Decorative element comprising engineered stone and method for manufacturing decorative element comprising engineered stone

Abstract

Decorative element (1) comprising a first layer (4) made of engineering stone, where the engineering stone comprises an inorganic filler bonded by an adhesive, preferably a cured thermosetting resin, where the decorative element comprises a second layer (5) arranged above the first layer, and where the second layer is made of engineering stone.

Description

[0001] This invention relates to a decorative element comprising engineered stone and to a method for manufacturing such a decorative element. The decorative element of this invention is typically manufactured in slab form and is used as a cladding for building surfaces and / or as a top for furniture (e.g., a kitchen countertop). In particular, the engineered stone of this invention is commonly known in the market as quartz.

[0002] Engineered stone comprises inorganic fillers, such as crushed stone, sand, or other minerals, and recycled ceramics or glass, bonded together by a curing resin. More specifically, engineered stone refers to a composite material formed from inorganic fillers or stone-like materials, which are bonded together by means of a curing adhesive that cures at a low temperature, where low temperature means below 500°C. The adhesive is preferably a thermosetting resin.

[0003] Traditionally, natural stone has been used as a building material, especially for finishing purposes, such as cladding for walls or floors, and for producing items like kitchen or bathroom countertops and vanity surfaces. Natural stone is extracted from mines, then cut and polished to obtain slabs or large blocks of stone in the desired shape. Due to mining, natural stone is relatively expensive and has a high environmental impact.

[0004] Therefore, in recent years, methods for manufacturing engineered stone have been developed to reduce costs and provide more environmentally friendly products. A well-known example of such methods is the so-called Bretonstone® technology, described, for example, in document WO 2007 / 138529. That document discloses a method for manufacturing engineered stone comprising the following steps: providing an inorganic filler, such as abrasive sand or quartz; mixing the stone or similar material with a binder (e.g., a resin powder) to obtain a mixture; depositing the mixture in a mold of a press having a shape and size similar to that of the final product; applying vacuum pressing to the mixture, accompanied by vibrational motion at a pre-established frequency; then hardening the resulting semi-finished product through a thermosetting process to obtain the engineered stone; and then subjecting the engineered stone to finishing steps such as cutting or polishing.

[0005] These engineered stones typically include monochrome finishes. Alternatively, they may include decorative elements that incorporate artificial textures to mimic natural stone, such as marble or granite. As disclosed in WO 2009 / 010406, such finishes are achieved by adding a colorant to the mixture before it is deposited into a mold. The mixture is carried by an annular belt above the mold and loaded into the mold itself by free-falling from the ends of the belt. The colorant is loaded onto the surface of the mixture through appropriate nozzles substantially corresponding to the ends of the belt, so that it falls into the mold uncontrolled along with the mixture. After a vibratory pressing step, pigment particles are distributed throughout the mixture, resulting in a textured effect across the entire thickness of the engineered stone. Therefore, using this technique, it is not possible to obtain designed stone with reproducible and predefined finishes.

[0006] WO 2016 / 113652 discloses an apparatus and method for producing programmable color effects in engineered stone using a computer-controlled machine. The machine is a humanoid robot or a Cartesian robot equipped with one or more nozzles for dispensing a colorant onto the surface of a mixture in a temporary support. The nozzles are connected to a tool that interacts with the surface of the mixture to create grooves or holes for receiving the color, thus mimicking marble textures. Therefore, this apparatus requires the machine to operate the mixture and provides a finish that mimics natural stone with relatively low quality resolution. This technique is slow and has limitations in the size of the simulated textures that can be imitated. Furthermore, it should be noted that the resulting pattern is subjected to vibration and pressure, so that the final pattern always differs from the initial predetermined pattern.

[0007] WO2019070621 discloses a method for improving the aesthetic quality of engineered stone by inkjet printing decorative elements onto the main surface of the stone.

[0008] As mentioned above, engineered stone is formed from inorganic fillers, which in most cases are typically formed from silica sand, particularly cristobalite. Critobalite represents the best choice for inorganic fillers in terms of hardness, durability, and most aesthetic properties. On the other hand, cristobalite, and other mineral-containing crystalline silica, if inhaled, can lead to the development of a disease called silicosis. For this reason, several attempts have been made to identify alternative inorganic fillers. These attempts, for example, as disclosed in US 20220089485 and US 20220332640, have focused on glass-based fillers or feldspar. Nevertheless, identifying organic fillers based on amorphous silica that demonstrate comparable aesthetic properties, limited cost, and consistent supply remains a challenge.

[0009] The present invention is primarily intended to provide an alternative decorative element that, according to several preferred embodiments thereof, is intended to address one or more problems present in the prior art.

[0010] According to the invention, and according to a first independent aspect thereof, a decorative element comprises a first layer made of engineered stone, wherein the decorative element includes a second layer disposed above the first layer, and wherein the second layer is made of engineered stone. According to the invention, the first layer is distinct from the second layer. Forming a multi-layered decorative element allows for the combination of the properties of different layers to obtain a decorative element that can be improved in many ways.

[0011] In the context of this invention, the engineered stone comprises at least inorganic fillers and a binder, the binder being preferably polymeric, and more preferably thermosetting.

[0012] The difference between the first and second layers can be based on multiple possibilities, which, individually or in combination, can help solve one or more of the problems in the prior art.

