Technical Field

The present invention relates to an equipment and a process for the manufacture of slabs made of ceramic and/or stone material and/or made of mineral grits bound with resins.

Background Art

The need is well known in many sectors of industrial activity to renew the manufactured products and to search for new ones in order to distinguish them from those of the competition.

This need is felt, in particular, in the industry dealing with the manufacture of slabs made of ceramic and/or stone material and/or made of mineral grits bound with resins used for making, e.g., tiles for floors and/or coverings.

Nowadays the market requires more and more special aesthetic effects, such as e.g. the reproduction of the aesthetic effects of natural rocks, such as marble or granite, characterized by the presence of “grains”, i.e. streaks of different color than the basic material, having an irregular pattern and crossing the entire thickness thereof.

The manufacture of slabs generally involves a phase of deposition of a plurality of materials to be compacted, which may consist of ceramic powders or a mixture of mineral compounds in granular form (e.g. marble, granite), glass, fragments of mirrors, quartz powder, etc., as well as resins acting as binders, on a supporting surface, such as a belt or a mold, to form a slab to be compacted. During this deposition, the materials are arranged on the supporting surface in order to define the final aesthetic effect of the slab.

Depending on the type of materials used, further phases are then carried out, such as e.g. firing and subsequent cooling, in the case of ceramic and/or stone materials, or vacuum vibratory pressure, in the case of mineral grits and resins. These operations give the finished slab the characteristic properties of physical and mechanical strength. An equipment of known type comprises the use of a hopper which extends for the entire width of the slab to be obtained and inside which the materials to be deposited on the supporting surface are loaded.

The relative movement between the latter and the hopper results in the extraction of the materials from the hopper itself.

In order to obtain special chromatic effects, such as e.g. a “grained” effect, a plurality of different types of materials are deposited inside the hopper, which stratify inside the hopper itself and are then deposited in succession on the supporting surface.

The equipment of known type does however have some drawbacks.

In fact, due to the friction of the material on the internal walls of the hopper, the flow of the material out of the hopper itself is not even and random, so the intensity of the color of the grains obtained is blurred or inaccurate and especially difficult to reproduce.

Moreover, the material exiting the hopper, coming into contact with the end portion of the walls, is partly dragged on the surface of the slab with a consequent alteration of the desired aesthetic effect.

Last but not least, the slabs thus obtained do have veins that are “longitudinal” with respect to the surface of the slab, i.e. they do not pass through the entire thickness thereof. This drawback prevents, therefore, a so-called “passing grain”, typical of natural rocks, from being obtained and which is particularly evident in the case wherein coverings are to be made with two surfaces orthogonal to each other, as in the case of worktops for kitchens, bathrooms, or other similar applications, for which it is not possible to obtain a grain substantially continuous along the two orthogonal surfaces.

Description of the Invention

The main aim of the present invention is to devise an equipment and a process for the manufacture of slabs made of ceramic and/or stone material and/or made of mineral grits bound with resins which allow a wide variety of aesthetic effects to be obtained in a simple and reliable manner.

Another object of the present invention is to devise an equipment and a process for the manufacture of slabs made of ceramic and/or stone material and/or made of mineral grits bound with resins, which allow making slabs provided with delineated and well-defined aesthetic effects and which are reproducible over time.

A further object of the present invention is to devise an equipment and a process for the manufacture of slabs made of ceramic and/or stone material and/or made of mineral grits bound with resins which allow obtaining slabs reproducing the chromatic effect of natural rocks as faithfully as possible.

Another object of the present invention is to devise an equipment and a process for the manufacture of slabs made of ceramic and/or stone material and/or made of mineral grits bound with resins which allow overcoming the aforementioned drawbacks of the prior art within a simple, rational, easy and effective to use as well as affordable solution.

The aforementioned objects are achieved by the present equipment for the manufacture of slabs made of ceramic and/or stone material and/or made of mineral grits bound with resins having the characteristics of claim 1.

