Apparatus and process for decorating ceramic articles

Abstract

The process for decorating a ceramic article comprises at least the following phases:-providing at least one ceramic medium (S) to be decorated having at least one exposed surface ("Sa") and at least one laying surface ("Sb") opposite one another; -applying a water-repellent liquid (L) on the exposed surface ("Sa") by means of a first printer, preferably a first digital inkjet printer (4), according to a predefined design (D); spreading an aqueous glaze (C) on the exposed surface (Sa), wherein the spreading is carried out by means of the dispensing device (5); -applying at least one ceramic ink on the exposed surface (Sa) by means of a second printing press, preferably a second digital inkjet printing press (10), the design of which is coordinated with the predefined design (D).

Description

Technical Field

[0001] The present invention relates to an apparatus and a process for decorating ceramic articles such as tiles and / or slabs. Background Art

[0002] To date, there is a general demand in the ceramic industry for new surface effects which are increasingly similar to natural stone or other textured types, ie having reliefs and / or depressions to define three-dimensional effects.

[0003] The proprietor notes that these types of effects are generally obtained during the forming phase of the article, that is, during the process of pressing the ceramic powder into the ceramic medium.

[0004] The shaping stage is carried out by using a pad or roller or an engraved tape which, in the case of a textured effect, has a corresponding pressing surface provided with reliefs and / or depressions which reproduce the reverse side of the effect to be obtained.

[0005] In this way, the resulting ceramic medium itself has a textured exposed surface that will be covered by the glaze applied in a subsequent decoration stage.

[0006] The owners point out that these processes and the associated equipment do have a number of disadvantages.

[0007] In fact, they are characterized by limited flexibility of use, since, using a single piece of equipment, the ceramic media obtained all have the same surface structure.

[0008] It is therefore obvious that in order to obtain ceramic objects with different aesthetic effects it is necessary to equip oneself with several engraved pads and / or rollers and / or tapes of various shapes, which requires a high investment that is difficult to justify, especially in the case of small and medium-sized production batches.

[0009] In any case, even if a large number of different engraved pads and / or rollers and / or tapes were available, the number of aesthetic effects that could be obtained would still be limited, and their replacement would result in long downtimes and, therefore, low production output.

[0010] The owner notes that other known types of techniques involve applying a binding material to the exposed surface of the ceramic media and subsequently depositing a granular material on the binding material, the granular material protruding from the exposed surface itself. The excess granular material must then be removed.

[0011] According to the owner, the limitations of this technology are particularly that it cannot achieve high definition, so the texture effects produced are not as clear and defined as the above methods.

[0012] Another known type of technique known to the owner consists in applying a water-repellent liquid to the exposed surface and then applying a glaze to that surface, which, since it contains water, accumulates on the areas without the water-repellent liquid, thereby obtaining a textured effect.

[0013] However, in the opinion of the owner, this known technology also has some disadvantages, since the glaze dispensing devices commonly used (such as airless spray guns) involve on the one hand the use of glazes with little or no water content, thus making the effect of the water-repellent liquid blurred or imperceptible, and on the other hand lead to an undesirable amount of glaze applied, which produces a flattening effect of the structure.

[0014] In the following description, the term "water-repellent liquid" generally refers to a hydrophobic liquid or a reserve liquid.

[0015] Another disadvantage of the prior art is that the design of the textured surface is not consistent with the image printed thereon. In fact, in the prior art, the embossed portion is completely inconsistent with the graphic printed on the tile, which results in an irregular effect. Summary of the invention

[0016] The main purpose of the present invention is to devise a process and an apparatus which allow to obtain, in a smooth and flexible way, ceramic articles with a textured surface effect, wherein the graphics applied thereto are coordinated with the design of the textured surface.

[0017] Within this aim, an object of the invention is to achieve a variety of different structural aesthetic effects with a single device.

[0018] Another object of the invention is to devise a process and an apparatus which allow achieving a high surface and high three-dimensional structural definition on the articles thus decorated.

[0019] Yet another object of the present invention is to optimize the amount of glaze applied during the decoration phase of the ceramic medium in order to reduce the amount of material used and the related costs to the necessary minimum while avoiding flattening of the three-dimensional structural effect.

