ITBO20110694A1 - PLANT AND METHOD FOR THE PRODUCTION OF CONCRETE COCKS OR TILES - Google Patents

Description

DESCRIPTION

PLANT AND METHOD FOR THE PRODUCTION OF CEMENT COUPLES OR TILES.

The present invention relates to a plant and a process for the production of concrete roof tiles or roof tiles.

The present invention finds particular application in the construction industry, and more precisely in the realization of elements for roofs or roofs.

In the known art, numerous machines are known, called â € œgoliereâ €, capable of making a succession of concrete tiles or tiles starting from a combined mixture of cement and sand.

For descriptive simplicity, in the text we will refer from now on to the production of tiles only without however losing in generality, since everything related to tiles is equally applicable to tiles.

Known tiling pans are provided with a plurality of operating stations arranged in succession and connected to each other by means of suitable handling means, such as for example conveyor belts.

More precisely, the first operating station is that of forming, in which the tile is made starting from the original mixture.

Typically, the mixture is obtained by mixing a limited quantity of cement with a high quantity of sand, with a variable granulometric curve up to 3-4 mm.

In the known art, the forming station operates by means of pressure extrusion and therefore comprises at least one die defining an extrusion matrix in which each tile is made.

Immediately downstream of the forming station, known tiling pans have a grouting machine.

This grouting machine is configured to make a grout on the extrados (the external surface) of the tile.

The grout is a substantially fluid mixture of cement (and quartz silica) which is used for the external coating of the tile in order to improve the surface finish and filling any extrusion gaps that are created during forming. As soon as it comes out of the grout machine, the tile enters a coloring station, in which one or more brushes covered with a coloring substance rotate at high speed to splash the upper surface of the tile in order to reproduce the typical stripes of the shade caused by aging. in terracotta tiles.

Disadvantageously, the use of rollers or brushes makes the application of the coloring substance not very precise as its distribution is not very homogeneous and characterized by the presence of drops isolated from the rest of the â € œstripâ €.

Downstream of the coloring, the pan provides for the presence of a drying station, in which the tiles are stored and left to mature for a predetermined time interval in a humid environment, at about 40 °.

Upon leaving the drying station, the tiles are taken to a finishing and / or packaging station and then stored in special storage areas awaiting transport to the construction site and their installation.

Disadvantageously, the known systems and methods do not allow to obtain bent or roof tiles in cement similar to those in terracotta, in which the aging effect is also comparable to them.

Furthermore, the presence of the grouting machine standardizes the quality of the tile making its surface independent of the mixture with which it is made.

Disadvantageously, if this can be useful in the presence of coarse mixtures with low dosages of cement, on the contrary it is not very convenient if the basic mixture with which the tile is made has a rather fine grain size.

Note that some implants currently on the market provide for the use of the â € œstretchingâ €.

This solution is carried out on a tile with a fairly smooth surface by incorporating cement slurry or iron oxide pigment only in the mixture, then extruded, which generally generate rather marked strips already in the extrusion phase.

Disadvantageously, with this technology it is not possible to obtain shades, multicolored roofs and therefore strongly shaded roofs recalling roofs aged by time. On the contrary, the roofs resulting from this technology have a homogeneous and repetitive coloring, with rather marked and artificial colors. The purpose of the present invention is to make available a plant and a process for the production of concrete bent or roof tiles which overcome the drawbacks of the prior art mentioned above.

In particular, it is an object of the present invention to provide a plant and a process for the production of concrete roof tiles or tiles capable of producing a highly qualitative and varied coloring.

Said object is fully achieved by the plant for the production of bent tiles or concrete roof tiles object of the present invention, comprising:

- feeding means configured to continuously supply a mixture of cement and sand,

- a forming station located downstream of the feeding means and comprising a pressure extrusion unit designed to receive said mixture and configured to compact and deform it in order to create a succession of slates or tiles, said slates or tiles having a lower surface , supporting, and an upper surface opposite to said lower surface,

- a drying station arranged downstream of the forming station and comprising a storage warehouse designed to accommodate a plurality of bent or roof tiles for a predetermined time interval such as to allow them to dry, and

- movement means active at least between the forming station and the drying station to transport said bent or roof tiles in succession.

