IT202100024287A1 - Ceramic tile and method of producing ceramic tiles - Google Patents

Description

DESCRIPTION

of the Italian Patent for Industrial Invention entitled:

?Ceramic tile and method of producing ceramic tile?

TECHNICAL FIELD

The present invention relates to a method for making ceramic tiles and ceramic tiles, in particular floor or wall tiles.

PRE-EXISTING TECHNIQUE

Usually, ceramic tiles comprise a substantially sheet-like body of ceramic material having a decorative surface, which can be be glazed or unglazed. The decorative surface can be equipped with a decoration represented, for example, an imitation of a wood, a natural stone, a marble, a concrete, a resin or any other decoration. The decorative surface of the tile can further comprising a relief structure for example representing the veining of a stone or wood.

The relief structure is created by pressing during the formation of the tile. In practice, the powders constituting the ceramic mixture are loaded into a mold and pressed by means of a punch having a structure corresponding to the negative of the relief structure of the tile. The pressing can also take place in a continuous process, or in any case without a mould, in which the negative structure is? reported on a compacting belt.

The necessity? to use punches, or otherwise preformed negatives, limits the variability? of the achievable relief structures. Consequently, the products obtained often have an evidently artificial appearance mainly due to the high repetition of the reliefs and printed decorations.

Furthermore, in order to allow installation with reduced joints, or even in contact, the ceramic tiles are rectified after firing so as to have a substantially regular size. However, the grinding operation involves a relatively high cost due to the production of waste and the consumption of abrasive material.

In order to reduce the artificial appearance of the ceramic product, WO2019116132 proposes a method which provides for an irregular mechanical processing of the edges of a tile before the decoration phase.

First of all, the present invention proposes to provide an alternative method for manufacturing ceramic tiles, which, in accordance with some of its embodiments, is directed to solve one or more? of the problems deriving from the state of the art.

EXHIBITION OF THE INVENTION

The present invention, in accordance with a first independent aspect thereof, proposes a tile provided with a lower face and an upper face and comprising a ceramic support and a decoration of at least said upper face.

This tile can present the characteristic that said lower face differs in shape and/or size from said upper face, in particular the perimeters of said upper face and said lower face can be different in shape.

This tile can have the characteristic that said lower face has sides substantially at right angles to each other. In this way the tiles can be placed side by side with reduced joints and preferably in contact with each other at the sides of the lower face. Preferably, said sides of the lower face are not ground. By substantially squared it is meant that the angles between the sides of the lower face are substantially equal to each other. In particular, with ?basically? it is understood that said angles can differ from each other by less than 2?, preferably by less than 1?.

According to the preferred embodiment of the invention, the upper face of the tile has sides that are not square to each other. By out of square we mean that at least one of the angles between the sides of the upper face differs from the other angles, preferably all the angles differ from each other. In particular, said angles of the upper face can differ from each other by at least 1?, preferably by at least 2?. In this way, the tiles can be placed side by side, even in contact, but the joints between the upper faces of the tiles will be different from each other, giving the tiled surface a less artificial appearance. Each tile itself will result? also less artificial.

The tile support can include walls with a substantially vertical development, whereby vertical is meant perpendicular to the plane of the lower and upper faces. It should be noted that said upper and lower faces can preferably be parallel to each other. At least one of these walls with vertical development can? present an inclination with respect to the horizontal plane, or with respect to the plane of the lower face, different from the inclination of the other walls. Preferably, the slope of each wall differs from the others. It should be noted that the walls comprise an upper edge coinciding with the respective side of the upper face, and a lower edge coinciding with a respective side of the lower face. In this way, the upper face has a different plan shape, at least in size, than the lower face, giving the tile an irregular and less artificial appearance.

In the preferred embodiment, at least one, preferably each, of the vertically extending walls has a variable inclination along a longitudinal direction of the wall itself. Note that said longitudinal direction ? preferably parallel to the plane of the underside. In this way, the upper edge of the said wall can? form different angles the incident walls at the ends? opposite. According to some embodiments said walls can be curved.

