Method and device for producing printing plate

Abstract

The invention relates to a method for producing a printing plate (15, 15 ') for a screen printing process, in particular a screen printing process, comprising the following steps: S1, providing a support element (6) and S2, forming at least one first region (20, 20a, 20b) and at least one second region (30) on the support element (6); wherein the at least one first region (20, 20a, 20b) is permeable to printing inks used in a screen printing process and the at least one second region (30) is impermeable to inks used in a screen printing process, the at least one first region being formed by irradiating the support element (6) with at least one energy beam.

Description

TECHNICAL FIELD

[0001] The present invention relates to a manufacturing method and a device for manufacturing a printing form for a screen printing process, a printing form for use in a screen printing process and a screen printing method using the printing form. BACKGROUND

[0002] In the field of printing technology, printing ink corresponding to a desired printing image is transferred to the surface of a substrate by means of a printing form. There are various printing processes known today which serve this purpose. One of them is the screen printing process, in particular the screen printing process. In this process, a screen or a fine-meshed fabric is used as a printing form (screen printing form) such that the areas of the printing image which are not to be transferred to the substrate are impermeable to the printing ink. The printing form used for screen printing thus has image areas which consist of a screen or a fabric and are therefore permeable to the printing ink, and non-image areas of the printing form which are impermeable to the printing ink. In the screen printing process, the printing ink is applied to the printing form by means of a squeegee, wherein the printing ink can only pass through the image areas of the printing form to the surface of the substrate which is arranged below the printing form.

[0003] In order to produce a printing form for screen printing, it has been conventional to first tension a grid of right-angled lines on a frame to form a screen or a fabric. Different threads are selected for tensioning on the frame depending on the requirements of the printing image. For example, the threads can be selected depending on their thickness or depending on their surface properties, such as smooth or fibrous. Depending on the distance between the threads which are tensioned parallel in the right-angled X, Y directions, the desired size of the mesh can be formed, through which the printing ink is subsequently pressed by the squeegee to the substrate during printing.

[0004] A further layer is then applied to the surface of the tensioned thread grid in order to close all the meshes of the thread grid. The image to be printed is then applied to this layer and the image is washed off the layer by means of various processes, so that the holes for the image are exposed to form the image areas of the printing form. For this purpose, processes are known in which a film to be exposed and a light source, for example a UV light source, are used (photochemical process). The layer is then washed off after exposure and solidified.

[0005] It is also known that the CTS process (CTS stands for "Computer to Screen") is used in which the image areas or the non-image areas are applied to the layer which closes the meshes of the screen by means of a laser or another light source. There is no need to use a film layer.

[0006] According to the known method for manufacturing a printing form for a screen printing process, a screen or a fine-meshed fabric is first prepared and then the non-image areas are covered with an additional layer, which corresponds to the formation of a template on the screen. The non-image areas of the printing form which are impermeable to the printing ink are thus added to the screen (additive process for the printing form) The drawback of this method is that, because screen printing plates are made of stretched threads, the mesh size and thread thickness are always the same in different areas of the plate, making it impossible to design different mesh sizes / counts for different areas. Furthermore, the manufacturing cost of such screen printing plates is high, energy-intensive, and time-consuming. Completing a full production cycle, including screen reprocessing, requires multiple steps such as coating, drying, exposure, rinsing, drying, demolding, degreasing, and drying. These steps consume large amounts of water, chemical reagents, energy, and time. Summary of the Invention

[0007] Therefore, the object of the present invention is to provide a method for manufacturing a printing plate for a screen printing process, or an apparatus for manufacturing a printing plate for use in a screen printing process, or a printing plate for a screen printing process and a screen printing process for a screen printing process.

[0008] This objective is achieved by the manufacturing method as claimed in claim 1, the manufacturing apparatus as claimed in claim 10, the printing plate as claimed in claim 14, and the screen printing process as claimed in claim 15. Various improvements to the invention are given in the dependent claims. The method can be improved by combining the following apparatus or apparatus features described in the dependent claims, and vice versa. Features of the apparatus or process can also be combined with each other to achieve further improvements.

[0009] The method described in this invention is used to manufacture printing plates for screen printing processes, particularly screen printing processes. The method includes the following steps: providing a support element and forming at least one first region and at least one second region on the support element, wherein the at least one first region is permeable to printing inks used in the screen printing process; and the at least one second region is impermeable to printing inks used in the screen printing process; the at least one first region is formed by irradiating the support element with at least one energy beam.