[0020] Another object of the present invention is to devise a device and a process for decorating ceramic articles which allow overcoming the above-mentioned drawbacks of the prior art within the framework of a simple, rational, easy and effective, as well as economical solution.

[0021] In the following description, for simplicity, the term "glaze" refers to an aqueous suspension including transparent and colored enamels or vitrified glazes. In other words, the term "glaze" refers to any aqueous suspension that can be used for surface treatment of ceramic media.

[0022] The decoration process of the ceramic product according to the present invention preferably includes at least one or more of the following stages:

[0023] - providing at least one ceramic medium to be decorated, the at least one ceramic medium having at least one exposed surface and at least one laid surface opposite to each other;

[0024] - applying a water-repellent liquid on the exposed surface according to a predefined design by means of a first printer, preferably a first digital inkjet printer;

[0025] - spreading the aqueous glaze over the entire area of ​​the exposed surface, wherein the spreading is carried out with the aid of a dispensing device;

[0026] - applying a ceramic ink whose design is coordinated with the predefined design on the exposed surface by means of a second printer, preferably a second digital inkjet printer.

[0027] Preferably, the process comprises a firing phase in which the ceramic medium is fired to obtain a decorated ceramic article.

[0028] Preferably, an additional protective glaze may be applied over the entire surface of the ceramic medium prior to firing.

[0029] Preferably, the frit dispensing device comprises an inner hollow container for collecting the frit, the inner hollow container being provided with at least one set of orifices for flowing out the frit.

[0030] Preferably, the dispensing device comprises at least one roller housed in the container and operable in rotation about a relative axis.

[0031] Preferably, the roller is provided with a set of protrusions angularly spaced from one another along the circular development direction of the roller itself, which protrusions are suitable for opening and closing the orifices in a sequential and cyclical manner to respectively allow and prevent the glaze from flowing out of the container.

[0032] Preferably, the glaze spreading is carried out in a single process.

[0033] Preferably, glaze spreading is done using a single color.

[0034] Preferably, the coordinated design is complementary to the predefined design.

[0035] Preferably, the process according to the invention further comprises the stages of generating first electronic data representing the predefined design and processing the result of the first electronic data to obtain second electronic data representing the coordinated design.

[0036] Preferably, the process also comprises an additional stage of spreading at least one ceramic engobole and / or glaze over the entire area of ​​the exposed surface before applying the water-repellent liquid.

[0037] Preferably, the water repellent liquid comprises at least one silicone component.

[0038] An apparatus for decorating ceramic articles according to the present invention preferably comprises at least one or more of the following features:

[0039] - a line of movement of at least one ceramic medium to be decorated along a forward movement direction, wherein the ceramic medium has at least one exposed surface and at least one laid surface opposite to each other;

[0040] - at least one first printer, preferably a first digital inkjet printer, for applying a water-repellent liquid onto the exposed surface according to a predefined design;

[0041] a distribution device for an aqueous glaze, arranged downstream of the first digital printing press in the forward movement direction, for spreading the glaze over the entire area of ​​the exposed surface;

[0042] - at least one second printer, preferably a second digital inkjet printer, arranged downstream of the dispensing device in the forward movement direction and adapted to dispense at least one ceramic ink having a design coordinated with the predefined design on the exposed surface.

[0043] Preferably, the apparatus comprises a kiln for firing the ceramic medium, the kiln being arranged downstream of the second digital printing press in the forward movement direction, in order to obtain a decorated ceramic article.

[0044] Preferably, the apparatus comprises glaze distributing means between the second printing press and the firing kiln for distributing the glaze over the entire surface of the article.

[0045] Preferably, the dispensing device comprises: an internal hollow container for collecting the glaze, the internal hollow container being provided with at least one set of orifices for flowing out the glaze; and at least one roller, which is accommodated in the container and can be rotated around a relevant axis, the roller being provided with a set of protrusions angularly spaced from each other along the circular development direction of the roller itself, and these protrusions are suitable for opening and closing the orifices in a sequential and cyclic manner to allow and prevent the glaze from flowing out of the container, respectively.