The aforementioned objects are also achieved by the present process for the manufacture of slabs made of ceramic and/or stone material and/or made of mineral grits bound with resins having the characteristics of claim 15.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become more apparent from the description of a preferred, but not exclusive, embodiment of an equipment and a process for the manufacture of slabs made of ceramic and/or stone material and/or made of mineral grits bound with resins, illustrated by way of an indicative, yet non-limiting example, in the accompanying tables of drawings wherein:

Figure 1 is an exploded axonometric view of the equipment according to the invention;

Figures 2-5 show the phases of the process according to the invention. Embodiments of the Invention

With particular reference to such figures, reference numeral 1 globally indicates an equipment for the manufacture of slabs made of ceramic and/or stone material and/or made of mineral grits bound with resins.

In the context of the present disclosure, the expression “ceramic and/or stone materials” means materials of the ceramic type, in the form of atomized, grains or flakes, and/or of the stone type, such as marble, granite, minerals or other natural stones, in the form of powder and/or granules and/or flakes and mixed with a binder of a cement nature or resins. Similarly, the expression “mineral grits and resins” means minerals in a granular form, e.g., marble, granite, glass, mirror fragments, and/or the like, as well as quartz powder, while resins may be, e.g., of the thermosetting type, especially for construction and furniture applications.

The equipment 1 according to the invention comprises: a supporting surface 2; at least one molding grid 3 positionable resting on the supporting surface 2 and delimiting with the latter a plurality of collecting cavities 4 separate from each other; at least one filling jig 5a, 5b positionable on the molding grid 3 and comprising at least one opening 6a, 6b adapted to be superimposed onto at least one of the collecting cavities 4a, 4b and at least one closure wall 7a, 7b adapted to be superimposed onto the remaining collecting cavities 4; and dispensing means 8 for dispensing at least one material Ml, M2 of the ceramic and/or stone type and/or of the mineral grit and resin type, through the opening 6a, 6b so as to fill the corresponding collecting cavity 4a, 4b to obtain a slab to be compacted L.

In the embodiment shown in the figures, the supporting surface 2 is movable along a direction of forward movement D. In this case, the supporting surface 2 is of the type of a conveyor belt.

Embodiments cannot however be ruled out wherein the supporting surface 2 is of the fixed type.

Conveniently, the equipment 1 comprises a plurality of molding grids 3 positionable on the supporting surface 2, in succession along the direction of forward movement D, so as to allow manufacturing several slabs to be compacted L in a continuous cycle.

The molding grid 3 allows obtaining decorative effects reproducible over time in a very practical way.

As shown in Figure 2, the molding grid 3 comprises a plurality of perimeter walls 9 which delimit an internal volume defining the final dimensions of the slab to be compacted L. As shown by way of example in the figures, the molding grid 3 has four perimeter walls 9, arranged in a rectangle fashion. It cannot however be ruled out that the molding grid 3 having a different conformation or featuring a different number of perimeter walls 9, depending on the shape that is intended to be given to the slab to be compacted L.

The molding grid 3 also comprises a plurality of internal walls 10 each extending between the perimeter walls 9. In addition, the internal walls 10 extend vertically until they contact the supporting surface 2.

The internal walls 10 subdivide the internal volume into the aforementioned collecting cavities 4.

The collecting cavities 4 are, therefore, delimited inferiorly by the supporting surface 2 and are open at the top to allow filling the molding grid 3.

The collecting cavities 4 are adapted to contain a plurality of different types of material Ml, M2 of the ceramic and/or stone type and/or of the type of mineral grits and resins.

Specifically, the types of material Ml, M2 differ in at least one of either grain size, color or composition.

The collecting cavities 4 are adapted to contain at least two types of material Ml, M2 so as to obtain a slab to be compacted L provided with a predefined decorative effect and, in particular, a “grained” effect.

More in detail, the molding grid 3 allows creating grains made of different materials and which affect the entire thickness of the slab, so as to recreate the aesthetic effect typical of natural rocks.