[0010] Preferably, in this method, only the portion of the support element corresponding to the at least one first region is irradiated with at least one energy beam. More preferably, in this method, the portion of the support element corresponding to the at least one first region is selectively irradiated.

[0011] The support element is preferably a medium or component that is impermeable to printing ink. By irradiating the portion of the support element corresponding to the at least one first region with at least one energy beam, the at least one region can be made permeable to printing ink, while the portion corresponding to the second region will remain impermeable to printing ink and will not be able to be permeated by ink.

[0012] The at least one first region being permeable to the printing ink used in the screen printing process preferably means that the printing ink can pass through the upper side of the support element or printing plate to the lower side of the support element or printing plate, wherein the upper side of the support element or printing plate refers to the side used to apply the printing ink during the screen printing process. Correspondingly, the at least one second region being impermeable to the printing ink used in the screen printing process preferably means that the printing ink applied to the upper side of the support element or printing plate cannot reach the lower side of the support element or printing plate.

[0013] The at least one first region can specifically serve as the image area of ​​the printing plate, which is permeable to printing ink. The at least one second region can specifically serve as the non-image area of ​​the printing plate, which is impermeable to printing ink.

[0014] For example, the method can realize a subtractive production process for printing plates. Since virtually no other materials or substances are needed during the manufacturing process besides the support elements themselves, printing plates can be manufactured in a simpler and / or more cost-effective and / or energy-efficient manner.

[0015] The at least one first region is preferably formed by irradiating the support element with energy rays, wherein a laser in the infrared spectral region is preferred, a laser with a wavelength of 300 nm to 1 mm is more preferred, and a laser with a wavelength of approximately 980 nm is particularly preferred. By using laser irradiation, for example, the detail resolution of the channel structure in different regions of the printing plate can be changed.

[0016] Preferably, the spot size of the at least one energy beam on the surface of the support element is 1μm to 200μm. The focusing size of the energy beam on the surface of the support element is also preferably adjustable. For example, this allows arbitrary mesh and lattice structures to be formed within the at least one first region.

[0017] Preferably, by irradiating the support element with at least one energy beam, a plurality of holes can be formed, particularly ablated, on the support element. These holes preferably form a structure permeable to printing ink on the support element. Specifically, these holes can form a mesh structure, a lattice structure, a honeycomb structure, and / or a sieve structure. Preferably, the mesh structure, lattice structure, honeycomb structure, and / or sieve structure is formed by the holes and spacers separating the holes. In particular, herein, the spacers are understood to be portions of the support element in the at least one first region where the material has not been removed. For example, this allows for the permeability of printing ink.

[0018] Preferably, the at least one first region forms a support structure for the at least one second region, such that, for example, a non-image region (corresponding to at least one second region of the printing plate) can be completely and seamlessly enclosed by the image region (corresponding to at least one first region of the printing plate), for example, represented by the letter "O" or the number "0".

[0019] Preferably, a plurality of holes are formed in at least one first region of the support element, wherein the plurality of holes form a structure, and the structure is formed differently in terms of hole size and / or hole geometry and / or hole geometric arrangement in at least two sub-regions of the at least one first region. This provides, for example, a freely selectable support structure.

[0020] The support element is preferably a sheet or film, and more preferably a plastic film, particularly PET film. Alternatively or additionally, the thickness of the support element is preferably 25 μm to 150 μm, for example, about 50 μm. Specifically, the thickness of the support element refers to the extended thickness from the upper side to the lower side of the printing plate, where the upper side of the printing plate refers to the side where printing ink is applied in the screen printing process, and the lower side of the printing plate refers to the side facing the substrate during screen printing. Preferably, the support element is clamped in a frame before forming the at least one first region and at least one second region. This facilitates, for example, irradiating the support element with an energy beam to form at least one first region.

[0021] The apparatus described in this invention is used to manufacture printing plates for screen printing processes, particularly silkscreen printing processes. The apparatus includes a support platform and an irradiation unit; wherein the support platform is used to receive a support element of the printing plate, and the irradiation unit is designed to generate at least one energy beam to irradiate the support element placed on the support platform. The irradiation unit is designed and / or controlled such that irradiating the support element with the at least one energy beam forms at least one first region and at least one second region on the support element, such that the at least one first region is permeable to printing inks used in the screen printing process, while the at least one second region is impermeable to printing inks used in the screen printing process. This enables, for example, the aforementioned effects regarding the production process and the manufacturing apparatus.