[0046] Preferably, the device comprises at least one control and command unit, which is operatively connected to at least a digital printing press and is provided with at least one processing unit, which comprises a first generating mechanism for generating at least one first electronic data representing a predefined design and a second generating mechanism for generating a second electronic data representing a coordinated design.

[0047] Preferably, a first generating mechanism for generating the first electronic data and a second generating mechanism for generating the second electronic data are operatively connected to each other.

[0048] Preferably, the control and command unit comprises a programmable memory operatively connected to the processing unit.

[0049] Preferably, the command and control unit is built into at least one of the digital printing presses. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Other characteristics and advantages of the invention will become more apparent from the description of a preferred but not exclusive embodiment of an apparatus and process for decorating ceramic articles, which is illustrated by way of schematic but non-limiting example in the accompanying drawings, in which:

[0051] - Figure 1 is an axonometric schematic diagram of an apparatus according to the present invention;

[0052] - Figure 2 is a cross-sectional view of a ceramic medium during the application phase of a water repellent liquid according to a process of the present invention;

[0053] - Figure 3 is based on Figure 1 The trajectory line III-III in Figure 2 a cross-sectional view of the ceramic medium after the application stage in;

[0054] - Figure 4 is a cross-sectional view of a ceramic medium during a glaze spreading stage in a process according to the present invention;

[0055] - Figure 5 is based on Figure 1 The trajectory line VV in Figure 4 A cross-sectional view of the ceramic medium after the spreading stage in FIG.

[0056] - Figure 6 is a cross-sectional view of a ceramic medium during the application phase of a ceramic ink according to the process of the present invention; and

[0057] - Figure 7 is based on Figure 1 The trajectory line VII-VII in Figure 6 Cross-sectional view of the ceramic media after the application stage. DETAILED DESCRIPTION

[0058] With particular reference to the drawings, reference numeral 1 generally designates an apparatus for decorating ceramic articles.

[0059] According to a preferred but not exclusive embodiment, the apparatus 1 comprises a line 2 for movement of at least one ceramic medium S to be decorated along a forward movement direction 3, wherein the ceramic medium S has at least one exposed surface "Sa" and at least one laid surface "Sb" opposite to each other, such as Figure 2The moving line 2 defines the support plane for the ceramic medium S and is composed of, for example, a plurality of motorized belts.

[0060] The device 1 then comprises at least one first printer, preferably a first digital inkjet printer 4, schematically shown in the figure, for applying a water-repellent liquid L on the exposed surface "Sa" according to a predefined design identified with reference letter D in the figure.

[0061] The water-repellent liquid L is characterized as having properties that prevent the water-based ceramic engobes and / or glaze from subsequently adhering to the area to which the liquid itself is applied. In other words, in the area where the water-repellent liquid L is applied on the exposed surface "Sa" of the ceramic medium S, the engobes and / or glaze will not adhere to the surface "Sa" itself, and therefore will not overlap with the water-repellent liquid. This non-overlapping results in a difference in thickness between the area to which the water-repellent liquid is applied and the area to which the water-repellent liquid is not applied. At the end of the process described herein, the latter area will have a greater thickness than other areas to which the engobes and / or glaze are not sufficiently adhered.

[0062] More specifically, the water-repellent liquid L comprises at least one silicone component, ie a component consisting of silicone or a mixture of several different silicones.

[0063] Downstream of the first digital printing press 4, in the forward moving direction 3, a dispensing device 5 of a glaze C (usually aqueous) is provided. The dispensing device 5 is suitable for dispensing the glaze C onto the exposed surface "Sa", preferably onto the whole area thereof.

[0064] Preferably, the dispensing device 5 comprises an internal hollow container 6 for supplying the glaze C to at least one set of orifices 7 so as to put the interior of the container 6 in fluid communication with the exterior of the container 6 , allowing the glaze C to flow out.

[0065] Preferably, the dispensing device 5 also comprises at least one roller 8 housed inside the container 6 and capable of operating in rotation about a relative axis x. Suitably, the roller 8 is provided with a set of protrusions 9 angularly spaced from one another along the circular development direction of the roller itself, suitable for opening and closing the orifice 7 in a sequential and cyclical manner, so as to respectively allow and prevent the glaze C from being transferred from the inside of the container 6 to the outside thereof, causing the glaze C to flow out in the form of continuous drops generated through the orifice 7.