[0013] According to the first possibility, the engineered stone forming the first and second layers can exhibit different chemical and / or mineralogical compositions of the inorganic fillers. For example, in a preferred embodiment, the decorative element may comprise at least one layer having a first filler composition and at least one layer having a second filler composition, the first filler composition being predominantly composed of a mineral different from that containing crystalline silica, and the second filler composition being predominantly composed of a mineral containing crystalline silica. In the context of this invention, "predominantly composed of a mineral different from that containing crystalline silica" means, based on the weight of the first filler composition, that the first composition contains less than 50%, preferably less than 10%, of crystalline silica, and more preferably no crystalline silica. On the other hand, "predominantly composed of a mineral containing crystalline silica" means, based on the weight of the second filler composition, that the second composition contains equal to or greater than 50% of crystalline silica. In this way, decorative elements with desired aesthetic value can be provided, which are relatively easy to achieve with mineral-containing crystalline silica, while simultaneously limiting the total content of crystalline silica. It should be noted that, preferably, a layer having a filler composition primarily composed of minerals containing crystalline silica can exhibit a thickness equal to or less than that of a layer having a filler composition primarily composed of minerals different from those containing crystalline silica.

[0014] In a preferred embodiment, the first filler composition comprises less than 10%, more preferably less than 1%, of crystalline silica by weight. The first filler composition may comprise calcium-containing minerals or minerals other than those containing silica. The first filler composition may comprise silica-containing minerals, although in this case, it is preferred that the silica-containing minerals in the first filler composition are primarily present in amorphous silica, i.e., containing more than 50%, preferably more than 75%, more preferably more than 90% amorphous silica by weight. For example, the inorganic filler composition may include glass, recycled glass, glass frit, calcium carbonate, feldspar such as albite, and feldspar-like minerals such as nepheline.

[0015] In a preferred embodiment, the second filler composition comprises more than 50% by weight, more preferably more than 90% by weight, crystalline silica. The second filler composition may comprise silica-based minerals, most preferably quartz and / or cristobalite. In particular, the silica-based minerals form the majority of the second filler composition.

[0016] It is also possible that, in some embodiments according to the first possibility, both the first and second layers are formed of filler compositions that are primarily composed of minerals different from those containing crystalline silica, despite having different compositions, such that expensive fillers (e.g., glass frit or recycled glass) for aesthetic purposes can be limited to one layer, while cheaper fillers are used for the other, thereby reducing the overall cost of the decorative element.

[0017] It is also possible that, in some embodiments according to the first possibility, both the first and second layers are formed of a filler composition primarily composed of minerals containing crystalline silica, although with different compositions, such that expensive fillers (e.g., quartz) for aesthetic purposes can be limited to one layer, while cheaper fillers are used in the other, thereby reducing the overall cost of the decorative element.

[0018] According to the first possibility, preferably, the first and second layers are configured such that the total content of crystalline silica in the decorative element is less than 50% based on the total weight of the decorative element, preferably less than 30%, and more preferably less than 25%. For example, the second layer can be formed to be less than half the thickness of the decorative layer, such as less than one-third of the thickness. In this way, the second layer can form the upper and visible layer of the decorative element, thereby providing enhanced visibility, while the first layer can form most of the thickness of the decorative layer, minimizing the content of crystalline silica and reducing the risk of silicosis.

[0019] According to the second possibility, the first and second layers may include different colors. In this way, it is possible to obtain decorative elements with an improved aesthetic appearance. For example, according to the second possibility, the engineered stone forming the first layer contains one or more first pigments, which are different from the second pigments contained in the engineered stone forming the second layer.

[0020] According to a third possibility, one of the first and second layers can be transparent or translucent. Preferably, the first layer and the other of the second layers are opaque. For example, the engineered stone forming the transparent or translucent layer may contain an adhesive having a refractive index substantially the same as the refractive index of the filler composition of the corresponding layer. Furthermore, the engineered stone forming the transparent or translucent layer is pigment-free. In this way, the other layer of the decorative element is visible through the transparent or translucent layer, thus allowing the transparent or translucent layer to act as a protective layer for the other layer.

[0021] Preferably, the transparent or translucent layer can exhibit a thickness of less than 3 mm, more preferably less than 2 mm. By limiting the thickness of the transparent or translucent layer, the transparency of the layer itself can be increased.

[0022] In some embodiments, according to a third possibility, the decorative element may include an intermediate layer between the first and second layers. This intermediate layer may preferably include a decorative pattern visible through a transparent or translucent layer, such that the transparent or translucent layer forms a protective layer suitable for protecting the decorative pattern from abrasion and scratches. The intermediate layer may be formed according to two main alternatives described below. Furthermore, by forming the decorative pattern in the intermediate layer, the process used to manufacture the engineered stone for the first and second layers can be standardized, since the decorative pattern can be made in a separate layer.

[0023] According to a first primary alternative, the intermediate layer may include a decorative foil. For example, the decorative foil may comprise a polymer-based or paper-based sheet with a printed decoration on its top. The polymer-based sheet may be made of a polyester-based polymer or a vinyl-based polymer. In some embodiments, the paper-based sheet may be impregnated with a resin, preferably a polyester-based resin. The printed decoration may be printed using analog printing techniques (e.g., rotary gravure printing) or digital printing techniques (e.g., inkjet printing). In this way, the transition from manufacturing one product to manufacturing different products can be easily performed by changing the supply of the decorative foil. Using a polyester-based decorative foil or a polyester-impregnated paper layer can help improve the adhesion between the first and second layers of engineered stone.