[0022] Preferably, the irradiation unit is designed to specifically direct at least one energy beam to a position on the support element corresponding to the at least one first region. The irradiation unit and the support platform are preferably movably arranged relative to each other within the device. The irradiation unit preferably comprises a plurality of laser diodes, and more preferably comprises a plurality of laser diodes arranged in an array; the plurality of laser diodes preferably emit laser light in the infrared spectral region, more preferably emitting laser light with wavelengths from 300 nm to 1 mm, and particularly preferably emitting laser light with wavelengths of approximately 980 nm. The laser diodes are preferably cooled.

[0023] The printing plate of the present invention is intended for use in screen printing processes, particularly screen printing processes, and includes a support element having at least one first region and at least one second region formed thereon, wherein the at least one first region is permeable to printing inks used in the screen printing process, while the at least one second region is impermeable to printing inks used in the screen printing process; and the at least one first region is formed by irradiating the support element with at least one energy beam.

[0024] The printing plate is preferably a printing plate manufactured by the manufacturing method and / or manufacturing apparatus described above in this invention. The first region is preferably a mesh structure, lattice structure, honeycomb structure, and / or sieve structure, and / or has a plurality of pores through which printing ink can pass. The first region is preferably formed by at least partially removing material from the support element.

[0025] The screen printing method of this invention uses the aforementioned printing plate, wherein the printing plate is placed on the surface of a substrate, and printing ink is applied to the printing plate using a squeegee. The substrate can be, for example, paper, cardboard, plastic, textiles, ceramics, metal, wood, or glass, or any other printable material. The printing ink can be, for example, water-based paint, plastisol coating, UV ink, varnish, adhesive, conductive paste, etc. Attached Figure Description

[0026] Other technical features and practical application details of the present invention can be further illustrated by the following description of each embodiment in conjunction with the accompanying drawings.

[0027] Figure 1 According to one embodiment of the present invention, a perspective schematic diagram of the printing plate manufacturing apparatus is shown; Figure 2a and Figure 2b According to one embodiment of the present invention, a perspective view of the printing plate is shown; wherein, Figure 2b Show and see Figure 2a A magnified view of the printing plate in the image, showing the details in... Figure 2a The circle shown in the middle is indicated by a dashed line; Figure 3 According to one embodiment of the present invention, illustrative steps of a printing plate manufacturing method are shown; Figure 4 According to another embodiment of the invention, a schematic perspective view of the printing plate is shown. Detailed Implementation

[0028] The following is combined with Figure 1 The printing plate manufacturing apparatus according to one embodiment of the present invention will be described. Figure 1 The manufacturing apparatus 1 shown is designed as a drawing ceremony structure, including a substrate 2, a support platform 3 in the form of a support plate, and an irradiation unit 4.

[0029] The substrate 2 includes a linear guiding device, such as two parallel guide rails 5a and 5b extending along a first direction x on the upper side of the substrate 2. The support plate 3 is disposed on the guide rails 5a and 5b to allow it to move relative to the substrate 2 along the first direction x.

[0030] The support plate 3 is designed to accommodate the support element 6 of the printing plate. For this purpose, a frame 7 is provided on the side of the support plate 3 opposite to the substrate 2, and the support element 6 can be clamped in the frame 7.

[0031] Above and at a distance from the support plate 3, the manufacturing apparatus 1 is provided with a support 8, for example, in the form of a rod, which extends along the second direction y. For example, the support 8 can be attached to the substrate 2 via legs 9a and 9b at its ends spaced apart in the second direction y. The irradiation unit 4 is mounted on the support 8 so that it can move along the support 8 in the second direction y.

[0032] The first direction x and the second direction y are arranged at an angle to each other, preferably at right angles; wherein, the support plate 3 is movably arranged relative to the substrate 2 along the first direction x, and the irradiation unit 4 is movably arranged relative to the substrate 2 along the second direction y. Figure 1 In the middle, the two directions x and y are either parallel to the plane formed by the substrate 2 or both are horizontal directions.