Conveniently, the collecting cavities 4 comprise one or more first collecting cavities 4a adapted to contain a first type of material Ml of the ceramic and/or stone type and/or of the mineral grit and resin type and one or more second collecting cavities 4b adapted to contain a second type of material M2 of the ceramic and/or stone type and/or of the mineral grit and resin type, other than the first type of material Ml.

The filling jig 5a, 5b is positionable on the molding grid 3 so as to allow selective filling of the collecting cavities 4 by the dispensing means 8 with a specific type of material Ml, M2.

In more detail, the filling jig 5a, 5b is of the type of a slab- shaped body on which the openings 6a, 6b are formed.

The filling jig 5a, 5b is at least as large as the size of the molding grid 3. In other words, the filling jig 5a, 5b completely superimposes onto the molding grid 3. The function of the filling jig 5a, 5b is to obstruct part of the collecting cavities 4 and keep the others open.

In this manner, the dispensing means 8 are able to dispense one of the types of material Ml, M2 into the open collecting cavities 4a, 4b and not into the obstructed ones.

This device allows obtaining extremely defined decorative effects avoiding the so-called “blurred effect” which is generally obtained with the known type of equipment.

The closure wall 7a, 7b, in fact, causes the materials Ml, M2 to be distributed only in the respective open collecting cavities 4a, 4b, thus avoiding unwanted mixing.

With the filling jig 5a, 5b positioned on the molding grid 3, the closure wall 7a, 7b contacts the top edge of the internal walls 10, occluding the collecting cavities 4 both superiorly and laterally, thus preventing the material from flowing from an open collecting cavity 4a, 4b to the closed collecting cavities 4. Advantageously, the opening 6a, 6b has a conformation corresponding to the conformation of the collecting cavity 4a, 4b onto which it superimposes.

In other words, the collecting cavity 4a, 4b, onto which the opening 6a, 6b is superimposed, is completely open at the top. In this way, the filling of the collecting cavity 4 is considerably rapid and efficient. It should be noted that the filling jig 5a, 5b may have a plurality of openings 6a, 6b, each of conformation corresponding to a relevant collecting cavity 4a, 4b. In this way, the filling jig 5a, 5b allows the simultaneous filling of several collecting cavities 4a, 4b with the same type of material Ml, M2.

Conveniently, the equipment 1 comprises a plurality of filling jigs 5a, 5b positionable in succession on the molding grid 3 and each one provided with a corresponding opening 6a, 6b and with a corresponding closure wall 7a, 7b.

In more detail, the opening 6a, 6b of each filling jig 5a, 5b is arranged at one or more collecting cavities 4a, 4b other than those relating to the openings 6a, 6b of the other filling jigs 5a, 5b.

Substantially, the filling jigs 5a, 5b are complementary to each other, so as to allow all the collecting cavities 4 to be selectively filled.

Furthermore, the collecting cavities 4 at which the openings 6a, 6b of the filling jigs 5a, 5b are arranged are different from each other. In other words, each of the collecting cavities 4 may be filled with the respective material by means of a predefined filling jig 5a, 5b.

With particular reference to the embodiment shown in the figures, the filling jigs 5a, 5b comprise: at least a first filling jig 5a provided with at least a first opening 6a positionable at the first collecting cavities 4a and at least a first closure wall 7a of the second collecting cavities 4b; and at least a second filling jig 5b provided with at least a second opening 6b positionable at the second collecting cavities 4b and at least a second closure wall 7b of the first collecting cavities 4a.

The filling jigs 5a, 5b are positioned on the molding grid 3 alternately so that the materials can be dispensed into the corresponding collecting cavities 4a, 4b. Advantageously, the first filling jig 5a and the second filling jig 5b are made in a single body piece and arranged side by side.

In other words, the first and the second filling jigs 5a and 5b are made in the form of a single slab-shaped body on which the openings 6a, 6b are made.

The single body piece is positioned between the molding grid 3 and the dispensing means 8.

