Patent ID: 12186934

EMBODIMENTS OF THE INVENTION

With particular reference to these figures, reference numeral1globally indicates a system for the production of slabs made of mineral grits bound with resins.

The system1comprises:at least one molding support2positioned resting on a support surface3movable along a direction of forward movement D;dispensing means4of at least one basic mixture B comprising mineral grits and resins on the molding support2so as to obtain a slab to be compacted L;compacting means5of the slab to be compacted L to obtain a compacted slab C;hardening means6of the compacted slab C to obtain a slab made of mineral grits.

Within the scope of the present discussion, mineral grits and resins are meant to be minerals in granular form, e.g. marble, granite, glass, mirror fragments, and/or others, as well as quartz powder, while resins may be, e.g., of the thermosetting type, especially for construction and furnishing applications.

In the embodiment shown in the figures, the molding support2is of the type of a molding die open at the top and defining a cavity adapted to contain the basic mixture B.

In particular, the cavity has substantially the size of the slab to be obtained, unless any shrinkage that may occur in subsequent production phases.

The molding die can be made of a rigid or flexible material, e.g. made of polymeric and/or elastomeric material.

In a further embodiment, which is not shown in detail in the figures, the molding support2is of the type of a sheet, made e.g. of a paper material.

The molding support2is positioned resting on the support surface3.

The support surface3is of the type of a conveyor belt, a roller conveyor, or the like.

Further embodiment solutions cannot however be ruled out wherein the support surface3is of the fixed type and the dispensing means4are movable with respect thereto along the direction of forward movement D.

The dispensing means4comprise at least one hopper7adapted to release the basic mixture B on the molding support2.

In particular, the hopper7, as a result of the movement of the support surface3along the direction of forward movement D, deposits the basic mixture B on the molding support2so as to obtain the slab to be compacted L.

The slab to be compacted L has a laying surface facing downwards and an exposed surface S facing upwards.

The laying surface is intended, in use, to be applied on the surface to be covered, while the exposed surface S is intended, in use, to be visible.

Conveniently, the system1also comprises loading means8arranged at the point where the dispensing means4are located and adapted to load the basic mixture B inside the hopper7.

In more detail, the loading means8comprise a feeding surface9, on which the basic mixture B is deposited, moving along a direction of loading F substantially parallel to the direction of forward movement D.

The feeding surface9is of the type of a conveyor belt or the like and is adapted to transport the basic mixture B to the dispensing means4.

In the embodiment shown in the figures, the system1also comprises application means10adapted to apply at least one additional mixture A to the basic mixture B. The application means10are arranged downstream of the dispensing means4with respect to the direction of forward movement D.

More specifically, the additional mixture A comprises one or more pigments, natural or synthetic, in solid or liquid form. The additional mixture A can also be made of mineral grits bound with resins and, in this case, differs from the basic mixture B by at least one of grain size, color or composition of the mineral grits.

The application of the additional mixture A is intended to create veins in the basic mixture B, i.e. streaks of a different color than the basic mixture B. The application can be carried out according to various intensities in order to create more or less fine veins.

In particular, the application is carried out at least on the exposed surface S of the slab to be compacted L.

Alternatively or in combination, the application can also be carried out full-bodied, in order to create “through” type veins, i.e. that extend for the entire thickness of the slab to be compacted L.

Preferably, the application means10comprise at least one dispensing device11, of the type of an anthropomorphic mechanical arm, adapted to dispense the additional mixture A according to a predetermined trajectory.

The application means10can also comprise one of either a suction device and a displacement device of the basic mixture B positioned upstream of the dispensing device11and also movable along the same predetermined trajectory in order to define a groove inside which the additional mixture A is then dispensed.

In the embodiment shown in the illustrations, the application means10comprise a plurality of dispensing devices11arranged in succession along the direction of forward movement D and each adapted to dispense a respective additional mixture A to the basic mixture B.

The presence of a plurality of dispensing devices11allows obtaining a plurality of different decorative effects on the same slab.

As shown in the figures, the application means10are arranged upstream of the compacting means5.

The compacting means5are of known type and, in particular, they allow carrying out compaction by means of vibrating-pressure under vacuum.

Through this operation, the mixtures B and A are pressed and simultaneously subjected to a vibrating action, which facilitates the adhesion of the grits that make up the slab to be compacted L.

At the same time, a suction operation is carried out to create a depressurized environment in order to eliminate the air present in the gaps between the mineral grits and further optimize the compaction of the slab to be compacted L.