[0033] The irradiation unit 4 is designed to generate an energy beam in the form of at least one laser beam 11 to irradiate the support element 6 placed on the support plate 3. For this purpose, the irradiation unit 4 may include, for example, one or more laser diodes, such as a plurality of laser diodes arranged in an array. For example, 16 to 128 laser diodes may be arranged in an array. The laser diodes emit laser light, for example, in the infrared spectral region, and preferably have a wavelength of 300 nm to 1 mm, particularly preferably a wavelength of about 980 nm.

[0034] Since the support plate 3 can move relative to the substrate 2 along the first direction x, and therefore also relative to the bracket 8 along the first direction x; and since the irradiation unit 4 moves relative to the substrate 2 along the second direction y, and therefore relative to the support plate 3 along the second direction y; the laser beam 11 generated by the irradiation unit 4 can be selectively guided to any position of the support element 6 placed on the support plate 3.

[0035] The following is combined with Figure 2a , Figure 2b Figure 3 illustrates a printing plate manufacturing method according to an embodiment of the present invention. The method can be achieved, for example, by the methods described above and / or... Figure 1 The manufacturing apparatus 1 shown is used for this purpose.

[0036] In the first step S1, a support element 6 is provided for the printing plate. In this embodiment, the support element 6 is designed as a film, such as a PET film. The support element 6 itself is impermeable to the printing ink used in the screen printing process. The thickness of the support element 6 can be, for example, 50 μm. In this embodiment, the support element is clamped in a frame 7, such as the one described above. Figure 1 Within the framework 7 described above.

[0037] In the second step S2, a first region 20 permeable to printing ink used in screen printing and a second region 30 impermeable to printing ink used in screen printing are formed on the support element 6. According to one embodiment of the invention, the first region 20 is formed by selectively irradiating the portion of the support element 6 corresponding to the first region 20 using at least one energy beam. For this purpose, for example, it can be done by referring to the above... Figure 1 The manufacturing apparatus 1 described herein uses a laser beam 11 generated by an irradiation unit 4. The irradiation unit 4 is movable along a first direction x and a second direction y such that the laser beam 11 is directed only to the portion of the support element corresponding to the first region 20. If the irradiation unit 4 moves to the portion of the support element corresponding to the second region 30, the laser beam 11 may be turned off, for example, or at least its energy emitted per unit time may be reduced.

[0038] Figure 2a The support element 6 is shown in an exemplary manner, on which two square, spaced apart and different-sized first regions 20 are formed, which are surrounded by a second region 30 of the support element 6.

[0039] To ensure that the first region 20 is permeable to printing ink, an energy beam or laser beam 11 is used to irradiate the portion of the support element 6 corresponding to the first region 20, thereby forming, for example, an ablation-formed hole 21 on the support structure 6. Figure 2bThe enlarged schematic diagram is shown in the figure. In other words, the portion of the first region 20 is irradiated with an energy beam or laser ray 11, partially removing the material of the support element 6, thereby forming holes 21. The holes 21, together with the spacers 22 separating the holes, form a structure similar to fabric or screen that allows printing ink to permeate. The material of the support element 6 in the spacers 22 is not removed.

[0040] like Figure 2b As shown, the holes 21 in the first region 20 are preferably arranged in a grid pattern at regular intervals, and each hole has the same geometry and size.

[0041] According to an improvement of the method of the present invention, the holes 21 can be formed in different shapes in different sub-regions of the first region 20 to form different grids in different sub-regions. For this purpose, for example, holes 21 of different sizes can be selected in the first sub-region and the second sub-region, such as... Figure 2b As shown: Figure 2b The diagram shows the first sub-region 20a of the first region 20 corresponding to the larger of the two squares (in... Figure 2a and 2b In the middle, the square located in the upper right corner) and the second sub-region 20b corresponding to the first region 20 of the two squares (in the square located in the upper right corner) and the smaller square of the two squares. Figure 2a and 2b In the first sub-region 20a, a square located in the lower left corner, and a circular sub-region located within the ring, are provided as a second region 30 within the larger square. The smaller square (second sub-region 20b) also has a circle formed as the second region 30. In the first sub-region 20a, the aperture 21 formed by irradiation by the laser beam 11 is larger in size to form a coarse mesh structure. The aperture 21 in the second sub-region 20b is smaller in size than that in the first sub-region 20a to form a fine mesh structure.