According to the invention, the plant is characterized in that it comprises a coloring station interposed between the forming station and the drying station, said coloring station comprising at least one paint tank and at least one spraying member connected to said tank and configured to spray said paint by nebulizing it on the upper surface of each tile or tile in order to achieve an aging effect on said tile or tile.

In particular, the spraying member and the handling means are associated in such a way as to allow relative movement between the tile and the spraying member itself along two substantially orthogonal directions, giving the station maximum coloring versatility. .

In this way it is possible to create stripes and / or spots of any shape and size. Furthermore, the atomization of the paint (acrylic) allows to obtain a particularly gradual and natural shading effect.

In other words, streaks or spots are created on the tile or tile, nebulized, shaded or sprayed, thus reproducing various color effects which, seen when the roof is finished, determine aesthetic variations on the roofs.

Advantageously, in this way plays of shades are recreated on the tiles that recall the typical effects of aged roofs in their appearance.

In this regard, the coloring station preferably comprises a plurality of spraying members (more preferably at least three) which are movable and activated independently to produce spots or stripes of different color and shape on the tile (or on subsequent tiles).

In other words, the coloring station creates essentially â € œrandomâ € effects on the tiles by spraying (acrylic) paints of various colors on the fresh tiles, each applied in a different way from the others.

It should be noted that, as already mentioned, the coloring is performed on the â € œfreshâ € tile, ie immediately downstream of the molding and before drying.

This and other characteristics will be more evident from the following description of a preferred embodiment, illustrated purely by way of non-limiting example in the accompanying drawing tables, in which:

Figure 1 illustrates a schematic side view of a plant for the production of bent tiles or concrete roof tiles, according to the present invention;

- figure 2 shows a schematic plan view of a portion of the plant of figure 1;

- figure 3 and figure 4 are sectional views of successive work stations of the plant of figure 1; - figure 5 is a perspective view of a coppo or tile made by means of the method and the system according to the present invention.

With reference to the attached figures, the number 1 indicates a plant for the production of bent tiles 100 or concrete roof tiles according to the present invention.

For descriptive simplicity, from now on, reference will be made in the text to the production of 100 tiles only without however losing the generality, since everything related to tiles is equally applicable to roof tiles.

The term coppo therefore means curved tiles, each having a first surface and a second surface opposite each other.

In use, the first surface is substantially a lower surface 100a, supporting the tile 100, while the second surface is an upper surface 100b, facing externally to the roof.

Therefore, the upper surface 100b of the tile 100 has greater aesthetic value, while the lower one 100a has particular relevance in the functionality of the tile 100, and in particular in the coupling with the adjacent tiles.

More precisely, the lower surface 100a is substantially concave and defines an intrados of the tile 100, while the upper surface 100b is substantially convex and defines an extrados of the tile 100 itself.

In the illustrated embodiment, the tile 100 has a wavy profile, defining a succession of apices (two) and grooves (three).

In other embodiments, however, the coppo 100 or tile could take other forms such as, for example, the DoppioCoppo®, Coppoportoterdam®, the DoppioRomana or the like.

The plant 1 comprises a plurality of operationally successive stations, and in particular at least one forming station 2, a coloring station 3 and a drying station 4. Preferably, the plant also comprises a coating station 5.

To transport each tile 100 between one station and the next (and preferably also inside each station), the plant 1 comprises handling means 6 configured to transport the tiles 100 in succession along a predetermined direction of advance â € œAâ €.

Furthermore, the handling means define a support surface â € œBâ € for the tiles during their movement.