[0066] More specifically, the protrusions 9 are angularly spaced from one another along the circular development direction of the roller 8 so as to open and close the orifices 7 in a sequential and cyclical manner during the rotation of the roller itself. Thus, the glaze drops are dispensed through the orifices 7, resulting in a substantially dotted and uniform application on the ceramic medium S. As the opening time of the orifices 7 varies, the size of the dispensed drops also varies. Thus, if the opening time of the orifices 7 increases, the size of the dispensed drops increases. Suitably, the orifices 7 are aligned with one another parallel to the longitudinal development direction of the container 6.

[0067] Then, the dispensing device 5 is adapted to spread a uniform layer of glaze C on the exposed surface "Sa" in a single pass. In other words, a drop of glaze C is dispensed on each area of ​​the exposed surface "Sa", and the ceramic medium S passing once under the dispensing device 5 is completely covered with glaze C.

[0068] The glaze C, once deposited on the exposed surface "Sa", is "repelled" by the water-repellent liquid L, which moves away from the area where it was previously applied and thus accumulates in areas of the exposed surface "Sa" that are not related to the predefined design D. This results in the accumulation of the glaze C in areas of the exposed surface "Sa" outside the predefined design D. This creates a difference in thickness in the areas with the glaze C compared to the areas constituting the same predefined design D. As a result of the application of the glaze C, a texture effect is obtained on the exposed surface "Sa".

[0069] According to the invention, the apparatus 1 comprises at least one second printer, preferably a second digital inkjet printer 10, arranged downstream of the dispensing device 5 along the forward movement direction 3 and adapted to dispense one or more ceramic inks I onto the area of ​​the exposed surface "Sa" according to a design corresponding to a predefined design D.

[0070] However, it cannot be excluded that in alternative embodiments the first digital printer 4 and the second digital printer 10 may coincide with each other and, therefore, the moving line 2 may move the ceramic medium S in the forward moving direction 3 in either way.

[0071] In use, the predefined design D is the result of printing a processed image by the first digital printer 4 , the processed image being electronically derived from a reference image which in turn will be used for printing using the ceramic ink I by the second digital printer 10 .

[0072] Thus, the ceramic ink I is dispensed by the second digital printer 10 according to the predefined design D to which the water-repellent liquid L has been applied. The second digital printer 10 may, for example, dispense the ceramic ink I only on the areas outside the predetermined pattern D (i.e., on the areas complementary thereto), overlapping the relief areas obtained by accumulating the previously deposited glaze C. Alternatively, the second digital printer 10 may dispense a first type of ceramic ink on the areas outside the predefined design D, and a second type of ceramic ink different from the first type on the predetermined pattern itself. In other words, the second digital printer 10 may make a design coordinated with the first digital printer 4.

[0073] However, it cannot be excluded that the second digital printing press 10 can distribute the ceramic ink I over the entire area of ​​the exposed surface "Sa". In this case, the coordinated design then corresponds to the full domain, ie to the entire area of ​​the exposed surface "Sa".

[0074] Preferably, the device 1 comprises at least one control and command unit 11, which is operatively connected at least to the digital printing presses 4 and 10 and is provided with a processing unit 12 of the microprocessor type, which comprises a first generating mechanism 13 for generating at least one first electronic data representative of a predefined design D and a second generating mechanism 14 for generating one second electronic data representative of a coordinated design to be applied to the exposed surface "Sa". The first generating mechanism 13 for generating the first electronic data and the second generating mechanism 14 for generating the second electronic data are operatively connected to each other. Preferably, the second generating mechanism 14 for generating the second electronic data is suitable for processing the first electronic data received from the first generating mechanism 13.

[0075] Suitably, the control and command unit 11 also comprises a programmable memory 15 operatively connected to the processing unit 12 .

[0076] The predefined design D may then be selected from those stored in the programmable memory 15 or randomly defined from time to time by the processing unit 12 .

