, defined by a pair of values for full tone density/raster dot change, in an autotypical printing process, which can be influenced by a plurality of printing parameters, on an autotypically working multicolor printing machine with adjustable actuators for influencing one of these printing parameters, namely the supply of printing inks adjacent ink zones of a printing material, wherein for at least one printing ink on measuring fields also printed within the ink zones, full tone densities and halftone dot changes are repeatedly determined densitometrically and the actuators are regulated as a function thereof, wherein at the beginning of the setting at least one value pair solid tone density/halfton dot change taking into account the correlations between the full tone density and the halftone dot change is examined for its conformity with the printing standard, the printing process is preselected if the conformity deviates from a th tolerance range is aborted, to change the current function "full tone density, halftone dot change" at least one printing parameter other than the one affecting the ink supply is changed, then the printing process is resumed and then, if necessary, each of these process steps is repeated until the conformity is at least within the preselected tolerance range .

through the DE 38 18 405 A1 is a method for determining the coloring for the different paper-color combinations in operational practice in the Printing industry comprising all the features of the preamble of claim 1 known, with a uniform color profile set on the printing press, the same amount of ink offered zonally and the thickness of the ink application is determined by an ink removal area of a printing aid.

through the US 2015/0 090 136 A1 a method is known for controlling the thickness of an ink film, the ink film being applied to a printed substrate in a lithographic printing machine that includes a plurality of printing units, each printing unit including a blanket cylinder, a plate cylinder, a take-off roller and an inking unit, comprising: (a) Filling the ink cylinder in one or more of the plurality of printing units, the filling including the steps of: arranging all printing units of the printing press in a non-imprint position, each printing unit including a blanket cylinder, moving the take-off roller in the one or more printing units of the plurality of printing units into contact with the blanket cylinder of the printing unit and thereafter driving the inking unit, plate cylinder, blanket cylinder and take-up roller and thereby transferring ink from the inking unit to the plate cylinder, from the plate cylinder to the blanket cylinder and from the blanket cylinder to the pickup me roller, (b) moving the take-away roller out of contact with the blanket cylinder of the printing unit in the one or more printing units of the plurality of printing units, (c) placing the one or more printing units in impression position, (d) printing on the substrate with the one or more print engines as the substrate moves through the print engine, (e) measuring an optical density on the moving substrate with an optical sensor, (f) comparing the measured optical density to a predefined metric, and if the measured optical density within one is within the predefined metric, continuing to print on the substrate and if the measured optical density is outside the predefined metric, repeating steps (a) through (f).

through the DE 34 11 836 A1 a method is known for controlling the supply of ink and dampening solution in planographic printing presses by measuring control marks that are also printed and then evaluating the measured values, with the measurement values for determining the ink density and the dampening being obtained on the same control marks, signals being created which are used for evaluation dampening and ink density values are used, after which the existing dampening and ink density values are calculated and a comparison is made with specified target values within specified tolerance limits by a microcomputer, with the formation of differential signals between target and actual values generating separate control signals for the control of ink and Dampening are generated.

through the DE 10 2007 061 397 A1 discloses a printing machine with a device for transferring image layers from a transfer film onto sheets, with at least one application device for an imagewise coating of the sheets with an adhesive and with a coating device downstream from this for transferring the image layers from the transfer film onto the sheets, with between a measuring system directed at the sheets is arranged between the application device and the coating device, with the measuring system being able to measure the opacity of the adhesive layer and/or with the measuring system being able to detect control fields and/or measuring strips outside of the printed image.

through the DE 32 26 144 A1 is a method for adjusting the ink metering in printing presses with an objective pre-determination of ink metering variables including machine influencing variables known, with the detection of the change in the influence of the machine influencing variables, the paper quality and the color properties on the optical density after a presetting of the ink dosage, a measurement of the zonal optical density of the printed solid areas of a removed printed product is carried out, the comparison between the existing and the required optical density is carried out and, if the difference in the density values lies outside a specified tolerance range, the Calculation of the printed surface area and the resulting ink knife gap is again carried out iteratively and the adjustment of the ink knife is carried out and these steps are repeated until the difference between the existing and the required optical density is within the specified tolerance range. through the DE 10 2014 011 151 A1 a method for color control in printing machines with a computer by detecting color areas on a surface to be printed with a color measuring device is known, the to be printed

surface is a printing material, the printing material being coated with opaque white, the color measuring device recording a plurality of measured color values of opaque white and the computer comparing the recorded color measurement values of the opaque white with one another or against a reference color value of the opaque white and storing the deviations ascertained during the comparison in the computer, with the printing material coated with opaque white is overprinted with color measuring patches, the overprinted color measuring patches being recorded by the color measuring device and the computer taking into account the influence of the stored deviations determined when comparing the inking of the color measuring values of the color measuring patches on which opaque white is based with the target color values of the printing template.