Preferably, the handling means 6 are configured to transport a succession of tiles 100 between one station and the next, allowing substantially continuous production (or processing) of the same.

In the preferred embodiment, the handling means 6 comprise a conveyor belt 6a, extending at least between the forming station 2 and the drying station 4.

Between the drying station 4 and the coating station 5 it is possible to provide a further conveyor belt 6b or a continuation of the conveyor belt 6a.

However, it is preferable to provide for the presence of an additional belt in order to free the construction and storage of the tiles in the drying station from the finishing and storage of the same.

Preferably, the plant 1 comprises means 7 for feeding an incoherent mixture 101 of sand and cement to the forming station 2.

Therefore, the handling means 7 are operationally located upstream of the forming station 2. More particularly, this incoherent mixture 101 comprises a portion (or dose) of sand, a portion of cement, a portion of water and, preferably, a portion of coloring material which, added to the mixture, allows to obtain tiles with numerous and different colors without the need for subsequent painting.

Preferably, the coloring material is iron oxide or the like.

In the preferred embodiment, the portion of sand of the mixture 101 comprises sand having a fine particle size, ie with a diameter of less than 1 mm, preferably less than 0.5 mm.

Furthermore, in the mix 101 the portion of cement is particularly high, preferably between 35% and 55% of the quantity (in kg) of sand, more preferably between 40% and 50%.

Advantageously, in this way the resulting mix has characteristics of high plasticity and compactness, which gives the tile great compactness and surface smoothness.

The feeding means 7 are preferably defined by a conveyor 7a, configured to receive and transport the dough 101 from a loading area (not shown) to an unloading area 7b near the forming station 2.

This forming station 2 is configured to make tile 100 starting from mix 101.

In the preferred embodiment, the forming station 2 comprises a press-extruder member 8a suitable for making the tile 100 by extruding the mixture from a matrix.

Therefore, the forming station 2 comprises a pressure extrusion unit 8.

The press-extrusion unit 8 comprises a box 9 (with a substantially quadrilateral section) extending away from the support surface â € œBâ € defined by the handling means 6.

This crate 9 has an upper opening 9a for receiving the dough 101 (falling by gravity). Consequently, the handling means 7 face the case 9, and in particular the opening 9a.

Furthermore, the box has a lateral access mouth 9b shaped to accommodate a train of adjacent base molds 50.

These base molds 50 are counter-shaped to the lower surface 100a of the tile 100.

Facing and opposite the access mouth 9a, the box 9 comprises a roller 9c, rotating around a transverse axis (orthogonal) to the direction of advancement â € œAâ € (and parallel to the supporting surface â € œBâ €).

This roller 9c is counter-shaped to the upper surface 100b of the tile 100, and is configured to drag the mixture out of the box 9.

In this regard, the box has an outlet 9d, facing the roller 9c, which is also counter-shaped to the upper surface 100b of the tile 100.

In the illustrated embodiment, the roller 9c has a wavy profile defined by a succession of apexes and grooves.

Likewise, the outlet 9d also has a wavy profile.

Therefore, the roller 9c, together with the movement of the base mold 50 along the advancement direction â € œAâ € drags and pushes the dough out of the outlet 9d, which is in effect an extrusion die.

In other words, the forming station 2 produces the lower surface 100a of the tile 100 by molding (by pressing the mixture onto the base mold 50) and the upper surface 100b by extrusion.

Immediately downstream of the outlet 9d, the forming station 2 comprises a cutting member 10 (or cutter) cyclically moving towards and away from the supporting surface â € œBâ € to cut the extruded dough 100, separating a portion of a tile 100 (and the relative mold 50) from a front portion of the following tile (with the relative mold 50).

Note that the base mold 50 supports the tile 100 and rests on the supporting surface â € œBâ € (i.e. on the conveyor belt 6a).

Said base mold 50 is therefore associated with the handling means 6, and in particular with the conveyor belt 6a.