[0042] like Figure 2b As shown, the first region 20 (or the first and second sub-regions 20a, 20b) forms a support structure for the annular or circular second region 30, so that the second region 30 is completely and seamlessly surrounded by the first region 20.

[0043] In the above process, the support element 6, together with the second region 30, forms the printing plate 15 in the first region 20 or 20a, 20b. This is suitable for screen printing processes, especially silkscreen printing.

[0044] Figure 4Another embodiment of the printing plate 15' of the present invention is shown, wherein the support element 6 is clamped within the frame 7. In this embodiment, the support element 6 is a rectangular structure, wherein the outer rectangle is formed as a second region 30, i.e., a region impermeable to printing ink; the inner rectangle disposed within the outer rectangle is formed as a first region 20a having a first coarse mesh structure, i.e., a region permeable to printing ink. Within the inner rectangle (first region 20a), a star-shaped second region 30 is formed, i.e., a region impermeable to printing ink; conversely, within the star-shaped second region 30, a star-shaped first region 20b is formed, i.e., a region permeable to printing ink. The star-shaped first region 20b has a smaller mesh structure than the first region 20a forming the inner rectangle. This allows, for example, a better rendering of the fine serrations of small stars. The first region 20a forming the inner rectangle forms the support structure for the star-shaped second region 30, which is not connected to the second region 30 forming the outer rectangle, but is completely and seamlessly surrounded by the first region 20a (inner rectangle).

[0045] In order to refer to the above Figure 2a , 2b as well as Figure 4 The described printing plates 15 or 15' are used in screen printing processes, particularly silkscreen printing, where the plates 15 or 15' are placed on a substrate (such as paper). Printing ink is then applied to the plates 15 or 15' using a squeegee. The printing ink can only reach the substrate (image area) through the regions 20, 20a, and 20b formed on the plates, while the second region 30 of the plates is impermeable to the printing ink, thus preventing the ink from reaching the substrate at the regions corresponding to the second region (non-image area). For example, water-based inks can be used as printing inks.

[0046] This invention is not limited to the embodiments described above. On the contrary, various modifications can be made to the embodiments described above within the scope of protection of this invention.

[0047] For example, the support element 6 shown in the attached figure is a rectangular structure, which is clamped within the rectangular frame 7. However, the support element and / or frame can also take any other arbitrary geometric shape, such as circular or elliptical, or regular or irregular polygonal shapes, etc. This also applies to Figure 1 Other components of the manufacturing apparatus shown, particularly the substrate 2 and the support plate 3.

[0048] The printing plate may have one or more first regions and / or second regions, wherein the first regions may employ the same or different grid structures. The at least one first region and at least one second region are preferably selected according to the desired printing pattern. The holes forming the grid structure of the at least one first region may be, for example, square, circular, or other arbitrary shapes. For example, the grid structure defined by the shape and size of the holes and the distribution of the holes and the spacers separating them is preferably selected so that the printing ink used in the screen printing process can pass through the holes.

[0049] In the above embodiments, the support element is designed as a film, such as a PET film. Other types of support elements, such as (thin) sheets, may also be used. Preferably, the support element is selected in terms of its shape, size, and material such that it is itself impermeable to printing inks used in the screen printing process, and is permeable to printing inks in at least some areas after the respective first area is selectively irradiated by at least one energy beam.

[0050] The scope of protection of this invention is not limited to the manufacturing method and apparatus described above. For example, Figure 1 In the illustrated device, a linear guide is provided on its substrate, which allows the support plate to move along a first direction x, and the irradiation unit is configured to move on a support along a second direction y. Alternatively, the support plate may be fixed in the manufacturing apparatus, and the irradiation unit may be configured to move both along the first direction x and the second direction y, and vice versa.

[0051] Alternatively, a row-type imagesetter with multiple individually controllable irradiation elements, such as laser diodes or laser diode arrays, can be used as the irradiation unit. This row-type imagesetter extends across the entire width (e.g., the second direction y) of the area to be exposed and is configured to move relative to the support plate in the width direction (e.g., the first direction x) of the area to be exposed. By switching each individually controllable irradiation element of the row-type imagesetter on and off, a desired intensity distribution can be formed at a location on the support element corresponding to the first area to be exposed.