[0024] According to a second primary alternative, the intermediate layer can be formed from a thin layer of engineered stone containing a printed pattern formed by colored pigments distributed according to a pattern. Preferably, the printed pattern is printed on the surface between the first and second layers. In the context of this application, direct printing means that the printing operation is performed directly on the layer, as opposed to those embodiments in which the printing operation is performed on a separate printing substrate (such as foil) which is then provided on the first layer. Preferably, the pigments forming the printed pattern are inorganic pigments.

[0025] According to any of the possibilities mentioned above, the filler composition forming the first and / or second layer of engineered stone can be in the form of powder, granules, fragments, aggregates, or any other particulate form, although granular and powder forms are preferred. Preferably, the filler is in powder form having an average particle size of less than 45 µm, preferably less than 20 µm. The filler preferably constitutes at least 80% of the weight of the engineered stone, preferably more than 85%, and more preferably more than 90%. According to another embodiment of the invention, the filler can be in the form of aggregates, grains, and / or granules having a particle size distribution between 0.1 mm and 6.5 mm, preferably between 0.1 mm and 2 mm, and between 0.1 mm and 0.7 mm. In the most preferred embodiment, the filler is composed of a combination of powder and granules, for example, the combination may contain at least 60 wt% grains and / or granules and between 20 and 35 wt% powder, wherein, for example, the grains have a particle size distribution between 0.1 mm and 6.5 mm and the powder has an average particle size of less than 45 µm, preferably less than 20 µm.

[0026] According to any of the possibilities mentioned above, the adhesive forming the first layer and / or the second layer of engineered stone comprises, preferably substantially, the following: polyester resin, preferably unsaturated polyester resin. Subsequent preferred alternative solutions for the adhesive include acrylic resin, epoxy resin, polyurethane, rubber, vinyl ester resin, etc. The adhesive is preferably less than 20% by weight of the engineered stone, preferably less than 15%, and more preferably less than 10%.

[0027] Depending on any of the possibilities mentioned above, the engineered stone forming the first and / or second layer may contain additives, such as coupling agents, catalysts, or reagents, to activate or accelerate the curing of the adhesive, and / or temporary binders, such as glues or thermoplastic resins used as temporary binders. In a most preferred embodiment, these additives include at least one silane coupling agent. Furthermore, the additives may include crosslinking agents and / or catalysts to activate and / or accelerate the curing of the adhesive.

[0028] According to any of the possibilities mentioned above, the engineered stone forming the first and / or second layer may contain one or more colorants. The colorants may be in the form of dyes or pigments. Pigments are generally preferred because they provide better UV resistance to the final engineered stone. Pigments may be organic or inorganic, with the latter being even more preferred because UV resistance is further improved. Preferred colors for the colorants are black, yellow, white, red, and green. The one or more colorants may be distributed in various forms within the engineered stone to form decorative patterns that may be random or predetermined.

[0029] The decorative element has a substantially flat shape, like a slab, tile, or flat panel. In the most preferred embodiment, the decorative element is a flat panel, wherein the panel is intended to be substantially rectangular and flat, preferably comprising a surface area of ​​at least 1.5 square meters. In this way, the decorative element is of a sufficiently large shape to be versatile and adaptable to be cut according to the size and shape of the engineered stone itself at its final destination, such as a kitchen or bathroom countertop. According to a preferred embodiment, the panel has a length of at least 2 m, preferably at least 2.5 m, for example 3 m or greater, and a width of at least 1 m, preferably 1.5 m or greater. Furthermore, the panel preferably exhibits a thickness of at least 10 mm, preferably at least 20 mm (e.g., 30 mm). Preferably, the first and second layers can have different thicknesses. In this way, the thickness configuration can be arranged in a manner that maximizes the effect provided by any layer and by a specific combination of thicknesses.

[0030] According to a second independent aspect of the present invention, the present invention relates to a method for manufacturing decorative elements, the method comprising the following steps:

[0031] - Prepare a first mixture comprising at least a filler composition and a binder for forming a first engineered stone;

[0032] - Prepare a second mixture comprising at least a filler composition and a binder for forming a second engineered stone;

[0033] - The first mixture is fed onto a carrier on the production line to form the first layer;

[0034] - The second mixture is provided to a carrier on the production line to form a second layer;

[0035] - Press the first and second mixtures;

[0036] -The adhesive of the first and second mixtures is cured to obtain the engineered stone that forms the decorative element.

[0037] Decorative elements obtained through the method of the second independent aspect may be based on the first independent aspect. Furthermore, decorative elements obtained through the method of the second independent aspect may include one or more features described with respect to the first independent aspect. Similarly, filler compositions, engineered stone, and adhesives may include one or more features incorporating the features described in the first independent aspect.

[0038] In a preferred embodiment, the carrier may include a mold having at least a bottom and sidewalls to receive the mixture. The carrier may also include a lid to close the mold. In some embodiments, the mold and lid may be made of rubber. In some embodiments, the carrier may include one or more sheets of paper. The mold may have a shape and size similar to the shape and size of the final decorative element.