[0077] More specifically, a first generating mechanism 13 for generating first electronic data is operatively connected to the first digital printing press 4 , and a second generating mechanism 14 for generating second electronic data is operatively connected to the second digital printing press 10 .

[0078] The control and command unit 11 may be built into one or both of the digital printing presses 4 and 10 , or may be remotely connected thereto.

[0079] Suitably, the control and command unit 11 is also operatively connected to the dispensing device 5 so as to adjust the rotation speed of the roller 8 according to the optimal amount of glaze to be spread onto the exposed surface "Sa".

[0080] The device 1 then comprises a kiln 16 for firing the ceramic medium S, which is arranged downstream of the second digital printing press 10 along the forward movement direction 3, in order to obtain a decorated ceramic article M.

[0081] Preferably, downstream of the second printer 10 and before the kiln 16, an additional layer of glaze is applied to the entire surface of the ceramic medium S, which glaze may be applied by an additional dispensing device 5 and / or a bell system and / or an airless system.

[0082] In use, according to a preferred but not exclusive embodiment of the present apparatus 1 , when performing a process according to the invention, the operations are as follows.

[0083] The process covered by the present invention first comprises supplying a ceramic medium S to be decorated, which is provided with an exposed surface "Sa" facing outwards when in use and a laying surface "Sb" opposite to the exposed surface "Sa", which is placed on a reference surface, such as a floor or a wall when in use.

[0084] The ceramic medium S can be of various sizes, i.e., it can be of the tile type and therefore typically characterized by dimensions less than 1 meter (e.g., 30×30 cm, 60×60 cm, etc.) or of the ceramic slab type (i.e., characterized by dimensions that can reach more than 3 meters).

[0085] The ceramic medium S is obtained by shaping, ie by compacting a mass of ceramic powder in a manner known to an engineer skilled in the art. In particular, the ceramic medium as supplied does not include any thickness variations to represent a predefined design and its exposed surface "Sa" is substantially flat.

[0086] According to the invention, the process consists in applying a water-repellent liquid L according to a predefined design D by means of a first digital printing press 4 .

[0087] In a particular embodiment, it is also possible to carry out a stage of spreading at least one ceramic engobole over the entire area of ​​the exposed surface "Sa" before applying the water-repellent liquid L.

[0088] After the application of the water-repellent liquid L, a glaze C is applied over the entire area of ​​the exposed surface “Sa”. Preferably, this stage of spreading the glaze C is carried out with the aid of a dispensing device 5 .

[0089] As described above, the distributing device 5 is suitable for intermittently distributing multiple droplets of glaze C onto the exposed surface "Sa" of the ceramic medium S passing thereunder at a variable frequency depending on the speed of the roller 8 and the size of the protrusions 9, so as to achieve a uniform and uniform spreading of the glaze C on the same exposed surface "Sa".

[0090] Advantageously, the spreading of the glaze C is carried out in a single operation, that is to say, at one time and of a single type and a single colour, preferably light, transparent or white.

[0091] As mentioned before, the term "glaze" also generally includes any aqueous suspension, such as engobes or vitrified glazes.

[0092] Then, the glaze C dispensed by the dispensing device 5 is deposited on the exposed surface "Sa" by first also covering the predefined design D. However, due to the characteristics of the water-repellent liquid L, the glaze C moves away from the area to which the water-repellent liquid itself has been applied (that is, from the predetermined pattern D), thereby accumulating in the area around it. In other words, due to the surface tension of water constituting the glaze C itself, the glaze C dispensed by the dispensing device 5 accumulates on the area not affected by the predefined design D.

[0093] Therefore, as a result of the spreading of the glaze C, there is a difference in thickness, and therefore a difference in height, between the area to which the water-repellent liquid L has been applied and the area where the glaze C has accumulated, which has not been affected by the application. Therefore, it can be seen that the area that was initially not affected by the application of the water-repellent liquid L has a greater height than the area affected by the predefined design D, which therefore produces a shallow relief.