In fact, during the production process, each tile 100 remains associated with its own mold 50 during the advancement between the stations.

In other words, plant 1 is equipped with as many 50 molds as there are 100 tiles that can be stored and produced.

Preferably, each mold 50 is made of aluminum alloy or other material particularly resistant to the compression that it undergoes during the extrusion step.

Plant 1 also includes, downstream of the molding station 2, a coloring station 3 capable of creating a particular coloring on the upper surface 100b of the tiles 100 which recalls that aging effect which, due to exposure continues to atmospheric agents, it is created over time on traditional tiles.

The coloring station 3 is therefore interposed between the forming station 2 and the drying station 4. In other words, the coloring station 3 is arranged immediately downstream of the forming station 2 so that the paint is applied directly on the â € œfreshâ € mixture of the 100 tile.

The term â € œfreshâ € in this text defines the tile formed but not yet dried, therefore just released from the molding station 2. In other words, the plant 1 does not foresee the presence of a grouting machine between the forming 2 and the coloring station 3, and more generally between the forming station 2 and the drying station 4.

Consequently, coloring is carried out in the coloring station 3 directly on the fresh mixture coming out of the forming station 2 which, also thanks to the quality of the mixture 101, can do without the cement grout.

It comprises at least a tank 11 for a paint having a color different from the roof tile or tile 100 and at least one spraying member 12 connected to the tank 11.

This spraying member 12 is configured to draw the paint from the tank 11 and nebulize it, spraying it towards the upper surface 100b of the tile 100 so as to produce a stain or a colored strip.

Advantageously, the nebulization allows to obtain spots and stripes with gradual shades.

Note that the paint inside the tank is water based, preferably acrylic.

Alternatively, a vinyl or styrene-acrylic paint could be used.

Preferably, the spraying member 12 comprises a nozzle 13 and a depressor device 14 configured to create a depression in correspondence with the nozzle 13 itself in order to spray the paint, nebulizing it.

In other words, the depressor device is configured to generate a depression in correspondence with an outlet of the nozzle 13, so as to create a suction of the paint, which is sprayed in the direction of the conveyor belt 6a (therefore of the tile 100).

Consequently, the nozzle 13 operates for the â € œventuri effectâ €. Alternatively, it would be possible to use â € œairlessâ € type nozzles, ie equipped with mobile pumps and / or membranes that generate a thrust on the fluid leaving the nozzle itself. In a further alternative, airbrushes could also be used.

In this way, 100 strips or stains are created on the tile, nebulized, shaded or sprayed to create various color effects which, seen when the roof is finished, determine aesthetic variations on the roofs.

In the preferred embodiment, the coloring station 3 comprises a support structure 15, having a pair of uprights (not shown) that move away from the supporting surface â € œBâ € of the tiles 100 and a crosspiece 15a extending along the direction of advance. â € œAâ € of handling equipment 6.

Preferably, the spraying member 12 is connected to this crosspiece 15a, oriented towards the supporting surface â € œBâ € (ie towards the conveyor belt 6a and therefore towards the tiles 100 to be colored).

Preferably, the spraying member 12 and the handling means 6 are associated so as to allow relative movement between the handling means 6 (and therefore the tile 100) and the spraying member 12 itself along two directions between they are substantially orthogonal, giving the coloring station 3 maximum operating versatility.

In the illustrated embodiment, the handling means 6 transport the tile 100 along the direction â € œAâ € of advancement, while the spraying member 12 is movable transversely, preferably orthogonally, to this direction.

In this way, it is possible for the nozzle 13 to produce colors (stripes or spots) in any area of the tile 100, with the most varied shapes.

Preferably, the coloring station 3 comprises at least one actuator (not shown) connected to the spray member 12 to move it transversely to the direction of advancement â € œAâ €.

In particular, the sprinkler member 12 is pivoted to the crosspiece 15a to rotate with respect to it around an axis of rotation substantially parallel to the direction of advancement â € œAâ €.