[0039] Preferably, the pressing step is performed under vacuum, i.e., a vacuum is created in the mold to help extract air between the particles of the mixture. More preferably, vibration is applied to the mold or frame during the pressing step, thereby aiding in the pressing of the mixture particles and significantly reducing the porosity of the engineered stone. According to a preferred embodiment, both vacuum and vibration are applied to the mixture during the pressing process. In this way, it is possible to obtain a very high density of the mixture, resulting in a very low porosity after curing.

[0040] Following the pressing step, the mixture in the mold is transported to a curing station. Curing of the adhesive can be achieved by radiation, heating, chemical curing, or other suitable techniques. In a preferred embodiment, the curing step is carried out at a temperature below 500°C, for example, below 200°C, such as at room temperature. In particular, in a preferred embodiment, the curing step can be thermally activated and continued in an exothermic reaction. Activation of the adhesive curing can be carried out at a temperature below 100°C.

[0041] After curing, the engineered stone contains less than 1% porosity by volume, more preferably less than 0.5% porosity by volume, and even more preferably less than 0.2% porosity by volume.

[0042] After curing, the engineered stone is removed from the mold. In some embodiments, the engineered stone is cooled and / or conditioned before proceeding to further steps.

[0043] After curing, the method may include calibration and / or squareing steps. Calibration and squareing are machining steps that have a range of applications in giving the engineered stone the final desired shape and dimensions. Specifically, calibration has the range of applications in flattening one or both main surfaces of a slab made of engineered stone.

[0044] The mixture can be provided in various forms, such as as a paste or mud, although a dry form, such as incoherent particulates, is preferred. It should be noted that the adhesive can be provided in solid or liquid form in its uncured state. Furthermore, the uncured adhesive can exhibit some adhesive behavior that tends to bind the filler particles together.

[0045] In a preferred embodiment, the method includes the step of pre-pressing at least one of the first mixture and the second mixture before providing the first mixture or the second mixture to the carrier. Pre-pressing the mixture helps to obtain decorative elements with a thickness and flatness closer to the desired thickness and flatness in the final product, thereby reducing the amount of waste during subsequent calibration or polishing processes. Preferably, the pre-pressing can be obtained in a continuous process, wherein the mixture is pressed using one or more rollers (e.g., between two opposing rollers).

[0046] In some embodiments of the invention, only one of the first and second mixtures is pre-pressed, while the other mixture is not pre-pressed before being provided to the mold. The inventors have discovered that this pre-pressing can cause stretching of the mixture and the pigments contained therein, thus stretching the resulting decoration between the rollers in the direction of travel of the mixture. Due to the combination of the pre-pressed and non-pre-pressed layers, the resulting decorative element can exhibit a non-stretched decoration while displaying some of the advantages of pre-pressing. It should be noted that the non-pre-pressed layer can be disposed on the carrier, forming a layer of thickness that can be at least twice, preferably at least three or four times, the thickness of the same layer after the pressing and / or curing steps.

[0047] In a preferred embodiment, a pre-compressed layer is first applied to the carrier, followed by a non-pre-compressed layer. In this way, the pre-compressed mixture can exhibit a degree of rigidity and / or flatness, which facilitates subsequent operations, as better described below. In other embodiments, a non-pre-compressed layer is first applied to the carrier, followed by a pre-compressed layer.

[0048] The method may include one or more steps for forming a decorative pattern on a decorative element. The decorative pattern may be provided individually or in combination with each other based on multiple measures.

[0049] According to the first measure, a pre-pressed layer is first applied to a carrier, and the method may include the step of printing (preferably inkjet printing) a decorative pattern on the surface of the pre-pressed layer. The inkjet printing may be performed using pigment-containing inks, preferably inorganic pigments, although organic pigments are not excluded.

[0050] According to the second measure, a decorative foil as described in conjunction with the first independent aspect is provided on top of the first layer. Preferably, in this case, the first layer in the carrier is a pre-pressed mixture, and a second mixture is provided after the decorative foil is provided.

[0051] According to the third measure, a first colorant or a first group of colorants may be added to the mixture before and / or during the step of providing the mixture to the carrier. The first colorant or the first group of colorants may be uniformly distributed throughout the mixture block to provide the base color of the engineered stone. In some embodiments, the first colorant or the first group of colorants may be distributed according to a random motif, such as a random veined effect or a dotted effect.

[0052] According to the fourth measure, the second colorant or a second set of colorants can be provided based on a predetermined motif, for example, mimicking the texture or pattern of marble, granite, or any natural stone. In a preferred embodiment, the predetermined pattern can be formed using a computer-controlled machine (e.g., a humanoid robot or a Cartesian robot) equipped with one or more nozzles for dispensing the colorant. The nozzle is attached to a tool that interacts with the surface of the mixture to create a plurality of grooves or holes to receive the colorant. Preferably, the predetermined motif is obtained using a computer-controlled machine (such as those described in WO 2016 / 113652).