through the DE 10 2007 005 018 A1 a method for color control of copies of a printing press is known, in which a substrate, which appears dark in a standard-compliant color measurement, is printed with at least one printing ink, which is lighter than the substrate, and at least one color value of the printing ink is determined from a measured variable, wherein the color value of the at least one Printing color is controlled using a fixed reference value of a color location in the color space that is lighter than the printing color.

In manufacturing technology, coating is a main group of manufacturing processes according to DIN 8580 (2003-09 edition), which are used to apply a firmly adhering layer of shapeless material to the surface of a solid carrier material, also known as a substrate. The corresponding process and the applied layer itself are referred to as coating.

The following is about a liquid or a pasty, i. H. to apply a brushable or powdered coating material to a substrate in a machine coating process. In this case, after it has been applied and optionally after physical drying and/or chemical curing, the coating material on the substrate preferably forms a layer that is thin in comparison to the material thickness of the substrate, e.g. B. in the micrometer range or in the nanometer range. The coating materials also include film-forming paints or paints, which also include z. B. in the graphics industry or in printing technology used printing inks, paints, inks or inks and z. B. coating colors used in the paper industry for surface finishing are counted.

In the embodiment preferred here, the substrate is in the form of a printing material. The printing material consists in particular of paper, cardboard, cardboard, sheet metal, textiles, glass, ceramics or a foil made of metal or a plastic. a z. B. from paper, cardboard, cardboard, foil, sheet metal or textiles formed printing material is in particular flat as a sheet or as a web of material. a z. B. from sheet metal, plastic, glass or ceramic formed substrate can also be used as a hollow body, z. B. as a container, preferably as a can or as a cup or as a bottle or as a tube. The one on the respective substrate The coating material to be applied is preferably a colorant, ie a coloring inorganic or organic substance which can be of natural or synthetic origin and has pigments or at least one dye.

The coating to be carried out according to the invention takes place in an industrial process in a machine processing the respective substrate, or in a printing press or in a paper processing machine.

The coating material to be applied to the respective substrate can be opaque or glazing. A translucent coating material can be transparent, i. H. image or view permeable, or translucent, d. H. be partially translucent. In contrast, a covering coating material is opaque, at least above a certain layer thickness applied to the respective substrate, i. H. opaque. Translucency and opacity are therefore reciprocal properties. The opacity is therefore a measure of the opacity or turbidity of translucent, i. H. scattering translucent materials and layers. In the paper sector, it is common to specify the opacity for a sheet or a sheet according to ISO 2471. The opacity is approximately defined there as 0=100% minus light transmission. A sheet of paper with a light transmission of 1% has an opacity of 99%.

In printing technology, opaque printing inks are often used for functional or decorative reasons. These inks can B. basic colors such as red, green and blue or cyan, yellow, magenta and black or opaque white or various metallic colors such. B. be gold or silver.

A in an industrial process with an application device z. B. in a printing press or in a paper processing machine made order of a coating material on a substrate is used to support the production of a desired quality of the coating during ongoing operation of the Printing machine or the paper-processing machine inline, ie during production within the respective machine, usually with a non-contact detection device, e.g. B. with a working in an optoelectronic measuring method detection device, preferably densitometrically or spectrophotometrically controlled in particular continuously. With this check, it is of particular interest to gain knowledge of the layer thickness already applied to the respective substrate. The problem is that when checking an opaque coating material in a densitometric or spectrophotometric measuring method, e.g. B. for the optical density or a brightness value or a color point of the coating material in question from a certain applied layer thickness, namely at the latest when an opacity of 100% is reached. Consequently, there is a risk that the covering coating material will be applied to the respective substrate in an unnecessarily large layer thickness in the industrial process, which is at least uneconomical and also unnecessarily weighs down the respective substrate.