In the illustrated embodiment, the sprayer 12 comprises an arm 12a extending between two opposite ends, one pivoted to the crosspiece and the other associated with the nozzle 13. Said actuator (not shown) being connected to the arm 12a to rotate it.

Alternatively, it would be possible to give the sprayer a plurality of directions of movement, so as to be able to perform the coloring even with the handling means disabled inside the station (for example with a double rotation, around two orthogonal axes , or by linear movement along two perpendicular axes or a combination of the two).

Preferably, the coloring station 3 comprises a plurality of spraying members 12 and a corresponding plurality of paint reservoirs 11, each provided with a paint of a different color, to produce spots or stripes of a different color on the tile 100 (or tile).

Advantageously, in this way it is possible to obtain 100 variegated tiles, presenting shades of different types, shapes and colors.

In the illustrated embodiment, the coloring station comprises three spraying members 12, each in fluid connection with its own paint tank 11.

In this regard, the system 1 (and in particular the staining station 3) comprises a control unit 17 connected to the spraying members 12 to activate and / or move them independently of each other in function of a predetermined sequence of colors to be carried out on the bent tiles 100 or tiles.

More precisely, the control unit 17 is programmed to process a â € œrandomâ € sequence of operations that each sprinkler must perform, controlling each actuator and each nozzle 13 accordingly. Advantageously, in this way it is possible to differentiate each tile from the next, in order to increase the â € œnaturalâ € effect within a single batch of 100 tiles.

Therefore, the acrylic spraying on fresh tiles takes place with various different colors and applied in different ways (along different trajectories).

In order to recreate roofs with a lived-in look, these applications are therefore made random and non-repetitive through the use of a color spraying time management module inside the control unit 17.

In this way, it is possible to recreate elements of discontinuity and randomness typical of aged roofs. The plant 1 also includes, as already mentioned above, a drying station 4 arranged downstream of the coloring station 3.

Said drying station 4 comprises a magazine 4a configured to house a plurality of fresh and colored tiles 100, for a predetermined time interval (and at a predetermined temperature) to allow them to dry and prepare the finish.

Preferably, this magazine 4a has an inlet 4b arranged in front of the conveyor belt 6a to receive the tiles 100 in succession.

In the preferred embodiment, the magazine 4a comprises a (substantially circular) tower 18 which rotates around its own axis of vertical rotation.

This tower 18 comprises a plurality of adjacent circular sectors 18a.

Each corner sector 18a has a plurality of drawers 19 stacked together and sliding vertically along a suitable track. More precisely, these drawers 19 (each connected to the drawers adjacent to it) slide along a closed path by means of suitable sliding means (not shown). In this way, each drawer returns to its initial position once the scroll cycle has finished. Each of the drawers 19 is designed to house inside a tile 100 to be dried, and therefore in its own working position it defines the inlet 4b of the warehouse 4a.

The control unit 17 (specific or shared with the coloring station 3) is responsible for controlling the rotation of the tower and the corresponding sliding of the drawers, in order to manage the correct filling of the magazine 4a.

More precisely, once each drawer 19 has received a colored tile 100 inside, the control unit activates the sliding means of the circular sector placed in the operative position to move the filled drawer 19 and position it in front of the conveyor belt 6a a further empty drawer 19.

This operation is repeated until saturation of the circular sector 18a (comprising about 100 drawers 19).

Subsequently, the control unit commands the rotation of the tower 18 to bring into the operative position a circular sector 18a adjacent to the previous one.

These operations are preferably repeated until the warehouse 4a is saturated.

It should be noted that inside the warehouse 4a the drying temperature of the tiles 100 is substantially in a range between 30 ° C and 40 ° C, preferably around 35 ° C.

It should be noted that, if during the loading of the magazine the tiles are loaded vertically, ie circular sector by circular sector, during the magazine unloading the wheel 18 is unloaded horizontally, ie floor by floor.