[0053] To better illustrate the features of the invention, several preferred embodiments are described below with reference to the accompanying drawings, as examples without any limiting features, wherein:

[0054] Figure 1 A perspective view of a decorative element according to a first embodiment of the present invention is shown;

[0055] Figure 2 Shown at an enlarged scale along Figure 1 The cross section of plane II-II;

[0056] Figure 3 It shows the manufacturing process. Figure 1 Some steps in the method of creating decorative elements;

[0057] Figure 4 The decorative element according to the second embodiment is shown. Figure 2 The view;

[0058] Figure 5 It shows the manufacturing process. Figure 4 Some steps in the method of creating decorative elements;

[0059] Figure 6 The decorative element according to the second embodiment is shown. Figure 2 The view;

[0060] Figure 7 It shows the manufacturing process. Figure 6 Some steps in the method of making decorative elements.

[0061] Figure 1 A decorative element 1 in the form of a flat panel is shown, adapted for use as a countertop, for example, in a kitchen. The decorative element 1 includes an upper surface 2 on which a decorative pattern 3 is visible; in this example, the pattern mimics the texture of marble. The decorative element has a thickness T1 of 20 mm.

[0062] Decorative element 1 is made of engineered stone, wherein the engineered stone comprises an inorganic filler composition and a cured organic adhesive that binds the inorganic filler particles together. The proportion is between 85% and 95% based on the weight of the engineered stone. The adhesive is preferably a thermosetting resin, and more specifically an unsaturated polyester resin, and comprises less than 15% of the weight of the engineered stone.

[0063] As from Figure 2 As can be seen, the decorative element 1 includes a lower first layer 4 and an upper second layer 5. In this example, the thickness T2 of the first layer 4 is greater than the thickness T3 of the second layer 5. For example, the thickness T2 of the first layer 4 is three-quarters or more of the thickness T1 of the decorative element 1.

[0064] The first layer 4 and the second layer 5 are made of first engineered stone and second engineered stone, respectively, differing in that they contain different filler compositions. Specifically, the first engineered stone of the first layer 4 is formed from silica-based minerals (such as feldspar called nepheline) that primarily contain amorphous silica. The second engineered stone of the second layer 5 is formed from silica-based minerals (such as cristobalite) that primarily contain crystalline silica.

[0065] It should be noted that at the interface between the first and second layers 4 and 5, the engineered stone comprises a composition that is a mixture between the first engineered stone and the second engineered stone.

[0066] Decorative pattern 3 is formed in the second layer 5 by a colorant mixed in the second engineered stone and is arranged such that decorative pattern 3 exists throughout the entire thickness T3 of the second engineered stone. The first and second engineered stones forming the first layer 4 and the second layer 5 may contain a second colorant having the same or similar color. For example, the first layer 4 and the second layer 5 are white and the second layer 5 contains only a black texture formed by a first colorant present only in the second layer 5.

[0067] Figure 3 It shows the method for forming Figure 1 and Figure 2 Some steps of the method for making decorative elements. In a step not shown, a first mixture and a second mixture for forming a first engineered stone and a second engineered stone are prepared, wherein the mixture comprises a corresponding filler composition, a binder, one or more additive coupling agents (e.g., catalysts or reagents for activating or accelerating the hardening of the binder), and a desired colorant.

[0068] The method includes a first step S1, wherein a first mixture 10 for forming a first engineered stone is deposited from a first hopper 11 onto a first belt 12, the first belt conveying the first mixture 10 through at least a pair of rollers 13, which pre-press the first mixture 10 and form a strip of pre-pressed first mixture 10 delivered in a mold 14. The mold is a rubber mold.

[0069] The method then includes a second step S2, in which a second mixture 15 is provided from a second hopper 16 into a mold 14 and positioned above the first mixture 10. It should be noted that the second mixture 15 is not pre-pressed before being fed into the mold 14.

[0070] The method then includes a decorative step S3 for forming the decorative pattern 3. Specifically, once the second mixture 15 is in the mold 14, the robotic arm 17 delivers a second colorant to the second mixture 15 according to a predetermined pattern to form the decorative pattern 3. Specifically, the robotic arm 17 is adapted to carve grooves in the second mixture 15 in the mold 14 and deliver colorant into the grooves, or to premix a certain amount of the second mixture 15 with the second colorant and deliver it into the grooves.

[0071] The mold 14 containing mixtures 10 and 15 advances in the forward direction A to the pressing station 19 for pressing step S4. The pressing station 19 includes a vibration unit 20 and a vacuum unit 21 for applying vibration and vacuum to the mixtures 10 and 15 in the mold 14.

[0072] Then, mold 14 is transferred to curing station 22, where the adhesive is cured in curing step S5. The curing of the adhesive is activated at a temperature below 200°C, and then continues as an exothermic reaction.

[0073] Following the curing step S5, an engineered stone slab 23 is obtained, which is now made of an adhesive material with a porosity of less than 0.2%. The slab 23 is then removed from the mold 15 and transported to several machining stations for finishing operations.

[0074] In step S6, the calibration plate 23 is calibrated to flatten the plate itself. The calibration process is improved due to the pre-pressing operation, resulting in less waste. This is particularly advantageous when combined with the first mixture 10, which is rich in potentially relatively expensive amorphous silica.

[0075] Subsequently, in step S7, the plate 23 is polished to achieve the final surface appearance and to obtain the decorative element 1.

[0076] Figure 4 A second embodiment is shown, wherein the second layer 5 is transparent. In this example, the second engineered stone forming the second layer 5 is free of colorants and comprises a filler composition, wherein the inorganic filler, such as quartz, is transparent and has a selected refractive index, and the adhesive is transparent and has the same refractive index as the filler composition.