An application device arranged in a printing press or in a paper processing machine for the mechanical application of a coating material to a substrate preferably has a metering device controlled or regulated by a control unit. B. a width of at least one outflow opening of a reservoir storing the coating material and/or a stroke of a lifter transferring the coating material, with the lifter transferring the coating material from a reservoir storing it to a roller applying or transferring it, and/or a rotational speed of a den Coating material applying or transferring roller, in particular a ductor, each influences a quantity of the coating material to be applied to the substrate.

The invention is now based on the object of a method for setting a To create a layer thickness of an opaque coating material to be applied to a substrate by an application device in a printing machine or in a paper processing machine, with which the layer thickness of the opaque coating material applied by the application device to the substrate in question is reduced to a predetermined value, or to a layer thickness with a opacity of 100% is set and/or kept constant at this value.

The object is achieved according to the invention by the features of claim 1. The dependent claims relate to advantageous refinements and/or developments of the solution found.

The advantages that can be achieved with the invention consist in particular in the fact that the layer thickness of the covering coating material applied by the application device to the relevant substrate can be set to a value previously specified in the control unit and/or can be kept constant at this value. As a result, the consumption of the covering coating material is optimized, particularly in an industrial process carried out by a printing machine or a paper processing machine.

Exemplary embodiments of the invention are shown in the drawings and are described in more detail below.

Fig. 1

eine Maschineneinheit einer Druckmaschine mit einer Auftrageinrichtung;

Fig. 2

einen Bogen mit mindestens einem Druckbild und mit einem Messstreifen.

Show it:

1

a machine unit of a printing machine with an application device;

2

a sheet with at least one printed image and with a measuring strip.

The invention is explained below without limitation using the example of a printing press, preferably a rotary printing press, in particular a sheet-fed rotary printing press. The printing press can start its printing process e.g. B. in an offset printing process or in a flexographic printing process or in a screen printing process or in an inkjet printing process.

1 shows a simplified and schematic section of the printing press, a machine unit 01 with a transport device arranged in a frame 03 for transporting at least one e.g. B. each formed as a sheet 13 substrate ( 2 ), This transport device z. B. at least one transport cylinder 02, in the preferred embodiment in the transport direction T of the at least one substrate, preferably several, e.g. B. three or more transport cylinders 02 in a row. The respective direction of rotation of the transport cylinders 02 is indicated by a directional arrow. At the respective transport cylinders 02 z. Holding elements, e.g. designed as grippers or as suction devices, fix the respective substrate to the relevant lateral surface of the respective transport cylinder 02 during its transport from one transport cylinder 02 to the next transport cylinder 02. The respective transport cylinders 02 are e.g. B. formed several times, so that one behind the other two or three or even more substrates are arranged or at least can be arranged on their respective circumference.

The one in the 1 The machine unit 01 shown has, in cooperation with one of the transport cylinders 02, an application device 04 for applying an opaque coating material to the respective substrate transported by the relevant transport cylinder 02 during its rotation. This opaque coating material is an opaque printing ink that is designed as a base color or alternatively as an opaque white or as a metallic color. A layer thickness of the Application device 04 applied to the substrate is z. B. in the micrometer range or in the nanometer range. In a printing press, the application device 04 is e.g. g. as a metering device that is controlled or regulated by a control unit 06, with this metering device being configured in each case by adjusting the width of at least one outflow opening of a reservoir storing the coating material, e.g. B. ink fountain or squeegee system 09, and/or a cycle of a lifter transferring the coating material and/or a rotational speed of a roller transferring or applying the coating material, e.g. g. ductor 07 and/or applicator roller 08, each influences the quantity of the coating material to be applied to the substrate. The application device 04 can be positioned in the printing machine in the transport direction T of the at least one substrate, e.g. B. be arranged in front of a printing press belonging to the printing unit to z. B. first apply an opaque white to the respective substrate before the layer formed from the opaque white is at least partially overprinted with at least one other printing ink. On the other hand, the application device 04 can also be arranged in the printing press in the transport direction T of the at least one substrate after a printing unit belonging to the printing press, in order to at least partially overprint at least one printing ink that has already been applied to the respective substrate and thus e.g. B. to produce a backlit printed product with a special effect. The covering coating material can be applied to the respective substrate over the entire surface, partially or in a rastered manner. The layer of the covering coating material applied to the respective substrate with the application device 04 in the printing press can also be or be underlaid with a primer layer for better adhesion. If necessary, the covering coating material can also be applied several times to the same substrate in the printing machine, in which case z. B. more than just a single machine unit 01 is arranged, each with an application device 04. Furthermore, in the printing press in transport direction T of the at least one substrate, a device for physical drying and/or for chemical hardening may be provided, the device for physical drying z. B. as a hot air dryer 11 and / or as an infrared dryer 11 and the device for chemical hardening z. B. as a UV dryer 11 are formed.