Advantageously, in this way each batch of tiles 100 has the maximum possible color variability.

At the outlet from the warehouse 4a, the drying station 3 provides for the presence of separator means (not shown) suitable for separating each tile 100 from its own mold 50.

More precisely, these separator means comprise a plurality of support members movable horizontally to insert themselves between the tile 100 and the mold 50, so as to keep the tile 100 raised while the mold advances along a recovery chute.

A recirculation device (preferably a line of belts) is interposed between the drying station and the forming station 2 to bring the molds back to the inlet of the box 9.

Preferably, the plant 1 further comprises a coating station 5.

Preferably, the coating station 5 comprises an element for applying (not shown) a layer of transparent varnish on the tile 100 in order to increase its resistance and impermeability.

Preferably, the applicator element is defined by a pumping member able to nebulize the transparent paint by means of special nozzles.

In the preferred embodiment, the transparent varnish is also of the acrylic type.

Preferably, the coating station 5 is located downstream of the drying station 4.

Consequently, the handling means 6 are also active between the drying station 4 and the coating station 5. Preferably, a further conveyor belt 6b extends between an outlet 4c of the magazine 4a and a packing station (not illustrated ) of 100 finished tiles.

In this embodiment, the drying of the transparent varnish takes place during the time that elapses between its application and the arrival of the tile 100 at the packing station, terminal of the plant.

Alternatively, the coating station could be located upstream of the drying station 4, interposed between the coloring station 3 and the magazine 4a.

The object of the present invention is also a process for the production of bent tiles 100 or concrete roof tiles, comprising a succession of phases, preferably carried out by the plant 1 described up to now.

The process provides for a preliminary stage of preparation of a mixture 101 comprising cement and sand.

Preferably, as already mentioned in relation to the plant 1, the mixture 101 comprises a portion of fine sand and a portion of cement.

In particular, this incoherent mixture 101 comprises a portion (or dose) of sand, a portion of cement, a portion of water and, preferably, a portion of coloring material which, added to the mixture, allows to obtain tiles having numerous and different colors without the need for subsequent painting. Preferably, the coloring material is iron oxide or the like.

In the preferred embodiment, the portion of sand of the mixture 101 comprises sand having a fine particle size, ie with a diameter of less than 1 mm, preferably less than 0.5 mm.

Furthermore, in the mix 101 the portion of cement is particularly high, preferably between 35% and 55% of the quantity (in kg) of sand, more preferably between 40% and 50%.

Advantageously, in this way the resulting mix (mixture) has characteristics of high plasticity and compactness, which gives the tile great compactness and surface smoothness.

Once the mixture has been prepared, the procedure involves a phase of forming a tile 100 by means of a process of press-extrusion of a portion of the mixture.

Immediately downstream of the forming, the process provides for coloring an upper face of the tile 100 by means of a nebulization of a colored paint on a predetermined portion of this upper surface. Advantageously, in this way it is possible to create a stain or a strip on the mixture 101 of said tile that is still fresh, that is, just formed and not dried.

Preferably, the coloring step provides for spraying, by means of a plurality of nozzles 13, a corresponding plurality of different paints (for coloring) in order to obtain a tile 100 with a variegated color. Note that the paint is a water-based acrylic type.

In particular, the spraying phase takes place by moving each spray nozzle 13 transversely to a direction of advancement â € œAâ € of the tile 100.

After coloring, the procedure involves drying each tile 100 for a predetermined time interval, at a low temperature (between 30 ° C and 40 ° C, preferably at around 35 ° C).

The procedure also involves a phase of application of a layer of transparent varnish (or patination) on the tile 100, in order to increase the finish and waterproofness of the tile 100 itself.

Preferably, this step is performed downstream of drying.

However, it is possible to foresee a coating phase before drying.

The invention achieves the intended purposes and achieves important advantages.