[0094] After the glaze C is spread, the ceramic ink I is applied to the ceramic medium S. Specifically, a design is printed on the exposed surface "Sa" by means of the second digital printer 10, which design should be consistent with the predefined design D. Preferably, the design formed by means of the ceramic ink I will overlap the portion of the exposed surface "Sa" affected by the predefined design D and the portion of the exposed surface "Sa" affected by the glaze C.

[0095] Therefore, the positioning, orientation and application of the image formed by the ceramic ink I printed on the ceramic medium S depends on the geometry and spatial distribution of the predefined design on the exposed surface "Sa". In this way, the shapes in relief on the exposed surface "Sa" will correspond to the shapes and lines of the final tile printing.

[0096] In a particular embodiment, the coordinated design according to which the ceramic ink I is applied can be complementary to the predefined design D, that is to say, the ceramic ink I is applied only in areas of the exposed surface "Sa" outside the predefined design itself, by overlapping with the relief areas obtained by accumulation of the glaze C previously deposited.

[0097] However, in another embodiment, the second digital printing press 10 applies a different type of ceramic ink I to areas outside the predefined design D and to the predefined design itself.

[0098] In more detail, the process according to the invention comprises a phase of providing a reference image selected from a large number of digital images, and then implementing from these digital images sub-phases of generating first electronic data representing a predefined design D and processing the first electronic data to obtain second electronic data representing a coordinated design. The first electronic data and the second electronic data are processed by a first digital printing machine 4 and a second digital printing machine 10, respectively.

[0099] The generation and processing of the first electronic data are performed by the above-mentioned control and command unit 11.

[0100] The process according to the invention may comprise an additional stage of applying an additional glaze layer on the surface of the ceramic medium, which additional glaze layer may be applied by means of an additional dispensing device 5 and / or a bell system and / or an airless system.

[0101] Finally, the process according to the invention comprises a stage of firing the ceramic medium S in order to obtain the decorated ceramic article M.

[0102] The firing stage uses a ceramic kiln of a type known to those skilled in the art (e.g. Figure 1 As shown, indicated by reference numeral 16).

[0103] It has been established in practice that the above-described apparatus and process achieve the intended purposes, with particular emphasis on the fact that the combination of the application of a water-repellent liquid by means of digital printing, the spreading of an aqueous glaze by means of a glaze dispensing device comprising a hollow container in which a roller is rotatably arranged in order to distribute glaze drops for dot-like application to the medium, and the application of a ceramic ink by means of digital printing according to a design coordinated with the previous application of the water-repellent liquid, makes it possible to achieve a textural effect on the exposed surface of the article thus decorated while maintaining a high degree of clarity.

[0104] In particular, spreading a uniform layer of glaze on the exposed surface of the ceramic support to be decorated by means of a single process and according to the method described above allows obtaining high-quality three-dimensional effects. In fact, the amount of glaze is one of the most important factors for obtaining a high-definition surface structure: this is because too little glaze results in the obtained relief being barely perceptible, while too much glaze impairs the water-repellent effect of the liquids and the textural effect is therefore not noticeable.

[0105] In addition, the quality of the three-dimensional effect using relief and bas-relief is most appreciated when combined with high-definition image graphics, which are preferably achieved with a digital printer, more preferably with a printer with a definition level higher than 150 DPI (dots per inch). The method and apparatus make it possible, for example, to faithfully reproduce the shape of the veins of stone, marble or the grain of wood by providing not only a pleasing aesthetic appearance but also a tactile pleasure. This makes the ceramic medium S very similar to the object on which the image is depicted, which is particularly appreciated by the end user.

[0106] Likewise, the development of designs coordinated with predefined designs for applying water repellent liquids can achieve aesthetic effects that are not achievable with heretofore known processes and apparatuses.