Preferably, the sides of the upper surface are not ground. In particular, ? it is preferable that the walls of the tile are not rectified and/or worked with a machine tool. The tile can comprise substantially any shape, preferably a polygonal shape. Preferred examples of said shapes can be rectangles, squares or hexagons. According to the preferred embodiment, the tile can present a maximum size, i.e. a length of its longer side of less than 35cm, preferably less than 30cm, even more? preferably less than 25cm. Indeed, the inventors have surprisingly found that limiting the size of the tile below said values? Is it possible to limit shape defects that may occur in cooking so? that the rectification of the sides of the lower face is not necessary, and more? in general of the walls of the tile. The tile can moreover, have a thickness of between 2 and 15 mm, preferably between 4 and 12 mm.

According to the preferred embodiment, the ceramic support can be made of porcelain stoneware. According to other embodiments, the support pu? be made of other materials such as monoporosa, red stoneware, single-fired red body, clinker or terracotta. The tile can preferably comprising a surface coating, preferably at least an enamel, suitable for at least partially covering an upper surface of the support.

The surface coating can include a base coating suitable for defining a base for the decoration or for constituting the decoration itself. In this way, the bottom layer can cover the color of the support as well as? waterproof the substrate itself. Preferably, the ground layer can include at least one glaze and/or one engobe. The bottom layer can present any color, however ? it is preferable that the color of the base layer be selected so as to decrease the quantity of pigment to form the decoration. The decorum? preferably made in the surface coating, for example pu? be formed into a decorative layer placed on top of the ground layer. Preferably the decoration? made up of pigments printed according to a digital design. The decoration can present any type of imaginative design or imitating an artificial or natural material. According to the preferred embodiment, the decoration comprises characteristics representing defects and/or imperfections such as scratches, rust, variations in colour? etc.

The surface coating can comprising an upper layer arranged above the decoration and/or the base layer. Preferably, said upper layer can be able to protect the decoration itself from wear. In this case, advantageously, the upper layer can? be transparent or translucent so as to reveal the underlying decoration. According to other embodiments, the upper layer can include fillers and/or additives capable of conferring new functions? and/or improve the properties? surface of the decorative layer, such as properties? anti-wear, anti-slip, antibacterial or anti-stain. The top layer can be configured to give particular aesthetic characteristics to the tile, such as lustres, metallic effects, variations in gloss? etc. The top layer can include a glaze or grit. In the preferred embodiment, the bottom layer and/or the top layer has a thickness greater than 100 microns, preferably greater than 200 microns, even more so. preferably greater than 500 microns.

The tile can comprises at least one relief structure in said upper face. This relief structure can comprising a first structure formed in the surface coating. Advantageously, said first structure can? be made at least in the upper layer of the surface coating, in this way the conformation of said first structure is not? altered by the overlapping of other layers and is visible so? as made with high definition. Furthermore, being made in the upper layer, above the decoration, the first structure can present characteristics corresponding to characteristics of the decoration so? to create a synergistic effect between structure and decoration, for example by giving greater depth? to the decoration and/or contrasting and/or amplifying light reflection effects in correspondence with certain portions of the decoration. According to a preferred embodiment, said first structure can be configured to mimic defects such as scratches, bubbles, nicks or roughness. Preferably said first structure can? be composed of depressions or cavities? in the upper face of the tile, for example the said upper layer can? be capable of partially or non-homogeneously covering the upper surface of the support, so that where the structure is not? present or ? present in lesser quantity? a gap or cavity forms. Preferably, said rhyme structure can? be made according to a digital design, preferably called digital design ? coordinated with the decor. In some embodiments, the first structure could be made partially or entirely in the bottom layer. ? It is possible that in some embodiments the first structure is made partially in the bottom layer and partially in the top layer. This relief structure can comprising a second structure formed in the support. Note that the relief structure can? understand both the first and the second structure or even just one of the two. The second structure? preferably made by pressing in the support and ? then formed by concavit? and/or depressions. However, according to other embodiments, the second structure can? be made using additive techniques in which part of the material forming the support is deposited on the upper surface of the support according to a predefined pattern. Preferably, the second structure has a greater depth? compared to the first structure. Furthermore, preferably said second structure can? present more features coarse of the structure in relief while the first structure can? understand more detailed features of the relief structure. For example, the second structure can? present depressions able to make the upper surface of the support wavy, in this way areas are obtained on the surface of the tile with different reflection of the light, giving the tile an irregular and less industrial appearance. In order to increase the impression of craftsmanship? of the tile? preferable that the second structure is not coordinated with the drawing, however according to other embodiments? It is possible that the second structure includes characteristics corresponding to characteristics of the decoration.