The layer thickness of the coating material applied to the substrate using application device 04 is monitored using a detection device 12, with detection device 12 collecting measured values from the covering coating material applied to the respective substrate while the printing press is in operation, ie inline during production. The detection device 12 arranged within the printing press is connected to the control unit 06, the control unit 06 determining a value for the opacity of the layer of coating material applied to the substrate from the measured values provided by the detection device 12. The signal paths and signal directions from the detection device 12 via the control unit 06 to the application device 04 are shown in FIG 1 indicated by directional arrows. In particular, operating data and/or control data can also be provided bidirectionally between the control unit 06 and the application device 04. It is provided that, following the determination of the current value for the opacity of the layer of coating material already applied to the substrate, control unit 06 sets the layer thickness of this coating material to be applied by application device 04 to at least one additional substrate in such a way that the coating material applied with application device 04 a layer of coating material to be applied to the at least one additional substrate for the opacity, e.g. B. by means of a manual or automated input fixed, preferably freely selectable value is generally achieved within the framework of permissible tolerances and/or generally maintained within the framework of the specified tolerances during ongoing operation of the printing press. In the preferred embodiment, the control unit 06 sets the application unit 04 in such a way that the application unit 04 is applied to the at least one additional substrate applied layer of the coating material for the opacity reaches a value in the range of at least 95% to 100% and / or maintains this during operation of the printing press.

The detection device 12 preferably works without contact and/or with an optoelectronic measuring method and/or densitometrically or spectrophotometrically. In a particularly preferred embodiment, the detection device 12 is configured as a camera, e.g. g. as a greyscale camera or as an RGB camera or as a CMYK color measurement camera, with control unit 06 e.g. B. by evaluating one or more images recorded by the camera of the substrate, d. H. the current value for the opacity of the layer of coating material applied to the substrate is determined from at least one photographic image or from the image data on which it is based. In a further embodiment variant, the detection device 12 is designed as a reflection light scanner. Control unit 06 sets the layer thickness of the coating material applied to the substrate by application device 04, based in particular on at least one opacity value determined during a growing layer build-up, e.g. B. in a run-up of the printing press or in another operating phase of the printing press, in which the translucency of the layer of coating material applied to the substrate steadily decreases to opacity.

2 shows a substrate designed as a sheet 13 with at least one printed image 14 and with a measuring strip 16 extending transversely to the transport direction T of the substrate in question, in particular across the width of the printed image 14. The measuring strip 16 has a plurality of measuring fields 17 lined up, with individual measuring fields 17 . B. full surface or gridded z. B. in the printing press according to 1 are each coated with a coating material in an industrial process using the application device 04 described. In the preferred embodiment, the basis of 1 described detection device 12 on at least one measuring field 17 in the measuring strip 16 of sheet 13, with control unit 06 connected to detection device 12 determining the respective value of the opacity of the layer of coating material applied in measuring strip 16 of sheet 13 in at least one measuring field 17. It can be provided that the control unit 06 determines the respective value of the opacity of the layer of coating material applied in each case from several or all measuring fields 17 in the measuring strip 16 of the sheet 13 and, depending on the value determined for the opacity of the layer of coating material applied in each case sets the layer thickness to be applied by the application device 04 to at least one subsequent sheet 13 individually, i.e. as required, for several or each of the zones 18 corresponding to at least one measuring field 17 and extending in the transport direction T of the sheet 13 in question. A further embodiment variant provides for the respective value of the opacity of the respectively applied layer of the coating material to be recorded at at least one preferably selectable position in the at least one printed image 14 printed on the sheet 13 instead of or in addition to the detection in at least one of the measuring fields 17 of the measuring strip 16 capture.