The single body piece is movable with respect to the molding grid 3 between a first operating configuration, wherein the first filling jig 5a is positioned at the molding grid 3, and a second operating configuration, wherein the second filling jig 5b is positioned at the molding grid 3.

Specifically, the single body piece is movable by shifting with respect to the molding grid 3 along a direction of sliding S which is transverse to the direction of forward movement D.

The filling jigs 5a, 5b are, in fact, arranged side by side transversely to the direction of forward movement D.

The dispensing means 8 are arranged above the at least one filling jig 5a, 5b.

The dispensing means 8 and the filling jig 5a, 5b are mutually movable along the direction of forward movement D.

In the embodiment shown in the figures, the dispensing means 8 are movable along the direction of forward movement D and the filling jig 5a, 5b is stationary along the direction of forward movement D.

Consequently, the dispensing means 8 are also movable with respect to the molding grid 3 along the direction of forward movement D.

During such movement, the dispensing means 8 release the material Ml, M2 into the corresponding collecting cavities 4a, 4b through the opening 6a, 6b.

The dispensing means 8 comprise a plurality of hoppers 8a, 8b, each adapted to contain and dispense a type of material Ml, M2 different from the others.

The hoppers 8a, 8b have a width extension corresponding to the width of the molding grid 3. Substantially, during movement, each of the hoppers 8a, 8b completely superimposes onto the molding grid 3 thus allowing it to be filled in a single pass.

With reference to the embodiment shown in the figures, the dispensing means 8 comprise at least a first hopper 8a adapted to contain the first type of material Ml and at least a second hopper 8b adapted to contain the second type of material M2.

The hoppers 8a, 8b are arranged in succession along the direction of forward movement D.

In more detail, the hoppers 8a, 8b are positioned side by side above the supporting surface 2.

The hoppers 8a, 8b are arranged above the filling jigs 5a, 5b, in contact with the same. The contact of the hoppers 8a, 8b with the filling jigs 5a, 5b prevents the materials Ml, M2 from flowing out of the hoppers themselves.

In other words, during the movement of the hoppers 8a, 8b along the direction of forward movement D, the material Ml, M2 is released only at the openings 6a, 6b, thus allowing only the open collecting cavities 4a, 4b to be filled. Conveniently, the hoppers 8a, 8b are movable independently from each other with respect to the molding grid 3 along the direction of forward movement D.

In this way, each hopper 8a, 8b is only moved with the respective filling jig 5a, 5b arranged at the molding grid 3.

More in detail, with the single body piece in a predefined operating position, each of the hoppers 8a, 8b is movable with respect to a relevant filling jig 5a, 5b along the direction of forward movement D so as to release the relevant type of material Ml, M2 inside the corresponding collecting cavity 4a, 4b.

Depending on the materials used, the equipment 1 may then comprise further components adapted to give the finished slab the desired properties of physical- mechanical strength.

In more detail, the equipment 1 comprises compaction means and curing means, not shown in detail in the figures, arranged in succession along the direction of forward movement D, downstream of the dispensing means 8.

Specifically, in the case of ceramic and/or stone materials, the compaction means are of the type of a press and the curing means are of the type of a firing kiln. As is known to the technician of the sector, in fact, the slab to be compacted L made of ceramic and/or stone material is first subjected to compaction and then fired at high temperatures to obtain the finished slab.

On the other hand, in the case of mineral grits and resins, the compaction means are of the type of a vacuum vibratory press and the curing means are of the type of a heated chamber. The slab to be compacted L made of mineral grits and resins is subjected to a vibrating action, which facilitates the adhesion of the grits, in a depressurized environment so as to eliminate the air present in the interstices between the mineral grits and further optimize the compaction of the slab to be compacted L. Then, the catalysis of the resins binding the grits together takes place inside the heated chamber.

The operation of the present equipment 1 in carrying out the process according to the invention is as follows.