A second independent aspect of the invention relates to a set of tiles in which one or more of the tiles are in accordance with the first independent aspect. Said tiles can comprise one or more? of the tiles according to the first independent aspect. According to the preferred embodiment of said second independent aspect, the lower faces of the tiles of the set have the same shape and/or size. Preferably the sides of said lower faces are at right angles to each other. Furthermore, according to the preferred embodiment of said second independent aspect, the upper faces of the tiles of the set can have different shapes and/or sizes. Preferably the sides of said upper faces are not at right angles to each other.

because the tiles can be installed with the sides of the lower face in contact with them, the installation itself is noticeably smoother. faster than traditional installation as it is not necessary to use spreaders or spacers. Furthermore, the different shape and/or size of the upper faces causes a joint, or a space, to be created between the edges of the tiles suitable for receiving a grout for waterproofing the tiled surface. Furthermore, the variability of the upper faces gives a substantially handcrafted appearance to the tiled surface.

A third independent aspect of the invention provides a method for the production of ceramic tiles, in which said tiles comprise a lower face and an upper face, which comprises the steps of i: preparing a body for ceramic materials; forming said mixture into a sheet-like support to obtain an unfired tile; prepare a decoration of the raw tile; firing said unfired tile to obtain the ceramic tile. The method can have the characteristic that in said forming step, the tile is formed with a lower face which differs from the upper face in shape and/or size. Preferably, the upper face has a different shape from the lower face. Preferably, the lower face has sides at right angles to each other, while the upper face has sides that are out of square. Note that the third independent aspect method ? suitable for producing tiles according to the first independent aspect. The tiles obtained with the method according to the second independent aspect can comprise one or more? of the characteristics described according to the first independent aspect. Said mixture for ceramic materials ? suitable for obtaining, after firing, a tile in ceramic material such as porcelain stoneware, monoporosa, white or red body ceramic, majolica, terracotta. The mixture comprises a mixture of raw material powders such as, for example, clays, kaolin, feldspars, quartz, oxides and other minerals. According to the method in accordance with the invention, the support can be formed by compacting the dough by means of continuous compaction and/or discontinuous pressing. In less preferred embodiments, the possibility that the raw tile can be obtained by extrusion is not excluded. Preferably, the compaction of the dough? obtained with molds and/or compaction belts comprising a negative structure with respect to the design of the second structure so as to form said second structure in the upper surface of the support.

In other embodiments the support pu? be made using molds or flat tapes and the second structure can? be achieved by controlled removal or deposition of part of the mixture on or from the upper surface of the support. For example, the first structure can? be made by means of a first step of printing, preferably digital, of a liquid substance, for example a glue, on the upper surface of the support according to a predefined pattern and subsequent spreading of mixture on the upper surface. Subsequently, the portion of dough which does not adhere to the glue is removed for example by suction means. The remaining portion of dough forms a relief on the upper surface of the support.

In the preferred embodiment, the forming step ? made in a static press in which the dough is compacted inside a mould. Said mold comprises at least one upper wall and one lower wall able to form the respective surfaces of the support. The mold also comprises a plurality side walls designed to contain the dough inside the mold during pressing. Said side walls are shaped to define the shape of the sides of the upper and lower surfaces of the support and of the vertically extending walls of the support itself.

The method can include a drying phase to eliminate at least part of any moisture from the mix? residual, and give the unfired tile greater mechanical strength. Drying? preferably conducted at temperatures higher than 80°C, for example higher than 100°C. Drying? conducted after the pressing phase and, preferably, pu? be conducted prior to the stage of forming the structure. Preferably, the raw tile after drying has a humidity residual less than 8% for example less than 5%.

The method can further comprising a step of applying the base layer, for example a glaze and/or an engobe, on the upper surface of the support. For example, the bottom layer can be applied wet, for example in cascade or by airbrushing so as to deposit a substantially homogeneous layer on the upper surface of the support. However, it is not excluded that the primer layer may be applied by other techniques, for example by means of digital printing, screen printing or flexography or by means of dry application techniques.

Preferably the decoration? preferably printed by digital printing, for example inkjet, even if other printing techniques, such as silk-screen, flexographic, offset, gravure printing are not excluded. However, inkjet printing and non-contact printing techniques in general are preferred because? allow you to apply the decoration on even very pronounced structures.