In fact, coloring with acrylic immediately downstream of the molding makes it possible not to use the grouting machine, with consequent improvements both in terms of quality and timing.

Furthermore, the use of spray nozzles allows to increase the shading effects on the tile, making it more adjacent to the real aging of the tile.

Moreover, the presence of a plurality of nozzles, each configured to perform a specific coloring and controlled in a â € œrandomâ € (random) way allows to exponentially increase the possibilities of coloring the tile.

This increase in versatility is also improved by the presence of a multi-level revolving magazine.

Claims (11)

CLAIMS 1. Plant for the production of bent tiles or concrete roof tiles, comprising: - feeding means (7) of a mixture (101) of cement and sand; - a forming station (2) located downstream of the feeding means (7) and comprising a pressure extrusion unit (8) designed to receive said incoherent dough (101) and configured to compact and deform it in order to create a succession of bent or roof tiles, said bent tiles (100) having a lower surface (100a), for support, and an upper surface (100b) opposite said lower surface; - a drying station (4) arranged downstream of the forming station (2) and comprising a storage warehouse (4a) designed to accommodate a plurality of tiles (100) for a predetermined time interval such as to allow drying of the same; - movement means (6) active at least between the forming station (2) and the drying station (4) to transport said tiles (100) in succession along a predetermined direction of advancement (A); characterized in that it comprises a coloring station (3) interposed between the forming station (2) and the drying station (3); said coloring station (3) comprising at least one tank (11) of a paint having a color different from the tile (100) and at least one spraying member (12) connected to said tank (11) and configured to nebulize said paint in order to spray it on the upper surface (100b) of each tile (100) so as to create a stain or a strip on said tile (100). 2. Plant according to claim 1, characterized in that the coloring station (3) is arranged immediately downstream of the forming station (2) so that the paint is applied directly on the fresh mixture of the tile (100) or tile. 3. Plant according to claim 1 or 2, characterized in that the coloring station (3) comprises at least one actuator (12a) connected to said at least one spraying member (12) to move it transversely to the direction of advancement (A) of the handling equipment (6). 4. System according to any one of the preceding claims, characterized in that said spraying member (12) comprises a nozzle (13) and a depressor device (14) configured to create a vacuum in correspondence with said nozzle (13) to spray the paint nebulizing it. 5. Plant according to claim 4, characterized in that the coloring station (3) comprises a plurality of spraying members (12) and a corresponding plurality of paint tanks (11), each provided with a paint of a different color, for create stains or stripes of a different color on the tile (100). 6. Plant according to claim 5, characterized in that it comprises a control unit (17) connected to the spraying members (12) to activate and / or move them independently of each other, according to a predetermined sequence of colors to be performed on the same tile (100) or on subsequent tiles. 7. Plant according to any one of the preceding claims, characterized in that it comprises a coating station (5) comprising an element for applying a layer of transparent varnish on the tile or tile in order to increase its finish and waterproofness. 8. Process for the production of bent or roof tiles in concrete, comprising the phases of: - preparation of a mixture (101) comprising cement and sand; - forming a tile (100) by means of a pressure extrusion process of a portion of said mixture (101), said tile (100) having a lower face (100a), supporting, and an upper face (100b); - drying said tile (100) at a predetermined temperature for a predetermined time interval; characterized in that it comprises a coloring step of the upper surface (100b) of said tile (100) immediately downstream of the forming step, said coloring step being performed by nebulizing a colored paint on a predetermined portion of said upper surface (100b) in order to create a stain or a stripe on the mixture of said tile (100) still fresh. 9. Process according to claim 8, characterized in that said paint is of the water-based acrylic type. 10. Process according to claims 8 or 9, characterized in that said mixture (101) comprises a portion of fine sand, having a particle size of less than one millimeter, and a portion of cement. 11. Process according to any one of claims 8 to 10, characterized in that it comprises a step of applying a layer of transparent varnish on the colored tile (100).