In order to avoid direct contact of the mixtures B and A with the compacting means5, the molding support2comprises a covering element2aadapted to cover the exposed surface S of the slab to be compacted L prior to compaction.

With reference to the embodiment shown in the figures, the covering element2ais of the type of a cover that closes the aforementioned cavity and that is placed on the exposed surface S.

Alternatively, in the embodiment in which the molding support2is of the type of a sheet of paper material, the covering element2ais also represented by a covering sheet, made of paper material, which can be positioned on the exposed surface S of the slab to be compacted L.

Afterwards, the compacted slab C is transferred to the above mentioned hardening means6.

More specifically, the hardening means6comprise a heated chamber in which the catalysis of the resins present in mixtures B and A takes place in order to obtain the slab provided with the desired mechanical and physical properties.

The system1may also comprise finishing means, not shown in the figures, adapted to finish the slab superficially and arranged downstream of the hardening means6.

Specifically, the finishing means are adapted to make at least one sanding of the exposed surface S of the slab.

The system1comprises decoration means12,13by digital printing, arranged upstream of the compacting means5with respect to the direction of forward movement D, adapted to deliver at least one ink I onto at least the basic mixture B.

The decoration means12,13are of the type of a digital ink printer, which comprises a plurality of movable heads, adapted to deliver ink I according to a predefined design.

In particular, the ink I is of the penetrating type and can penetrate into the exposed surface S of the slab to be compacted L up to a depth comprised between a range of few millimeters and the entire thickness of the slab.

According to the invention, the decoration means12,13comprise pre-decoration means12by digital printing arranged upstream of the dispensing means4.

In particular, the pre-decoration means12are arranged at the point where the loading means8are located.

The pre-decoration means12have the function of applying ink I onto the basic mixture B prior to its loading inside the hopper7.

More specifically, the pre-decoration means12have the function of giving the basic mixture B special color effects, which cannot be achieved by mixing the generally used mineral grits.

The ink I applied on the basic mixture B, after the latter has been loaded inside the hopper7and then dispensed onto the molding support2, results in color spots scattered on the slab to be compacted L.

Still according to the invention, the decoration means12,13also comprise post-decoration means13by digital printing arranged downstream of the dispensing means4.

In particular, the post-decoration means13are arranged between the application means10and the compacting means5.

The post-decoration means13have the function of finishing the decorations made by means of the application means10, following the same predetermined trajectory traced by the dispensing devices11and/or of adding new decorations according to different predefined designs, before subjecting the slab to be compacted L to the compaction phase.

Alternatively or in combination, the system1comprises additional decoration means15, shown inFIG.6, arranged downstream of the compacting means5and adapted to dispense at least one ink I on the basic mixture B and/or on the additional mixture A.

In particular, the additional decoration means15are positioned between the compacting means5and the hardening means6.

Similarly to the above, also the additional decoration means15are of the type of an ink digital printer comprising a plurality of movable heads, adapted to dispense ink I on the exposed surface S of the compacted slab C.

The additional decoration means15have the function of finishing, after compaction, the decorations present on the exposed surface S following the predetermined trajectory traced by the dispensing devices11and/or of adding new decorations according to further predefined designs, before subjecting the compacted slab C to the hardening phase.

The additional decoration means15can, therefore, dispense ink I in order to resume the decoration carried out by the decoration means12,13and/or to carry out different types of decorations.

Conveniently, the system1comprises preheating means14adapted to preheat the compacted slab C, arranged between the compacting means5and the hardening means6.

If additional decoration means15are provided, the preheating means14are positioned between the latter and the hardening means6.

The preheating means14have the function of promoting the penetration of ink I inside the compacted slab C to reach the desired depth, so that the aesthetic effect thus obtained is visible even after the exposed surface S has been sanded. The operation of the system1in the execution of the procedure according to the invention is as follows.

The procedure to which the present invention relates involves first of all the supply of the basic mixture B.

Afterwards, the basic mixture B is loaded inside the hopper7.

In particular, the basic mixture B is deposited on top of the feeding surface9and transported along the direction of loading F towards the dispensing means4.

The basic mixture B is then dispensed onto the molding support2in order to obtain a downward-facing laying surface and an upward-facing exposed surface S.

In particular, in the embodiment shown in the figures, the dispensing is carried out by means of the dispensing means4that release the basic mixture B onto the molding support2, positioned resting on the support surface3.