Advantageously, the method can furthermore comprise a step of applying the upper layer to the upper surface of the support, for example an enamel or a grit. In particular, according to the preferred embodiment of the invention, the upper layer can be applied after the application of the said decoration. Advantageously, the protective layer can? be transparent or translucent. In some embodiments, the top layer may be applied wet, for example in cascade or by airbrushing so as to deposit a substantially homogeneous layer on the upper surface of the tile. However, in the preferred embodiment, the protective layer is applied by means of dry application techniques. In particular, in the preferred embodiment, the upper layer is applied through a first step of printing, preferably digital, of a liquid substance, for example a glue, on the upper surface of the support according to a predefined pattern, and a subsequent spreading of grit on said upper surface. Subsequently, the portion of grit which does not adhere to the glue is removed for example by suction means. The remaining portion of grit forms a relief in the upper layer making the first structure. The first structure can be made in the same way also in the bottom layer.

The method further comprises the step of firing the tile at a temperature higher than 900°C, preferably higher than 1000°C, for example about 1200°C. The cooking stage? subsequent to the construction phase of the structure and, preferably ? subsequent to the application phases of the primer and protective coatings and of the decoration in order to fire the support and coatings together.

According to the preferred embodiment of the invention, the method does not provide for a step of squaring or grinding the tiles.

Preferably, for each production batch, the method can be configured to produce a set of tiles in which the bottom faces of said tiles have the same shape. Preferably for each production lot said method can? be configured to produce a set of tiles where the tiles have different top faces. Preferably, in each production batch at least 4 different shapes of the upper face can be identified, preferably at least 8 different shapes. Preferably, in each production batch at least 4 different first structures can be identified, preferably at least 8 first structures. Preferably, in each production batch at least 4 different decorations can be identified, preferably at least 8 decorations, even more? preferably at least 12 different decors. Preferably, in each production batch at least 4 different second structures can be identified, preferably at least 8 second structures, even more? preferably at least 12 second structures. Preferably the combination of the shape of the upper face, first structure, decoration and/or second structure can be random so as to generate a large number of combinations which helps to give the product a greater impression of craftsmanship, especially after laying the tiles.

Further characteristics and advantages of the invention will become evident from reading the following examples provided by way of non-limiting example, with the aid of the figures illustrated in the enclosed tables.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 ? an isometric view of a tile according to a first aspect of the invention;

Figure 2 ? a top view of a tile according to the first aspect of the invention; Figure 3 ? an enlargement of the section according to the plane III-III of figure 1;

Figure 4 ? an enlargement of area IV of figure 5;

Figure 5 ? a top view of a set of tiles in accordance with the first aspect of the invention.

Figure 6 schematically shows a production line and some steps of a method according to a further aspect of the invention.

BEST WAY TO CARRY OUT THE INVENTION

Figure 1 shows a ceramic tile 1 comprising a body 2 made of ceramic material, for example porcelain stoneware. The tile 1 comprises an upper face 3 provided with a decoration 4, for example representing a wood or a stone. The tile 1 also comprises a lower face 5 opposite the upper face 3 and substantially vertical walls 6.

Figure 2 ? a top view of a tile 1 according to the first aspect of the invention. In figure 2 it can be seen that the lower face 5 of the tile 1 comprises sides 7, defining the lower edges of the vertically extending walls 6, which are at right angles to each other and define a substantially rectangular shape of the lower face 5. It should be noted that in context of the present invention, with ?vertical development? it is understood that the walls 6 develop along a direction incident to the plane of the lower face 5.

In figure 2 it can also be seen that the upper face 3 of the tile 1 comprises sides 8, defining the upper edges of the vertically extending walls 6, which are at right angles to each other and define a polygonal shape, preferably irregular, of the upper face 3. As can be seen from figure 2, the lower face 5 and the upper face 3 have a different shape.

From figure 2 it can also be seen that the vertically extending walls 6 vary their inclination with respect to the horizontal plane, ie with respect to the plane of the lower face 5, along their own longitudinal direction, where said longitudinal direction ? substantially parallel to the plane of the lower face 5.

Figure 2 also shows that the tile comprises a maximum dimension L of less than 35cm, preferably less than 30cm, even more preferably less than 25cm. Figure 3 the tile 1 comprises a relief structure 5 obtained in said body 2 and appears in the upper surface 3. The relief structure 5 can? represent the grain of a wood or a natural stone and can? include structural features, such as recesses or protrusions, corresponding to characteristics of the decoration 4.