[0077] exist Figure 4 In one example, the decorative element 1 includes an intermediate layer 6, which is in the form of a decorative foil with a printed pattern, forming a decorative pattern 3, which is visible through the second layer 5.

[0078] Figure 5 It shows the manufacturing process. Figure 4 Some steps in the method of decorative element 1. Figure 5 Methods and Figure 3 The difference in the method is that the decoration step S3 is performed before step S2, which involves providing the second mixture 15 into the mold 14. Furthermore, in Figure 5 In the method, the decoration step S3 involves providing a decorative foil 6 from a roller 24 above the first mixture 10 in the mold 14. The decorative foil 6 may be a paper foil impregnated with polyester resin or a foil made of polyester. The printed pattern on the decorative foil may be printed in a separate operation by inkjet printing or gravure printing.

[0079] Figure 6 and Figure 4 The difference in the embodiment is that the decorative pattern 3 is printed directly in the engineered stone and an intermediate layer 6 is formed at the interface between the first layer 4 and the second layer 5 formed by the engineered stone in which the pigment is distributed.

[0080] Figure 7 It shows the manufacturing process. Figure 6 Some steps in the method of decorative element 1. Figure 7 Methods and Figure 6 The difference in the method is that the decoration step S3 is performed by directly inkjet printing the decorative pattern 3 on the first mixture in the mold 14 using an inkjet printer 25.

[0081] Furthermore, as is apparent from the contents of this specification, the invention relates to one or more of the following provisions:

[0082] 1. A decorative element comprising a first layer made of engineered stone, wherein the engineered stone comprises an inorganic filler bonded by means of an adhesive, preferably a cured thermosetting resin, wherein the decorative element comprises a second layer disposed above the first layer, and wherein the second layer is made of engineered stone.

[0083] 2. - Decorative elements according to Clause 1, wherein the first and second layers may display:

[0084] -Different particle size distributions of inorganic fillers; and / or

[0085] -Different chemical and / or mineralogical compositions of inorganic fillers; and / or

[0086] -Different adhesive compositions; and / or

[0087] - Different colors, for example, one of these layers can be transparent or semi-transparent; and / or

[0088] -Different thicknesses. Primarily composed of minerals different from those containing crystalline silica.

[0089] 3. - A decorative element according to any of the preceding clauses, wherein at least one of the first layer and the second layer may have a first filler composition, the first filler composition being primarily composed of a mineral different from the mineral containing crystalline silica, and the other layer may have a second filler composition, the second filler composition being primarily composed of a mineral containing crystalline silica.

[0090] 4. - The decorative element according to Clause 3, wherein the first filler composition comprises less than 50% by weight of crystalline silica, preferably less than 10% by weight of crystalline silica, more preferably crystalline silica content without crystalline silica; and / or the second filler composition comprises more than 50% by weight of crystalline silica, more preferably more than 90% by weight of crystalline silica.

[0091] 5. - The decorative element according to Clause 3 or 4, wherein the first filler composition may contain amorphous silica, feldspar, calcium-containing minerals, or other minerals different from those containing crystalline silica.

[0092] 6. - A decorative element according to any one of Clauses 3 to 5, wherein the first filler composition may consist of at least 50% by weight, preferably at least 75% by weight, more preferably at least 90% by weight, or even entirely of amorphous silica, feldspar, calcium-containing minerals, or other minerals different from those containing crystalline silica.

[0093] 7. A decorative element according to any one of clauses 3 to 6, wherein the second filler composition may contain silica-based minerals, most preferably quartz and / or cubic quartz.

[0094] 8. Decorative elements according to clauses 3 to 7, wherein the second layer shows a thickness equal to or less than that of the first layer.

[0095] 9. The decorative element according to clauses 3 to 8, wherein the first layer and the second layer are configured such that, based on the total weight of the decorative element, the total content of crystalline silicon dioxide in the decorative element is less than 50%, preferably less than 30%, and more preferably less than 25%.

[0096] 10. - For decorative elements pursuant to any of the foregoing clauses, at least one of the first layer and the second layer may be transparent or translucent.

[0097] 11. Decorative elements according to Clause 10, wherein the transparent or translucent layer is free of pigment.

[0098] 12. - Decorative elements according to clause 10 or 11, wherein the transparent or translucent layer may have a thickness of less than 3 mm, more preferably less than 2 mm.

[0099] 13. - A decorative element according to any one of claims 10 to 12, comprising an intermediate layer between the first layer and the second layer.

[0100] 14. - Decorative elements according to Clause 13, wherein the intermediate layer includes decorative foil.

[0101] 15. - A decorative element according to Clause 14, wherein the decorative foil may comprise a polymer-based sheet or a paper-based sheet having a printed decoration on the top of the sheet.

[0102] 16. - A decorative element according to any one of claims 1 to 12, comprising a printed pattern substantially between the first decorative layer and the second decorative layer.

[0103] 17. - A decorative element according to Clause 16, wherein the printed pattern is printed on the surface between the first layer and the second layer.

[0104] 18. - A decorative element according to any of the foregoing clauses, wherein the resin is formed at less than 15% of the weight of the engineered stone, and / or wherein the inorganic filler is formed at between 85% and 95% of the weight of the engineered stone.