According to the invention, it is provided that the coating material is generally applied simultaneously to different points on the sheet 13 in question by means of the application device 04 in the same printing process. The different locations on the relevant sheet 13 are z. B. at least two different measuring fields 17 of the same measuring strip 16 or at least two different elements in the same printed image 14. It is provided that the coating material is applied to at least one first location on the relevant sheet 13 in a grid having a plurality of grid points and at least one other second place on the relevant sheet 13 is applied over the entire surface. In concrete terms, this means, for example, that the coating material is applied by means of the application device 04 in the same printing process, in particular at least in one of the measuring fields 17 of the relevant measuring strip 16 in a plurality of grid points having grid and in at least one other measuring field 17 of this measuring strip 16 is applied over the entire surface. a z. B. as a measuring field 17 trained first point on the sheet 13 in question, where the coating material is applied in a grid, is also referred to as a grid, whereas a z. B. as a measuring field 17 formed second point on the sheet 13 in question, where the coating material is applied over the entire surface, is also referred to as a solid field. From the data recorded by the recording device 12 at the respective first and second point on the relevant sheet 13, the control unit 06 determines, e.g. B. image data, a respective value for the optical density of the layer of coating material applied at the relevant points on the sheet 13.

The control unit 06 also sets the respective value DR for the optical density determined from a grid field to the respective value DV for the optical density z determined from a solid tone field. B. by forming a quotient DR / DV in a ratio. Since the optical density is proportional to the amount of per unit area on the sheet 13 at the relevant locations on the sheet 13 z. B. in the respective measuring fields 17 of the measuring strip 16 applied coating material, the value DR for the optical density determined in a grid field in a printing process is at least initially lower than the value DV for the optical density determined in a full tone field. However, with increasing layer thickness of the coating material applied in a grid field, e.g. B. due to a spread of the local halftone dots and/or optical effects, an increase in the optical density determined in the relevant halftone field is accompanied by an increase in the optical density from the respective value DR for the optical density determined from a halftone field and the respective value DV for the ratio formed optical density changes significantly. The control unit 06 now lays down the layer thickness currently applied by the application device 04 to the relevant sheet 13 in the current printing process, particularly if it detects a significant change in the ratio formed from the optical densities, ie as a function of this determination of the coating material, for which the value DR for the optical density determined in a grid field corresponds to the value DV for the optical density determined in a full tone field, as that layer thickness of the coating material with an opacity value of 100%. The significant change in the ratio formed from the optical densities can e.g. B. consist in the value of a quotient formed from these optical densities in a series of several consecutive data collections, ie surveys of these optical densities, initially approaching the value 1, but then for a preferably previously determined number of subsequent data collections at least almost unchanged Value 1 remains. In a series of several successive surveys of the relevant optical densities, the control unit 06 thus checks a course or a behavior of this ratio for a significant change, ie a change that exceeds permissible tolerance limits. The layer thickness of the coating material with an opacity value of 100% is determined e.g. B. in that the control unit 06 stores the currently provided operating data and/or control data of the application device 04 in a storage device 19 in association with an opacity value of 100% for the layer thickness of the coating material. Following the determination made, control unit 06 sets the layer thickness of the coating material to be applied by application unit 04 to at least one additional substrate, i.e. in particular at least one additional sheet 13, in such a way that the layer of the coating material to be applied to the at least one additional substrate using application unit 04 Coating material for the opacity has the value of 100% in the further printing process, in particular during operation of the printing press or the paper processing machine and thus maintains it.