Claims

1. A process for decorating ceramic products, characterized in that: The decoration process includes at least the following stages: - providing at least one ceramic medium (S) to be decorated, said at least one ceramic medium to be decorated having at least one exposed surface ("Sa") and at least one laid surface ("Sb") opposite to each other; - applying a water-repellent liquid (L) on said exposed surface ("Sa") according to a predefined design (D), by means of a first printer, preferably a first digital inkjet printer (4); - spreading an aqueous glaze (C) on said exposed surface (Sa), wherein said spreading is carried out with the aid of a distribution device (5), said distribution device comprising: an inner hollow container (6) for collecting the glaze (C), the inner hollow container being provided with at least one set of orifices (7) for flowing out the glaze (C), and at least one roller (8) housed in the container (6) and operable in rotation about a relative axis (X), the roller (8) being provided with a set of protrusions (9) spaced angularly from one another along the circumferential development direction of the roller itself, the protrusions being suitable for opening and closing the orifices (7) in a sequential and cyclical manner, so as to respectively allow and prevent the glaze (C) from flowing out of the container (6); - applying on said exposed surface (Sa) by means of a second printer, preferably a second digital inkjet printer (10), at least one ceramic ink having a design coordinated with said predefined design (D).

2. The process according to claim 1, characterized in that The process comprises at least one stage of firing the ceramic medium (S) after applying at least one ceramic ink in order to obtain a decorated ceramic article (M).

3. The process according to claim 1 or 2, characterized in that The spreading is performed in a single process step.

4. Process according to one or more of the preceding claims, characterized in that The spreading is performed using a single color.

5. Process according to one or more of the preceding claims, characterized in that The coordinated design is complementary to the predefined design (D).

6. Process according to one or more of the preceding claims, characterized in that The process further The following phases are included: - generating first electronic data (D) representing said predefined design; - Processing the result of said first electronic data to obtain second electronic data representing said coordinated design.

7. Process according to one or more of the preceding claims, characterized in that Said process comprises a stage of spreading at least one layer of ceramic engobole over the entire area of ​​said exposed surface (Sa) before said applying said water-repellent liquid (L).

8. Process according to one or more of the preceding claims, characterized in that The water-repellent liquid (L) comprises at least one silicone component.

9. A device (1) for decorating ceramic products, characterized in that The device comprises: - a moving line (2) of at least one ceramic medium (S) for decoration along a forward moving direction (3), wherein said ceramic medium (S) has at least one exposed surface (Sa) and at least one laid surface ("Sb") opposite to each other; - at least one first digital inkjet printer (4) for applying a water-repellent liquid (L) onto said exposed surface (Sa) according to a predefined design (D); a distribution device (5) for an aqueous glaze (C), arranged downstream of the first digital printing machine (4) along the forward movement direction (3), for spreading the glaze (C) on the exposed surface (Sa), and comprising: an inner hollow container (6) for collecting the glaze (C), the inner hollow container being provided with at least one set of orifices (7) for flowing out the glaze (C), and at least one roller (8) housed in the container (6) and operable in rotation about a relative axis (X), the roller (8) being provided with a set of protrusions (9) spaced angularly from one another along the circumferential development direction of the roller itself, the protrusions being suitable for opening and closing the orifices (7) in a sequential and cyclical manner, so as to respectively allow and prevent the glaze (C) from flowing out of the container (6); - at least one second digital inkjet printer (10) arranged downstream of said dispensing device (5) along said forward movement direction (3) and suitable for dispensing at least one ceramic ink (C) whose design is coordinated with said predefined design (D) on said exposed surface (Sa).

10. The device according to claim 9, characterized in that The device comprises at least one kiln (16) for firing the ceramic medium (S), the kiln being arranged downstream of the second digital printing press along the forward movement direction (3) to obtain a decorated ceramic article (M).

11. The device (1) according to claim 9 or 10, characterized in that The device comprises at least one control and command unit (11), which is operatively connected to at least one digital printing machine (4, 10) and is provided with at least one processing unit (12), which comprises a first generating mechanism (13) for generating at least one first electronic data representing the predefined design (D) and a second generating mechanism (14) for generating second electronic data representing the coordinated design.

12. The device (1) according to claim 11, characterized in that The first generating mechanism (13) for generating the first electronic data and the second generating mechanism (14) for generating the second electronic data are operatively connected to each other.

13. The device (1) according to claim 11 or 12, characterized in that The control and command unit (11) comprises a programmable memory (15) operatively connected to the processing unit (12).

14. Device (1) according to one or more of claims 11 to 13, characterized in that The control and command unit (11) is built into at least one of the digital printing presses (4, 10).

Images