[0105] 19. Decorative elements according to any of the foregoing clauses, wherein the adhesive may be a thermosetting resin, preferably an unsaturated polyester.

[0106] 20. - Decorative elements according to any of the foregoing clauses, wherein the engineered stone may also include other additives, such as crosslinking agents, coupling agents and pigments.

[0107] 21. - A decorative element according to any of the foregoing clauses, wherein the decorative element is in the form of a flat plate.

[0108] 22. A method for manufacturing decorative elements, the decorative elements being made of engineered stone preferably in accordance with any of the preceding clauses, the method comprising the steps of:

[0109] Prepare a first mixture comprising at least a first inorganic filler composition and a binder;

[0110] Prepare a second mixture comprising at least a second inorganic filler composition and a binder;

[0111] The first mixture is fed onto a carrier on the production line to form the first layer;

[0112] The second mixture is fed onto a carrier on the production line to form a second layer;

[0113] Press the first mixture and the second mixture;

[0114] The adhesive of the first and second mixtures is cured to obtain the engineered stone that forms the decorative element.

[0115] 23. The method according to Clause 22, wherein the step of pressing the mixture may include a vibratory vacuum pressing step.

[0116] 24. The method according to clause 22 or 23, wherein the curing step includes polymerization and / or crosslinking reactions, preferably the curing is thermally activated at a temperature below 200°C.

[0117] 25. The method according to any one of clauses 22 to 24, wherein the carrier may include a mold having at least a bottom wall and side walls for receiving the mixture, and the carrier may also include a lid for closing the mold.

[0118] 26. - The method according to Clause 25, wherein the mold and the lid may be made of rubber.

[0119] 27. - The method pursuant to any of Clauses 22 to 24, wherein the carrier may include one or more paper sheets.

[0120] 28. The method according to any of the clauses 22 to 27, wherein after the curing step, the method may include one or more of the following steps: calibration, polishing, squareing.

[0121] 29. A method according to any one of clauses 22 to 28, wherein the method comprises the step of pre-pressing at least one of the first mixture and the second mixture before providing the first mixture or the second mixture to a carrier.

[0122] 30. A method for manufacturing decorative elements made of engineered stone, the method comprising the following steps:

[0123] Prepare a first mixture comprising at least inorganic fillers and binders;

[0124] Prepare a second mixture comprising at least inorganic fillers and binders;

[0125] The first mixture is fed onto a carrier on the production line to form the first layer;

[0126] The second mixture is fed onto a carrier on the production line to form a second layer;

[0127] Press the first mixture and the second mixture;

[0128] The adhesive of the first and second mixtures is cured to obtain engineered stone that forms decorative elements;

[0129] The method includes the step of pre-pressing at least one of the first mixture and the second mixture before providing the first mixture or the second mixture to the carrier.

[0130] 31. - The method according to clause 30, wherein the pre-pressing can be obtained in a continuous process, wherein the mixture is pressed using one or more rollers (e.g., between two opposing rollers).

[0131] 32. The method according to clause 30 or 31, wherein only one of the first mixture and the second mixture is pre-pressed.

[0132] 33. - The method according to Clause 32, wherein the non-pre-pressed layer may be disposed on the carrier to form a layer having a thickness that is at least twice, preferably at least three or four times, the thickness of the same layer after the pressing step and / or curing step.

[0133] 34. The method of Clause 32 or 33, wherein a pre-pressed layer is first applied to the carrier, and a non-pre-pressed layer is then provided on the carrier.

[0134] 35. The method according to clause 32 or 33, wherein a non-pre-pressed layer is first applied to the carrier, and a pre-pressed layer is then provided on the carrier.

[0135] 36. The method according to any one of claims 30 to 35, comprising the step of forming a decorative pattern.

[0136] 37. The method according to Clause 36, wherein the step of forming the decorative pattern is performed between the step of providing the first mixture to the carrier and the step of providing the second mixture to the carrier.

[0137] 38. The method according to clause 36 or 37, wherein, in the case where a pre-pressed layer is first applied to a carrier, the method may include the step of printing (preferably inkjet printing) a decorative pattern on the surface of the pre-pressed layer.

[0138] 39. The method according to Clause 38, wherein inkjet printing may be carried out using ink containing pigment, the pigment being preferably inorganic, although organic pigments are not excluded.

[0139] 40. - The method according to any of the provisions of Clause 37, wherein the decorative foil is disposed on top of the first layer.

[0140] 41. - The method according to any of Clauses 36 or 37, wherein the decorative pattern can be formed by spraying pigment in a first or second layer; and / or by carving grooves in a first or second layer and delivering a colored mixture in the grooves.

[0141] 42. The method according to any one of the clauses 30 to 41, wherein the step of pressing the mixture may include a vibratory vacuum pressing step.

[0142] 43. - The method according to any one of clauses 30 to 42, wherein the curing step includes polymerization and / or crosslinking reactions, preferably the curing is thermally activated at a temperature below 200°C.

[0143] 44. The method according to any one of the clauses 30 to 43, wherein the carrier may include a mold having at least a bottom wall and side walls to contain the mixture, and the carrier may also include a lid to close the mold.

[0144] 45. - The method according to Clause 44, wherein the mold and the lid may be made of rubber.

[0145] 46. ​​- The method according to any one of the clauses 30 to 43, wherein the carrier may include one or more paper sheets.