Figure 3 shows that the tile 1 also comprises a raised structure 9 formed in the upper face 3. The tile 1 also comprises a surface coating 10 which covers an upper surface 11 of the support 2.

Figure 4 shows that the surface coating 10 comprises a base layer 12, a decorative layer 13 and a top layer 14.

In the preferred example, the base layer 13 comprises a glaze having a substantially uniform color and capable of acting as a background or base for the decoration. In the example the bottom layer 13 ? distributed substantially uniformly on the upper surface 11 of the support 2.

The decorative layer 13 comprises the decoration 4 and ? preferably obtained by digital printing.

The upper layer 14, in the example, comprises a transparent glaze and is placed above the decorative layer 13. In the illustrated example, the upper layer 14 covers the upper surface 11 of the support 2 in a non-uniform manner. In the example discontinuity? of the upper layer 14 are represented by gaps 15. The alternation between the upper layer 14 and the gaps 15 creates a first structure 16 of the relief structure 9.

A second structure 17 of the raised structure 9 ? made in the support 2, for example by pressing. In the preferred example illustrated, the second structure 17 comprises depressions more? large and less defined than the first structure 16 which ? able to define detailed aspects of the structure in relief 9.

Figure 5 shows a top view of a set 20 of tiles 1 as illustrated in figures 1 to 4, in which said tiles 1 comprise a lower face 5 substantially having the same shape and size so that they can be laid side by side however the upper faces 3 have a different shape and size. In particular, the? irregularity? of the shapes of said upper faces 3 creates joints 21 between the tiles having variable dimensions, increasing the impression of craftsmanship? of Sep 20.

Figure 6 shows some steps of a method for making the tile 1 of figure 1, in accordance with a further independent aspect of the invention.

The method comprises a step S1 of forming an unfired tile 22, in this step substantially defined by the support 2, by compacting powders of a ceramic body. In practice, in a compacting station 25 the powders are compacted, in the example by means of a discontinuous press, so as to give the body 2 a substantially sheet-like shape. Preferably the press uses a mold 23 shaped to give the upper surface 11 of the support 2 the second structure 17 as well as? to define the shapes of the upper 3 and lower 5 faces of the tiles 1. The compacting station ? preferably configured to make at least 4, preferably 8 different shapes of the upper faces 3 for each production batch. The compaction station ? preferably configured to make at least 4, preferably 8 different second structures 17 for each production batch.

The support 2 advances along the line in an advance direction D towards a dryer 26 for the removal of moisture. from the dough of the body 2 in a drying step S2.

Subsequently, the dried body 2 advances towards a coating station 27 in which, by means of a coating passage S3, the raw tile 22 is provided with the base layer 12, for example by means of airless spraying or airbrushing. The coated green tile 22 advances towards a decoration station 28 equipped with an inkjet printer 29 in which the green tile 22 is provided with the decoration 4 by means of a printing step S4.

The green tile 22, now decorated, advances towards a second coating station 30 where, by means of a second coating passage S5, the green tile 22 is provided with the upper layer 14.

In the illustrated example, the second coating station 30 comprises an inkjet printer 31 suitable for printing a glue according to a predefined pattern, and a distribution device 32 suitable for spreading a grit, or a dry glaze, on the upper surface of the support 2 in so that a part of said grit adheres to the glue according to the drawing. The second coating station 30 also comprises a removal device 33, for example an aspirator, able to remove the excess grit not adhered to the glue, thus generating the gaps 15 in the upper layer 14.

Subsequently the raw tile 9 ? subjected to a firing step S6 in a kiln 34, for example a continuous roller kiln at a maximum temperature of approximately 1200?C so as to obtain tile 1.

Note that the method ? free from grinding or squaring steps after firing.

The invention so? conceived ? susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept.

Furthermore, all the details can be replaced by other technically equivalent elements. In practice, the materials used, as well as? the contingent shapes and dimensions may be any according to requirements without thereby departing from the scope of protection of the following claims

Also, how? clear from the content of the description, the present invention ? relating to one or more of the articles listed below and numbered from 1 to 48:

1.- A tile having a lower face and an upper face and comprising a ceramic support and a decoration on at least said upper face.

2.- Tile according to article 1, wherein said lower face differs in shape and/or size from said upper face, in particular the perimeters of said upper face and said lower face can be different in shape.