Reference List

01

machine unit

02

transport cylinder

03

frame

04

application setup

05

-

06

control unit

07

ductor

08

application roller

09

squeegee system

10

-

11

hot air dryer; infrared dryers; UV dryer

12

detection device

13

bow

14

print image

15

-

16

gages

17

measuring field

18

Zone

19

storage facility

20

-

DR

Optical density value in a grid

dv

Value for the optical density in a solid patch

T

transport direction

Claims (11)

1. Method for setting a layer thickness of a covering coating material to be applied to a substrate by an application device (04), wherein the coating material is applied to the substrate in a printing machine or in a paper-processing machine, wherein the coating material is applied at various points on the substrate in question by means of the application device (04) in a machine process, wherein at each of at least one first point on the substrate in question the coating material is applied in a grid having a plurality of grid points, and at each of at least one other second point on the substrate in question the coating material is applied over the full area, wherein each first point in question on the substrate in question forms a grid zone and each second point in question on the substrate in question forms a solid zone, wherein a control unit (06) connected to a sensing device (12) determines, from data captured by the sensing device (12) at the respective first and second point on the substrate in question, a respective value for the optical density of the layer of the coating material applied at the points in question on the substrate, wherein at least one covering printing ink is used as the coating material, wherein the covering printing ink in question is formed as a primary colour, characterized in that the sensing device (12) continuously collects measured values during ongoing operation of the printing machine or of the paper-processing machine, wherein the application of the coating material to the substrate in question during the ongoing operation of the printing machine or of the paper-processing machine, which is carried out by the application device (04), is continuously monitored during production within the respective machine by the sensing device (12), wherein the control unit (06) defines the layer thickness of the coating material currently being applied to the substrate in question by the application device (04) during the ongoing machine process, at which layer thickness the value (DR) for the optical density determined in a grid zone corresponds to the value (DV) for the optical density determined in a solid zone, as that layer thickness of the coating material that has an opacity value of 100%.
2. Method according to claim 1, characterized in that the control unit (06) sets the layer thickness of the coating material to be applied to at least one further substrate by the application device (04) such that the layer of the coating material to be applied to the at least one further substrate by the application device (04) has for the opacity a value of 100% during the further ongoing operation of the printing machine or of the paper-processing machine.
3. Method according to claim 1 or 2, characterized in that, in order to define the layer thickness of the coating material that has an opacity value of 100%, the control unit (06) stores the currently provided operating data and/or control data of the application device (04) in a memory device (19) in association with the opacity value of 100% for the layer thickness of the coating material.
4. Method according to claim 1 or 2 or 3, characterized in that the control unit (06) relates the respective value (DR) for the optical density that is determined from a grid zone to the respective value (DV) for the optical density that is determined from a solid zone and then defines the layer thickness of the coating material currently being applied to the substrate in question by the application device (04) during the ongoing machine process as that layer thickness of the coating material that has an opacity value of 100% when the control unit (06) identifies a significant change in the course or behaviour of this relationship in a series of multiple successive collections of the optical densities in question.
5. Method according to claim 1 or 2 or 3 or 4, characterized in that at least one measuring field (17), respectively formed as a grid zone, of a measuring strip (16) formed on the substrate in question and having multiple measuring fields (17) is used, along with at least one measuring field (17), respectively formed as a solid zone, of the same measuring strip (16).
6. Method according to claim 1 or 2 or 3 or 4 or 5, characterized in that a printing stock is used as the substrate, wherein the printing stock consists of paper, cardboard, paperboard, sheet metal, textiles, glass, ceramics, or a film made of metal or of a plastic, and/or wherein the printing stock is designed as a hollow body or in flat form as a sheet (13) or as a material web.
7. Method according to claim 1 or 2 or 3 or 4 or 5 or 6, characterized in that a coating material in liquid, paste or powder form is used.
8. Method according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7, characterized in that a colorant is used as the coating material, wherein the colorant is designed as a colour-imparting inorganic or organic substance, and/or wherein the colorant is of natural or synthetic origin, and/or wherein the colorant comprises pigments or at least one dye.
9. Method according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8, characterized in that the sensing device (12) operates in a contactless manner and/or by an optoelectronic measuring method and/or by densitometry or by spectrophotometry.
10. Method according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9, characterized in that the application device (04) has a metering device controlled or regulated by a control unit (06), wherein this metering device influences a respective quantity of the coating material to be applied to the substrate in question by setting a width of at least one outlet opening of a reservoir that stores the coating material and/or a cycle of a siphon that transfers the coating material and/or a rotational speed of a roller (07; 08) that applies or transfers the coating material.
11. Method according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10, characterized in that an opaque white or a metallic colour is used instead of the primary colour.

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