The process according to the invention comprises, first of all, a supply of a plurality of materials Ml, M2 of ceramic and/or stone type and/or of mineral grit and resin type.

As stated above, the types of material Ml, M2 differ in at least one of either grain size, color or composition, so as to obtain a slab to be compacted L provided with a special decorative effect.

The process also comprises a supply of the equipment 1 as described above. Initially, the molding grid 3 is positioned resting on the supporting surface 2.

In such a position, the molding grid 3 delimits with the supporting surface 2 a plurality of collecting cavities 4 separate from each other. (Figure 2)

The supporting surface 2, movable along the direction of forward movement D, carries the molding grid 3 to the dispensing means 8.

Next, the process comprises the phases of: obstruction of a part of the collecting cavities 4 so as to identify at least one open collecting cavity 4a, 4b; filling of the at least one open collecting cavity 4a, 4b with at least one of the type of material Ml, M2; and repetition of the obstruction and filling phases for each of the collecting cavities 4 to obtain a slab to be compacted L.

Finally, the process comprises a phase of removing the molding grid 3 from the supporting surface 2 to obtain a slab to be compacted L.

Advantageously, the obstruction phase is carried out by means of the filling jig 5a, 5b.

The filling jig 5a, 5b allows the collecting cavities 4 which are not to be filled with the material to be completely closed while others to be left open.

In addition, the conformation of the opening 6a, 6b, corresponding to that of the open collecting cavities 4a, 4b, allows filling the same in a quick and precise manner.

As set forth above, the equipment 1 comprises a first filling jig 5a and a second filling jig 5b, which are made in a single body piece and which allow selective filling of the molding grid 3 with two separate types of material Ml, M2.

Thus, the obstruction phase comprises at least one phase of positioning the filling jig 5a, 5b in a predefined operating position.

In more detail, the positioning is carried out by means of sliding the single body piece along the direction of sliding S.

The sliding of the single body piece with respect to the molding grid 3 allows, therefore, a first positioning of the first filling jig 5a on the molding grid 3 to allow filling the first collecting cavities 4a and, subsequently, a second positioning of the second filling jig 5b on the molding grid 3 to allow filling the second collecting cavities 4b.

Conveniently, the filling phase is carried out by means of the dispensing means

8.

The filling phase comprises: a first dispensing of the first type of material Ml, M2 into the first collecting cavities 4a; and a second dispensing of the second type of material Ml, M2 into the second collecting cavities 4b.

Specifically, the filling phase comprises at least one movement of one of the hoppers 8a, 8b along the direction of forward movement D.

In more detail, the first dispensing is carried out by moving the first hopper 8a, with the first filling jig 5a in the first operating configuration. (Figures 2 and 3) The second dispensing is carried out by moving the second hopper 8b, with the second filling jig 5b in the second operating configuration. (Figure 4 and 5)

At the end of filling, the molding grid 3, containing the materials Ml, M2, is moved along the direction of forward movement D and moved away from the dispensing means 8.

The molding grid 3 is, then, raised from the supporting surface 2 by releasing the materials Ml, M2 thereon and thus forming the slab to be compacted L.

The process, finally, comprises a compaction phase of the slab to be compacted L to obtain a compacted slab and a curing phase to obtain the finished slab.

The compaction phase and the curing phase are carried out by the compaction means and the curing means described above, respectively.

It has in practice been ascertained that the described invention achieves the intended objects, and in particular the fact is emphasized that the present equipment and the present process allow a wide variety of aesthetic effects to be obtained in a simple and reliable manner.

This result is achieved thanks to the combination of the molding grid and the filling jig to allow a selective filling of the collecting cavities, reproducing as faithfully as possible the chromatic effect of natural rocks. Moreover, the complete obstruction of a part of the collecting cavities makes it possible to avoid that, during the filling of the open collecting cavities, the materials flow into the closed collecting cavities thus jeopardizing the final result. This allows the creation of slabs provided with delineated and well- defined aesthetic effects which can be reproduced over time.