3.- Tile according to article 1 or 2, in which said lower face has sides substantially at right angles to each other, preferably said sides of the lower face are not rectified.

4.- Tile according to any one of the preceding articles, in which the upper face of the tile has sides that are out of square with each other.

5.- Tile according to any one of the preceding articles, in which the support of the tile comprises substantially vertical walls, preferably at least one of said vertical walls has an inclination with respect to the horizontal plane, or with respect to the plane of the lower face, different from the inclination of the other walls, even more? preferably in which the inclination of each wall differs from the others. 6.- Tile according to article 5, wherein the walls comprise an upper edge coinciding with the respective side of the upper face, and a lower edge coinciding with a respective side of the lower face.

7.- Tile according to article 5 or 6, in which at least one, preferably each, of the vertically extending walls has a variable inclination along a longitudinal direction of the wall itself.

8.- Tile according to any one of articles 5 to 7, in which the sides of the upper surface are not ground, in particular, ? it is preferable that the walls of the tile are not rectified and/or worked with a machine tool.

9.- Tile according to any of the previous articles, where the tile can? comprise substantially any shape, preferably a polygonal shape, preferred examples of said shapes can be rectangles, squares or hexagons.

10.- Tile according to any one of the preceding articles, having a maximum dimension, i.e. a length of its longest side of less than 35cm, preferably less than 30cm, even more? preferably less than 25cm.

11.- Tile according to any one of the preceding articles, having a thickness ranging from 2 to 15 mm, preferably ranging from 4 to 12 mm.

12.- Tile according to any of the previous articles, where the ceramic support? be made of porcelain stoneware.

13.- Tile according to any one of the preceding articles, comprising a surface coating, preferably at least one glaze, capable of covering at least partially an upper surface of the support.

14.- Tile according to article 13, wherein the surface coating comprises at least one base layer, preferably the base layer has a color selected so as to reduce the quantity of pigment to form the decoration.

15.- Tile according to article 13 or 14, where the decoration is preferably made in the surface coating, preferably in which the decoration is formed into a decorative layer placed on top of the ground layer.

16.- Tile according to any of the previous articles, where the decoration is? made up of pigments printed according to a digital design.

17.- Tile according to any of the preceding articles, in which the decoration includes characteristics representing defects and/or imperfections such as scratches, rust, variations in tone.

18.- Tile according to any one of the articles from 13 to 17, wherein the surface coating comprises an upper layer arranged over the decoration and/or the base layer, preferably said upper layer ? be able to protect the decoration itself from wear.

19.- Tile according to article 18, where the upper layer is transparent or translucent.

20.- Tile according to article 18 or 19, in which the base layer and/or the upper layer has a thickness greater than 100 microns, preferably greater than 200 microns, even more? preferably greater than 500 microns.

21.- Tile according to any one of the preceding articles, comprising at least one structure in relief in said upper face.

22.- Tile according to article 21, in which said relief structure can include a first structure formed in the surface coating, preferably said first structure ? made at least in the upper layer of the surface coating.

23.- Tile according to article 22, in which the first structure has characteristics corresponding to the characteristics of the decoration.

24.- Tile according to article 22 or 23, in which said first structure can? be configured to mimic defects such as scratches, bubbles, nicks or roughness.

25.- Tile according to any of the articles from 22 to 24, in which said first structure ? composed of depressions or cavities? in the upper face of the tile, for example the said upper layer ? capable of partially or non-homogeneously covering the upper surface of the support.

26.- Tile according to any of the articles from 21 to 25, in which said relief structure can? comprising a second structure formed in the support.

27.- Tile according to article 26, where the second structure ? preferably made by means of pressing into the support, for example ? formed by concavity? and/or depressions.

28.- Tile according to article 26 or 27, in which the second structure has more characteristics? coarse of the structure in relief while the first structure can? understand more detailed features of the relief structure.

29.- Tile according to any one of the articles from 26 to 28, in which the second structure has depressions able to make the upper surface of the support undulating.

30.- Tile according to any of the articles from 26 to 29, wherein said second structure is not coordinated with the design.

31.- A set of tiles in which one or more? of the tiles are in accordance with any of the previous articles.

32.- Set according to article 31, in which the lower faces of the tiles of the set have the same shape and/or size.

33.- Set according to article 31 or 32, in which the sides of said lower faces are at right angles to each other.