Advantageously, after the basic mixture B has been loaded onto the molding support2, a phase of application of at least one additional mixture A of mineral grits and resins is carried out to the basic mixture B.

In the embodiment of the system1described above, the molding support2, and therefore the basic mixture B, is moved along the direction of forward movement D by means of the support surface3until it reaches the application means10of the additional mixture A to the basic mixture B.

The application of the additional mixture A to the basic mixture B is carried out according to at least one predetermined trajectory.

Then, the compaction of the slab to be compacted L is carried out, to obtain a compacted slab C, and the hardening of the compacted slab C to obtain the slab made of mineral grits.

Prior to compaction, the procedure comprises at least one phase of decorating with ink I by digital printing at least the basic mixture B.

According to the invention, the decoration comprises a pre-decoration phase by digital printing carried out prior to the dispensing of the basic mixture B.

The phase of pre-decoration is carried out using the pre-decoration means12. Specifically, the pre-decoration is carried out on the basic mixture B deposited on the feeding surface9, before its loading inside the hopper7.

Still according to the invention, the decoration comprises one phase of post-decoration by digital printing which is carried out after the dispensing of the basic mixture B.

The phase of post-decoration is carried out by means of the post-decoration means13.

Post-decoration is conveniently carried out after the application of the additional mixture A.

Post-decoration, in fact, can be performed following the predetermined trajectory to dispense the ink I at the point where the additional mixture A is located, or according to a different predefined design.

The slab to be compacted L is then transferred by means of the support surface3to the compacting means5where the basic mixture B and the at least one additional mixture A deposited on the molding support2are compacted.

Before compaction, the procedure conveniently comprised covering the exposed surface S of the slab to be compacted L by means of the covering element2a.

In particular, as shown inFIG.4, the procedure comprises a first closure of the molding die by means of the cover.

In a further embodiment, shown inFIG.6, after compaction, the procedure comprises at least one phase of additional decoration with ink I by digital printing of the compacted slab, which is carried out by means of the additional decoration means15.

Conveniently, after compaction, the exposed surface S of the compacted slab C is freed to allow for the phase of additional decoration.

Specifically, the molding die is opened by removing the cover.

Similarly to the phase of post-decoration, the additional decoration can be carried out following the predetermined trajectory in order to dispense ink I at the point where the additional mixture A is located.

Alternatively, the additional decoration can be carried out by dispensing ink I according to a predefined design which is different from the predetermined trajectory defined by the application means10.

The decoration of the compacted slab C is then carried out on the basic mixture B and possibly also on the additional mixture A, still “wet”, i.e. before being subjected to the hardening phase.

Before the hardening phase, a phase of at least partial infiltration of ink I into the compacted slab C is carried out to allow ink I to penetrate inside its thickness.

The infiltration is conveniently carried out by preheating the compacted slab C by means of the preheating means14.

If the additional decoration is carried out, the infiltration phase is carried out after the additional decoration itself.

This preheating is preferably carried out at a temperature comprised between 30° C. and 60° C.

Preheating is preferably carried out with the exposed surface S of the compacted slab C free at the top.

In particular, with reference to the embodiment shown in the figures, preheating is carried out with the molding die open at the top.

This promotes the heating of the exposed surface S and the infiltration of ink I into the compacted slab C.

Finally, the compacted slab C is transferred to the hardening means6. (FIG.5)

The hardening phase is carried out by heating the compacted slab C, at a temperature between 100° C. and 150° C.

Conveniently, between the preheating phase and the hardening phase, the procedure comprises again covering the exposed surface S of the slab to be compacted L by means of the covering element2a.

Preferably, after the hardening phase, the slab is removed from the molding support2and the slab itself is sanded.

The sanding is carried out by partial removal of material from the slab and allows obtaining a smoother and more regular exposed surface S.

The particular solution of providing a post-decoration phase and an additional decoration carried out with penetrating ink I ensures that the sanding, as a result of the removal of material, does not alter the decorative effects given to the slab during the previous machining phases.

It has in practice been ascertained that the described invention achieves the intended objects and in particular the fact is underlined that the procedure and the system according to the invention allow obtaining slabs made of mineral grits with a wide variety of different aesthetic effects.

This is possible thanks to the decoration by digital printing of the slab prior to and, if necessary, after its compaction. The use of digital printing also allows the exact reproduction of the design created by means of the application of the additional mixture, if any.

The procedure and the system according to the invention allow making in a simple and reliable manner slabs made of mineral grits with decorative effects that remain unchanged during the whole machining and after the finishing operations.