[0146] 47. The method according to any one of the clauses 30 to 46, wherein, after the curing step, the method may include one or more of the following steps: calibration, polishing, squarening.

Claims

1. A decorative element (1), said decorative element comprising a first layer (4) made of engineered stone, wherein, The engineered stone comprises an inorganic filler bonded by an adhesive and preferably a cured thermosetting resin, characterized in that the decorative element comprises a second layer (5) disposed above the first layer, wherein the second layer is made of engineered stone.

2. The decorative element (1) according to claim 1, characterized in that, The first and second layers (4, 5) show: -Different particle size distributions of inorganic fillers; and / or -Different chemical and / or mineralogical compositions of inorganic fillers; and / or -Different adhesive compositions; and / or - Different colors, for example, one of the layers can be transparent or translucent; and / or - Different thicknesses.

3. The decorative element (1) according to any one of the preceding claims, characterized in that, At least one of the first layer and the second layer (4, 5) has a first filler composition, which is mainly composed of minerals different from those containing crystalline silica, while the other layer has a second filler composition, which is mainly composed of minerals containing crystalline silica.

4. The decorative element (1) according to claim 3, characterized in that, The first filler composition comprises less than 50% by weight of crystalline silica, preferably less than 10% by weight of crystalline silica, and more preferably crystalline silica-free; and / or the second filler composition comprises more than 50% by weight of crystalline silica, more preferably more than 90% by weight of crystalline silica.

5. The decorative element (1) according to claim 3 or 4, characterized in that, The first filler composition comprises amorphous silica, feldspar, calcium-containing minerals, or other minerals different from those containing crystalline silica.

6. The decorative element (1) according to any one of claims 3 to 5, characterized in that, The first filler composition consists of at least 50% by weight, preferably at least 75% by weight, more preferably at least 90% by weight, or even entirely of amorphous silica, feldspar, calcium-containing minerals, or other minerals different from those containing crystalline silica.

7. The decorative element (1) according to any one of claims 3 to 6, characterized in that, The second filler composition comprises silica-based minerals, most preferably quartz and / or cristobalite.

8. The decorative element (1) according to any one of claims 3 to 7, characterized in that, The second layer (5) exhibits a thickness (T3) equal to or less than the thickness (T2) of the first layer (4).

9. The decorative element (1) according to any one of claims 3 to 8, characterized in that, The first layer and the second layer (4, 5) are configured such that, based on the total weight of the decorative element, the total content of crystalline silicon dioxide in the decorative element is less than 50%, preferably less than 30%, and more preferably less than 25%.

10. The decorative element (1) according to any one of the preceding claims, characterized in that, At least one of the first layer and the second layer (4, 5) may be transparent or semi-transparent.

11. The decorative element (1) according to claim 10, characterized in that, The transparent or translucent layers (4, 5) contain no pigment.

12. The decorative element (1) according to claim 10 or 11, characterized in that, The transparent or translucent layer exhibits a thickness of less than 3 mm, more preferably less than 2 mm.

13. The decorative element (1) according to any one of the preceding claims, characterized in that, The decorative element includes a printed pattern (3) that is substantially between the first decorative layer and the second decorative layer.

14. The decorative element (1) according to claim 13, characterized in that, The printed pattern (3) is printed on the surface between the first layer and the second layer (4, 5).

15. The decorative element (1) according to any one of the preceding claims, characterized in that, The adhesive may be a thermosetting resin, preferably an unsaturated polyester.

16. A method for manufacturing a decorative element (1) made of engineered stone according to any one of the preceding claims, the method comprising the steps of: - Prepare a first mixture (10) comprising at least a first inorganic filler composition and a binder; -Preparing a second mixture (15) comprising at least a second inorganic filler composition and a binder; - The first mixture (10) is provided (S1) to a carrier (14) on the production line to form a first layer; - The second mixture (15) is provided (S2) to the carrier (14) on the production line to form a second layer; - Press (S4) the first mixture and the second mixture (10, 15); - The adhesive of the first mixture and the second mixture is cured to obtain the engineered stone that forms the decorative element (1).

17. The method according to claim 16, characterized in that, The pressing (S4) step of the mixture (10, 15) includes a vibratory vacuum pressing step.

18. The method according to any one of claims 16 or 17, characterized in that, The method includes the following steps: pre-pressing at least one of the first mixture (10) and the second mixture (15) before providing the first mixture or the second mixture to the carrier (14).

19. A method for manufacturing a decorative element (1) made of engineered stone, the decorative element preferably being according to any one of claims 1 to 15, the method comprising the following steps: - Prepare a first mixture (10) comprising at least a first inorganic filler composition and a binder; -Preparing a second mixture (15) comprising at least a second inorganic filler composition and a binder; - The first mixture (10) is provided (S1) to a carrier (14) on the production line to form a first layer; - The second mixture (15) is provided (S2) to the carrier (14) on the production line to form a second layer; - Press (S4) the first mixture and the second mixture (10, 15); -The adhesive that cures the first mixture and the second mixture is used to obtain engineered stone that forms the decorative element (1); The method is characterized by comprising the following steps: pre-pressing at least one of the first mixture (10) and the second mixture (15) before providing the first mixture or the second mixture to the carrier (14).

20. The method according to claim 21, characterized in that, Only one of the first mixture and the second mixture is pre-pressed.

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