[0052] Alternatively, an irradiation unit that generates at least one energy beam, particularly a laser beam, may be used. This energy beam is selectively guided by deflecting optics, such as one or more deflectable mirrors, to a location on the support element corresponding to the at least one first region.

[0053] Typically, an irradiation unit designed and / or controlled to selectively irradiate portions of a support element corresponding to the at least one first region using at least one energy beam can be used, such that after irradiation, the first region is permeable to printing inks used in a screen printing process.

Claims

1. A method for manufacturing a printing plate (15, 15') for screen printing processes, particularly silk screen printing processes, comprising the following steps: S1: Provides support elements (6); and S2: At least one first region (20, 20a, 20b) and at least one second region (30) are formed on the support element (6), wherein, The at least one first region (20, 20a, 20b) is permeable to printing inks used in the screen printing process, and the at least one second region (30) is impermeable to printing inks used in the screen printing process. The at least one first region is formed by irradiating the support element (6) with at least one energy beam.

2. The method according to claim 1, characterized in that: The support element is irradiated with laser beam (11) to form the at least one first region (20, 20a, 20b).

3. The method according to claim 2, characterized in that: The laser beam (11) is a laser in the infrared spectral region and / or has a wavelength of 300 nm to 1 mm, preferably about 980 nm.

4. The method according to any one of claims 1 to 3, characterized in that: A plurality of holes (21) are formed, in particular ablated, on the support element (6) by irradiating the support element (6) with at least one energy beam within the at least one first region (20, 20a, 20b), wherein the plurality of holes (21) preferably form a structure on the support element (6) through which the printing ink can pass.

5. The method according to any one of claims 1 to 4, characterized in that: By irradiating the support element (6) with at least one energy beam within the at least one first region (20, 20a, 20b), a plurality of holes (21) are formed on the support element, wherein the plurality of holes form a grid; and The mesh is formed in at least two sub-regions (20a, 20b) of the at least one first region such that the size and / or geometry of the hole (21) and / or geometric arrangement of the hole (21) are different.

6. The method according to any one of claims 1 to 5, characterized in that: The supporting element (6) is a plate or film.

7. The method according to claim 6, characterized in that: The film is a plastic film, preferably a PET film.

8. The method according to any one of claims 1 to 7, characterized in that: The thickness of the support element (6) is 25μm to 150μm, preferably about 50μm.

9. The method according to any one of claims 1 to 8, characterized in that: Before forming the at least one first region and at least one second region, the support element (6) is clamped in the frame (7).

10. An apparatus for manufacturing printing plates (15, 15') for screen printing processes, particularly silk screen printing processes, comprising: Support platform (3), which is designed to hold the support element (6) of the printing plate; as well as Irradiation unit (4), which is designed to generate at least one energy beam to irradiate the support element (6) placed on the support platform (3). The irradiation unit (4) is designed and / or controlled to irradiate the support element (6) with at least one energy beam, forming at least one first region (20, 20a, 20b) and at least one second region (30) on the support element (6), such that the first region is permeable to printing ink used in screen printing, while the second region is impermeable to printing ink used in screen printing.

11. The apparatus according to claim 10, characterized in that: The irradiation unit (4) is designed to specifically direct at least one energy beam to a portion of the support element corresponding to the at least one first region (20, 20a, 20b).

12. The apparatus according to claim 10 or 11, characterized in that: The irradiation unit (4) and the support platform (3) are configured in the device (1) to be movable relative to each other.

13. The apparatus according to any one of claims 10 to 12, characterized in that: The irradiation unit (4) includes a plurality of laser diodes, preferably a plurality of laser diodes arranged in an array; the plurality of laser diodes preferably emit lasers in the infrared spectral region and / or have a wavelength of 300 nm to 1 mm, preferably about 980 nm.

14. A printing plate for screen printing processes, particularly silk screen printing processes, comprising: A support element (6) having at least one first region (20, 20a, 20b) and at least one second region (30); wherein the at least one first region is permeable to printing ink used in the screen printing process, while the at least one second region is impermeable to printing ink used in the screen printing process. The at least one first region (20, 20a, 20b) is formed by irradiating the support element (6) with at least one energy beam.

15. A screen printing method using the printing plate as described in claim 14, wherein, The printing plates (15, 15') are placed on the surface of the printing material, and printing ink is applied to the printing plates (15, 15') using a doctor blade.

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