34.- Sets according to any one of the articles from 31 to 33, wherein the upper faces of the tiles of the set can have different shapes and/or dimensions.

35.- Set according to any of the articles from 31 to 34, in which the sides of said upper faces are not at right angles to each other.

36.- A method for the production of ceramic tiles, in which said tiles comprise a lower face and an upper face, which includes the steps of:

prepare a mixture for ceramic materials;

forming said mixture into a sheet-like support to obtain an unfired tile; prepare a decoration of the raw tile;

firing said unfired tile to obtain the ceramic tile.

37.- The method according to article 36, having the characteristic that in said forming phase, the tile is formed with a lower face which differs from the upper face in shape and/or size, and/or in which the upper face has a different shape from the lower face, and/or in which the lower face has sides that are square to each other, while the upper face has sides that are out of square.

38.- The method according to article 36 or 37, in which said tile has ? in accordance with any of the articles from 1 to 30.

39.- The method according to one of the articles from 36 or 38, in which the support ? formed by compacting the dough through continuous compaction and/or discontinuous pressing.

40.- The method according to article 39, in which the forming step ? made in a static press in which the dough is compacted inside a mould.

41.- The method according to article 40, in which said mold comprises at least one upper wall and one lower wall adapted to form the respective surfaces of the support and a plurality of side walls suitable for containing the dough inside the mold during pressing and in which said side walls are shaped to define the shape of the sides of the upper and lower surfaces of the support and of the vertically extending walls of the support itself.

42.- The method according to one of articles 36 or 41, which includes a drying phase to eliminate at least part of any moisture from the mix? residual, and give the unfired tile greater mechanical strength.

43.- The method according to one of articles 36 or 42, which comprises a step of applying the base layer, for example a glaze and/or an engobe, on the upper surface of the support.

44.- The method according to one of articles 36 or 43, in which decorum is printed preferably by digital printing, for example inkjet.

45.- The method according to one of the articles 36 or 44, comprising a step of applying the upper layer on the upper surface of the support, for example an enamel or a grit.

46.- The method according to article 45, in which the upper layer is applied by means of dry application techniques.

47.- The method according to article 46, in which the upper layer is applied through a first printing step, preferably digital, of a liquid substance, for example a glue, on the upper surface of the support according to a predefined design, and a subsequent spreading of grit on said upper surface. Subsequently, the portion of grit which does not adhere to the glue is removed for example by suction means.

48.- The method according to one of articles 36 or 47, which does not include a step of squaring or rectifying the tiles.

Claims (10)

1.- A tile (1) provided with a lower face (5) and an upper face (3), and comprising a ceramic support (2) and a decoration (4) of at least said upper face (3) in which said face bottom (5) differs in shape and/or size from said top face (3). 2.- Tile (1) according to Claim 1, wherein said lower face (5) has sides (7) substantially at right angles to each other, preferably said sides (7) of the lower face (5) are not rectified. 3.- Tile (1) according to claim 1 or 2, in which the upper face (3) has sides (8) which are out of square with each other. 4.- Tile (1) according to any one of the preceding claims, wherein the support (2) comprises substantially vertical walls (6) and wherein at least one of said vertical walls (6) has an inclination with respect to the horizontal plane, i.e. with respect to the plane of the lower face (5), different from the inclination of the other walls (6), preferably in which the inclination of each wall (6) differs from the others. 5.- Tile (1) according to claim 4, in which at least one, preferably each, of the vertically extending walls (6) has a variable inclination along a longitudinal direction of the wall itself. 6.- Tile (1) according to any one of the preceding claims, having a maximum dimension (L) of less than 35cm, preferably less than 30cm, even more? preferably less than 25cm. 7.- Tile (1) according to any one of the preceding claims, comprising a surface coating (10) which covers an upper surface (13) of the support (2). 8.- Tile (1) according to any one of the preceding claims, comprising a relief structure (9) in said upper face (3), and in which said relief structure (9) comprises a first structure (16) able to define detailed aspects of the structure in relief (9) and a second structure (17) able to define more? coarse relief structure (9) 9.- Tile (1) according to claim 1, and in which said first structure (16) is obtained by means of a digital technique, and in which said second structure (17) ? obtained by pressing. 10.- A set of tiles (1) in which one or more? of the tiles (1) of the set are in accordance with any one of the preceding claims and wherein the lower faces (5) of the tiles (1) of the set have the same shape and/or size.